Sludge anaerobic digestion device

Abstract

The present application relates to sludge treatment technical field, especially a kind of sludge anaerobic digestion device, including processing tower, electrolysis component, heating component and filler component, processing tower is equipped with high-temperature digestion cavity, mesophilic digestion cavity and electrolytic cavity from outside to inside in sequence, electrolytic cavity top end is equipped with feeding port, bottom end is communicated with high-temperature digestion cavity bottom end, high-temperature digestion cavity top end is communicated with mesophilic digestion cavity top end, and mesophilic digestion cavity bottom end is connected with liquid discharge port;Electrolysis component is located in electrolytic cavity, can electrolysis macromolecular organic matter in sludge into small molecule;Heating component is located in high-temperature digestion cavity, can discharge dissolved oxygen in sludge and balance pH value;Filler component is located in mesophilic digestion cavity, including metal net and biochar particle, through interspecific direct electron transfer and electron buffer to improve microbial degradation efficiency, device greatly shortens digestion residence time, improves methane production rate and COD removal amount, and cavity integrated design reduces floor space, saves heating energy consumption.

Description

Technical Field

[0001] This invention relates to the field of sludge treatment equipment, and more specifically to a sludge anaerobic digestion device. Background Technology

[0002] Anaerobic digestion of sludge refers to a digestion technology in which facultative and anaerobic bacteria decompose biodegradable organic matter in sludge into CH4, CO2, H2O and H2S under anaerobic conditions. It can remove 30% to 50% of the organic matter in sludge and stabilize it, making it the most economical sludge treatment method for large-scale wastewater treatment plants.

[0003] Anaerobic digestion technology requires suitable temperature and pH conditions. This technology has a fatal drawback: the reaction time is long, generally requiring several days to several weeks. Therefore, anaerobic digestion equipment consists of huge tanks, resulting in high investment costs and high operation and maintenance expenses. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a sludge anaerobic digestion device in order to overcome the shortcomings of the prior art.

[0005] The technical solution adopted by this invention to solve its technical problem is: a sludge anaerobic digestion device, comprising: The processing tower has a high-temperature digestion chamber, a medium-temperature digestion chamber, and an electrolysis chamber arranged sequentially from the outside to the inside. The top of the electrolysis chamber has a feed port, the bottom of the electrolysis chamber is connected to the bottom of the high-temperature digestion chamber, the top of the high-temperature digestion chamber is connected to the top of the medium-temperature digestion chamber, and the bottom of the medium-temperature digestion chamber is connected to a drain port. An electrolysis unit, located inside the electrolysis chamber, is used to electrolyze the sludge within the electrolysis chamber; The heating component is located in the high-temperature digestion chamber and is used to heat the sludge inside the high-temperature digestion chamber. The packing assembly includes multiple metal meshes spaced apart from top to bottom, all of which are located within the mesophilic digestion chamber. Biochar particles are disposed between two adjacent metal meshes, and the pore size of the metal meshes is smaller than the particle size of the biochar particles.

[0006] Furthermore, the processing tower is provided with an outer cylinder, and an inner cylinder is provided inside the outer cylinder. A bottom plate is provided between the bottom end of the outer cylinder and the bottom end of the inner cylinder. The inner ring wall of the inner cylinder forms an electrolytic cavity; The outer ring wall of the outer cylinder and the inner ring wall of the processing tower form a high-temperature digestion chamber; The inner wall of the outer cylinder, the outer wall of the inner cylinder, and the bottom plate together form a mesothermal digestion cavity.

[0007] Furthermore, the metal mesh is a stainless steel mesh, and the surface of the metal mesh is covered with a transition metal oxide layer.

[0008] Furthermore, the transition metal oxide layer is a lead oxide layer, a manganese oxide layer, or a titanium oxide layer.

[0009] Furthermore, the electrolysis assembly includes an outer electrode ring and an inner electrode post, the inner electrode post being coaxially disposed within the outer electrode ring, and an electrolysis channel being formed between the outer electrode ring and the inner electrode post.

[0010] Furthermore, the space above the electrolysis assembly within the electrolysis chamber is the upper space, and the space below the electrolysis assembly within the electrolysis chamber is the lower space. The upper space is connected to the lower space through an electrolysis channel.

[0011] Furthermore, the top of the high-temperature digestion chamber is provided with an exhaust port that communicates with the outside.

[0012] Furthermore, the heating component is located at the bottom of the high-temperature digestion chamber.

[0013] Furthermore, the bottom end of the processing tower is provided with a discharge chamber, which is located below the mesophilic digestion chamber. The discharge chamber is provided with a discharge port, and the discharge port is connected to the discharge chamber.

[0014] The beneficial effects of this invention are: 1. This invention utilizes an electrolysis unit in the electrolysis chamber to break down large organic molecules in sludge into smaller organic molecules. Then, in a high-temperature digestion chamber, a heating unit removes dissolved oxygen from the sludge and promotes protein hydrolysis to generate ammonia, thus balancing the sludge's pH value and preventing acidification from inhibiting microbial growth. The sludge then enters a mesophilic digestion chamber for efficient decomposition and digestion. This series process, employing a high-temperature followed by a mesophilic approach, significantly improves methane yield and enhances the removal of organic matter from the sludge compared to single-stage high-temperature or single-stage mesophilic anaerobic processes. 2. This invention combines biochar, which serves as a pseudocapacitive material, with a metal mesh, which serves as a conductive material, to solve the problem that the rate at which acid-producing bacteria produce electrons is higher than the rate at which methanogens consume electrons. The metal mesh can assist the two types of microorganisms in establishing a direct interspecies electron transfer process, accelerating electron transfer. The pseudocapacitive properties of biochar can buffer excess electrons produced by acid-producing bacteria through surface quinone groups and slowly release them to methanogens. At the same time, it maintains a suitable pH value in the reaction system, reduces the inhibition of methanogenesis by acid accumulation, and the stable operation of methanogenesis can maintain a low hydrogen partial pressure environment, relieve the inhibition of acid-producing bacteria metabolism by hydrogen, and accelerate the degradation of organic matter. 3. This invention utilizes the sludge in the high-temperature digestion chamber to continuously heat the sludge in the medium-temperature digestion chamber, while simultaneously cooling the high-temperature sludge and raising the temperature of the low-temperature sludge, thus saving energy consumption.

[0015] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a schematic diagram of a sludge anaerobic digestion device; Figure 2 This is a schematic diagram of a metal mesh; Figure 3 This is a three-dimensional schematic diagram of the electrolysis assembly; Figure 4 This is a longitudinal cross-sectional view of the electrolysis assembly; In the diagram: 1. Processing tower; 11. High-temperature digestion chamber; 111. Exhaust port; 12. Mesotemperature digestion chamber; 121. Liquid drain port; 13. Electrolysis chamber; 131. Feed port; 2. Electrolysis assembly; 21. Outer electrode ring; 22. Inner electrode post; 23. Plastic connector; 3. Heating components; 4. Packing assembly; 41. Metal mesh; 411. Mesh opening; 42. Biochar; 5. Outer cylinder; 6. Inner cylinder; 7. Bottom plate; 8. Discharge chamber; 81. Discharge port. Detailed Implementation

[0018] The invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention in a schematic manner. Therefore, they only show the components relevant to the invention. Orientations and references (e.g., up, down, left, right, etc.) are only used to aid in the description of the features in the drawings. Therefore, the following specific embodiments are not intended to be restrictive, and the scope of the claimed subject matter is defined solely by the appended claims and their equivalents.

[0019] like Figure 1 and Figure 2 As shown, a sludge anaerobic digestion device includes a treatment tower 1, an electrolysis assembly 2, a heating assembly 3, and a packing assembly 4. The treatment tower 1 has a high-temperature digestion chamber 11, a meso-temperature digestion chamber 12, and an electrolysis chamber 13 arranged coaxially from the outside to the inside. The top of the electrolysis chamber 13 has a feed port 131, the bottom of the electrolysis chamber 13 is connected to the bottom of the high-temperature digestion chamber 11, the top of the high-temperature digestion chamber 11 is connected to the top of the meso-temperature digestion chamber 12, and the bottom of the meso-temperature digestion chamber 12 is connected to a drain port 121. The treatment tower 1 integrates the three functional chambers, reducing manual operation and container footprint. Sludge enters the electrolysis chamber 13 from the feed port 131, then flows into the high-temperature digestion chamber 11 from the bottom of the electrolysis chamber 13, accumulates in the high-temperature digestion chamber 11, and flows into the meso-temperature digestion chamber 12 from the top. Electrolysis component 2 is disposed in electrolysis chamber 13 and is used to electrolyze the sludge in electrolysis chamber 13, electrolyzing the large molecules in the sludge into small molecules, which are then facilitated by microbial degradation. Heating component 3 is installed in the high-temperature digestion chamber 11 to heat the sludge in the high-temperature digestion chamber 11. After heating, the sludge releases oxygen and can also promote protein hydrolysis to generate ammonia to balance the pH value of the sludge and avoid the inhibition of microbial growth by acidification. The packing assembly 4 includes multiple metal meshes 41 spaced apart from top to bottom. All metal meshes 41 are located in the mesophilic digestion chamber 12. Biochar 42 particles are arranged between two adjacent metal meshes 41. The pore size of the metal mesh 41 is smaller than the particle size of the biochar 42 particles. The sludge is digested at low temperature under the action of the packing assembly 4, generating nitrogen gas, which is discharged from the exhaust port.

[0020] In some examples, the processing tower 1 is provided with an outer cylinder 5, and an inner cylinder 6 is provided inside the outer cylinder 5. A bottom plate 7 is provided between the bottom end of the outer cylinder 5 and the bottom end of the inner cylinder 6. The inner wall of the inner cylinder 6 forms an electrolysis chamber 13. The outer wall of the outer cylinder 5 and the inner wall of the processing tower 1 form a high-temperature digestion chamber 11. The inner wall of the outer cylinder 5, the outer wall of the inner cylinder 6, and the bottom plate 7 form a medium-temperature digestion chamber 12. By concentrating the electrolysis chamber 13, the high-temperature digestion chamber 11, and the medium-temperature digestion chamber 12 in the same processing tower, the equipment footprint is greatly reduced. Furthermore, the adjacent walls of the three chambers are in direct contact. The residual heat of the high-temperature digestion chamber 11 can preheat the sludge in the medium-temperature digestion chamber 12, while simultaneously cooling the high-temperature sludge, thus saving heating energy. The processing tower 1 is provided with a tower cover, and the processing tower 1 and the tower cover are fastened together by bolts. The inner cylinder 6 is connected to the tower cover by screws. The tower cover has a feeding hole in the center and symmetrical exhaust holes at both ends. The feeding hole and the feeding port 131, and the exhaust hole and the exhaust port 111 correspond one-to-one.

[0021] In some examples, the metal mesh 41 is a stainless steel mesh, the surface of which is covered with a transition metal oxide layer. The metal mesh 41 consists of two semi-circular C-shaped stainless steel plates with densely packed mesh holes 411. The circumferential edges are higher than the plate thickness and are connected to the outer cylinder 5 and inner cylinder 6 respectively by screws.

[0022] In some examples, the transition metal oxide layer is a lead oxide layer, a manganese oxide layer, or a titanium oxide layer. The transition metal oxide has good conductivity, which can further optimize the interspecies direct electron transfer efficiency between the metal mesh and biochar, and alleviate the electron supply and demand imbalance between acid-producing bacteria and methanogenic bacteria.

[0023] In some examples, such as Figure 3 and Figure 4 As shown, the electrolysis assembly 2 includes an outer electrode ring 21 and an inner electrode post 22. The inner electrode post 22 is coaxially disposed inside the outer electrode ring 21, forming an electrolysis channel between the outer electrode ring 21 and the inner electrode post 22. The radius difference between the outer electrode ring 21 and the inner electrode post 22 is greater than the radius of the inner electrode post 22. The outer electrode ring 21 is configured as an annular cylindrical structure, and the inner electrode post 22 is configured as a cylindrical structure. The outer electrode ring 21 and the inner electrode post 22 can be connected and fixed by two plastic connectors 23. The inner electrode post 22 is fitted into the inner ring of the plastic connector 23. The outer ring of the plastic connector 23 is fixed to the inner wall of the outer electrode ring 21 by bolts. The outer electrode ring 21 of the annular electrode is fixed to the inner cylinder 6 by bolts. Sludge falls into the inner cylinder 6 from the gap between the outer electrode ring 21 and the inner electrode post 22. The design that the radius difference between the outer electrode ring 21 and the inner electrode post 22 is greater than the radius of the inner electrode post 22 makes the electrolysis channel width reasonable, avoiding local electric field concentration or insufficient electrolysis.

[0024] In some examples, the space above the electrolysis component 2 within the electrolysis chamber 13 is the upper space, and the space below the electrolysis component 2 within the electrolysis chamber 13 is the lower space. The upper space is connected to the lower space through an electrolysis channel, and sludge falls from the upper space into the lower space through the electrolysis channel.

[0025] In some examples, the top of the high-temperature digestion chamber 11 is provided with an exhaust port 111 that communicates with the outside, and sludge enters the high-temperature digestion chamber 11 from the exhaust port 111.

[0026] In some examples, the heating component 3 is located at the bottom of the high-temperature digestion chamber 11, and the sludge flows into the high-temperature digestion chamber 11 from the bottom of the electrolysis chamber 13 and is heated when it flows through the radiation area of ​​the heating component 3.

[0027] In some examples, the bottom of the processing tower 1 is provided with a discharge chamber 8, which is located below the mesophilic digestion chamber 12. The discharge chamber 8 is provided with a discharge port 81, and the liquid discharge port 121 is connected to the discharge chamber 8. The liquid discharge port 121 of the mesophilic digestion chamber 12 is connected to the liquid discharge port 121 of the discharge chamber 8, and the connection is covered with a flexible tube.

[0028] The working principle and process of this invention are as follows: During operation, sludge enters from the top feed port 131 and undergoes electrolysis in the electrolysis chamber 13. Electrolysis can degrade large organic molecules into smaller molecules, facilitating subsequent microbial degradation. Subsequently, the sludge enters the high-temperature digestion chamber 11 and is heated to 50-55°C by the heating component 3. This stage is the high-temperature digestion process. After this stage, the sludge flows from the upper end of the high-temperature digestion chamber 11 into the mesophilic digestion chamber 12. The sludge in the high-temperature digestion chamber 11 and the sludge in the mesophilic digestion chamber 12 undergo heat exchange, and the temperature drops to about 35-38°C. At the same time, the newly entered sludge in the mesophilic digestion chamber 12 is also continuously heated. Under the action of the packing material in the mesophilic digestion chamber 11, methane is rapidly produced. The produced gas escapes from the top exhaust port 111, and the reacted sludge is discharged from the bottom drain port 121 for dehydration treatment. The digestion process is completed. The entire digestion process takes 24–48 hours, and the COD (Chemical Oxygen Demand) removal rate is 18–25 kg / m³. 3 / d.

[0029] The above description, based on the preferred embodiments of the present invention, provides inspiration. Those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification but must be determined according to the claims.

Claims

1. A sludge anaerobic digestion device, characterized in that: include: The processing tower (1) has a high-temperature digestion chamber (11), a medium-temperature digestion chamber (12) and an electrolysis chamber (13) arranged sequentially from the outside to the inside. The top of the electrolysis chamber (13) has a feed port (131), the bottom of the electrolysis chamber (13) is connected to the bottom of the high-temperature digestion chamber (11), the top of the high-temperature digestion chamber (11) is connected to the top of the medium-temperature digestion chamber (12), and the bottom of the medium-temperature digestion chamber (12) is connected to a drain port (121). An electrolysis assembly (2) is disposed in an electrolysis chamber (13) for electrolyzing the sludge in the electrolysis chamber (13); Heating component (3) is disposed in high-temperature digestion chamber (11) for heating sludge in high-temperature digestion chamber (11); And the packing assembly (4), including multiple metal meshes (41) arranged at intervals from top to bottom, all of which are located in the mesophilic digestion chamber (12), and biochar (42) particles are arranged between two adjacent metal meshes (41), and the pore size (411) of the metal meshes (41) is smaller than the particle size of the biochar (42). The processing tower (1) is provided with an outer cylinder (5), and an inner cylinder (6) is provided inside the outer cylinder (5). A bottom plate (7) is provided between the bottom end of the outer cylinder (5) and the bottom end of the inner cylinder (6). The inner ring wall of the inner cylinder (6) forms an electrolytic cavity (13). The outer wall of the outer cylinder (5) and the inner wall of the processing tower (1) form a high-temperature digestion chamber (11). The inner wall of the outer cylinder (5), the outer wall of the inner cylinder (6), and the bottom plate (7) form a mesothermal digestion cavity (12). The electrolysis assembly (2) includes an outer electrode ring (21) and an inner electrode post (22). The inner electrode post (22) is coaxially disposed inside the outer electrode ring (21), and an electrolysis channel is formed between the outer electrode ring (21) and the inner electrode post (22). The space above the electrolysis component (2) in the electrolysis chamber (13) is the upper space, and the space below the electrolysis component (2) in the electrolysis chamber (13) is the lower space. The upper space is connected to the lower space through the electrolysis channel.

2. The sludge anaerobic digestion device according to claim 1, characterized in that: The metal mesh (41) is a stainless steel mesh, and the surface of the metal mesh (41) is covered with a transition metal oxide layer.

3. The sludge anaerobic digestion device according to claim 2, characterized in that: The transition metal oxide layer is a lead oxide layer, a manganese oxide layer, or a titanium oxide layer.

4. The sludge anaerobic digestion device according to claim 1, characterized in that: The top of the high-temperature digestion chamber (11) is provided with an exhaust port (111) that communicates with the outside.

5. The sludge anaerobic digestion device according to claim 1, characterized in that: The heating component (3) is located at the bottom of the high-temperature digestion chamber (11).

6. The sludge anaerobic digestion device according to claim 1, characterized in that: The bottom end of the processing tower (1) is provided with a discharge chamber (8), which is located below the mesophilic digestion chamber (12). The discharge chamber (8) is provided with a discharge port (81), and the discharge port (121) is connected to the discharge chamber (8).

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