CN111094522B

CN111094522B - Fuel manufacturing device and method for biomass burner

Info

Publication number: CN111094522B
Application number: CN201880058171.6A
Authority: CN
Inventors: 下濑真一
Original assignee: Shimase Institute Of Microbiology Ltd
Current assignee: Shimase Institute Of Microbiology Ltd
Priority date: 2017-09-19
Filing date: 2018-08-31
Publication date: 2021-09-10
Anticipated expiration: 2038-08-31
Also published as: PH12020500516A1; CN111094522A; WO2019058928A1; JP2019056023A; JP6763576B2

Abstract

The object of the present invention is to heat waste such as garbage under reduced pressure using a fermentation drying apparatus 3 and to ferment the waste with microorganisms to use the waste as fuel for a biomass burner. The solution is that the device comprises: a fermentation drying device 3 that accommodates waste (object to be treated) containing organic waste in a tank 30 (closed container), heats the waste to a predetermined temperature range under reduced pressure while stirring, and ferments the organic matter with microorganisms to obtain a dried product in which malodorous components are decomposed and the volume of the dried product is reduced; a vibrating screen machine 4 for classifying the dried material obtained by the fermentation drying device 3 into a suitable fuel (small-sized material) suitable for combustion in the biomass burner and a fuel (large-sized material) other than the suitable fuel; and a storage device 6 that temporarily stores at least the suitable fuel. The particulate matter is burned in the biomass burner 71, and the organic waste contained in the tank 30 is heated by the generated heat.

Description

Fuel manufacturing device and method for biomass burner

Technical Field

The present invention relates to a fuel production apparatus and a production method using a biomass burner for fermentation and drying of a treatment object containing organic waste.

Background

Conventionally, for example, fossil fuels such as petroleum, coal, and natural gas have been used as fuels for power generation burners, and these fuels are not preferable from the viewpoint of environmental protection. Further, for example, there has been proposed a method of incinerating general waste and industrial waste to use heat, but the object to be treated includes various organic wastes such as garbage, domestic waste water, animal and plant residues and sludge, and also includes waste having a high water content, and therefore cannot be used as a fuel for heat use. In order to utilize heat by using a fuel other than fossil fuel, a powder burner has been proposed as a biomass burner, in which a combustible material such as wood is processed into a powder form to be used as a fuel.

In this regard, the present inventors have already filed a patent application for an apparatus (fermentation drying apparatus) capable of efficiently removing water and drying by accommodating an object to be treated containing organic waste such as kitchen waste in a closed container such as a tank and heating the object to a predetermined temperature range under reduced pressure while stirring, and promoting fermentation of the organic matter by adding a predetermined microorganism to the object to be treated.

For example, in the fermentation drying apparatus described in patent document 1, the inside of the closed container is depressurized to promote evaporation of moisture from the organic waste therein, thereby shortening the drying time, and the depressurization reduces the boiling point of water, so that an excessively high temperature is not required, and the death of microorganisms due to the temperature increase can be prevented.

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 2007-319738

Disclosure of Invention

Problems to be solved by the invention

However, when wood chips or dried organic matter called biomass is burned as fuel in a biomass burner, the particle size, particle shape, water content, and the like are not uniform, and stable combustion cannot be achieved. In addition, there is a problem that a fuel supply portion toward the combustor is clogged. Since the generation of malodors cannot be suppressed by simply drying organic substances, there is a problem that the surrounding environment is deteriorated when the organic substances are stored as fuel.

In view of such circumstances, an object of the present invention is to use a known fermentation and drying apparatus for heating a treatment object containing organic waste under reduced pressure, fermenting and drying the object by using microorganisms, and then using the object as a fuel for a biomass burner.

Means for solving the problems

In order to solve the above problems, the present invention is configured to burn a fuel treated by a fermentation drying apparatus in a biomass burner and stably convert the generated thermal energy into electric energy.

That is, the fuel production apparatus using the biomass burner according to the present invention includes a fermentation drying apparatus for, as in the above-described conventional example, accommodating an object to be treated including organic waste in a closed container, heating the object to be treated to a predetermined temperature range while stirring the object under reduced pressure, and fermenting the object with a microorganism to obtain a dried product in which a malodorous component is decomposed and the volume of the dried product is reduced.

The method comprises the following steps: a classifying device for classifying the dried material obtained by the fermentation drying device into a suitable fuel suitable for combustion in the biomass burner and other fuels; and a storage device that temporarily stores at least the above-described suitable fuel. If the appropriate fuel is burned in the biomass burner, the generated thermal energy can be stably converted into electric energy.

With this configuration, the fuel production apparatus of the present invention can efficiently dry organic waste by the fermentation and drying apparatus, and promote fermentation of organic substances by microorganisms to decompose malodorous components, as in the conventional example (patent document 1). Further, if the dried product obtained in this way is classified into, for example, a large particle and a small particle, the particle size, particle shape, water content, and the like of the small particle are uniform, and generation of malodor is suppressed, and therefore, the dried product is suitable as a fuel for a biomass burner.

That is, since various organic substances are generally contained in the treatment target substances discharged from homes, various businesses, and the like, and the amounts of heat generated are different from each other, the variation in the amount of heat obtained when drying and burning the substances becomes large. For this reason, the dried material treated by the fermentation drying apparatus may be classified into a relatively large-sized material and a relatively small-sized material, and at least the small-sized material may be temporarily stored.

The waste to be treated is generally mixed with a non-organic material such as plastic, and the waste is classified into the above-mentioned large particles without changing its size even when subjected to fermentation and drying treatment. On the other hand, the organic waste (dried material) fermented and dried in the fermentation and drying device is classified mainly as small particles in addition to the large particles described above, and is converted into a fuel for a biomass burner, which is promoted to be homogenized by fermentation and drying and has a stable calorific value.

When the large-sized material and the small-sized material are separated in this way, the dried material treated by the fermentation drying apparatus has a smaller moisture content than before the treatment, and therefore, there is an advantage that the screening is easy. It is preferable that: the dried material is divided into a relatively large-sized material, a relatively small-sized material and an intermediate-sized medium-sized material, and the small-sized material is used as the appropriate fuel.

Further, it is preferable to further include a reintroducing device for reintroducing the medium-sized material into the closed vessel in order to reuse the medium-sized material for the treatment by the fermentation drying device. In this case, the dried product which has not been sufficiently fermented and dried is easily divided into relatively large pieces, and thus is classified into medium-sized products. The medium-sized material is reprocessed in the fermentation drying apparatus, whereby the fermentation drying is further promoted to be a small-sized material. Therefore, only the small particles may be used as the fuel for the biomass burner.

In another aspect, the present invention provides a method for producing a fuel for a biomass burner using the above apparatus, comprising: a fermentation drying step of storing a treatment object containing organic waste in a closed container, heating the treatment object to a predetermined temperature range under reduced pressure while stirring, and fermenting the organic matter with a microorganism to obtain a dried product in which malodorous components are decomposed and the volume of the dried product is reduced; a classification step of classifying the dried product obtained in the fermentation and drying step into a suitable fuel suitable for combustion in a biomass burner and other fuels; and a storage step of temporarily storing at least the appropriate fuel.

In this method, as described above, the object to be treated including the organic waste can be efficiently dried, the fermentation can be promoted by the microorganism, and the small particles in the dried object thus obtained can be used as a fuel suitable for the biomass burner, for example. Further, by burning the biomass in the biomass burner, the thermal energy can be used to stably obtain the power generation energy.

Effects of the invention

According to the fuel production apparatus for a biomass burner according to the present invention, the organic waste is efficiently dried by heating under reduced pressure using the fermentation and drying apparatus, the fermentation of the organic waste is promoted by the microorganisms, and the obtained dried matter is classified, whereby, for example, the particulate matter can be used as a suitable fuel suitable for combustion in the biomass burner. Further, if the appropriate fuel is burned in the biomass burner, the heat generation energy thereof can be used to generate power stably.

Drawings

Fig. 1 is a schematic configuration diagram of the entire fuel production apparatus of a biomass burner according to an embodiment.

FIG. 2 is a schematic configuration diagram of a magnetic separator.

FIG. 3 is a schematic configuration diagram of a fermentation drying apparatus.

Fig. 4 is a schematic configuration diagram of the vibrating screen machine.

Fig. 5 is a schematic configuration diagram of the steam generating boiler.

Fig. 6 is a flowchart showing an example of the operation procedure of the fuel production apparatus of the biomass burner.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Fig. 1 is a schematic configuration diagram of an apparatus for producing biomass fuel (fuel for a biomass burner) according to an embodiment of the present invention, which is installed in, for example, an urban refuse disposal facility, and generally produces biomass fuel from refuse (waste) discharged from homes, various industries, and the like, and burns the biomass fuel in a power generation burner. Although not shown, a pit (pit) for carrying in collected garbage is provided in the garbage disposal facility.

The garbage stored in the pit is mainly general garbage, and includes various organic wastes such as kitchen garbage, paper waste, cloth, and wood, which are contained in the garbage bag and have a high water content, and incombustibles such as plastics and metals are mixed. Further, organic wastes such as feces and urine, miscellaneous domestic waste water, animal and plant residues, and sludge, which are not classified as general wastes, may be included, and coarse wastes after coarse crushing may be mixed in depending on waste disposal facilities.

The fueling device of the present embodiment includes: a crusher 1 (crushing device) for conveying the garbage in the pit by a bucket crane or the like and supplying the garbage as a treatment object; and a receiving hopper 2 into which the garbage crushed by the crusher 1 is put, and the garbage is supplied to the fermentation drying device 3 through a conveyor 21 attached to the receiving hopper 2. Further, a magnetic separator 22 for removing metals from the garbage being conveyed by the conveyor 21 is provided.

The fermentation drying apparatus 3 ferments and dries the garbage under reduced pressure as described in detail below, and the dried material treated by the fermentation drying apparatus 3 is sieved (classified) into three sizes, i.e., large, medium, and small by a vibrating screen 4 (classifying apparatus). The dried product of the "medium size" (hereinafter, also referred to as "medium-sized product") is transported by a reintroduction line 5 (reintroduction device) including a plurality of conveyors and reintroduced into the receiving hopper 2.

On the other hand, dried products of "large size" and "small size" (hereinafter also referred to as large-sized products and small-sized products, respectively) are temporarily stored in the storage device 6. The storage device 6 includes:

storage hoppers

61, 62 for temporarily storing large-sized materials and small-sized materials, respectively; and a metering and feeding device 63 for metering and feeding the small particles to the steam generating boiler 7 (heating device). Then, the high-temperature steam generated in the steam generation boiler 7 is supplied to the fermentation drying device 3.

In the present embodiment, a generator such as a steam turbine generator 91, for example, is interposed in the steam path 70 between the steam generating boiler 7 and the fermentation drying device 3, and the electric power generated by the generator is supplied to an electric power company. In addition, a part of the electric power is also used as the driving electric power of the fermentation drying apparatus 3. As the generator, a stirling engine (Sterling engine) generator or the like is also considered. The vapor path 70 will be described later.

The crusher 1 is, for example, a multi-shaft low-speed rotary crusher, and as schematically shown in fig. 1, the respective cutting blades shear the garbage by rotation of a pair of rotary shafts 10. Thus, the kitchen waste, paper dust, wood, etc. have a size suitable for fermentation and drying, and the plastic, etc. are also crushed to some extent to have a size suitable for screening. As the crusher, a single-shaft low-speed rotary crusher, a high-speed rotary crusher, a compression crusher, or the like can be used.

The magnetic separator 22 is, for example, a suspension type magnetic separator, and is suspended above the conveyor belt 21 as shown in fig. 2, and magnetic materials (indicated by black dots) such as iron pieces are attracted by magnets from the garbage conveyed by the conveyor belt 21 and are continuously discharged by a belt 22b moving between pulleys (pullies) 22 a. In addition to the suspension type, for example, a magnetic separator of a slide type, a drum (drum) type, or the like may be used, and an eddy current type magnetic separator capable of removing nonferrous metals such as an aluminum can may be used, and metal materials can be removed by using them. The magnetic separator 22 may be provided on the conveyor belt 37.

Fermentation drying apparatus

The fermentation drying apparatus 3 is a known fermentation drying apparatus described in patent document 1 and the like, and as described below, the waste to be treated is heated to a predetermined temperature range under reduced pressure while being stirred, and organic substances are fermented by microorganisms to obtain a dried product with a reduced volume.

As schematically shown in fig. 3, the fermentation drying apparatus 3 includes a cylindrical tank 30 formed in an airtight manner so as to keep the inside at atmospheric pressure or lower, as a closed container for containing the garbage supplied by the conveyor 21 as described above. A heating jacket 31 is provided on the peripheral wall of the boiler body 30, and heating steam is supplied from the steam generating boiler 7 through a steam control device 92.

Further, a stirring shaft 32 extending in the longitudinal direction (the left-right direction in fig. 3) is provided inside the can 30 surrounded by the heating jacket 31, and is rotated at a predetermined rotational speed by an electric motor 32 a. The stirring shaft 32 is provided with a plurality of stirring plates 32b spaced apart from each other in the axial direction, whereby the garbage can be stirred and can be fed in the longitudinal direction of the tank 30 after the fermentation and drying are completed. Instead of the electric motor 32a, a hydraulic motor may be used.

That is, a garbage inlet 30a supplied from the conveyor 21 is provided at an upper portion of one side (left side in fig. 3) in the longitudinal direction of the can body 30, and the garbage introduced therefrom is stirred by the rotation of the stirring shaft 32 as described above while being heated by the heating jacket 31. Then, after a predetermined time has elapsed, the liquid is discharged from the discharge portion 30b provided at the lower portion of the can body 30.

Although not shown in detail, in the present embodiment, a passage for steam is further formed inside the stirring shaft 32, and the heating steam is supplied from the steam control device 92 through the steam passage 70 here. This allows the waste to be stirred by the stirring shaft 32 while being heated from the inside. The drain water after the vapor condensation is returned to the vapor control device 92 through the vapor path 70.

A guide portion 30c for guiding steam generated from the heated waste to the condensing portion 33 is provided in a protruding manner on the upper portion of the can body 30 for heating the waste. The condensation unit 33 includes a plurality of cooling pipes 33b supported by the pair of headers 33a, and a cooling water path 80 is provided between the cooling pipes 33b and the cooling tower 8 described below.

That is, as schematically shown in fig. 3, the cooling tower 8 is provided with a water receiving tank 81 into which the cooling water discharged from the condensation unit 33 flows, a scoop pump 82 which scoops up the cooling water from the water receiving tank 81, and a nozzle 83 which sprays the scooped cooling water. While the cooling water ejected from the nozzle 83 flows down in the flow-down portion 84, the temperature of the cooling water is lowered by the air blown from the fan 85, and the cooling water flows into the water receiving tank 81 again.

The cooling water cooled in the cooling tower 8 is sent by the cooling water pump 86, returned to the condensation unit 33 through the cooling water passage 80, and while flowing through the plurality of cooling pipes 33b, the temperature of the cooling water rises due to heat exchange with the steam generated from the garbage as described above. Then, the cooling water is returned to the cooling tower 8 again by the cooling water path 80. That is, the cooling water circulates through the cooling water path 80 between the condensation unit 33 and the cooling tower 8.

In addition to the cooling water thus circulated, condensed water obtained by condensing steam generated from the heated refuse in the condensing unit 33 is injected into the cooling tower 8. That is, the condensed water generated in the condenser 33 is retained in the condenser 33 and the communication passage 35. In the present embodiment, a vacuum pump 36 is connected to the condensing unit 33 via a communication passage 35 to reduce the pressure in the tank 30.

Therefore, when the vacuum pump 36 is operated, air and condensed water are sucked out from the condensing portion 33 through the communication passage 35, and air and vapor in the tank 30 are introduced into the condensing portion 33 through the communication passage 34 and the guide portion 30 c. The condensed water is sucked out from the condenser 33 to the vacuum pump 36, and is guided from the vacuum pump 36 to the water receiving tank 81 of the cooling tower 8 through a water guide pipe.

The condensed water thus introduced into the water receiving tank 81 of the cooling tower 8 is mixed with the cooling water, pumped up by the pump 82 as described above, and sprayed from the nozzle 83, and then cooled while flowing down in the flow-down portion 84. Since the condensed water contains microorganisms similar to those added to the garbage in the tank 30 and the odor components and the like contained in the condensed water are decomposed, the odor does not escape to the outside of the tank.

Operation of the fermentation drying apparatus

When the operation of the fermentation drying apparatus 3 configured as described above is described, the garbage accommodated in the tank 30 is stirred with the rotation of the stirring shaft 32 while being heated by the heating steam supplied to the heating jacket 31 (and the steam passage such as the stirring shaft 32). The heating temperature supplied from the steam control device 92 is preferably, for example, about 140 ℃.

Thus, the temperature is efficiently raised by the heating from the outside by the heating jacket 31 surrounding the inside of the can body 30 and the heating from the inside by the stirring shaft 32 and the like, and the mixture is stirred by the stirring shaft 32. Further, since the pressure is reduced by the operation of the vacuum pump 36, the boiling point is lowered in the tank 30, the evaporation of water is advanced, and the fermentation and drying are promoted.

In the fermentation and drying step using the fermentation and drying apparatus 3, one step is preferably 2 hours, for example, and it takes 30 minutes to ferment the garbage first. When the pressure inside the can 30 is reduced to-0.06 to-0.07 MPa (gauge pressure, hereinafter gauge pressure is omitted), the temperature of the water inside the can 30 is maintained at 76 to 69 ℃ (saturated vapor temperature). As a result, the waste is mainly fermented and decomposed by the following microorganisms.

Next, the waste during the fermentation was dried for 1.5 hours. Therefore, when the pressure in the tank 30 is further reduced to-0.09 to-0.10 MPa, the temperature of the water in the tank is maintained at 46 to 42 ℃ (saturated steam temperature), and drying of the garbage is sufficiently promoted. In the case of performing such drying treatment, it is preferable that the microorganisms added to the waste in the tank body 30 are a complex effective microorganism group, which is based on a plurality of indigenous microorganisms and is cultured in advance as described in patent document 1, and which is generally called SHIMOSE 1/2/3 group as the center of the colony.

The SHIMOSE 1 is FERM BP-7504 (published collection of microorganisms at the institute of Industrial and technology, national institute of economic and Industrial science and technology (Tokyo 1-3, Botushi, Japan) (Bitsukuwa , , technical Gross, and Kitsukuwa microorganism センタ, national institute of Industrial science, , technical research (Kitsuwa つくば, Japan, 1-3), and is internationally deposited 3 months and 14 days 2003). Note that shimse 2 is FERM BP-7505 (international depository was performed in the same manner as shimse 1) and is a microorganism belonging to pichia farinosa (pichia pastoris) having salt tolerance, and shimse 3 is FERM BP-7506 (international depository was performed in the same manner as shimse 1) and is a microorganism belonging to Staphylococcus (Staphylococcus).

-vibrating screen machine

The dried product treated by the fermentation drying apparatus 3 as described above is sieved by the vibrating screen 4 and classified into three sizes, i.e., large, medium, and small. The vibrating screen 4 of the present embodiment screens the dried material into a large-sized material of, for example, 50mm or more, a small-sized material of, for example, 30mm or less, and a medium-sized material of an intermediate size between them, depending on the size of the dried material.

As shown in fig. 4, in the vibrating screen machine 4, a cylindrical casing 41 is supported on a lower table 43 in a floating manner by a plurality of (for example, 4) coil springs 42, and a lid 44 for closing an upper end opening of the casing 41 is provided with a dried material inlet 44 a. A feed hopper 45 is disposed above the inlet 44a, and dried material discharged from the tank 30 of the fermentation drying apparatus 3 is fed by a conveyor 37 (see fig. 1).

Further, inside the casing 41 into which the dried material is put, 3 metal meshes 46a to 46c are provided substantially horizontally so as to be vertically separated from each other. The mesh of the upper-stage expanded metal 46a is set to, for example, 50mm corresponding to the size of the large-sized objects, and the mesh of the middle-stage expanded metal 46b is set to, for example, 30mm corresponding to the size of the medium-sized objects.

Further, a mesh tray 47 having a large mesh is disposed below the metal meshes 46a to 46c at a predetermined interval, and a plurality of mesh rubber balls 48 are placed on the upper surface thereof at a predetermined interval. Further, 3 discharge ports 41a to 41c are provided on the outer periphery of the housing 41 so as to be vertically separated from each other so as to correspond to the upper surfaces of the three metal meshes 46a to 46c, and large, medium, and small dried products sifted by the metal meshes 46a to 46c are discharged.

Further, an inverted mortar-shaped bottom portion 49 whose inner peripheral side projects upward is disposed so as to close the lower end opening of the housing 41. The vibration motor 50 is disposed below the bottom portion 49 that closes the lower end opening of the housing 41 in this manner.

The vibration motor 50 is housed inside the peripheral wall of the cylindrical lower base 43 so as to be surrounded by the peripheral wall of the lower base 43, and is suspended from the lower end of the housing 41 via an elastic bracket 41e or the like.

Eccentric weights

50a and 50b are provided above and below the vibration motor 50, and the housing 41 is vibrated as a whole by eccentrically rotating these weights.

When the entire housing 41 is vibrated in this manner, the dried material put in through the inlet 44a of the upper lid 44 first moves to the outer peripheral side of the upper metal mesh 46a while rolling. Then, the dried material having a size of 50mm or more reaches the outer periphery of the casing 41 without passing through the meshes of the expanded metal 46a, and is discharged as large-sized material from the discharge port 41a at the upper stage to the outside of the casing 41.

On the other hand, the dried product having a size of less than 50mm falls downward through the mesh of the upper-stage expanded metal 46a, and this time moves to the outer peripheral side of the middle-stage expanded metal 46b while rolling. Then, the dried material having a size of 30mm or more reaches the outer periphery of the casing 41 without passing through the meshes of the expanded metal 46b, and is discharged as medium particles from the discharge port 41b at the middle stage to the outside of the casing 41.

The dried material having a size of less than 30mm falls downward through the mesh of the middle-stage expanded metal 46b, moves to the outer peripheral side while rolling on the lower-stage expanded metal 46c, and is discharged as small particles from the lower-stage discharge port 41c to the outside of the casing 41. The classifying device is not limited to the vibrating screen 4 described above, and may be, for example, a drum screen, a swing type classifier, a rotary type classifier, or the like.

In the dried product obtained by such screening, large particles mainly contain plastics and the like, and the heat generation thereof is large. On the other hand, the medium-sized particles and the small particles are mainly obtained by fermenting and drying organic substances, and particularly, the small particles are also promoted to be fermented, and the particle size, particle shape, and components are homogenized, so that the state of fuel supply to the biomass burner 71 and the heat energy generated by combustion thereof are stabilized.

On the other hand, since the medium particle size is not promoted in the fermentation and drying as compared with the small particle size, there is a side which is not suitable for use as the fuel of the biomass burner 71, and therefore, the medium particle size can be molded into the small particle size by feeding the medium particle size again into the fermentation and drying device 3 and fermenting and drying again.

Therefore, in the present embodiment, the large-sized particles and the small-sized particles are temporarily stored and used as fuel, while the medium-sized particles are returned to the fermentation drying apparatus 3 and subjected to the fermentation drying treatment again. That is, as described above, the medium particles discharged from the discharge port 41b at the middle stage of the vibrating screen machine 4 are conveyed by the reintroducing line 5 composed of a plurality of conveyors and are introduced into the receiving hopper 2 of the fermentation drying device 3.

On the other hand, the large and small particles discharged from the

discharge ports

41a and 41c of the upper and lower stages of the vibrating screen 4 are temporarily stored separately in the

storage hoppers

61 and 62 of the storage device 6. When the fermentation drying apparatus 3 is operated to treat the waste as described above, the small particles are measured by the screw-type measuring and supplying device 63 and supplied to the biomass burner 71 of the steam generation boiler 7 (see fig. 5).

The metering device 63 drives the screw feeder 63a by an electric motor not shown, and feeds out the particulate matter by rotation thereof. The amount of supply per unit time thus obtained changes depending on the rotation speed of the screw feeder 63a, and the amount of small particles (the amount of supply per unit time) supplied from the storage hopper 61 to the steam generation boiler 7 can be adjusted.

Steam generating boiler

The steam generation boiler 7 that generates high-temperature steam by burning the small particles as described above includes, as schematically shown in fig. 5: a biomass burner 71 capable of efficiently burning the dried material; and a steam generating unit 72 for generating high-temperature steam by heating a heat medium such as water with the heat of combustion. The heating steam generated in the steam generating unit 72 is supplied to the fermentation drying device 3 (the heating jacket 31 of the tank 30, etc.) via the steam control device 92 of the steam passage 70.

The biomass burner 71 as an example includes: a hopper 73 into which the small particles as the fuel and the auxiliary fuel are charged; a screw feeder 74 driven by an electric motor 74a to feed out the small particles and the like fed from the hopper 73; 1-time combustion furnace 75 for generating a combustible gas by thermally decomposing the small particles or the like thus fed; and 2 burners 76 for completely burning the combustible gas.

The screw feeder 74 is housed in a cylindrical chamber 74b, and then the hopper 73 is connected to the upper end side (right side in fig. 5). A rotary valve 73a is provided at the lower portion of the hopper 73. On the other hand, the front end portion (left end portion in fig. 5) of the screw feeder 74 faces the opening of the upstream end (right end portion in fig. 5) of the cylindrical 1-time combustion furnace 75, and supplies the particulate matter and the like thereto.

An electrically-heated ignition plug 75a is provided to face the opening at the upstream end of the 1 st-time combustion furnace 75, and when the biomass burner 71 starts operating, the small particles and the auxiliary fuel in the 1 st-time combustion furnace 75 are ignited. The 1 st combustion furnace 75 is supplied with the particulate matter from the screw feeder 74, and the air forced by the fan 77 flows into the chamber 74b to burn the particulate matter and the like.

In addition to the inflow of air from the opening at the upstream end, air is also introduced into the 1 st combustion furnace 75 through the plurality of holes provided in the peripheral wall thereof, and the amount of the air tends to be insufficient for the combustion of the particulate matter and the like, so that the particulate matter is partially combusted in the 1 st combustion furnace 75, but the remaining particulate matter is thermally decomposed at a high temperature to generate combustible gas. The combustible gas thus generated flows out to the downstream 2-time burner 76 while being burned.

That is, a nozzle section 75b whose tip is narrowed is provided at the downstream end (left end in fig. 5) of the 1-time burner 75 so as to project into the 2-time burner 76, and the combustible gas is burned while being injected into the 2-time burner 76 from the nozzle section 75 b. The high-temperature combustible gas thus injected is mixed with 2-time air taken in from the air intake passage 76b and burned in the burner portion 76a provided in the 2-time burner 76, and the flame is ejected into the downstream combustion chamber 76 c.

The flame is entrained in the air in the combustion chamber 76c and burned so that unburned components are substantially eliminated, and the high-temperature combustion gas (i.e., combustion gas) generated thereby passes through the steam generation unit 72, and is released into the atmosphere after passing through the exhaust pipe 78 on the downstream side thereof, a dust collecting device (not shown), and the like. Since the combustible gas generated from the small particles is burned in this manner, the exhaust gas contains less harmful substances and can be purified by a general dust collector.

The steam generating unit 72 has a general structure, details of which are omitted, and a pipe 72a is provided spirally (or zigzag in the combustion chamber 76 c) so as to surround the combustion chamber 76c of the 2-time combustion furnace 76 from which the flame is jetted, and the steam or water flowing through the inside is heated by the flame or combustion gas of the combustion chamber 76c to generate high-temperature steam. The pipe 72a is connected to the steam turbine generator 91 and the steam control device 92 via the steam path 70.

That is, the steam generating unit 72 heats water to generate power generation steam by the combustion heat energy of the fuel as described above. In the present embodiment, as described above, the power generation steam generated in the steam generation unit 72 of the steam generation boiler 7 is supplied to the steam turbine generator 91, and thereby the electric power is supplied to the electric power company.

Further, the heating steam is supplied to the fermentation drying apparatus 3 (the heating jacket 31 of the can body 30, etc.) via the steam control device 92, and the interior of the can body 30 is heated as described above with reference to fig. 3. Thus, the drain water after the condensation of the steam is discharged from the heating jacket 31 or the like, flows through the steam passage 70, and returns to the steam generation unit 72.

Next, when the steps of producing the biomass fuel using the above-described production apparatus are described, as an example shown in the flowchart of fig. 6, first, in the pretreatment step (step S1), the refuse stored in the pit is charged into the crusher 1, crushed to a predetermined size, and then charged into the receiving hopper 2. Then, the iron pieces and the like contained in the garbage are removed by the magnetic separator 22 while being conveyed by the conveyor belt 21.

Next, in step S2, the lid of the inlet 30a of the tank 30 of the fermentation drying device 3 is opened, and the garbage conveyed by the conveyor 21 is loaded. At this time, the inside of the can 30 becomes atmospheric pressure, and then the lid of the inlet 30a is closed.

In step S3, as described above with reference to fig. 3, the interior of the can body 30 is heated under reduced pressure to promote fermentation and drying of the garbage contained therein (fermentation and drying step). That is, the heating steam is supplied from the steam control device 92 to heat the inside of the can 30. At the same time, the stirring shaft 32 is rotated at a predetermined rotation speed (for example, about 8 rpm). Further, when the pressure inside the tank 30 is reduced by the operation of the vacuum pump 36, the boiling point of the water inside the tank 30 is lowered, and the evaporation of the water is advanced at the activity temperature of the microorganisms, thereby promoting the fermentation and drying of the garbage.

If a predetermined time (for example, about 2 hours) has elapsed while maintaining the temperature and pressure in the tank 30 in this manner, the vacuum pump 36 and the stirring shaft 32 are temporarily stopped. At this time, the dried product was reduced in volume. Then, it is determined in step S4 whether or not the fermentation drying process is repeated a predetermined number of times, and if it is determined Negatively (NO), the process returns to step S2.

By thus charging the waste and the microorganisms into the tank 30 and repeating the fermentation and drying steps a predetermined number of times, a large amount of waste can be sufficiently fermented and dried. If the answer in step S4 is YES, the process proceeds to step S5, in which the operation of the vacuum pump 36 and the steam generation boiler 7 is stopped, and the stirring shaft 32 is rotated in the reverse direction, the lid of the discharge unit 30b is opened, and the dried product is discharged from the tank 30 (atmospheric pressure (discharge)).

By fermenting and drying the mixture and reducing the volume as described above, the dried product becomes a material suitable for screening, and the material is conveyed by the conveyor 37 and fed from the feed hopper 45 into the vibrating screen 4. Then, by the operation of the vibrating screen 4, as described above with reference to fig. 4, the dried material is separated into large, medium and small dried materials (classification step: step S6), and the medium particle materials are reintroduced into the receiving hopper 2 through the reintroducing line 5 (medium particle conveyance: step S7).

Meanwhile, the large particles and the small particles are temporarily stored in the

storage hoppers

61 and 62, respectively (storage step: steps S8 and S9). Since the large particles temporarily stored in this way contain plastics and the like, they are supplied to, for example, a combustion furnace for high-output plastics (step S10). On the other hand, the small particles are burned in the next process using the fermentation drying device 3, and are thus supplied to the biomass burner 71 of the steam generation boiler 7 (step S11).

Step S3 of the above-described flow corresponds to the following fermentation and drying step: the garbage to be treated is stored in the tank 30, heated to a predetermined temperature range under reduced pressure while stirring, and the organic matter is fermented by microorganisms to obtain a dried product with reduced volume. In this step, the inside of the can body 30 is heated by the combustion heat of the dried product (particulate matter) obtained by the previous process.

Step S6 of the above flow corresponds to the following classification step: the dried matter obtained in the fermentation drying step is classified into a relatively small-sized matter (suitable fuel suitable for combustion in the biomass burner 71) and a relatively large-sized matter (other fuel), and step S9 corresponds to a storage step of temporarily storing at least the small-sized matter.

Therefore, according to the apparatus for producing biomass fuel by fermentation drying according to the present embodiment, by using the known fermentation drying apparatus 3, the tank 30 in which the waste containing organic substances is stored is depressurized to lower the boiling point of water, so that the water can be efficiently evaporated at a relatively low temperature to promote drying. By lowering the temperature in this manner, microorganisms can be activated to promote fermentation of organic substances.

Further, as the dry matter to be burned in the steam generation boiler 7, only the small-sized matter, which is homogenized in particle size, particle shape, and components, among the large-sized matter, the medium-sized matter, and the small-sized matter obtained by the sieving with the vibrating sieve machine 4 is used, and the unstable medium-sized matter, which is homogenized in particle size, particle shape, and components, is not burned. This can stabilize combustion in the biomass burner 71 of the steam generation boiler 7.

Further, in the present embodiment, since the crusher 1 crushes the garbage to be treated before the garbage is put into the tank 30 of the fermentation drying device 3 to increase the surface area of the treated material, the water can be evaporated more efficiently in the tank 30 as described above, the drying can be further promoted, and the fermentation of the organic matter can be further promoted.

The embodiments disclosed herein are illustrative in all respects and are not to be construed as limiting. The technical scope of the present invention is defined not by the embodiments described above but by the claims. The technical scope of the present invention includes all modifications within the meaning and scope equivalent to the claims.

For example, in the above embodiment, the dried material treated in the fermentation drying device 3 is sieved into three sizes of large, medium and small, and the large-sized material and the small-sized material are temporarily stored, and then only the small-sized material is supplied to the steam generation boiler 7 and burned in the biomass burner 71, while the medium waste is reprocessed by the fermentation drying device 3, but the present invention is not limited thereto, and the medium waste may be used for the production of fertilizers and feeds without being reprocessed.

Alternatively, the dried refuse may be divided into two sizes, i.e., large and small, instead of three sizes, i.e., large, medium and small, and after temporarily storing the two sizes, only the small particles may be supplied to the steam generation boiler 7.

Further, in the above-described embodiment, high-temperature steam is supplied from the steam generation boiler 7 in order to heat the inside of the boiler body 30, but the steam heating is not limited to the heating by steam, and an electric heater may be used. Further, it is not necessary to crush the garbage by the crusher 1 before charging into the fermentation drying device 3 as in the above-described embodiment, and it is not necessary to remove metals by the magnetic separator 22. For example, the waste may be crushed and dried or the metal may be removed after the treatment by the fermentation drying apparatus 3.

The application claims priority based on Japanese patent application No. 2017-179295 filed in Japan on 19.9.2017. The priority is hereby incorporated by reference in its entirety into the present application.

Industrial applicability

The present invention has industrial applicability in that, when waste is heated under reduced pressure using a fermentation drying apparatus and is fermented by microorganisms, fuel costs for heating can be reduced.

Description of the reference numerals

1 crusher (crushing device)

3 fermentation drying device

30 tank (closed container)

4 vibrating screen machine (grading plant)

5 throw-in circuit (throw-in device)

6 storage device

61, 62 storage hopper

7 steam generating boiler (heating device)

Claims

1. A fuel production device for a biomass burner, comprising:

a fermentation drying device which contains a treatment object containing organic waste in a closed container, heats the treatment object to a predetermined temperature range under reduced pressure while stirring, and ferments organic substances with microorganisms to obtain a dry object with reduced volume by decomposing malodorous components;

a classifying device for classifying the dried material obtained by the fermentation drying device into a suitable fuel suitable for combustion in a biomass burner and a fuel other than the suitable fuel; and

a storage device that temporarily stores at least the suitable fuel,

the classification device is configured to: separating the dried material into relatively large, small and intermediate sized, medium sized particles, and using the small particles as the suitable fuel,

the fuel manufacturing apparatus of the biomass burner is provided with a re-charging device for re-charging the medium-sized material into the closed container in order to re-treat the medium-sized material with the fermentation drying device,

the fuel production apparatus for a biomass burner includes a supply device capable of changing the supply amount of the particulate matter from the storage device to the biomass burner, and the generated heat energy can be adjusted.

2. The fuel production device for a biomass burner according to claim 1, comprising:

and a heating device for burning only the small particles in the biomass burner and heating the organic waste contained in the closed container by using a part of the generated heat energy.

3. A method for producing a fuel for a biomass burner, using the apparatus for producing a fuel for a biomass burner according to claim 1, comprising:

a fermentation drying step of storing a treatment object containing organic waste in a closed container, heating the treatment object to a predetermined temperature range under reduced pressure while stirring, and fermenting the organic matter with a microorganism to obtain a dried product in which malodorous components are decomposed and the volume of the dried product is reduced;

a classification step of classifying the dried product obtained in the fermentation and drying step into a suitable fuel suitable for combustion in a biomass burner and other fuels; and

a storage step of temporarily storing at least the appropriate fuel.