A biogas slurry-based fermentation broth production device and production method

Abstract

The present application relates to a kind of biogas slurry-based fermentation broth production device and production method, solve the existing biogas slurry component complex, it is difficult to use, smell is unpleasant, acceptance is not high, and the problem of high cost of biogas slurry processing.This device greenhouse is set up above fermentation tank, and the middle part of fermentation tank is provided with shunt wall along the length direction, and the both ends of shunt wall are left empty between the end wall of fermentation tank, and one end of fermentation tank is provided with recessed secondary pool, and the both sides and both ends of fermentation tank form the circulation channel of biogas slurry on the both sides of shunt wall, and water removal car is arranged on the circulation channel, and the liquid inlet pipe is arranged on the secondary pool of fermentation tank, and the liquid outlet pipe is arranged in secondary pool, and the dosing pipe of adding composite microbial inoculant is further arranged above secondary pool.The present application forms efficient composite microorganism-amino acid fermentation broth product after fermentation treatment to biogas slurry, which can partially replace chemical fertilizer, greatly reduces the processing cost of biogas slurry, reduces the economic burden of breeder, and reduces the problem of biogas slurry environmental pollution.

Description

Technical Field

[0001] This invention belongs to the field of agricultural fermentation, and relates to a biogas slurry pond, and particularly to a fermentation liquid production device and production method based on biogas slurry. Background Technology

[0002] The residue from livestock and poultry manure, after being fermented by microorganisms to produce biogas and used as fertilizer, undergoes solid-liquid separation, with the liquid portion becoming biogas slurry. Returning biogas slurry to the fields connects livestock farming with crop cultivation, offering multiple functions such as soil improvement and enhanced agricultural product quality. Analysis shows that after anaerobic fermentation, pig farm excrement retains 90% of its nutrients, with particularly high levels of nitrogen, phosphorus, and potassium. It also contains trace elements, amino acids, humic acid, and bioactive substances, which can replace or partially replace chemical fertilizers, improving soil environment, enhancing agricultural product quality, and suppressing pests and diseases. Effective utilization of biogas slurry can achieve energy and resource recovery, reducing harm to the environment and health—a highly beneficial measure. The Ministry of Agriculture and Rural Affairs, the Ministry of Ecology and Environment, and other relevant departments have consistently advocated and encouraged the application of biogas slurry return-to-field technology to build a balanced agricultural ecosystem between crop cultivation and livestock farming, using biogas technology as a link. Therefore, the scientific utilization of biogas slurry resources is of great significance for achieving a "dual-carbon" agricultural economy.

[0003] However, in actual use, biogas slurry has a complex composition, with high levels of particulate matter and soluble substances, making its utilization difficult. Therefore, the main method of treating biogas slurry at present is to build wastewater treatment plants in areas with dense livestock farming, treating the biogas slurry as wastewater. On average, treating one ton of biogas slurry costs 10-40 yuan, which is a heavy burden for livestock farms. At the same time, biogas slurry has high ammonia volatility and an unpleasant odor, resulting in low acceptance of biogas slurry products by farmers. Therefore, exploring the scientific utilization of biogas slurry is a major production challenge for livestock enterprises. Summary of the Invention

[0004] The purpose of this invention is to address the problems of existing biogas slurry, such as its complex composition, difficulty in utilization, unpleasant odor, low acceptability, and high treatment costs. This invention provides a biogas slurry-based fermentation liquid production device and method. By adding compound microbial agents to a dedicated biogas slurry tank, the existing biogas slurry undergoes aerobic fermentation. After treatment by this fermentation process, the concentration of suspended solids in the biogas slurry is reduced, ammonia volatilization is decreased, and the odor is significantly reduced. Furthermore, the number of fecal coliforms and roundworm eggs in the fermented liquid meets the requirements for farmland irrigation water quality, and the microbial community composition has also changed significantly, making it suitable for use as liquid fertilizer in the fields. This solution offers low biogas slurry treatment costs, and the biogas slurry can partially replace chemical fertilizers for reuse, not only alleviating the wastewater treatment burden of livestock farms but also reducing agricultural production costs.

[0005] The technical solution adopted by this invention to solve its technical problem is: a fermentation liquid production device based on biogas slurry, including a fermentation tank, a shed built above the fermentation tank, the shed covered with a light-transmitting plastic film, a diversion wall set along the length of the middle of the fermentation tank, with gaps between the two ends of the diversion wall and the end wall of the fermentation tank, a recessed secondary tank set at one end of the fermentation tank, the fermentation tank forming a biogas slurry circulation channel on both sides and at both ends of the diversion wall, a waterwheel set on the circulation channel to drive the flow of biogas slurry, an inlet pipe set above the secondary tank of the fermentation tank, an outlet pipe set in the secondary tank, and a drug delivery pipe for adding compound microbial agents set above the secondary tank.

[0006] To address the issue of high ammonia content in biogas slurry, particularly in greenhouse applications where it can cause gas pollution, this device re-ferments the biogas slurry before use. It incorporates multifunctional probiotics abundant in the soil, such as Bacillus, Lactobacillus, and photosynthetic bacteria. Through fermentation, ammonia emissions are significantly reduced. Microbial absorption and transformation convert some ammonia ions into amino acids, significantly improving fertilizer utilization. Simultaneously, fermentation stabilizes the pH to 7-8, making it suitable for soil use. The device continuously circulates and aerates the biogas slurry within the fermentation tank, mixing it with microorganisms for fermentation. The added microbial agents are live bacterial preparations containing a large number of beneficial microorganisms, obtained from local farmland through separation, purification, and a series of methods. After treatment with the compound microbial agent, the concentration of suspended solids and ammonia volatilization in the biogas slurry are reduced, while the amino acid content is increased. These microbial agents have multiple functions, including promoting plant root growth, disease prevention, deodorization, potassium solubilization, phosphorus solubilization, and nitrogen fixation. Using this technology effectively reduces fertilizer use, achieving multiple goals such as soil improvement, environmental restoration, and improved crop quality. The entire system requires minimal fixed asset investment, is easy to maintain, requires no human intervention, and can be remotely controlled. For example, building a facility capable of processing 100 tons of biogas slurry per day would require a total investment of no more than 600,000 yuan, with low processing costs; the cost of converting each ton of biogas slurry into a high-efficiency amino acid fermentation liquid is less than 3 yuan. The processing speed is fast; traditional biogas slurry can be converted into a high-efficiency compound microbial-amino acid fermentation liquid in about 10 days after treatment with special microorganisms, and the odor is largely eliminated, increasing farmers' acceptance.

[0007] Preferably, the fermentation tank is connected to a transfer tank via an inlet pipe, and the transfer tank is connected to the original biogas slurry tank via a delivery pipe. An ozone generator for ozone sterilization is connected to the side of the delivery pipe. Before entering the fermentation tank, the biogas slurry undergoes ozone treatment to kill fecal coliforms and roundworm eggs in the original biogas slurry. Then, aeration in the transfer tank promotes the natural decomposition of ozone, avoiding any impact on the microorganisms in the fermentation tank.

[0008] Preferably, the diversion wall is equipped with a millimeter-wave radar for monitoring the foam height in the fermentation tank, and the top of the diversion wall is also equipped with several spray nozzles for defoaming. High-concentration biogas slurry easily produces foam during fermentation. The millimeter-wave radar of this application monitors the foam in the fermentation tank. When the foam exceeds a certain height, the spray nozzles are activated to spray the fermentation tank in full coverage to defoam, and at the same time, the sprayed water mist redissolves ammonia gas volatilized in the air into the biogas slurry.

[0009] Preferably, an ammonia recovery device is also provided on the exterior of one side of the fermentation tank. This ammonia recovery device includes a spray tower, with a suction pump connected to one side of the bottom of the spray tower to draw gas from above the fermentation tank inside the greenhouse. An exhaust pipe is located at the top of the spray tower, and a water tank is located below the interior of the spray tower. Multiple spray pipes are installed above the interior of the spray tower, and a circulation pump is installed between the water tank and the spray pipes. The water tank also has a return pipe connected to the fermentation tank. The ammonia recovery device can draw in, spray, dissolve, and recover ammonia gas inside the greenhouse and above the fermentation tank.

[0010] Preferably, the water tank is also equipped with an ammonia concentration sensor.

[0011] Preferably, waterwheels are installed on both sides of the diversion wall in the circulation channel. Each waterwheel pumps water clockwise or counterclockwise, and the waterwheels are movable along the circulation channel. Each waterwheel consists of a rotating shaft and blades on the shaft. The rotation of the water tank drives the flow and circulation of the biogas slurry, ensuring uniform fermentation. The waterwheel also provides a certain degree of aeration. The number of waterwheels can be 2, 4, 6, etc., depending on their power and the size of the fermentation tank.

[0012] Preferably, the bottom surface of the fermentation tank is also equipped with several aeration pumps or aeration pipes.

[0013] A method for producing fermentation broth based on biogas slurry, using the aforementioned production apparatus, includes the following process flow:

[0014] On the first day, fill the secondary tank of the fermentation tank with 1-3 parts compound microbial agent, 6-10 parts clean water and 6-10 parts biogas slurry. Move the water truck to the secondary tank and start it. Control the biogas slurry temperature at 25-35 ℃. After running for 2 days, the biogas slurry turns red and has almost no odor.

[0015] On the third day, add 20-30 parts clean water and 20-30 parts biogas slurry to the fermentation tank, start the aeration pump or aeration pipe in the fermentation tank, and run it for 2 days.

[0016] Starting on the 5th day, add 20-30 portions of biogas slurry every 3 hours; at this time, the mobile water truck is evenly distributed in the circulation channel and started until the fermentation tank is filled with 1000-1200 portions of biogas slurry, then stop adding and removing biogas slurry, and run for 3-5 days;

[0017] During the day, the fermentation tank produces 10-15 portions of biogas slurry every 3 hours as fermentation liquid product, and then replenishes an equal amount of biogas slurry, with the output going out first and the input coming in later.

[0018] As a preferred embodiment, the compound microbial agent, by weight, includes 20 parts of Bacillus subtilis, 20 parts of potassium-solubilizing bacteria, 20 parts of phosphorus-solubilizing bacteria, 10 parts of EM photosynthetic bacteria, 10 parts of lactic acid bacteria, 10 parts of yeast, and 10 parts of nitrifying bacteria.

[0019] As a preferred option, millimeter-wave radar and nozzles are installed on the diversion wall of the fermentation tank. When the height of the biogas slurry foam is less than 1-1.2 meters from the top of the fermentation tank, the nozzles are activated for 10-15 minutes to spray and defoam. The biogas slurry in the fermentation tank is used for spraying.

[0020] As a preferred method, during the process of transferring biogas slurry from the original biogas slurry pond to the transfer pond, 40g of ozone is mixed with every 5 tons of biogas slurry to kill fecal coliforms and roundworm eggs. Before the first injection of liquid into the fermentation pond, the transfer pond is continuously aerated for at least 48 hours. After each subsequent injection of liquid into the fermentation pond, an equal amount of liquid is taken from the transfer pond, and the amount of liquid taken each time does not exceed 1 / 15 of the capacity of the transfer pond.

[0021] Preferably, the ammonia recovery device is started before the fermentation tank accumulates 1000-1200 parts of biogas slurry. The spray liquid of the ammonia recovery device is clean water. When the ammonia concentration in the water tank in the spray tower exceeds 80% of the saturation concentration, the water in the water tank is replaced and the water in the water tank is discharged into the fermentation tank.

[0022] This invention ferments biogas slurry to form a highly efficient compound microbial-amino acid fermentation liquid product that can partially replace chemical fertilizers, achieving biogas slurry return to the field. The fermentation tank has low investment costs, simple equipment maintenance, and can be operated unattended, greatly reducing the treatment cost of biogas slurry, reducing the economic burden on livestock farmers, and reducing the environmental pollution caused by biogas slurry. Attached Figure Description

[0023] The invention will now be further described with reference to the accompanying drawings.

[0024] Figure 1 This is a schematic diagram of the external structure of a fermentation tank according to the present invention.

[0025] Figure 2 This is a schematic diagram of the internal structure of a fermentation tank according to the present invention.

[0026] Figure 3 This is a schematic diagram of the biogas slurry source tank, transfer tank, and fermentation tank of the present invention.

[0027] In the diagram: 1. Fermentation tank, 2. Greenhouse, 3. Door, 4. Inlet pipe, 5. Outlet pipe, 6. Dosing pipe, 7. Control box, 8. Ammonia recovery device, 9. Diversion wall, 10. Waterwheel, 11. Aeration pipe, 12. Secondary tank, 13. Sprinkler, 14. Circulation channel, 15. Transfer tank, 16. Biogas slurry source tank, 17. Delivery pipe, 18. Ozone generator. Detailed Implementation

[0028] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0029] Example: A fermentation broth production device based on biogas slurry, such as... Figure 1-3 As shown. This apparatus includes a fermentation tank 1, as described. Figure 3 As shown, a transfer tank 15 is connected to the front of the fermentation tank 1 via an inlet pipe 4. The front of the transfer tank 15 is connected to the biogas slurry source tank 16 via a delivery pipe 17. An ozone generator 18 for providing ozone sterilization is connected to the side of the delivery pipe 17. The biogas slurry is transported in the following order: biogas slurry source tank 16, delivery pipe 17, fermentation tank 1.

[0030] like Figure 1 , 2 As shown, a greenhouse 2 is erected above the fermentation tank 1. The greenhouse includes a steel frame covered with a translucent plastic film. One end of the greenhouse has a door 3, which is closed during fermentation. A diversion wall 9 is installed along the length of the middle of the fermentation tank 1, with gaps between the two ends of the diversion wall 9 and the end walls of the fermentation tank 1. A recessed secondary tank 12 is located at one end of the fermentation tank in the gap. The fermentation tank 1 forms a biogas slurry circulation channel 14 on both sides and at both ends of the diversion wall. A waterwheel 10 is installed in the circulation channel 14 to drive the biogas slurry flow. The waterwheel uses a rotating shaft to drive the impeller to pump water. Four waterwheels are movable, with two waterwheels on each side of the diversion wall. An aeration pipe 11 is also provided on the bottom surface of the fermentation tank 1. The aeration pipe is arranged in a serpentine pattern, and the aeration pump is located on the outside of the fermentation tank 1. An inlet pipe 4 is provided above the secondary tank 12 of the fermentation tank 1. An outlet pipe 5 is provided in the secondary tank. A drug delivery pipe 6 for adding compound microbial agents is also provided above the secondary tank.

[0031] The diversion wall 9 is equipped with a millimeter-wave radar (not shown in the figure) for monitoring the foam height in the fermentation tank. The top of the diversion wall 9 is also equipped with several nozzles 13 for spraying and defoaming. The nozzles are evenly spaced and are umbrella-shaped nozzles with 360-degree spray. The nozzles 13 are connected to a spray pump, which draws biogas slurry from the fermentation tank for spraying.

[0032] like Figure 1As shown, an ammonia recovery device 8 is also installed on the exterior of the fermentation tank 1 opposite to the door 3. The ammonia recovery device includes a spray tower. A suction pump, drawing air from above the fermentation tank inside the greenhouse, is connected to one side of the bottom of the spray tower. An exhaust pipe is located at the top of the spray tower. A water tank is located below the interior of the spray tower. Multiple spray pipes are installed above the interior of the spray tower. A circulation pump is installed between the water tank and the spray pipes. The water tank also has a return pipe connected to the fermentation tank. An ammonia concentration sensor is also installed in the water tank. The suction capacity of the ammonia recovery device 8 is not less than the aeration capacity of the aeration pipe 11.

[0033] The main body of this device is a fermentation tank, which is 50 m long, 8 m wide, and 4 m deep, with a total volume of 1600 m³. 3 Rated volume 1000 m³ 3 At the right end of the main pool is a secondary pool measuring 8 m long, 4.5 m wide, and 0.5 m deep, which facilitates the cleaning of sludge sediment. The feed inlet (including the liquid inlet pipe, drug delivery pipe, and clear water pipe) is located at the top of the right end, with a flow rate of 1-2 m³ / h. 3 The feed rate is 1-2 m³ / min, the feed temperature is 25 ℃, and the outlet is located in the bottom secondary tank on the right side. 3 The fermentation tank has a diversion wall in the middle, with both ends 4.5 m away from the tank wall. The diversion wall is at least 300 mm thick, with a permeability grade of at least P6. The inner wall surface must be covered with a waterproof layer and an insulation layer, possessing Class I waterproof performance. The outer wall has an anti-collapse design. A standard steel pipe greenhouse, 3.2 m high, is built above the fermentation tank. The tank is completely sealed and covered with high-quality 10-mil PE film to reduce energy loss and ensure sufficient light to promote the growth of photosynthetic bacteria. One layer of film is used in summer, and two layers in winter. There are four sets of waterwheels in the fermentation tank, which are suspended and movable. Two sets of aeration pipes are set in parallel, and the aeration pipes are connected to the aeration pump, which is located outside the fermentation tank. A spray pump is installed in the fermentation tank, and the spray pump is connected to the spray nozzles through spray pipes. A sludge pump is also installed in the secondary tank to clean up the sludge accumulated after long-term use.

[0034] The fermentation broth produced by this device adopts the following process flow:

[0035] On the first day, add 2 tons of compound microbial agent, 8 tons of clean water, and 8 tons of biogas slurry to a secondary fermentation tank. Move the water truck to the secondary tank and start it. Control the biogas slurry temperature at 25-35 ℃. After running for 2 days, the biogas slurry turns red and has almost no odor.

[0036] On the third day, 24 tons of clean water and 24 tons of biogas slurry were added to the fermentation tank, and the aeration pipe in the fermentation tank was started and operated for 2 days.

[0037] Starting on day 5, 25 tons of biogas slurry are added every 3 hours; at this time, the mobile water truck is moved and positioned in the circulation channel and activated.

[0038] Starting from the 9th day, the process continues until the fermentation tank has accumulated 1000 cubic meters of biogas slurry, at which point the inflow and outflow of biogas slurry is stopped, and the process is repeated for 3 days.

[0039] Starting from the 12th day, the fermentation tank produces 10-15 tons of biogas slurry every 3 hours during the day as fermentation liquid product, and then replenishes it with an equal amount of biogas slurry, with the output going out first and the input coming in later.

[0040] The compound microbial agent, by weight, includes 20 parts of Bacillus subtilis, 20 parts of potassium-solubilizing bacteria, 20 parts of phosphorus-solubilizing bacteria, 10 parts of EM photosynthetic bacteria, 10 parts of lactic acid bacteria, 10 parts of yeast, and 10 parts of nitrifying bacteria.

[0041] During the fermentation process, when the millimeter-wave radar on the diversion wall of the fermentation tank detects that the height of the biogas slurry foam is less than 1 meter from the top of the fermentation tank, the spray pump and nozzles are started for 10-15 minutes to spray and defoam. The biogas slurry in the fermentation tank is used for spraying.

[0042] The ammonia recovery device starts synchronously with the aeration pipe. The spray liquid of the ammonia recovery device is clean water. When the ammonia concentration in the water tank in the spray tower exceeds 80% of the saturation concentration, the water in the water tank is replaced and the water in the water tank is discharged into the fermentation tank.

[0043] The following are the comparative results of the biogas slurry testing before and after using this production device and method (samples taken from the original biogas slurry tank before fermentation, and fermentation liquid output from the fermentation tank after fermentation).

[0044] (1) Changes in malodorous gaseous pollutants

[0045]

[0046] *Odor concentration was determined using the three-point comparison odor bag method, referring to GB / T 14675-93; NH3 and H2S concentrations were measured on-site using a Ventis Pro 5 multi-gas detector with a resolution of 1 ppm.

[0047] (2) Changes in the content of five heavy metals

[0048]

[0049] *The methods for determining total arsenic, total mercury, total lead, total cadmium, and total chromium are in accordance with GB / T 23349-2020.

[0050] (3) Changes in fecal coliforms and roundworm eggs

[0051]

[0052] *The method for determining fecal coliform counts refers to HJ 347.2-2018, and the method for determining ascarid eggs refers to HJ 775-2015.

[0053] (4) Changes in nutrients

[0054]

[0055] *Organic matter, total nutrients, nitrogen, phosphorus and potassium are all calculated on a dried basis, and the determination method is in accordance with NY / T 525-2021; the determination method for trace elements copper, iron, manganese, zinc, boron and molybdenum is in accordance with NY / T 1428-2010.

[0056] (5) Changes in substances such as amino acids

[0057]

[0058] The fermentation broth used in this example was used to conduct a rice experiment. The experimental process and results are as follows.

[0059] I. Application Method:

[0060] This rice experiment began after the rice tillers and the fermentation liquid was applied three times: (1) on the afternoon of August 7, 2021, by foliar spraying; (2) on the afternoon of August 25, 2021, by irrigation; and (3) on the afternoon of September 16, 2021, by foliar spraying.

[0061] Seven treatments were set up: (1) conventional fertilization; (2) conventional fertilization + 15 times dilution; (3) conventional fertilization + 30 times dilution; (4) conventional fertilization + 45 times dilution; (5) no fertilizer + 15 times dilution; (6) no fertilizer + 30 times dilution; (7) no fertilizer + 45 times dilution. Each treatment was repeated 3 times, for a total of 21 plots, 18m 2 / district.

[0062] Table 1. Details of Fermentation Fermentation Fermentation Application for Each Treatment

[0063]

[0064] II. Production Results:

[0065] As shown in Table 2, compared with conventional fertilization treatments, the conventional fertilization + 15-fold dilution and conventional fertilization + 30-fold dilution treatments both increased rice yield by 5.61%. The conventional fertilization + 45-fold dilution treatment had essentially the same yield as conventional fertilization. Compared with conventional fertilization treatments, the no-fertilizer + 15-fold dilution treatment had virtually no effect on rice yield; the no-fertilizer + 30-fold dilution treatment reduced rice yield to some extent, by 1.99%; and the no-fertilizer + 45-fold dilution treatment significantly reduced rice yield, by 7.23%.

[0066] Table 2. Yields of each treatment

[0067]

[0068] III. Conclusion:

[0069] The conclusion of this experiment is that, on the basis of conventional fertilization, applying 19.9-39.4 liters / mu of fermented liquid is beneficial to increasing rice yield; under the condition of no chemical fertilizer application, applying 39.4 liters / mu of fermented liquid can basically maintain the same level of rice yield as under conventional fertilization.

Claims

1. A fermentation broth production device based on biogas slurry, comprising a fermentation tank, characterized in that: A greenhouse is erected above the fermentation tank, and the greenhouse is covered with a light-transmitting plastic film. A diversion wall is set in the middle of the fermentation tank along its length, with gaps between the two ends of the diversion wall and the end wall of the fermentation tank. A recessed secondary tank is set at one end of the fermentation tank. The fermentation tank forms a biogas slurry circulation channel on both sides and at both ends of the diversion wall. A waterwheel is set on the circulation channel to drive the flow of biogas slurry. An inlet pipe is set above the secondary tank of the fermentation tank, and an outlet pipe is set in the secondary tank. A drug delivery pipe for adding compound microbial agents is also set above the secondary tank. An ammonia recovery device is also installed on the exterior of one side of the fermentation tank. The ammonia recovery device includes a spray tower, with an air pump connected to the bottom of the spray tower to draw air from above the fermentation tank inside the greenhouse. An exhaust pipe is installed at the top of the spray tower, and a water tank is located at the bottom inside the spray tower. Multiple spray pipes are installed at the top inside the spray tower, and a circulation pump is installed between the water tank and the spray pipes. The water tank is also equipped with a return pipe connected to the fermentation tank. The spray liquid of the ammonia recovery device is clean water. When the ammonia concentration in the water tank inside the spray tower exceeds 80% of the saturation concentration, the water in the water tank is replaced, and the water in the water tank is discharged into the fermentation tank. The air pump of the ammonia recovery device has an air extraction capacity that is not less than the aeration capacity of the aeration pipe. The diversion wall is equipped with a millimeter-wave radar to monitor the foam height in the fermentation tank. The top of the diversion wall is also equipped with several spray nozzles for defoaming. When the foam is higher than a certain height, the spray nozzles are activated to spray the fermentation tank in full coverage to defoam. At the same time, the sprayed water mist dissolves the ammonia gas volatilized in the air back into the biogas slurry.

2. The fermentation broth production device based on biogas slurry according to claim 1, characterized in that: The fermentation tank is connected to a transfer tank via an inlet pipe at its front side. The transfer tank is connected to the biogas slurry source tank via a delivery pipe at its front side. An ozone generator for ozone sterilization is connected to the side of the delivery pipe.

3. The fermentation broth production device based on biogas slurry according to claim 1, characterized in that: The pool is also equipped with an ammonia concentration sensor.

4. The fermentation broth production device based on biogas slurry according to claim 1, characterized in that: Waterwheels are installed on both sides of the diversion wall in the circulation channel. Each waterwheel pumps water in a clockwise or counterclockwise direction. The waterwheels are movable along the circulation channel.

5. The fermentation broth production device based on biogas slurry according to claim 1, characterized in that: The bottom of the fermentation tank is also equipped with several aeration pumps or aeration pipes.

6. A method for producing fermentation broth based on biogas slurry, using the production apparatus as described in claim 1, characterized in that: The process includes the following steps: On the first day, fill the secondary tank of the fermentation tank with 1-3 parts compound microbial agent, 6-10 parts clean water and 6-10 parts biogas slurry. Move the water truck to the secondary tank and start it. Control the biogas slurry temperature at 25-35 ℃. After running for 2 days, the biogas slurry turns red and has almost no odor. On the third day, add 20-30 parts clean water and 20-30 parts biogas slurry to the fermentation tank, start the aeration pump or aeration pipe in the fermentation tank, and run it for 2 days. Starting on the 5th day, add 20-30 portions of biogas slurry every 3 hours; at this time, the mobile water truck is evenly distributed in the circulation channel and started until the fermentation tank is filled with 1000-1200 portions of biogas slurry, then stop adding and removing biogas slurry, and run for 3-5 days; During the day, the fermentation tank produces 10-15 portions of biogas slurry every 3 hours as fermentation liquid product, and then replenishes an equal amount of biogas slurry, with the output going out first and the input coming in later. The ammonia recovery device is started before the fermentation tank accumulates 1000-1200 parts of biogas slurry. The spray liquid of the ammonia recovery device is clean water. When the ammonia concentration in the water tank in the spray tower exceeds 80% of the saturation concentration, the water in the water tank is replaced and the water in the water tank is discharged into the fermentation tank. The air pump of the ammonia recovery device is not less than the aeration volume of the aeration pipe. Millimeter-wave radar and nozzles are installed on the diversion wall of the fermentation tank. When the height of the biogas slurry foam is less than 1-1.2 meters from the top of the fermentation tank, the nozzles are activated for 10-15 minutes to spray and defoam. The biogas slurry in the fermentation tank is used for spraying.

7. A method for producing fermentation broth based on biogas slurry according to claim 6, characterized in that: The compound microbial agent, by weight, includes 20 parts of Bacillus subtilis, 20 parts of potassium-solubilizing bacteria, 20 parts of phosphorus-solubilizing bacteria, 10 parts of EM photosynthetic bacteria, 10 parts of lactic acid bacteria, 10 parts of yeast, and 10 parts of nitrifying bacteria.

8. A method for producing fermentation broth based on biogas slurry according to claim 6, characterized in that: During the process of transferring biogas slurry from the original digester to the transfer digester, 40g of ozone is mixed with every 5 tons of biogas slurry to kill fecal coliforms and roundworm eggs. Before the first injection of liquid into the fermentation digester, the transfer digester is continuously aerated for at least 48 hours. After each subsequent injection of liquid into the fermentation digester, an equal amount of liquid is taken from the transfer digester, and the amount of liquid taken each time does not exceed 1 / 15 of the capacity of the transfer digester.

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