EP3112754B1 - Waste-feeding apparatus and sealing method thereof - Google Patents
Waste-feeding apparatus and sealing method thereof Download PDFInfo
- Publication number
- EP3112754B1 EP3112754B1 EP16174339.8A EP16174339A EP3112754B1 EP 3112754 B1 EP3112754 B1 EP 3112754B1 EP 16174339 A EP16174339 A EP 16174339A EP 3112754 B1 EP3112754 B1 EP 3112754B1
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- EP
- European Patent Office
- Prior art keywords
- waste
- damper
- gasifier
- feeding
- feeding apparatus
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
- F23G5/02—Incineration of waste; Incinerator constructions; Details, accessories or control therefor with pretreatment
- F23G5/027—Incineration of waste; Incinerator constructions; Details, accessories or control therefor with pretreatment pyrolising or gasifying stage
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
- F23G5/44—Details; Accessories
- F23G5/442—Waste feed arrangements
- F23G5/444—Waste feed arrangements for solid waste
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G5/00—Incineration of waste; Incinerator constructions; Details, accessories or control therefor
- F23G5/50—Control or safety arrangements
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G2201/00—Pretreatment
- F23G2201/80—Shredding
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G2205/00—Waste feed arrangements
- F23G2205/12—Waste feed arrangements using conveyors
- F23G2205/121—Screw conveyor
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G2205/00—Waste feed arrangements
- F23G2205/16—Waste feed arrangements using chute
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G2205/00—Waste feed arrangements
- F23G2205/18—Waste feed arrangements using airlock systems
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G2207/00—Control
- F23G2207/20—Waste supply
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23G—CREMATION FURNACES; CONSUMING WASTE PRODUCTS BY COMBUSTION
- F23G2900/00—Special features of, or arrangements for incinerators
- F23G2900/55—Controlling; Monitoring or measuring
- F23G2900/55006—Measuring material flow rates
Definitions
- the present invention relates to a waste-feeding apparatus according to the preamble of claim 1 and a sealing method according to the preamble of claim 4 for preventing a spark from occurring when double dampers having a sealing function that inhibits external air from entering a gasifier are closed and for preventing magnetized waste or fine waste from adhering to the dampers.
- the gasification and melting furnace gasifies the waste, such as sludge and municipal waste, in a gasifier (at temperatures from 500°C to 600°C), and decomposes the waste into combustible gas, fixed carbon, and ash.
- the decomposed combustible gas and fixed carbon are burned in a melting furnace.
- the temperature in the melting furnace is increased to 1300°C or higher to melt the ash.
- molten slag is cooled, for example, with water to produce water-cooled slag.
- a waste-feeding apparatus that feeds waste to a gasifier requires volumetric feeding performance of the waste, and sealing performance.
- FIG. 7 illustrates the general configurations of a fluidized-bed gasifier and a combustible-substance-feeding apparatus (hereinafter, referred to as a waste-feeding apparatus) that feeds a combustible substance (hereinafter, referred to as waste) to the fluidized-bed gasifier, according to related art.
- a waste-feeding apparatus a combustible-substance-feeding apparatus that feeds a combustible substance (hereinafter, referred to as waste) to the fluidized-bed gasifier, according to related art.
- a fluidized-bed gasifier (hereinafter, referred to as gasifier) 50 includes a waste-feeding mechanism 62 at a waste inlet 53 in the gasifier 50, a chute 63 connected with the waste-feeding mechanism 62, and a conveyor 65 connected with the chute 63.
- the waste-feeding mechanism 62 includes a screw conveyor 64 that is driven by a motor 68.
- the chute 63 includes double dampers 59.
- Waste 54 fed into a hopper 66 by a crane 61 or the like is lifted through the conveyor 65, and fed into an upper opening of the chute 63 from the distal end of the conveyor 65.
- the waste 54 fed into the chute 63 is intermittently fed into the waste-feeding mechanism 62 by the operation of the double dampers 59 having a sealing function.
- the screw conveyor 64 in the waste-feeding mechanism 62 reduces the intermittency of the intermittently fed waste 54 and allows the waste 54 to be fed into the gasifier 50 continuously by a predetermined constant amount (in a volumetric manner).
- the waste 54 fed into the gasifier 50 is gasified in a reducing atmosphere in a fluidized bed 51 being fluidized with fluidizing gas 52 blown from a wind box at the bottom.
- Produced gas 57 produced through the gasification exits from the fluidized bed 51, passes through a freeboard 55, and is guided to a melting furnace (not shown) through a produced-gas outlet 56.
- the waste 54 which has been intermittently fed from the chute 63, is continuously fed by a substantially constant amount (in a volumetric manner) by the effect of the screw conveyor 64 in the waste-feeding mechanism 62.
- control for stable gasification operation of the gasifier 50 such as control for feeding the fluidizing gas 52 and control for the temperature in the furnace, is easily carried out.
- Prior art JP 2003 056822 discloses a waste feeding apparatus according to the preamble of claim 1 and a sealing method of a waste feeding apparatus.
- the waste-feeding mechanism 62 for the gasifier 50 includes the double dampers having an upper damper and a lower damper, which are alternately opened and closed, in the chute 63, the waste-feeding mechanism 62 has good sealing performance. Also, since the waste-feeding mechanism 62 includes the screw conveyor 64, the waste-feeding mechanism 62 has good volumetric feeding performance for the waste 54 to the gasifier 50. However, the waste-feeding mechanism 62 for the gasifier 50 according to the related art does not have sufficient volumetric feeding performance for the waste 54.
- the waste-feeding apparatus for the gasifier has the good sealing performance and good volumetric feeding performance for the waste to the gasifier.
- a damper is typically made of a SS member or a SUS member having good resistance to corrosion.
- a spark may occur due to an impact exerted when the damper is closed. For example, oil contained in the waste may be ignited with the spark.
- the damper when the damper is made of the SS member, magnetized waste may adhere to the damper, and another magnetized waste may be hooked to the adhering magnetized waste, resulting in the waste being accumulated. It is difficult to smoothly feed the waste to the gasifier. Further, when the damper is made of metal, the metal damper has a high friction coefficient. Hence, wet fine waste may adhere to the damper. The sealing performance may be deteriorated.
- the waste-feeding apparatus for the gasifier according to the related art has the good sealing performance and good volumetric feeding performance for the waste to the gasifier.
- the sealing performance cannot be maintained.
- the operation of the waste-feeding apparatus has to be stopped, and the waste caught by the damper has to be removed through, for example, an access hole provided in the chute. This may decrease the operating ratio of the waste-feeding apparatus, and a troublesome work is needed for removing the waste.
- the following operation is carried out to prevent the waste from being caught by the damper.
- the object of the present invention is to further improve a waste-feeding apparatus according to the preamble of claim 1 and a sealing method according to the preamble of claim 4 so as to prevent a spark from occurring when double dampers having a sealing function that inhibits external air from entering a gasifier are closed and so as to prevent magnetized waste or fine waste from adhering to the dampers.
- the object is achieved by a waste-feeding apparatus having the features of claim 1 and by a sealing method having the features of claim 4.
- the waste-feeding apparatus includes a vertical chute and a waste-conveying device.
- the vertical chute includes upper and lower dampers separated from one another by a predetermined distance in an up-down direction, the upper and lower dampers having a sealing function that inhibits external air from entering a gasifier and configured to be alternately opened and closed.
- the waste-conveying device is configured to convey waste, which has been fed through the vertical chute, toward the gasifier.
- the upper and lower dampers have damper bodies, each of the damper bodies having a damper substrate and a hard low-friction resin plate fixed to an upper surface of the damper substrate by mechanical fastening means. When the upper or lower damper is closed, an upper surface of an outer edge portion of the hard low-friction resin plate contacts a sealing surface formed on an inner side of the vertical chute.
- the mechanical fastening means may be a small flat-head screw that is screwed into an internal thread formed in the damper substrate such that an upper surface of a screw head is lower than an upper surface of the hard low-friction resin plate.
- a resin coating layer may be formed on the upper surface of the screw head.
- a sealing method of a waste-feeding apparatus for inhibiting external air from entering a gasifier according to the present invention includes a vertical chute and a waste-conveying device.
- the vertical chute includes upper and lower dampers separated from one another by a predetermined distance in an up-down direction.
- the waste-conveying device is configured to convey waste, which has been fed through the vertical chute, toward the gasifier.
- the sealing method includes the step of, when the upper and lower dampers are alternately closed for sealing, bringing an upper surface of an outer edge portion of a hard low-friction resin plate of a damper body in each of the upper and lower dampers into contact with a sealing surface formed on an inner side of the vertical chute.
- the inventors have learned that, if the upper and lower dampers are opened and closed at an interval of, for example, 15 seconds, each damper is opened and closed 240 times per hour, however, the number of times the waste is caught by the upper damper per hour is no more than two (1/120).
- the inventors have assumed that the aforementioned problems (1) and (2), described in Description of the Related Art, can be markedly improved if the unnecessary starting and stopping of the upstream devices by 238 times are omitted.
- the inventors have implemented the waste-feeding method according to a comparative example not part of the invention.
- the phenomenon that the number of times the waste is caught by the upper damper per hour is not more than two can be attained by the following reasons.
- a block of waste roughly crushed by a crusher is dropped and fed onto the upper damper at a certain individual interval, and hence the block of waste is less frequently dropped at a predetermined position simultaneously when the upper damper is closed. Also, as the apparatus is operated for a long term, a muddy substance may adhere onto the lower damper.
- the lower damper includes the lower left damper and the lower right damper configured to be opened and closed through the supporting shafts.
- the supporting shafts are provided on the opposite portions of the inner wall of the vertical chute and parallel to the center line.
- the center line extends in the longitudinal direction and passing through the center in the width direction of the waste-conveying device.
- the merged line defined by the distal portions of the lower left damper and the lower right damper in the closed state is located above the center line.
- the waste-feeding method includes the steps of, after the upper damper is closed, opening the lower damper around the supporting shafts as the pivots, the supporting shafts being provided on the opposite portions of the inner wall of the vertical chute and parallel to the center line, the center line extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device; and dropping the waste, which has been received while the upper damper is opened, toward the center line to convey the waste by the waste-conveying device.
- the waste having the length corresponding to the length of the lower damper in a direction toward the gasifier is fed to the waste-conveying device.
- the waste is dropped at the center in the width direction of the waste-conveying device immediately after the lower left damper and the lower right damper start to be opened.
- the opening becomes larger, the area in which the waste is dropped becomes larger in a direction away from the center in the width direction.
- the waste on the waste-conveying device has a cross section in a mound-like shape at any position in the longitudinal direction toward the gasifier.
- the variation in volume of the waste in the left-right direction can be reduced.
- the volumetric feeding performance of the waste to the gasifier is improved.
- the lower left damper and the lower right damper of the lower damper may be lowered toward the distal portions from the supporting shafts in the closed state.
- the upper surfaces of the lower left damper and the lower right damper are inclined in the closed state, and hence have a hopper-like shape. The waste can be efficiently fed onto the waste-conveying device when the lower left damper and the lower right damper start to be opened.
- the waste-conveying device may be the screw conveyor including the pair of conveyance screws having the rotation centers parallel to one another in the horizontal plane.
- the waste having the length corresponding to the length of the lower damper in a direction toward the gasifier is fed from the lower damper to an area between the pair of conveyance screws of the screw conveyor.
- the waste disintegrator may be provided at the forward position of the distal end of the screw conveyor, the waste disintegrator configured to disintegrate the waste conveyed by the screw conveyor.
- the waste-feeding method according to the comparative example not part of the invention may further include the step of feeding the waste, which has been conveyed by the waste-conveying device, into the gasifier while disintegrating the waste by the waste disintegrator.
- the waste disintegrator disintegrates the waste, which has been conveyed by the screw conveyor or the waste-conveying device, the volumetric feeding performance of the waste can be further improved.
- the upper surface of the outer edge portion of the hard low-friction resin plate on the damper body in each of the upper and lower dampers provided in the vertical chute of the waste-feeding apparatus contacts the sealing surface formed on the inner side of the vertical chute.
- the upper or lower damper when the upper or lower damper is closed, the upper surface of the outer edge portion of the hard low-friction resin plate contacts the sealing surface formed on the inner side of the vertical chute. Accordingly, even when the sealing surface formed on the vertical chute is made of metal, a spark does not occur. Further, magnetized waste does not adhere to the hard low-friction resin plate. Also, since the hard low-friction resin plate has a low friction coefficient, wet fine waste does not adhere to the hard low-friction resin plate. Hence, the sealing performance is not deteriorated.
- the hard low-friction resin plate may be attached to the damper substrate by the small flat-head screw (the mechanical fastening means). Accordingly, the hard low-friction resin plate can be easily attached to and detached from (replaced in) the damper substrate.
- the resin coating layer may be formed on the upper surface of the screw head of the small flat-head screw. Accordingly, magnetic substances can be prevented from adhering to the screw head of the small flat-head screw, and corrosive substances can be prevented from contacting the screw head.
- the waste-feeding method includes the steps of, if the damper-closed signal is not received although the upper cylinder, which opens and closes the upper damper, has been operated to close the upper damper, determining that the waste is caught by the upper damper, and temporarily stopping feeding of the waste to the vertical chute; during the stop of the feeding of the waste, opening the upper damper to remove the caught waste, and closing the open upper damper; and if the damper-closed signal is received, determining that the waste caught by the upper damper has been removed, and starting the feeding of the waste to the vertical chute.
- the waste-feeding method according to the further comparative example not part of the invention may further include the steps of starting counting an elapsed time by a timer since the operation of the upper cylinder to close the upper damper has started; and if the damper-closed signal is not output although a predetermined period has elapsed, stopping the counting, and determining that the waste is being caught by the upper damper.
- the waste-feeding method according to the further comparative example not part of the invention the unused stop period of the waste-feeding apparatus can be decreased.
- the time required for removing the waste caught by the upper damper can be decreased.
- the damper-closed signal of the upper damper may be output from the limit switch that detects the stroke of the upper cylinder.
- the limit switch that detects the stroke of the upper cylinder.
- the waste-feeding method may further include the steps of, if the damper-closed signal is not received although a lower cylinder, which opens and closes the lower damper, has been operated to close the lower damper, determining that the waste is caught by the lower damper, opening the lower damper to remove the caught waste, and closing the lower damper; and if the damper-closed signal is received, determining that the waste, which has been caught by the lower damper, is removed, and opening the upper damper.
- the waste-feeding method in addition to the advantages of the above waste-feeding method, it can be recognized that the waste is caught by the lower damper. Also, the waste caught by the lower damper can be reliably removed. The waste is not accumulated and stayed on the lower damper as a result of the waste being caught by the lower damper, and the waste can be reliably conveyed by the waste-conveying device and fed into the waste inlet. Accordingly, the volumetric feeding performance for the waste is hardly deteriorated, and the processing efficiency for the waste can be increased.
- the waste-feeding method according to the further comparative example not part of the invention may further include the steps of starting counting an elapsed time by a timer since the operation of the lower cylinder to close the lower damper has started; and if the damper-closed signal is not output although a predetermined period has elapsed, stopping the counting, and determining that the waste is being caught by the lower damper.
- the waste-feeding method according to the further comparative example not part of the invention the unused stop period of the waste-feeding apparatus can be decreased.
- the time required for removing the waste caught by the lower damper can be decreased.
- the damper-closed signal of the lower damper may be output from the limit switch that detects the stroke of the lower cylinder.
- the limit switch that detects the stroke of the lower cylinder.
- FIG. 1 is an explanatory view schematically showing the configuration of a waste-feeding apparatus according to the comparative example.
- Fig. 2A is a cross-sectional view taken along line A-A in Fig. 1
- Fig. 2 being an explanatory view showing the open and closed conditions of upper and lower dampers and showing the shape of waste fed by a pair of conveyance screws of a screw conveyor (a waste-conveying device).
- Fig. 2B is a cross-sectional view taken along line B-B in Fig. 1
- Fig. 2B being an explanatory view showing the plan state of the waste conveyed by the pair of conveyance screws of the screw conveyor.
- the waste-feeding apparatus 1 includes a vertical chute 6 (described below), a waste-conveying device 7 to which waste 9 is fed from the vertical chute 6, and a waste-feeding chute 8 connected with the waste-conveying device 7.
- the waste-feeding chute 8 obliquely extends and communicates with a waste inlet 21 in a gasifier 20, to feed the waste 9.
- a waste-dumping device such as a crane feeds the waste 9 into a waste hopper 2.
- a pusher 3 pushes the waste 9.
- a crusher 4 roughly crushes the pushed waste 9.
- a conveyor 5 provided in an air-tight conveyor housing lifts the waste 9, which has been roughly crushed by the crusher 4, obliquely upward.
- the waste 9 is dropped and fed into the vertical chute 6.
- the vertical chute 6 includes double dampers having a sealing function, which will be described later.
- the double dampers each have a rectangular cross section.
- the waste-conveying device 7 is connected with the lower end of the vertical chute 6.
- the waste-conveying device 7 includes a screw conveyor and a waste disintegrator, which will be described later.
- the screw conveyor conveys the waste 9 toward the gasifier 20.
- the upper end of the waste-feeding chute 8 is connected with the lower distal end of the waste-conveying device 7.
- the waste-feeding chute 8 extends obliquely downward and communicates with the waste inlet 21 of the gasifier 20.
- the double dampers provided in the vertical chute 6 include an upper damper 11 and a lower damper 12.
- the lower damper 12 is provided below the upper damper 11 and separated from the upper damper 11 by a predetermined distance.
- the upper and lower dampers 11 and 12 are configured as shown in Fig. 2 .
- the configuration of the upper damper 11 will be described first.
- the upper damper 11 includes an upper left damper 11 L and an upper right damper 11 R .
- the upper left damper 11 L is opened and closed through an upper supporting shaft 11p.
- the upper supporting shaft 11p is parallel to a center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7.
- the upper supporting shaft 11p is provided on a left portion of the inner wall of the vertical chute 6 in a view facing the gasifier 20.
- the upper right damper 11 R is opened and closed through an upper supporting shaft 11p.
- the upper supporting shaft 11p is parallel to the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7.
- the upper supporting shaft 11p is provided on a right portion of the inner wall of the vertical chute 6 in a view facing the gasifier 20.
- a merged line 11m is defined when the upper left damper 11 L and the upper right damper 11 R are closed and distal portions of the upper left damper 11 L and the upper right damper 11 R contact one another, the distal portions being straight and facing one another.
- the merged line 11m is located at the center in the left-right direction of the vertical chute 6, that is, at a position above the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7.
- the upper left damper 11 L and the upper right damper 11 R are closed, the upper left damper 11 L and the upper right damper 11 R are lowered toward the distal portions from the upper supporting shafts 11p.
- the upper left damper 11 L and the upper right damper 11 R define an angle ⁇ of, for example, 150°.
- the upper damper 11 has the two dampers including the upper left damper 11 L and the upper right damper 11 R .
- the upper damper 11 may have a single damper and may be opened and closed through an upper supporting shaft provided on the inner wall of the vertical chute 6 at a position close to the gasifier 20.
- the lower damper 12 includes a lower left damper 12 L and a lower right damper 12 R .
- the lower left damper 12 L is opened and closed through a lower supporting shaft 12p.
- the lower supporting shaft 12p is parallel to the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7.
- the lower supporting shaft 12p is provided on a left portion of the inner wall of the vertical chute 6 in a view facing the gasifier 20.
- the lower right damper 12 R is opened and closed through a lower supporting shaft 12p.
- the lower supporting shaft 12p is parallel to the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7.
- the lower supporting shaft 12p is provided on a right portion of the inner wall of the vertical chute 6 in a view facing the gasifier 20.
- a merged line 12m is defined when the lower left damper 12 L and the lower right damper 12 R are closed and distal portions of the lower left damper 12 L and the lower right damper 12 R contact one another, the distal portions being straight and facing one another.
- the merged line 12m is located at the center in the left-right direction of the vertical chute 6, namely, at a position above the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7.
- the lower left damper 12 L and the lower right damper 12 R are closed, the lower left damper 12 L and the lower right damper 12 R are lowered toward the distal portions from the lower supporting shafts 12p.
- the lower left damper 12 L and the lower right damper 12 R define an angle ⁇ of, for example, 150°.
- the upper surfaces of the lower left damper 12 L and the lower right damper 12 R are inclined in the closed state, and hence have a hopper-like shape.
- the waste 9 can be efficiently fed onto the screw conveyor (described below) when the lower left damper 12 L and the lower right damper 12 R start to be opened.
- the upper damper 11 and the lower damper 12 are alternately opened and closed such that at least one of the upper damper 11 and the lower damper 12 is closed, in order to inhibit external air from entering the gasifier 20.
- the waste-conveying device 7 houses a screw conveyor 13 that conveys the waste 9 fed through the lower damper 12 toward the gasifier 20.
- the screw conveyor 13 includes a pair of conveyance screws 13a having rotation centers parallel to one another in a horizontal plane.
- a waste disintegrator 14 is provided at the distal side of the screw conveyor 13 at a position not occupied by the screw conveyor 13. The waste disintegrator 14 disintegrates the waste 9 pushed by the screw conveyor 13.
- the waste disintegrator 14 in the comparative example is rotary type; however, a configuration of rocking type may be used.
- the operation mode of the waste-feeding apparatus 1 having the above-described configuration will be described below.
- the pusher 3 pushes the waste 9 fed into the waste hopper 2.
- the crusher 4 roughly crushes the pushed waste 9.
- the conveyor 5 lifts the waste 9, which has been roughly crushed by the crusher 4, obliquely upward.
- the waste 9 is dropped and fed onto the upper damper 11 of the vertical chute 6.
- the upper damper 11 When the waste 9 is stacked on the upper damper 11 by a predetermined amount, the upper damper 11 is opened, and then closed after several seconds has elapsed. During this period, the waste 9 stacked on the upper damper 11 by the predetermined amount and the waste 9 lifted obliquely upward by the conveyor 5 are fed onto the upper surface of the lower damper 12. When several seconds has elapsed after the upper damper 11 is closed, the lower damper 12 is opened and the open state is maintained for several seconds. When the waste 9 fed onto the lower damper 12 is fed to the screw conveyor 13, the distal portions of the lower left damper 12 L and the lower right damper 12 R are opened, the distal portions being straight and facing one another. Thus, the waste 9 is dropped on the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7. In particular, the waste 9 is dropped in an area between the pair of conveyance screws 13a of the screw conveyor 13.
- the waste 9 having the length corresponding to the length of the lower damper 12 in a direction toward the gasifier 20 is fed to the pair of conveyance screws 13a of the screw conveyor 13.
- the waste 9 is stacked in a mound-like shape in the width direction of the pair of conveyance screws 13a of the screw conveyor 13.
- the variation in volume of the waste 9 in the left-right direction can be reduced.
- the waste 9 fed to the screw conveyor 13 is conveyed by rotation of the pair of conveyance screws 13a.
- the waste disintegrator 14 disintegrates the waste 9 into smaller pieces.
- the waste 9 is fed into the gasifier 20 through the waste-feeding chute 8 and then through the waste inlet 21.
- the waste 9 fed into the gasifier 20 is gasified at temperatures from 500°C to 600°C, and decomposed into combustible gas, fixed carbon, and ash. Then, the decomposed combustible gas and fixed carbon are burned in a melting furnace (not shown). The ash is molten at temperatures of 1300°C or higher, and becomes molten slag.
- the lower damper 12 is closed when several seconds has elapsed after the waste 9 is fed to the screw conveyor 13. Then, the upper damper 11, which has been previously closed, is opened. In this way, the upper damper 11 and the lower damper 12 are alternately opened and closed at an interval of predetermined seconds.
- the lower damper 12 includes the lower left damper 12 L and the lower right damper 12 R .
- the lower left damper 12 L and the lower right damper 12 R are provided on the opposite portions of the inner wall of the vertical chute 6 and opened and closed through the lower supporting shafts 12p.
- the lower supporting shafts 12p are parallel to the center line Lc.
- the center line Lc extends in the longitudinal direction and passes through the center in the width direction of the waste-conveying device 7.
- the merged line 12m defined by the distal portions of the lower left damper 12 L and the lower right damper 12 R in the closed state is located above the center line Lc.
- the waste 9 having the length corresponding to the length of the lower damper 12 in the direction toward the gasifier 20 can be fed to the screw conveyor 13.
- the waste 9 is dropped at the center in the width direction of the screw conveyor 13 immediately after the lower left damper 12 L and the lower right damper 12 R start to be opened (or the waste 9 is dropped at the position of the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7). That is, the waste 9 is dropped in the area between the pair of conveyance screws 13a. Then, as the opening becomes larger, the area in which the waste 9 is dropped becomes larger in a direction away from the center in the width direction.
- the waste 9 has a cross section in a mound-like shape at any position in the direction toward the gasifier 20 along the pair of conveyance screws 13a of the screw conveyor 13.
- the variation in volume of the waste 9 in the left-right direction can be reduced.
- the volumetric feeding performance of the waste 9 to the gasifier is improved.
- the lower left damper 12 L and the lower right damper 12 R are lowered toward the distal portions from the lower supporting shafts 12p in the closed state.
- the upper surfaces of the lower left damper 12 L and the lower right damper 12 R are inclined in the closed state, and hence have a hopper-like shape.
- the waste 9 can be efficiently fed onto the screw conveyor 13 when the lower left damper 12 L and the lower right damper 12 R start to be opened.
- the waste disintegrator 14, which disintegrates the waste 9 pushed by the screw conveyor 13, is provided at a forward position of the distal end of the screw conveyor 13.
- the waste disintegrator 14 disintegrates the waste 9 conveyed by the rotation of the pair of conveyance screws 13a into smaller pieces.
- the waste 9 is fed into the gasifier 20 through the waste-feeding chute 8 and then through the waste inlet 21.
- a large block of waste 9 will not be fed, contributing to improvement in volumetric feeding.
- toxic substances can be prevented from being produced in exhaust gas, and variation in the amount of produced gas can be reduced.
- the performance of a gasification and melting plant can be improved, and the allowance ratios for respective devices can be decreased. Consequently, the cost of the gasification and melting plant can be decreased.
- the waste-feeding apparatus for the gasifier according to the comparative example is merely a specific example, and the design thereof can be freely changed within the technical scope of the present disclosure.
- the configuration of the waste-feeding apparatus for the gasifier is not limited to the above-described example.
- the waste-feeding apparatus 1 includes the conveyor 5.
- the conveyor may be omitted, and the waste 9 crushed by the crusher 4 may be directly dropped and fed into the vertical chute 6.
- the installation space can be small, and the building for housing the equipment can be small. This is economically advantageous to decrease the equipment cost for the waste-feeding apparatus.
- the crusher 4 may be provided separately from the waste-feeding apparatus 1. With this configuration, even when the crusher 4 is stopped during operation because of a trouble, the waste-feeding apparatus 1 can continuously feed the waste 9 to the gasifier 20. Accordingly, continuous operating performance can be increased.
- FIG. 3 is an explanatory view schematically showing the configuration of a waste-feeding apparatus according to an embodiment of the present invention, Fig. 3 also showing a gasifier for gasification of the waste.
- Fig. 4A is an explanatory view schematically showing the configurations of upper and lower dampers.
- Fig. 4B is an enlarged cross-sectional view showing part C in Fig. 4A .
- Reference numeral 1 shown in Fig. 3 denotes the waste-feeding apparatus according to an embodiment of the invention.
- the embodiment implements the waste-feeding method of the present invention.
- the waste-feeding apparatus 1 includes a vertical chute 6 (described below), a waste-conveying device 7 to which waste 9 is fed from the vertical chute 6, and a waste-feeding chute 8 connected with the waste-conveying device 7.
- the waste-feeding chute 8 obliquely extends and communicates with a waste inlet 21 in a gasifier 20, to feed the waste 9.
- a waste-dumping device such as a crane feeds the waste 9 into a waste hopper 2.
- a pusher 3 pushes the waste 9.
- a crusher 4 roughly crushes the pushed waste 9.
- a conveyor 5 provided in an air-tight conveyor housing lifts the waste 9, which has been roughly crushed by the crusher 4, obliquely upward.
- the waste 9 is dropped and fed into the vertical chute 6.
- the vertical chute 6 includes double dampers having a sealing function, which will be described later.
- the double dampers each have a rectangular cross section.
- the waste-conveying device 7 is connected with the lower end of the vertical chute 6.
- the waste-conveying device 7 includes a screw conveyor and a waste disintegrator, which will be described later.
- the screw conveyor conveys the waste 9 toward the gasifier 20.
- the upper end of the waste-feeding chute 8 is connected with the lower distal end of the waste-conveying device 7.
- the waste-feeding chute 8 extends obliquely downward and communicates with the waste inlet 21 of the gasifier 20.
- the double dampers provided in the vertical chute 6 include an upper damper 11 and a lower damper 12.
- the lower damper 12 is provided below the upper damper 11 and separated from the upper damper 11 by a predetermined distance.
- An upper supporting shaft 11p is provided on the inner wall of the vertical chute 6 at a position close to the gasifier 20.
- the upper damper 11 is rotated downward by 75° around the upper supporting shaft 11p as a pivot from a closed position inclined at 15° to a horizontal line.
- the upper damper 11 is opened to a vertical position at which the upper damper 11 is orthogonal to the horizontal line.
- the lower damper 12 is provided in the vertical chute 6 at the position below the upper damper 11 and separated from the upper damper 11 by a predetermined distance.
- a lower supporting shaft 12p is provided on the inner wall of the vertical chute 6 at a position close to the gasifier 20.
- the lower damper 12 is rotated downward by 75° around the lower supporting shaft 12p as a pivot from a closed position inclined at 15° to a horizontal line.
- the lower damper 12 is opened to a vertical position at which the lower damper 12 is orthogonal to the horizontal line.
- the upper and lower dampers 11 and 12 each have an inclination angle of 15° to the horizontal line in the closed state.
- the inclination angle of the upper and lower dampers to the horizontal line does not have to be 15° and may be properly determined.
- the upper and lower supporting shafts 11p and 12p are provided on the inner wall of the vertical chute 6 at the positions close to the gasifier 20.
- the following arrangement may be employed.
- the waste 9 can be dropped from the upper damper 11 onto a position close to the lower supporting shaft 12p of the lower damper 12.
- a substance adhering to the upper surface of the lower damper 12 is continuously wiped out because the waste 9 dropped from the upper damper 11 slides on the upper surface of the lower damper 12.
- the frequency of cleaning for the lower damper 12 can be reduced.
- the maintenance cost for the waste-feeding apparatus can be decreased.
- the upper and lower dampers 11 and 12 are configured as shown in Figs. 4A and 4B .
- the upper damper 11 includes an upper damper body 11a and an upper supporting arm 11h.
- the upper damper body 11a includes a damper substrate 11b made of, for example, a SS member or a SUS member, and a hard low-friction resin plate 11c fixed to the upper surface of the damper substrate 11b.
- the upper supporting arm 11h has one end that is rotatably supported by the upper supporting shaft 11p, and the other end that rotatably supports the upper damper body 11a through a bracket 11e and a coupling pin 11f.
- the hard low-friction resin plate 11c is fixed to the upper surface of the damper substrate 11b by a plurality of small flat-head screws 11d (mechanical fastening means) that are respectively screwed into a plurality of internal threads 11s formed in the damper substrate 11b.
- coating layers 11g each having an inverted cone shape are provided to fill spaces above the upper surfaces of the small flat-head screws 11d housed in inverted-cone-shaped screw-head housing holes in the hard low-friction resin plate 11c, so that the upper surfaces of the coating layers 11g are flush with the surface of the hard low-friction resin plate 11c.
- the coating layers 11g prevent corrosive substances from contacting the upper surfaces of the small flat-head screws 11d, and prevent magnetic substances contained in the waste 9 from adhering thereto.
- An upper arm 11i has one end fixed to a shaft end of the upper supporting shaft 11p that supports the upper supporting arm 11h, the shaft end protruding from the vertical chute 6.
- An expansion rod of an upper cylinder 11j has a distal end pivotally attached to a distal end of the upper arm 11i. When the expansion rod of the upper cylinder 11j is expanded and contracted, the upper damper body 11a is rotated by 75° through the upper arm 11i, the upper supporting shaft 11p, and the upper supporting arm 11h.
- the lower damper 12 includes a lower damper body 12a and a lower supporting arm 12h.
- the lower damper body 12a includes a damper substrate 12b made of, for example, a SS member or a SUS member, and a hard low-friction resin plate 12c fixed to the upper surface of the damper substrate 12b.
- the lower supporting arm 12h has one end that is rotatably supported by the lower supporting shaft 12p, and the other end that rotatably supports the lower damper body 12a through a bracket 12e and a coupling pin 12f.
- the hard low-friction resin plate 12c is fixed to the upper surface of the damper substrate 12b by a plurality of small flat-head screws 12d (mechanical fastening means) that are respectively screwed into a plurality of internal threads 12s formed in the damper substrate 12b.
- coating layers 12g each having an inverted cone shape are provided to fill spaces above the upper surfaces of the small flat-head screws 12d housed in inverted-cone-shaped screw-head housing holes in the hard low-friction resin plate 12c, so that the upper surfaces of the coating layers 12g are flush with the surface of the hard low-friction resin plate 12c.
- the coating layers 12g prevent corrosive substances from contacting the upper surfaces of the small flat-head screws 12d, and prevent magnetic substances contained in the waste 9 from adhering thereto.
- a lower arm 12i has one end fixed to a shaft end of the lower supporting shaft 12p that supports the lower supporting arm 12h, the shaft end protruding from the vertical chute 6.
- An expansion rod of a lower cylinder 12j has a distal end pivotally attached to a distal end of the lower arm 12i.
- the expansion rod of the lower cylinder 12j is expanded and contracted, the lower damper body 12a is rotated by 75° through the lower arm 12i, the lower supporting shaft 12p, and the lower supporting arm 12h.
- the upper damper 11 and the lower damper 12 have the same operation mechanisms.
- the hard low-friction resin plate 11c in the upper damper body 11a and the hard low-friction resin plate 12c in the lower damper body 12a each are made of ultra high molecular weight polyethylene resin with an ultra high molecular weight of three millions to eight millions.
- the ultra high molecular weight polyethylene resin has been used.
- PC polycarbonate
- ABS acrylonitrile butadiene styrene
- the material of the hard low-friction resin plate is not limited to particular types of resin as long as the material has good wear resistance, good shock resistance, and good chemical resistance.
- the upper damper 11 and the lower damper 12 are alternately opened and closed such that at least one of the upper damper 11 and the lower damper 12 is closed, in order to inhibit external air from entering the gasifier 20.
- the waste-conveying device 7 houses a screw conveyor 13 that conveys the waste 9 fed through the lower damper 12 toward the gasifier 20.
- the screw conveyor 13 includes a pair of conveyance screws 13a having rotation centers parallel to one another in a horizontal plane.
- a waste disintegrator 14 is provided at the distal side of the screw conveyor 13 at a position not occupied by the screw conveyor 13.
- the waste disintegrator 14 disintegrates the waste 9 pushed by the screw conveyor 13.
- the waste disintegrator 14 in the embodiment is rotary type; however, a configuration of rocking type may be used.
- the operation mode of the waste-feeding apparatus 1 having the above-described configuration will be described below.
- the pusher 3 pushes the waste 9 fed into the waste hopper 2.
- the crusher 4 roughly crushes the pushed waste 9.
- the conveyor 5 lifts the waste 9, which has been roughly crushed by the crusher 4, obliquely upward.
- the waste 9 is dropped and fed onto the upper damper 11 of the vertical chute 6.
- the upper damper 11 When the waste 9 is stacked on the upper surface of the upper damper 11 by a predetermined amount, the upper damper 11 is opened, and then closed after several seconds has elapsed. During this period, the waste 9 stacked on the upper damper 11 by the predetermined amount and the waste 9 lifted obliquely upward by the conveyor 5 are fed onto the upper surface of the lower damper 12.
- the lower damper 12 When several seconds has elapsed after the upper damper 11 is closed, the lower damper 12 is opened and the open state is maintained for several seconds.
- the waste 9 fed onto the lower damper 12 is dropped on the screw conveyor 13, more particularly, on the pair of conveyance screws 13a.
- the waste 9 dropped on the pair of conveyance screws 13a is conveyed by rotation of the pair of conveyance screws 13a.
- the waste disintegrator 14 disintegrates the waste 9 discharged from the distal end of the screw conveyor 13 into smaller pieces.
- the waste 9 is fed into the gasifier 20 through the waste-feeding chute 8 and then through the waste inlet 21.
- the waste 9 fed into the gasifier 20 is gasified at temperatures from 500°C to 600°C, and decomposed into combustible gas, fixed carbon, and ash.
- the decomposed combustible gas and fixed carbon are burned in a melting furnace (not shown).
- the ash is molten at temperatures of 1300°C or higher, and becomes molten slag.
- the lower damper 12 is closed when several seconds has elapsed after the waste 9 is fed to the screw conveyor 13.
- the upper damper 11, which has been previously closed is opened. In this way, the upper damper 11 and the lower damper 12 are alternately opened and closed at an interval of predetermined seconds.
- the upper surfaces of the upper damper body 11a and the lower damper body 12a are formed of the hard low-friction resin plates. Even when a sealing surface (not shown) formed on the vertical chute 6 is made of metal, a spark does not occur due to an impact exerted when either damper is closed. Thus, oil contained in the waste 9 is not ignited with the spark. Also, magnetized waste does not adhere to either damper. This can prevent the phenomenon from occurring, the phenomenon in which the magnetized waste adheres to the damper, another magnetized waste is hooked to the adhering magnetized waste, resulting in the waste being accumulated, and hence the waste cannot be smoothly fed into the gasifier. Further, the damper has a low friction coefficient. Thus, the sealing performance is not deteriorated.
- FIG. 5 is an explanatory view schematically showing the configuration of a pressure generator and a control device that controls the pressure generator, the pressure generator operating upper and lower cylinders of upper and lower dampers in a waste-feeding apparatus according to the further comparative example.
- the waste-feeding apparatus according to the further comparative example not part of the invention has the same configuration as the embodiment of the invention. The configuration of the waste-feeding apparatus will be described with reference to Fig. 3 .
- Reference numeral 1 shown in Fig. 3 denotes the waste-feeding apparatus according to an embodiment of the present invention, which implements a waste-feeding method part of the invention.
- the waste-feeding apparatus 1 includes a vertical chute 6 (described below), a waste-conveying device 7 to which waste 9 is fed from the vertical chute 6, and a waste-feeding chute 8 connected with the waste-conveying device 7.
- the waste-feeding chute 8 obliquely extends and communicates with a waste inlet 21 in a gasifier 20, to feed the waste 9.
- a waste-dumping device such as a crane feeds the waste 9 into a waste hopper 2.
- a pusher 3 pushes the waste 9.
- a crusher 4 roughly crushes the pushed waste 9.
- waste primary feeding means includes the waste hopper 2, the pusher 3, the crusher 4, and the conveyor 5.
- the vertical chute 6 includes double dampers having a sealing function, which will be described later.
- the double dampers each have a rectangular cross section.
- the waste-conveying device 7 is connected with the lower end of the vertical chute 6.
- the waste-conveying device 7 includes a screw conveyor and a waste disintegrator, which will be described later.
- the screw conveyor conveys the waste 9 toward the gasifier 20.
- the waste-feeding chute 8 extends obliquely downward and communicates with the waste inlet 21 of the gasifier 20.
- the double dampers provided in the vertical chute 6 include an upper damper 11 and a lower damper 12.
- the lower damper 12 is provided below the upper damper 11 and separated from the upper damper 11 by a predetermined distance.
- An upper supporting shaft 11p is provided on the inner wall of the vertical chute 6 at a position close to the gasifier 20.
- the upper damper 11 is rotated downward by 75° around the upper supporting shaft 11p as a pivot from a closed position inclined at 15° to a horizontal line.
- the upper damper 11 is opened to a vertical position at which the upper damper 11 is orthogonal to the horizontal line.
- the lower damper 12 is provided in the vertical chute 6 at the position below the upper damper 11 and separated from the upper damper 11 of the vertical chute 6 by a predetermined distance.
- a lower supporting shaft 12p is provided on the inner wall of the vertical chute 6 at a position close to the gasifier 20.
- the lower damper 12 is rotated downward by 75° around the lower supporting shaft 12p as a pivot from a closed position inclined at 15° to a horizontal line.
- the lower damper 12 is opened to a vertical position at which the lower damper 12 is orthogonal to the horizontal line.
- the upper supporting shaft 11p and the lower supporting shaft 12p are provided on the inner wall of the vertical chute 6 at the positions close to the gasifier 20 (at the right side in Figs. 3 and 5 ).
- the upper supporting shaft 11p and the lower supporting shaft 12p are provided on the inner wall of the vertical chute 6 at positions far from the gasifier 20 (at the left side in Figs. 3 and 5 ).
- the upper damper 11 and the lower damper 12 are inclined by 15° to the horizontal line in the closed state.
- the inclination angle of the upper and lower dampers 11 and 12 to the horizontal line does not have to be 15° and may be properly determined.
- the upper damper 11 and the lower damper 12 are opened and closed by upper and lower cylinders 11j and 12j that are operated by a pressure generator P U .
- the pressure generator P U feeds or cuts compressed air under the control of a control device C L as shown in Fig. 5 .
- an upper arm 11i has one end fixed to a shaft end of the upper supporting shaft 11p that rotatably supports the upper damper 11, the shaft end protruding from the vertical chute 6.
- An expansion rod of an upper cylinder 11j has a distal end pivotally attached to a distal end of the upper arm 11i.
- the upper damper 11 When the expansion rod of the upper cylinder 11j is expanded and contracted, the upper damper 11 is rotated by 75° through the upper arm 11i and the upper supporting shaft 11p to be opened and closed (the upper damper 11 being closed when the expansion rod is contracted, and opened when the expansion rod is expanded). Also, a limit switch 11sw is provided. The limit switch 11sw contacts the upper arm 11i when the upper arm 11i rotates the upper damper 11 to the closed position. Then, the limit switch 11sw detects that the upper damper 11 is at the closed position, and transmits the detection signal to the control device C L (described below).
- a lower arm 12i has one end fixed to a shaft end of the lower supporting shaft 12p that rotatably supports the lower damper 12, the shaft end protruding from the vertical chute 6.
- An expansion rod of a lower cylinder 12j has a distal end pivotally attached to a distal end of the lower arm 12i.
- the lower damper 12 is rotated by 75° through the lower arm 12i and the lower supporting shaft 12p to be opened and closed (the lower damper 12 being closed when the expansion rod is contracted, and opened when the expansion rod is expanded).
- the upper and lower dampers 11 and 12 have similar damper-operating mechanisms for opening and closing the upper and lower dampers 11 and 12, except for the provision of the limit switch 11sw.
- the expansion rods of the upper and lower cylinders 11j and 12j for opening and closing the upper and lower dampers 11 and 12 are operated with the compressed air fed or cut by the pressure generator P U .
- the pressure generator P U is controlled by the control device C L .
- the control device C L receives an arm-detection signal output from the limit switch 11sw and indicating that the limit switch 11sw has contacted the upper arm 11i. In other words, the control device C L receives a damper-closed signal indicating that the upper damper 11 has been closed.
- control device C L determines that the waste 9 is not caught by the upper damper 11, and controls the pressure generator P U to alternately operate the upper and lower cylinders 11j and 12j in accordance with a normal program.
- control device C L determines that the waste 9 is caught by the upper damper 11, stops the control of the pressure generator P U that normally operates the upper and lower cylinders 11j and 12j in accordance with the aforementioned program.
- the control device C L controls the pressure generator P U as described below, and controls the pusher 3 and the conveyor 5 as described below.
- the determination that the waste 9 is caught by the upper damper 11 is made as follows.
- a timer (not shown) counts the elapsed time since the operation of the upper cylinder 11j has been started to close the upper damper 11 (or since the expansion of the expansion rod has been started). If the damper-closed signal is not output from the limit switch 11sw although a predetermined period (for example, 5 to 10 seconds) has been elapsed, the counting operation is stopped, and it is determined that the waste 9 is caught by the upper damper 11.
- the set period of the timer can be changed depending on the opening and closing speed of the upper damper 11. With this configuration, the unused stop period of the waste-feeding apparatus 1 can be decreased. Thus, the time required for removing the waste 9 caught by the upper damper 11 can be decreased.
- the operation of the pusher 3 and the conveyor 5 is stopped by the control device C L , and hence feeding of the waste 9 to the vertical chute 6 is temporality stopped.
- the pressure generator P U is controlled to operate the upper cylinder 11j.
- the upper damper 11 is opened so that the waste 9 caught by the upper damper 11 is dropped and removed.
- the operation of the pusher 3 and the conveyor 5 is controlled to be started so that feeding of the waste 9 to the vertical chute 6 is started.
- the removal of the waste 9 caught by the upper damper 11 is determined if the damper-closed signal output from the limit switch 11sw is received.
- the upper damper 11 and the lower damper 12 are alternately opened and closed such that at least one of the upper damper 11 and the lower damper 12 is closed, in order to inhibit external air from entering the gasifier 20.
- the waste-conveying device 7 houses a screw conveyor 13 that conveys the waste 9 fed through the lower damper 12 toward the gasifier 20.
- the screw conveyor 13 includes a pair of conveyance screws 13a having rotation centers parallel to one another in a horizontal plane (in Fig. 3 , however, only one of the conveyance screws 13a is shown).
- a waste disintegrator 14 is provided at the distal side of the screw conveyor 13 at a position not occupied by the screw conveyor 13.
- the waste disintegrator 14 disintegrates the waste 9 pushed by the screw conveyor 13.
- the waste disintegrator 14 in the further comparative example is rotary type; however, a configuration of rocking type may be used.
- the operation mode of the waste-feeding apparatus 1 having the above-described configuration for implementing a waste-feeding method will be described below.
- the pusher 3 pushes the waste 9 fed into the waste hopper 2.
- the crusher 4 roughly crushes the pushed waste 9.
- the conveyor 5 lifts the waste 9, which has been roughly crushed by the crusher 4, obliquely upward.
- the waste 9 is dropped and fed onto the upper damper 11 of the vertical chute 6.
- the upper damper 11 When the waste 9 is stacked on the upper damper 11 by a predetermined amount, the upper damper 11 is opened, and then closed after several seconds has elapsed. During this period, the waste 9 stacked on the upper damper 11 by the predetermined amount and the waste 9 lifted obliquely upward by the conveyor 5 are fed onto the lower damper 12.
- the lower damper 12 When several seconds has elapsed after the upper damper 11 is closed, the lower damper 12 is opened and the open state is maintained for several seconds.
- the waste 9 fed onto the lower damper 12 is dropped on the screw conveyor 13, more particularly, on the pair of conveyance screws 13a.
- the waste 9 dropped on the pair of conveyance screws 13a is conveyed by rotation of the pair of conveyance screws 13a.
- the waste disintegrator 14 disintegrates the waste 9 discharged from the distal end of the screw conveyor 13 into smaller pieces.
- the waste 9 is fed into the gasifier 20 through the waste-feeding chute 8 and then through the waste inlet 21.
- the waste 9 fed into the gasifier 20 is gasified at temperatures from 500°C to 600°C, and decomposed into combustible gas, fixed carbon, and ash. Then, the decomposed combustible gas and fixed carbon are burned in a melting furnace (not shown).
- the ash is molten at temperatures of 1300°C or higher, and becomes molten slag.
- the lower damper 12 is closed when several seconds has elapsed after the waste 9 is fed to the screw conveyor 13. Then, the upper damper 11, which has been previously closed, is opened. In this way, the upper damper 11 and the lower damper 12 are repeatedly alternately opened and closed at an interval, for example, from 15 seconds to 3 minutes.
- the interval of the operation for opening and closing each of the upper and lower dampers 11 and 12 is not limited to the above-described interval, and may be properly determined.
- the limit switch 11sw is not operated because the expansion rod does not achieve the minimum stroke (the most contracted state) although the closing operation of the upper damper 11 is selected, in which the expansion rod of the upper cylinder 11j is contracted.
- the damper-closed signal is not transmitted to the control device C L .
- the control device C L outputs an operation stop instruction signal, and hence the operation of the pusher 3 and the conveyor 5 is stopped. Accordingly, feeding of the waste 9 to the vertical chute 6 is temporarily stopped.
- the pressure generator P U switches the operation to the opening operation of the upper damper 11, in which the expansion rod of the upper cylinder 11j is expanded, to open the upper damper 11.
- the waste 9 caught by the upper damper 11 is removed.
- the expansion rod of the upper cylinder 11j is contacted to close the upper damper 11, which has been opened for removal of the caught waste 9.
- the control device C L receives the damper-closed signal, the operation of the pusher 3 and the conveyor 5 is started to start the feeding of the waste 9 to the vertical chute 6. Thereafter, the operation state is recovered to the normal operation state.
- the waste 9 cannot be removed although the upper damper 11 has been opened for the removal of the caught waste 9, and the damper-closed signal cannot be received although the upper damper 11 has been operated to be closed.
- the opening and closing operation for the upper damper 11 is repeated until the damper-closed signal is received.
- the opening and closing operation for the upper damper 11 By repeating the opening and closing operation for the upper damper 11, external air can be reliably inhibited from entering the gasifier 20.
- the operating ratio of the waste-feeding apparatus 1 and the waste-processing amount may be degraded.
- the time required for repeating the opening and closing operation is markedly shorter than the time required for removing the waste 9 by opening an access hole.
- the operating ratio of the waste-feeding apparatus 1 and the waste-processing amount can be less degraded.
- the above-described operation is carried out when the waste 9 is caught by the upper damper 11.
- the control device C L receives the damper-closed signal, and it is determined that the upper damper 11 is completely closed and the waste 9 is not caught by the upper damper 11, the feeding of the waste 9 to the vertical chute 6 is continued, and the operation of the waste primary feeding means located upstream of the vertical chute 6, that is, the operation of the pusher 3 and the conveyor 5 is not stopped.
- FIG. 6 is an explanatory view schematically showing the configuration of a pressure generator and a control device that controls the pressure generator, the pressure generator operating upper and lower cylinders of upper and lower dampers.
- the modified further comparative example has a configuration similar to that of the further comparative example except for the position of a lower supporting shaft that rotatably supports a lower damper.
- the same reference numerals refer components equivalent to those in the further comparative example or components having the same functions as those in the further comparative example.
- the point of the modified further comparative example different from the further comparative example will be mainly described.
- an upper supporting shaft 11p is provided on the inner wall of the vertical chute 6 at a position close to the gasifier 20 (at the right side in Fig. 6 ).
- the upper damper 11 is rotated downward by 75° around the upper supporting shaft 11p as a pivot from a closed position inclined at 15° to a horizontal line.
- the upper damper 11 is opened to a vertical position at which the upper damper 11 is orthogonal to the horizontal line.
- a lower supporting shaft 12p is provided on the inner wall of the vertical chute 6 at a position far from the gasifier 20 (at the left side in Fig. 6 ).
- the lower damper 12 is rotated downward by 75° around the lower supporting shaft 12p as a pivot from a closed position inclined at 15° to a horizontal line.
- the lower damper 12 is opened to a vertical position at which the lower damper 12 is orthogonal to the horizontal line.
- the waste-feeding apparatus according to the modified further comparative example not part of the invention for implementing the waste-feeding method not part of the invention only the position of the lower supporting shaft 12p that rotatably supports the lower damper 12 is different.
- a similar advantage to that of the waste-feeding apparatus according to the further comparative example can be attained.
- the waste 9 is dropped from the upper damper 11 toward the lower supporting shaft 12p of the lower damper 12, slides on the upper surface of the lower damper 12, and is dropped onto the position close to the next process.
- the waste 9 can be prevented from adhering to the upper surface of the lower damper 12, and the waste 9 on the upper surface of the lower damper 12 can be removed by wiping effect of the waste 9 as a result of sliding.
- the interval for cleaning of the lower damper 12 can be increased, the operating cost of the waste-feeding apparatus can be decreased, and the operating ratio can be improved.
- the upper damper 11 is opened and closed when the waste 9 is caught by the upper damper 11, and it is determined that the caught waste 9 has been removed in response to the damper-closed signal from the limit switch 11sw.
- the waste 9 is less frequently caught by the lower damper 12 as compared with the upper damper 11.
- the lower damper 12 may not become completely closed, for example, due to a muddy substance adhering onto the damper surface.
- a limit switch (not shown) is provided.
- the limit switch contacts a lower arm 12i when a lower cylinder 12j makes a minimum stroke, detects that the lower damper 12 is at a closed position, and transmits the detection signal to the control device C L . If the control device C L does not receive the damper-closed signal from the limit switch although the lower cylinder 12j, which opens and closes the lower damper 12, has been operated to close the lower damper 12 and a predetermined time counted by a timer has been elapsed, it is determined that the waste 9 is caught by the lower damper 12. The lower damper 12 is opened to remove the caught waste 9, and then the open lower damper 12 is closed.
- the control device C L After the operation, if the control device C L receives the damper-closed signal from the limit switch, it is determined that the waste 9 caught by the lower damper 12 is removed. The upper damper 11 is opened, so that the waste 9 stacked on the upper damper 11 is dropped and fed onto the lower damper 12.
- the waste-feeding method according to further modified further comparative example in addition to the advantages of the waste-feeding method according to further comparative example and modified further comparative example, it can be recognized that the waste 9 is caught by the lower damper 12. Also, the waste 9 caught by the lower damper 12 can be reliably removed. Thus, the waste 9 is not accumulated or stayed on the lower damper 12 as a result of the waste 9 being caught by the lower damper 12.
- the waste 9 can be reliably conveyed by the waste-conveying device 7 and fed into the waste inlet 21, the volumetric feeding performance for the waste 9 is hardly deteriorated, and the processing efficiency for the waste 9 can be increased. Also, the unused stop period of the waste-feeding apparatus can be decreased. Thus, the time required for removing the waste 9 caught by the lower damper 12 can be decreased. Since at least two limit switches are required, the configuration of the control system for controlling damper operating means does not become complicated or expensive.
- the upper and lower dampers are closed when the upper and lower cylinders are contracted, and the upper and lower dampers are opened when the upper and lower dampers are expanded.
- the upper and lower dampers may be closed when the upper and lower cylinders are expanded, and the upper and lower dampers may be opened when the upper and lower cylinders are contacted (for example, the directions of the arms may be opposite to the directions shown in Figs. 5 and 6 , or if the directions of the arms are the same as the directions shown in Figs. 5 and 6 , the upper and lower cylinders may be configured such that the expansion rods are expanded downward).
- the waste-feeding apparatus according to any of the above-described embodiments part of the invention and comparative examples not part of the invention, and the waste-feeding apparatus according to any of the above-described embodiments for implementing the waste-feeding methods of the present invention and comparative examples not part of the invention for implementing the waste-feeding methods not part of the invention, are merely examples of the present invention, and the design thereof can be feely changed within the technical scope of the present invention. Therefore, the configuration of the waste-feeding apparatus is not limited to the configuration of the waste-feeding apparatus 1 according to any of the above-described embodiments and comparative examples.
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- Processing Of Solid Wastes (AREA)
Description
- The present invention relates to a waste-feeding apparatus according to the preamble of
claim 1 and a sealing method according to the preamble ofclaim 4 for preventing a spark from occurring when double dampers having a sealing function that inhibits external air from entering a gasifier are closed and for preventing magnetized waste or fine waste from adhering to the dampers. - Recently, a gasification and melting furnace has been popular, which can reduce the volume of waste, such as sludge and municipal waste, and render the ash of the waste harmless. The gasification and melting furnace gasifies the waste, such as sludge and municipal waste, in a gasifier (at temperatures from 500°C to 600°C), and decomposes the waste into combustible gas, fixed carbon, and ash. The decomposed combustible gas and fixed carbon are burned in a melting furnace. The temperature in the melting furnace is increased to 1300°C or higher to melt the ash. In addition, molten slag is cooled, for example, with water to produce water-cooled slag.
- A waste-feeding apparatus that feeds waste to a gasifier requires volumetric feeding performance of the waste, and sealing performance.
- By reducing the variation in feeding amount of waste as much as possible, combustion is stabilized. Accordingly, the temperature in the melting furnace becomes stable, and the fusibility of ash becomes stable.
- External air is inhibited from entering the gasifier and combustible gas (CO, H, CH4, etc.) is inhibited from leaking out the gasifier.
- For example, a waste-feeding apparatus for a gasifier having double dampers in a chute has been known.
- A waste-feeding apparatus (a combustible-substance-feeding apparatus) for a gasifier according to related art will be described below with reference to the attached drawing.
Fig. 7 illustrates the general configurations of a fluidized-bed gasifier and a combustible-substance-feeding apparatus (hereinafter, referred to as a waste-feeding apparatus) that feeds a combustible substance (hereinafter, referred to as waste) to the fluidized-bed gasifier, according to related art. Referring toFig. 7 , a fluidized-bed gasifier (hereinafter, referred to as gasifier) 50 includes a waste-feeding mechanism 62 at awaste inlet 53 in thegasifier 50, achute 63 connected with the waste-feeding mechanism 62, and aconveyor 65 connected with thechute 63. The waste-feeding mechanism 62 includes ascrew conveyor 64 that is driven by amotor 68. Thechute 63 includesdouble dampers 59. -
Waste 54 fed into ahopper 66 by acrane 61 or the like is lifted through theconveyor 65, and fed into an upper opening of thechute 63 from the distal end of theconveyor 65. Thewaste 54 fed into thechute 63 is intermittently fed into the waste-feeding mechanism 62 by the operation of thedouble dampers 59 having a sealing function. Thescrew conveyor 64 in the waste-feeding mechanism 62 reduces the intermittency of the intermittently fedwaste 54 and allows thewaste 54 to be fed into thegasifier 50 continuously by a predetermined constant amount (in a volumetric manner). - The
waste 54 fed into thegasifier 50 is gasified in a reducing atmosphere in a fluidizedbed 51 being fluidized with fluidizinggas 52 blown from a wind box at the bottom. Producedgas 57 produced through the gasification exits from the fluidizedbed 51, passes through afreeboard 55, and is guided to a melting furnace (not shown) through a produced-gas outlet 56. In this case, thewaste 54, which has been intermittently fed from thechute 63, is continuously fed by a substantially constant amount (in a volumetric manner) by the effect of thescrew conveyor 64 in the waste-feeding mechanism 62. Thus, control for stable gasification operation of thegasifier 50, such as control for feeding the fluidizinggas 52 and control for the temperature in the furnace, is easily carried out. In addition, the sealing function of thedouble dampers 59 can inhibit external air from leaking into thegasifier 50 through thewaste inlet 5 Prior artJP 2003 056822 claim 1 and a sealing method of a waste feeding apparatus. - Since the waste-
feeding mechanism 62 for thegasifier 50 according to the related art includes the double dampers having an upper damper and a lower damper, which are alternately opened and closed, in thechute 63, the waste-feeding mechanism 62 has good sealing performance. Also, since the waste-feeding mechanism 62 includes thescrew conveyor 64, the waste-feeding mechanism 62 has good volumetric feeding performance for thewaste 54 to thegasifier 50. However, the waste-feeding mechanism 62 for thegasifier 50 according to the related art does not have sufficient volumetric feeding performance for thewaste 54. - (1) A supporting shaft that supports the lower damper in an openable and closable manner is provided on the inner wall of the chute at a position close to the
gasifier 50. Owing to this, thewaste 54 is fed to a position on thescrew conveyor 64 in the waste-feeding mechanism 62 farthest from thegasifier 50. The waste takes a time to reach thewaste inlet 53 of thegasifier 50. There may be the period during which a small amount of thewaste 54 is provided on thescrew conveyor 64. Consequently, the feeding amount of thewaste 54 to thegasifier 50 may vary. - (2) When the
screw conveyor 64 in the waste-feeding mechanism 62 includes a pair of conveyance screws having rotation centers parallel to one another in a horizontal plane, thewaste 54 may be unevenly distributed in the width direction and the longitudinal direction of thescrew conveyor 64. In particular, the volume of thewaste 54 may be increased at the left side or the right side in a range in the longitudinal direction of thescrew conveyor 64. The feeding amount of thewaste 54 to thegasifier 50 may vary. - As described above, the waste-feeding apparatus for the gasifier according to the related art has the good sealing performance and good volumetric feeding performance for the waste to the gasifier. Meanwhile, a damper is typically made of a SS member or a SUS member having good resistance to corrosion. When the chute is made of metal, a spark may occur due to an impact exerted when the damper is closed. For example, oil contained in the waste may be ignited with the spark.
- Also, when the damper is made of the SS member, magnetized waste may adhere to the damper, and another magnetized waste may be hooked to the adhering magnetized waste, resulting in the waste being accumulated. It is difficult to smoothly feed the waste to the gasifier. Further, when the damper is made of metal, the metal damper has a high friction coefficient. Hence, wet fine waste may adhere to the damper. The sealing performance may be deteriorated.
- As described above, the waste-feeding apparatus for the gasifier according to the related art has the good sealing performance and good volumetric feeding performance for the waste to the gasifier. However, when the waste is caught by the damper, the sealing performance cannot be maintained. Thus, it is difficult to inhibit external air from entering the gasifier. When the waste is caught by the damper, the operation of the waste-feeding apparatus has to be stopped, and the waste caught by the damper has to be removed through, for example, an access hole provided in the chute. This may decrease the operating ratio of the waste-feeding apparatus, and a troublesome work is needed for removing the waste. Thus, in the case of the waste-feeding apparatus for the gasifier according to the related art, the following operation is carried out to prevent the waste from being caught by the damper.
- When the open damper is closed, the operation of upstream equipment for feeding the waste to the chute provided with the damper is temporarily stopped. After it is checked that the damper has been completely closed, the upstream equipment is operated. When the waste-feeding apparatus is operated in this manner, the following problems may occur.
- (1) Since the operation of the upstream equipment, that is, waste primary feeding means is more frequently started and stopped, the life of the waste primary feeding means may be decreased, and hence the operating cost may be increased.
- (2) The volumetric feeding performance of the waste is deteriorated, the processing efficiency of the waste is decreased, and the variation in the amount of produced gas, which is gasified in the gasifier, is increased. Thus, it is difficult to carry out the control for stable gasification operation of the gasifier and the control for stable operation of the melting furnace located downstream of the gasifier.
- The object of the present invention is to further improve a waste-feeding apparatus according to the preamble of
claim 1 and a sealing method according to the preamble ofclaim 4 so as to prevent a spark from occurring when double dampers having a sealing function that inhibits external air from entering a gasifier are closed and so as to prevent magnetized waste or fine waste from adhering to the dampers. The object is achieved by a waste-feeding apparatus having the features ofclaim 1 and by a sealing method having the features ofclaim 4. - Advantageous further developments of the invention are set out in the dependent claims.
- To attain the object, a waste-feeding apparatus according to the present invention is provided. The waste-feeding apparatus includes a vertical chute and a waste-conveying device. The vertical chute includes upper and lower dampers separated from one another by a predetermined distance in an up-down direction, the upper and lower dampers having a sealing function that inhibits external air from entering a gasifier and configured to be alternately opened and closed. The waste-conveying device is configured to convey waste, which has been fed through the vertical chute, toward the gasifier. The upper and lower dampers have damper bodies, each of the damper bodies having a damper substrate and a hard low-friction resin plate fixed to an upper surface of the damper substrate by mechanical fastening means. When the upper or lower damper is closed, an upper surface of an outer edge portion of the hard low-friction resin plate contacts a sealing surface formed on an inner side of the vertical chute.
- Preferably, the mechanical fastening means may be a small flat-head screw that is screwed into an internal thread formed in the damper substrate such that an upper surface of a screw head is lower than an upper surface of the hard low-friction resin plate. A resin coating layer may be formed on the upper surface of the screw head.
- A sealing method of a waste-feeding apparatus for inhibiting external air from entering a gasifier according to the present invention is provided. The waste-feeding apparatus includes a vertical chute and a waste-conveying device. The vertical chute includes upper and lower dampers separated from one another by a predetermined distance in an up-down direction. The waste-conveying device is configured to convey waste, which has been fed through the vertical chute, toward the gasifier. The sealing method includes the step of, when the upper and lower dampers are alternately closed for sealing, bringing an upper surface of an outer edge portion of a hard low-friction resin plate of a damper body in each of the upper and lower dampers into contact with a sealing surface formed on an inner side of the vertical chute.
- The inventors have learned that, if the upper and lower dampers are opened and closed at an interval of, for example, 15 seconds, each damper is opened and closed 240 times per hour, however, the number of times the waste is caught by the upper damper per hour is no more than two (1/120). The inventors have assumed that the aforementioned problems (1) and (2), described in Description of the Related Art, can be markedly improved if the unnecessary starting and stopping of the upstream devices by 238 times are omitted. Thus, the inventors have implemented the waste-feeding method according to a comparative example not part of the invention. The phenomenon that the number of times the waste is caught by the upper damper per hour is not more than two can be attained by the following reasons. A block of waste roughly crushed by a crusher is dropped and fed onto the upper damper at a certain individual interval, and hence the block of waste is less frequently dropped at a predetermined position simultaneously when the upper damper is closed. Also, as the apparatus is operated for a long term, a muddy substance may adhere onto the lower damper.
- In the waste-feeding apparatus according to the comparative example not part of the invention, the lower damper includes the lower left damper and the lower right damper configured to be opened and closed through the supporting shafts. The supporting shafts are provided on the opposite portions of the inner wall of the vertical chute and parallel to the center line. The center line extends in the longitudinal direction and passing through the center in the width direction of the waste-conveying device. The merged line defined by the distal portions of the lower left damper and the lower right damper in the closed state is located above the center line. Also, the waste-feeding method according to the comparative example not part of the invention includes the steps of, after the upper damper is closed, opening the lower damper around the supporting shafts as the pivots, the supporting shafts being provided on the opposite portions of the inner wall of the vertical chute and parallel to the center line, the center line extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device; and dropping the waste, which has been received while the upper damper is opened, toward the center line to convey the waste by the waste-conveying device.
- With the waste-feeding apparatus according to the comparative example not part of the invention and with the waste-feeding method according to the comparative example not part of the invention, the waste having the length corresponding to the length of the lower damper in a direction toward the gasifier is fed to the waste-conveying device. Also, the waste is dropped at the center in the width direction of the waste-conveying device immediately after the lower left damper and the lower right damper start to be opened. Then, as the opening becomes larger, the area in which the waste is dropped becomes larger in a direction away from the center in the width direction. Thus, the waste on the waste-conveying device has a cross section in a mound-like shape at any position in the longitudinal direction toward the gasifier. The variation in volume of the waste in the left-right direction can be reduced. The volumetric feeding performance of the waste to the gasifier is improved.
- In the waste-feeding apparatus according to the comparative example not part of the invention, the lower left damper and the lower right damper of the lower damper may be lowered toward the distal portions from the supporting shafts in the closed state. With the waste-feeding apparatus according to the comparative example not part of the invention, the upper surfaces of the lower left damper and the lower right damper are inclined in the closed state, and hence have a hopper-like shape. The waste can be efficiently fed onto the waste-conveying device when the lower left damper and the lower right damper start to be opened.
- In the waste-feeding apparatus according to the comparative example not part of the invention, the waste-conveying device may be the screw conveyor including the pair of conveyance screws having the rotation centers parallel to one another in the horizontal plane. With the waste-feeding apparatus according to the comparative example not part of the invention, the waste having the length corresponding to the length of the lower damper in a direction toward the gasifier is fed from the lower damper to an area between the pair of conveyance screws of the screw conveyor.
- In the waste-feeding apparatus according to the comparative example not part of the invention, the waste disintegrator may be provided at the forward position of the distal end of the screw conveyor, the waste disintegrator configured to disintegrate the waste conveyed by the screw conveyor.
- Also, the waste-feeding method according to the comparative example not part of the invention may further include the step of feeding the waste, which has been conveyed by the waste-conveying device, into the gasifier while disintegrating the waste by the waste disintegrator.
- With the waste-feeding apparatus according to the comparative example not part of the invention and with the waste-feeding method according to the comparative example not part of the invention, since the waste disintegrator disintegrates the waste, which has been conveyed by the screw conveyor or the waste-conveying device, the volumetric feeding performance of the waste can be further improved.
- In the waste-feeding apparatus according to the present invention and in the sealing method according to the present invention, the upper surface of the outer edge portion of the hard low-friction resin plate on the damper body in each of the upper and lower dampers provided in the vertical chute of the waste-feeding apparatus contacts the sealing surface formed on the inner side of the vertical chute.
- With the waste-feeding apparatus according to the present invention and with the sealing method according to the present invention, when the upper or lower damper is closed, the upper surface of the outer edge portion of the hard low-friction resin plate contacts the sealing surface formed on the inner side of the vertical chute. Accordingly, even when the sealing surface formed on the vertical chute is made of metal, a spark does not occur. Further, magnetized waste does not adhere to the hard low-friction resin plate. Also, since the hard low-friction resin plate has a low friction coefficient, wet fine waste does not adhere to the hard low-friction resin plate. Hence, the sealing performance is not deteriorated.
- Preferably, the hard low-friction resin plate may be attached to the damper substrate by the small flat-head screw (the mechanical fastening means). Accordingly, the hard low-friction resin plate can be easily attached to and detached from (replaced in) the damper substrate. Also, the resin coating layer may be formed on the upper surface of the screw head of the small flat-head screw. Accordingly, magnetic substances can be prevented from adhering to the screw head of the small flat-head screw, and corrosive substances can be prevented from contacting the screw head.
- The waste-feeding method according to the further comparative example not part of the invention includes the steps of, if the damper-closed signal is not received although the upper cylinder, which opens and closes the upper damper, has been operated to close the upper damper, determining that the waste is caught by the upper damper, and temporarily stopping feeding of the waste to the vertical chute; during the stop of the feeding of the waste, opening the upper damper to remove the caught waste, and closing the open upper damper; and if the damper-closed signal is received, determining that the waste caught by the upper damper has been removed, and starting the feeding of the waste to the vertical chute.
- With the waste-feeding method according to the further comparative example not part of the invention, if the waste is not caught by the upper damper, the feeding of the waste to the vertical chute is continued, and the operation of waste primary feeding means located upstream of the vertical chute is not stopped. The following advantages can be attained.
- (1) Since the operation of the waste primary feeding means at the upstream side is less frequently started and stopped, the life of the waste primary feeding means is not decreased, and hence, the operating cost can be decreased.
- (2) The volumetric feeding performance of the waste is hardly deteriorated, the processing efficiency of the waste is increased, and the variation in the amount of produced gas, which is gasified in the gasifier, can be decreased. Thus, it is easy to carry out the control for stable gasification operation of the gasifier and the control for stable operation of the melting furnace located downstream of the gasifier.
- The waste-feeding method according to the further comparative example not part of the invention may further include the steps of starting counting an elapsed time by a timer since the operation of the upper cylinder to close the upper damper has started; and if the damper-closed signal is not output although a predetermined period has elapsed, stopping the counting, and determining that the waste is being caught by the upper damper. Thus, with the waste-feeding method according to the further comparative example not part of the invention, the unused stop period of the waste-feeding apparatus can be decreased. Thus, the time required for removing the waste caught by the upper damper can be decreased.
- In the waste-feeding method according to the further comparative example not part of the invention, the damper-closed signal of the upper damper may be output from the limit switch that detects the stroke of the upper cylinder. With the waste-feeding method according to the further comparative example not part of the invention, at least one limit switch is required. The configuration of the control system for controlling damper operating means does not become complicated or expensive.
- The waste-feeding method according to the further comparative example not part of the invention, may further include the steps of, if the damper-closed signal is not received although a lower cylinder, which opens and closes the lower damper, has been operated to close the lower damper, determining that the waste is caught by the lower damper, opening the lower damper to remove the caught waste, and closing the lower damper; and if the damper-closed signal is received, determining that the waste, which has been caught by the lower damper, is removed, and opening the upper damper.
- With the waste-feeding method according to further comparative example not part of the invention, in addition to the advantages of the above waste-feeding method, it can be recognized that the waste is caught by the lower damper. Also, the waste caught by the lower damper can be reliably removed. The waste is not accumulated and stayed on the lower damper as a result of the waste being caught by the lower damper, and the waste can be reliably conveyed by the waste-conveying device and fed into the waste inlet. Accordingly, the volumetric feeding performance for the waste is hardly deteriorated, and the processing efficiency for the waste can be increased.
- The waste-feeding method according to the further comparative example not part of the invention may further include the steps of starting counting an elapsed time by a timer since the operation of the lower cylinder to close the lower damper has started; and if the damper-closed signal is not output although a predetermined period has elapsed, stopping the counting, and determining that the waste is being caught by the lower damper. Thus, with the waste-feeding method according to the further comparative example not part of the invention, the unused stop period of the waste-feeding apparatus can be decreased. Thus, the time required for removing the waste caught by the lower damper can be decreased.
- In the waste-feeding method according to the further comparative example not part of the invention, the damper-closed signal of the lower damper may be output from the limit switch that detects the stroke of the lower cylinder. With the waste-feeding method according to the further comparative example not part of the invention, at least two limit switches are required. The configuration of the control system for controlling damper operating means does not become complicated or expensive.
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Fig. 1 is an explanatory view schematically showing the configuration of a waste-feeding apparatus for a gasifier according to the comparative example not part of the invention; -
Fig. 2A is a cross-sectional view taken along line A-A inFig. 1 ,Fig. 2A being an explanatory view showing the open and closed states of upper and lower dampers and showing the shape of waste fed by a pair of conveyance screws of a screw conveyor (a waste-conveying device); -
Fig. 2B is a cross-sectional view taken along line B-B inFig. 1 ,Fig. 2B being an explanatory view showing the plan state of the waste conveyed by the pair of conveyance screws of the screw conveyor; -
Fig. 3 is an explanatory view schematically showing the configuration of a waste-feeding apparatus according to an embodiment of the present invention,Fig. 3 also showing a gasifier for gasification of the waste; -
Fig. 4A is an explanatory view schematically showing the configurations of upper and lower dampers according to an embodiment of the present invention; -
Fig. 4B is an enlarged cross-sectional view showing part C inFig. 4A ; -
Fig. 5 is an explanatory view schematically showing the configuration of a pressure generator and a control device that controls the pressure generator, the pressure generator operating upper and lower cylinders of upper and lower dampers in a waste-feeding apparatus according to the further comparative example not part of the invention; -
Fig. 6 is an explanatory view schematically showing the configuration of a pressure generator and a control device that controls the pressure generator, the pressure generator operating upper and lower cylinders of upper and lower dampers in a waste-feeding apparatus according to the modified further comparative example not part of the invention; and -
Fig. 7 illustrates the general configurations of a fluidized-bed gasifier and a waste-feeding apparatus that feeds waste to the fluidized-bed gasifier, according to related art. - A waste-feeding apparatus according to the comparative example not part of the invention will be described below with reference to the attached drawings.
Fig. 1 is an explanatory view schematically showing the configuration of a waste-feeding apparatus according to the comparative example.Fig. 2A is a cross-sectional view taken along line A-A inFig. 1 ,Fig. 2 being an explanatory view showing the open and closed conditions of upper and lower dampers and showing the shape of waste fed by a pair of conveyance screws of a screw conveyor (a waste-conveying device).Fig. 2B is a cross-sectional view taken along line B-B inFig. 1 ,Fig. 2B being an explanatory view showing the plan state of the waste conveyed by the pair of conveyance screws of the screw conveyor. -
Reference numeral 1 shown inFig. 1 denotes the waste-feeding apparatus according to the comparative example. The waste-feedingapparatus 1 includes a vertical chute 6 (described below), a waste-conveyingdevice 7 to whichwaste 9 is fed from thevertical chute 6, and a waste-feedingchute 8 connected with the waste-conveyingdevice 7. The waste-feedingchute 8 obliquely extends and communicates with awaste inlet 21 in agasifier 20, to feed thewaste 9. To be more specific, a waste-dumping device (not shown) such as a crane feeds thewaste 9 into awaste hopper 2. Apusher 3 pushes thewaste 9. Acrusher 4 roughly crushes the pushedwaste 9. Then, aconveyor 5 provided in an air-tight conveyor housing lifts thewaste 9, which has been roughly crushed by thecrusher 4, obliquely upward. Thewaste 9 is dropped and fed into thevertical chute 6. - The
vertical chute 6 includes double dampers having a sealing function, which will be described later. The double dampers each have a rectangular cross section. The waste-conveyingdevice 7 is connected with the lower end of thevertical chute 6. The waste-conveyingdevice 7 includes a screw conveyor and a waste disintegrator, which will be described later. The screw conveyor conveys thewaste 9 toward thegasifier 20. The upper end of the waste-feedingchute 8 is connected with the lower distal end of the waste-conveyingdevice 7. The waste-feedingchute 8 extends obliquely downward and communicates with thewaste inlet 21 of thegasifier 20. - The double dampers provided in the
vertical chute 6 include anupper damper 11 and alower damper 12. Thelower damper 12 is provided below theupper damper 11 and separated from theupper damper 11 by a predetermined distance. The upper andlower dampers Fig. 2 . The configuration of theupper damper 11 will be described first. Theupper damper 11 includes an upperleft damper 11L and an upperright damper 11R. The upperleft damper 11L is opened and closed through an upper supportingshaft 11p. The upper supportingshaft 11p is parallel to a center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveyingdevice 7. The upper supportingshaft 11p is provided on a left portion of the inner wall of thevertical chute 6 in a view facing thegasifier 20. The upperright damper 11R is opened and closed through an upper supportingshaft 11p. The upper supportingshaft 11p is parallel to the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveyingdevice 7. The upper supportingshaft 11p is provided on a right portion of the inner wall of thevertical chute 6 in a view facing thegasifier 20. - A
merged line 11m is defined when the upperleft damper 11L and the upperright damper 11R are closed and distal portions of the upperleft damper 11L and the upperright damper 11R contact one another, the distal portions being straight and facing one another. Themerged line 11m is located at the center in the left-right direction of thevertical chute 6, that is, at a position above the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveyingdevice 7. In a state in which the upperleft damper 11L and the upperright damper 11R are closed, the upperleft damper 11L and the upperright damper 11R are lowered toward the distal portions from the upper supportingshafts 11p. In particular, in that state, the upperleft damper 11L and the upperright damper 11R define an angle θ of, for example, 150°. - In the comparative example, the
upper damper 11 has the two dampers including the upperleft damper 11L and the upperright damper 11R. However, similar to the damper in the related art, theupper damper 11 may have a single damper and may be opened and closed through an upper supporting shaft provided on the inner wall of thevertical chute 6 at a position close to thegasifier 20. - The configuration of the
lower damper 12 will be described next. Thelower damper 12 includes a lowerleft damper 12L and a lowerright damper 12R. The lowerleft damper 12L is opened and closed through a lower supportingshaft 12p. The lower supportingshaft 12p is parallel to the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveyingdevice 7. The lower supportingshaft 12p is provided on a left portion of the inner wall of thevertical chute 6 in a view facing thegasifier 20. The lowerright damper 12R is opened and closed through a lower supportingshaft 12p. The lower supportingshaft 12p is parallel to the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveyingdevice 7. The lower supportingshaft 12p is provided on a right portion of the inner wall of thevertical chute 6 in a view facing thegasifier 20. - A
merged line 12m is defined when the lowerleft damper 12L and the lowerright damper 12R are closed and distal portions of the lowerleft damper 12L and the lowerright damper 12R contact one another, the distal portions being straight and facing one another. Themerged line 12m is located at the center in the left-right direction of thevertical chute 6, namely, at a position above the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveyingdevice 7. In a state in which the lowerleft damper 12L and the lowerright damper 12R are closed, the lowerleft damper 12L and the lowerright damper 12R are lowered toward the distal portions from the lower supportingshafts 12p. In particular, in that state, the lowerleft damper 12L and the lowerright damper 12R define an angle θ of, for example, 150°. - With the
lower damper 12, the upper surfaces of the lowerleft damper 12L and the lowerright damper 12R are inclined in the closed state, and hence have a hopper-like shape. Thewaste 9 can be efficiently fed onto the screw conveyor (described below) when the lowerleft damper 12L and the lowerright damper 12R start to be opened. - The
upper damper 11 and thelower damper 12 are alternately opened and closed such that at least one of theupper damper 11 and thelower damper 12 is closed, in order to inhibit external air from entering thegasifier 20. - The waste-conveying
device 7 houses ascrew conveyor 13 that conveys thewaste 9 fed through thelower damper 12 toward thegasifier 20. Thescrew conveyor 13 includes a pair ofconveyance screws 13a having rotation centers parallel to one another in a horizontal plane. In addition, awaste disintegrator 14 is provided at the distal side of thescrew conveyor 13 at a position not occupied by thescrew conveyor 13. Thewaste disintegrator 14 disintegrates thewaste 9 pushed by thescrew conveyor 13. - The
waste disintegrator 14 in the comparative example is rotary type; however, a configuration of rocking type may be used. - The operation mode of the waste-feeding
apparatus 1 having the above-described configuration will be described below. Thepusher 3 pushes thewaste 9 fed into thewaste hopper 2. Thecrusher 4 roughly crushes the pushedwaste 9. Theconveyor 5 lifts thewaste 9, which has been roughly crushed by thecrusher 4, obliquely upward. Thewaste 9 is dropped and fed onto theupper damper 11 of thevertical chute 6. - When the
waste 9 is stacked on theupper damper 11 by a predetermined amount, theupper damper 11 is opened, and then closed after several seconds has elapsed. During this period, thewaste 9 stacked on theupper damper 11 by the predetermined amount and thewaste 9 lifted obliquely upward by theconveyor 5 are fed onto the upper surface of thelower damper 12. When several seconds has elapsed after theupper damper 11 is closed, thelower damper 12 is opened and the open state is maintained for several seconds. When thewaste 9 fed onto thelower damper 12 is fed to thescrew conveyor 13, the distal portions of the lowerleft damper 12L and the lowerright damper 12R are opened, the distal portions being straight and facing one another. Thus, thewaste 9 is dropped on the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveyingdevice 7. In particular, thewaste 9 is dropped in an area between the pair ofconveyance screws 13a of thescrew conveyor 13. - Accordingly, the
waste 9 having the length corresponding to the length of thelower damper 12 in a direction toward thegasifier 20 is fed to the pair ofconveyance screws 13a of thescrew conveyor 13. Also, thewaste 9 is stacked in a mound-like shape in the width direction of the pair ofconveyance screws 13a of thescrew conveyor 13. The variation in volume of thewaste 9 in the left-right direction can be reduced. Thewaste 9 fed to thescrew conveyor 13 is conveyed by rotation of the pair ofconveyance screws 13a. Thewaste disintegrator 14 disintegrates thewaste 9 into smaller pieces. Thewaste 9 is fed into thegasifier 20 through the waste-feedingchute 8 and then through thewaste inlet 21. Thewaste 9 fed into thegasifier 20 is gasified at temperatures from 500°C to 600°C, and decomposed into combustible gas, fixed carbon, and ash. Then, the decomposed combustible gas and fixed carbon are burned in a melting furnace (not shown). The ash is molten at temperatures of 1300°C or higher, and becomes molten slag. Thelower damper 12 is closed when several seconds has elapsed after thewaste 9 is fed to thescrew conveyor 13. Then, theupper damper 11, which has been previously closed, is opened. In this way, theupper damper 11 and thelower damper 12 are alternately opened and closed at an interval of predetermined seconds. - In the waste-feeding
apparatus 1 according to the comparative example, as described above, thelower damper 12 includes the lowerleft damper 12L and the lowerright damper 12R. The lowerleft damper 12L and the lowerright damper 12R are provided on the opposite portions of the inner wall of thevertical chute 6 and opened and closed through the lower supportingshafts 12p. Thelower supporting shafts 12p are parallel to the center line Lc. The center line Lc extends in the longitudinal direction and passes through the center in the width direction of the waste-conveyingdevice 7. Themerged line 12m defined by the distal portions of the lowerleft damper 12L and the lowerright damper 12R in the closed state is located above the center line Lc. - Accordingly, with the waste-feeding
apparatus 1 according to the comparative example, thewaste 9 having the length corresponding to the length of thelower damper 12 in the direction toward thegasifier 20 can be fed to thescrew conveyor 13. Also, thewaste 9 is dropped at the center in the width direction of thescrew conveyor 13 immediately after the lowerleft damper 12L and the lowerright damper 12R start to be opened (or thewaste 9 is dropped at the position of the center line Lc extending in the longitudinal direction and passing through the center in the width direction of the waste-conveying device 7). That is, thewaste 9 is dropped in the area between the pair ofconveyance screws 13a. Then, as the opening becomes larger, the area in which thewaste 9 is dropped becomes larger in a direction away from the center in the width direction. Thus, thewaste 9 has a cross section in a mound-like shape at any position in the direction toward thegasifier 20 along the pair ofconveyance screws 13a of thescrew conveyor 13. The variation in volume of thewaste 9 in the left-right direction can be reduced. The volumetric feeding performance of thewaste 9 to the gasifier is improved. - Also, in the waste-feeding
apparatus 1 according to the comparative example, the lowerleft damper 12L and the lowerright damper 12R are lowered toward the distal portions from the lower supportingshafts 12p in the closed state. The upper surfaces of the lowerleft damper 12L and the lowerright damper 12R are inclined in the closed state, and hence have a hopper-like shape. Thewaste 9 can be efficiently fed onto thescrew conveyor 13 when the lowerleft damper 12L and the lowerright damper 12R start to be opened. - Also, the
waste disintegrator 14, which disintegrates thewaste 9 pushed by thescrew conveyor 13, is provided at a forward position of the distal end of thescrew conveyor 13. Thewaste disintegrator 14 disintegrates thewaste 9 conveyed by the rotation of the pair ofconveyance screws 13a into smaller pieces. Thewaste 9 is fed into thegasifier 20 through the waste-feedingchute 8 and then through thewaste inlet 21. Thus, a large block ofwaste 9 will not be fed, contributing to improvement in volumetric feeding. In addition, toxic substances can be prevented from being produced in exhaust gas, and variation in the amount of produced gas can be reduced. The performance of a gasification and melting plant can be improved, and the allowance ratios for respective devices can be decreased. Consequently, the cost of the gasification and melting plant can be decreased. - The waste-feeding apparatus for the gasifier according to the comparative example is merely a specific example, and the design thereof can be freely changed within the technical scope of the present disclosure. The configuration of the waste-feeding apparatus for the gasifier is not limited to the above-described example.
- For example, in the above-described example not part of the invention, the waste-feeding
apparatus 1 includes theconveyor 5. However, the conveyor may be omitted, and thewaste 9 crushed by thecrusher 4 may be directly dropped and fed into thevertical chute 6. With this configuration, the installation space can be small, and the building for housing the equipment can be small. This is economically advantageous to decrease the equipment cost for the waste-feeding apparatus. - Also, the
crusher 4 may be provided separately from the waste-feedingapparatus 1. With this configuration, even when thecrusher 4 is stopped during operation because of a trouble, the waste-feedingapparatus 1 can continuously feed thewaste 9 to thegasifier 20. Accordingly, continuous operating performance can be increased. - A waste-feeding apparatus according to an embodiment of the present invention will be described below with reference to the attached drawings. The embodiment implements a waste-feeding method of the present invention. The same reference numerals refer components equivalent to those in the comparative example not part of the invention, and the same names are applied thereto throughout the description.
Fig. 3 is an explanatory view schematically showing the configuration of a waste-feeding apparatus according to an embodiment of the present invention,Fig. 3 also showing a gasifier for gasification of the waste.Fig. 4A is an explanatory view schematically showing the configurations of upper and lower dampers.Fig. 4B is an enlarged cross-sectional view showing part C inFig. 4A . -
Reference numeral 1 shown inFig. 3 denotes the waste-feeding apparatus according to an embodiment of the invention. The embodiment implements the waste-feeding method of the present invention. The waste-feedingapparatus 1 includes a vertical chute 6 (described below), a waste-conveyingdevice 7 to whichwaste 9 is fed from thevertical chute 6, and a waste-feedingchute 8 connected with the waste-conveyingdevice 7. The waste-feedingchute 8 obliquely extends and communicates with awaste inlet 21 in agasifier 20, to feed thewaste 9. To be more specific, a waste-dumping device (not shown) such as a crane feeds thewaste 9 into awaste hopper 2. Apusher 3 pushes thewaste 9. Acrusher 4 roughly crushes the pushedwaste 9. Then, aconveyor 5 provided in an air-tight conveyor housing lifts thewaste 9, which has been roughly crushed by thecrusher 4, obliquely upward. Thewaste 9 is dropped and fed into thevertical chute 6. - The
vertical chute 6 includes double dampers having a sealing function, which will be described later. The double dampers each have a rectangular cross section. The waste-conveyingdevice 7 is connected with the lower end of thevertical chute 6. The waste-conveyingdevice 7 includes a screw conveyor and a waste disintegrator, which will be described later. The screw conveyor conveys thewaste 9 toward thegasifier 20. The upper end of the waste-feedingchute 8 is connected with the lower distal end of the waste-conveyingdevice 7. The waste-feedingchute 8 extends obliquely downward and communicates with thewaste inlet 21 of thegasifier 20. - The double dampers provided in the
vertical chute 6 include anupper damper 11 and alower damper 12. Thelower damper 12 is provided below theupper damper 11 and separated from theupper damper 11 by a predetermined distance. An upper supportingshaft 11p is provided on the inner wall of thevertical chute 6 at a position close to thegasifier 20. Theupper damper 11 is rotated downward by 75° around the upper supportingshaft 11p as a pivot from a closed position inclined at 15° to a horizontal line. Theupper damper 11 is opened to a vertical position at which theupper damper 11 is orthogonal to the horizontal line. - The
lower damper 12 is provided in thevertical chute 6 at the position below theupper damper 11 and separated from theupper damper 11 by a predetermined distance. A lower supportingshaft 12p is provided on the inner wall of thevertical chute 6 at a position close to thegasifier 20. Thelower damper 12 is rotated downward by 75° around the lower supportingshaft 12p as a pivot from a closed position inclined at 15° to a horizontal line. Thelower damper 12 is opened to a vertical position at which thelower damper 12 is orthogonal to the horizontal line. - In the embodiment of the present invention, as described above, the upper and
lower dampers - Also, in the embodiment of the invention the upper and lower supporting
shafts vertical chute 6 at the positions close to thegasifier 20. However, it is not limited thereto, and the following arrangement may be employed. - (1) Both the upper and lower supporting
shafts vertical chute 6 at positions far from thegasifier 20. - (2) The lower supporting
shaft 12p may remain at the position of thevertical chute 6 close to thegasifier 20, and the upper supportingshaft 11p may be provided on the inner wall of thevertical chute 6 at the position far from thegasifier 20. - (3) The upper supporting
shaft 11p may remain at the position of thevertical chute 6 close to thegasifier 20, and the lower supportingshaft 12p may be provided on the inner wall of thevertical chute 6 at the position far from thegasifier 20. - As described in (2) and (3), when the upper and lower supporting
shafts vertical chute 6 at the opposite positions, thewaste 9 can be dropped from theupper damper 11 onto a position close to the lower supportingshaft 12p of thelower damper 12. Thus, a substance adhering to the upper surface of thelower damper 12 is continuously wiped out because thewaste 9 dropped from theupper damper 11 slides on the upper surface of thelower damper 12. The frequency of cleaning for thelower damper 12 can be reduced. The maintenance cost for the waste-feeding apparatus can be decreased. - The upper and
lower dampers Figs. 4A and 4B . Theupper damper 11 includes anupper damper body 11a and an upper supportingarm 11h. Theupper damper body 11a includes a damper substrate 11b made of, for example, a SS member or a SUS member, and a hard low-friction resin plate 11c fixed to the upper surface of the damper substrate 11b. The upper supportingarm 11h has one end that is rotatably supported by the upper supportingshaft 11p, and the other end that rotatably supports theupper damper body 11a through a bracket 11e and acoupling pin 11f. - The hard low-
friction resin plate 11c is fixed to the upper surface of the damper substrate 11b by a plurality of small flat-head screws 11d (mechanical fastening means) that are respectively screwed into a plurality ofinternal threads 11s formed in the damper substrate 11b. - Also,
coating layers 11g each having an inverted cone shape are provided to fill spaces above the upper surfaces of the small flat-head screws 11d housed in inverted-cone-shaped screw-head housing holes in the hard low-friction resin plate 11c, so that the upper surfaces of thecoating layers 11g are flush with the surface of the hard low-friction resin plate 11c. The coating layers 11g prevent corrosive substances from contacting the upper surfaces of the small flat-head screws 11d, and prevent magnetic substances contained in thewaste 9 from adhering thereto. - An
upper arm 11i has one end fixed to a shaft end of the upper supportingshaft 11p that supports the upper supportingarm 11h, the shaft end protruding from thevertical chute 6. An expansion rod of anupper cylinder 11j has a distal end pivotally attached to a distal end of theupper arm 11i. When the expansion rod of theupper cylinder 11j is expanded and contracted, theupper damper body 11a is rotated by 75° through theupper arm 11i, the upper supportingshaft 11p, and the upper supportingarm 11h. - The
lower damper 12 includes alower damper body 12a and a lower supportingarm 12h. Thelower damper body 12a includes a damper substrate 12b made of, for example, a SS member or a SUS member, and a hard low-friction resin plate 12c fixed to the upper surface of the damper substrate 12b. The lower supportingarm 12h has one end that is rotatably supported by the lower supportingshaft 12p, and the other end that rotatably supports thelower damper body 12a through a bracket 12e and acoupling pin 12f. - The hard low-
friction resin plate 12c is fixed to the upper surface of the damper substrate 12b by a plurality of small flat-head screws 12d (mechanical fastening means) that are respectively screwed into a plurality ofinternal threads 12s formed in the damper substrate 12b. - Also,
coating layers 12g each having an inverted cone shape are provided to fill spaces above the upper surfaces of the small flat-head screws 12d housed in inverted-cone-shaped screw-head housing holes in the hard low-friction resin plate 12c, so that the upper surfaces of thecoating layers 12g are flush with the surface of the hard low-friction resin plate 12c. The coating layers 12g prevent corrosive substances from contacting the upper surfaces of the small flat-head screws 12d, and prevent magnetic substances contained in thewaste 9 from adhering thereto. - A
lower arm 12i has one end fixed to a shaft end of the lower supportingshaft 12p that supports the lower supportingarm 12h, the shaft end protruding from thevertical chute 6. An expansion rod of alower cylinder 12j has a distal end pivotally attached to a distal end of thelower arm 12i. When the expansion rod of thelower cylinder 12j is expanded and contracted, thelower damper body 12a is rotated by 75° through thelower arm 12i, the lower supportingshaft 12p, and the lower supportingarm 12h. As described above in detail, theupper damper 11 and thelower damper 12 have the same operation mechanisms. - The hard low-
friction resin plate 11c in theupper damper body 11a and the hard low-friction resin plate 12c in thelower damper body 12a each are made of ultra high molecular weight polyethylene resin with an ultra high molecular weight of three millions to eight millions. In this embodiment, as described above, the ultra high molecular weight polyethylene resin has been used. However, it is not limited thereto. For example, polycarbonate (PC) resin or acrylonitrile butadiene styrene (ABS) resin may be used. That is, the material of the hard low-friction resin plate is not limited to particular types of resin as long as the material has good wear resistance, good shock resistance, and good chemical resistance. - The
upper damper 11 and thelower damper 12 are alternately opened and closed such that at least one of theupper damper 11 and thelower damper 12 is closed, in order to inhibit external air from entering thegasifier 20. - The waste-conveying
device 7 houses ascrew conveyor 13 that conveys thewaste 9 fed through thelower damper 12 toward thegasifier 20. Thescrew conveyor 13 includes a pair ofconveyance screws 13a having rotation centers parallel to one another in a horizontal plane. In addition, awaste disintegrator 14 is provided at the distal side of thescrew conveyor 13 at a position not occupied by thescrew conveyor 13. Thewaste disintegrator 14 disintegrates thewaste 9 pushed by thescrew conveyor 13. Thewaste disintegrator 14 in the embodiment is rotary type; however, a configuration of rocking type may be used. - The operation mode of the waste-feeding
apparatus 1 having the above-described configuration will be described below. Thepusher 3 pushes thewaste 9 fed into thewaste hopper 2. Thecrusher 4 roughly crushes the pushedwaste 9. Theconveyor 5 lifts thewaste 9, which has been roughly crushed by thecrusher 4, obliquely upward. Thewaste 9 is dropped and fed onto theupper damper 11 of thevertical chute 6. - When the
waste 9 is stacked on the upper surface of theupper damper 11 by a predetermined amount, theupper damper 11 is opened, and then closed after several seconds has elapsed. During this period, thewaste 9 stacked on theupper damper 11 by the predetermined amount and thewaste 9 lifted obliquely upward by theconveyor 5 are fed onto the upper surface of thelower damper 12. When several seconds has elapsed after theupper damper 11 is closed, thelower damper 12 is opened and the open state is maintained for several seconds. Thus, thewaste 9 fed onto thelower damper 12 is dropped on thescrew conveyor 13, more particularly, on the pair ofconveyance screws 13a. - The
waste 9 dropped on the pair ofconveyance screws 13a is conveyed by rotation of the pair ofconveyance screws 13a. Thewaste disintegrator 14 disintegrates thewaste 9 discharged from the distal end of thescrew conveyor 13 into smaller pieces. Thewaste 9 is fed into thegasifier 20 through the waste-feedingchute 8 and then through thewaste inlet 21. Thewaste 9 fed into thegasifier 20 is gasified at temperatures from 500°C to 600°C, and decomposed into combustible gas, fixed carbon, and ash. - Then, the decomposed combustible gas and fixed carbon are burned in a melting furnace (not shown). The ash is molten at temperatures of 1300°C or higher, and becomes molten slag. The
lower damper 12 is closed when several seconds has elapsed after thewaste 9 is fed to thescrew conveyor 13. Then, theupper damper 11, which has been previously closed, is opened. In this way, theupper damper 11 and thelower damper 12 are alternately opened and closed at an interval of predetermined seconds. - In the waste-feeding
apparatus 1 according to an embodiment of the present invention, in the above-described process, the upper surfaces of theupper damper body 11a and thelower damper body 12a are formed of the hard low-friction resin plates. Even when a sealing surface (not shown) formed on thevertical chute 6 is made of metal, a spark does not occur due to an impact exerted when either damper is closed. Thus, oil contained in thewaste 9 is not ignited with the spark. Also, magnetized waste does not adhere to either damper. This can prevent the phenomenon from occurring, the phenomenon in which the magnetized waste adheres to the damper, another magnetized waste is hooked to the adhering magnetized waste, resulting in the waste being accumulated, and hence the waste cannot be smoothly fed into the gasifier. Further, the damper has a low friction coefficient. Thus, the sealing performance is not deteriorated. - A waste-feeding apparatus according to the further comparative example not part of the invention will be described below with reference to the attached drawings. The further comparative example implements a waste-feeding method not part of the invention. The same reference numerals refer components equivalent to those in the aforementioned embodiment, and the same names are applied thereto throughout the description.
Fig. 5 is an explanatory view schematically showing the configuration of a pressure generator and a control device that controls the pressure generator, the pressure generator operating upper and lower cylinders of upper and lower dampers in a waste-feeding apparatus according to the further comparative example. The waste-feeding apparatus according to the further comparative example not part of the invention has the same configuration as the embodiment of the invention. The configuration of the waste-feeding apparatus will be described with reference toFig. 3 . -
Reference numeral 1 shown inFig. 3 denotes the waste-feeding apparatus according to an embodiment of the present invention, which implements a waste-feeding method part of the invention. The waste-feedingapparatus 1 includes a vertical chute 6 (described below), a waste-conveyingdevice 7 to whichwaste 9 is fed from thevertical chute 6, and a waste-feedingchute 8 connected with the waste-conveyingdevice 7. The waste-feedingchute 8 obliquely extends and communicates with awaste inlet 21 in agasifier 20, to feed thewaste 9. To be more specific, a waste-dumping device (not shown) such as a crane feeds thewaste 9 into awaste hopper 2. Apusher 3 pushes thewaste 9. Acrusher 4 roughly crushes the pushedwaste 9. Then, aconveyor 5 provided in an air-tight conveyor housing lifts thewaste 9, which has been roughly crushed by thecrusher 4, obliquely upward. Thewaste 9 is dropped and fed into thevertical chute 6. In the further comparative example not part of the invention, waste primary feeding means includes thewaste hopper 2, thepusher 3, thecrusher 4, and theconveyor 5. - The
vertical chute 6 includes double dampers having a sealing function, which will be described later. The double dampers each have a rectangular cross section. The waste-conveyingdevice 7 is connected with the lower end of thevertical chute 6. The waste-conveyingdevice 7 includes a screw conveyor and a waste disintegrator, which will be described later. The screw conveyor conveys thewaste 9 toward thegasifier 20. The upper end of the waste-feeding conveyingdevice 7. The waste-feedingchute 8 extends obliquely downward and communicates with thewaste inlet 21 of thegasifier 20. - The double dampers provided in the
vertical chute 6 include anupper damper 11 and alower damper 12. Thelower damper 12 is provided below theupper damper 11 and separated from theupper damper 11 by a predetermined distance. An upper supportingshaft 11p is provided on the inner wall of thevertical chute 6 at a position close to thegasifier 20. Theupper damper 11 is rotated downward by 75° around the upper supportingshaft 11p as a pivot from a closed position inclined at 15° to a horizontal line. Theupper damper 11 is opened to a vertical position at which theupper damper 11 is orthogonal to the horizontal line. - The
lower damper 12 is provided in thevertical chute 6 at the position below theupper damper 11 and separated from theupper damper 11 of thevertical chute 6 by a predetermined distance. A lower supportingshaft 12p is provided on the inner wall of thevertical chute 6 at a position close to thegasifier 20. Thelower damper 12 is rotated downward by 75° around the lower supportingshaft 12p as a pivot from a closed position inclined at 15° to a horizontal line. Thelower damper 12 is opened to a vertical position at which thelower damper 12 is orthogonal to the horizontal line. - In the further comparative example, as described above, the upper supporting
shaft 11p and the lower supportingshaft 12p are provided on the inner wall of thevertical chute 6 at the positions close to the gasifier 20 (at the right side inFigs. 3 and5 ). - However, a similar advantage can be attained even when the upper supporting
shaft 11p and the lower supportingshaft 12p are provided on the inner wall of thevertical chute 6 at positions far from the gasifier 20 (at the left side inFigs. 3 and5 ). In the further comparative example, theupper damper 11 and thelower damper 12 are inclined by 15° to the horizontal line in the closed state. However, the inclination angle of the upper andlower dampers - The
upper damper 11 and thelower damper 12 are opened and closed by upper andlower cylinders Fig. 5 . In particular, anupper arm 11i has one end fixed to a shaft end of the upper supportingshaft 11p that rotatably supports theupper damper 11, the shaft end protruding from thevertical chute 6. An expansion rod of anupper cylinder 11j has a distal end pivotally attached to a distal end of theupper arm 11i. When the expansion rod of theupper cylinder 11j is expanded and contracted, theupper damper 11 is rotated by 75° through theupper arm 11i and the upper supportingshaft 11p to be opened and closed (theupper damper 11 being closed when the expansion rod is contracted, and opened when the expansion rod is expanded). Also, a limit switch 11sw is provided. The limit switch 11sw contacts theupper arm 11i when theupper arm 11i rotates theupper damper 11 to the closed position. Then, the limit switch 11sw detects that theupper damper 11 is at the closed position, and transmits the detection signal to the control device CL (described below). - A
lower arm 12i has one end fixed to a shaft end of the lower supportingshaft 12p that rotatably supports thelower damper 12, the shaft end protruding from thevertical chute 6. An expansion rod of alower cylinder 12j has a distal end pivotally attached to a distal end of thelower arm 12i. When the expansion rod of thelower cylinder 12j is expanded and contracted, thelower damper 12 is rotated by 75° through thelower arm 12i and the lower supportingshaft 12p to be opened and closed (thelower damper 12 being closed when the expansion rod is contracted, and opened when the expansion rod is expanded). As described above in detail, the upper andlower dampers lower dampers - The expansion rods of the upper and
lower cylinders lower dampers upper arm 11i. In other words, the control device CL receives a damper-closed signal indicating that theupper damper 11 has been closed. To be more specific, if the control device CL receives the damper-closed signal from the limit switch 11sw, the control device CL determines that thewaste 9 is not caught by theupper damper 11, and controls the pressure generator PU to alternately operate the upper andlower cylinders - In contrast, if the control device CL does not receive the damper-closed signal from the limit switch 11sw, the control device CL determines that the
waste 9 is caught by theupper damper 11, stops the control of the pressure generator PU that normally operates the upper andlower cylinders pusher 3 and theconveyor 5 as described below. - In this case, the determination that the
waste 9 is caught by theupper damper 11 is made as follows. A timer (not shown) counts the elapsed time since the operation of theupper cylinder 11j has been started to close the upper damper 11 (or since the expansion of the expansion rod has been started). If the damper-closed signal is not output from the limit switch 11sw although a predetermined period (for example, 5 to 10 seconds) has been elapsed, the counting operation is stopped, and it is determined that thewaste 9 is caught by theupper damper 11. The set period of the timer can be changed depending on the opening and closing speed of theupper damper 11. With this configuration, the unused stop period of the waste-feedingapparatus 1 can be decreased. Thus, the time required for removing thewaste 9 caught by theupper damper 11 can be decreased. - If it is determined that the
waste 9 is caught by theupper damper 11, the operation of thepusher 3 and theconveyor 5 is stopped by the control device CL, and hence feeding of thewaste 9 to thevertical chute 6 is temporality stopped. During the stop of the feeding of thewaste 9, the pressure generator PU is controlled to operate theupper cylinder 11j. Thus, theupper damper 11 is opened so that thewaste 9 caught by theupper damper 11 is dropped and removed. After theupper damper 11, which has been opened for the removal of the caughtwaste 9, is closed, the operation of thepusher 3 and theconveyor 5 is controlled to be started so that feeding of thewaste 9 to thevertical chute 6 is started. - In this case, the removal of the
waste 9 caught by theupper damper 11 is determined if the damper-closed signal output from the limit switch 11sw is received. Theupper damper 11 and thelower damper 12 are alternately opened and closed such that at least one of theupper damper 11 and thelower damper 12 is closed, in order to inhibit external air from entering thegasifier 20. - The waste-conveying
device 7 houses ascrew conveyor 13 that conveys thewaste 9 fed through thelower damper 12 toward thegasifier 20. Thescrew conveyor 13 includes a pair ofconveyance screws 13a having rotation centers parallel to one another in a horizontal plane (inFig. 3 , however, only one of theconveyance screws 13a is shown). In addition, awaste disintegrator 14 is provided at the distal side of thescrew conveyor 13 at a position not occupied by thescrew conveyor 13. Thewaste disintegrator 14 disintegrates thewaste 9 pushed by thescrew conveyor 13. Thewaste disintegrator 14 in the further comparative example is rotary type; however, a configuration of rocking type may be used. - The operation mode of the waste-feeding
apparatus 1 having the above-described configuration for implementing a waste-feeding method will be described below. Thepusher 3 pushes thewaste 9 fed into thewaste hopper 2. Thecrusher 4 roughly crushes the pushedwaste 9. Theconveyor 5 lifts thewaste 9, which has been roughly crushed by thecrusher 4, obliquely upward. Thewaste 9 is dropped and fed onto theupper damper 11 of thevertical chute 6. - When the
waste 9 is stacked on theupper damper 11 by a predetermined amount, theupper damper 11 is opened, and then closed after several seconds has elapsed. During this period, thewaste 9 stacked on theupper damper 11 by the predetermined amount and thewaste 9 lifted obliquely upward by theconveyor 5 are fed onto thelower damper 12. When several seconds has elapsed after theupper damper 11 is closed, thelower damper 12 is opened and the open state is maintained for several seconds. Thus, thewaste 9 fed onto thelower damper 12 is dropped on thescrew conveyor 13, more particularly, on the pair ofconveyance screws 13a. - The
waste 9 dropped on the pair ofconveyance screws 13a is conveyed by rotation of the pair ofconveyance screws 13a. Thewaste disintegrator 14 disintegrates thewaste 9 discharged from the distal end of thescrew conveyor 13 into smaller pieces. Thewaste 9 is fed into thegasifier 20 through the waste-feedingchute 8 and then through thewaste inlet 21. Thewaste 9 fed into thegasifier 20 is gasified at temperatures from 500°C to 600°C, and decomposed into combustible gas, fixed carbon, and ash. Then, the decomposed combustible gas and fixed carbon are burned in a melting furnace (not shown). The ash is molten at temperatures of 1300°C or higher, and becomes molten slag. - Meanwhile, in the further comparative example, the
lower damper 12 is closed when several seconds has elapsed after thewaste 9 is fed to thescrew conveyor 13. Then, theupper damper 11, which has been previously closed, is opened. In this way, theupper damper 11 and thelower damper 12 are repeatedly alternately opened and closed at an interval, for example, from 15 seconds to 3 minutes. The interval of the operation for opening and closing each of the upper andlower dampers - In the above-described process, when the
waste 9 is caught by theupper damper 11, the limit switch 11sw is not operated because the expansion rod does not achieve the minimum stroke (the most contracted state) although the closing operation of theupper damper 11 is selected, in which the expansion rod of theupper cylinder 11j is contracted. Thus, the damper-closed signal is not transmitted to the control device CL. Then, the control device CL outputs an operation stop instruction signal, and hence the operation of thepusher 3 and theconveyor 5 is stopped. Accordingly, feeding of thewaste 9 to thevertical chute 6 is temporarily stopped. - During the stop of the feeding of the
waste 9, under the control of the control device CL, the pressure generator PU switches the operation to the opening operation of theupper damper 11, in which the expansion rod of theupper cylinder 11j is expanded, to open theupper damper 11. Thus, thewaste 9 caught by theupper damper 11 is removed. Then, the expansion rod of theupper cylinder 11j is contacted to close theupper damper 11, which has been opened for removal of the caughtwaste 9. If the control device CL receives the damper-closed signal, the operation of thepusher 3 and theconveyor 5 is started to start the feeding of thewaste 9 to thevertical chute 6. Thereafter, the operation state is recovered to the normal operation state. - In the waste-feeding
apparatus 1 according to the further comparative example not part of the invention for implementing a waste-feeding method not part of the invention, in some cases, thewaste 9 cannot be removed although theupper damper 11 has been opened for the removal of the caughtwaste 9, and the damper-closed signal cannot be received although theupper damper 11 has been operated to be closed. - In such a case, the opening and closing operation for the
upper damper 11 is repeated until the damper-closed signal is received. By repeating the opening and closing operation for theupper damper 11, external air can be reliably inhibited from entering thegasifier 20. At the same time, the operating ratio of the waste-feedingapparatus 1 and the waste-processing amount may be degraded. However, the time required for repeating the opening and closing operation is markedly shorter than the time required for removing thewaste 9 by opening an access hole. Thus, the operating ratio of the waste-feedingapparatus 1 and the waste-processing amount can be less degraded. - With the waste-feeding method by the waste-feeding
apparatus 1 according to the further comparative example, the above-described operation is carried out when thewaste 9 is caught by theupper damper 11. In contrast, if the control device CL receives the damper-closed signal, and it is determined that theupper damper 11 is completely closed and thewaste 9 is not caught by theupper damper 11, the feeding of thewaste 9 to thevertical chute 6 is continued, and the operation of the waste primary feeding means located upstream of thevertical chute 6, that is, the operation of thepusher 3 and theconveyor 5 is not stopped. The following advantages can be attained. - (1) Since the operation of the waste primary feeding means located at the upstream side is less frequently started and stopped, the life of the waste primary feeding means is not decreased, and hence, the operating cost can be decreased.
- (2) The volumetric feeding performance of the
waste 9 is hardly deteriorated, the processing efficiency of thewaste 9 is increased, and the variation in the amount of produced gas, which is gasified in thegasifier 20, can be decreased. Thus, it is easy to carry out the control for stable gasification operation of thegasifier 20 and the control for stable operation of the melting furnace located downstream of thegasifier 20. - (3) Since at least one limit switch is required, the configuration of the control system including the pressure generator and the control device for controlling the operation of the
upper cylinder 11j does not become complicated or expensive. - A waste-feeding apparatus according to the modified further comparative example not part of the invention will be described below with reference to
Fig. 6 , which is an explanatory view schematically showing the configuration of a pressure generator and a control device that controls the pressure generator, the pressure generator operating upper and lower cylinders of upper and lower dampers. The modified further comparative example has a configuration similar to that of the further comparative example except for the position of a lower supporting shaft that rotatably supports a lower damper. The same reference numerals refer components equivalent to those in the further comparative example or components having the same functions as those in the further comparative example. The point of the modified further comparative example different from the further comparative example will be mainly described. - Similar to the further comparative example not part of the invention, an upper supporting
shaft 11p is provided on the inner wall of thevertical chute 6 at a position close to the gasifier 20 (at the right side inFig. 6 ). Theupper damper 11 is rotated downward by 75° around the upper supportingshaft 11p as a pivot from a closed position inclined at 15° to a horizontal line. Theupper damper 11 is opened to a vertical position at which theupper damper 11 is orthogonal to the horizontal line. A lower supportingshaft 12p is provided on the inner wall of thevertical chute 6 at a position far from the gasifier 20 (at the left side inFig. 6 ). Thelower damper 12 is rotated downward by 75° around the lower supportingshaft 12p as a pivot from a closed position inclined at 15° to a horizontal line. Thelower damper 12 is opened to a vertical position at which thelower damper 12 is orthogonal to the horizontal line. - Thus, in the waste-feeding apparatus according to the modified further comparative example not part of the invention for implementing the waste-feeding method not part of the invention, only the position of the lower supporting
shaft 12p that rotatably supports thelower damper 12 is different. Thus, a similar advantage to that of the waste-feeding apparatus according to the further comparative example can be attained. Also, in the waste-feeding apparatus according to the modified further comparative example, thewaste 9 is dropped from theupper damper 11 toward the lower supportingshaft 12p of thelower damper 12, slides on the upper surface of thelower damper 12, and is dropped onto the position close to the next process. Thus, thewaste 9 can be prevented from adhering to the upper surface of thelower damper 12, and thewaste 9 on the upper surface of thelower damper 12 can be removed by wiping effect of thewaste 9 as a result of sliding. The interval for cleaning of thelower damper 12 can be increased, the operating cost of the waste-feeding apparatus can be decreased, and the operating ratio can be improved. - In the further comparative example not part of the invention and the modified further comparative example not part of the invention, the
upper damper 11 is opened and closed when thewaste 9 is caught by theupper damper 11, and it is determined that the caughtwaste 9 has been removed in response to the damper-closed signal from the limit switch 11sw. However, it is preferable to add a configuration for removing thewaste 9 caught by thelower damper 12, to the waste-feeding apparatus having the configuration for removing thewaste 9 caught by theupper damper 11. Thewaste 9 is less frequently caught by thelower damper 12 as compared with theupper damper 11. However, as the apparatus is operated for a long term, thelower damper 12 may not become completely closed, for example, due to a muddy substance adhering onto the damper surface. - More specifically, in the further modified further comparative example, a limit switch (not shown) is provided. The limit switch contacts a
lower arm 12i when alower cylinder 12j makes a minimum stroke, detects that thelower damper 12 is at a closed position, and transmits the detection signal to the control device CL. If the control device CL does not receive the damper-closed signal from the limit switch although thelower cylinder 12j, which opens and closes thelower damper 12, has been operated to close thelower damper 12 and a predetermined time counted by a timer has been elapsed, it is determined that thewaste 9 is caught by thelower damper 12. Thelower damper 12 is opened to remove the caughtwaste 9, and then the openlower damper 12 is closed. After the operation, if the control device CL receives the damper-closed signal from the limit switch, it is determined that thewaste 9 caught by thelower damper 12 is removed. Theupper damper 11 is opened, so that thewaste 9 stacked on theupper damper 11 is dropped and fed onto thelower damper 12. - With the waste-feeding method according to further modified further comparative example, in addition to the advantages of the waste-feeding method according to further comparative example and modified further comparative example, it can be recognized that the
waste 9 is caught by thelower damper 12. Also, thewaste 9 caught by thelower damper 12 can be reliably removed. Thus, thewaste 9 is not accumulated or stayed on thelower damper 12 as a result of thewaste 9 being caught by thelower damper 12. Thewaste 9 can be reliably conveyed by the waste-conveyingdevice 7 and fed into thewaste inlet 21, the volumetric feeding performance for thewaste 9 is hardly deteriorated, and the processing efficiency for thewaste 9 can be increased. Also, the unused stop period of the waste-feeding apparatus can be decreased. Thus, the time required for removing thewaste 9 caught by thelower damper 12 can be decreased. Since at least two limit switches are required, the configuration of the control system for controlling damper operating means does not become complicated or expensive. - Meanwhile, in the waste-feeding
apparatus 1 according to any of further comparative example, modified further comparative example, and further modified further comparative example (none of which being part of the invention), the upper and lower dampers are closed when the upper and lower cylinders are contracted, and the upper and lower dampers are opened when the upper and lower dampers are expanded. However, it is not limited thereto. The upper and lower dampers may be closed when the upper and lower cylinders are expanded, and the upper and lower dampers may be opened when the upper and lower cylinders are contacted (for example, the directions of the arms may be opposite to the directions shown inFigs. 5 and6 , or if the directions of the arms are the same as the directions shown inFigs. 5 and6 , the upper and lower cylinders may be configured such that the expansion rods are expanded downward). - The waste-feeding apparatus according to any of the above-described embodiments part of the invention and comparative examples not part of the invention, and the waste-feeding apparatus according to any of the above-described embodiments for implementing the waste-feeding methods of the present invention and comparative examples not part of the invention for implementing the waste-feeding methods not part of the invention, are merely examples of the present invention, and the design thereof can be feely changed within the technical scope of the present invention. Therefore, the configuration of the waste-feeding apparatus is not limited to the configuration of the waste-feeding
apparatus 1 according to any of the above-described embodiments and comparative examples.
Claims (4)
- A waste-feeding apparatus (1), comprising:a vertical chute (6) including upper and lower dampers (11, 12) separated from one another by a predetermined distance in an up-down direction, the upper and lower dampers (11, 12) having a sealing function that inhibits external air from entering a gasifier (20) and configured to be alternately opened and closed; anda waste-conveying device (7) configured to convey waste (9), which has been fed through the vertical chute (6), toward the gasifier (20),wherein the upper and lower dampers (11, 12) have damper bodies (11a, 12a), whereineach of the damper bodies (11a, 12a) has a damper substrate (11b, 12b), characterized in that each of said damper bodies (11a,12a) has a hard low-friction resin plate (11c, 12c) fixed to an upper surface of the damper substrate (11b, 12b) by mechanical fastening means, andwherein, when the upper or lower damper (11, 12) is closed, an upper surface of an outer edge portion of the hard low-friction resin plate (11c, 12c) contacts a sealing surface formed on an inner side of the vertical chute (6).
- The waste-feeding apparatus (1) according to claim 1, wherein the mechanical fastening means is a small flat-head screw (11d, 12d) that is screwed into an internal thread (11s, 12s) formed in the damper substrate (11b, 12b) such that an upper surface of a screw head is lower than an upper surface of the hard low-friction resin plate (11c, 12c), and
wherein a resin coating layer (11g, 12g) is formed on the upper surface of the screw head. - The waste-feeding apparatus (1) according to claim 2, wherein
the resin coating layer (11g, 12g) is flush with a surface of the hard low-friction resin plate (11c, 12c). - A sealing method of a waste-feeding apparatus (1) for inhibiting external air from entering a gasifier (20),
wherein the waste-feeding apparatus (1) includes
a vertical chute (6) including upper and lower dampers (11, 12) having a hard low-friction resin plate (11c, 12c) fixed to an upper surface of a damper substrate (11b, 12b) by mechanical fastening means, said dampers (11,12) being separated from one another by a predetermined distance in an up-down direction, and
a waste-conveying device (7) configured to convey waste (9), which has been fed through the vertical chute (6), toward the gasifier (20),
the sealing method comprising the step of: when the upper and lower dampers (11, 12) are alternately closed for sealing, bringing an upper surface of an outer edge portion of a hard low-friction resin plate (11c, 12c) of a damper body (11a, 12a) into contact with a sealing surface formed on an inner side of the vertical chute (6).
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2007214926A JP4546508B2 (en) | 2007-08-21 | 2007-08-21 | Waste supply device for gasifier and waste supply method to gasifier |
JP2007241197 | 2007-09-18 | ||
JP2007257584A JP4829863B2 (en) | 2007-10-01 | 2007-10-01 | Waste supply device and sealing method thereof |
JP2008200757A JP4829939B2 (en) | 2007-09-18 | 2008-08-04 | Waste supply method |
PCT/JP2008/065057 WO2009025378A1 (en) | 2007-08-21 | 2008-08-15 | Waste feeding apparatus, its sealing method, and waste feeding method |
EP08792666.3A EP2180255B1 (en) | 2007-08-21 | 2008-08-15 | Waste feeding apparatus and waste feeding method |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP08792666.3A Division EP2180255B1 (en) | 2007-08-21 | 2008-08-15 | Waste feeding apparatus and waste feeding method |
EP08792666.3A Division-Into EP2180255B1 (en) | 2007-08-21 | 2008-08-15 | Waste feeding apparatus and waste feeding method |
Publications (2)
Publication Number | Publication Date |
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EP3112754A1 EP3112754A1 (en) | 2017-01-04 |
EP3112754B1 true EP3112754B1 (en) | 2019-01-02 |
Family
ID=42046239
Family Applications (3)
Application Number | Title | Priority Date | Filing Date |
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EP16174338.0A Active EP3112753B1 (en) | 2007-08-21 | 2008-08-15 | Waste-feeding method |
EP16174339.8A Active EP3112754B1 (en) | 2007-08-21 | 2008-08-15 | Waste-feeding apparatus and sealing method thereof |
EP08792666.3A Active EP2180255B1 (en) | 2007-08-21 | 2008-08-15 | Waste feeding apparatus and waste feeding method |
Family Applications Before (1)
Application Number | Title | Priority Date | Filing Date |
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EP16174338.0A Active EP3112753B1 (en) | 2007-08-21 | 2008-08-15 | Waste-feeding method |
Family Applications After (1)
Application Number | Title | Priority Date | Filing Date |
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EP08792666.3A Active EP2180255B1 (en) | 2007-08-21 | 2008-08-15 | Waste feeding apparatus and waste feeding method |
Country Status (3)
Country | Link |
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EP (3) | EP3112753B1 (en) |
KR (1) | KR101166848B1 (en) |
WO (1) | WO2009025378A1 (en) |
Families Citing this family (4)
Publication number | Priority date | Publication date | Assignee | Title |
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KR101166848B1 (en) | 2007-08-21 | 2012-07-19 | 가부시키가이샤 신코간교오솔루션 | Waste feeding apparatus, its sealing method, and waste feeding method |
JP5285480B2 (en) * | 2009-03-19 | 2013-09-11 | 株式会社神鋼環境ソリューション | Waste supply device |
ITUB20153319A1 (en) * | 2015-09-01 | 2017-03-01 | Verde Ind S R L | PLANT FOR ENERGY VALORISATION OF HEALTH WASTE AND RELATED PACKAGING |
CN110003954B (en) * | 2019-03-27 | 2024-03-26 | 湖南人文科技学院 | Isolation inserting plate type feeding sealing device and updraught gasifier with same |
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2008
- 2008-08-15 KR KR1020107003589A patent/KR101166848B1/en active IP Right Grant
- 2008-08-15 EP EP16174338.0A patent/EP3112753B1/en active Active
- 2008-08-15 EP EP16174339.8A patent/EP3112754B1/en active Active
- 2008-08-15 EP EP08792666.3A patent/EP2180255B1/en active Active
- 2008-08-15 WO PCT/JP2008/065057 patent/WO2009025378A1/en active Application Filing
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Also Published As
Publication number | Publication date |
---|---|
EP2180255A1 (en) | 2010-04-28 |
EP2180255A4 (en) | 2015-12-23 |
KR101166848B1 (en) | 2012-07-19 |
EP3112754A1 (en) | 2017-01-04 |
EP3112753A1 (en) | 2017-01-04 |
EP2180255B1 (en) | 2018-10-10 |
EP3112753B1 (en) | 2019-06-26 |
KR20100037643A (en) | 2010-04-09 |
WO2009025378A1 (en) | 2009-02-26 |
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