GB2484409A

GB2484409A - Organic waste composter

Info

Publication number: GB2484409A
Application number: GB1117378.8A
Authority: GB
Inventors: James Leahy
Original assignee: Individual
Current assignee: Individual
Priority date: 2010-10-08
Filing date: 2011-10-10
Publication date: 2012-04-11
Also published as: IE20100647A1; IE20110453A1; GB201117378D0

Abstract

An organic waste composter has a vertically orientated processing vessel having a tank 1 with heating units 10, 13), a stirring mechanism 8, 8a,9, 9a, a means for injection of preheated air (11, 12, fig. 3), a waste inlet and a waste overflow/outlet 6 at an upper section of the vessel. The waste is fed in through unit 20 which is formed with a waste mincing mechanism. Auger 34 feeds material into the vessel at a bottom end. Heating units 10 are controlled by temperature sensors (41, fig. 2 ) and controller (40, fig. 2).

Description

AN ORGANIC WASTE COMPOSTER

The present invention relates to an organic waste composter and in particular to a vertically orientated organic waste composter for compacting organic waste.

It is no longer possible to send waste food to landfill and the leachate generated from processing organic waste can no longer be dispersed into waterways as a result of leakage nor spread on the ground where animals are immediately grazing. Therefore, there exists a requirement for industrial composting of organic waste in a controlled efficient manner whilst meeting health and safety regulations. The process of com posting is improved by having a standard size of material entering the com posting vessel. Furthermore, the ongoing industrial composting process requires all of the moving parts to operate with as little mechanical resistance as possible.

It is an object of the present invention to obviate or mitigate the problem of non standard size particles entering the processing vessel as well as ensuring there are no blockages to the flow of waste material during the ongoing composting process.

Accordingly, the present invention provides an organic waste composter comprising a vertically orientated processing vessel having a tank with at least one heating unit, a stirring mechanism, a means for injection of air for composting waste, a waste inlet and a waste overflow.

Preferably, the air is preheated.

Advantageously, the heating units reduce the time required for the composite dry and wet waste material to reach the optimum composting temperature. Under non controlled conditions composite waste material of this type would rise to an operating temperature of approximately 63/64° Celsius within approximately 8 days. Furthermore, under strict legislation to prevent the growth of harmful microorganisms such as pathogens, the time required for safe composting depends on the temperature of the material. At 63° C the composting time is approximately 2 days whereas at 72° C the composting time is approximately 1 hour. Advantageously, the heating units can maintain the composite material at an appropriate temperature to ensure safe decomposition of the waste material in a predetermined timescale.

Ideally, an evaporate discharge outlet with outlet pipe work and a condenser located within the pipe work are provided at the upper end of the vessel. Advantageously, heat can be recovered from the condenser and fed back into the system.

Preferably, a filter is provided at the free end of the pipe work.

Preferably, the organic waste composter has a separate waste feeder unit having a waste mincing mechanism.

Ideally, an auger extends between an outlet of the mincing mechanism and a waste inlet of the processing vessel, the auger being gently inclined upwards from the outlet of the mincing mechanism to the waste inlet of the processing vessel.

Preferably, the stirring mechanism comprises a powered central shaft extending vertically along the vertically orientated vessel with a plurality of vertically spaced agitators.

Ideally, at least one of the agitators is in periodic alignment with the waste inlet of the processing vessel. Advantageously, the periodic alignment of the at least one agitator with the waste inlet of the processing vessel means that the agitator sweeping past the waste inlet opening creates a space for incoming waste fed into the vessel via the auger.

Preferably, the free end of at least one agitator sweeps out a circle proximal to the internal wall of the vessel.

Alternatively, the agitators vary in diameter, size and shape.

Ideally, the speed and direction of rotation of the agitators is variable.

Preferably, the angle of the main plane of at least one agitator is inclined to the horizontal to urge the composite waste material generally upwardly in the vessel.

Preferably, a cowl is located above the waste inlet of the processing vessel.

Advantageously, the cowl located above the waste inlet opening in combination with the sweeping agitator periodically aligned with the waste inlet opening prevents waste in the vessel stacking up below the waste inlet opening. The sweeping agitator and cowl combination removes the newly inserted waste from this area mixing it with composite waste material in the vessel.

Ideally, the width of the cowl equals or exceeds the diameter of the solid waste inlet opening.

Preferably, the waste mincing mechanism is located at or about the lower end of the feeder unit.

Ideally, the feeder unit comprises a bin with at least the lower portions of at least some of the walls of the bin tapering towards the waste mincing mechanism in the lower end of the feeder unit.

Ideally, the waste mincing mechanism is located in a vertical wall of the feeder unit.

Advantageously, the waste mincing mechanism performs a combination of slicing and extrusion.

Preferably, the waste mincing mechanism comprises a rotatable slicer disc having a circular base plate having protruding elements situated around perforations in the base plate to form a passage through the base plate. Advantageously, the dimensions of the perforations can be set so that the maximum particle size of the minced waste material is predetermined as accurately as possible. This avoids a large range of material size being fed into the vessel increases the likelihood of a homogenous end product of dry compost.

Ideally, the protruding elements are provided with a sharp leading edge around the perforations pointing into the direction of rotation of the slicer disc.

Preferably, the protruding elements are elliptical raised portions.

Preferably, one or more stationary counter-blades are positioned perpendicular to the slicer disc.

Ideally, one or more additional counter blades with a sharp edge facing the slicer disc are positioned on the reverse side of the slicer disc.

Ideally, a gap exists between the sharp edge and the slicer disc. Advantageously, as the minced waste material is extruded through the perforations of the slicer disc, the sharp edge of the additional counter blades perform one final mincing of the waste particles.

Preferably, the waste mincing mechanism is driven by a motor.

Preferably, a screen filter and one end of the auger are located below the mincing mechanism.

Ideally, the auger is situated above the screen filter.

Preferably, the end of the auger below the screen filter is exposed. Advantageously, this exposed end of the auger allows minced waste material to engage the auger and commence the journey up along the auger.

Preferably, a collector box is located below the screen filter and a liquid waste discharge pipe gently inclines downwardly from the collector box to a liquid waste inlet at the base of the vessel. The waste discharge pipe is preferably only utilized when waste consisting almost entirely of liquid waste is fed into the feeder unit bin. In this instance the auger is unable to move this type of waste up into the vessel. The collector box is also suitable for collecting leachant expunged from the waste material as the material is minced and extruded through the waste mincing mechanism.

Ideally, a bypass pump is provided in fluid communication with the collector box for pumping this liquid waste into the vessel. In use, detection means can identify when liquid only waste is passing through the bin and the bypass pump can be engaged. This detection means can be a human operator.

Ideally, the vertically orientated vessel is enclosed by an insulation layer.

Advantageously, the insulation layer prevents heat loss maintaining the composting temperature and the efficiency of the process.

Preferably, a heating unit is located proximal to the base of the vessel.

Ideally, the heating unit is located below a base of the vessel.

Preferably, the heating unit comprises a metal plate having at least one aperture containing at least one heating element.

Ideally, a second heating unit is located proximal the top end of the vessel.

Preferably, the second heating unit also comprises a metal plate having at least one aperture containing at least one heating element.

Ideally, the second heating unit has a central aperture for receiving the central shaft.

Ideally, the second heating unit is located just below the compost overflow outlet.

Preferably, an agitator is located above the second heating unit. Advantageously, the agitator above the second heating unit urges compost towards the compost overflow outlet.

Ideally, the or each heating unit is controllable by a control means.

Preferably, temperature sensor means are provided in the vessel at various locations and the temperature sensors provide data to the control means.

Ideally, the control means has means for adjusting the power output of the or each heating unit in response to feedback from the temperature sensor means.

Preferably, the temperature sensor means comprise temperature probes.

Ideally, the means for injection of preheated air for composting waste is provided by one or more pipes extending from outside the vessel through the vessel wall and being coupled to one or more horizontally positioned rods which are hollow and perforated.

Preferably, the length of the horizontally positioned rods extend from the vessel walls is proximal to the centre shaft.

Preferably, the air is preheated using heat recovered from the condenser in the evaporate outlet pipe work.

Ideally, the inclined angle of the auger is greater than 4° to the horizontal.

Preferably, the inclined angle is greater than 6° to the horizontal.

Ideally, the inclined angle is less than 100 to the horizontal.

Preferably, the inclined angle is less than 8° to the horizontal.

Most preferably, the inclined angle is 7° to the horizontal.

Ideally, the inclined angle of the main plane of the at least one agitator is greater than 25° to the horizontal.

Preferably, the inclined angle of the main plane of the at least one agitator is greater than 28° to the horizontal.

Ideally, the inclined angle of the main plane of the at least one agitator is less than 35° to the horizontal.

Preferably, the inclined angle of the main plane of the at least one agitator is less than 32° to the horizontal.

Most preferably, the inclined angle of the main plane of the at least one agitator is 30° to the horizontal.

Ideally, the motor of the central shaft is operably coupled to the control means.

Preferably, the motor of the auger is operably coupled to the control means.

Ideally, the motor of the waste mincing mechanism is operably coupled to the control means. Advantageously, the control means can adjust the power delivered to any one of or any combination of motors to adjust the speed of any one of or any combination of the central shaft, the auger or the waste mincing mechanism in response to feedback from the temperature probes. Additional sensors to determine the density/viscosity of the waste material as it rises up the vessel can be operably coupled to the control means to allow further adjustment of the heating units and/or one or more motors.

Preferably, the waste mincing mechanism comprises a plurality of slicer discs and associated counter blades in a cascade formation wherein said slicer plates and blades have various sizes and shapes to provide various stages of refining the waste material fragments.

Ideally, the speed and direction of the rotation of the slicer discs is variable.

Ideally, valve means are provided at the waste inlet opening of the vessel.

Advantageously, the valve means allows the waste material to be delivered from the auger into the vessel but prevents the waste material escaping out of the vessel back down along the auger.

Ideally, a vessel comprising multiple stirring mechanisms is provided.

Preferably, the feeder unit for this embodiment has multiple augers and multiple liquid waste discharge pipes.

The invention will now be described with reference to the accompanying drawings which shows by way of example only two embodiments of an organic waste composter in accordance with the invention. In the drawing: Figure 1 is a front elevation sectional view of the organic waste composter; Figure 2 is a perspective pad sectional view of the organic waste composter; Figure 3 is a partial perspective pad sectional view of the organic waste composter; Figure 4 is a partial perspective pad sectional view of a mincing mechanism and auger; Figure 5 is a detail perspective pad sectional view of the mincing mechanism; Figure 6 is a second detail perspective pad sectional view of the mincing mechanism from an alternative angle; Figure 7 is a padial pad sectional perspective view of a second embodiment of feeder unit; and Figure 8 is a padial top plan pad sectional view of an auger.

Referring to the drawings and initially to Figures 1 to 3, there is shown an organic waste composter indicated generally by the reference numeral 101 having a vedically orientated processing vessel 1 comprising a tank 1 with heating units 10, 13, a stirring mechanism 8, 8a, 9, 9a, an arrangement 11, 12 for injection of air preferably preheated for composting waste and a waste overflow 6. Advantageously, the heating units 10, 13 reduce the time required for the composite dry and wet waste material to reach the optimum com posting temperature. Under non controlled conditions composite waste material of this type would rise to an operating temperature of approximately 63164° Celsius within approximately 8 days. Fudhermore, under strict legislation to prevent the growth of harmful microorganism such as pathogens, the time required for safe com posting depends on the temperature of the material. At 63° C the composting time is approximately 2 days whereas at 72° C the composting time is approximately I hours. Advantageously, the heating units 10, 13 can maintain the composite material at an appropriate temperature to ensure safe decomposition of the waste material in a predetermined timescale.

An evaporate discharge outlet 7c with outlet pipe work 7 and a condenser 7a located within the pipe work 7 are provided at the upper end of the vessel 1. Advantageously, heat

S

can be recovered from the condenser 7a and fed back into the system. A filter 7b is provided at the free end of the pipe work 7. The organic waste composter 101 has a separate waste feeder unit 20 having a waste mincing mechanism 22, 22a, 22b, 23, 24, 24a see especially Figures 4 to 6.

An auger 27, 30, 31 extends between an outlet of the mincing mechanism 22, 22a, 22b, 23, 24, 24a and a waste inlet of the processing vessel 1. The auger 27, 30, 31 is gently inclined upwards from the outlet of the mincing mechanism 22, 22a, 22b, 23, 24, 24a to the waste inlet of the processing vessel 1. The stirring mechanism 8, 8a, 9, 9a has a powered central shaft 8 extending vertically along the vertically orientated vessel I with five vertically spaced agitators 9a, 9b. One of the agitators 9a is in periodic alignment with the waste inlet of the processing vessel 1. Advantageously, the periodic alignment of the agitator 9a with the waste inlet of the processing vessel 1 means that the agitator 9a sweeping past the waste inlet opening creates a space for incoming waste fed into the vessel via the auger 27, 30 31.

The free end of each agitator 9a, 9b sweeps out a circle proximal to the internal wall of the vessel 1. Alternatively, the agitators 9a, 9b vary in diameter, size and shape. The speed and direction of rotation of the agitators 9a, 9b is variable. The angle of the main plane of at least one of the agitators 9b is inclined to the horizontal to urge the composite waste material generally upwardly in the vessel 1.

A cowl 35 is located above the waste inlet of the processing vessel 1.

Advantageously, the cowl 35 located above the waste inlet opening in combination with the sweeping agitator 9a periodically aligned with the waste inlet opening prevents waste in the vessel I stacking up below the waste inlet opening. The sweeping agitator 9a and cowl 35 combination removes the newly inserted waste from this area mixing it with composite waste material in the vessel 1. The width of the cowl 35 equals or exceeds the diameter of the solid waste inlet opening.

Referring more particularly to Figures 4, 5 and 6 the waste mincing mechanism 22, 22a, 22b, 23, 24, 24a is located at or about the lower end of the feeder unit 20. The feeder unit 20 comprises a bin 20 with at least the lower portions of at least some of the walls of the bin 20 tapering towards the waste mincing mechanism 22, 22a, 22b, 23, 24, 24a in the lower end of the feeder unit 20. The waste mincing mechanism 22, 22a, 22b, 23, 24, 24a is located in a vertical wall 21 of the feeder unit 20. Advantageously, the waste mincing mechanism 22, 22a, 22b, 23, 24, 24a performs a combination of slicing and extrusion. The waste mincing mechanism 22, 22a, 22b, 23, 24, 24a comprises a rotatable slicer disc 22 having a circular base plate 22 with protruding elements 22a situated around perforations 22b in the base plate 22 to form a passage through the base plate 22. Advantageously, the dimensions of the perforations 22b can be set so that the maximum particle size of the minced waste material is predetermined as accurately as possible. This avoids a large range of material size being fed into the vessel 1 increasing the likelihood of a homogenous end product of dry compost.

The protruding elements 22a are provided with a sharp leading edge around the perforations 22b pointing into the direction of rotation of the slicer disc 22. The protruding elements 22a are elliptical raised portions. Two stationary counter-blades 23 are positioned perpendicular to the slicer disc 22. Two additional counter blades 24 with a sharp edge 24a facing the slicer disc 22 are positioned on the reverse side of the slicer disc 22. A gap exists between the sharp edge 24a and the slicer disc 22. Advantageously, as the minced waste material is extruded through the perforations 22b of the slicer disc, the sharp edge 24a of the additional counter blades 24 perform one final mincing of the waste particles. The waste mincing mechanism 22, 22a, 22b, 23, 24, 24a is driven by a motor 25.

Referring to Figure 4, a screen filter 26 and one end of the auger 27, 30, 31 are located below the mincing mechanism 22, 22a, 22b, 23, 24, 24a. The auger flight may be continuous or discontinuous as shown in Figures 7 and 8. The auger 27, 30, 31 is situated above the screen filter 26. The end of the auger 27 below the screen filter 26 is exposed.

Advantageously, this exposed end of the auger 27 allows minced waste material to engage the auger 27 and commence the journey up along the auger 27 towards the vessel 1. A collector box 32 is located below the screen filter 26 and a liquid waste discharge pipe 33 gently inclines downwardly from the collector box 32 to a base 3 of the vessel 1. The waste discharge pipe 33 is preferably only utilized when waste consisting almost entirely of liquid waste is fed into the feeder unit bin 20. In this instance the auger 27 is unable to move this type of waste up into the vessel 1. The collector box 32 is also suitable for collecting leachant expunged from the waste material as the material is minced and extruded through the waste mincing mechanism 22, 22a, 22b, 23, 24, 24a. A bypass pump, not shown, is provided in fluid communication with the collector box 32 for pumping this liquid waste into the vessel 1.

In use, a detection facility can identify when liquid only waste is passing through the bin 20 and the bypass pump can be engaged. This detection facility can be a human operator.

Referring to Figures 1 to 3, the vertically orientated vessel I is enclosed by an insulation layer la, 2a, 3a. Advantageously, the insulation layer Ia, 2a, 3a prevents heat loss maintaining the composting temperature and the efficiency of the process. A heating unit 10 is located proximal to the base 3 of the vessel 1. The heating unit 10 is located below a base of the vessel 1. The heating unit 10 has a metal plate having an aperture containing a heating element. A second heating unit 13 is located proximal the top end of the vessel 1.

The second heating unit 13 also comprises a metal plate having an aperture containing a heating element. The second heating unit 13 has a central aperture 102 for receiving the central shaft 8. The second heating unit 13 is located just below the compost overflow outlet 6. An agitator, not shown, is located above the second heating unit 13. Advantageously, the agitator above the second heating unit 13 urges compost towards the compost overflow outlet 6.

The heating units 10, 13 are controlled by a controller 40. Temperature sensors 41 are provided in the vessel I at various locations and the temperature sensors 41 provide data to the controller 40. The controller 41 has a control program or hardware for adjusting the power output of either or both heating units 10, 13 in response to feedback from the temperature sensors 41. The temperature sensors 41 are temperature probes.

The arrangement 11, 12 for injection of preheated air for composting waste is provided by one or more pipes 11 extending from outside the vessel I through the vessel wall and being coupled to one or more horizontally positioned rods 12 which are hollow and perforated. The length of the horizontally positioned rods 12 extend from the vessel walls proximal to the centre shaft 8. The air can be preheated using heat recovered from the condenser 7a in the evaporate outlet pipe work 7.

The inclined angle of the auger 27 is in a range of between 4° to the horizontal and to the horizontal and most preferably, the inclined angle is 7° to the horizontal. The inclined angle of the main plane of at least one agitator 9b is in a range between 25° to the horizontal and 35° to the horizontal and most preferably, the inclined angle of the main plane of the at least one agitator 9b is 30° to the horizontal.

The motor 8a of the central shaft 8 is operably coupled to the controller 40. The motor 27a of the auger 27 is operably coupled to the controller 40. The motor 25 of the waste mincing mechanism 22, 22a, 22b, 23, 24, 24a is operably coupled to the controller 40.

Advantageously, the controller 40 can adjust the power delivered to any one of or any combination of motors 8a, 27a, 25 to adjust the speed of any one of or any combination of the central shaft 8, the auger 27 or the waste mincing mechanism 22, 22a, 22b, 23, 24, 24a in response to feedback from the temperature probes 41 or other density/viscosity sensors.

In a second embodiment, shown in Figures 7 and 8, a feeding bin 28 is shown where the waste material is dropped onto a spring loaded gate 29 which drops the organic waste onto an exposed portion of the auger 27 along a substantial portion of the length of the auger 27. This embodiment improves the traction between the waste and the auger where a greater surface area of the auger 27 is exposed to a greater quantity of waste material.

In an embodiment not shown in the drawings, the waste mincing mechanism comprises a plurality of slicer discs and associated counter blades in a cascade formation wherein said slicer plates and blades have various sizes and shapes to provide various stages of refining the waste material fragments. The speed and direction of the rotation of the one or more slicer discs is variable. A valve member not shown is provided at the waste inlet opening of the vessel 1. Advantageously, the valve member allows the waste material to be delivered from the auger 27 into the vessel 1 but prevents the waste material escaping out of the vessel I back down along the auger 27.

In a further embodiment not shown in the drawings, a vessel comprising multiple stirring mechanisms is provided. The feeder unit for this embodiment has multiple augers and multiple liquid waste discharge pipes.

In relation to the detailed description of the different embodiments of the invention, it will be understood that one or more technical features of one embodiment can be used in combination with one or more technical features of any other embodiment where the transferred use of the one or more technical features would be immediately apparent to a person of ordinary skill in the art to carry out a similar function in a similar way on the other embodiment.

In the preceding discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of the said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

The features disclosed in the foregoing description or the following drawings, expressed in their specific forms or in terms of a means for performing a disclosed function, or a method or a process of attaining the disclosed result, as appropriate, may separately, or in any combination of such features be utilised for realising the invention in diverse forms thereof as defined in the appended claims.

Claims

CLAIMS1. An organic waste composter comprising a vertically orientated processing vessel having a tank with at least one heating unit, a stirring mechanism, a means for injection of air for com posting waste, a waste inlet and a waste overflow.
2. An organic waste com poster as claimed in claim 1, wherein an evaporate discharge outlet with outlet pipe work and a condenser located within the pipe work are provided at the upper end of the vessel.
3. An organic waste com poster as claimed in claim 1 or claim 2, wherein the organic waste com poster has a separate waste feeder unit having a waste mincing mechanism.
4. An organic waste composter as claimed in claim 3, wherein an auger extends between an outlet of the mincing mechanism and the waste inlet of the processing vessel, the auger being gently inclined upwards from the outlet of the mincing mechanism to the waste inlet of the processing vessel.
5. An organic waste com poster as claimed in any one of the preceding claims, wherein the stirring mechanism comprises a powered central shaft extending vertically along the vertically orientated vessel with a plurality of vertically spaced agitators.
6. An organic waste com poster as claimed in claim 5, wherein at least one of the agitators is in periodic alignment with the waste inlet of the processing vessel.
7. An organic waste composter as claimed in any one of claims 5 or 6, wherein the free end of at least one agitator sweeps out a circle proximal to the internal wall of the vessel.
8. An organic waste com poster as claimed in any one of claims 5 to 7, wherein the angle of the main plane of at least one agitator is inclined to the horizontal to urge the composite waste material generally upwardly in the vessel.
9. An organic waste com poster as claimed in any one of the preceding claims, wherein a cowl is located above the waste inlet of the processing vessel.
10. An organic waste composter as claimed in claim 9, wherein the width of the cowl equals or exceeds the diameter of the solid waste inlet opening.
11. An organic waste com poster as claimed in any one of claims 3 to 10, wherein the waste mincing mechanism is located at or about the lower end of the feeder unit.
12. An organic waste composter as claimed in any one of claims 3 to 11, wherein the feeder unit comprises a bin with at least the lower portions of at least some of the walls of the bin tapering towards the waste mincing mechanism in the lower end of the feeder unit.
13. An organic waste composter as claimed in any one of claims 3 to 12, wherein the waste mincing mechanism is located in a vertical wall of the feeder unit.
14. An organic waste composter as claimed in any one of claims 3 to 13, wherein the waste mincing mechanism comprises a rotatable slicer disc having a circular base plate having protruding elements situated around perforations in the base plate to form a passage through the base plate.
15. An organic waste composter as claimed in claim 14, wherein the protruding elements are provided with a sharp leading edge around the perforations pointing into the direction of rotation of the slicer disc.
16. An organic waste composter as claimed in claim 14 or 15, wherein one or more stationary counter-blades are positioned perpendicular to the slicer disc.
17. An organic waste composter as claimed in any one of claims 14 to 16, wherein one or more additional counter blades with a sharp edge facing the slicer disc are positioned on the reverse side of the slicer disc.
18. An organic waste com poster as claimed in any one of claims 3 to 17, wherein a screen filter and one end of the auger are located below the mincing mechanism.
19. An organic waste composter as claimed in claim 18, wherein a collector box is located below the screen filter and a liquid waste discharge pipe gently inclines downwardly from the collector box to a liquid waste inlet at a base of the vessel.
20. An organic waste composter as claimed in any one of the preceding claims, wherein a heating unit is located below a base of the vessel.
21. An organic waste com poster as claimed in any one of the preceding claims, wherein a second heating unit is located proximal the top end of the vessel.
22. An organic waste com poster as claimed in claim 20 or 21, wherein the heating unit comprises a metal plate having at least one aperture containing at least one heating element.
23. An organic waste composter as claimed in any one of the preceding claims, wherein the or each heating unit is controllable by a control means.
24. An organic waste com poster as claimed in claim 23, wherein temperature sensor means are provided in the vessel at various locations and the temperature sensors provide data to the control means.
25. An organic waste composter as claimed in claim 23 or 24, wherein the control means has means for adjusting the power output of the or each heating unit in response to feedback from the temperature sensor means.
26. An organic waste composter as claimed in any one of the preceding claims, wherein the means for injection of preheated air for composting waste is provided by one or more pipes extending from outside the vessel through the vessel wall and being coupled to one or more horizontally positioned rods which are hollow and perforated.
27. An organic waste composter substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.