High-humidity and high-viscosity organic solid waste pressure swing vessel fermentation and microorganism nitrogen preservation pilot plant and use method

Abstract

The invention belongs to the technical field of organic solid waste treatment, and particularly relates to a high-humidity and high-viscosity organic solid waste variable-pressure container fermentation and microorganism nitrogen preservation pilot plant and a use method. A bin cover is mounted at the top of the fermentation bin; a leachate storage chamber is arranged at the bottom of the fermentation bin; the leachate storage chamber is communicated with the fermentation bin; a porous circular plate is fixedly mounted between the leachate storage chamber and the fermentation bin; a plurality of air walls are arranged above the porous circular plate; each air wall is composed of two porous rectangular plates; an air inlet of the air pump is positioned above the air pump; an air outlet pipe of the air pump extends downwards from the contact center position of the plurality of air walls, penetrates through the porous circular plate and extends into the percolate storage chamber; a microwave heating unit is mounted in the percolate storage chamber; by arranging the fermentation bin, the aerobic decomposition efficiency of organic solid waste can be improved, the fermentation period is shortened, and the overall fermentation efficiency and the nitrogen content in a fermented product are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of organic solid waste treatment, and specifically relates to a high-humidity and high-viscosity organic solid waste pressure-changing container fermentation and microbial nitrogen preservation pilot plant and a use method thereof. Background Art

[0002] my country's high-humidity and high-viscosity organic solid waste includes urban sludge, kitchen waste three-phase organic solid residue, etc., which have large output and wide application fields. After treatment, urban sludge and kitchen waste three-phase organic solid residue can be made into organic fertilizer rich in nitrogen, phosphorus, potassium and various trace elements, which can improve soil structure, increase soil fertility and water retention, and promote crop growth.

[0003] This type of organic solid waste has a small particle size (<2mm) and is in the form of flour. During the treatment process, oxygen diffusion is easily blocked and local hypoxia occurs, which in turn inhibits the decomposition ability of microorganisms, prolongs the fermentation cycle, and reduces fermentation efficiency. To alleviate the problem of insufficient oxygen, a common practice is to improve the oxygen supply by increasing the air flow. However, this method usually uses continuous ventilation. Although it alleviates the oxygen problem to a certain extent, it leads to increased water loss, thereby reducing the moisture content of the fermented material to a level that is not conducive to the survival of microorganisms. Therefore, atmospheric pressure aerobic fermentation technology faces a contradiction between water and oxygen supply in actual applications, which not only prolongs the fermentation cycle, but also leads to a low degree of maturity, thus affecting the quality and application value of the final product.

[0004] To solve this problem, a study has proposed an efficient humification method for kitchen waste solid residue based on the fermentation process of a pressure-swing container (202311013828.6), which can effectively alleviate the contradiction between water and oxygen. However, during the pilot pressure-swing container fermentation process, the materials in the central area of ​​the fermentation bin still have the problem of insufficient oxygen supply. In particular, as the size of the pressure-swing container increases, this problem of limited oxygen mass transfer becomes more and more significant, resulting in the inability of microorganisms on the surface of some fermented materials to obtain sufficient oxygen, resulting in anaerobic reactions in local areas. This situation will not only produce harmful gases and reduce the quality of compost, but may also increase processing costs and the risk of disease transmission, seriously affecting the composting effect and environmental safety.

[0005] In addition, since the atmospheric pressure aerobic fermentation technology uses continuous ventilation, during the fermentation process, the ammonia produced by the decomposition of protein in the organic solid waste will be discharged with the ventilation and become part of the odor; this not only increases the burden of subsequent odor treatment, but also leads to the loss of nitrogen, thereby reducing the fertility of the fermented material and affecting the quality of the final product and the benefits of agricultural application. Summary of the invention

[0006] In order to make up for the deficiencies of the prior art and solve the above-mentioned technical problems, the present invention proposes a pilot-scale device for fermenting high-humidity and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen, as well as a method for using the same. By setting up a fermentation chamber, the present invention can improve the aerobic decomposition efficiency of organic solid waste, shorten the fermentation cycle, and improve the overall fermentation efficiency. The specific structure is as follows: A pilot-scale device for fermenting high-humidity and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen, comprising a fermentation chamber; A lid is installed on the top of the fermentation chamber; a leachate storage chamber is provided at the bottom of the fermentation chamber; the leachate storage chamber is communicated with the fermentation chamber; A porous circular plate is fixedly installed between the leachate storage chamber and the fermentation chamber, and the aperture of the holes on the porous circular plate is 2-3 mm; a plurality of air walls are arranged above the porous circular plate; the inner cavity of the fermentation chamber is divided into a plurality of compartments by the plurality of air walls; The number of the compartments is four, and the four compartments are sequentially 1st compartment, 2nd compartment, 3rd compartment and 4th compartment in a clockwise direction from the top view; Each of the air walls is composed of two porous rectangular plates, and there is a distance between the two porous rectangular plates; both of the porous rectangular plates in each air wall are installed inside the fermentation chamber; the aperture of the holes on the porous rectangular plate is 2-3 mm; One of the porous rectangular plates on two adjacent air walls is mutually attached and fixedly connected; an air pump is installed on the top of the air wall, and the air pump is a rechargeable air pump; The air inlet of the air pump is located above the air pump; the air outlet pipe of the air pump extends downward from the central position where the plurality of air walls are in contact, and passes through the porous circular plate and extends into the leachate storage chamber; A microwave heating unit is installed in the leachate storage chamber, and the microwave heating unit is a microwave water heater.

[0007] As a preferred solution, an air inlet pipe is provided at the bottom of the fermentation chamber, and a control valve is installed on the air inlet pipe; The air inlet pipe is respectively communicated with an external air compressor and a vacuum pump through a conduit; the air inlet pipe extends upward to the bottom of the porous circular plate; a liquid outlet pipe is installed at the bottom of the fermentation chamber; An air outlet valve is provided on the top of the lid; a carbon dioxide detector is installed on the top of the lid, and the carbon dioxide detector is used to detect the concentration of carbon dioxide in the air outlet valve; A pressure gauge is installed on the side wall of the fermentation chamber, and the pressure gauge is used to detect the pressure inside the fermentation chamber; A temperature controller is installed on the outer wall of the fermentation chamber; a heating belt is installed on the outer circumferential surface of the fermentation chamber; the outer circumferential surface of the fermentation chamber is covered with a heat-insulating cotton, and the heating belt is located between the heat-insulating cotton and the fermentation chamber; the thickness of the heat-insulating cotton is 20-40 mm.

[0008] The temperature controller is used to control the turning on and off of the heating belt; a temperature probe is arranged inside the fermentation bin.

[0009] As a preferred solution, a sector plate slides in each compartment; The sector plate fits on the surface of the porous rectangular plate; a first through hole uniformly arranged is formed in the sector plate, and the aperture of the first through hole is larger than the aperture of the holes on the porous circular plate; the aperture of the first through hole is 1-2 cm; A riser pipe is installed in part of the first through holes, and the top of the riser pipe is closed; air holes uniformly arranged are formed in the riser pipe; The first through hole is a threaded hole; a thread is arranged on one side of the riser pipe located in the through hole, and the riser pipe is in threaded engagement with the through hole.

[0010] As a preferred solution, an n-shaped plate is arranged on the sector plate; The other sides of the n-shaped plates are inserted into two porous rectangular plates of the adjacent air wall; a push plate is arranged between the two porous rectangular plates of the air wall; one side of the n-shaped plate extending into the space between the two porous rectangular plates is fixedly connected to the push plate; The push plate is also provided with second through holes uniformly arranged; one-way valves are installed in the second through holes; the aperture of the second through hole is 1-2 cm.

[0011] As a preferred solution, a pull rod is fixedly connected to the upper surface of each sector plate; a hook is fixedly connected to the pull rod.

[0012] A using method of a pilot-scale device for high-humidity and high-viscosity organic solid waste variable-pressure container fermentation and microbial nitrogen preservation, which is applicable to the above-mentioned pilot-scale device for high-humidity and high-viscosity organic solid waste variable-pressure container fermentation and microbial nitrogen preservation, includes the following steps: Step 1: Place pure water with a volume of 50% in the leachate storage chamber, mix the organic solid waste with auxiliary materials, acid protease and compost bacterial agent, and then add them into each compartment in the fermentation bin, leaving a gas phase space of 15%-30% above the compartment; raise the temperature of the heating belt to a set value one through the temperature controller; Step 2: Start the air compressor to pressurize the fermentation bin to a set value one through the air inlet pipe, then turn off the air compressor, the air in the compartment circulates through the air wall, and at the same time start the air pump to inhale the gas in the gas phase space above the compartment and pump it into the leachate storage chamber through the air outlet pipe to promote gas mixing, aerobic decomposition of organic solid waste and microbial nitrogen preservation reaction (including nitrosation, nitrification reaction, anabolism reaction); Step 3: The microorganisms perform aerobic decomposition on the organic solid waste, generating heat, water vapor, ammonia, and CO2. In particular, acidic protease can accelerate the decomposition of protein components in the organic solid waste to produce ammonia, causing the ammonia to be released during the early stage of fermentation (when the temperature inside the bin is still relatively low), dissolve in the pure water in the leachate storage chamber. The leachate generated during the material fermentation will also flow into the pure water in the leachate storage chamber and mix with the pure water to form a mixed solution. When the CO2 concentration in the gas phase space inside the fermentation bin exceeds 15%, open the gas outlet valve, quickly evacuate the gas inside the fermentation bin, and then close the gas outlet valve. Start the air compressor again to pressurize the fermentation bin to the set value 2. Step 4: Repeat Step 3 until the CO2 concentration in the fermentation bin does not exceed 5% for 12 consecutive hours. Then start the microwave heating unit equipped in the leachate storage chamber to quickly raise the temperature of the mixed solution in the leachate storage chamber to 60 - 70°C, keep it for 30 - 90 min, and then turn off the microwave heating unit to release the ammonia absorbed by water. The ammonia is then utilized again by the microorganisms in the materials inside the bin through nitrification, nitration reactions, and anabolic reactions to maximize the microbial nitrogen preservation. The whole process lasts for 24 - 48 h. Step 5: Turn on the vacuum pump and use the inlet pipe to evacuate the fermentation bin to reduce the pressure in the fermentation bin to the set value 3 and maintain it for 2 - 4 h. Then turn off the vacuum pump. Evacuating the air is mainly used to reduce the moisture content of the materials. Subsequently, end this batch of experiments and empty the materials inside the fermentation bin and the liquid in the leachate storage chamber. Step 6: Repeat Steps 1 to 5 to process the next batch of organic solid waste.

[0013] As a preferred solution, the auxiliary material added to the fermentation bin body in Step 1 is wood chips, and the moisture content of the materials is adjusted to 60 - 65%.

[0014] As a preferred solution, the set value 2 in Step 2 is that the air compressor raises the internal pressure of the fermentation bin body to a pressure gauge reading of 0.3 - 0.5 MPa.

[0015] As a preferred solution, the set value 1 in Step 1 is 45°C.

[0016] As a preferred solution, the set value 3 in Step 5 is a pressure gauge reading of -0.06 ~ -0.04 MPa.

[0017] The beneficial effects of the present invention are as follows: 1. Improve the gas mass transfer efficiency and optimize the aerobic decomposition process of organic solid waste; in the present invention, an air wall is arranged in a variable-pressure container for high-humidity and high-viscosity organic solid waste to divide the fermentation chamber into multiple compartments, and a gas pump is used for local aeration, so that the gas in the chamber is fully mixed. This method effectively improves the gas mass transfer problem in the traditional fermentation process, promotes the uniform distribution of oxygen, thereby improving the aerobic decomposition efficiency of organic solid waste, shortening the fermentation cycle, and improving the overall fermentation efficiency.

[0018] 2. Effectively reduce nitrogen element loss and achieve microbial nitrogen preservation; in the present invention, an ammonia leachate storage chamber absorbs ammonia gas, and a microwave heating unit releases the absorbed ammonia gas, so that the ammonia gas can be reused by microorganisms in the later stage of fermentation. This process not only minimizes nitrogen loss, but also improves the preservation rate of microbial nitrogen by promoting the nitrosation, nitrification reaction and anabolic reaction of ammonia gas, enhances the recycling of nitrogen elements in the fermentation process, and improves the compost quality and nutritional value.

[0019] 3. Compared with atmospheric pressure fermentation, it has higher treatment efficiency and more stable fermentation conditions; in the present invention, the pressurized reaction conditions are maintained in the variable-pressure container for a long time, avoiding the problems of limited oxygen diffusion and local hypoxia commonly found in the atmospheric pressure fermentation process. Compared with atmospheric pressure fermentation, variable-pressure fermentation can significantly improve the gas mass transfer efficiency and promote the uniform decomposition of organic solid waste. At the same time, the pressurized environment can accelerate the metabolic reaction of microorganisms, increase the reaction rate, shorten the fermentation cycle, improve the treatment efficiency and product quality, and is more stable in the recycling of nitrogen elements, thus effectively solving the problems of water loss and nitrogen emission commonly found in atmospheric pressure fermentation technology. Brief Description of the Drawings

[0020] The present invention will be further described below with reference to the accompanying drawings.

[0021] Figure 1 is the overall view of the pilot-scale device for the fermentation of high-humidity and high-viscosity organic solid waste in a variable-pressure container and the preservation of microbial nitrogen of the present invention; Figure 2 is the internal structure diagram of the pilot-scale device for the fermentation of high-humidity and high-viscosity organic solid waste in a variable-pressure container and the preservation of microbial nitrogen of the present invention; Figure 3 is the separation structure diagram of the pilot-scale device for the fermentation of high-humidity and high-viscosity organic solid waste in a variable-pressure container and the preservation of microbial nitrogen of the present invention; Figure 4 is the cooperation structure diagram of the sector plate, riser pipe and push plate of the present invention; Figure 5 is the top view of the present invention; Figure 6 is the present invention Figure 5 The sectional view at A-A in; Figure 7 is the present inventionFigure 6 Partial enlarged view at position B in the figure; Figure 8 This is the present invention Figure 6 Partial enlarged view at position C in the figure; Figure 9 Schematic diagram of VS changes of the atmospheric pressure group and the variable pressure group during the test of the comparative example of the present invention; Figure 10 Schematic diagram of temperature changes of the atmospheric pressure group and the variable pressure group during the test of the comparative example of the present invention.

[0022] In the figure: 1, fermentation tank; 11, leachate storage chamber; 12, perforated circular plate; 13, cell; 14, perforated rectangular plate; 15, air pump; 151, air outlet pipe; 16, air inlet pipe; 17, pressure gauge; 18, temperature controller; 19, liquid outlet pipe; 2, tank cover; 21, air outlet valve; 3, sector plate; 31, first through hole; 32, riser pipe; 33, air hole; 34, n-shaped plate; 35, push plate; 36, second through hole; 37, pull rod. Specific embodiments

[0023] In order to make the technical means, creative features, achieved purposes and functions of the present invention easy to understand, the present invention will be further described below in conjunction with specific embodiments.

[0024] As an embodiment of the present invention; as Figures 1 to 10 shown, on the one hand, the present invention discloses a pilot-scale device for variable-pressure container fermentation and microbial nitrogen preservation of high-humidity and high-viscosity organic solid waste, including a fermentation tank 1; A tank cover 2 is installed on the top of the fermentation tank 1; a leachate storage chamber 11 is arranged at the bottom of the fermentation tank 1; the leachate storage chamber 11 is communicated with the fermentation tank 1; A perforated circular plate 12 is fixedly installed between the leachate storage chamber 11 and the fermentation tank 1, and the aperture of the holes on the perforated circular plate 12 is 2-3 mm; a plurality of air walls are arranged above the perforated circular plate 12; the inner cavity of the fermentation tank 1 is divided into a plurality of cells 13 by a plurality of air walls; The number of the cells 13 is four, and the four cells 13 are sequentially 1 cell, 2 cell, 3 cell and 4 cell in a clockwise direction from the top view direction; Each of the air walls is composed of two perforated rectangular plates 14, and there is a distance between the two perforated rectangular plates 14; both of the perforated rectangular plates 14 in each air wall are installed inside the fermentation tank 1; the aperture of the holes on the perforated rectangular plate 14 is 2-3 mm; One of the perforated rectangular plates 14 on two adjacent air walls is mutually attached and fixedly connected; an air pump 15 is installed on the top of the air wall, and the air pump 15 is a rechargeable air pump 15; The air inlet of the air pump 15 is located above the air pump 15; the outlet pipe 151 of the air pump 15 extends downward from the central position where multiple air walls contact, passes through the porous circular plate 12 and extends into the leachate storage chamber; A microwave heating unit is installed in the leachate storage chamber, and the microwave heating unit is a microwave water heater; In this embodiment, an inlet pipe 16 is provided at the bottom of the fermentation tank 1, and a control valve is installed on the inlet pipe; The inlet pipe 16 is communicated with an external air compressor and a vacuum pump respectively through a conduit; the inlet pipe 16 extends upward to the bottom of the porous circular plate 12; an outlet pipe 19 is installed at the bottom of the fermentation tank 1; An air outlet valve 21 is provided at the top of the tank cover 2; a carbon dioxide detector is installed at the top of the tank cover 2, and the carbon dioxide detector is used to detect the concentration of carbon dioxide in the air outlet valve 21; A pressure gauge 17 is installed on the side wall of the fermentation tank 1, and the pressure gauge 17 is used to detect the pressure inside the fermentation tank 1; A temperature controller 18 is installed on the outer wall of the fermentation tank 1; a heating belt is installed on the outer circumferential surface of the fermentation tank 1; the outer circumferential surface of the fermentation tank 1 is covered with a heat insulation cotton, and the heating belt is located between the heat insulation cotton and the fermentation tank 1; the thickness of the heat insulation cotton is 20-40 mm.

[0025] The temperature controller 18 is used to control the opening and closing of the heating belt; a temperature probe is provided inside the fermentation tank 1; During implementation, when treating organic solid waste, first place pure water with a volume of 50% in the leachate storage chamber 11. At this time, the outlet pipe 151 on the air pump 15 is located below the liquid level of the pure water, and one side of the inlet pipe 16 extending into the leachate storage chamber 11 is located above the liquid level; then the material obtained by mixing the organic solid waste with auxiliary materials, acid protease and compost bacteria agent is added to each compartment 13 in the fermentation tank 1, and the stacking height of the material cannot exceed the height of the air wall, and the tank cover 2 is closed, and a gas phase space of 15%-30% is reserved above the compartment 13. Then, the heating belt is controlled by the temperature controller 18 to heat, and the temperature of the heating belt is gradually increased to 45°C. Then, the external air compressor is used to gradually pressurize the fermentation tank 1 through the inlet pipe 16, and the pressure inside the fermentation tank 1 is gradually pressurized to 0.3-0.5 MPa, and the reaction conditions after pressurization are maintained in the fermentation tank 1 for a long time. When the gas enters the inside of the fermentation tank 1, the gas will flow between the two porous rectangular plates 14 in the air wall and pass through the holes on the porous rectangular plate 14 to contact the materials in each compartment 13, so as to provide oxygen for the microorganisms in the materials and enable the materials to ferment normally. When the materials ferment, leachate will be generated, and the leachate will flow through the holes on the porous circular plate 12 into the leachate storage chamber 11 and be mixed with the pure water in the leachate storage chamber 11 to form a mixed liquid; During the implementation process, when the material is fermenting, the air pump 15 is started to work. During the operation of the air pump 15, the gas above the cell 13 and in the reserved gas phase space can be extracted. The extracted gas will be led to the lower part of the liquid level of the mixed liquid through the outlet pipe 151 on the air pump 15. When the gas flows out of the mixed liquid, the gas will flow upward through the holes on the porous circular plate 12. Part of the gas will flow into the air wall through the empty spaces on the porous circular plate 12 and then flow in the air wall. During the process of the gas flowing in the air wall, the gas will pass through the holes on the porous rectangular plate 14 and flow into the material interior, thereby providing oxygen for the microorganisms in the material. At the same time, part of the gas will directly flow from the holes on the porous circular plate 12 to the inside of the cell 13 from the bottom of the cell 13, and then gradually pass through the material in the cell 13 to provide oxygen for the microorganisms in the material. When the gas rises to the gas phase space, it will be extracted by the air pump 15 again, led to the lower part of the mixed liquid, and the gas will flow upward again, and this cycle continues; During the implementation process, during the process of the gas circulating and flowing, the air in the fermentation tank 1, the water vapor and ammonia gas generated by the material fermentation can be fully mixed. On the one hand, it promotes the aerobic decomposition of the organic solid waste, the dissolution of ammonia gas in the water formed on the surface of the fermentation material, and the nitrosation, nitrification reaction and anabolic reaction of ammonia gas (including ammonium ions). On the other hand, it promotes the absorption of the unreacted ammonia gas by the mixed liquid in the leachate storage chamber 11; During the implementation process, when the CO2 concentration in the gas phase space in the fermentation tank 1 to be fermented exceeds 15%, the air outlet valve 21 is opened, the gas in the fermentation tank 1 is quickly emptied and then the air outlet valve 21 is closed. Then the air compressor is started again to pressurize the fermentation tank 1 to 0.3 - 0.5 MPa. Subsequently, the CO2 concentration in the gas phase space is continuously monitored. If the CO2 concentration still exceeds 15%, the air outlet valve 21 is continuously opened, the gas in the fermentation tank 1 is quickly emptied, and the air outlet valve 21 is closed. When the CO2 concentration in the fermentation tank 1 does not exceed 5% for 12 consecutive hours, the microwave heating unit equipped in the leachate storage chamber 11 is started. After the microwave heating unit is started, the temperature of the mixed liquid in the leachate storage chamber 11 can be quickly increased to 60 - 70 °C, and after maintaining for 30 - 90 min, the microwave heating unit is closed, so that the ammonia gas absorbed by the water is released and is utilized again by the microorganisms in the material in the tank body through nitrosation, nitrification reaction and anabolic reaction, and the microbial nitrogen preservation is maximally realized. The whole process lasts for 24 - 48 h; Finally, the vacuum pump is turned on to evacuate the fermentation tank 1 through the inlet pipe 16, so that the pressure in the fermentation tank 1 is reduced to -0.06~-0.04 MPa and maintained for 2 - 4 h, and then the vacuum pump is closed. The material in the fermentation tank 1 and the liquid in the leachate storage chamber 11 are emptied by using the outlet pipe 19.

[0026] As another embodiment of the present invention; a sector plate 3 is slidably disposed in each of the compartments 13; the sector plate 3 is in surface contact with the porous rectangular plate 14; a first through hole 31 is uniformly arranged on the sector plate 3, and the aperture of the first through hole 31 is larger than the aperture of the holes on the porous circular plate 12; the aperture of the first through hole 31 is 1-2 cm; A riser 32 is installed in a part of the first through holes 31, and the top of the riser 32 is closed; air holes 33 are uniformly arranged on the riser 32; The first through hole 31 is a threaded hole; a thread is provided on one side of the riser 32 located in the through hole, and the riser 32 is in threaded engagement with the through hole; In this embodiment, an n-shaped plate 34 is provided on the sector plate 3; the other sides of the n-shaped plates 34 are inserted into two porous rectangular plates 14 of the adjacent air walls; a push plate 35 is provided between the two porous rectangular plates 14 of the air wall; one side of the n-shaped plate 34 extending into the space between the two porous rectangular plates 14 is fixedly connected to the push plate 35; The push plate 35 is also provided with uniformly arranged second through holes 36; a one-way valve is installed in the second through holes 36; the aperture of the second through hole 36 is 1-2 cm; In this embodiment, a pull rod 37 is fixedly connected to the upper surface of each sector plate 3; a hook is fixedly connected to the pull rod 37; During implementation, since a sector plate 3 is provided in each compartment 13, when the material is placed inside the compartment 13, first, the sector plate 3 is placed in the compartment 13, and the compartment 13 is finally brought into contact with the porous circular plate 12. Subsequently, the material is placed on the sector plate 3 inside the compartment 13. Since a riser 32 is installed in a part of the first through holes 31 on the sector plate 3, when the gas is pumped to flow upward below the liquid level of the mixed liquid, part of the gas will pass through the holes on the porous circular plate 12 and enter the first through holes 31. Part of the gas in the first through holes 31 will directly enter the riser 32. The gas entering the riser 32 will be discharged through the uniformly arranged air holes 33 on the air pipe. The gas discharged through the air holes 33 will act on the material located inside the compartment 13, so that the gas contacts the material located in the middle of the compartment 13 and provides oxygen for the microorganisms. During this process, since the riser 32 is directly erected in the middle of the material, gas can be introduced into the material in the middle of the compartment 13, thereby avoiding the phenomenon that when only the two porous rectangular plates 14 on the air wall are used to introduce gas to the material, the gas cannot directly enter the interior of the material, resulting in the obstruction of oxygen diffusion and local hypoxia, which in turn inhibits the decomposition ability of microorganisms, prolongs the fermentation cycle, and reduces the fermentation efficiency; In the implementation process, since the riser 32 is installed in the first through hole 31 by threading, during the fermentation of the material, different numbers of risers 32 can be selected to be installed on the first through hole 31, and at the same time, the installation distance and density of the risers 32 can be controlled to supplement oxygen inside the material; In the implementation process, since a push plate 35 is fixedly connected to each sector plate 3 through an n-shaped plate 34, after the sector plate 3 is placed inside the cell 13, the n-shaped plate 34 also places the push plate 35 between two porous rectangular plates 14 in the air wall. Since a second through hole 36 is formed in the push plate 35, the gas flowing out of the mixed liquid can also flow into the air wall through the second through hole 36 for diffusion. After the fermentation is completed, the lifting mechanism can be used to hook the pull ring and lift it upward. When lifting, the pull rod 37 will pull the sector plate 3 upward. The upward-moving sector plate 3 will drive the material on the sector plate 3 upward, and then the material can be taken out, so that the material can be taken out more conveniently. At the same time, when the sector plate 3 moves upward, the push plate 35 can be driven by the n-shaped plate 34 to move upward in the air wall, so that the material falling into the air wall can be pushed out, avoiding too much material accumulating in the air wall and being difficult to clean, and at the same time avoiding the material blocking in the air wall and blocking the diffusion of the gas.

[0027] On the other hand, the present invention also provides a method for using a pilot-scale device for fermenting high-moisture and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen, which is applicable to the above-mentioned pilot-scale device for fermenting high-moisture and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen, and includes the following steps: Step 1: Place pure water with a volume of 50% in the leachate storage chamber 11. Mix the organic solid waste with auxiliary materials, acid protease, and compost inoculant and then add them to each cell 13 in the fermentation chamber 1, leaving a gas phase space of 15%-30% above the cell 13; raise the temperature of the heating belt to a set value 1 through the temperature controller 18; Step 2: Start the air compressor to pressurize the fermentation chamber 1 to a set value 2 through the air inlet pipe 16, turn off the air compressor, the air in the cell 13 circulates through the air wall, and at the same time start the air pump 15 to inhale the gas in the gas phase space above the cell 13 and pump it into the leachate storage chamber 11 through the air outlet pipe 151 to promote gas mixing, aerobic decomposition of organic solid waste, and microbial nitrogen preservation reactions (including nitrite oxidation, nitrification reactions, and anabolic reactions); Step 3: Microorganisms perform aerobic decomposition on the organic solid waste, generating heat, water vapor, ammonia, and CO2. In particular, acidic protease can accelerate the decomposition of protein components in the organic solid waste to produce ammonia, causing the ammonia to be released during the early stage of fermentation (when the temperature in the fermentation chamber is still relatively low), dissolve in the pure water in the leachate storage chamber 11. The leachate generated during the material fermentation also flows into the pure water in the leachate storage chamber 11 and mixes with the pure water to form a mixed solution. When the CO2 concentration in the gas phase space in the fermentation chamber 1 exceeds 15%, open the air outlet valve 21, quickly evacuate the gas in the fermentation chamber 1, and then close the air outlet valve 21. Start the air compressor again to pressurize the fermentation chamber 1 to the set value one; Step 4: Repeat Step 3 until the CO2 concentration in the fermentation chamber 1 does not exceed 5% for 12 consecutive hours. Then start the microwave heating unit equipped in the leachate storage chamber 11 to quickly raise the temperature of the mixed solution in the leachate storage chamber 11 to 60 - 70°C, maintain it for 30 - 90 minutes, and then turn off the microwave heating unit to release the ammonia absorbed by water. The ammonia is then utilized again by the microorganisms in the materials in the chamber through nitrification, nitration reactions, and anabolic reactions to maximize microbial nitrogen preservation. The whole process lasts for 24 - 48 hours; Step 5: Turn on the vacuum pump and use the intake pipe 16 to evacuate the fermentation chamber 1 to reduce the pressure in the fermentation chamber 1 to the set value three and maintain it for 2 - 4 hours. Evacuating the air is mainly used to reduce the moisture content of the materials. Then end this batch of experiments and empty the materials in the fermentation chamber 1 and the liquid in the leachate storage chamber 11; Step 6: Repeat Steps 1 to 5 to process the next batch of organic solid waste.

[0028] Specifically; the auxiliary material added to the fermentation chamber 1 in Step 1 is wood chips, and the moisture content of the materials is adjusted to 60 - 65%.

[0029] More specifically, in Step 2, the set value two is that the air compressor raises the internal pressure of the fermentation chamber 1 until the reading of the pressure gauge 17 is 0.3 - 0.5 MPa.

[0030] More specifically, the set value one in Step 1 is 45°C.

[0031] More specifically, the set value three in Step 5 is that the reading of the pressure gauge 17 is -0.06~-0.04 MPa.

[0032] As a comparative example of the present invention; To verify the fermentation rate of the variable-pressure container fermentation and microbial nitrogen preservation pilot device and its usage method for high-humidity and high-viscosity organic solid waste, an atmospheric pressure group and a variable-pressure group are set up. Both groups are fermented using the variable-pressure container fermentation and microbial nitrogen preservation pilot device for high-humidity and high-viscosity organic solid waste, and further comparison and explanation are carried out; For the variable-pressure group, the organic solid residues for aerobic fermentation, fermentation inoculum, and wood chips are put into the compartment 13, and air is supplied to the compartment 13 through an air compressor to increase the pressure in the compartment 13 to 0.3 MPa. At the same time, a temperature controller 18 is set to set the temperature to 45 °C, so that the microorganisms inside the compartment 13 become active, quickly decompose the easily utilizable organic matter, and generate a large amount of heat, thereby increasing the temperature inside the compartment 13. During the experiment, the ventilation is changed every 12 hours, and samples are collected every day for 5 days. When the CO2 concentration in the compartment 13 does not exceed 5% for 12 consecutive hours, the microwave heating unit equipped in the leachate storage chamber 11 is started to quickly raise the temperature of the liquid in the leachate storage chamber 11 to 60 °C. After maintaining for 60 min, the microwave heating unit is turned off to release the ammonia absorbed by water, which is then utilized again by the microorganisms in the materials in the bin through nitrosation, nitrification reactions, and anabolic reactions, maximizing the microbial nitrogen preservation. The whole process lasts for 24 h. The vacuum pump is turned on to evacuate the fermentation bin 1, reducing the pressure in the fermentation bin 1 to -50 kPa and maintaining it for 2 h, then the vacuum pump is turned off to end this batch of tests, and the materials in the fermentation bin 1 and the liquid in the leachate storage chamber 11 are emptied.

[0033] For the atmospheric-pressure group, the temperature controller 18 is set to set the temperature to 45 °C, the ventilation rate is 0.5 L / kg·min, and the intermittent ventilation (10 min on / 10 min off) method is adopted for 5 days.

[0034] In the comparative example of the present invention, the temperature of the variable-pressure group is significantly higher than that of the atmospheric-pressure group, and the percentage content of VS% volatile solids in the total solids is significantly lower than that of the atmospheric-pressure group. From Figure 9 and Figure 10 it can be seen that under the conditions of the variable-pressure container fermentation and microbial nitrogen preservation pilot device using the same high-humidity and high-viscosity organic solid waste, the variable-pressure group can effectively promote the microbial activity and the fermentation rate of organic solid waste, and shorten the fermentation cycle.

[0035] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art of this industry should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. A pilot-scale device for fermentation of highly humid and highly viscous organic solid waste in a variable-pressure container and microbial nitrogen preservation, characterized in that, Comprising a fermentation tank (1); A tank cover (2) is installed at the top of the fermentation tank (1); a leachate storage chamber (11) is arranged at the bottom of the fermentation tank (1); the leachate storage chamber (11) is communicated with the fermentation tank (1); A porous circular plate (12) is fixedly installed between the leachate storage chamber (11) and the fermentation tank (1); a plurality of air walls are arranged above the porous circular plate (12); the inner cavity of the fermentation tank (1) is divided into a plurality of compartments (13) by the plurality of air walls; Each air wall is composed of two porous rectangular plates (14), and a distance is left between the two porous rectangular plates (14); both of the two porous rectangular plates (14) within each air wall are installed inside the fermentation tank (1); One of the porous rectangular plates (14) on two adjacent air walls is mutually attached and fixedly connected; an air pump (15) is installed at the top of the air wall; The air inlet of the air pump (15) is located above the air pump (15); the air outlet pipe (151) of the air pump (15) extends downward from the central position where the plurality of air walls are in contact, and passes through the porous circular plate (12) and extends into the leachate storage chamber; A microwave heating unit is installed in the leachate storage chamber.

2. The pilot-scale device for fermentation of high-humidity and high-viscosity organic solid waste in a variable-pressure container and microbial nitrogen preservation according to claim 1, characterized in that: An air inlet pipe (16) is provided at the bottom of the fermentation tank (1), and a control valve is installed on the air inlet pipe; The air inlet pipe (16) is communicated with an external air compressor and a vacuum pump respectively through a conduit; the air inlet pipe (16) extends upward to the bottom of the porous circular plate (12); a liquid outlet pipe (19) is installed at the bottom of the fermentation tank (1); An air outlet valve (21) is arranged at the top of the tank cover (2); a carbon dioxide detector is installed at the top of the tank cover (2), and the carbon dioxide detector is used for detecting the concentration of carbon dioxide in the air outlet valve (21); A pressure gauge (17) is installed on the side wall of the fermentation tank (1), and the pressure gauge (17) is used for detecting the pressure inside the fermentation tank (1); A temperature controller (18) is installed on the outer wall of the fermentation tank (1); a heating belt is installed on the outer circumferential surface of the fermentation tank (1); the outer circumferential surface of the fermentation tank (1) is covered with heat preservation cotton, and the heating belt is located between the heat preservation cotton and the fermentation tank (1); The temperature controller (18) is used for controlling the opening and closing of the heating belt; a temperature probe is arranged inside the fermentation tank (1).

3. The pilot-scale device for fermentation of high-humidity and high-viscosity organic solid waste in a variable-pressure vessel and microbial nitrogen preservation according to claim 2, wherein: A sector plate (3) slides in each compartment (13); The sector plate (3) is attached to the surface of the porous rectangular plate (14); a plurality of first through holes (31) are uniformly arranged on the sector plate (3), and the aperture of the first through holes (31) is larger than the aperture of the holes on the porous circular plate (12); Vertical pipes (32) are installed in some of the first through holes (31), and the tops of the vertical pipes (32) are closed; a plurality of air holes (33) are uniformly arranged on the vertical pipes (32); The first through holes (31) are threaded holes; threads are provided on one side of the vertical pipe (32) located in the through hole, and the vertical pipe (32) is in threaded engagement with the through hole.

4. The pilot-scale device for fermenting high-humidity and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen according to claim 3, characterized in that: An n-shaped plate (34) is arranged on the sector plate (3); On the other side of the n-type plate (34), it is inserted into two porous rectangular plates (14) of adjacent air walls; a push plate (35) is arranged between the two porous rectangular plates (14) of the air wall; one side of the n-type plate (34) extending between the two porous rectangular plates (14) is fixedly connected to the push plate (35); The push plate (35) is also provided with uniformly arranged second through holes (36).

5. The pilot device for fermentation and microbial nitrogen preservation of high-humidity and high-viscosity organic solid waste in a variable-pressure container according to claim 4, characterized in that: On the upper surface of each sector plate (3), a pull rod (37) is fixedly connected; hooks are fixedly connected to the pull rods (37).

6. A method for using a pilot-scale device for fermenting high-moisture and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen, characterized in that: This method is applicable to the pilot device for fermentation and microbial nitrogen preservation of high-humidity and high-viscosity organic solid waste in a variable-pressure container according to any one of claims 1-5, and includes the following steps: Step 1: Place pure water with a volume of 50% in the leachate storage chamber (11), mix the organic solid waste with auxiliary materials, acid protease, and compost bacteria agent, and then add them to each compartment (13) in the fermentation chamber (1). There is a gas phase space of 15%-30% left above the compartment (13); raise the temperature of the heating belt to the set value one through the temperature controller (18); Step 2: Start the air compressor and pressurize the fermentation chamber (1) to the set value two through the air inlet pipe (16), then turn off the air compressor. The air in the compartment (13) circulates through the air wall. At the same time, start the air pump (15) to inhale the gas in the gas phase space above the compartment (13) and pump it into the leachate storage chamber (11) through the air outlet pipe (151) to promote gas mixing, aerobic decomposition of organic solid waste, and microbial nitrogen preservation reaction; Step 3: Microorganisms perform aerobic decomposition on the organic solid waste, generating heat, water vapor, ammonia, and CO2. In particular, acid protease can accelerate the decomposition of protein components in the organic solid waste to produce ammonia, causing ammonia to be released concentrated in the early stage of fermentation and dissolved in the pure water in the leachate storage chamber (11). The leachate generated during material fermentation will also flow into the pure water in the leachate storage chamber (11) and mix with the pure water to form a mixed solution; when the CO2 concentration in the gas phase space in the fermentation chamber (1) exceeds 15%, open the air outlet valve (21), quickly evacuate the gas in the fermentation chamber (1), and then close the air outlet valve (21). Start the air compressor again to pressurize the fermentation chamber (1) to the set value one; Step 4: Repeat Step 3 until the CO2 concentration in the fermentation chamber (1) does not exceed 5% continuously for 12 hours. Then start the microwave heating unit equipped in the leachate storage chamber (11) to quickly raise the temperature of the mixed solution in the leachate storage chamber (11) to 60-70 °C. Keep it for 30-90 minutes and then turn off the microwave heating unit to release the ammonia absorbed by water, which is then utilized by microorganisms in the materials in the chamber body through nitrite, nitrification reaction, and anabolic reaction again, achieving microbial nitrogen preservation to the greatest extent. The whole process lasts for 24-48h; Step 5: Turn on the vacuum pump and use the intake pipe (16) to evacuate the fermentation tank (1) to reduce the pressure in the fermentation tank (1) to Set Value 3 and maintain it for 2 - 4 h. Then, turn off the vacuum pump. Evacuating the air is mainly used to reduce the moisture content of the material. Subsequently, end this batch of tests and empty the material in the fermentation tank (1) and the liquid in the leachate storage chamber (11). Step 6: Repeat Steps 1 to 5 to process the next batch of organic solid waste.

7. The method for using the pilot-scale device for fermenting high-humidity and high-viscosity organic solid waste in a variable-pressure vessel and preserving microbial nitrogen according to claim 6, characterized in that: In Step 1, the auxiliary material added to the fermentation tank (1) is wood chips, and the moisture content of the material is adjusted to 60 - 65%.

8. The method for using the pilot-scale device for fermenting high-humidity and high-viscosity organic solid waste in a variable-pressure vessel and preserving microbial nitrogen according to claim 6, characterized in that: In Step 2, Set Value 2 is that the air compressor raises the internal pressure of the fermentation tank (1) until the reading of the pressure gauge (17) is 0.3 - 0.5 MPa.

9. The method for using the pilot-scale device for fermenting high-moisture and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen according to claim 6, characterized in that: In Step 1, Set Value 1 is 45 °C.

10. The method for using the pilot-scale device for fermenting high-humidity and high-viscosity organic solid waste in a variable-pressure container and preserving microbial nitrogen according to claim 6, characterized in that: In Step 5, Set Value 3 is that the reading of the pressure gauge (17) is -0.06 to -0.04 MPa.

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