LT4400B - Compost curing and odor control system - Google Patents

Abstract

The system for managing the fermentation and smell of compost, according to which the biological filters are placed above the area of compost fermentation, the basis of the fermentation area and biological filters consists of long, trapezium shaped plates in cross-section, attached to each other by the longer parallel part of the trapezium, which is in the upper plane of the ventilation floor; there must be a gap between these plates; the air is supplied through this gap from the ventilation system air chamber from below.

Description

Field of the Invention

The present invention relates to a method and apparatus for the fermentation of compost and the removal of gas produced at that time. More specifically, the present invention relates to a unique aeration floor design and method of operation that improves and accelerates the process fermentation and degassing phases, and a unique water treatment system.

Preconditions of the invention

Previous fermentation systems generally used a concrete foundation consisting of rectangular trenches with perforated pipes fitted therein, which were fed from a common air chamber. The pipes are covered with a metal or plastic grate or gravel distribution system, which allows the chargers to move across the substrate and regularly rotate the compost. The main problem with such systems is the uneven distribution of air leading to unreliable compost fermentation. Another problem with these systems is the blockage of the floor vents and the system must be stopped before the vents are cleaned. Another problem with clogging the openings is the increase in pressure to the desired airflow. For this reason, a higher capacity fan is required to guarantee optimal fermentation conditions to compensate for the various effects of changing airflow resistance caused by clogging of the aeration vents. These problems cause unnecessary downtime, which increases the cost of production. The present invention overcomes these problems. It should also be noted that the use of the new equipment and production method significantly improves the operation and efficiency of the fermentation process. Air passages are easier to access and clean, and the overall cost of the fermentation system is significantly lower. Another important aspect of the invention is the unique arrangement of system elements. Important factors are the proximity of compost fermentation systems to residential areas and the land area required for these systems. Placing biofilters on top of the fermentation substrate, as discussed above, serves two important purposes. Firstly, it reduces the amount of work required and secondly, the positioning of the filtration system guarantees that the biofilters release gas at higher altitudes and therefore are more distributed in the atmosphere. There is also an innovative system that guarantees gas dispersion in case of atmospheric inversions and saves and retains water.

Summary of the Invention

The most important part of the invention is the unique floor construction. The aeration cavity consists of a group of concrete elements of generally trapezoidal cross-section. The elements are arranged so that they are in contact with a longer parallel part of the trapezoid located in the upper plane of the ventilation floor. The end of each element rests on a concrete beam. This design results in a thin joint between adjacent elements. A thin circular saw or rake tooth is pulled along the joint line to create a narrow air-permeable crack. The crevice is narrow enough to prevent compost on the floor from falling through it. Underneath the floor are numerous air chambers, which are supplied with air from a common manifold. This arrangement ensures an even distribution of air throughout the system and is essentially non-clogged. The system is easy to maintain without completely interrupting the fermentation process. It has been observed that using the same floor type in a biofiltration system offers the same benefits. In addition, vertical stacking of the fermentation and air filtration components creates a more economical and efficient fermentation and air filtration system. For optimum performance of biological systems, air chambers are converted into oxidation ditches or bodies by partially filling the chamber with water and transferring liquid from biofiltration and compost fermentation units to aeration chambers. This procedure saturates the water with microbial cultures, and the water is then selectively sprayed onto the fermenting compost heaps and the biofiltration medium. In addition, you have used a roof to collect rainwater and cameras as water tanks, creating a unique water management system.

Brief description of the drawings

The foregoing and other features of the invention will be better understood by reference to the following detailed description of the invention, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a side view of an aerated fermentation cavity showing one aspect of the present invention.

FIG. 2A and 2B are cross-sectional views of variations in the construction of floor elements.

FIG. 3 illustrates a compost aeration and odor control system using biofilters above the roof.

FIG. 4 is a side view of parts of a biofiltration system.

FIG. 5 is a schematic view of the air distribution and ventilation network.

FIG. 6 depicts a biofilter exhaust system using fans.

FIG. 7 is an isometric view of a water retention and storage system and a microbial re-injection device using the new invention.

Detailed description

For the purpose of illustrating the invention, the drawings illustrate the presently proposed form; however, it is to be understood that the present invention is not limited to the construction and means shown herein.

Current state-of-the-art and advanced composting systems for solid waste and wastewater sludge utilize one or more horizontal layouts that gradually decompose the material as a result of microbial activity. A tubular utilizer is divided into two or more sections or steps. During the process, the utilizer rotates and passes a controlled amount of air against the direction of movement of the material. The conditions at each step shall be such as to ensure optimal multiplication of the species of micro-organisms present. Representative examples of such systems and working methods are described in U.S. Pat. 3,245,759; and 3,138,447, which are assigned to the author of the present invention, the texts of which are hereby incorporated by reference.

In a composting system using a multi-stage utilizer for the composting of municipal solid waste and sewage sludge, the material is usually retained in the utilizer for three days. The material removed from the utilizer consists of partially fermented compost and non-degraded particles. Partially fermented or green compost is diverted to a further site for composting and fermentation. For the purposes of the present invention, the further processing phase of partially fermented compost will be referred to as fermentation. The term 'fermentation site' as used in the present invention refers to the place where partially fermented compost is converted to humus-like material. The fermentation phase of the composting process is an important and necessary part of the whole process. The present invention is directed first and foremost to this stage of the process and the subsequent purification of the air used in the process before it is discharged to the atmosphere. It is, however, to be understood that the principles of the present invention may be more widely applied than in the embodiments described herein alone; just as it is possible to treat untreated compostable material or to eliminate bad odors and purify the gases from various sources.

With respect to the drawings, and in particular the first of these, it shows a side cross-section of the aeration floor and air supply systems showing a structure of the aeration cavity currently proposed, which reflects one aspect of the present invention. From this drawing, it can be seen that the air floor 10 is made up of a plurality of concrete elements 12. Underneath the floor is an air chamber 14 covered with high density polyethylene, about 0.030 to 0.100 inches thick. The air chamber is at least three feet deep to facilitate service. The air chamber is a post-fermentation site 16, which in the drawing is twenty feet wide (measured perpendicular to the paper plane) and sixty feet long; the fermentation site portion 17 does not contain compost and returns the compost mixing device 18 to its original position. FIG. 2A depicts a cross-sectional view of the proposed design of aeration floor components. FIG. 2A The 8-inch-thick elements have a trapezoidal cross section and a rectangular bottom. The upper surface 20 of the element is 10 to 12 inches wide and the lower surface 21 is 8 to 10 inches wide. The required structural strength is provided by steel reinforced concrete bars 24. The auxiliary components of the aeration floor are in contact with each other as shown in Figs. 2A. At their joints, 1/16-inch-wide slots 26 are formed with a saw or rake tooth. · This procedure is used to form slots with a controlled and uniform width. Thanks to this unique design, the air is distributed evenly, which is essential for efficient fermentation, and the structure itself is strong enough to withstand six to ten feet of compost piles stacked on aeration floors. In addition, these components are robust enough to support a rubber-banded charger, which pushes compost onto the aeration floor when needed. Alternative panel construction is possible, ensuring even air distribution and structural strength. In this embodiment, the core 27 together with the slits 28 play the role of an air conduit.

The aeration channel, made up of thirty 15-foot wide and 60-foot-deep 5 fermentation cavities, in which compost is stacked in 10-foot-high piles, can hold approximately 5,000 tons of compost. The compost to be fermented 30 is stacked on the fermentation floor. As can be seen from Figs. 1 and 5, air is supplied to individual chamber air chambers 14 through 8-inch-diameter polyvinyl chloride tubes 32 to which air is supplied through a 24-inch-diameter polyvinyl chloride manifold 34 via fans 36 (Fig. 5). Fermentation requires a temperature of 55-65 ° C. Each air supply tube 32 has a computer-controlled damper 38 for controlling air flow. The temperature of each cell is monitored by temperature sensors located in its strategic locations. There are three fans located at each end of the channel to maintain the required airflow in each fermentation channel. At 12,000 cubic feet per minute, each power fan was found to provide the proper conditions for the biodegradation process of the above parameters. This embodiment is illustrated in Figs. Scheme 5. The whole system is controlled by a computer 42.

Each compost aeration cavity utilizes a compost agitator, patented and described in U.S. Patent Application Serial No. 08 / 235,970, filed May 5, 1994, which is incorporated herein by reference and is incorporated herein by reference. The mixing device 18 (Fig. 1) described in that patent is movably suspended over a compost pile using a bridge crane mounted on a balustrade or truss structure 44. The crane thus mounted can move along the entire length of the pile, and the mixing device mounted on the carriage 48 can move balk along the entire pile. The compost mixer is usually a V-shaped structure, with one branch consisting of a pair of opposing rotary belt screws 50 and another branch in front of it, consisting of a coupled conveyor system not shown in the drawing. The rotary adjustment of the belt screws and the conveyor and the adjustment of the connection with the support system allow the mixer to be used for mixing compost heaps of different heights and can leave different spacing between the mixed and non-mixed compost heaps. After approximately four weeks in the aeration cavity, the compost is pushed out of the aeration cavity by an automatic mixer.

FIG. 3 shows a vertical cross-section of the biofilters constructed in accordance with the present invention. 5 The construction of the top floor floor 52 is identical to that of the aeration fermentation floor shown in FIGS. 1. It also has an air chamber 54 which is similar to a fermentation chamber and is located below the floor of a biofilter. Alternatively, an air floor could be used using the panels shown in FIGS. 2B, and air cameras would become obsolete. Through vent pipe 56 and air pump

58 gas from the fermentation floor is fed into the air chamber. The gas passes through biofilters that eliminate bad gas odor. To ensure poor odor control, the filter medium 60 is automatically and periodically agitated and agitated by a mixer 62. The mixer is of conventional design consisting of a plurality of blades 64 mounted on a common axis as shown in FIG. 4. A mixer mounted on a trolley (not shown) moving on rails 66. It is understood that biofilters of the type shown may be extensively suited for general odor control, not only for treatment and odor control of municipal solid waste and sewage sludge. The use of an automatic agitator in conjunction with this design ensures continuous periodic movement of the biofilter media through the biofilter channels. This automatic biofilter media mixing ensures constant media regeneration, constant biofilter resistance to airflow, media porosity and filtration productivity.

During transverse displacement in the channel, the filter medium is shifted 6 to 8 feet toward the exhaust end. At the end of each transverse shift, the agitator is moved onto an automatic transfer trolley (not shown), which moves it to the next passage to repeat the cycle. The length of each duct is determined by the specific air handling requirements. Mixers of this type are well known in prior art.

After the fermented compost is pushed out of the fermentation cavity, it is sifted into several groups. The portion that passes through the sieve is used to replenish the biofiltration medium 60 and is introduced into the biofiltration system at the point where the compost is discharged from the aeration fermentation cavity. Using this method, the nasty gas produced in the fermentation cavity is filtered by the most mature and finest filtration medium, thereby achieving a more efficient filtration of the gas formed.

Mixer 62 shifts the filtering biotope in the opposite direction to the compost movement on the aeration floor, and the biofilter medium passes through its channel within approximately 12 weeks. At the exhaust end of the biofiltration system, the spent medium is removed, foreign matter is sifted, and the medium is used to balance the aeration fermentation cycle. This way much less material gets into the trash.

In cases where the air temperature at different altitudes of the atmosphere is stratified, so-called thermal inversion occurs, whereby the air at the surface of the earth is held pressurized with the pollutants it contains. To solve this problem, a new construction is used, shown in Figs. 6, which utilizes a fan 70. The effectiveness of this design is enhanced by the venturi tubular stack 72, which directs air approximately as shown in that drawing. The fan can diffuse filtered air even up to 700 feet - far higher than normal inversion heights - and it produces much less polluting work, even in the worst weather conditions. To achieve the desired result, every 10,000 square feet of biofilter surface requires an 18-foot diameter fan with an output of 850,000 cubic feet / min. The fan dilutes the air in a ratio of 10: 1 around its blades, and the diluted air is discharged through the inverse layer to a height of 700 feet. The system obtains wind speeds of 40 to 50 mph in the fan plane. Venturi can be used for even higher speeds and operating efficiency. In the absence of temperature inversion in the atmosphere, gas dissipation. Roof biofilters are operating satisfactorily. In this case, the fans can be brought into operation to dilute the scent and displace it above the inversion layer for further dilution and dispersion. The fabric curtain covering the biofilter area can be used to collect all the gases evolved.

FIG. Figure 7 illustrates another aspect of the invention - a water management system that improves and accelerates the fermentation process, reduces or eliminates the possibility of liquid leaking from the composting system and the need to buy water from elsewhere, saving water and allowing local rainwater storage to be met.

In the biofilters and on the aeration floor, the liquid 5 produced in the fermented compost is collected and stored in the air chambers below. In this way, the liquid that can enter the groundwater is collected and returned to the composting process. The biofilter medium fluid passes through the conduit 74 into the aeration chamber air chambers 14 where it is mixed with rainwater collected on the roof 76 and becomes an oxidizing deposit utilizing microbial cultures for treatment and purification purposes. The culture, in the form of a solution, is fed through a pump 78, piping 80 and valves 82 to sprinklers 84, which distribute the liquid onto the fermentable compost and the filtering biota. This procedure improves and accelerates the ongoing biological process. The water 86 held in the air chambers is heated by blowing air through the pipe 88. The nozzles 90 move the water and make it move around the septum 91 in the center of the chamber. This action heats and moves the water, accelerates microbial growth and prevents the water from settling.

As mentioned above, underground aeration chambers serve as oxidation ponds and as incubators for microbial cultures, which are then dispersed in biofiltration media and compost. Fans not shown in the drawing blow air into the solution accumulated in the chambers, heating it and causing a weak current. The air nozzle 90 is flexibly mounted on a float 93 floating on the surface of the solution. When needed, sprayers 84 spray microbial cultures propagated on compost and filter media in the oxidation pond. A wall 96 is provided at both ends of the roof or overlay 76, which, together with the partitions 98 driving the biofilter mixer, forms a water collection area. For better water retention, the roof can be covered with a waterproof roofing material such as high density polyethylene.

The water falling from the roof can be directed to the storm sewer or via valve 100 and associated piping 102, schematically illustrated in FIG. 7, can be directed to air chambers under the aeration floor 14. The aeration system described above consists of 30 aeration cavities, each having an air chamber 15 feet wide, 60 feet long, and 3 to 6 feet deep, capable of holding more than one million gallons of water. . If there is excess rainwater, as happens in the summer months in Florida, water may be drained from the system via valve 104.

In conclusion, the new floor design of the aeration and biofilter systems 5 guarantees an even and predictable distribution of airflow, a necessary and hitherto unattainable goal for efficient and economical fermentation of compost and removal of bad odor of gas. In addition, the innovative arrangement of biofilters above the aeration floor saves space and disperses the resulting gas more widely in the atmosphere. Such a dual design eliminates the need for any air pipeline, which in turn reduces heat losses in such pipelines and lowers the cost of running biofiltration systems. Such a structure retains the aeration floor heat, protecting it from freezing, which is especially true in cold climates. Finally, utilizing roof construction and cavities under aerated floors as water reservoirs and oxidation ponds, an innovative system of water management and microbial return to compost and biofiltration media is being implemented.

It will be understood that different conditions will require structural and dimensional changes other than those set forth herein and in the accompanying drawings, and that the invention itself may be embodied in other specific forms without departing from the spirit and essential features and, accordingly, the scope of the invention; in this case, reference should be made to the attached patent claims and not to the above specifications.

Claims (19)

Definition of the Invention 1. A compost fermentation system consisting of a floor for the storage of partially fermented compost, characterized in that 5 consisting of a plurality of multi-wall panels of generally trapezoidal cross-section with their longitudinal parallel sides lying flat on the floor; said slabs being separated from each other by slits approximately 1/16 inch (1.59 mm) wide and forming open grooves generally triangular in shape below the floor surface; in addition, it has an underground air chamber communicating with 10 with said grooves and wherein said floor forms an upper surface; and having means for supplying compressed air exiting said grooves to said chamber. Compost fermentation system according to claim 1, characterized in that it has partially fermented compost on said fermentation floor and means, 15 automatically and periodically mixing said compost. 3. Compost fermentation system according to claim 2, characterized in that it comprises means comprising said system. 4. A compost fermentation system according to claim 3, characterized in that it has a gas collection and 20 distribution through biofilters above the fermentation floor. 5. A compost fermentation system according to claim 4, characterized in that the biofilter has a floor structure consisting of a plurality of multi-wall panels, usually of trapezoidal cross-section, with their long parallel sides lying in the floor plane; said boards separated from one another 25 slots approximately 1/16 inch (1.59 mm) wide and form a series of mostly triangular open grooves below the floor surface. 6. A compost fermentation system according to claim 5, characterized by having means for periodically and automatically agitating the biofilter medium. 7. A compost fermentation system according to claim 6, characterized in that it has a greenhouse which covers said biofilter and mixing means and has valves for venting the biofilter gas. 8. A compost fermentation system according to claim 7, characterized in that it has means located above said biofilter for extracting the gases emitted from the biofilter and distributing them at a higher atmospheric altitude. 9. The compost fermentation system of claim 11, wherein said gas extraction means comprises a fan. 10. A compost fermentation system according to claim 9, characterized in that it has a hood located between said biofilter and said fan through which the gas emitted from said biofilter must pass. 11. A compost fermentation system according to claim 9, characterized in that said enclosure encloses said fan and has the form of a venturi. 12. A compost fermentation system consisting of a fermentation floor for storing partially fermented compost, characterized in that said floor consists of multi-wall panels with a generally trapezoidal cross-section, the longer parallel sides of which form the upper surface of the floor and the adjacent floor. 15 panels have a plurality of triangular open grooves between them; having a first air chamber under the floor communicating with said grooves and forming said upper surface on said floor; means for supplying compressed air to said first air chamber; means for collecting gas from the fermentation floor; one or more biofilters above the fermentation floor, said biofilters having a floor 20, consisting of a plurality of multi-wall panels of generally trapezoidal cross-section, the longitudinal parallel sides of which lie in the plane of the floor; said slabs being separated from each other by slits approximately 1/16 inch (1.59 mm) wide and forming a series of open grooves generally triangular below the surface of the floor; still has a second air chamber underneath the biofilter floor, 25 wherein said floor forms an upper surface; means for collecting gas from the fermentation floor and feeding it to said second air chamber; means for automatic and periodic mixing of fermentable compost; and means for automatically and periodically agitating the biofilter medium. 13. The compost fermentation system of claim 12, wherein 30 having a greenhouse to cover said biofilter and blending means and having means for discharging gas from said greenhouse into the atmosphere. 14. A compost fermentation system according to claim 12, characterized in that said biofilters are arranged on a roof, the individual parts of which are open to the atmosphere for collecting rainwater. A compost fermentation system according to claim 14, characterized in that it has means for directing a certain amount of collected rainwater to said first air chamber. 16. A compost fermentation system according to claim 15, characterized in that the liquid discharged from said biofilters and collected in said second air chamber is selectively directed to said first air chamber. 10th 17. The compost fermentation system of claim 16, further comprising means for selectively spraying microbial water from the first air chambers onto the fermentable compost and / or biofilter medium. 18. A compost fermentation process that puts fermentable compost on the floor, characterized in that 15 multi-wall elements of mostly trapezoidal cross-section with longer parallel sides forming the aeration floor; the said elements are placed side by side; forms narrow slits between adjacent floor elements; forming, below the floor, an air chamber communicating with said cracks and forming said upper surface on said floor; and providing means for supplying compressed air to said chamber which exits said chamber 20 cracks and compost lying above them. 19. The method of claim 18, further comprising the steps of: collecting a fluid leaking from said fermentable compost in said air chamber; cultivate microbes in the liquid in the chamber and water the fermented compost with this microbial culture. 25 20. A compost fermentation system, characterized in that it comprises an aeration floor having a plurality of cracks on its surface, narrow at the top and extending to a depth; an air chamber below said cracks, said floor forming an upper surface; and means for supplying air to said chamber.