Abstract:
A U-shaped flexible tray for a compost bin having a rear wall, a front wall and a floor. The ends of the front and rear walls are releasably attached to upstanding mounting posts. Organic material is deposited into the bin and aerated, thereby forming compost. A tarp cover protects the compost from wind and rain. A forced air system beneath the bin forces air through the organic matter to promote composting. The composted product is unloaded by a bin emptying device having an upper roller that draws the rear wall forward, and a lower roller that draws the front wall forward, thereby shifting the weight of the compost. As the rollers tighten, the flexible tray is transformed from a U-shaped bin into a vertical wall, thereby moving the compost out of the bin. The flexible tray is then manually restored to its original mounting posts and the U-shape restored. The bin emptying device may advance on tracks to the next designated bin to resume emptying operations.

Description:
[0001]    This application claims priority from U.S. Provisional Patent Application No. 60/359,166 entitled “COMPOSTING SYSTEM,” filed on Feb. 21, 2002. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    1. Field of the Invention  
           [0003]    The present invention pertains generally to a system for composting organic material. Its main advantages arise from the ability to control the composting process with a minimum of operating costs and relatively low capital investment to produce a uniform, high-quality product. It has the ability to handle very large or small volumes of material. It has particular relevance to the organic waste recycling business, wastewater treatment operations and to the mushroom business.  
           [0004]    2. Description of Related Art  
           [0005]    Agricultural endeavors such as mushroom harvesting have long relied on composting to produce healthy and fertile soil. Composting involves taking organic matter and placing it in a “pile” that is then decomposed by bacteria into elemental soil-type material. The large volume of matter used in composting lowers the surface to volume ratio, thereby limiting both heat escape, and moisture escape. This serves to maintain an environment conducive for the bacteriological breakdown of the organic matter.  
           [0006]    In the past, composting has been performed in large piles that can weigh upwards of several tons, even upwards of tens or hundreds of tons. The management of such large masses is problematic. Even when forced air is used for aeration, as a compost pile increases in size, it is harder and harder to insure that air or moisture will be evenly distributed through the mass. As a result, one region within a large mass may be well reduced to compost matter, whereas another region remains largely uncomposted.  
           [0007]    The handling of massive compost piles is equally problematic. Manual labor using shovels and tools is labor intensive and, therefore, both expensive and inefficient. The capital investment for earth moving machines can also be significant, and the operation of such machines cumbersome.  
           [0008]    In view of the above, a need exists for a composting system that can handle massive quantities of organic material in workable sizes. There is further a need for a composting system that insures more even aeration and hydration. There is also a need for an efficient system for selecting and capturing a predetermined amount of compost matter from a compost mass.  
         SUMMARY OF THE INVENTION  
         [0009]    The present invention is directed to a composting system that can parcel massive quantities of organic material into workable sizes. In this way, the system ensures more even aeration and hydration. Additionally, an efficient system for selecting and capturing a predetermined amount of compost matter from a compost mass is provided.  
           [0010]    Still further, a method of managing compost material is disclosed that utilizes a flexible tray having a first end, a second end, and an air permeable mesh between the first and second end. The method comprises the steps of supporting the first end of the flexible tray from a first support unit, thereby forming a first side of an operational bin; supporting the second end of the flexible tray from a second support unit, thereby forming a second side of the operational bin; flexing the flexible tray such that a bin floor is formed by a portion of the flexible tray disposed between the first end and the second end of the flexible tray, wherein the floor comprises a portion of the air permeable mesh. A plane defined by the floor intersects planes defined by the first and second side.  
           [0011]    A volume of organic material is deposited from a large source of organic material into the operational bin. The volume of organic material is aerated within the operational bin and the organic material is substantially converted into compost. The first end of the flexible tray is then moved through a motion that comprises a horizontal component of motion in the direction of the second end; and the compost material is discharged from the operational bin.  
           [0012]    The step of moving the first end of the flexible tray advantageously comprises the steps of coupling the first end of the flexible tray to an upper grasping member of a tray emptying device wherein the upper grasping member is coupled to an upper tension member; winding the upper tension member on an upper roller of the tray emptying device; releasing the first end of the flexible tray from the first support unit; and winding a portion of the flexible tray onto the upper roller.  
           [0013]    According to one embodiment, the second end of the flexible tray is coupled to a lower grasping member of the tray emptying device. The lower grasping member is coupled to a lower tension member, and the lower tension member is wound onto a lower roller. A portion of the flexible tray can also be wound onto the lower roller.  
           [0014]    The operational bin is advantageously part of a bin complex that includes a previously used bin. According to another embodiment, the tray emptying device may be moved from a previous bin to an adjacent operational bin, and the operational bin may be moved to a position proximate the tray emptying device. In another embodiment, the system provides for progressively shifting the weight of the compost within the first bin onto a ramp prior to the step of discharging the compost from the operational bin.  
           [0015]    The compost managing system further comprises a plurality of bins including a first bin having a front wall, a rear wall and a floor formed from a single flexible tray. The front wall includes a first coupling member at a top of the wall, and the rear wall includes a second coupling member at a top of the rear wall. A front support functions to support the front wall in an upright position and a rear support functions to support the rear wall in an upright position.  
           [0016]    An aeration means comprises a forced air source for moving air into air supply ducts in fluid communication with air outlets disposed under the floor of the first bin. A tray emptying device for removing compost material from the first bin includes a first roller apparatus comprising a first drum roller coupled to a fixed end of a first tension member and a first gripping means coupled to a free end of the first tension member. The first gripping means is configured to grip the first coupling member attached to the top of the front wall.  
           [0017]    A second roller apparatus comprising a second drum roller is coupled to a fixed end of a second tension member, and a second gripping means is coupled to a free end of the second tension member. The second gripping means engages the second coupling member which is attached to the top of the rear wall. The first roller apparatus is configured to wind the first tension member around the first drum roller and the second roller apparatus is configured to wrap the second tension member around the second drum roller. The first drum is advantageously at a higher elevation than the second drum.  
           [0018]    In an alternative embodiment of the invention, the first coupling member comprises an S-hook, and the first coupling member comprises a rigid rod.  
           [0019]    The tray emptying device advantageously comprises a ramp forming a bottom of the tray emptying device. The second drum is configured to move a portion of the flexible tray onto the ramp. The first roller apparatus may include a motor for driving the first drum roller or a manual member for driving the first drum roller. A bin cover may be used above the first bin. A transit mechanism may also be provided to move the tray emptying device from bin to bin. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    The novel features of this invention will be best understood from the accompanying Figures, taken in conjunction with the accompanying description, in which similar characters refer to similar parts, and in which:  
         [0021]    [0021]FIG. 1 is an isometric view of the composting system of the present invention.  
         [0022]    [0022]FIG. 2 is a top plan view of a flexible tray for the system of FIG. 1.  
         [0023]    [0023]FIG. 2A is a top plan view of an alternative embodiment for the tray of FIG. 2A.  
         [0024]    [0024]FIG. 3 is a rear elevational view of a bin of the system of FIG. 1, which shows the manner in which forced air is introduced into each bin.  
         [0025]    [0025]FIG. 3A is a side elevational view of the bin of FIG. 3, which shows the manner in which a tarp can be optionally placed over the bin.  
         [0026]    [0026]FIG. 4 is an isometric view of the tray emptying device for the system of FIG. 1.  
         [0027]    [0027]FIG. 5 is side elevational view of the system of FIG. 1 during the initial stages of offloading the contents of a composting bin.  
         [0028]    [0028]FIG. 6 is the same view as FIG. 5 during the approximate mid-point of the offloading operation.  
         [0029]    [0029]FIG. 7 is the same view as FIG. 5 during the approximate endpoint of the offloading operation.  
         [0030]    [0030]FIG. 8 is a top plan view of the composting pallet of FIG. 1, with portions removed for clarity.  
         [0031]    [0031]FIG. 9 is a cross-sectional view as seen along lines  9  -  9  in FIG. 8.  
         [0032]    [0032]FIG. 10 is an isometric view of a saddle that is used in conjunction with the flexible tray of FIG. 2A. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0033]    Referring now to the Figures, the high volume composting system is shown and is generally designated by reference character  10 . In brief overview, the system comprises a plurality of flexible trays  12  which each rest upon a respective compost pallet  25 , a plurality of spaced-apart, hollow post uprights  17  to support the flexible trays and a plurality of evenly spaced-apart bin separation walls  14 . The bin separation walls, which are preferably made of a heavy-duty fabric or plywood material, extend between the post uprights on each side of a respective flexible tray and are fixed to the post uprights. Alternatively, the bin separation walls can be made of a heavy canvas material and attached to the post uprights with S-hooks  44  as described below. The flexible tray, post uprights and separation walls cooperate to define a plurality of compost bins  16 , as shown in FIG. 1.  
         [0034]    As shown in the Figures, the system includes a tray emptying device  15 . The tray emptying device facilitates offloading of each compost bin in a manner hereinafter described. With the above structure, large aggregate amounts of compost  18  can be divided into smaller, more manageable amounts that are defined by the volume of the bin. This allows for a more controlled manipulation of the composting process in a manner more fully described below.  
         [0035]    To aerate the compost  18  in each bin, thereby facilitating the composting process, the composting system of the present invention includes a forced air source  20 . A main air supply duct  22  is connected to the forced air source to supply pressurized air to the underside of each bin. Such forced air source provides the system with the capacity to not only oxygenate the compost therein, but also provides the capability to control the temperature within the compost mass, for maximum control over the overall composting process. The air may also be directed down through the compost versus being directed upwardly through the compost. This system provides the flexibility to operate in either mode.  
         [0036]    For each bin, and referring now primarily to FIGS. 1, 8 and  9 , each bin includes a corresponding composting pallet  25  that is connected to the main air supply duct at a quick disconnect fitting  26  in a manner known in the art (the quick disconnect fitting  26  is optional). As shown in FIG. 8, the pallet includes an upper board  29   a  and a spaced-apart lower board  29   b  (optional), that lie in horizontal planes that are about parallel to each other. A plurality of connector ducts  24  branch off from junction  28  and extend into the pallet and are fixed to the bottom of the upper board  29   a.    
         [0037]    Each connector duct is formed with a plurality of air holes  30 , and the upper board is formed with a plurality of corresponding pallet openings which are aligned with the air holes  30 , as best seen in FIG. 8. With this configuration, a flow path for air from the forced air source is established through the main air supply duct, connector ducts, through the air holes and pallet openings and into the bin when the composting pallet is placed in the bin. Once the flexible tray is positioned on the bin as described below, and the bin is filled with compostable materials, the forced air infiltrates the material and facilitates the composting process in the bin by aerating the compost  18  therein. Monitoring devices may be incorporated into the air system to allow automatic control of the environment within the compost.  
         [0038]    For the materials of the present invention, and as mentioned above, the bin separation walls are preferably made of flexible plastic or plywood, but other inexpensive materials with similar strength properties for providing structural support could also be used. The main air supply duct can be made from either flexible or rigid material. The connector ducts are preferably made of a plastic material such as polyvinyl chloride (PVC), although other similar types of materials with high strength-to-weight ratios are also envisioned.  
         [0039]    As illustrated in FIG. 1, the tray emptying device  15  is “in front” of a selected bin  16  scheduled for unloading, depending on how one chooses to designate the “front” and “back” of a bin. Because each tray emptying device is costly, it is advantageous to have a single tray emptying device that can service an array of bins  16  as illustrated in FIG. 1. This can be accomplished either by moving the tray emptying device to a destination bin, moving the bin array with respect to the tray emptying device  15 , or moving both the bin and the emptying device.  
         [0040]    However, embodiments are envisioned wherein the aeration system is embedded in concrete below the respective bins, or, at the very least, affixed to the ground. The network of aeration and piping tends to make the bin array less mobile, and the prospect of moving a bin array problematic. According to the preferred embodiment, therefore, the array of bins remains fixed while the tray emptying device  15  transits from bin to bin. Transiting the tray emptying device  15  can be accomplished by any known means, including wheels, raising the tray emptying device  15  by compressed air, fork lifts, jacks and the like. The motion of the tray emptying device can be free, or it can be guided by tracks. The array of bins  16  is preferably a linear array, as illustrated in FIG. 1, thereby facilitating an efficient movement of the tray emptying device  15  from bin to bin.  
         [0041]    Referring now primarily to FIG. 2, the flexible tray  12  comprises a sheet  32  that, when laid flat, is rectangular is shape (other polygonal shapes could also be used) and comprises a mesh portion  34  (which allows air to move into the compost) which is roughly centered on the sheet, and this represents the tray bottom. Preferably, the sheet is made of a reusable high tensile strength material, such as a heavy-duty canvas, or an industrial plastic material. A plurality of lifting eyes  36  are attached to opposite ends  38   a ,  38   b  proximate the corners of the sheet so that the lifting eyes on end  38   a  extend in the opposite direction from the lifting eyes on opposite end  38   b  of the sheet.  
         [0042]    To allow for placement on or removal of the tray from the bin, a respective S-hook  44  is attached to each lifting eye. More specifically, the first end  42  of S-hook  44  is passed through the lifting eye. Second end  46  of each S-hook is then placed in a respective post upright  17  (See FIG. 1) to suspend the flexible tray in the bin. Although not shown in the Figures, another pair of lifting eyes could be located in the transverse center of each end  38   a ,  38   b  of the sheet. Then, once the bin is filled, a belt (not shown) or similar device would connect the two middle lifting eyes to firmly cinch up the filled tray. An alternative would have a plurality of belts (not shown) which would be attached to the lifting eyes on each tray end so that the tray would be separated from any attachment to the post uprights.  
         [0043]    It is to be appreciated that the lifting eye structures could also be attached to the bin separation walls  14 , and that the S-hook could be passed through the lifting eye and the opposite top corners of the bin separation walls could then be hung on the post uprights as recited to “hang” the bin separation walls between a front and rear post upright. This allows for more flexibility in the construction of the system if plywood is not immediately available.  
         [0044]    Flexible tray  12 ′ is shown in FIG. 2A as an alternative embodiment of the invention. Tray  12 ′ includes plurality of longitudinal pockets  47  that are sewn into the sheet. This would allow for use of high tensile strength webbing slings  49  to be threaded through each pocket. Each webbing sling  49  terminates at a pair of opposing webbing eyes  51 .  
         [0045]    To allow for placement on or removal of tray  12 ′ from the bin, a respective support pipe  40  is passed through webbing eyes  51  on each end  38   a ,  38   b  of the sheet so that the support pipe(s) are oriented parallel to and proximate the ends of the sheet. A saddle  53  is placed in each corresponding post upright  17  (See FIG. 10), and the support pipe is placed on a pair of corresponding saddles. In similar fashion to tray  12 , once in place, tray  12 ′ hangs from the support pipes so that the solid end portions define the front and rear walls of the bin and mesh portion  34  defines the floor of the bin.  
         [0046]    As shown in FIGS. 3 and 3A, the system of the present invention includes a plurality of roof joists  80  which can be either portable or fixed. Each roof joist comprises a center arched portion  82  which merges into spaced apart vertical portions  84 ,  84  that are parallel to each other. To temporarily fix the roof joist over a bin, the vertical portions are inserted into corresponding post uprights so that the roof joist is oriented front-to-rear when viewed in top plan and is about co-planar with a bin separation wall.  
         [0047]    Several roof joists may be placed over a bin so that the arched portions have a parallel spaced-apart relationship with each other. A protective bin covering, shown as tarp  88 , can then be placed over the arched portions of the roof joists and attached to tie-down straps (not shown), stakes, bungee cords, or other means known in the art to shelter the compost within the bin. This ensures that the compost in each bin can be protected from wind, sun and rain, which is essential for producing a quality compost. The tarp also provides additional insulation for the compost which ensures proper environmental control of the composting process, especially during cold weather.  
         [0048]    When the tarp is in position over the bin(s), the air space above the compost and below the tarp  88  can be directed via fans (not shown) or other similar means known in the art and passed through a bio-filter (not shown) for control of odors.  
         [0049]    Referring now to FIGS. 1 and 4, the system of the present invention includes a tray emptying device  15  to facilitate offloading of the compost after the composting process is complete. Such tray emptying device comprises a pair of spaced-apart side walls  50 ,  50 . An upper drum roller  52 , supported by an axle  72 , is rotatably mounted between the side walls  50 , so that it rotates freely between trailer walls  50 . Similarly, lower drum roller  54 , supported by axle  76 , is rotatably mounted between the side walls  50 ,  50 . A ramp  56  is positioned between the side walls and is affixed thereto so that leading edge  58  of the ramp is above the lower roller and the trailing edge  60  of the ramp is about even with the bottom portion of the forward vertical edge  90  of the side walls  50 ,  50  which are placed immediately adjacent the post uprights of the particular tray to be unloaded. This arrangement is best seen in FIGS. 4 and 5- 7 .  
         [0050]    A pair of upper cables  62  are spooled around the upper roller  52  and each upper cable terminates at free-hanging upper hook  64 . The lower drum roller  54  does not require cables, as the leading edge of the flexible tray flap closest to the unloading will simply be placed down onto the ramp  56  and be attached to the lower drum roller  54  by inserting the S-hooks or the end of the webbing slings  49 , into slots  94  that are formed in the lower roller.  
         [0051]    Upper motor  70  is coupled to an end of upper axle  72  that extends past the outer surface of a side wall  50  so that selective operation of the upper motor  70  moves the upper axle  72  (and the upper roller  52  that is fixed thereto). Similarly, lower motor  74  is coupled to lower axle  76 , and the lower axle is fixed to lower roller  54 , so that operation of lower motor causes lower roller  54  to selectively rotate as desired. Importantly, upper motor and lower motors are selectively operated independently of each other, and can be further operated at different speeds to allow the respective upper roller and lower roller to rotate as desired for maximum efficiency of bin unloading.  
         [0052]    The number of upper cables (and associated upper hooks) corresponds to the number of S-hooks or eye hooks fixed to a support pipe. Accordingly, it is to be appreciated that one or any other number of upper cables and upper hooks could be used without departing from the scope of the present invention. It is to be further appreciated, that a hand crank  78  (See FIG. 1) or similar means could also be used in lieu of a motor arrangement to operate the upper and lower rollers, either simultaneously or separately, without departing from the scope of the present invention.  
         [0053]    Operation  
         [0054]    Initially, tray  12  (or tray  12 ′) is placed into position by placing S-hooks into the post uprights (or by placing saddles  53  in the post uprights and placing support pole  40  on the saddles) so that the tray and adjacent bin separation walls define a bin as described above. The bin is filled with compostable material via a front loader, feed mix wagon, tilt-bed truck, augers, conveyors, shovels, or other means as known in the art. Air from forced air source  20  is selectively provided to each bin through, in sequence, main air supply duct  22 , connector duct, and into the composting pallet  25  for further passage through airholes  30  and pallet openings  31 . From pallet openings  31 , the air passes through mesh portion  34  and aerates the compost in the bin to thereby facilitate the composting process.  
         [0055]    If necessary, roof joists  80  may be placed over the bin by inserting the respective vertical portions into the post uprights as described above, and a plurality of tarps  88  would be draped over the roof joists  80  to cover all of the filled trays. Such tarp(s) would completely envelop the trays and be secured to the ground on both sides of the bin by tiedowns or similar means known in the art. This ensures the composting process in the bin remains aerobic and the compost therein does not dry out or become overly wet. Because the compost tonnage has been manipulated into smaller, more manageable bin volumes, the composting process occurs more quickly than the high volume composting processes of the prior art.  
         [0056]    Once the compost in a particular bin is ready for offloading, the tray emptying device is placed next to the rear of the bin so that front edges  90  of the side walls  50  contact the post uprights  17  (See FIGS.  5 - 7 ). The rear S-hooks are removed from the post uprights and the rear portion of the tray (the solid portion of the tray that is closest to the tray emptying device) is laid down on the ramp. The S-hooks are inserted into the slots of the lower roller. Simultaneously, the upper hooks are connected to the forward S-hooks of the bin (the S-hooks which are furthest from the tray emptying device), which have been removed from the forward post uprights. This configuration is best seen in FIG. 5.  
         [0057]    The lower motor is operated to rotate the lower roller. When this occurs, the lower roller gathers the rear portion of the tray and the flexible tray becomes wrapped around the lower roller.  
         [0058]    Independently of the operation of the lower motor as described above, the upper motor is selectively operated, When this occurs, the upper cabling becomes spooled around upper roller  52  and moves the upper hooks toward the upper roller. Since the upper hooks are attached to the forward S-hooks, the S-hooks also move toward the upper roller. This causes the forward portion of the tray (the solid portion of the tray furthest from the tray emptying device) to move toward the tray emptying device. This stage of the operation is best seen in FIG. 6.  
         [0059]    The selective operation of the upper motor and lower motor continually shifts the weight of the remaining compost in the bin and positions the remaining compost so that as much of the weight as possible is located on the ramp. This maximizes the mechanical advantage provided by the ramp to move the compost toward the rear of the tray emptying device.  
         [0060]    The net effect of the process is to position as much of the weight of the compost to be offloaded as possible onto the ramp during the offloading process. This is accomplished by simultaneously drawing the both ends of the tray horizontally toward the tray emptying device. This allows the system of the present invention to offload compost more efficiently, and less mechanical work is required to offload the compost from systems of the prior art. Thus, one of the main features of this invention involves the concept of volume reduction to facilitate not only composting, but the unloading/emptying process.  
         [0061]    [0061]FIG. 7 illustrates the operation of the system during the end stages of the offloading process. As shown, the upper hooks are relatively close to the upper roller and the upper cables are almost entirely wound around the upper roller. Because of the flexible nature of the tray, the tray has also substantially wrapped around the lower roller.  
         [0062]    As shown in FIGS. 6 and 7, the compost has been offloaded onto the ground. It is to be appreciated, however, that a conveyor (not shown) or similar device known in the art, could be placed proximate the trailing edge of the ramp. In this way, the compost could be offloaded directly onto the conveyor (or similar device) for packaging and/or further processing.  
         [0063]    Another important feature of this system is the ability to provide mixing capability during the unloading operation. This would occur at a point where there is a ninety degree (90°) change in direction of the flow of compost, from its original direction out of the bin and onto the ramp, to a new direction onto a “take-away” conveyor(s) (not shown) that could be positioned perpendicular to the ramp emptying device. Moreover, the selective operation of the upper and lower rollers described above allows the operator to control the offload rate of compost, thereby allowing for introduction of additive(s) or other materials in a more uniform and controlled manner. This adds greatly to the overall utility/flexibility of the system and produces a more uniform compost product of greater quality.  
         [0064]    While the high volume composting system, as herein shown and disclosed in detail, is fully capable of obtaining the objects and providing the advantages above stated, it is to be understood that the presently preferred embodiments are merely illustrative of the invention and no limitations are intended therefor.