Side wall stirring type digestion tank

Abstract

The utility model relates to the technical field of digestion tanks, in particular to a side wall stirring type digestion tank which comprises a tank body, a sealing film, a circulating pump, a heat preservation layer, a guide cylinder, a stirring device and a heat tracing pipe. The stirring device comprises a first stirring device and a second stirring device, the second stirring device is installed in the guide cylinder, a shaft cylinder of the second stirring device is of a split type and comprises a first shaft cylinder and a second shaft cylinder, and the second shaft cylinder is connected with the guide cylinder through a fixing rod; the first stirring device and the second stirring device are symmetrically arranged on the two sides of the tank body in a 180-degree rotating mode, the included angle between the first stirring device and the tangent line of the tank body and the included angle between the second stirring device and the tangent line of the tank body are 30-60 degrees, and a heat tracing pipe is arranged on the inner side wall of the tank body. According to the utility model, the stable use of the equipment is ensured, and the distribution of materials and temperature in the digestion tank is more uniform through the first stirring device, the second stirring device and the heat tracing pipe, so that the stable and efficient proceeding of the digestion reaction is ensured.

Description

Technical Field

[0001] This utility model relates to the field of anaerobic digesters, specifically to a side-wall stirred digester. Background Technology

[0002] Currently, organic solid waste treatment processes include landfill, incineration, composting, and anaerobic digestion, among which anaerobic digestion is one of the mainstream technologies. Anaerobic digestion refers to the process by which organic matter is stabilized under anaerobic conditions through the metabolic activities of microorganisms, simultaneously producing methane and carbon dioxide. Anaerobic digestion is widely used both domestically and internationally, characterized by its mature technology, and the fact that both products and byproducts can be processed into marketable products, facilitating the formation of a circular economy chain.

[0003] Most existing anaerobic digestion devices use integrated anaerobic digesters. Organic matter enters from one side of the digester, remains for a period of time to complete degradation, and then the resulting digestate overflows from the other side. Due to the large volume of the digester, conventional stirring methods are insufficient to ensure thorough and uniform mixing of the materials within the tank, easily leading to sedimentation and resulting in poor degradation and reduced biogas production.

[0004] In view of this, existing digesters employ side-wall stirring, such as the "Large Anaerobic Fermentation Tank" disclosed in Chinese Utility Model Patent CN209307360U. By using side-wall stirring in conjunction with a circulating pump and a guide tube, the materials in the digester are circulated, thus ensuring thorough mixing. In addition, insulation is used to maintain the temperature in the tank, thereby playing a positive role in ensuring the digestion effect.

[0005] However, in long-term practice, it was found that when the stirring device is used in conjunction with the guide tube, the front end of the stirring device is prone to bending and deformation, which affects the stable use of the equipment. In addition, even with the above methods, it is difficult to distribute the material and temperature evenly in the tank, which has a certain impact on the digestion reaction. Therefore, we have carried out technical modifications to the digester and proposed a digester that can be used stably and can make the material and temperature distribution more uniform. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of the prior art by providing a side-wall stirred digester to improve the stability of the equipment and make the material and temperature distribution more uniform.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: a side-wall stirred digester, comprising a tank body, a sealing membrane, a circulating pump, an insulation layer, a guide tube, a first stirring device, and a second stirring device; the sealing membrane is located above the tank body and is sealed to the tank body; the circulating pump connects the bottom and top of the tank body; the first and second stirring devices are side-wall stirrers and are sealed to the tank body, with the second stirring device located inside the guide tube; both the first and second stirring devices include a stirring motor, a shaft cylinder, and an impeller; the drive shaft of the stirring motor is located inside the shaft cylinder, and the shaft cylinder is sealed to the tank body; the front end of the drive shaft is connected to the impeller; a shaft sealing device is provided between the drive shaft and the front end of the shaft cylinder; the shaft cylinder of the second stirring device includes a first shaft cylinder and a second shaft cylinder, the second shaft cylinder being located inside the tank body; the second shaft cylinder and the first shaft cylinder are detachably connected via a connecting flange; the shaft sealing device is provided between the drive shaft and the second shaft cylinder.

[0008] Furthermore, the guide tube includes a cylinder body and a liquid outlet. The cylinder body is fixedly connected to the tank body, the liquid outlet is located on one side of the cylinder body, the impeller of the second stirring device is located in the liquid outlet, and the second shaft is fixedly connected to the cylinder wall at the liquid outlet.

[0009] Furthermore, multiple fixing rods are evenly distributed between the second shaft cylinder and the cylinder wall at the liquid outlet.

[0010] Furthermore, a flange is provided on the shaft, the flange is located outside the tank and is fixedly connected to the tank, and the connection between the shaft and the inside of the tank is sealed with sealant.

[0011] Furthermore, the tank body is provided with a feed inlet, a discharge outlet, a slag discharge outlet, an air vent, and a biogas outlet. The feed inlet, discharge outlet, and slag discharge outlet are all located on the top of the tank body. The feed inlet and slag discharge outlet are located at the liquid level of the material in the tank body, the discharge outlet is located below the liquid level, the air vent is located at the bottom of the tank body, and the biogas outlet is located above the liquid level in the tank body and below the sealing membrane.

[0012] Furthermore, the tank body is provided with a first circulation port at the bottom and a second circulation port at the top. The first circulation port and the second circulation port are connected by a circulation pump. The material in the tank body flows from the first circulation port to the second circulation port. The second circulation port is located below the sealing membrane.

[0013] Furthermore, the first stirring device and the second stirring device are arranged symmetrically on both sides of the tank at a 180° rotational angle, and the included angle between the first stirring device and the second stirring device and the tangent of the tank is 30 to 60°.

[0014] Furthermore, a heat tracing pipe is arranged on the inner wall of the tank, and a water manifold is installed on the outside of the tank, which is connected to the heat tracing pipe.

[0015] The beneficial effects of this utility model are:

[0016] 1. This utility model modifies the structure of the second stirring device, making it more stable during use and easier to maintain. This helps reduce the labor intensity and cost of maintenance and plays a positive role in ensuring the stable use of the digester.

[0017] 2. The arrangement of the first and second stirring devices in this invention allows the material in the tank to rotate, which is more conducive to the mixing of the material in the tank and plays a positive role in ensuring the stable and efficient digestion reaction.

[0018] 3. This utility model, through the heat tracing pipe installed inside the tank, helps to maintain the temperature inside the tank, and in conjunction with the stirring device, makes the temperature distribution inside the tank more uniform, which helps to ensure the stable and efficient progress of the digestion reaction. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the main view of this utility model;

[0020] Figure 2 This is a utility model Figure 1 Top view of section AA;

[0021] Figure 3 This is a schematic diagram of the main sectional view of this utility model;

[0022] Figure 4 This is a utility model Figure 2 A magnified view of part B in the middle section;

[0023] Figure 5 This is a schematic diagram of the principle of the water distribution device of this utility model.

[0024] The names corresponding to each mark in the diagram:

[0025] 1. Tank body; 11. Inlet; 12. Outlet; 13. Slag discharge port; 14. Air vent; 15. Biogas outlet; 16. First circulation port; 17. Second circulation port; 18. Insulation layer; 2. Top cover; 3. Circulation pump; 4. First stirring device; 5. Second stirring device; 51. First shaft cylinder; 52. Second shaft cylinder; 521. Shaft sealing device; 53. Impeller; 54. Flange; 55. Connecting flange; 56. Fixing rod; 6. Guide tube; 61. Cylinder body; 62. Liquid outlet; 7. Heating device; 71. Water collector; 72. Heat tracing pipe; 8. Sealing membrane. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model are within the protection scope of the present utility model.

[0027] Embodiments of this utility model:

[0028] like Figure 1-5 As shown, in this embodiment, a tank body 1 is provided, and a top cover 2 is provided on the tank body 1; a sealing membrane 8 is provided on the upper part of the inside of the tank body 1, and the sealing membrane 8 is sealed to the tank body 1, dividing the inside of the digester tank body 1 into an upper part and a lower part; a top cap is provided on the top cover 2, and a vent is provided on the top cover 2 below the top cap, and the upper part is connected to the outside atmosphere through the vent; an inlet 11, an outlet 12, a slag discharge outlet 13, and a biogas outlet 1 are provided on the upper part of the lower part of the tank body 1. 5. The feed inlet 11 and the slag discharge outlet 13 are located at the liquid level in the tank body 1, the discharge outlet 12 is located below the liquid level in the tank body 1 and the slag discharge outlet 13 is located above the discharge outlet 12, and the biogas outlet 15 is located above the liquid level in the tank body 1; an vent 14 is provided at the bottom of the tank body 1, and a first circulation port 16 and a second circulation port 17 are provided on the tank body 1, and a circulation pump 3 is installed through the first circulation port 16 and the second circulation port 17. The circulation pump 3 lifts the material in the tank body 1 from the bottom of the tank body 1 to the top of the tank body 1.

[0029] An agitator is arranged at the bottom of the tank 1 about 1m above the ground. The agitator includes an agitator motor, a shaft cylinder, and an impeller 53. The drive shaft of the agitator motor is located inside the shaft cylinder. The shaft cylinder is connected to the tank 1 by a flange 54 and sealed with sealant. The flange 54 is located outside the tank 1 and is connected to the tank 1 by fastening bolts. The connection between the shaft cylinder and the inside of the tank 1 is sealed with sealant. The front end of the drive shaft is connected to the impeller 53. A shaft sealing device 521 is provided between the drive shaft and the shaft cylinder.

[0030] The stirring device includes a first stirring device 4 and a second stirring device 5, which are symmetrically arranged on both sides of the tank 1 by rotating 180°. The included angle between the shaft of the first stirring device 4 and the second stirring device 5 and the tank 1 is 30-60°. The second stirring device 5 is installed in the guide tube 6, which includes a cylinder 61 and a liquid outlet 62. The cylinder 61 is arranged vertically in the tank 1, and the liquid outlet 62 is located on one side of the cylinder 61. The impeller 53 of the second stirring device 5 is located in the liquid outlet 62. The shaft of the second stirring device 5 includes a first shaft 51 and a second shaft 52, which are fixedly connected by a connecting flange 55. A shaft seal device 521 is provided between the second shaft 52 and the drive shaft of the stirring motor. A fixing rod 56 is fixedly provided between the second shaft 52 and the liquid outlet 62 of the guide tube 6.

[0031] A heating device 7 is installed in the tank body 1. The heating device 7 includes a heat tracing pipe 72 installed on the inner wall of the tank body 1 and a water manifold 71 on the outside of the tank body 1. The heat tracing pipe 72 is connected to the water manifold 71. At the same time, a heat insulation layer 18 is installed in the tank wall of the tank body 1. The heat insulation layer 18 is made of glass wool.

[0032] The principle of this utility model is as follows:

[0033] In use, this invention utilizes a first stirring device 4, a second stirring device 5, a guide tube 6, and a circulating pump 3 to agitate the material in the tank 1, thereby facilitating uniform mixing of the material. During the process, the first stirring device 4 and the second stirring device 5 are arranged at a certain angle to the tank 1, which also allows the material to rotate in the tube 61, further promoting mass transfer, mixing, and heat transfer between the materials. This plays a positive and beneficial role in ensuring and improving the efficiency of anaerobic digestion.

[0034] Furthermore, in this invention, the material in the tank 1 is heated and kept warm by the heat tracing pipe 72, thereby ensuring that the digestion reaction is at a suitable temperature and facilitating the stable progress of the digestion reaction. Temperature control during the process requires the use of temperature probes, control valves on the heat tracing pipe 72, and flow meters, etc. The process is relatively simple, and its principle is easy for those skilled in the art to understand, so it will not be elaborated further. At the same time, if automated control is implemented, it can be combined with electric valves and on-site PLC.

[0035] In the actual operation of this utility model, the second stirring device 5 is located in the guide tube 6. Due to the special nature of the operating environment, the front end of the second stirring device 5 is prone to bending and deformation, which causes the impeller 53 to tilt and severely wear the front end of the shaft. After the shaft wears, the shaft strength decreases significantly and cannot effectively support the front end of the second stirring device 5 and the impeller 53 to run smoothly. In this process, it is necessary to disassemble the tank wall to replace the shaft, which is time-consuming and laborious. Therefore, in this utility model, the shaft of the second stirring device 5 is set as a first shaft 51 and a second shaft 52. The second shaft 52 is connected to the first shaft 51 through a connecting flange 55, which makes maintenance and replacement more convenient and reduces the cost of maintenance and replacement. By setting a fixing rod 56 for support between the second shaft 52 and the guide tube 6, the stability of use is further guaranteed.

[0036] This utility model relates to a shaft sealing device 521, which is an existing transmission shaft rotation sealing device. It is a mature technology that is easy for those skilled in the art to understand, so it will not be described in detail here.

Claims

1. A side-wall stirred digester, comprising a tank body (1), a sealing membrane (8), a circulating pump (3), an insulation layer (18), a guide tube (6), a first stirring device (4), and a second stirring device (5); the sealing membrane (8) is located above the tank body (1) and is sealed to the tank body (1); the circulating pump (3) connects the bottom and top of the tank body (1); the first stirring device (4) and the second stirring device (5) are side-wall stirrers and are sealed to the tank body (1), the second stirring device (5) is located inside the guide tube (6); characterized in that: The first stirring device (4) and the second stirring device (5) both include a stirring motor, a shaft cylinder and an impeller (53). The drive shaft of the stirring motor is located inside the shaft cylinder, and the shaft cylinder is sealed to the tank body (1). The front end of the drive shaft is connected to the impeller (53), and a shaft sealing device (521) is provided between the drive shaft and the front end of the shaft cylinder. The shaft cylinder of the second stirring device (5) includes a first shaft cylinder (51) and a second shaft cylinder (52). The second shaft cylinder (52) is located inside the tank body (1), and the second shaft cylinder (52) and the first shaft cylinder (51) are detachably connected by a connecting flange (55). The shaft sealing device (521) is provided between the drive shaft and the second shaft cylinder (52).

2. The side-wall stirred digester according to claim 1, characterized in that: The guide tube (6) includes a cylinder (61) and a liquid outlet (62). The cylinder (61) is fixedly connected to the tank (1). The liquid outlet (62) is located on one side of the cylinder (61). The impeller (53) of the second stirring device (5) is located in the liquid outlet (62). The second shaft cylinder (52) is fixedly connected to the cylinder wall at the liquid outlet (62).

3. A side-wall stirred digester according to claim 2, characterized in that: Multiple fixing rods (56) are evenly distributed between the second shaft cylinder (52) and the cylinder wall at the liquid outlet (62).

4. A side-wall stirred digester according to claim 1, characterized in that: The shaft is provided with a flange (54), which is located outside the tank body (1) and fixedly connected to the tank body (1). The connection between the shaft and the inside of the tank body (1) is sealed with sealant.

5. A side-wall stirred digester according to claim 1, characterized in that: The tank (1) is provided with a feed inlet (11), a discharge outlet (12), a slag discharge outlet (13), an air vent (14), and a biogas outlet (15). The feed inlet (11), the discharge outlet (12), and the slag discharge outlet (13) are all located above the tank (1). The feed inlet (11) and the slag discharge outlet (13) are located at the liquid level of the material in the tank (1). The discharge outlet (12) is located below the liquid level. The air vent (14) is located at the bottom of the tank (1). The biogas outlet (15) is located above the liquid level in the tank (1) and below the sealing membrane (8).

6. A side-wall stirred digester according to claim 1, characterized in that: The tank (1) is provided with a first circulation port (16) at the bottom and a second circulation port (17) at the top. The first circulation port (16) and the second circulation port (17) are connected by a circulation pump (3). The material in the tank (1) flows from the first circulation port (16) to the first circulation port (16). The second circulation port (17) is located below the sealing membrane (8).

7. A side-wall stirred digester according to claim 1, characterized in that: The first stirring device (4) and the second stirring device (5) are arranged symmetrically on both sides of the tank (1) at 180° rotation. The angle between the first stirring device (4) and the second stirring device (5) and the tangent of the tank (1) is 30~60°.

8. A side-wall stirred digester according to claim 1, characterized in that: A heat tracing pipe (72) is arranged on the inner wall of the tank (1), and a water manifold (71) is provided on the outside of the tank (1), which is connected to the heat tracing pipe (72).

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