Patent Application
20080022739
The invention will be better understood and objects other than those set forth above will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein:
Referring to
Collectively, these views show the inventive apparatus 100 comprises a vessel housing 110 having at least one housing wall 120. For purposes of composting waste according to the present invention, the vessel is preferably either generally cylindrical, in which event the wall is singular and contiguous, or cuboid, in which event the housing has four walls comprising sides. However, in the first preferred embodiment the vessel housing is cuboid and is supported on a frame 130. Vessel dimensions will vary according to the scale of the composting operation, though heights ranging from approximately nine to eighteen meters (thirty to sixty feet) have proven most serviceable and work best for materials processed for a typical resonance time in a plug-flow system.
A waste inlet 140 is located at the top of the housing above an upper processing zone 150. The inlet may be either directly above the upper processing zone or to the side, depending upon the means provided for distributing and spreading the waste before introduction into the first processing zone. Positioned below the first processing zone is a lower processing zone 160, and the two zones are brought into communication with one another through a processing zone passageway 155.
Waste introduced into the housing through the waste inlet is leveled and evenly distributed over the upper processing zone by leveling means 170, preferably comprising at least one auger screw having either continuous solid or ribbon flights. It will be appreciated, however, that numerous suitable alternative means may be employed, including, for instance, a rotary leveler. The at least one auger screw is driven by a reversible motor 180, which permits periodic and systematic movement of the waste material in each direction along the length of the auger screw.
At least one agitating device 190 is interposed between the upper processing zone 150 and the lower processing zone 160. Preferably, the agitating device comprises a first set of side-by-side tumble roll feeder 200, 210, each of which include a plurality of radially disposed surface paddles or bars 220. The tumble roll feeders are actuated by one or more reversible motors, 230. When operated, the rollers are preferably rotated in opposite directions such that when viewed from either end, the left hand roller rotates clockwise and toward the right hand roller, and the right hand roller rotates counterclockwise and toward the left hand roller. However, each tumble roll feeder may also be rotated in the opposite direction, as long as both rollers are not simultaneously rotated in the same direction.
In alternative embodiments, the agitating device may be replaced by a different, non-agitating device such as a stationary grid, bars, a moving floor, slide gate, or a hatch. In these embodiments, the device, which separates the different zones in the apparatus, keeps the weight of compost material in the upper region of the composting apparatus from compressing compositing material at the lower region of the composting apparatus. The fundamental concept of processing the compost in vertically disposed but discrete processing zones is nonetheless preserved in such embodiments.
In the preferred embodiments of the present in invention, a lower agitation device 250 is positioned at the base of the lower processing zone 160. Preferably the agitation device comprises a second set of side-by-side rollers 260, 270 that operate in the manner as described above. The second set of rollers is actuated by at least one second motor 280.
Throughout the composting cycle, the agitation means are operated at predetermined intervals. The agitators mix, delump, aerate, and turn over the compost material inside vessel. The agitation means also support the compost material above them so that the full weight of compost pile does not compact the compost material below it, thereby limiting oxygen supply to material deep within the pile. Effective agitation can be enhanced by the provision of one or more baffle plates 240 positioned on the interior surface(s) of the vessel housing, which direct the bulk volume into the agitator paddles or rollers. Alternatively, the vessel housing itself include inwardly tapering walls 290, in the fashion of a hopper, to direct the material flow into the agitators and through the passageway at the lower portion of the processing zone.
A discharge outlet 300 is positioned directly below the lower agitation device. This portion of the vessel housing is configured to direct finished compost into a discharge conveyor system 310, preferably a screw auger, which transports nutrient rich plant growth media from the apparatus to holding bins or other containers to await use.
For large scale processing of biodegradable waste, it is preferable for the inventive system to include a waste input conveyor system 320, preferably a vertically disposed bucket conveyor. The preference of conveyor type is driven by the angle or orientation of the system, and the orientation advances the space-saving purpose of the inventive apparatus, though it is not critical to its effective function. Thus, alternative systems could be employed if the conveyor were more horizontally disposed. The waste input conveyor system includes a waste loading inlet 330, a vertically disposed tube 340, a motor driven bucket conveyor cable 350, and a material outlet 360, all of which are well known in the art.
Misting nozzles 370 may be positioned in any processing zone to accomplish several purposes, including: increasing atmospheric humidity; increasing the water content of the compost pile; and washing leachate residue from the upper portions of the leachate retention gate (described and discussed in detail below). Optimally added water will not be required in the upper processing zone.
Environmental control systems may be provided to tightly regulate the conditions under which the material is processed during the resonance period. As noted, misting nozzles can be provided to add water to selected processing zones. Additionally, temperature, oxygen level, and moisture level sensors may be installed in one or more of the processing zones so that adverse conditions can be corrected promptly. The sensors are not shown as they are common and well known in the art. The system may further include gas outlet duct 380 for venting and removing exhaust gasses produced by the composting process. The air removed from the system may be processed in a bio-filter 390, released directly into the atmosphere (if appropriate and permitted), or directed into a ground berm. Either fresh or recycled air may be directed into the vessel housing via air inlet 400, and such may be heated or cooled by a heating and cooling unit 410, preferably co-located with the bio-filter. All of the environmental systems are preferably coordinated with one another, as well as with the agitation systems, through programmable logic means, either a programmable logic controller or a computer 420.
The essential improvement provided by the present inventive system and apparatus is a novel compost leachate retention system. This novel system is illustrated in all of the figures, which collectively show four preferred embodiments. The first embodiment is illustrated in
The inboard (drain side) gutter 530 includes a drain 540 in fluid communication with a pump 550 via a pump inlet hose 560. The pump sends collected leachate fluid through a pump outlet hose 570 for further processing in the compost apparatus, or otherwise directs the collected liquids to a receptacle or dedicated drain for proper disposal or bio-remediation.
Next, the leachate gate is pivotally connected through an axle 580 to mechanical means for swinging the door downwardly into a open position 590, so as to permit the compost material to pass from the upper processing zone into the lower processing zone, and then to raise the door back into a closed position 600 for capturing and draining compost leachate. Preferably the mechanical means is at least one, and preferably two, linear actuators, such as hydraulic cylinders 610a, 610b, powered by a hydraulic system (not shown), as is well known in the art. The cylinders are pivotally attached to horizontal rails 615 of the housing frame at pivot points 620a, 620b, and drives lever arms 630a, 630b, each rigidly coupled to the rotatable axle 580.
It will be appreciated that the leachate gate is preferably angled slightly downwardly toward the drain side gutter when in the closed position so that leachate, either diluted or undiluted, and other fluids do not cause the gate to overflow and so as to provide for continuous drainage from the catch basin.
Referring now to
The reduced size of the leachate gate in the second preferred embodiment necessitates a repositioning of the axle 760 through which the leachate gate is rigidly connected to first and second lever arms 770a, b, which are pivotally connected to first and second hydraulic cylinders 780a, 770b, which are in turn pivotally connected at pivot points 790a, 790b to vertical support members 800 of the housing frame.
In a third preferred embodiment of the present invention 900, the leachate retention system 910 employs a telescoping slide gate 920 rather than a swinging gate.
The telescoping slide gate is mounted on brackets 950 installed on and affixed to the housing frame 130. The gate itself includes a plurality of telescoping members 960, including an outermost telescoping member 970 having a cylinder connection bracket 980 for connection of the cylinder rod 990, and further including a fixed base member 1010, which includes a drain 1020. All of the telescoping members have turned up sides, and the outermost telescoping member has a turned up end 1030. Further, the fixed base member includes a pocket 1040 into which all telescoping members nest when the gate is collapsed. However, an outboard gutter is not required in this embodiment inasmuch as the gate is not swung either upwardly or downwardly during operation. However, the gate is extended, it is angled slightly from its outermost telescoping member downwardly to the innermost telescoping member so that liquids captured by the gate naturally run down to the drain in the innermost telescoping member.
The hydraulic cylinder 1030 may be a single-acting external return linear actuator with piston and rod travel sufficient to extend the telescoping gate underneath the passageway between the baffles. In such a case, the cylinder may be installed at the mounted end of the gate and will extend a short distance outside the housing frame. Alternatively, the hydraulic cylinder can itself be a telescoping cylinder which collapses substantially in coordination with the collapsing gate, and thus need not extend significantly outside the vertical composter housing.
A fourth preferred embodiment of the present invention is shown in
As with the earlier embodiments, the fourth preferred embodiment includes actuators, preferably hydraulic cylinders 1190, which selectively open and close the clam shell halves. Other notable features of the inventive system include load cells 1200 for batch weighing compost volumes, temperature sensors 1210, one or more air cooling system blowers 1220, for introducing air into the composting zones, an air discharge blower 1230 for discharging clean air from the system, possibly through a bio-filter 1240, and misting valves 1250 for controlling the introduction of water spray into the processing zones. All of these environmental controls are under the control of a control system and monitor 1260, to which they are connected.
As
Method Steps: Referring now especially to
(1) Organic waste (biodegradable waste) is combined with a bulking agent (wood chips, sawdust, etc.) to achieve a proper carbon-to-nitrogen ratio and a correct porosity in waste material mixture.
(2) The organic waste and bulking agent are mixed thoroughly (typically in a automated four auger mixer, though this can also be accomplished with a front loader or an equivalent method).
(3) The mixed organic waste and bulking agent are loaded into a bucket elevator receiving hopper. This is typically accomplished with a conveyer, though it can also be done with a front loader or an equivalent method.
(4) The waste mixture is vertically conveyed by bucket elevator to the top of the composting apparatus.
(5) The waste mixture is deposited into the top of the composting apparatus.
(6) The waste mixture is distributed evenly in the horizontal plane by leveling screws into the upper processing zone in the composting apparatus.
(7) The waste mixture is retained in the upper processing zone for approximately seven days. Each day the waste mixture is moving down as compost is unloaded and new waste is added).
(8) The waste mixture reaches the agitation system rollers on approximately the seventh day.
(9) The waste mixture is turned, agitated, de-lumped and forced into the lower processing zone by the agitation system rollers.
(10) Water is added to the waste mixture if needed to maintain adequate moisture content after the waste mixture passes through the agitation system rollers.
(11) The waste mixture is retained in the lower processing zone for approximately seven additional days. Each day the waste mixture progressively moves down as compost is unloaded and new waste is added.
(12) After approximately the fourteenth day, retention in the composting apparatus waste mixture has been stabilized to meet pathogen destruction and vector attraction regulations and now comprises a nutrient rich plant growth media.
(13) Plant growth media is discharged from the bottom of the composting apparatus via screw conveyor or an equivalent method for further post processing (such as curing, drying, screening, bagging, etc.). It is loaded into transportation means which convey the processed compost to its destination for utilization.
Monitoring/Controls: The following controls and monitoring systems may be employed throughout the composting cycle to ensure the maintenance of optimum composting conditions:
(1) Vertically oriented temperature probes may be permanently fixed in the center of the composting mass to give continuous feedback to the control panel which activates fans or blowers to effectively regulate temperature and oxygen within the composting mass. The temperature may be controlled so as not to exceed 71° C. (160 degrees Fahrenheit) and not to go below 54° C. (131 degrees Fahrenheit). Positive air may be pushed by blowers into the bottom of the composting mass and negative air pressure is exerted on top of the composting mass to pull air from the top of the composting mass to a bio-filter. The bio-filter may include a specific mixture of stabilized mature compost, woodchips and other filtering media to clean exhaust air in order to prevent odor from being emitted into the surrounding environment. Other air filtration devices can be utilized to scrub or clean the air instead of a bio-filter.
(2) Moisture sensors can be positioned throughout the composting mass to give continuous feedback to the control panel which activates irrigation emitters to control moisture content of the composting material. The moisture level of the composting mass can be maintained at approximately 60% to optimize the composting process.
(3) Throughout the composting cycle, all compost leachate generated is captured, contained, and diverted for appropriate handling by the leachate retention system. Leachate is recycled and used for irrigation purposes or can be diverted to a drain or container for appropriate disposal. This control step is the heart of the present inventive system.
The foregoing disclosure is sufficient to enable one having skill in the art to practice the invention without undue experimentation, and provides the best mode of practicing the invention presently contemplated by the inventor. While there is provided herein a full and complete disclosure of the preferred embodiments of this invention, it is not intended to limit the invention to the exact construction, dimensional relationships, and operation shown and described. Various modifications, alternative constructions, changes and equivalents will readily occur to those skilled in the art and may be employed, as suitable, without departing from the true spirit and scope of the invention. Such changes might involve alternative materials, components, structural arrangements, sizes, shapes, forms, functions, operational features or the like.
Accordingly, the proper scope of the present invention should be determined only by the broadest interpretation of the appended claims so as to encompass all such modifications as well as all relationships equivalent to those illustrated in the drawings and described in the specification.
