WO2010042700A2

WO2010042700A2 - Aerobic composting apparatus

Info

Publication number: WO2010042700A2
Application number: PCT/US2009/059969
Authority: WO
Inventors: John Hamilton
Original assignee: GLOBAL COMPOSTING TECHNOLOGIES LLC
Current assignee: GLOBAL COMPOSTING TECHNOLOGIES LLC
Priority date: 2008-10-08
Filing date: 2009-10-08
Publication date: 2010-04-15
Anticipated expiration: 2011-04-08
Also published as: WO2010042700A3

Abstract

An in-vessel aerobic composting system is provided. The system includes a composting apparatus and a programmable logic computer. The composting apparatus includes a container, multiple augers, and a floating plate. The augers may rotate clockwise or they can be reversed to rotate counter-clockwise to move the compost material up or down in the vertical direction. The augers are mounted on a support provided at the top portion of the container. The support moves forward and backward along the container during the composting process. The augers are also rotatably mounted on the floating plate. The floating plate holds the augers in an operable position and prevents the augers from bending and breaking without restricting the rotational movement of the augers.

Description

Title: AEROBIC COMPOSTING APPARATUS Inventor: John Hamilton

RELATED APPLICATION

This application claims priority to, and the benefit of, co-pending United States Provisional Application No. 61/103695, filed October 8, 2008, for all subject matter common to both applications. The disclosure of said provisional application is hereby incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a composting apparatus used in aerobic composting of organic waste material.

BACKGROUND

Composting can take the form of the aerobic decomposition of biodegradable organic matter to produce compost. The speed of decomposition of the organic material depends on many factors, including the carbon to nitrogen ratio of the material, the amount of surface area that is exposed to air, aeration (i.e. the amount of oxygen in the pile), the moisture level, the temperature of the material and the outside temperature.

Carbon and nitrogen are two fundamental elements in composting. The bacteria and fungi in compost use carbon as an energy source and nitrogen for protein synthesis. Carbon is considered to be the food and nitrogen the digestive enzyme for the compost. The bulk of the organic matter should be carbon with a sufficient amount of nitrogen to aid the decomposition process. According to present convention, the carbon to nitrogen (C :N) ratio should be roughly 30 parts carbon to 1 part nitrogen (30: 1) by weight. This translates to about 3-4 pounds of nitrogen material for every 100 pounds of carbon for efficient and rapid composting. The composting process slows if there is not enough nitrogen, and too much nitrogen may cause the generation of ammonia gas, which can create unpleasant odors. Leaves are a good source of carbon, while fresh grass, manures, and blood meal are sources of nitrogen.

Decomposition by microorganisms in the compost pile takes place when the particle surfaces are in contact with air. Chopping, shredding, mowing, or breaking up the material increases the surface area of the material to be composted. The increased surface area enables the microorganisms to digest more material, multiply more quickly, and generate more heat. It is not necessary to increase the surface area when composting, but doing so speeds up the process. Insects and earthworms also break down materials into smaller particles that bacteria and fungi can digest.

The decomposition occurring in the compost pile takes up all the available oxygen. Aeration is the replacement of oxygen to the inner portions of the compost pile where it is lacking. Efficient decomposition can only occur if sufficient oxygen is present. This is called aerobic decomposition. Aeration can occur naturally by wind blowing on the compost pile, or when air warmed by the compost process rises through the pile and causes fresh air to be drawn in from the surroundings. Composting systems or structures should incorporate adequate ventilation. Turning the compost pile is an effective means of adding oxygen and brings newly added material into contact with microbes. Turning can be done with a pitchfork or a shovel, or a special tool called an aerator, designed specifically for that purpose. If the compost pile is not aerated, it may produce an odor symptomatic of anaerobic decomposition.

Microorganisms can only use organic molecules if they are dissolved in water, so present convention dictates that the compost pile have a moisture content of 40-60 percent. If the moisture content falls below 40 percent the microbial activity will slow down or become dormant. If the moisture content exceeds 60 percent, aeration is hindered, nutrients are leached out, decomposition slows, and the odor from anaerobic decomposition is emitted. The 'squeeze test' is a good way to determine the moisture content of the composting materials. Squeezing a handful of material should have the moisture content of a well wrung sponge. A pile that is too wet can be corrected by adding dry materials.

Microorganisms generate heat as they decompose organic material. A compost pile with temperatures between 90° and 140⁰F (32° - 6O⁰C) is composting efficiently. Temperatures higher than 140⁰F (60⁰C) inhibit the activity of many of the most important and active organisms in the pile. Given the high temperatures required for rapid composting, the process will inevitably slow during the winter months in cold climates. Compost piles often steam in cold weather. Some microorganisms like cool temperatures and will continue the decomposition process, though at a slower pace.

Conventional batch compost needs to be cured, finished off, and seasoned before use, allowing partly decomposed compost particles to finish the composting process at a low temperature. Earthworms and other invertebrates can assist with this process. The compost must be kept moist and aerated during the curing period. New batches of compost can be produced while curing is taking place giving a constant flow of finished compost. The curing process should take approximately 45 days allowing the compost to finally stabilize. An easy self-test to check the maturity of the compost is to put the compost into a couple of pots and plant some quick growing seeds (radishes are often used because they germinate and visibly grow very quickly) into them. If 75% or more of the seed sprout and grow then the compost is ready to use in any application.

One example of composting is the windrow composting method. In the windrow composting method, the organic waste is formed into rows of piles called windrows. The windrows are aerated by turning the pile periodically by either manual or mechanical means. A pile height of 4 to 8 feet allows for a pile large enough to generate sufficient heat and maintain the temperature within the material yet small enough to allow oxygen to flow to the windrow's core. The optimal pile length is between 14 and 16 feet. The average composting time in the windrow composting is 3 to 6 months. Another example of composting is the aerated static pile method. In aerated static pile composting, organic waste is mixed together in one large pile instead of rows. To aerate the pile, layers of loosely piled bulking agents, e.g. wood, chips, shredded newspaper, are added to the pile to circulate the air from the bottom to the top of the pile. The piles can be placed over a network of pipes that deliver air into the pile or draw air out of the pile. An air blower that is activated by a timer or a temperature sensor may be connected to the pipes. The average composting time in the aerated static pile composting is 3 to 4 weeks, followed by a 30 days of curing period. The ideal waste material to use in the aerated static pile method includes biosolids and sludge.

Yet another example of composting is rotary drum composting. The rotary drum is designed as a continuous feed. The rotary drum takes raw waste in one end and discharges the compost at the other end. The waste material must be ground and mixed with bulking agent prior to being fed to the drum. The rotation of the drum mixes and aerates the compost mix. The material composts for 3 to 5 days in the insulated drum achieving 55-60 ⁰C. During the composting time, odors are collected and biofiltered. The drum provides a solution to odorous wastes. The odors are reduced and pathogen reduction is achieved after the composting step in the rotary drum.

It is also possible to compost waste material in closed reactors, referred as in- vessel composting. Conventional in-vessel composting systems comprise a grated floor for even distribution of air into the composting materials. However, since they lack an internal mechanical mixing mechanism, the compost is not thoroughly aerated from bottom to top.

All of the aforementioned composting techniques require pre-mixing of the waste material for the best performance, and often the waste material is not aerated adequately. For example, current composting systems do not accept high liquid bio- waste without first pre-mixing. Furthermore, most of the composting techniques described above require additional curing time before the compost is finished, thus the product is not ready for immediate use after processing. With some conventional composting systems, mixing augers run in a track fixed to the bottom of the container in order to prevent wear and tear of the upper joints that connect the augers to the upper moving plate. In these composting systems, the augers are fixed to the floor of the container and cannot be lifted for maintenance and/or cleaning. Furthermore, in these systems, a plurality of grooves are provided on the floor of the container to create a track for the augers. The compost material that gets trapped in these groves may slow down the production or break the augers.

SUMMARY

In accordance with one embodiment of the present invention, an aerobic composting apparatus for composting waste material is provided. The aerobic composting apparatus includes a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension. The container is configured to accommodate compost material. The apparatus also includes a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container. The apparatus also includes a rotatable auger mounted on the support beam and extending into the container. The auger rotates around a central axis. The apparatus further includes a floating plate provided proximal to the floor of the container. The rotatable auger mounts to a rotational coupling provided on the floating plate.

In accordance with another embodiment of the present invention, an aerobic composting apparatus for composting waste material is provided. The apparatus includes a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension. The container is configured to accommodate compost material. The apparatus also includes a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container. A reversible rotating auger is mounted on the support beam and extends into the container. The auger is configured to rotate around the central axis in a first direction to pull the compost material up in a vertical direction and the auger is reversible to rotate in a second direction to push the compost material down in the vertical direction. The apparatus further includes a floating plate provided proximal to the floor of the container. The rotatable auger mounts to a rotational coupling provided on the floating plate.

In accordance with another embodiment of the present invention, an aerobic composting apparatus for composting waste material is provided. The apparatus includes a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension. The container is configured to accommodate compost material. The apparatus includes a plurality of holes provided on lower portions of the plurality of walls of the container. The apparatus also includes a humidity controlled air source connected to the plurality of holes via a plurality of connecting pipes. The humidity controlled air source provides humidity controlled air to the internal environment of the container through the plurality of holes. The apparatus further includes a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container. The apparatus also includes a rotatable auger mounted on the support beam and extending into the container. The auger rotates around a central axis. The apparatus further includes a floating plate provided proximal to the floor of the container. The rotatable auger mounts to a rotational coupling provided on the floating plate.

In accordance with another embodiment of the present invention, an aerobic composting apparatus for composting waste material is provided. The apparatus includes a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension. The container is configured to accommodate raw compost material. The apparatus includes a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container. The apparatus also includes a rotatable auger mounted on the support beam and extending into the container, wherein the auger rotates around a central axis. The apparatus further includes a floating plate provided proximal to the floor of the container, wherein the rotatable auger mounts to a rotational coupling provided on the floating plate.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become better understood with reference to the following description and accompanying drawings, wherein:

FIG. 1 illustrates an external view of an in- vessel aerobic composting system comprising a composting apparatus and a humidity controlled air source;

FIG. 2 illustrates a cross-sectional view of the internal environment of the composting apparatus;

FIG. 3 illustrates a close-up view of the bottom portion of the composting apparatus; FIG. 4 illustrates a network of pipes provided at the floor of the composting apparatus;

FIG. 5A illustrates an exemplary mechanism supporting a structure holding augers where the terminal ends of the mechanism extends over the side walls of the container; FIG. 5B illustrates another exemplary mechanism supporting a structure holding augers where the mechanism moves along a track provided on the side walls of the container;

FIG. 6 is a diagrammatic illustration of a composting process; and FIG. 7 is a flowchart illustrating a composting process according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION

An illustrative embodiment of the present invention relates to an in-vessel aerobic composting system. The system includes a composting apparatus and a programmable logic computer (PLC) that controls a number of variables of the composting process, including but not limited to moisture, air volume across the composting mass, mass temperature, and the degree of completion that the mass attains. The composting apparatus is formed of a rectangular container, a plurality of augers, and a floating plate. The augers may rotate clockwise or they can be reversed to rotate counter-clockwise. The augers may move the compost material up or down in the vertical direction, according to the need. The dual rotation of the augers enables thorough mixing of the compost material and improves aeration. The augers are mounted on a support provided at the top portion of the container. The support moves forward and backward along a width of the container during the composting process. The linear speed of the floating plate and the rotational direction of the augers can be controlled with the PLC. The augers are also rotatably mounted on the floating plate. The floating plate does not restrict the rotational movement of the augers, rather the floating plate holds the augers in an operable position and prevents the augers from bending and breaking.

The container of the composting apparatus can be made of plastic, steel, concrete, or a combination thereof. The plastic material prevents the container from rotting or holding mold. Furthermore, the container of the present invention is designed to hold high liquid bio-waste such as sewage, dairy, and/or hog waste without requiring pre-mixing the high liquid waste with solid waste. Due to the dual rotational direction of the augers, the high liquid bio-waste can be mixed with the solid waste inside of the composting apparatus.

Contemporary composting systems can only process premixed composting material. In contrast, the composting system of the present invention is configured to compost premixed composting material (industry standard) as well as non-premixed composting material. The composting material, either premixed or non-premixed, may be in raw form, i.e. as received from the waste stream. The present invention further makes it possible to add amendments within the container, eliminating the need for expensive pre-mixing equipment and physical facilities.

Auger design may vary slightly by industry to accommodate the internal mixing within the container, For example, with high liquid hog manure, a slightly wider ribbon auger may be required to accommodate the necessary lifting action. On the other hand, dead animal composting may require augers with cutting edges, e.g. cutting ribbons, where actual slicing of bone is required. The composting system of the present invention is configured to accept various auger designs required by the industry or the desired composting process.

According to one example embodiment of the present invention, multiple holes are provided on a sidewall of the container of the composting apparatus corresponding to a raised floor. The multiple holes aerate the compost material from beneath. The holes may be connected to an external air blower to supply humidity controlled air to the container. A network of tubes connected to these holes is provided under the raised floor of the container. The tubes may have a perforated, or punctured surface to distribute the humidity controlled air evenly throughout the container floor. A plurality of temperature and moisture sensors provided at different locations within the container relay the temperature and humidity information to the PLC. Based on this information, the PLC determines the amount of humidity controlled air and the level of humidity to be supplied to the contents of the container. Thus, the PLC adjusts the airflow from external air blowers through the compost mass at the required volume.

The composting apparatus of the present invention can aerate the compost mass in three ways: the mass can be aerated from the bottom using the holes of the container, the mass can be aerated within the container using the bi-rotational augers, and/or the mass can be aerated from the top by blowing air or when a lid is not provided.

The entire composting process can be controlled with the PLC. The PLC is a digital computer used for automation of industrial processes, such as control of machinery on factory assembly lines. Unlike general-purpose computers, the PLC is designed for multiple input and output arrangements, extended temperature ranges, immunity to electrical noise, and resistance to vibration and impact. Programs to control machine operation are typically stored in battery-backed or non-volatile memory. The PLC is an example of a real-time system where output results must be produced in response to input conditions within a bounded time, otherwise unintended operation may result. FIGS. 1 through 7, wherein like parts are designated by like reference numerals throughout, illustrate an exemplary embodiment of an aerobic composting apparatus in accordance with the present invention. Although the present invention will be described with reference to the example embodiment illustrated in the figures, it should be understood that many alternative forms can embody the present invention. One of ordinary skill in the art will additionally appreciate different ways to alter the parameters of the embodiment disclosed, such as the size, shape, or type of elements or materials, in a manner to conform with the spirit and scope of the present invention.

FIG. 1 illustrates an external view of an in-vessel aerobic composting system

100 formed of a composting apparatus 120 (see FIG. 2) and a humidity controlled air source 130. The composting apparatus 120 includes a container 102, a pair of rotatable augers 104, such as ribbon screw augers, mounted on a support beam 108 at the top, and a floating plate 1 10 at the bottom. According to an exemplary embodiment of the present invention, a column 105 (see FIG. 2) extending vertically between the augers 104 may also be mounted to the support beam 108 on top and to the floating plate 110 at the bottom. The column 105 increases the rigidity of the auger 104 and support beam 108 structure. The column 105 can take the form of a wing or a truss structure. The support beam 108 moves laterally along a length of the container 102. The floating plate 1 10 moves with the support beam 108 along the length of the container 102, above a raised flooring system 114. The flooring system 1 14 includes a plate that has openings, such as slits, holes and/or perforations, to allow the humidity controlled air to pass through. The flooring system 114 is provided at about twenty-four inches above a floor 103c of the container 102. A plurality of holes 124 are provided on the lower sides of the container 102. The holes 124 are connected to the humidity controlled air source 130 to provide humidity controlled air to the internal environment of the container 102 on an as needed basis. The holes 124 are provided below the flooring system 1 14. The present invention supplies humidity controlled air from the bottom of the container 102. The humidity controlled air then diffuses through the contents of the container 102.

FIG. 2 illustrates a cross-sectional view of the internal environment of the composting apparatus 120. As illustrated in FIG. 2, an agitator mechanism 1 16 enables the support beam 108 to move along the length of the container. The support beam 108 can support multiple augers 104 at one time. According to various embodiments of the present invention, the user may add or remove augers 104 to/from the support beam 108 according to the need. Each auger 104 rotates around a central axis 106 clockwise to move the composting mass upwards and may be reversed to rotate counterclockwise and move the composting mass downward in the container. One of ordinary skill in the art will appreciate that the auger blade angles can be inverted, thus causing the opposite action (e.g. clockwise to move the composting mass upward). As further illustrated in FIG. 2, the flooring system 114 keeps the compost mass away from the floor 103c of the container 102, enabling air to pass through the holes 124 provided at the lower end of the side walls 103a- 103b of the container. According to various embodiments of the present invention, a network of tubes can be provided below the raised flooring system 1 14 to evenly distribute the humidity controlled air coming from the holes 124 to the internal environment of the container 102.

FIG. 3 provides a close-up view of the bottom portion of the container 102. As illustrated in FIG. 3, two augers 104 are rotatably mounted to a pair of mounting points 112 provided on the floating plate 110. According to various embodiments of the present invention, the floating plate 110 may be provided with at least one cutting edge. The floating plate 1 10 stabilizes the augers 104 without affixing them to the floor 103c of the container 102, Accordingly, the floating plate 1 10 eliminates the need to provide tracks and/or bottom fixed housings on the floor 103c of the container 102. As such, the collection and compression of effluent in tracks and/or bottom fixed housings is prevented. The floating plate 1 10 passes about 3/8 inches above the floor 103c of the container 102. The floating plate 1 10 also prevents the accumulation of compacted effluent directly above the air infusion system provided below the flooring system 1 14. The floating plate 1 10 further stabilizes the entire auger system, including the augers 104, the central axis 105, and the support beam 108, within the container 102. Since the augers 104 are not fixed to the floor 103 c of the container 102, the augers 104 may be raised out of the container 102, along with the floating plate 110, for maintenance and/or cleaning. FIG. 4 illustrates the network of pipes provided at the floor 103c of the container 102. A plurality of pipes 132 are connected to the plurality of holes 124 provided at the lower ends of the side walls 103a- 103b of the container 102. The holes are connected to the humidity controlled air source 130 via a plurality of connecting pipes 126 and 128 on the outside of the composting apparatus 120. The plurality of pipes 132 form a network of pipes that is positioned below the raised flooring system 114. The pipes 132 are provided with a plurality of openings 134, such as holes, perforations and/or slits on a surface of each pipe 132 to allow the humidity controlled air to pass through. As such, the humidity controlled air is supplied to the contents of the container 102 from the bottom. The humidity controlled air then travels through the compost mass from bottom to top, distributing the oxygen and humidity evenly throughout the mass. According to various embodiments of the present invention, the network of pipes may be connected to a plurality of humidity controlled air sources, e.g., the network of pipes may be connected to a first humidity controlled air source on one side of the container, and to a second humidity controlled air source on the other side of the container. One of ordinary skill in the art will appreciate that various levels of humidity may be desired for a particular compositing process. The present invention is capable of providing air having all such desired levels of humidity as needed.

According to another embodiment of the present invention, the pipes 124 provided below the flooring system 1 14 may be connected to each other, thus eliminating the need to provide a plurality of holes 124 on the side walls 103a- 103b of the container 102. A single hole 124 may be connected to a first pipe 132 which is connected to the rest of the pipes in the network of pipes. Thus, a single hole-pipe combination may provide the humidity controlled air to the internal environment of the container 102. The humidity controlled air may then be distributed through the network of pipes. One of ordinary skill in the art will additionally appreciate different ways to configure the network of pipes disclosed herein in a manner to conform with the spirit and scope of the present invention.

FIG. 5A illustrates the agitator mechanism 1 16 according to an exemplary embodiment of the present invention. The agitator mechanism 1 16 can include a power source 122, a motor 121 and the support beam 108. The power source 122 supplies power to the motor 121 as needed. The motor 121 puts the augers 104 and the support beam 108 in motion. The terminal ends 1 18a and 118b of the support beam 108 extend over the side walls 103a and 103b of the container 102. The terminal ends 118a and 118b may include a sprocketed roller that meshes with and moves on a sprocketed rail provided on the outer surface of the container's side walls 103a and 103b. The agitator mechanism 1 16 is configured to move along the width of the container 102 in a forward and backward direction. The supporting beam 108 and the augers 104 attached to the support beam 108 move along with the agitator mechanism 116 when the latter is moving along the width of the container 102. For example, according to an exemplary embodiment of the present invention, the agitator mechanism 1 16 completes one pass in each direction in 24 hours. Other frequencies of pass completion are achievable with the present invention, as would be understood by those of ordinary skill in the art.

FIG. 5B illustrates the agitator mechanism 1 17 according to another exemplary embodiment of the present invention. Similar to the agitator mechanism 1 16 illustrated in FIG. 5A, the agitator mechanism 1 17 of the present figure includes a power source 122, a motor 121, and the support beam 108. The power source 122 supplies power to the motor 121 as needed. The motor 121 puts the augers 104 and the support beam 108 in motion. The agitator mechanism 1 17 is further supported by a horizontal beam 1 19 that is connected to the support beam 108. Terminal ends 1 19a and 1 19b of the horizontal beam 119 move along tracks provided on a top surface of the side walls 103a and 103b of the container 102. The terminal ends 1 19a and 1 19b comprise a gear-like end piece that moves on the top surface of the container's side walls 103a and 103b. The agitator mechanism 117 is configured to move along the width of the container 102 in a forward and backward direction. The supporting beam 108 and the augers 104 attached to the support beam 108 move along with the agitator mechanism 1 17 when the latter is moving along the width of the container 102. For example, according to an exemplary embodiment of the present invention, the agitator mechanism 1 17 completes one pass in each direction in 24 hours. Other frequencies of pass completion are achievable with the present invention, as would be understood by those of ordinary skill in the art. FIG. 6 generally illustrates operational aspects of the composting system as described herein in accordance with the present invention. The composting system includes the composting apparatus 120, the humidity controlled air source 130 and the control mechanism PLC 150. The PLC 150 controls numerous variables of the composting process, including but not limited to moisture, air volume across the comporting mass, mass temperature and the degree of completion that the mass attains. Generally, anticipated ranges for these variables include a moisture range of 62%-68%, an air volume range of 8%-12% O₂, and a mass temperature range of 150°F-165°F. Humidity controlled air 160 having a desired level of humidity is provided beneath the flooring system 114, above the floor 103 c of the container 102. The humidity controlled air 160 travels from the bottom of the container 102 toward the top of the container 102 as illustrated by the plurality of arrows 162. The augers rotate in a first direction 156 around a central axis. The augers are configured to be reversible to rotate in a second direction, 158, opposite to the first direction, around the central axis. The augers may move the compost material up or down in the vertical direction, according to the need. The dual rotation of the augers enables thorough mixing of the compost material and improves aeration. The support carrying the augers 104 moves in a first direction 152 and is configured to move in the second direction 154 along the length of the container 102 during the composting process, The linear speed of the sliding plate and the rotational direction of the augers can be controlled with the PLC.

FIG. 7 is a flowchart illustrating a composting process according to an exemplary embodiment of the present invention. The ingredients for the compost are added to the container: a carbon source (step 300), a porosity source (step 302) and the waste stream (step 304) are added to the container. If there are additional ingredients, they are added as well (step 306). Adding additional ingredients is an optional step, as illustrated with dotted lines on FIG. 7. Upon providing all the desired compost ingredients in the container, humidity controlled air is provided to the container (step 308). The agitator mechanism is activated to mix ingredients forming the compost mass using the rotatable augers 104 (step 310). Humidity, temperature, auger speed, and auger rotational direction of the composting apparatus are monitored throughout the entire process (step 312). At the end of the composting process, the finished compost is removed from the container (step 314).

As presented above, the composting apparatus 120 described herein does not require pre-mixing the ingredients of the compost. Using the composting apparatus described herein, all compost ingredients may be placed in the container at the beginning of the composting process. The present invention also eliminates the need to mix additional ingredients to the compost, such as sugar, during the composting process. By controlling the rotational direction, rotational speed and the horizontal speed of the augers, it is possible to mix all ingredients, including but not limited to ingredients that are 90% liquid, at the start of the composting process.

In order to encourage the proper thermophylic bacteria to thrive within the mass, the ratio of Carbon to Nitrogen (C/N), the moisture, and the temperature must be controlled throughout the composting process. A variety of soil conditioners, e.g. soil amendments, may be used to provide a correct "recipe" for the compost. After the recipe is determined, the soil amendments and the composting effluent are loaded into the container according to either a weight or volume measure. Normally the carbon source, e.g. straw, paper, etc., is loaded first, then the porosity amendment, e.g. peat moss, compost from an earlier batch, etc., and finally the high liquid waste stream are loaded. However, the order in which the ingredients are added may be altered. The augers are then controlled to mix the mass.

Moisture is one of the key variables of the composting process. When the conditions are too wet or too dry, the thermophylic bacteria may die without accomplishing their task. The composting system according to the present invention introduces water in the form of hyper-humidity controlled air from beneath the compost mass. The air across the compost mass carries the moisture from the bottom to the top of the compost mass. Thus, the present invention eliminates the need to add water to the top of the compost mass for the water to seep as far down as it can before it is completely absorbed by the dry material. According to the present invention, critical material at the bottom is moistened evenly and constantly moved from bottom to top and top to bottom via the variable speed, reversible direction augers. Furthermore, since the present system does not require adding water, it does not require removing excess liquid from the container. Excess liquid is the result of improper pre-mixing. Material that is too wet will leach liquid to the bottom and pool. This leachate that contains all of the harmful pathogens that the composting process is used to eradicate must then be drained. However, by eliminating pre-mixing and watering during the composting, the present invention eliminates the need for liquid removal by eliminating the excess liquid to pool at the bottom of the container.

An exemplary method of operation of the present invention is provided on FIG. 8. A composting process may start with adding the carbon source ingredients to the container (step 300). Porosity source ingredients are added next (step 302). Waste stream ingredients are added to the container last (step 304). If the composting process requires additional ingredients, they can be added during the optional step 306. The sequence in which the ingredients are added may be changed according to various composting processes. The sequence illustrated herein is for illustrative purposes and should not be construed as limiting. Once all the ingredients are added to the container, humidity controlled air is provided to the internal environment of the container from beneath (step 308). The composting mass is continuously mixed with the rotating augers (step 310). As described above, the rotation direction, rotating speed and the moving speed of the augers can be controlled using the PLC throughout the entire composting process (step 312). The PLC also controls the humidity and the temperature inside the container (step 312). After necessary time passes, the compost is ready and can be removed from the container without requiring a curing process (step 314).

The finished compost from this invention is free from eColi bacteria not only because the dangerous bacteria may be killed by the temperature increase during the process but also because the present invention eliminates the food source required by the dangerous bacteria during the process. The composting process described herein generates a finished material that contains no residual food source for dangerous bacteria. The finished compost may be safely stored outside without a risk of reinfection or runoff. The present invention may be utilized in with the following exemplary composting process. The exemplary process is provided for illustrative purposes only, and should not be construed as limiting. The present invention may be used with a variety of compost ingredients and composting periods.

An exemplary cattle manure compost may require 70% raw manure by volume, 20% straw (or any carbon source) by volume and 10% peat moss (or any porosity source) by volume. First the straw is added to the container, then the peat moss, and finally the raw manure are added to the container. Humidity controlled air is provided inside the container and the variable speed augers start mixing the batch. The compost process initiates when the moisture inside the container is approximately at 65%. The humidity controlled air continually passes across the mass from the bottom. The temperature and oxygen are then continuously monitored and controlled to be within a desired range, e.g., an air volume range of 8%-12% O₂ and a mass temperature range of 15O⁰F- 165⁰F, until a natural decline in both occurs generally after about 14 days. Within twenty-four hours, the thermophylic colonies begin to multiply and their exothermic activity produces heat. A temperature between 50 to 60 degrees Celsius is attained in the first two days. The augers pass back and forth folding and aerating the mass twice daily. By day 10, the ingredients break down to the point that the mix looks like soil. Over the next 10 to 12 days, the thermophylic colonies begin to starve out and the temperature begins a steady decline to ambient. At the end of the composting process, the thermophylic colonies have consumed all dangerous pathogens and the compost is completed. The compost may be placed out in the rain and the dangerous pathogens will not reappear.

When there is a need for a large volume of effluent to be handled at a single unit, multiple containers according to the present invention may be placed in a metal building. An air system is attached to the building and the augers are lowered into the building to start the composting process. The augers are removed at the end of the process. The containers can then be removed by truck and moved to a suitable site.

Numerous modifications and alternative embodiments of the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode for carrying out the present invention. Details of the structure may vary substantially without departing from the spirit of the invention, and exclusive use of all modifications that come within the scope of the appended claims is reserved.

Claims

CLAIMSWhat is claimed is:

1. An aerobic composting apparatus for composting waste material, the apparatus comprising: a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension, wherein the container is configured to accommodate compost material; a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container; a rotatable auger mounted on the support beam and extending into the container, wherein the auger rotates around a central axis; and a floating plate provided proximal to the floor of the container, wherein the rotatable auger mounts to a rotational coupling provided on the floating plate.

2. The composting apparatus of claim 1, further comprising at least two augers.

3. The composting apparatus of claim 1, wherein the auger is provided with a cutting edge.

4. The composting apparatus of claim 1 , further comprising: a plurality of holes provided on one or more walls of the container, proximal to the floor of the container, wherein the plurality of holes provide humidity controlled air to the internal environment of the container.

5. The composting apparatus of claim 4, further comprising: a plurality of tubes connected to the plurality of holes, wherein the tubes extend through the floor of the container, the tubes comprising a plurality of openings to distribute humidity controlled air coming through the plurality of the holes to the internal environment of the container.

6. The composting apparatus of claim 4, wherein an amount of the humidity controlled air provided to the internal environment of the container is controlled using a programmable logic computer.

7. The composting apparatus of claim 4, further comprising: a humidity controlled air blower connected to the plurality of holes for providing humidity controlled air to the internal environment of the container.

8. The composting apparatus of claim 1, further comprising: a lid for covering a top portion of the container to prevent odors from mixing with a surrounding area of the container.

9. The composting apparatus of claim 1, wherein the auger is configured to rotate around the central axis in a first direction to pull the compost material up in a vertical direction and the auger is reversible to rotate in a second direction to push the compost material down in the vertical direction.

10. The composting apparatus of claim 1, further comprising: an agitator mechanism incorporating the support beam, the agitator mechanism comprising: a pair of gears provided at each terminal end of the support beam; a power source that supplies the agitator mechanism; and a motor that motivates the agitator mechanism.

1 1. The composting apparatus of claim 1 , wherein the support beam is configured to move in a forward horizontal direction or in a backward horizontal direction.

12. The composting apparatus of claim 1 , wherein rotational direction of the auger and a speed of the moving support beam is controlled using a programmable logic computer.

13. The composting apparatus of claim 1, wherein the container is rectangular.

14. The composting apparatus of claim 1, wherein the container is made of plastic, steel, concrete or a combination thereof.

15. The composting apparatus of claim 1 , further comprising: a door disposed on one wall of the container to provide access to the internal environment of the container.

16. The composting apparatus of claim 1 , further comprising: one or more humidity sensors provided inside the container at a plurality of locations, wherein the one or more humidity sensors measure a humidity level of contents of the container.

17. The composting apparatus of claim 1 , further comprising: one or more oxygen sensors provided inside the container at a plurality of locations, wherein the one or more oxygen sensors measure an oxygen level of contents of the container.

18. The composting apparatus of claim 1 , wherein the container is configured to compost non-premixed high liquid waste material comprising raw sewage, dairy, hog waste or a combination thereof.

19. The composting apparatus of claim 1 , wherein the container is configured to compost non-premixed dead livestock.

20. The composting apparatus of claim 1 , further comprising: a vertical column mounted to the support beam at top and to the floating plate at the bottom, wherein the vertical column increases a structural stability of the rotatable auger.

21. An aerobic composting apparatus for composting waste material, the apparatus comprising: a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension, wherein the container is configured to accommodate compost material; a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container; a reversible rotating auger mounted on the support beam and extending into the container, wherein the auger is configured to rotate around the central axis in a first direction to pull the compost material up in a vertical direction and the auger is reversible to rotate in a second direction to push the compost material down in the vertical direction; and a floating plate provided proximal to the floor of the container, wherein the rotatable auger mounts to a rotational coupling provided on the floating plate.

22. An aerobic composting apparatus for composting waste material, the apparatus comprising: a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension, wherein the container is configured to accommodate compost material; a plurality of holes provided on lower portions of the plurality of walls of the container; a humidity controlled air source connected to the plurality of holes via a plurality of connecting pipes, wherein the humidity controlled air source provides humidity controlled air to the internal environment of the container through the plurality of holes; a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container; a rotatable auger mounted on the support beam and extending into the container, wherein the auger rotates around a central axis; and a floating plate provided proximal to the floor of the container, wherein the rotatable auger mounts to a rotational coupling provided on the floating plate.

23. An aerobic composting apparatus for composting waste material, the apparatus comprising: a container formed of a plurality of walls and a floor defining an internal environment therein and having a width dimension, a length dimension, and a height dimension, wherein the container is configured to accommodate non-premixed compost material; a support beam extending across a top portion of the container along the width dimension and movable along the length dimension of the container; a rotatable auger mounted on the support beam and extending into the container, wherein the auger rotates around a central axis; and a floating plate provided proximal to the floor of the container, wherein the rotatable auger mounts to a rotational coupling provided on the floating plate.