A sewage purification device

Abstract

This invention belongs to the technical field of blower air duct technology, and specifically relates to a wastewater purification device. The technical solution is as follows: A wastewater purification device includes a wastewater treatment tank, a wastewater collection pool at the bottom of the wastewater treatment tank, and a wastewater treatment vessel mounted on the upper side of the wastewater collection pool. The wastewater treatment vessel includes, from top to bottom, an ultrasonic flocculation unit, a multi-layer centrifugal separation unit, an electric field-assisted separation unit, a nanomaterial filtration unit, and an effluent collection unit. A pumping pipe connects the bottom of the wastewater collection pool to the ultrasonic flocculation unit. This invention provides a wastewater purification device that can fully purify the wastewater generated during the cleaning of the air purification unit in the air duct of an air blower, avoiding direct discharge that could impact water bodies, soil, and the surrounding ecological environment.

Description

Technical Field

[0001] This invention belongs to the field of blower air duct technology, and specifically relates to a wastewater purification device. Background Technology

[0002] Excessive dust content in the blower's intake air can adversely affect the air pump blades, primarily including:

[0003] 1) Accelerated wear: A large amount of dust will aggravate the friction and wear on the blade surface, shortening the blade's service life.

[0004] 2) Reduced efficiency: Dust accumulation on the blade surface will change the aerodynamic characteristics of the blade and reduce the working efficiency of the air pump.

[0005] 3) Disruption of balance: Uneven dust deposition on the blades may cause the rotor to lose balance and cause vibration.

[0006] 4) Corrosion: Some dust components may be corrosive and accelerate the degradation of blade materials.

[0007] 5) Blocked air ducts: In severe cases, it may cause blockage of air passages, affecting air circulation.

[0008] To address these issues, an air filtration system is needed to filter the air entering the blower. Furthermore, to prevent excessive dust buildup in the air filter and its effectiveness, it needs to be cleaned regularly. Currently, the treatment of polluted sludge generated during air filter cleaning is a significant environmental issue; untreated sludge discharge will directly impact water bodies, soil, and the surrounding ecosystem. Summary of the Invention

[0009] In order to solve the above-mentioned problems in the prior art, the purpose of the present invention is to provide a wastewater purification device that can fully purify the wastewater generated by cleaning the air purification unit of the air corridor of the air blower, so as to avoid direct discharge and affect the water body, soil and surrounding ecological environment.

[0010] The technical solution adopted in this invention is as follows:

[0011] A wastewater purification device includes a wastewater treatment tank, a wastewater collection pool at the bottom of the wastewater treatment tank, and a wastewater treatment vessel installed on the top of the wastewater collection pool. The wastewater treatment vessel includes, from top to bottom, an ultrasonic flocculation unit, a multi-layer centrifugal separation unit, an electric field-assisted separation unit, a nanomaterial filtration unit, and an effluent collection unit. A pumping pipe is connected between the bottom of the wastewater collection pool and the ultrasonic flocculation unit.

[0012] The wastewater collection tank of this invention collects wastewater, which is then sent to an ultrasonic flocculation unit. Microbubbles generated by ultrasonic cavitation promote the collision and aggregation of small particles in the wastewater, forming larger flocs that facilitate subsequent separation. A multi-layer centrifugal separation unit separates the sludge from the wastewater, and the separated sludge is then discharged. The wastewater is further treated by an electric field-assisted separation unit and a nanomaterial filtration unit before being sent to an effluent collection unit. The ultrasonic flocculation unit, multi-layer centrifugal separation unit, electric field-assisted separation unit, and nanomaterial filtration unit of this invention can fully treat wastewater, preventing the discharged water from impacting water bodies, soil, and the surrounding ecological environment.

[0013] In a preferred embodiment of the present invention, the bottom of the sewage collection tank is provided with several sewage sump pits, and a pumping device is installed in each sewage sump pit. A pumping pipe is connected to the pumping device, and a large-aperture filter screen is installed on the upper part of the sewage sump pit. Sewage flows from the sewage collection tank into each sewage sump pit, facilitating the pumping device in the sewage sump pit to pump the sewage to the ultrasonic flocculation unit. The large-aperture filter screen can block large impurities, preventing them from entering the sewage treatment tank.

[0014] In a preferred embodiment of the present invention, the ultrasonic flocculation unit is equipped with a stirring device and an ultrasonic generator. A effluent weir is located at the top of the ultrasonic flocculation unit, and an effluent pipe is connected to the bottom of the weir. The lower end of the effluent pipe is connected to a multi-layer centrifugal separation unit. Under the thorough stirring action of the stirring device, the ultrasonic generator utilizes the ultrasonic cavitation effect to generate microbubbles, promoting the collision and aggregation of small particles in the wastewater, forming larger flocs that facilitate subsequent separation. The ultrasonically treated water flows into the multi-layer centrifugal separation unit through the effluent weir and effluent pipe, preventing lower-layer wastewater from entering the multi-layer centrifugal separation unit.

[0015] As a preferred embodiment of the present invention, the multi-layer centrifugal separation unit is provided with several large-pore ceramic foam filter chambers, and a pressurized filtration device is provided in the large-pore ceramic foam filter chambers. The top of the pressurized filtration device is connected to the ultrasonic flocculation unit through a water outlet pipe. A floc recovery spiral is installed in the pressurized filtration device. A drainage weir is provided at the top of the multi-layer centrifugal separation unit, and a drainage pipe is connected between the drainage weir and the electric field-assisted separation unit.

[0016] The effluent pipe between the multi-layer centrifugal separation unit and the ultrasonic flocculation unit is equipped with a pressurization device, meaning the influent is under pressure. The floc recovery device rotates continuously, collecting and compressing the flocs. The pressurized filter is internally sealed and connected to a sludge discharge pipe, allowing for venting during sludge discharge. The pressurized filter itself is made of a large-pore rigid support material, with an inner wall of 1–10 μm ceramic membrane material, achieving mechanical filtration. The large-pore ceramic foam filter chamber further removes particulate pollutants through adsorption. The treated wastewater is then sent to the electric field-assisted separation unit via a drainage weir and drainage pipe.

[0017] In a preferred embodiment of the present invention, a sludge collection device is provided at the bottom of the sewage collection tank. The sludge collection device is connected to a sludge discharge pipe, which is connected to the bottom of several pressurized filtration devices. The pressurized filtration devices are internally sealed and connected to a sludge discharge pipe, allowing them to vent during sludge discharge. The sludge is then fed into the sludge collection device through the sludge discharge pipe.

[0018] In a preferred embodiment of the present invention, the electric field-assisted separation unit includes multiple layers of electrode separation plates with progressively decreasing heights arranged from the outside to the inside. A drain pipe is connected to the innermost electrode separation plate, and the other end of the drain pipe is connected to a multi-layer centrifugal separation unit. An outlet is provided in the innermost electrode separation plate, and the outlet is connected to a nanomaterial filtration unit. Wastewater flows sequentially from the outer electrode separation plate into the inner electrode separation plate, removing charged particles, colloids, etc.

[0019] As a preferred embodiment of the present invention, an annular water distribution pipe is provided inside the outermost electrode separation plate, and the annular water distribution pipe is connected to the inlet pipe. The annular water distribution pipe enables sewage to be evenly fed into the outermost electrode separation plate from all directions.

[0020] In a preferred embodiment of the present invention, the nanomaterial filtration unit comprises several layers of nanomaterial filtration membranes arranged sequentially from the outside to the inside. The innermost nanomaterial filtration membrane has its inner cavity connected to an electric field-assisted separation unit via a water outlet. A water collection pipe is connected to the innermost nanomaterial filtration membrane, and the other end of the water collection pipe is connected to an outlet collection unit. Wastewater flows sequentially from the innermost nanomaterial filtration membrane to the outermost nanomaterial filtration membrane, thereby achieving thorough filtration of the wastewater.

[0021] In a preferred embodiment of the present invention, an ultraviolet lamp is disposed on the inner wall of the nanomaterial filter membrane. The ultraviolet light enables a surface-enhanced advanced oxidation reaction, further removing recalcitrant organic matter from the wastewater.

[0022] In a preferred embodiment of the present invention, the nanomaterial filter membrane is provided with annular nano-microbubble channels. The nano-microbubble channels allow nano-microbubbles to pass through the spaces between the nanomaterial filter membranes, effectively removing recalcitrant organic substances in conjunction with ultraviolet light.

[0023] The beneficial effects of this invention are as follows:

[0024] The wastewater collection tank of this invention collects wastewater, which is then sent to an ultrasonic flocculation unit. Microbubbles generated by ultrasonic cavitation promote the collision and aggregation of small particles in the wastewater, forming larger flocs that facilitate subsequent separation. A multi-layer centrifugal separation unit separates the sludge from the wastewater, and the separated sludge is then discharged. The wastewater is further treated by an electric field-assisted separation unit and a nanomaterial filtration unit before being sent to an effluent collection unit. The ultrasonic flocculation unit, multi-layer centrifugal separation unit, electric field-assisted separation unit, and nanomaterial filtration unit of this invention can fully treat wastewater, preventing the discharged water from impacting water bodies, soil, and the surrounding ecological environment. Attached Figure Description

[0025] Figure 1 This is a cross-sectional view of the first position of the present invention;

[0026] Figure 2 This is a cross-sectional view of the second position of the present invention;

[0027] Figure 3 This is a structural schematic diagram of a wastewater treatment tank;

[0028] Figure 4 This is a partial structural diagram of the present invention;

[0029] Figure 5 This is a schematic diagram of the ultrasonic flocculation unit;

[0030] Figure 6 This is a schematic diagram of the structure of a multi-layer centrifugal separation unit;

[0031] Figure 7 This is a partial structural diagram of the electric field-assisted separation unit;

[0032] Figure 8 This is a schematic diagram of the structure of a nanomaterial filtration unit.

[0033] In the diagram: 1-Wastewater treatment tank; 2-Wastewater collection tank; 3-Wastewater treatment vessel; 4-Ultrasonic flocculation unit; 5-Multi-layer centrifugal separation unit; 6-Electric field assisted separation unit; 7-Nanomaterial filtration unit; 8-Effluent collection unit; 21-Pumping pipe; 22-Wastewater sump; 23-Pumping device; 24-Large-pore filter screen; 25-Sludge collection device; 26-Sludge discharge pipe; 41-Stirring device; 42-Ultrasonic generator; 43-Effluent weir; 44-Effluent pipe; 51-Large-pore ceramic foam filter chamber; 52-Pressurized filtration device; 53-Flocculant recovery spiral; 54-Drainage weir; 55-Drainage pipe; 61-Electrode separation plate; 62-Outlet; 63-Annular water distribution pipe; 71-Nanomaterial filter membrane; 72-Collection pipe; 73-Ultraviolet lamp tube; 74-Nanomicrobubble pipeline. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0035] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention. It should be noted that, unless otherwise specified, the embodiments and features described in the embodiments of the invention can be combined with each other.

[0036] like Figures 1-3 As shown, a wastewater purification device in this embodiment includes a wastewater treatment tank 1, a wastewater collection tank 2 at the lower part of the wastewater treatment tank 1, and a wastewater treatment vessel 3 installed on the upper side of the wastewater collection tank 2. The wastewater treatment vessel 3 includes, from top to bottom, an ultrasonic flocculation unit 4, a multi-layer centrifugal separation unit 5, an electric field-assisted separation unit 6, a nanomaterial filtration unit 7, and an effluent collection unit 8. A pumping pipe 21 is connected between the bottom of the wastewater collection tank 2 and the ultrasonic flocculation unit 4.

[0037] After collecting sewage in the sewage collection tank 2 of this invention, the sewage is sent to the ultrasonic flocculation unit 4. Microbubbles generated by the ultrasonic cavitation effect promote the collision and aggregation of small particles in the sewage, forming larger flocs that facilitate subsequent separation. The multi-layer centrifugal separation unit 5 centrifuges the sludge in the sewage, and the separated sludge is discharged. The sewage is then fully treated by the electric field-assisted separation unit 6 and the nanomaterial filtration unit 7 before being sent to the effluent collection unit 8. The ultrasonic flocculation unit 4, multi-layer centrifugal separation unit 5, electric field-assisted separation unit 6, and nanomaterial filtration unit 7 of this invention can fully treat sewage, preventing the discharged water from affecting water bodies, soil, and the surrounding ecological environment.

[0038] Furthermore, the bottom of the sewage collection tank 2 is provided with several sewage sump pits 22, and a pumping device 23 is installed in each sewage sump pit 22. A pumping pipe 21 is connected to the pumping device 23, and a large-aperture filter screen 24 is installed on the upper part of the sewage sump pit 22. Sewage flows from the sewage collection tank 2 into each sewage sump pit 22, facilitating the pumping device 23 in the sewage sump pit 22 to pump the sewage to the ultrasonic flocculation unit 4. The large-aperture filter screen 24 can block large impurities, preventing them from entering the sewage treatment tank 3.

[0039] Specifically, such as Figure 4 and Figure 5 As shown, the ultrasonic flocculation unit 4 is equipped with a stirring device 41 and an ultrasonic generator 42. A water outlet weir 43 is located at the top of the ultrasonic flocculation unit 4, and a water outlet pipe 44 is connected to the bottom of the weir 43. The lower end of the water outlet pipe 44 is connected to the multi-layer centrifugal separation unit 5. Under the full stirring action of the stirring device 41, the ultrasonic generator 42 utilizes the ultrasonic cavitation effect to generate microbubbles, promoting the collision and aggregation of small particles in the wastewater, forming larger flocs, which facilitate subsequent separation. The ultrasonically treated water flows into the multi-layer centrifugal separation unit 5 through the water outlet weir 43 and the water outlet pipe 44, preventing lower-layer wastewater from entering the multi-layer centrifugal separation unit 5.

[0040] Key parameters of the ultrasonic generator 42: Frequency range: 20–40 kHz; Power density: 0.1–0.5 W / cm² 3 Processing time: 30–120 s. Performance data: Average floc size increase: 200%–300%; Turbidity reduction: 60%–80%; Energy consumption: 0.05–0.1 kWh / m³ 3 .

[0041] Multi-band combination: Simultaneous use of ultrasonic waves at different frequencies improves flocculation efficiency. Pulse mode: Intermittent ultrasonic treatment reduces energy consumption. Adaptive control: Ultrasonic parameters are adjusted in real time according to the influent water quality.

[0042] Specifically, such as Figure 6 As shown, the multi-layer centrifugal separation unit 5 is provided with several large-pore ceramic foam filter chambers 51. The large-pore ceramic foam filter chambers 51 are provided with pressurized filter devices 52. The top of the pressurized filter device 52 is connected to the ultrasonic flocculation unit 4 through a water outlet pipe 44. The pressurized filter device 52 is equipped with a floc recovery spiral 53. The top of the multi-layer centrifugal separation unit 5 is provided with a drainage weir 54. The drainage weir 54 is connected to the electric field-assisted separation unit 6 by a drainage pipe 55.

[0043] The outlet pipe 44 between the multi-layer centrifugal separation unit 5 and the ultrasonic flocculation unit 4 is equipped with a pressurization device, meaning the inlet water is under pressure. The floc recovery device rotates continuously, collecting and rotating the flocs for compression. The pressurized filter device 52 is internally sealed and connected to a sludge discharge pipe, allowing for venting during sludge discharge. The pressurized filter device 52 itself is made of a large-pore rigid support material, with an inner wall of 1–10 μm ceramic membrane material, achieving mechanical filtration. The large-pore ceramic foam filter chamber 51 further removes particulate pollutants through adsorption. The treated wastewater is sent to the electric field-assisted separation unit 6 via a drainage weir 54 and a drainage pipe 55.

[0044] Furthermore, a sludge collection device 25 is installed at the bottom of the sewage collection tank. The sludge collection device 25 is connected to a sludge discharge pipe 26, which is connected to the bottom of several pressurized filter devices 52. The pressurized filter devices 52 are internally sealed and connected to the sludge discharge pipe, allowing them to vent during sludge discharge. The sludge is fed into the sludge collection device 25 through the sludge discharge pipe 26, which is controlled by an electric valve.

[0045] Specifically, such as Figure 7 As shown, the electric field-assisted separation unit 6 includes multi-layer electrode separation plates 61 with progressively decreasing heights arranged from the outside to the inside. A drain pipe 55 is connected inside the outermost electrode separation plate 61, and the other end of the drain pipe 55 is connected to the multi-layer centrifugal separation unit 5. An outlet 62 is provided inside the innermost electrode separation plate 61, and the outlet 62 is connected to the nanomaterial filtration unit 7. Wastewater flows sequentially from the outermost electrode separation plate 61 into the innermost electrode separation plate 61, removing charged particles, colloids, etc. An annular water distribution pipe 63 is provided inside the outermost electrode separation plate 61, and the annular water distribution pipe 63 is connected to the inlet pipe. The annular water distribution pipe 63 allows wastewater to be evenly fed into the outermost electrode separation plate 61 from all directions.

[0046] Technical parameters: Electric field strength: 0.5-2kV / cm; Electrode material: Titanium-based DSA (size-stabilized anode) electrode; Electrode spacing: 5-10cm; Power supply type: High-frequency pulsed DC power supply.

[0047] Performance data: Charged particle removal rate: >95%; Colloid removal rate: 80%–90%; Energy consumption: 0.1–0.3 kWh / m³ 3 water.

[0048] Features: Adaptive electric field strength adjustment: Automatically adjusts the electric field strength according to the conductivity of the influent; Multi-electrode design: Increases the electric field coverage area and improves separation efficiency; Electrochemical oxidation synergy: Simultaneously degrades some organic matter during the separation process.

[0049] Specifically, such as Figure 8 As shown, the nanomaterial filtration unit 7 includes several layers of nanomaterial filter membranes 71 arranged sequentially from the outside to the inside. The innermost nanomaterial filter membrane 71 is connected to the electric field-assisted separation unit 6 through a water outlet 62. A water collection pipe 72 is connected inside the outermost nanomaterial filter membrane 71, and the other end of the water collection pipe 72 is connected to the effluent collection unit 8. Wastewater flows sequentially from the innermost nanomaterial filter membrane 71 to the outermost nanomaterial filter membrane 71, thereby fully filtering the wastewater.

[0050] Material composition:

[0051] Base material: PVDF (polyvinylidene fluoride) membrane; Functionalized nanomaterials: graphene oxide (GO) and carbon nanotubes (CNTs). Nanomaterial loading: 0.1–0.5 wt%.

[0052] Composite structure design:

[0053] 1) Adopting a multi-layer composite structure: PVDF is used as the functional layer, combined with a support layer with high mechanical strength. Support layer material selection: polysulfone (PSf), polyethersulfone (PES) or polyamide (PA).

[0054] Structural parameters: PVDF functional layer thickness: 0.1~0.5μm; support layer thickness: 50~150μm; total thickness: 50~200μm.

[0055] 2) Nanofiber reinforcement: High-strength nanofibers are added to the PVDF matrix; material selection: carbon nanotubes (CNTs), polyamide nanofibers; addition ratio: 0.5–2 wt%. Tensile strength is increased by 30%–50%, and Young's modulus is increased by 20%–40%.

[0056] 3) Crosslinking treatment: Crosslinking agent: diisocyanate, polyol; degree of crosslinking: 10% to 30%; the mechanical strength of the membrane is increased by 40% to 60%, and the solvent resistance is enhanced.

[0057] Loading method:

[0058] 1) In-situ polymerization method: Nanomaterials are directly added during the polymerization of PVDF monomers, with a loading of 1-5 wt%.

[0059] 2) Blend spinning method: Nanomaterials are mixed with PVDF solution and then spun, with a loading of 0.1-1 wt%.

[0060] 3) Surface modification method: Plasma-activated PVDF surface, nanomaterials applied by impregnation or spraying, and nanomaterials fixed by UV light or heat treatment, with a loading density of 0.1–0.5 mg / cm³. 2 .

[0061] Structural parameters: Tensile strength: >5 MPa; Elongation at break: >50%; Porosity: 60%–80%; Compressive strength: >0.5 MPa.

[0062] Filtration performance: Molecular weight cutoff: 100–1000 Da; Flux rate: 50–100 L / (m³) 2 • h)@0.1 MPa; Antifouling resistance: 90% flux recovery (after chemical cleaning)

[0063] Service life: Continuous operation time: >1000 hours; Chemical cleaning cycle: every 200-300 hours.

[0064] An ultraviolet lamp 73 is installed on the inner wall of the nanomaterial filter membrane 71. The ultraviolet light enables a surface-enhanced advanced oxidation reaction, further removing recalcitrant organic matter from the wastewater. A ring-shaped nano-microbubble channel 74 is installed inside the nanomaterial filter membrane 71. Nano-microbubbles pass through the nanomaterial filter membrane 71 into the space between the nanomaterial filter membranes via the nano-microbubble channel 74, effectively removing recalcitrant organic matter in conjunction with the ultraviolet light.

[0065] This invention is not limited to the above-described optional embodiments. Anyone can derive other various forms of products under the guidance of this invention. However, regardless of any changes made in their shape or structure, any technical solution that falls within the scope of the claims of this invention shall be protected by this invention.

Claims

1. A wastewater purification device, characterized in that: The system includes a sewage treatment tank (1), a sewage collection tank (2) at the bottom of the sewage treatment tank (1), a sewage treatment vessel (3) installed on the upper side of the sewage collection tank (2), and the sewage treatment vessel (3) includes an ultrasonic flocculation unit (4), a multi-layer centrifugal separation unit (5), an electric field-assisted separation unit (6), a nanomaterial filtration unit (7), and an effluent collection unit (8) arranged sequentially from top to bottom. A pumping pipe (21) is connected between the bottom of the sewage collection tank (2) and the ultrasonic flocculation unit (4). The multi-layer centrifugal separation unit (5) is provided with several large-pore ceramic foam filter chambers (51), and a pressurized filter device (52) is provided in the large-pore ceramic foam filter chamber (51). The top of the pressurized filter device (52) is connected to the ultrasonic flocculation unit (4) through the water outlet pipe (44). A floc recovery spiral (53) is installed in the pressurized filter device (52). A drainage weir (54) is provided at the top of the multi-layer centrifugal separation unit (5). A drainage pipe (55) is connected between the drainage weir (54) and the electric field assisted separation unit (6). The electric field-assisted separation unit (6) includes a multi-layer electrode separation plate (61) with decreasing height arranged sequentially from the outside to the inside. A drain pipe (55) is connected inside the outermost electrode separation plate (61), and the other end of the drain pipe (55) is connected to the multi-layer centrifugal separation unit (5). An outlet (62) is provided inside the innermost electrode separation plate (61), and the outlet (62) is connected to the nanomaterial filtration unit (7). The nanomaterial filtration unit (7) includes several layers of nanomaterial filtration membranes (71) arranged sequentially from the outside to the inside. The innermost layer of the nanomaterial filtration membrane (71) is connected to the electric field-assisted separation unit (6) through the water outlet (62). The outermost layer of the nanomaterial filtration membrane (71) is connected to a water collection pipe (72), and the other end of the water collection pipe (72) is connected to the water collection unit (8). An ultraviolet lamp tube (73) is arranged on the inner wall of the nanomaterial filtration membrane (71). A ring-shaped nano-microbubble channel (74) is arranged inside the nanomaterial filtration membrane (71).

2. The wastewater purification device according to claim 1, characterized in that: The bottom of the sewage collection tank (2) is provided with several sewage sump pits (22), and a pumping device (23) is installed in the sewage sump pit (22). The pumping pipe (21) is connected to the pumping device (23), and a large-diameter filter screen (24) is provided on the upper part of the sewage sump pit (22).

3. The wastewater purification device according to claim 1, characterized in that: The ultrasonic flocculation unit (4) is equipped with a stirring device (41) and an ultrasonic generator (42). The top of the ultrasonic flocculation unit (4) is provided with a water outlet weir (43), and the bottom of the water outlet weir (43) is connected to a water outlet pipe (44). The lower end of the water outlet pipe (44) is connected to the multi-layer centrifugal separation unit (5).

4. The wastewater purification device according to claim 1, characterized in that: It is also equipped with a sludge collection device (25), which is connected to a sludge discharge pipe (26), and the sludge discharge pipe (26) is connected to the bottom of several pressurized filter devices (52).

5. A wastewater purification device according to claim 1, characterized in that: An annular water distribution pipe (63) is provided inside the outermost electrode separation plate (61), and the annular water distribution pipe (63) is connected to the water inlet pipe.

Images