Novel water-sealed tank of biogas system

Abstract

The invention provides a novel water-sealed tank for a biogas system. The novel water-sealed tank comprises a water-sealed tank body, a detachable top cover, a liquid level meter lower connecting pipe orifice, a liquid level meter upper connecting pipe orifice, a biogas inlet pipe orifice, an air inlet inner extending pipe, a water replenishing pipe orifice, a biogas outlet pipe orifice, a tank bottom pipe orifice, an explosion venting pipe orifice, an overflow pipe orifice, an explosion venting overflow pipe, an in-situ pressure gauge and a detachable bracket. The invention has the following beneficial effects: the detachable top cover can be used for maintenance of equipment; water in the water-sealed tank can be automatically discharged through the explosion venting overflow pipe, and the liquid level is not higher than the set liquid level, so that the biogas generated by the anaerobic reactor can flow under the set water-sealed condition; and redundant replenished water or condensed water brought by biogas is automatically discharged in an overflow manner, so that the risk that the liquid level of a water seal is reduced too much or even the water seal is lost due to misoperation can be effectively avoided, and the daily operation and maintenance workload can be effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of biogas treatment, and in particular relates to a novel water seal tank for a biogas system. Background Art

[0002] During the anaerobic treatment of sewage, the biogas produced by one or more anaerobic reactors needs to be collected into a biogas temporary storage and treatment system. In order to prevent the flame from flowing back to the anaerobic reactor in the event of an accident in the biogas temporary storage and treatment system, and to avoid the safety risks caused by the direct connection of biogas pipelines of different anaerobic reactors, it is necessary to install a water seal tank at the biogas outlet of each anaerobic reactor.

[0003] According to the need of parking for maintenance, a shut-off valve will be installed at the outlet of the water seal tank of different anaerobic reactors. When using a conventional water seal tank, once the outlet shut-off valve is misoperated, the biogas produced by the anaerobic reactor cannot be timely transported to the biogas temporary storage and treatment system or vented through the biogas collection pipeline, and the volume and pressure of the biogas in the water seal tank and the three-phase separator of the anaerobic reactor will rise beyond the normal operating conditions, until the biogas fills the three-phase separator and overflows to the top of the anaerobic reactor and is discharged into the waste gas treatment system. This operating condition, on the one hand, forces the design to use larger buoyancy parameters for equipment design, which increases the project cost. On the other hand, the biogas entering the waste gas treatment system is not conducive to the normal operation of the waste gas treatment system due to the flammability of methane and the toxicity of hydrogen sulfide.

[0004] When the biogas comes out of the three-phase separator of the anaerobic reactor, it will carry some water vapor. After being cooled by the lower temperature environment in the transmission pipeline, the water vapor it carries will condense into liquid. Then, when passing through the water seal tank, part of the liquid water will be intercepted in the water seal tank, causing the water seal height to gradually increase. When using a conventional water seal tank, in order to control the height of the water seal, the operation and maintenance personnel need to manually drain the water regularly. This method has the risk of excessively lowering the liquid level and damaging the water seal in the event of misoperation, and the water seal height in the water seal tank cannot be kept stable, which in turn affects the biogas pressure in the three-phase separator and the operation of the anaerobic reactor. Summary of the invention

[0005] In view of this, the present invention aims to provide a novel water seal tank for a biogas system to solve at least one problem existing in the above-mentioned prior art.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] A novel biogas system water seal tank, comprising a water seal tank body, a detachable top cover, a lower connecting pipe opening of a liquid level gauge, an upper connecting pipe opening of a liquid level gauge, a biogas inlet pipe opening, an inlet inner extension pipe, a water supply pipe opening, a biogas outlet pipe opening, a tank bottom pipe opening, an explosion relief pipe opening, an overflow pipe opening, an explosion relief overflow pipe, an on-site pressure gauge and a detachable bracket. The upper connecting pipe opening of the liquid level gauge and the lower connecting pipe opening of the liquid level gauge are sequentially installed on one side of the water seal tank body from top to bottom, and a detachable top cover is installed on the top of the water seal tank body A biogas inlet pipe, a water supply pipe, a biogas outlet pipe, an on-site pressure gauge and an inner inlet extension pipe are installed on the removable top cover, and the removable top cover is connected to the water seal tank body, and the inner inlet extension pipe is located in the water seal tank body, a tank bottom pipe port is installed at the bottom of the water seal tank body, one side of the tank bottom pipe port is connected with the explosion relief overflow pipe pipeline, an explosion relief pipe port is installed above the explosion relief overflow pipe, an overflow pipe port is installed on one side below the explosion relief overflow pipe, and the explosion relief overflow pipe is installed to one side of the water seal tank body through a removable bracket.

[0008] Furthermore, the lower connecting pipe opening of the liquid level gauge, the upper connecting pipe opening of the liquid level gauge, the biogas inlet pipe opening, the inlet inner extension pipe, the water supply pipe opening, the biogas outlet pipe opening, the tank bottom pipe opening, and the detachable bracket are all connected to the water seal tank body or the detachable top cover or the explosion relief overflow pipe by welding. The explosion relief pipe opening and the overflow pipe opening are all connected to the explosion relief overflow pipe by welding.

[0009] Furthermore, the connection method between the tank bottom pipe outlet and the explosion relief overflow pipe is flange connection, and the connection method between the on-site pressure gauge, the water supply pipe outlet and the detachable top cover is flange connection.

[0010] Furthermore, the water seal tank body and the detachable top cover are made of steel.

[0011] Furthermore, the explosion relief overflow pipe includes pipeline No. 1, pipeline No. 2, pipeline No. 3, pipeline No. 4, pipeline No. 5, pipeline No. 6, pipeline No. 7, pipeline No. 8 and pipeline No. 9. The top of pipeline No. 1 is connected to the pipe opening at the bottom of the tank, the bottom of pipeline No. 1 is connected to one end of pipeline No. 4 through pipeline No. 2 and pipeline No. 3 in sequence, the other end of pipeline No. 4 is connected to pipeline No. 5 and pipeline No. 6 respectively, an explosion relief pipe opening is installed above pipeline No. 5, and pipeline No. 6 is connected to the overflow pipe opening through pipeline No. 7, pipeline No. 8 and pipeline No. 9 in sequence.

[0012] Furthermore, the pipeline No. 1, pipeline No. 2, pipeline No. 3, and pipeline No. 4 are all connected by elbows, and pipeline No. 6, pipeline No. 7, pipeline No. 8, and pipeline No. 9 are all connected by elbows.

[0013] Furthermore, the height H1 of the No. 8 pipeline is not less than 250 mm.

[0014] Furthermore, the length of the inner air inlet extension pipe must meet certain requirements, and the height H2 from the tank bottom should be greater than the pipe diameter and should not be less than 100 mm.

[0015] Furthermore, the sizes of the biogas inlet and outlet should be equal to the diameter of the externally connected biogas pipe.

[0016] Furthermore, the drain pipe opening and the explosion relief overflow pipe should not be smaller than the water supply pipe opening.

[0017] Compared with the prior art, the novel biogas system water seal tank described in the present invention has the following advantages:

[0018] (1) The novel biogas system water seal tank described in the present invention has a removable top cover that can be used for equipment inspection and maintenance. The water in the water seal tank can be automatically discharged through the overflow vent pipe, and the liquid level will not be higher than the set liquid level, so that the biogas produced by the anaerobic reactor can flow under the set water seal conditions. The excess make-up water or condensed water brought in by the biogas is automatically discharged in the form of overflow, which can effectively avoid the risk of excessive reduction of the water seal liquid level or even loss of the water seal due to misoperation, and can also effectively reduce the workload of daily operation and maintenance.

[0019] (2) The present invention discloses a novel water seal tank for a biogas system. The gas in the water seal tank mainly enters subsequent biogas collection and treatment pipelines and equipment through the biogas outlet. When the valve behind the water seal tank is misoperated, the gas can be vented into the air through the explosion-proof overflow pipe, thereby ensuring that the pressure in the biogas inlet pipe is maintained within a relatively stable range and that biogas will not be excessively accumulated in the three-phase separator of the anaerobic reactor until a large amount of biogas is leaked into the waste gas treatment system, thereby affecting the safe and stable operation of the waste gas treatment system.

[0020] (3) The present invention describes a novel biogas system water seal tank, in which the air pressure in the water seal tank is maintained within a relatively stable range, and the maximum value is the pressure corresponding to the height difference from the overflow port of the explosion relief overflow pipe to the lowest point of the pipe. Due to the pressure balance on both sides, this parameter is used to calculate the maximum buoyancy that the anaerobic three-phase separator can generate. Compared with the maximum buoyancy value of the three-phase separator of the previous anaerobic reactor, which uses the overflow of biogas from the bottom of the gas collecting chamber as the maximum buoyancy value calculation point, after adopting the present invention, the maximum buoyancy value will be effectively reduced, thereby effectively reducing the anti-floating engineering workload of the three-phase separator. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 It is a schematic diagram of the overall structure of an embodiment of the present invention;

[0023] Figure 2 This is a schematic diagram of the explosion relief overflow pipe described in an embodiment of the present invention.

[0024] Description of reference numerals:

[0025] 1. Water-sealed tank body; 2. Removable top cover; 3. Lower connecting pipe opening of liquid level gauge; 4. Upper connecting pipe opening of liquid level gauge; 5. Biogas inlet pipe opening; 6. Inlet inner extension pipe; 7. Water supply pipe opening; 8. Biogas outlet pipe opening; 9. Tank bottom pipe opening; 10. Explosion vent; 11. Overflow port; 12. Explosion vent overflow pipe; 121. Pipeline No. 1; 122. Pipeline No. 2; 123. Pipeline No. 3; 124. Pipeline No. 4; 125. Pipeline No. 5; 126. Pipeline No. 6; 127. Pipeline No. 7; 128. Pipeline No. 8; 129. Pipeline No. 9; 13. Local pressure gauge; 14. Removable bracket. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0027] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0028] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0030] like Figure 1 to Figure 2As shown, a novel biogas system water seal tank includes a water seal tank body 1, a detachable top cover 2, a lower connecting pipe opening 3 of a liquid level gauge, an upper connecting pipe opening 4 of a liquid level gauge, a biogas inlet pipe opening 5, an inlet inner extension pipe 6, a water supply pipe opening 7, a biogas outlet pipe opening 8, a tank bottom pipe opening 9, an explosion relief pipe opening 10, an overflow pipe opening 11, an explosion relief overflow pipe 12, an on-site pressure gauge 13, and a detachable bracket 14. The lower connecting pipe opening of the liquid level gauge, the upper connecting pipe opening of the liquid level gauge, the biogas inlet pipe opening, the inlet inner extension pipe, the water supply pipe opening, the biogas outlet pipe opening, the tank bottom pipe opening, and the detachable bracket are all connected to the water seal tank body or the detachable top cover by welding. The explosion relief pipe opening and the overflow pipe opening are both connected to the explosion relief overflow pipe by welding. The detachable top cover is connected to the tank body by a flange. The tank bottom pipe opening and the overflow explosion relief pipe are connected by a flange. The local pressure gauge, water supply pipe port and detachable top cover are connected in the form of flanges. The materials of all the above materials can be selected according to the composition of biogas.

[0031] The water seal tank body 1 and the removable top cover 2 can be made of steel, and the specific size can be adjusted according to the water seal height and the size of the inlet and outlet gas volume; the lower connecting pipe opening 3 of the liquid level gauge, the upper connecting pipe opening 4 of the liquid level gauge, and the tank bottom pipe opening 9 can be welded to the water seal tank body 1 after being processed with pipes and flanges, and are used to install a magnetic flap level gauge with a root valve and a remote transmission function; the biogas inlet pipe opening 5, the inner inlet extension pipe 6, and the biogas outlet pipe opening 8 can be welded to the removable top cover 2 after being processed with pipes and flanges, and the size can be adjusted according to the size of the inlet and outlet gas volume, and the number of pipe openings can be adjusted according to the number of inlet and outlet pipes; the water supply pipe opening 7 and the flanged short section at the bottom of the local pressure gauge 13 are installed on the removable top cover by welding, and the valve and the top short section of the water supply pipe opening 7 as well as the local pressure gauge 13 and its The root valve is connected to the flange of the short section in the form of a flange; the explosion relief overflow pipe 12 includes pipeline No. 121, pipeline No. 2 122, pipeline No. 3 123, pipeline No. 4 124, pipeline No. 5 125, pipeline No. 6 126, pipeline No. 7 127, pipeline No. 8 128 and pipeline No. 9 129. The top of pipeline No. 121 is connected with the pipe opening 9 at the bottom of the tank, and the bottom of pipeline No. 121 is connected with one end of pipeline No. 4 124 through pipeline No. 2 122 and pipeline No. 3 123 in sequence. The other end of pipeline No. 4 124 is connected with pipeline No. 5 125 and pipeline No. 6 126 respectively. An explosion relief pipe opening 10 is installed above pipeline No. 5 125, and pipeline No. 6 126 is connected with the overflow pipe opening 11 through pipeline No. 7 127, pipeline No. 8 128 and pipeline No. 9 129 in sequence. The first pipeline 121, the second pipeline 122, the third pipeline 123, and the fourth pipeline 124 are all connected by elbows, and the sixth pipeline 126, the seventh pipeline 127, the eighth pipeline 128, and the ninth pipeline 129 are all connected by elbows. The length of the eighth pipeline 128, that is, the height H1, is not less than 250 mm.

[0032] The explosion relief overflow pipe 12 is a pipe with specific shape requirements. Figure 2 It is made of pipes, pipe fittings and flanges, connected to the tank bottom pipe port 9 in the form of a flange, and installed with a detachable bracket 14 in the form of a bolt; the explosion-proof pipe port 10 and the overflow pipe port 11 are the ends of the explosion-proof overflow pipe 12 connected to the atmosphere, and can be adjusted according to the drainage volume and the explosion-proof gas volume; there is an upturned pipe in front of the overflow pipe port 11, namely the No. 8 pipeline 128, whose length is also the height H1, and the height difference H1 shall not be less than 250mm.

[0033] The length of the air inlet inner extension pipe 6 must meet the following length requirements: the height H2 from the tank bottom should be greater than the pipe diameter and should not be less than 100 mm.

[0034]

[0035] The size of the biogas inlet pipe 5 and the biogas outlet pipe 8 should be the same as the diameter of the external biogas pipe. The exhaust pipe 9 and the explosion relief overflow pipe 12 should not be smaller than the size of the water supply pipe 7. The explosion relief pipe 10 is used to connect the subsequent explosion relief pipe. The connected explosion relief pipe should ensure that the actual explosion relief point meets the requirements of relevant specifications such as GB50160. The overflow pipe 11 can be connected to the drainage collection facility to collect the discharged condensate for further treatment.

[0036] In a preferred embodiment of the present invention, an on-site magnetic flap level meter and an ultrasonic level meter or a radar level meter are used to replace the magnetic flap level meter with a remote transmission function.

[0037] In a preferred embodiment of the present invention, a maintenance manhole is added to the tank wall, and the removable top cover is replaced by a fixed top cover to replace the maintenance function of the removable top cover.

[0038] In a preferred embodiment of the present invention, the water seal tank can also be used in other occasions where liquid seal is formed by utilizing liquid static pressure.

[0039] The beneficial effect of the present invention is that the removable top cover can be used for equipment inspection and maintenance. The water in the water seal tank can be automatically discharged through the explosion relief overflow pipe, and the liquid level will not be higher than the set liquid level, so that the biogas generated by the anaerobic reactor can flow under the set water seal conditions. The excess water replenishment or condensed water brought in by the biogas is automatically discharged in the form of overflow, which can effectively avoid the risk of excessive reduction of the water seal liquid level or even loss of the water seal due to misoperation, and can also effectively reduce the workload of daily operation and maintenance. The gas in the water seal tank mainly enters the subsequent biogas collection and treatment pipelines and equipment through the biogas outlet, and can also be vented to the air through the explosion relief overflow pipe when the valve behind the water seal tank is misoperated, ensuring that the pressure in the biogas inlet pipe is maintained in a relatively stable range, ensuring that the biogas will not be excessively accumulated in the three-phase separator of the anaerobic reactor until a large amount of leakage is leaked to the waste gas treatment system, affecting the safe and stable operation of the waste gas treatment system. The air pressure in the water seal tank is maintained in a relatively stable range, and the maximum value is the pressure corresponding to the height difference from the overflow port of the explosion relief overflow pipe to the lowest point of its pipeline. Due to the pressure balance on both sides, this parameter is used to calculate the maximum buoyancy that the anaerobic three-phase separator can generate. Compared with the maximum buoyancy value of the three-phase separator of the previous anaerobic reactor, which is calculated based on the maximum buoyancy value when the biogas overflows from the bottom of the gas collecting chamber, the maximum buoyancy value will be effectively reduced after adopting the present invention, thereby effectively reducing the anti-floating engineering workload of the three-phase separator.

[0040] The principle of a new type of biogas system water seal tank:

[0041] The water in the water seal tank is connected through the water replenishment port, and the liquid level in the tank continues to rise until it overflows from the overflow port of the explosion relief overflow pipe, reaching the set liquid level and will not exceed the set liquid level. After the water replenishment is completed, the water replenishment soft connection pipe connected to the water replenishment port should be disconnected in time to ensure that toxic and harmful gases do not flow back into the water replenishment pipe. After the biogas enters from the biogas inlet pipe, it passes through the inner extension pipe and the water seal liquid surface. Because the pipe on the side of the explosion relief overflow pipe close to the water seal tank has the same liquid level as that in the tank, the biogas in the water seal tank will be discharged from the water seal tank from the outlet pipe first. The condensate and water vapor brought in by the biogas are partially trapped in the water seal tank and overflow through the explosion relief overflow pipe, so that the water volume in the tank remains unchanged and the liquid level is not higher than the set liquid level. When the biogas outlet cannot discharge biogas due to misoperation or other reasons, the air pressure in the water seal tank and the biogas inlet pipe rises, the liquid in the tank is discharged through the overflow pipe, the liquid level drops, and the liquid level in the pipe on the side of the explosion relief overflow pipe close to the tank body remains unchanged. The liquid level difference at both ends continues to increase. Once it exceeds the height difference between the overflow port and the lowest point of its pipeline, the biogas will be discharged from the explosion relief pipe port because there is still a 250mm water seal liquid level in front of the overflow pipe port. When the biogas pressure gradually increases, the remote level gauge will detect the signal of the lowered liquid level in the water seal tank, and the local pressure gauge will detect the signal of high pressure in the water seal tank, so that the operation and maintenance personnel can timely inspect and repair or evacuate personnel. The root valve of the local pressure gauge is to facilitate the operation and maintenance of the instrument. The removable top cover is to facilitate the inspection and maintenance work in the tank. The removable bracket and the bottom pipe port of the tank are to facilitate the inspection and maintenance of the overflow explosion relief pipe. The bottom pipe port of the tank can also be used to empty the tank body.

[0042] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A new type of biogas system water seal tank, characterized by: The invention comprises a water seal tank body (1), a detachable top cover (2), a lower connecting pipe opening (3) of a liquid level gauge, an upper connecting pipe opening (4) of a liquid level gauge, a biogas inlet pipe opening (5), an inlet inner extension pipe (6), a water supply pipe opening (7), a biogas outlet pipe opening (8), a tank bottom pipe opening (9), an explosion relief pipe opening (10), an overflow pipe opening (11), an explosion relief overflow pipe (12), an on-site pressure gauge (13) and a detachable bracket (14), wherein the upper connecting pipe opening (4) of the liquid level gauge and the lower connecting pipe opening (3) of the liquid level gauge are sequentially installed on one side of the water seal tank body (1) from top to bottom, the detachable top cover (2) is installed on the top of the water seal tank body (1), and the upper portion of the detachable top cover (2) is provided with a pressure gauge. A biogas inlet pipe (5), a water supply pipe (7), a biogas outlet pipe (8), an on-site pressure gauge (13) and an inlet inner extension pipe (6) are installed, and a detachable top cover (2) is connected to the water seal tank body (1), and the inlet inner extension pipe (6) is located in the water seal tank body (1), a tank bottom pipe opening (9) is installed at the bottom of the water seal tank body (1), one side of the tank bottom pipe opening (9) is connected to the explosion relief overflow pipe (12) pipeline, an explosion relief pipe opening (10) is installed above the explosion relief overflow pipe (12), an overflow pipe opening (11) is installed on one side below the explosion relief overflow pipe (12), and the explosion relief overflow pipe (12) is installed to one side of the water seal tank body (1) through a detachable bracket (14).

2. A novel biogas system water seal tank according to claim 1, characterized in that: The lower connecting pipe opening (3) of the liquid level gauge, the upper connecting pipe opening (4) of the liquid level gauge, the biogas inlet pipe opening (5), the inlet inner extension pipe (6), the biogas outlet pipe opening (8), the tank bottom pipe opening (9), and the detachable bracket (14) are all connected to the water seal tank body (1) or the detachable top cover (2) by welding; the explosion relief pipe opening (10) and the overflow pipe opening (11) are all connected to the explosion relief overflow pipe (12) by welding.

3. The novel biogas system water seal tank according to claim 1 is characterized by: The connection mode between the tank bottom pipe opening (9) and the explosion relief overflow pipe (12) is flange connection, and the connection mode between the local pressure gauge (13), the water supply pipe opening (7) and the detachable top cover (2) is flange connection.

4. A novel biogas system water seal tank according to claim 1, characterized in that: The water seal tank body (1) and the detachable top cover (2) are made of steel.

5. The novel biogas system water seal tank according to claim 1 is characterized by: The explosion relief overflow pipe (12) comprises a No. 1 pipeline (121), a No. 2 pipeline (122), a No. 3 pipeline (123), a No. 4 pipeline (124), a No. 5 pipeline (125), a No. 6 pipeline (126), a No. 7 pipeline (127), a No. 8 pipeline (128) and a No. 9 pipeline (129). The No. 1 pipeline (121) is connected to the tank bottom pipe opening (9) at the top, and the No. 1 pipeline (121) is connected to the No. 2 pipeline (122) at the bottom. The pipeline (122) and the third pipeline (123) are connected to one end of the fourth pipeline (124), and the other end of the fourth pipeline (124) is respectively connected to the fifth pipeline (125) and the sixth pipeline (126). An explosion relief pipe opening (10) is installed above the fifth pipeline (125), and the sixth pipeline (126) is connected to the overflow pipe opening (11) through the seventh pipeline (127), the eighth pipeline (128) and the ninth pipeline (129) in sequence.

6. A novel biogas system water seal tank according to claim 5, characterized in that: The No. 1 pipeline (121), the No. 2 pipeline (122), the No. 3 pipeline (123), and the No. 4 pipeline (124) are all connected by elbows, and the No. 6 pipeline (126), the No. 7 pipeline (127), the No. 8 pipeline (128), and the No. 9 pipeline (129) are all connected by elbows.

7. The novel biogas system water seal tank according to claim 5 is characterized by: The height H1 of the No. 8 pipeline (128) is not less than 250 mm.

8. The novel biogas system water seal tank according to claim 1 is characterized by: The length of the air intake inner extension pipe (6) must meet certain requirements, and the height H2 from the tank bottom should be greater than the diameter of the air intake inner extension pipe (6) and should not be less than 100 mm.

9. The novel biogas system water seal tank according to claim 1 is characterized by: The sizes of the biogas inlet pipe opening (5) and the biogas outlet pipe opening (8) should be equal to the diameter of the biogas pipe connected to the outside.

10. The novel biogas system water seal tank according to claim 1, characterized in that: The drain pipe opening (9) and the explosion relief overflow pipe (12) should not be smaller than the water supply pipe opening (7).

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