Combined anaerobic fermentation system and fermentation method based on hydraulic stirring of jet nozzle

Abstract

The present application relates to the technical field of excrement treatment, in particular to a full-mixing and plug-flow combined anaerobic fermentation system and method based on hydraulic stirring of a jet nozzle, comprising: a fermentation tank for receiving fresh material to be fermented, a sand collecting pit is arranged at the bottom of the tank body of the fermentation tank, a slope surface is formed between the sand collecting pit and the side wall of the tank body of the fermentation tank, and a sand discharging pipe is further arranged in the sand collecting pit for discharging the sand and mud in the sand collecting pit out of the fermentation tank. In the present application, the material in the combined fermentation system of the fermentation tank and the plug-flow tank becomes an organic whole under the action of the circulating pump, the plug-flow tank with low cost provides most of the fermentation volume, and the full-mixing fermentation tank with high cost, mixing, heating and easy sand and mud discharge only needs to provide a suitable and small fermentation volume. The two complement each other's advantages and overcome each other's disadvantages, and become an energy-saving, efficient and reliable combined fermentation process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of fecal treatment, in particular to a full-mix and plug-flow combined anaerobic fermentation system based on hydraulic agitation of jet flow nozzle and a fermentation method. BACKGROUND

[0002] The typical process for fecal treatment in modern large-scale lactating cow farms is to produce biogas through anaerobic fermentation, to send the purified biogas to an internal combustion generator for power generation, and to apply the fermented biogas slurry to farmland.

[0003] Through the practice and exploration of large and medium-sized biogas projects in the world in recent years, it is proved that the more successful fecal fermentation process technologies include full-mix anaerobic process, plug-flow anaerobic fermentation tank, up-flow sludge bed, and up-flow anaerobic sludge bed process. In actual engineering applications, the full-mix anaerobic process and the plug-flow anaerobic fermentation process, which are both medium-temperature (37-40℃) fermentation processes, occupy an absolute dominant position.

[0004] In these two processes, the plug-flow anaerobic fermentation process has lower cost and energy consumption, but has the disadvantages of lower biogas production rate and difficulty in discharging sludge. The full-mix anaerobic process has relatively higher cost and energy consumption, but has significantly higher biogas production rate due to uniform fermentation temperature and material mixing, and relatively easy sludge discharge. It is proved that the full-mix anaerobic process has better investment economy.

[0005] For a lactating cow farm with more than 10,000 heads, the appropriate anaerobic fermentation volume is about 20,000 m 3 The larger the volume, the greater the biogas production, but the higher the cost. The unit volume cost level (including heating and stirring system) of the plug-flow fermentation tank is about 600 yuan / m3; and the unit volume cost level of the full-mix anaerobic process fermentation tank is 900 yuan / m3. The above cost levels do not include foundation treatment costs. If the natural foundation bearing capacity is low (~10 t / m2), the cost of the full-mix process fermentation tank will be higher because the liquid level of the fermentation tank is generally more than 20 meters, the unit load is large, and the foundation needs to be treated to meet the load requirements.

[0006] In summary, it is of practical significance to make the anaerobic fermentation system have cost and energy consumption comparable to that of the plug-flow type, and have biogas production rate comparable to that of the full-mix type. SUMMARY

[0007] In view of the technical problems existing in the prior art of fecal anaerobic fermentation treatment technology, the first aspect of the present application proposes a full-mix and plug-flow combined anaerobic fermentation system based on hydraulic agitation of jet flow nozzle, comprising:

[0008] A fermentation tank is used to receive fresh materials to be fermented. The bottom of the fermentation tank is provided with a sand collection pit. A slope is formed between the upper edge of the sand collection pit and the side wall of the fermentation tank. A sand discharge pipe is also provided in the sand collection pit to discharge the mud and sand in the sand collection pit from the fermentation tank.

[0009] A hydraulic mixing component is positioned above the slope.

[0010] A liquid suction component is installed inside the fermenter and positioned at a specified liquid level. When the biogas slurry in the fermenter reaches the specified height, it flows out of the fermenter through the liquid suction component.

[0011] A flow-generating tank is used to receive the biogas slurry discharged by the liquid-absorbing component;

[0012] The push-flow pool is equipped with a push-flow channel. The feed area of ​​the push-flow channel is connected to the liquid suction component, the discharge area of ​​the push-flow channel is connected to the liquid supply end of the circulation pump, and the discharge end of the circulation pump is connected to the hydraulic stirring component, so that the biogas slurry overflowing from the fermentation tank circulates in the push-flow pool and the fermentation tank.

[0013] Preferably, the hydraulic mixing component includes multiple sets of nozzles, which are connected to the output end of the circulating pump via a liquid supply pipe. The nozzles face the slope, and the biogas slurry ejected by the nozzles can act on the area of ​​the slope surface.

[0014] Preferably, the multiple sets of nozzles are arranged in a centrally symmetrical manner, and the areas of each nozzle in each set that act on the slope surface have overlapping areas.

[0015] Preferably, the liquid-absorbing component is configured in a funnel shape, with its diameter gradually decreasing from the top to the bottom.

[0016] Preferably, the bottom of the liquid suction component is provided with an overflow pipe, and the second end of the overflow pipe is connected to the feeding area of ​​the push flow tank. The biogas slurry in the overflow pipe enters the feeding area from the liquid suction component by gravity.

[0017] Preferably, the feeding area and the flow channel of the flow tank are separated by an overflow plate, and the discharge area and the flow channel of the flow tank are also separated by an overflow plate.

[0018] Preferably, the flow channel is divided into a U-shaped channel by a wall, and the wall is equipped with a heating component to keep the biogas slurry in the flow channel within a preset temperature range.

[0019] Preferably, the flow channel is provided with a stirring component, which includes an aeration pipe connected to a compressed biogas source for introducing compressed biogas into the bottom of the flow channel.

[0020] Preferably, the top of the fermenter is provided with a double-layer gas film, forming a gas storage area in the region above the liquid level and below the double-layer gas film.

[0021] The second aspect of this invention proposes a technical solution: a combined anaerobic fermentation method based on hydraulic stirring with a jet nozzle and total mixing and flow, characterized in that, using the aforementioned anaerobic fermentation system, the method includes the following steps:

[0022] Step 1: Feed fresh material into the fermentation tank intermittently or continuously, allowing the material to accumulate in the fermentation tank;

[0023] Step 2: When the biogas slurry accumulates to the height of the liquid-absorbing component, it flows into the push flow tank by gravity, allowing the biogas slurry to continue fermenting and producing gas in the push flow tank.

[0024] Step 3: Pump the biogas slurry in the push pool back to the bottom of the fermentation tank using a circulating pump. Use nozzles to spray jets onto the slope at the bottom of the fermentation tank to create agitation, so that the fresh material and the returned biogas slurry are mixed.

[0025] In step 3, the circulating pump operates intermittently.

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] In this application, the materials in the combined fermentation system of the fermenter and the plug flow tank become an organic whole under the action of the circulating pump. The plug flow tank, which has a low cost, provides the majority of the fermentation volume, while the total mixing fermenter, which has a higher cost but facilitates mixing, heating, and easy sludge removal, only provides a suitable and smaller fermentation volume. The two complement each other's advantages and overcome each other's disadvantages, resulting in an energy-saving, efficient, and reliable combined fermentation process. There are no rotating parts in the entire fermentation system, and the internal fixed parts are not easily damaged. Therefore, the entire process system has high reliability and can ensure the continuous operation of the combined anaerobic fermentation process system for many years without the need for shutdown and maintenance. Attached Figure Description

[0028] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0029] Figure 1 This is a schematic diagram of the structure of the fully mixed, plug-flow combined anaerobic fermentation system based on hydraulic stirring with a jet nozzle, as shown in the invention.

[0030] Figure 2 This is a schematic diagram of the structure of the fermenter shown in this invention;

[0031] Figure 3This is a schematic diagram showing the distribution of the nozzles at the bottom of the fermenter as described in this invention. Detailed Implementation

[0032] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0033] It should be understood that this application is based on an anaerobic fermentation system for dairy farms with more than 10,000 dairy cows, and the volume of such a fermentation system is approximately 20,000 m³. 3 While conventional plug-flow fermenters offer advantages in terms of low cost and are suitable for anaerobic fermentation of cow manure, such large-scale feeding results in higher sediment accumulation at the bottom compared to conventional plug-flow fermenters, impacting the reactor's effective volume and reaction efficiency, thus necessitating subsequent maintenance and cleaning. Furthermore, fully mixed anaerobic fermentation requires fermentation tanks, whose large capacity leads to extremely high construction costs and a significantly increased need for agitation equipment, further escalating maintenance and operating costs. Therefore, addressing these challenges, this application aims to provide an anaerobic fermentation system with relatively low construction and operating costs and high gas production.

[0034] The inventors hoped to utilize the low-cost advantage of the plug flow tank to create a large-capacity fermentation space. However, achieving a high gas production rate requires controlling the feed into the plug flow tank. Therefore, the inventors designed a combined anaerobic fermentation system of full mixing and plug flow, taking advantage of the full mixing process. The feed is first treated using the full mixing process to remove mud and sand from the material, and the material discharged into the plug flow tank is already at the ideal fermentation temperature, avoiding the problems of the plug flow tank itself being difficult to heat and uneven heating.

[0035]

A combined anaerobic fermentation system based on hydraulic stirring with jet nozzles and total mixing

[0036] Combination Figures 1-2 As shown, the first aspect of the present invention proposes a fully mixed and plug-flow combined anaerobic fermentation system based on hydraulic stirring with a jet nozzle, including a fermenter 10, a hydraulic stirring component 20, a liquid suction component 30, and a plug-flow pool 40. The fermenter 10 is used to receive fresh materials to be fermented. The bottom of the fermenter 10 is provided with a feed pipe for conveying fresh materials to the bottom of the fermenter 10. The bottom of the fermenter 10 is provided with a sand collection pit 11. A slope 12 is formed between the upper edge of the sand collection pit 11 and the side wall of the fermenter 10. A sand discharge pipe 111 is also provided in the sand collection pit 11 for discharging the mud and sand in the sand collection pit 11 from the fermenter 10.

[0037] During the process of material being transported into fermentation tank 10 and continuously accumulating upwards, anaerobic reaction occurs. In this process, scum floats upwards and accumulates on top of the biogas slurry. Long-term accumulation may cause hardening and crusting, while mud and sand accumulate at the bottom, compressing the volume inside the fermentation tank. Furthermore, the hydraulic stirring component 20 is set above the slope 12, and the liquid suction component 30 is set inside fermentation tank 10 at a specified liquid level. When the biogas slurry in fermentation tank 10 reaches the specified height, it flows out of fermentation tank 10 through the liquid suction component 30.

[0038] In this way, the mud and sand in the material are collected in a concentrated manner and discharged from the fermentation tank 10 at regular intervals, which can maintain the effective volume of the fermentation tank 10. The liquid suction component 30 maintains the height of the biogas slurry surface and continuously allows the biogas slurry surface to flow, thereby achieving the shell-breaking effect and avoiding the accumulation of scum.

[0039] In an optional embodiment, the slope 12 is an 8-12° centripetal gentle slope set at the bottom of the fermenter 10.

[0040] Furthermore, in combination Figures 2-3 As shown, the hydraulic mixing component 20 includes multiple sets of nozzles 201. The nozzles 201 are connected to the output end of the circulating pump 21 via a liquid supply pipe 211. The nozzles 201 face the slope 12, and the biogas slurry ejected by the nozzles 201 can act on the surface area of ​​the slope 12. In this way, the high-velocity liquid at the outlet of the nozzles 201 impacts downwards, and each nozzle 201 can cover an area of ​​more than 10 square meters, creating a strong local hydraulic mixing effect.

[0041] Preferably, the multiple sets of nozzles 201 are arranged in a centrally symmetrical manner, and the areas of each nozzle in each set of nozzles 201 that act on the surface of the slope 12 overlap with each other. By pumping liquid sequentially to each set of nozzles 201 through the circulating pump 21, continuous stirring can be formed in different areas at the bottom of the fermentation tank 10, and the silt accumulated on the slope 12 is gradually driven to the sand collection pit 11. The bottom of the sand collection pit 11 is equipped with four sand discharge pipes 111. The silt in the sand collection pit 11 is discharged to the outside of the fermentation tank 10 through the sand discharge pipes 111 by the pressure of the biogas slurry.

[0042] Furthermore, the liquid suction component 30 is configured in a funnel shape, with its diameter gradually decreasing from top to bottom. This enlarged funnel shape reduces the liquid flow rate at the suction inlet, thus reducing the amount of biogas entrained in the liquid.

[0043] Combination Figure 2 As shown, the top of the fermenter 10 is provided with a double-layer gas film 13, and a gas storage area 103 is formed in the area above the liquid level of the fermenter 10 and below the double-layer gas film 13.

[0044] In this way, the biogas produced in the fermentation tank 10 can be stored in the gas storage area 103 without the need to build a separate gas holder, thus saving space.

[0045] Furthermore, the push-flow tank 40 is used to receive the biogas slurry discharged by the liquid suction component 30. In an optional embodiment, the volume ratio of the fermentation tank 10 to the push-flow tank 40 can be approximately 1:9, satisfying a capacity of 20,000 m³. 3 The required volume.

[0046] Specifically, fermentation tank 10 has a diameter of 9-10 meters, a height of about 20 meters, and a volume of 1500-2000 m³. 3 .

[0047] Combination Figure 1 As shown, the push flow tank 40 is provided with a push flow channel 402. The feed area 401 of the push flow channel 402 is connected to the liquid suction component 30, and the discharge area 403 of the push flow channel 402 is connected to the liquid supply end of the circulation pump 21. The discharge end of the circulation pump 21 is connected to the hydraulic stirring component 20, so that the biogas slurry overflowing from the fermentation tank 10 circulates in the push flow tank 40 and the fermentation tank 10.

[0048] Optionally, the bottom of the liquid suction component 30 is provided with an overflow pipe 31, and the second end of the overflow pipe 31 is connected to the feeding area 401 of the push flow tank 40. The biogas slurry in the overflow pipe 31 enters the feeding area 401 from the liquid suction component 30 by gravity.

[0049] It should be understood that anaerobic reactions consist of three stages. The first stage is the contact stage, where organic matter (fresh raw materials) comes into contact with microorganisms (such as bacteria and archaea) at the beginning of the anaerobic reaction. The purpose of this stage is to ensure thorough mixing of the substrate and microorganisms so that subsequent reactions can proceed smoothly. The contact stage usually requires a certain amount of time because substrate molecules need to bind to the surface of the microorganisms to form a reaction interface.

[0050] The second stage is the acidification stage, characterized by the breakdown of the substrate into smaller organic acid molecules. These organic acid molecules can be those produced after the contact stage, such as acetic acid and propionic acid. The acidification stage requires a certain amount of time because the breakdown of the substrate involves a series of enzymatic reactions. During the acidification stage, microorganisms utilize the substrate as an energy source for metabolism, while simultaneously producing byproducts such as carbon dioxide and some organic compounds. These byproducts further promote the anaerobic reaction.

[0051] The third stage is the gas-producing stage. After the acidification stage, the decomposition products of the substrate are further metabolized by microorganisms, producing a large amount of gas. This stage is called the gas-producing stage. The main characteristic of the gas-producing stage is that the substrate decomposition rate increases, and the gas production rate also increases. During the gas-producing stage, the anaerobic reaction rate reaches its maximum. At this point, the produced gas gradually accumulates in the reaction system, generating pressure. When the pressure reaches a certain value, the reaction enters an equilibrium state, and the reaction rate no longer increases.

[0052] In this application, after the fresh material in the fermenter 10 completes the first and second stages of anaerobic reaction, it enters the feed zone 401 of the plugging tank 40 through the overflow pipe 31. Since the fermenter 10 has sufficient heating area to heat all the fresh material to the target temperature, the material temperature entering the plugging tank has reached the target value. At the same time, due to the accelerated flow and replacement of biogas slurry in the plugging tank, the temperature uniformity is well guaranteed. Therefore, the biogas slurry entering the plugging tank 40 is at a higher temperature, which can reduce the energy consumption of the heating components arranged in the plugging tank 40. Furthermore, the biogas slurry entering the plugging tank 40 is in the third stage of fermentation, which does not require a hydrolysis and acidification section. The reaction efficiency in the plugging tank 40 is higher, and no mud or sand is introduced into the plugging tank 40. Moreover, the biogas slurry after reaction in the plugging tank 40 can be ejected into the bottom of the fermenter 10 through the recycling nozzle 201 of the circulation pump 21. This allows it to mix with the fresh material, promotes the decomposition of the fresh material, and prevents the waste of microorganisms.

[0053] Furthermore, the feed area 401 and the push channel 402 of the push pool 40 are separated by an overflow plate 43, and the discharge area 403 and the push channel 402 of the push pool 40 are also separated by an overflow plate 43.

[0054] In this way, when the biogas slurry flowing out of the fermentation tank 10 first enters the feeding area 401 and accumulates until it reaches the overflow level, it then enters the push channel 402 of the push pool 40. After accumulating in the push channel 402, it enters the discharge area 403, thus preventing the low-temperature biogas slurry from flowing back into the fermentation tank 10 and ensuring that the temperature of each point in the fermentation tank 10 and the push pool 40 is balanced during normal operation.

[0055] Combination Figure 1 As shown, the push pool 40 is divided into two push channels 402, each push channel 402 corresponding to a feed area 401. The overflow pipe 31 has a branch pipe in each feed area 401, and a valve is provided on the branch pipe. In this way, it can first enter one push channel 402. When one push channel 402 is full, it can then enter the other push channel 402, and then keep the two push channels 402 running synchronously.

[0056] Furthermore, the overflow pipe 31 is also connected to a branch pipe in the discharge area 403 and is equipped with a separate valve so that some of the overflowing biogas slurry enters the discharge area 403. A liquid extraction pipe 22 is provided between the circulation pump 21 and the discharge area 403, so that the biogas slurry in the discharge area 403 can be pumped by the circulation pump 21 and circulated to the bottom of the fermentation tank 10.

[0057] In an optional embodiment, the push channel 402 is divided into a U-shaped channel by a wall 41, and a heating component is provided in the wall 41 to keep the biogas slurry in the push channel 402 within a preset temperature range.

[0058] Among them, a biogas collection device is set around the push flow pool 40 and connected to the push flow channel 402, and a portion of the collected biogas can be compressed and injected into the push flow channel 402 to stir the biogas slurry.

[0059] Furthermore, to promote the reaction of materials in the flow channel 402, a stirring component is provided in the flow channel 402. The stirring component includes an aeration pipe connected to a compressed biogas source for introducing compressed biogas into the bottom of the flow channel 402. The bubbles formed by the compressed biogas create a stirring effect in the biogas slurry, promoting contact between materials and improving reaction efficiency.

[0060] [A combined anaerobic fermentation method based on hydraulic stirring with a jet nozzle and total mixing and plug flow]

[0061] The second aspect of this invention proposes a technical solution: a combined anaerobic fermentation method based on hydraulic stirring with a jet nozzle and total mixing and flow, characterized in that, using the aforementioned anaerobic fermentation system, the method includes the following steps:

[0062] Step 1: Feed fresh material into the fermentation tank 10 intermittently or continuously, so that the material accumulates in the fermentation tank 10.

[0063] Step 2: When the biogas slurry accumulates to the height of the liquid absorption component 30, it flows into the push flow tank 40 by gravity, allowing the biogas slurry to continue to ferment and produce gas in the push flow tank 40.

[0064] Step 3: The biogas slurry in the push pool 40 is pumped back to the bottom of the fermentation tank 10 by the circulation pump 21, and the spray nozzle 201 is used to launch a jet onto the slope 12 at the bottom of the fermentation tank 10 to form a stirring, so that the fresh material and the returned biogas slurry are mixed.

[0065] In step 3, the circulating pump 21 operates intermittently.

[0066] In an optional embodiment, when the biogas slurry accumulates to the height of the liquid-absorbing component 30, it flows into the push flow tank 40 by gravity. In particular, it first enters the feeding area 401 through the overflow pipe 31 and is preferentially fed to one of the push flow channels 402. Part of the biogas slurry in the overflow pipe 31 is discharged into the discharge area 403 for use by the circulating pump 21 when pumping and stirring.

[0067] Combination Figure 3As shown, it includes six sets of nozzles 201. Each set of nozzles 201 is connected to the circulation pump 21 via a liquid supply pipe 211. Each set contains five nozzles 201, and each nozzle 201 covers an area of ​​10 square meters. The circulation pump 21 runs continuously for one hour every two hours. Each set of nozzles 201 sprays continuously for 10 minutes. The six sets of nozzles spray in sequence to ensure the spray pressure of each set of nozzles. The jets ejected from the nozzles 201 can sweep away the mud and sand accumulated on the slope 12 and drive them into the sand collection pit 11 for discharge. At the same time, the large-scale jets can mix with the fresh materials at the bottom.

[0068] Furthermore, biogas slurry temperature detection points are set at different heights inside the fermentation tank 10. By detecting the temperature, the flow rate of feed and return biogas slurry is controlled to maintain temperature uniformity at each point.

[0069] In conjunction with the above embodiments, in this application, only one circulating liquid supply pump is installed outside the fermenter. Each group of spray branch pipes is connected to the outlet ring pipe of the circulating liquid supply pump. Each group of nozzles is controlled by an automatic valve. The rotating machinery consists only of the pump and the automatic valve, which are installed outside the tank body, making them easy to inspect and replace. The facilities inside the tank are all fixed components (pipes, turbulent nozzles), which are not easily damaged. Therefore, the entire process system has high reliability and can ensure that the anaerobic tank can operate continuously for many years without shutdown for maintenance. Moreover, the operating energy consumption is significantly lower than that of the total mixed fermenter process.

[0070] The biogas slurry inside the push pool and fermentation tank is mixed together by the biogas slurry circulation pump, and can be circulated once every 1-2 days, so as to achieve uniform mixing of materials and temperature and improve the fermentation gas production rate.

[0071] All fresh materials are added to the total mixed fermentation tank, where they are continuously heated to the ideal fermentation temperature. The plug-flow fermentation tank only accepts materials overflowing from the total mixed fermentation tank, whose temperature has already reached the ideal fermentation temperature. This simplifies the heating system of the plug-flow fermentation tank, requiring only the maximum heat dissipation in winter, avoiding the inherent disadvantage of uneven heating in plug-flow fermentation tanks, and eliminating the acidification and hydrolysis zone at the feed inlet.

[0072] Since all fresh raw materials are added to the fully mixed fermentation tank, most of the larger particles of mud and sand in the fresh materials accumulate in the mud and sand collection pit of the fully mixed fermentation tank, and can be easily discharged through the mud and sand discharge pipe, which greatly reduces the accumulation of mud and sand in the plugging pool.

[0073] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A combined anaerobic fermentation system based on hydraulic stirring with a jet nozzle, characterized in that, include: Fermentation tank (10) is used to receive fresh materials to be fermented. The bottom of the fermentation tank (10) is provided with a sand collection pit (11). The upper edge of the sand collection pit (11) and the side wall of the fermentation tank (10) form a slope (12) that slopes towards the sand collection pit (11). The sand collection pit (11) is also provided with a sand discharge pipe (111) for discharging the mud and sand in the sand collection pit (11) from the fermentation tank (10). A hydraulic mixing component (20) is disposed above the slope (12); the hydraulic mixing component (20) includes multiple sets of nozzles (201), the nozzles (201) are connected to the output end of the circulating pump (21) through a liquid supply pipe (211), the nozzles (201) face the slope (12), and the biogas slurry ejected by the nozzles (201) can act on the area of ​​the slope (12) surface; the multiple sets of nozzles (201) are arranged in a centrally symmetrical manner, and the areas of each nozzle in each set of nozzles (201) acting on the slope (12) surface have overlapping areas; the jet ejected by the nozzles (201) can sweep away the mud and sand accumulated on the slope (12) and drive it to the sand collection pit (11) for discharge, while the large-scale jet can mix with the fresh material at the bottom; A liquid-absorbing component (30) is installed inside the fermentation tank (10) and is at a specified liquid level. When the biogas slurry in the fermentation tank (10) reaches the specified height, it flows out of the fermentation tank (10) through the liquid-absorbing component (30). The liquid-absorbing component (30) is constructed in the shape of a funnel mouth, with the diameter gradually decreasing from the top to the bottom. A push-flow tank (40) is used to receive the biogas slurry discharged by the liquid suction component (30); The push flow pool (40) is provided with a push flow channel (402). The feed area (401) of the push flow channel (402) is connected to the liquid suction component (30). The discharge area (403) of the push flow channel (402) is connected to the liquid supply end of the circulation pump (21). The discharge end of the circulation pump (21) is connected to the hydraulic stirring component (20), so that the biogas slurry overflowing from the fermentation tank (10) circulates in the push flow pool (40) and the fermentation tank (10). The feeding area (401) and the pushing channel (402) of the pushing pool (40) are separated by an overflow plate (43), and the discharge area (403) and the pushing channel (402) of the pushing pool (40) are separated by an overflow plate (43). The bottom of the liquid suction component (30) is provided with an overflow pipe (31), and the second end of the overflow pipe (31) is connected to the feeding area (401) of the push flow pool (40). The biogas slurry in the overflow pipe (31) enters the feeding area (401) by gravity from the liquid suction component (30).

2. The fully mixed, plug-flow combined anaerobic fermentation system based on hydraulic stirring with a turbulent nozzle according to claim 1, characterized in that, The push channel (402) is divided into a U-shaped channel by a wall (41), and a heating component is provided in the wall (41) to keep the biogas slurry in the push channel (402) within a preset temperature range.

3. The fully mixed, plug-flow combined anaerobic fermentation system based on turbulent nozzle hydraulic stirring according to claim 1, characterized in that, The push flow channel (402) is equipped with a stirring component, which includes an aeration pipe connected to a compressed biogas source for introducing compressed biogas into the bottom of the push flow channel (402).

4. The fully mixed, plug-flow combined anaerobic fermentation system based on hydraulic stirring with a jet nozzle according to claim 1, characterized in that, The fermenter (10) is provided with a double-layer gas film (13) at the top, and a gas storage area (103) is formed in the area above the liquid level of the fermenter (10) and below the double-layer gas film (13).

5. A combined anaerobic fermentation method based on hydraulic stirring with a jet nozzle, characterized in that, The fully mixed plug flow combined anaerobic fermentation system based on turbulent nozzle hydraulic stirring as described in any one of claims 1-4 includes the following steps: Step 1: Feed fresh material into the fermentation tank (10) intermittently or continuously, so that the material accumulates in the fermentation tank (10); Step 2: When the biogas slurry accumulates to the height of the liquid-absorbing component (30), it flows into the push flow tank (40) by gravity, allowing the biogas slurry to continue to ferment and produce gas in the push flow tank (40); Step 3: The biogas slurry in the push pool (40) is pumped back to the bottom of the fermentation tank (10) by the circulation pump (21), and the spray nozzle (201) is used to launch a jet onto the slope (12) at the bottom of the fermentation tank (10) to form a stirring, so that the fresh material and the returned biogas slurry are mixed. In step 3, the circulating pump (21) operates intermittently.

Images