IES67370B2

IES67370B2 - A manufacturing process

Info

Publication number: IES67370B2
Authority: IE
Inventors: Peter Ward
Original assignee: Stoneware Tech Ltd
Priority date: 1996-01-19
Filing date: 1996-01-19
Publication date: 1996-03-20
Also published as: GB2309499B; IES960045A2; GB2309499A; GB9601339D0

Abstract

Shale is broken in a crusher (11) and delivered to a box feeder (12) then discharged to a pan mill (18) in which the size of shale pieces is reduced prior to delivery between high-speed rollers (26) for final size reduction. Downstream of the rollers (26) a feeder (30) delivers the shale pieces to a mixer (34) in which water is added to form a shale paste which is passed through an extruder (50,51) at which tubular pipe sections are extruded, stacked on pallets and delivered to a drying room (70). Heated air extracted from a kiln (75) after firing is passed through the drying room (70) to reduce the moisture content of the pipe sections. Then the dried pipe sections are delivered to a kiln (75) and fired. The extruder (50) produces straight sections with lower flanges by means of an associated flange former below the die. Alternatively, the extruder (51) produces bend sections along with the flange former. The sections are trimmed by a cutter wire.

Description

- 1 A Manufacturing Process Γ This invention relates to a manufacturing process and apparatus, in particular for manufacturing ceramic pipes. L The invention particularly relates to a process and apparatus for manufacturing ceramic pipes in an efficient and trouble-free manner.

According to the invention there is provided a manufacturing process for ceramic pipes comprising the steps : delivering shale to a crusher, crushing the shale into 10 pieces and conveying the broken shale pieces to a feeder, discharging the broken shale pieces from the feeder at a pre-desired rate, delivering the broken shale pieces to a pan mill having 15 a tray for receiving the broken shale pieces, circulating rollers around the tray for crushing the shale pieces through discharge slots in the tray for reducing the size of the shale pieces, feeding the crushed shale pieces in a controlled manner 20 between a pair of high-speed rollers for further reducing the shale pieces to a pre-desired maximum size, e delivering the shale pieces to a mixer, 507370 - 2 adding water to the shale in the mixer and mixing the water and shale to form a shale paste having a desired water content, delivering the shale paste to an extruder, forcing the shale paste through a die at an outlet of the extruder into a flange former for forming a flange of a desired shape, retracting the flange former, continuing extruding the shale paste through the die for forming a tubular pipe section with a flange at a lower end of the pipe section, parting the pipe section from the extruder, cutting the pipe section to a desired size, delivering the pipe sections to a drying room, closing the drying room and circulating heated air through the drying room for reducing the moisture content of the pipe sections to a pre-set desirable maximum value, the heated air being delivered to the drying room from a kiln after firing of the kiln has been completed, conveying the dried pipe sections to a kiln, sealing the kiln and firing the kiln, after firing removing the pipe sections from the kiln.

In one embodiment of the invention the process includes alternating feeding of the shale pieces between a central portion of the high-speed rollers and outer ends of the rollers. - 3 In another embodiment the process includes extruding the shale paste through a bore and between the bore and a die centrally mounted at an outlet end of the bore, the shale paste being forced past a baffle plate mounted spaced inwardly of the bore outlet for blocking portion of one side of the bore for biasing shale paste feed to the opposite side of the bore thus extruding a curved pipe section at the outlet end of the bore.

In a preferred embodiment the process includes mounting the curved pipe section on a pedestal, a flanged end of the curved pipe section being seated on the pedestal, advancing a cutter wire into a free upper end of the curved pipe section, and rotating the cutter wire for parting away an upper end of the curved pipe section.

In a particularly preferred embodiment the process includes feeding the heated air from the kiln to a distribution manifold beneath the floor of the drying room and discharging the heated air up through a slatted floor of the drying room for drying the pipe sections.

Conveniently the process includes the step of conveying the broken shale from the feeder to the pan mill, passing the broken shale beneath a magnetic plate extending above the conveyor upstream of the pan mill.

In a further embodiment the process includes delivering shale pieces discharged from the high-speed rollers to a mixer feeder, the mixer feeder having a hopper for reception of the shale pieces with discharge screws at an outlet of the hopper for discharging the shale pieces from the hopper, controlling the speed of the discharge screws for regulating discharging of shale pieces from the hopper to the mixer. - 4 In another embodiment the process includes forcing the shale paste through a plurality of holes in a discharge plate of the mixer for forming the shale paste into pellets of shale paste at an outlet of the mixer.

In another embodiment the process includes the step of inserting a clay spacer between each lowermost pipe section and an upper surface of a pallet when stacking the pipe sections on the pallet prior to drying.

In another aspect the invention provides apparatus for carrying out the process of the invention as herein described.

The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which; Fig. 1 is a schematic illustration of a pipe manufacturing process according to the invention; Fig. 2 is a diagrammatic perspective view of high speed rollers used in the process; Fig. 3 is a plan view of the rollers; Fig. 4 is a perspective view of a mixer used in the process; Fig. 5 is an elevational view of a pipe forming station used in the process; Fig. 6 is a perspective view of a drying room used in the process; Fig. 7 is an elevational view of a pipe bend former used in the process; Fig. 8 is a cut-away perspective view showing portion of the pipe bend former; Fig. 9 is a sectional view along the line IX - IX of Fig. 8; and Fig. 10 is a perspective view of a pipe bend cutter used in the process.

Referring to the drawings, a process and apparatus for manufacturing ceramic pipes according to the invention will be described.

Shale is delivered from a shale pit 10 to a crusher 11 and fed through an associated pair of contra-rotating crushing rollers to break up the shale. The broken shale is delivered downstream to a box feeder 12. The shale is discharged from an outlet 14 of the box feeder 12 at a desired rate and is delivered on a conveyor 15 under a magnetic plate 16 which removes any iron or steel particles entrained in the shale.

The shale is then delivered into a pan mill 18 having a tray 19 over which a pair of rollers 20 circulate, the rollers 20 being mounted on a rotating carrier arm 21. The rollers 20 press the shale down through slots in the tray 19 of the pan mill 18 reducing the size of shale pieces to 6mm maximum, the pieces dropping onto a conveyor 24 which delivers the shale to high speed rollers 26. If desired water may be added to the shale in the pan mill.

Shale is delivered between an associated pair of high speed rollers 26 for reduction of the shale particles to 0.6mm (0.025 inch) size maximum. It will be noted from Figs. 2 and 3 that a spreader bar 28 is positioned above the high speed rollers 26 and is movable between a lowered position as shown in Fig. 2 and a raised inoperative position as shown in broken outline in Fig. 2. In the lowered position the bar 28 deflects the shale outwardly to outside edges of the rollers 26. With the bar 28 in the raised inoperative position the shale will tend to feed into the centre portion of the rollers 26. By engagement and disengagement of the bar 28 on successive days this ensures an even wearing of the surface of the rollers 26 which advantageously gives more accurate crushing of the shale and also reduces the need for periodic dressing and resurfacing of the rollers 26.

The shale discharged from the rollers 26 is conveyed to a feeder 30 which comprises a hopper with discharge screws at an outlet of the hopper for discharging the shale at a desired rate from the hopper. The speed of the screws is adjustable for controlling the discharge rate.

Operation of the various machines is regulated by a controller which is operable to regulate the speeds of the various machines to achieve a smooth flow of shale material at a desired rate to the feeder.

Downstream of the feeder 30 the shale is delivered by a conveyor 32 into a mixer 34. The mixer 34 comprises a container 35 within which a pair of juxtaposed mixing paddles 36 are rotably mounted for mixing the shale with water delivered through a spray head 38 into the mixer 34. As the paddles 36 mix the shale and water they advance the mixture to an outlet end 39 of the mixer 34 formed by a plate having a plurality of through holes 40 through which the shale mixture is delivered to form pellets which drop on to a conveyor 42.

Downstream of the mixer 34 the shale pellets are selectively delivered either to a straight pipe former 50 or a pipe bend former 51.

At the straight pipe former 50 (see Fig. 5) the shale pellets pass through a de-aerator 52 in which they are passed through a sieve within a housing to which a vacuum is applied to remove air released as the pellets are delivered by a screw through the sieve. Shale paste is then extruded through a die 58 to form a pipe section 60 having a tubular body 61 with a flange 62 at one end. A flange former 63 is positioned below the die. The flange former 63 is carried on a vertically movable support rod 64. Shale paste is extruded into the former 63 to form a flange 62 of a desired shape. Then the flange former 63 is lowered while at the same time the shale paste is extruded from the die to form the tubular body 61 of the pipe section 60. When a pre-set length of pipe section has been extruded a cutter wire moves across an outlet of the die to part the pipe section 60 from the die 58.

At a trimming station 65 each pipe section 60 is cut to size and then lifted by means of an overhead hoist 54 with a vacuum clamp 55 for gripping a side of the pipe section 60 and stacked on pallets 66. It will be noted that the lowermost pipe sections 60 are mounted on spacer rings 67 (which are off cuts from the trimming station 65) on the pallets 66. It will appreciated that the vacuum clamp 55 facilitates handling without damage to the pipe sections 60.

Pallets 66 of the pipe sections 60 are transported to drying rooms 70 (Fig. 6). Each drying room 70 has a slatted floor 71. Hot gases from kilns 75 are delivered through pipes for discharge up through the slots 72 in the floor 71 for drying the pipe sections 60 on the pallets within the drying room 70. Within the drying room 70 the moisture content of the pipe sections 60 is reduced to a maximum of 1.5%. It will be appreciated that waste heat from the kilns is used to dry pipe section prior to firing thus minimising production costs and improving the overall efficiency of the process.

After drying the pallets 66 of pipe sections 60 are transported to a kiln 75 and the pipe sections 60 are stacked within the kiln 75 which is closed and fired. After firing the hot gases within the kiln 75 are bled off through the drying room 70 for drying further batches of pipe sections 60 and then the kiln 75 is opened and the fired pipe sections removed and palletised.

Referring to Figs. 7 to 9 the pipe bend former 51 is shown. The pipe bend former 51 has a housing 80 with an interior bore 81 through which shale paste is driven by a screw 82. At an outlet end 84 of the bore 81 a die head 85 is centrally mounted within the bore 81. The die head 85 has a bell-shape and defines with a side wall of the bore 81 an annular outlet 86 through which shale is extruded to form a curved pipe section 87.

In order that the pipe section 87 is curved as it is fed from the housing 80 a baffle plate 89 is mounted within the bore 81 above the die head 85. Advantageously the baffle plate 89 ensures that more material is fed to one side of the die head 85 which thus extrudes the pipe section 87 in a curved shape. When the required length of pipe has been extruded a cutter wire passes through the pipe to part the pipe section 87 from the pipe bend former 51. - 9 A flange former 90 mounted on an associated vertically movable carrier rod 91 is positioned below the housing 80. After initially extruding shale paste into the flange former 90 forming a pipe flange 92 the flange former 90 is lowered and then a curved tubular body 93 of the curved pipe section 87 is extruded and subsequently cut away at the required length.

The curved pipe section 87 is then mounted on a pipe bend cutter 100 (Fig. 10). The pipe bend cutter 100 has a base frame 101 with a pedestal 102 on which the curved pipe section 87 is mounted the flange 92 seating on the pedestal 102 by a U-shaped support 105. A cutter wire 104 is rotably mounted on a carrier plate 106 and is rotatable on the carrier plate 106 by means of a motor 107. The carrier plate 106 is hingedly mounted at an inner end 108 on the frame 101. A free end 109 of the carrier plate 106 is connected by means of a ram 110 to the frame 101 for raising and lowering the carrier plate 106 on the frame 101. When a curved pipe section 87 is mounted on the pedestal 102 the ram 110 is operated to engage the cutter 104 with the upper end of the curved pipe section 87. When engaged the motor 107 is operated to rotate the cutter 104 through 180° cutting away an upper end of the curved pipe section 87 leaving the desired angled face at the upper free end of the curved pipe section 87. Advantageously the cutter 104 imparts a desired angled face to the curved pipe section 87 accurately and without distorting the still malleable curved pipe section 87.

The invention is not limited to the embodiments hereinbefore described which may be varied in both construction and detail.

Claims

1. A manufacturing process for ceramic pipes comprising the steps; delivering shale to a crusher, crushing the 5 shale into pieces and conveying the broken shale pieces to a feeder, discharging the broken shale pieces from the feeder at a pre-desired rate, delivering the broken shale pieces to a pan 10 mill having a tray for receiving the broken shale pieces, circulating rollers around the tray for crushing the shale pieces through discharge slots in the tray for reducing the sise of 15 the shale pieces, feeding the crushed shale pieces in a controlled manner between a pair of highspeed rollers for further reducing the shale pieces to a pre-desired maximum sise, 20 delivering the shale pieces to a mixer, adding water to the shale in the mixer and mixing the water and shale to form a shale paste having a desired water content, delivering the shale paste to an extruder, 25 forcing the shale paste through a die at an outlet of the extruder into a flange former for forming a flange of a desired shape, retracting the flange former, continuing extruding the shale paste through the die for forming a tubular pipe section with a flange at a lower end of the pipe section, parting the pipe section from the extruder, cutting the pipe section to a desired size, delivering the pipe sections to a drying room, closing the drying room and circulating heated air through the drying room for reducing the moisture content of the pipe sections to a pre-set desirable maximum value, the heated air being delivered to the drying room from a kiln after firing of the kiln has been completed, conveying the dried pipe sections to a kiln, sealing the kiln and firing the kiln, after firing removing the pipe sections from the kiln. A process as claimed in claim 1, which includes alternating feeding of the shale pieces between a central portion of the high-speed rollers and outer ends of the rollers and preferably the process includes feeding the heated air from the kiln to a distribution manifold beneath the floor of the drying room and discharging the heated air up through a slatted floor of the drying room for drying the pipe sections and preferably the process includes delivering shale pieces discharged from the high-speed rollers to a mixer feeder, the mixer feeder having a hopper for reception of the shale pieces with discharge screws at an outlet of the hopper for discharging the shale pieces from the hopper, controlling the speed of the discharge screws for regulating discharge of shale pieces from the hopper to the mixer, and preferably the process includes forcing the shale paste through a plurality of holes in a discharge plate of the mixer for forming the shale paste into pellets of shale paste at an outlet of the mixer. A process as claimed in claim 1 or 2, which includes extruding the shale paste through a bore and between the bore and a die centrally mounted at an outlet end of the bore, the shale paste being forced past a baffle plate mounted spaced inwardly of the bore outlet for blocking a portion of one side of the bore for biasing shale paste feed to the opposite side of the bore thus extruding a curved pipe section at the outlet end of the bore and preferably the process includes mounting the curved pipe section on a pedestal, a flanged end of the curved pipe section being seated on the pedestal, advancing a cutter wire into a free upper end of the curved pipe section, and rotating the cutter wire for parting away an upper end of the curved pipe section. A pipe manufacturing process substantially as hereinbefore described with reference to the accompanying drawings . A ceramic pipe whenever produced according to the process as claimed in any preceding claim.