GB1561128A

GB1561128A - Carbonising apparatus

Info

Publication number: GB1561128A
Application number: GB53367/75A
Authority: GB
Original assignee: Aldred & Co Ltd Shirley; REDLER CONVEYERS Ltd
Current assignee: Aldred & Co Ltd Shirley; REDLER CONVEYERS Ltd
Priority date: 1975-12-31
Filing date: 1975-12-31
Publication date: 1980-02-13
Also published as: BE850046A; FR2337192A1; LU76486A1; DE2659632A1; FR2337192B1

Description

(54) CARBONIZING APPARATUS (71) We, REDLER CONVEYORS LI MITED, a British Company of Dudbridge Works, Stroud, Gloucestershire GL5 3EY and SHIRLEY ALDRED & CO. LI MITED, a British Company of Worksop, Nottinghamshire, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: This invention relates to apparatus for carbonizing vegetable waste material to provide for example an apparatus suitable for producing charcoal and its by-products from materials not readily processed into charcoal by known apparatus, such material including, inter-alia sawdust, wood chips; bagasse; and coffee bean husk.These materials are waste from other processes and are available in large quantities, some of which are renewable annually as waste from the annual produce of plants. Charcoal is a valuable source of fuel which may be processed to obtain particular qualities in order that it may be used for otter purposes.

According to the present invention we provide apparatus for carbonizing vegetable waste material, which apparatus comprises a tubular carbonizing chamber adapted to receive a fluid heating medium; conveying means conveying said waste material through said tubular carbonizing chamber and means for maintaining the material in fluid tight relationship in respect of said fluid heating medium and thereby isolated with respect to said medium yet surrounded thereby in a plane normal to the throughput of said conveying means to heat said waste material by indirect heat exchange as said waste material passes through said tubular carbonizing chamber.

The conveying means may pass the material along two paths in said chamber. In a preferred arrangement, the paths are disposed parallel and one above the other in the operative position of the apparatus.

Preferably, said paths comprise conduits which are interconnected by a connecting space for transferring material from the upper conduit to the lower conduit during operation of said conveyor means. The tubular member may include means allowing a sample of material to be taken from the lower path in the chamber.

The apparatus may include manifolds allowing the introduction and exhaust of the fluid heating medium to and from, respectively, the interior of the chamber. Preferably, a respective said manifold is disposed on said tubular member at each end of said chamber.

The apparatus may include volumetric measuring means to enable a correct load of material to be charged onto and to be moved by said conveyor means through said chamber, said measuring means with a charge of waste material restricting the ingress of the atmosphere to said chamber.

Desirably, the apparatus includes an exhaust port for gas generated in said conduits during carbonisation of the material.

The conveying means may comprise an endless conveyor having a path extending along each said conduit. The apparatus may include drive transmission means for transmitting driving motion to said endless conveyor. Conveniently, the apparatus may include means for varying the speed of said conveyor as it travels along said paths. The variable speed means may be responsive to a signal indicative of a physical condition, such as temperature, in said chamber.

The invention will now be described by way of example with reference to the single figure of the accompanying drawing which is a side elevation broken for case of illustration and partly in section, of apparatus of the invention.

Referring now to the single figure of the drawing, apparatus shown generally at 1 for carbonising vegetable waste material is seen to comprise an elongate housing showing generally at 2 disposed horizontally in the operative position of the apparatus 1. The housing 2, supported by longitudinally spaced and erect ground mounted supports 102, accommodates an endless conveyor chain 3 carrying a plurality of flight elements (not shown) for engaging the material. The housing 2 is arranged to extend between a drive end 4 and a trailing end 5, the drive end 4 houses a sprocket wheel 6 for driving the conveyor chain 3 about idler wheels 7 and 8 in the drive and trailing ends respectively. The sprocket wheel 6 is in drivable connection with a drive transmission means 106 connected to a drive means (not shown).

The apparatus includes a hollow intermediate section 9 intermediate the drive end 4 and the trailing end 5, the intermediate section 9 comprising an upper conveyor conduit 10 in parallel relation to, and spaced from, a lower conveyor conduit 11. Each of the conveyor conduits 10 and 11 defines a path which accommodates a respective one of the two substantially horizontal portions of the conveyor chain 3 as it travels within the housing 2. In the figure, the conveyor chain 3 travels in a clockwise direction.

The upper conveyor conduit 10 and the lower conveyor conduit 11 each open into a connecting space 12 at the trailing end portion of the intermediate section 9 and accommodating that end portion of the conveyor 3. Thus, the space 12 allows material to fall by gravity and/or to transfer from the upper run of the conveyor chain to the lower run during operation of the conveyor.

Adjacent the drive end 4, the upper conduit 10 communicates with an upstanding feed chute 13 through which vergetable waste material is supplied to the apparatus for carbonizing. The underside of the housing 2, intermediate the feed chute 13 and the driving end 4i is provided with an aperture defining an outlet 14 for the material when it has been carbonized and transported back to the driving end by the conveyor; it will be understood that the carbonized material falls out of the apparatus as it is passed over the open outlet 14. A rotary seal (not shown , or similar device, is fitted downstream of the outlet 14 to prevent ingress of air to the conveyor conduits 10 and 11.

The intermediate section 9 extends longitudinally through a longitudinal tubular member 15 that completely surround the conveyor 3 in a plane normal to the throughput of said conveyor along its line from left to right in the conduit 10 and right to left in the conduit 11 disposed intermediate the feed chute 13 and the trailing end 5; thus, the conduits 10 and 11 extend through the longitudinal tubular member 15. A first end of the tubular member 15 adjacent the feed chute 13 carries an annular heating fluid inlet manifold 16 in fluid-tight relationship with the intermediate section 9, whilst the other or second end of the tubular member 15 carries an annular heating fluid outlet manifold 17 in fluid-tight relationship with the intermediate section 9.It will be understood that the conduits 10 and 11 are in fluid-tight relationship with, yet isolated from both the tubular member 15 and the manifolds 16 and 17. The tubular member 15 together with the heating fluid manifolds 16 and 17 define a tubular carbonizing chamber forming a tubular path in the space between the tubular member 15 and the conduits 10 and 11 through which a heating medium can pass to effect carbonization of the material in the conduits 10 and 11.

The housing 2 is fitted with an exhaust port 18 communicating the connecting space 12 with an outlet pipe 19. The outlet pipe 19 is connected to a furnace (not shown) where gas exhausting from the interior of the housing 2 is burnt. Alternatively, the exhaust gas is passed to a separation system whereby by-products of the gas are recovered and non-condensible gases are passed to the furnace.

Explosion relief panels (not shown) are provided at suitable locations in the apparatus.

The chamber may include means, for example, a gas outlet valve (not shown), to maintain an internal chamber pressure over atmospheric pressure.

The apparatus includes volumetric measuring means comprising a pair of spaced baffle plates 113 of unequal length extending downwardly from the chute 13 and into the upper conduit 10: the baffle plate towards the drive end 4 is longer than the other baffle plate. The volumetric measuring means are provided to enable a correct load of material to be moved by the conveyor chain 3 as it travels round its endless path. Thus, maintenance of a full supply of feed material in the chute 13, in conjunction with the volumetric measuring means, ensures that the ingress of atmosphere into the chamber is minimised.

The apparatus includes a rotary valve member 114 extending through the tubular member 15 and into the lower conduit 11 to permit a sample of material to be taken from the lower conduit 11 during operation of the apparatus.

The apparatus includes inspection doors and thermometer pockets 115 each located at intervals along the tubular member 15.

Each pocket accommodates a thermometer indicating the temperature within the carbonising chamber at that location.

In operation, a heating fluid, such as heated gas, is supplied to the manifold 16 so as to pass through the space defined between the tubular member 15 and the intermediate section 9 to provide muffle heating to the conduits 10 and 11, the gas exhausing through the manifold 17. Vegetable waste material is supplied to the feed chute 13. The space between the lower end of the baffles 113 and above the conveyor chain 3 is such as to provide a required volumetric measure, or quantity, of material in the housing 2 for collection by the conveyor chain 3 as it rotates.The conveyor chain 3 rotates in a clockwise direction as shown in the drawing so as to pass the material along the upper conduit 10 and into the carbonising chamber 15, 16, 17 until each portion of material arrives in the connecting space 12, clear of the upper conduit 10, where it drops through the conveyor chain onto the conveyor and/or is carried from the upper run of the conveyor to the lower run by the conveyor chain to be transported by the conveyor chain 3 along the lower conduit 11 towards the outlet 14.

During passage of the material along the lower conduit 11, samples may be taken as required through the valve member 114.

The vegetable waste material is heated by indirect heat exchange and on completion of carbonisation, the material is released, by gravity, from the apparatus through the outlet 14 for disposal elsewhere. Any gases generated in the upper conduit 10 and/or the lower conduit 11 are exhausted from the connecting space 12 through exhaust port 18 to the gas outlet pipe 19 for disposal in the furnace. Heating fluid which is exhausted through the manifold 17 is reheated for subsequent use, or exhausted. It will be understood that the furnace is used to provide the heating fluid used for the carbonization.

In order to maintain the quality of the final product i.e. charcoal, the apparatus includes means (not shown) for varying the speed of the conveyor within the housing 2, such means being responsive to signals indicative of temperature within the carbonization chamber and generated by the thermometers; signals indicative of other information can be emitted by suitable equipment to ensure optimum efficiency of the apparatus.

It will be understood that the movement of material through the upper conduit of the apparatus, the direction of flow of gas produced or generated in the intermediate section, and the flow of heating fluid within the tubular member is all in the same direction thereby minimising the condensation of condensible gases within the upper conduit 10. Further, the temperature at the end of the carbonising chamber with respect to each conduit is maintained above the dew point odf the gases generated within the upper and lower conduits. It will be understood that in the lower conduit, the movement of the material being processed is towards the outlet 14.

Further, it will be understood that retention of heat released during the exothermal reaction that takes place during carbonization, within the chamber, minimizes the heat required from the heating fluid passing through the tubular member 15 thereby obtaining maximum thermal efficiency. If the gas being burnt in the furnace (not shown) produces heat surplus to required ments of the apparatus, such surplus heat may be used in a waste heat application such as a boiler.

Although it is preferred to use a single endless conveyor in the apparatus described above, it will be understood that the conveyor means may comprise two separate conveyors arranged in a suitable manner.

Thus, the separate conveyors would transport the material through the chamber in opposite directions with respect to each other, each conveyor being operative in a respective one of the conduits.

WHAT WE CLAIM IS: 1. Apparatus for carbonizing vegetable waste material, which apparatus comprises a tubular carbonizing chamber adapted to receive a fluid heating medium; conveying means conveying said waste material through said tubular carbonizing chamber and means for maintaining the material in fluid tight relationship in respect of said fluid heating medium and thereby isolated with respect to said medium yet surrounded thereby in a plane normal to the throughput of said conveying means to heat said waste material by indirect heat exchange as said waste material passes through said tubular carbonizing chamber.

2. Apparatus as claimed in claim 1, wherein the conveying means are arranged to pass the material along two paths in said tubular carbonizing chamber.

3. Apparatus as claimed in claim 2, wherein said paths are disposed parallel and one above the other in the operative position of the apparatus.

4. Apparatus as claimed in claim 3, wherein said paths comprise conduits which are interconnected by a connecting space for transferring material from the upper conduit to the lower conduit during operation of said conveying means.

5. Apparatus as claimed in any preceding claim, wherein said tubular chamber includes means allowing a sample of material to be taken from the lower path in the chamber.

6. Apparatus as claimed in any one of the preceding claims wherein said apparatus

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. In operation, a heating fluid, such as heated gas, is supplied to the manifold 16 so as to pass through the space defined between the tubular member 15 and the intermediate section 9 to provide muffle heating to the conduits 10 and 11, the gas exhausing through the manifold 17. Vegetable waste material is supplied to the feed chute 13. The space between the lower end of the baffles 113 and above the conveyor chain 3 is such as to provide a required volumetric measure, or quantity, of material in the housing 2 for collection by the conveyor chain 3 as it rotates.The conveyor chain 3 rotates in a clockwise direction as shown in the drawing so as to pass the material along the upper conduit 10 and into the carbonising chamber 15, 16, 17 until each portion of material arrives in the connecting space 12, clear of the upper conduit 10, where it drops through the conveyor chain onto the conveyor and/or is carried from the upper run of the conveyor to the lower run by the conveyor chain to be transported by the conveyor chain 3 along the lower conduit 11 towards the outlet 14. During passage of the material along the lower conduit 11, samples may be taken as required through the valve member 114. The vegetable waste material is heated by indirect heat exchange and on completion of carbonisation, the material is released, by gravity, from the apparatus through the outlet 14 for disposal elsewhere. Any gases generated in the upper conduit 10 and/or the lower conduit 11 are exhausted from the connecting space 12 through exhaust port 18 to the gas outlet pipe 19 for disposal in the furnace. Heating fluid which is exhausted through the manifold 17 is reheated for subsequent use, or exhausted. It will be understood that the furnace is used to provide the heating fluid used for the carbonization. In order to maintain the quality of the final product i.e. charcoal, the apparatus includes means (not shown) for varying the speed of the conveyor within the housing 2, such means being responsive to signals indicative of temperature within the carbonization chamber and generated by the thermometers; signals indicative of other information can be emitted by suitable equipment to ensure optimum efficiency of the apparatus. It will be understood that the movement of material through the upper conduit of the apparatus, the direction of flow of gas produced or generated in the intermediate section, and the flow of heating fluid within the tubular member is all in the same direction thereby minimising the condensation of condensible gases within the upper conduit 10. Further, the temperature at the end of the carbonising chamber with respect to each conduit is maintained above the dew point odf the gases generated within the upper and lower conduits. It will be understood that in the lower conduit, the movement of the material being processed is towards the outlet 14. Further, it will be understood that retention of heat released during the exothermal reaction that takes place during carbonization, within the chamber, minimizes the heat required from the heating fluid passing through the tubular member 15 thereby obtaining maximum thermal efficiency. If the gas being burnt in the furnace (not shown) produces heat surplus to required ments of the apparatus, such surplus heat may be used in a waste heat application such as a boiler. Although it is preferred to use a single endless conveyor in the apparatus described above, it will be understood that the conveyor means may comprise two separate conveyors arranged in a suitable manner. Thus, the separate conveyors would transport the material through the chamber in opposite directions with respect to each other, each conveyor being operative in a respective one of the conduits. WHAT WE CLAIM IS:

1. Apparatus for carbonizing vegetable waste material, which apparatus comprises a tubular carbonizing chamber adapted to receive a fluid heating medium; conveying means conveying said waste material through said tubular carbonizing chamber and means for maintaining the material in fluid tight relationship in respect of said fluid heating medium and thereby isolated with respect to said medium yet surrounded thereby in a plane normal to the throughput of said conveying means to heat said waste material by indirect heat exchange as said waste material passes through said tubular carbonizing chamber.

includes manifolds allowing the introduction and exhaust of the fluid heating medium to and from, respectively, the interior of the carbonizing chamber.

7. Apparatus as claimed in any one of the preceding claims and including volumetric measuring means to enable a correct load of material to be charged onto and to be moved by said conveying means through said carbonizing chamber, said measuring means with a charge of waste material restricting the ingress of the atmosphere to said carbonizing chamber.

8. Apparatus as claimed in any preceding claim wherein said conveying means comprise an endless conveyor having a path extending along each said conduit.

9. Apparatus as claimed in claim 8 and including drive transmission means for transmitting driving motion to said endless conveyor.

10. Apparatus as claimed in claim 9 and including means for varying the speed of said conveyor as it travels along said paths.

11. Apparatus as claimed in claim 10 wherein the variable speed means is responsive to a signal indicative of temperature in said carbonizing chamber.

12. Apparatus for carbonizing vegetable waste material the apparatus being substantially as herein described with reference to, and as shown in. the figures of the accompanying drawing.