Multi-chamber groove type electrochemical oxidation reactor

Abstract

The invention relates to the technical field of industrial wastewater treatment, and discloses a multi-chamber groove type electrochemical oxidation reactor which comprises a closed long and narrow groove body, an electrode assembly and a plurality of flow guide partition plates. A water inlet is formed in the bottom of one end of the tank body in the length direction, and a water outlet is formed in the top of the other end, so that a bottom-in and top-out plug-flow type runner is formed, water flow short circuit, dead zone and short flow are effectively avoided, and the effective contact time of wastewater and electrodes is prolonged. The flow guide partition plates are of an arch structure, occupy half space of the section of the tank body in the vertical direction and are staggered up and down to divide an inner cavity of the tank body into a plurality of reaction chambers connected in series, the structural strength of the partition plates is enhanced, and the flow field uniformity of the tank body is optimized. And the electrode assembly spans the tank body and is in clearance fit with the baffle plates, so that the uniformity of flow channels around the electrode is ensured, and the current density deviation is avoided.

Description

Technical Field

[0001] This invention relates to the field of industrial wastewater treatment technology, specifically to a multi-chamber type trough-type electrochemical oxidation reactor. Background Technology

[0002] During the production processes of nuclear power plants and thermal power plants, industrial wastewater containing ammonia nitrogen is continuously generated. This type of wastewater has a high salt content and fluctuates greatly in chloride ion concentration. Direct discharge would cause serious pollution to the ecological environment, so it must be treated with high efficiency to meet discharge standards. Electrochemical oxidation has become one of the mainstream technologies for ammonia nitrogen wastewater treatment in the power industry due to its advantages such as high treatment efficiency, no secondary pollution, and suitability for high-salinity wastewater. Its core equipment is the electrochemical reactor, and the structural design of the reactor directly determines the ammonia nitrogen treatment efficiency, equipment operation stability, and engineering adaptability.

[0003] Currently, existing electrochemical reactors used for ammonia nitrogen wastewater treatment in the power industry have many technical defects, making it difficult to meet the actual engineering needs of nuclear power plants and thermal power plants: First, they have poor water quality adaptability. Given the fluctuating chloride ion concentration in power plant wastewater, existing reactors cannot achieve stable treatment. Treatment efficiency drops significantly when chloride ion concentration is too low, and harmful side reactions easily occur when concentration is too high. Second, the equipment structure is complex and operational reliability is low. Electrode arrangements are mostly segmented, with numerous electrical connection nodes, making them prone to poor contact and frequent malfunctions, failing to meet the long-term continuous and stable operation and low maintenance requirements of nuclear power plants. Third, the equipment is bulky and installation is cumbersome. It often adopts a decentralized layout or on-site construction of tanks, requiring a large number of auxiliary equipment, occupying a large area, and cannot be prefabricated in the factory or quickly hoisted on-site, contradicting the space-constrained and rapid deployment requirements of power plant condensate polishing workshops. Fourth, the high-load treatment capacity is insufficient. Existing reactors have low unit volume treatment flow rates and long hydraulic retention times. A single unit cannot meet the treatment needs of large-flow ammonia nitrogen wastewater from power plants, requiring multiple units to be arranged in parallel, further increasing equipment investment and floor space. Summary of the Invention

[0004] The present invention aims to provide a multi-chamber trough-type electrochemical oxidation reactor to solve the problems of existing ammonia nitrogen wastewater treatment equipment in the power industry, such as complex structure, poor reliability, difficulty in achieving high-load continuous operation, and incompatibility with compact installation in power plants.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a multi-chamber trough-type electrochemical oxidation reactor, comprising a sealed trough, electrode assemblies, and several flow guide baffles; the trough is a long and narrow trough, with an inlet at the bottom of one end along its length and an outlet at the top of the other end, forming a bottom-in, top-out push-flow channel; the flow guide baffles are vertically arranged in the inner cavity of the trough along its length, the baffles are arched and occupy half of the cross-section of the trough in the vertical direction, and several flow guide baffles are arranged alternately in the upper and lower parts, dividing the inner cavity of the trough into multiple reaction chambers connected in series; the several flow guide baffles form a reaction passage for the electrode assemblies to pass through, the electrode assemblies are straddling the trough in the left and right direction, the cross-sectional shape of the reaction passage is the same as the cross-sectional shape of the electrode assemblies, and the electrode assemblies are fitted with the flow guide baffles with a clearance.

[0006] The beneficial effects of this solution are as follows: This invention, through a narrow, enclosed tank with a bottom-inlet and top-outlet structure, forms a bottom-inlet, top-outlet push-flow channel, allowing wastewater to flow orderly along a fixed path. This effectively avoids short-circuiting, dead zones, and short-flow phenomena, extending the effective contact time between wastewater and electrodes, and significantly improving the oxidation removal efficiency of pollutants such as ammonia nitrogen. The flow guide baffles are vertically arranged along the length of the tank, employing an arched structure and occupying half of the tank's cross-section vertically. Their staggered arrangement divides the tank's internal cavity into multiple series reaction chambers, ensuring the water flows progressively and reacts fully. The arched structure also enhances the baffles' structural strength, resisting water flow impact and deformation. Simultaneously, the optimized channel morphology reduces flow resistance and improves the uniformity of the overall flow field within the tank. Several flow-guiding baffles together form a reaction path consistent with the cross-sectional shape of the electrode assembly. The electrode assembly is positioned horizontally within the tank and fits snugly with the flow-guiding baffles. This ensures stable installation of the electrode assembly and uniform flow distribution around the electrode, avoiding current density deviations caused by uneven local flow velocities. This guarantees the uniformity and stability of the electrochemical oxidation reaction, significantly improving wastewater treatment efficiency. The overall structure is compact, installation and maintenance are convenient, and no complex auxiliary equipment is required. It is suitable for continuous treatment of high-concentration ammonia nitrogen wastewater, effectively solving the technical problems of uneven flow field, insufficient contact time between wastewater and electrodes, and low treatment efficiency in traditional electrochemical oxidation reactors. It possesses good practicality and promotional value.

[0007] Preferably, as an improvement, end caps are installed at both ends of the tank along its length, and the electrode assembly is installed in the tank through the end caps at both ends.

[0008] Preferably, as an improvement, the electrode assembly includes several sets of electrode stacks, each set including several equally spaced electrode plates and connecting plates disposed at both ends of the electrode plates. The connecting plates are provided with terminals, and the end caps are provided with mounting holes for the terminals to pass through.

[0009] The beneficial effect is that the terminal blocks pass through the mounting holes, and the electrode stack is connected to the tank body through the terminal blocks and mounting holes.

[0010] Preferably, as an improvement, the same electrode plate is connected to at most one connecting plate, and the electrode plate has at most one end for engaging with the connecting plate. The slot is interference-fitted with the connecting plate, and several electrode plates are connected through an insulated double-ended screw.

[0011] The beneficial effects are as follows: This structure can avoid redundant electrode plate connections and assembly interference. The slot and the connecting plate are interference-fitted, making the assembly firm and the process simple. The insulated double-headed screws connect each electrode plate, which can not only ensure uniform electrode plate spacing, but also effectively block the current conduction between electrode plates, prevent short circuits, and improve reaction stability and operational safety.

[0012] Preferably, as an improvement, the electrode plate has a through hole for the insulating double-ended screw to pass through, the through hole and the insulating double-ended screw are clearance fit, and a vibration assembly is provided between adjacent electrode plates. The vibration assembly includes a connecting sleeve sleeved to the insulating double-ended screw and a rotating cylinder rotatably disposed on the connecting sleeve. One end of the connecting sleeve is embedded in the gap between the through hole and the insulating double-ended screw, the rotating cylinder is provided with an arc-shaped end face, and several grooves are axially formed on the outer side of the rotating cylinder.

[0013] The beneficial effects are as follows: when the sewage flows, the rotating cylinder can be driven to rotate through the groove on the outside of the rotating cylinder. The arc-shaped end face of the rotating cylinder periodically squeezes the electrode plate. With the gap fit of the perforation and the insulated double-headed screw, the electrode plate will produce local micro-vibration, which effectively prevents the reactants from adhering and accumulating on the surface of the electrode plate, ensures that the reactants are evenly dispersed in the water and smoothly discharged from the tank with the water flow, avoids the scale and blockage of the electrode plate, and ensures the continuous and stable progress of the electrochemical oxidation reaction.

[0014] Preferably, as an improvement, the connecting sleeve includes a connecting section for embedding the perforation and a fixed section away from the connecting section. The rotating cylinder is rotatably connected to the fixed section. A bearing is provided between the fixed section and the rotating cylinder. The axial length of the fixed section is less than the axial length of the rotating cylinder. The arc-shaped end face of the rotating cylinder always abuts against the electrode plate.

[0015] Preferably, as an improvement, an inlet pipe is installed at the inlet and an outlet pipe is installed at the outlet on the tank body; flanges for connecting end caps are also provided at both ends of the tank body along its length, and the distance between the bottom of the flange and the bottom of the tank body is greater than the distance between the bottom of the inlet and the bottom of the tank body. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention; Figure 2 This is a front view of the overall structure of an embodiment of the present invention; Figure 3 This is a top view of the overall structure of an embodiment of the present invention; Figure 4 This is a test diagram of the overall structure of an embodiment of the present invention; Figure 5 This is an embodiment of the present invention. Figure 2 Schematic diagram of the cross-sectional structure along the AA direction; Figure 6 This is a schematic diagram of the exploded structure of the tank in an embodiment of the present invention; Figure 7 This is a schematic diagram of the electrode assembly structure according to an embodiment of the present invention; Figure 8 This is a schematic diagram of the electrode stack structure according to an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of the vibration assembly installed between the electrode plates according to an embodiment of the present invention; Figure 10 This is a cross-sectional structural diagram of the vibration assembly installed between the electrode plates according to an embodiment of the present invention; Figure 11 This is a partial structural diagram of the connection between the electrode plate and the connecting plate in an embodiment of the present invention. Detailed Implementation

[0017] The following detailed description illustrates the specific implementation method: The reference numerals in the accompanying drawings include: tank 1, inlet 11, outlet 12, flow guide baffle 13, reaction passage 131, flange 14, end cap 141, mounting hole 1411, electrode stack 2, electrode plate 21, slot 211, perforation 212, connecting plate 22, terminal block 23, insulated double-ended screw 24, vibration assembly 3, connecting sleeve 31, rotating cylinder 32, groove 321.

[0018] Example 1 The basic implementation examples are as follows: Figures 1-11 As shown, Figure 1 , Figure 2 , Figure 4 The multi-chamber trough-type electrochemical oxidation reactor shown includes a cuboid trough 1. An inlet 11 is provided at the bottom of one end of the trough 1 along its length, and an outlet 12 is provided at the top of the other end. Water pipes are installed at both the inlet 11 and the outlet 12, which are respectively the inlet pipe and the outlet pipe, forming a bottom-inlet and top-outlet push-flow channel inside the trough 1. Two flow guide baffles 13 are vertically arranged in the inner cavity of the trough 1 along its length. The flow guide baffles 13 are arranged in a square arch shape and occupy half of the cross-section of the trough 1 in the vertical direction. The two flow guide baffles 13 are arranged alternately, dividing the inner cavity of the trough 1 into multiple reaction chambers connected in series. The two flow guide baffles 13 enclose a reaction passage 131 with a rectangular cross-section in the length direction of the trough 1.

[0019] like Figures 6-7As shown, flanges 14 for connecting end caps 141 are provided at both ends of the tank body 1 along its length. The distance between the bottom of the flange 14 and the bottom of the tank body 1 is greater than the distance between the bottom of the inlet and the bottom of the tank body 1. End caps 141 are provided at both ends of the tank body 1 and are used to install the end caps 141 onto the flanges 14. Both the flanges 14 and the end caps 141 have threaded holes. The end caps 141 are installed onto the flanges 14 by bolts. Electrode assemblies are installed in the tank body 1 along its length through the end caps 141. The electrode assemblies include 6 electrode stacks 2. Each electrode stack 2 includes several equally spaced electrode plates 21 and connecting plates 22 connecting the two ends of the electrode plates 21. Along the arrangement direction of the electrode stacks 2, the slots 211 of adjacent electrode plates 21 are alternately opened at different positions. On one side, the slot 211 of the first electrode plate 21 is opened at the left end and is engaged with the left end connecting plate 22; the slot 211 of the second electrode plate 21 is opened at the right end and is engaged with the right end connecting plate 22; the slot 211 of the third electrode plate 21 is opened at the left end and is engaged with the left end connecting plate 22, and so on, so that each electrode plate 21 is alternately engaged and fixed with the two end connecting plates 22; the slot 211 and the corresponding connecting plate 22 are interference fit, and several electrode plates 21 and the two end connecting plates 22 form a stable overall structure of electrode stack 2; several electrode plates 21 in the same electrode stack 2 are connected by insulated double-ended bolts, and the electrode plate 21 has a through hole 212 through which a common insulated double-ended bolt 24 passes. The insulated double-ended bolt is made of polyetheretherketone material.

[0020] Two terminals 23 are fixedly installed on the connecting plate 22. The terminals 23 include a threaded section near the connecting plate 22 and a terminal plate fixed to the threaded section. The end cover 141 has 6 sets of mounting holes 1411 for the terminals 23 to pass through. Each set of mounting holes 1411 has two holes. During installation, the terminals 23 pass through the mounting holes 1411 and are threadedly connected to the threaded section through the insulating cap nut. The outer side of the end cover 141 has a countersunk hole for the insulating cap nut to be inserted. A sealing gasket is provided between the insulating cap nut and the countersunk hole. In addition, a sealing ring is provided between the end cover 141 and the flange 14. The 6 sets of electrode stacks 2 are connected together between the end covers 141 to form an electrode assembly with a rectangular cross section. The electrode assembly passes through the reaction passage 131. The flow guide baffle 13 is clearance-fitted with the edge of the electrode assembly.

[0021] like Figures 3-5As shown, the external length of the tank is 5.0-6.0m, the width is 1.5-1.8m, and the height is 2.0-2.5m. The effective volume of the tank is 12m³, the water flow rate is 20m³ / h, and the hydraulic retention time is 36 minutes. The wastewater flows under high load within the tank. Furthermore, this application designs the tank 1 as a long and narrow shape, employing a push-flow flow pattern with water entering from the long bottom end and exiting from the long top end, forming a downward-upward longitudinal push-flow path. This design aligns the water flow with the upward direction of hydrogen, facilitating gas escape. The guide baffle 13 divides the tank 1 into multiple series reaction chambers. This vertical baffle structure effectively eliminates longitudinal flow deviation within the tank 1. The dead zone significantly enhances mass transfer efficiency compared to empty tanks or horizontal baffles; at the same time, the flow guide baffle 13 disperses the large flow rate to each chamber for treatment, avoiding local overload. The tank design is compatible with 40-foot container transportation, enabling factory prefabrication and rapid on-site hoisting, ensuring that a single unit can replace 6-10 traditional parallel units, reducing the floor space by more than 65%; the electrode plates 21 of the electrode stack 2 are continuously arranged along the length of the tank 1, and can be powered by a single power supply or dual-end power supply, simplifying the power system. Furthermore, the hydraulic partitioning effect of the baffles avoids water flow short circuits, reducing electrical connection nodes by 80% compared to traditional methods, and meeting the high reliability requirements of continuous operation and low maintenance.

[0022] The specific implementation process is as follows: During use, wastewater enters from the bottom of one end of tank 1 through the inlet pipe, and is gradually advanced in the series reaction chamber along the bottom-in, top-out push-flow channel, making full contact with the electrode components to carry out an electrochemical oxidation reaction. The treated wastewater is discharged from the top of the other end of tank 1 through the outlet pipe, completing continuous and efficient treatment.

[0023] Example 2 The difference between Example 2 and Example 1 is as follows: like Figures 8-11As shown, the perforation 212 is clearance-fitted with the insulated double-ended screw 24. A vibration assembly 3 can be installed between adjacent pole plates 21 at the location of the insulated double-ended screw 24. The vibration assembly 3 includes a connecting sleeve 31 sleeved on the insulated double-ended screw 24 and a rotating cylinder 32 rotatably disposed on the connecting sleeve 31. The connecting sleeve 31 includes a connecting section for embedding into the perforation 212 and a fixed section away from the connecting section and connected to the connecting section. The wall thickness of the connecting section is greater than the gap between the perforation 212 and the insulated double-ended screw. Therefore, after the connecting section is embedded into the perforation 212, there is an interference fit between the connecting section and the insulated double-ended screw, and between the perforations 212. Thus, the connecting section installs the vibration assembly 3 between adjacent pole plates 21. The rotating cylinder 32 is rotatably disposed on the fixed section. The rotating cylinder 32 and the fixed section are... A bearing is installed between the fixed section and the rotating cylinder 32. The axial length of the fixed section is less than the axial length of the rotating cylinder 32. The end of the rotating cylinder 32 near the other electrode plate 21 is provided with an arc-shaped end face. The arc-shaped end face always abuts against the electrode plate 21. Several grooves 321 are axially opened on the outer ring of the rotating cylinder 32. The arc-shaped end face has a convex highest point and a concave lowest point. When wastewater flows through, the water flow acts on the grooves 321 to drive the rotating cylinder 32 to rotate around the connecting sleeve 31. The arc-shaped end face periodically squeezes the electrode plate 21 with the rotation. The gap fit between the electrode plate 21 and the insulated double-headed screw 24 is matched. In addition, the electrode plate 21 only vibrates locally in the vibration component 3 and is reset by the elasticity of the electrode plate 21 itself. The connecting section is made of fluororubber material, and the fixed section, rotating cylinder 32, and bearing are all made of polyetheretherketone material.

[0024] During use, due to the gap between the flow guide baffle 13 and the electrode assembly, the flow velocity of wastewater in the reaction chamber is less than the flow velocity at the gap between the flow guide baffle 13 and the electrode plate 21. Therefore, the water pressure at the gap is less than the water pressure in the reaction chamber. When the wastewater flows from the reaction chamber through the reaction passage 131, the water flow is inclined upward, and the water flow just impacts the groove 321 on the rotating cylinder 32, causing the rotating cylinder 32 to rotate. When the highest point of the arc-shaped end face abuts against the electrode plate 21, the electrode plate 21 is locally squeezed and slightly expanded outward. When the lowest point of the arc-shaped end face abuts against the electrode plate 21, the electrode plate 21 returns to its original position. This repeated pushing and colliding of the electrode plate 21... 1. Localized micro-changes can cause the electrode plate 21 to vibrate, thereby preventing pollutants and reactants from adhering and accumulating on the surface of the electrode plate 21, ensuring that pollutants are evenly dispersed in the water and smoothly discharged from the tank 1 with the water flow, preventing scale buildup and blockage of the electrode plate 21, ensuring the continuous, stable and efficient electrochemical oxidation reaction, improving wastewater treatment effect, extending electrode lifespan, and reducing equipment operation and maintenance costs; when the wastewater pressure is low, the rotational power of the rotating cylinder 32 is small and insufficient to drive the localized micro-expansion of the electrode plate 21, but the slight impact of the continuous rotation of the end face of the rotating cylinder 32 can also cause the electrode plate 21 to vibrate slightly.

[0025] The above descriptions are merely embodiments of the present invention, and common knowledge such as specific technical solutions and / or characteristics are not described in detail here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A multi-chamber trough-type electrochemical oxidation reactor, characterized in that: It includes a sealed tank, electrode assembly and several flow guide baffles; the tank is a long and narrow tank, with an inlet at the bottom of one end along the length of the tank and an outlet at the top of the other end, forming a bottom-inlet and top-outlet push-flow channel; The flow guide baffles are vertically installed in the inner cavity of the tank along the length of the tank. The flow guide baffles are arched and occupy half of the space of the tank cross section in the vertical direction. Several flow guide baffles are arranged alternately up and down to divide the inner cavity of the tank into multiple reaction chambers in series. Several flow guide baffles form a reaction passage through which the electrode assembly passes. The electrode assembly spans across the tank in the left and right directions. The cross-sectional shape of the reaction passage is the same as that of the electrode assembly. The electrode assembly and the flow guide baffles are fitted with a clearance.

2. The reactor according to claim 1, characterized in that: End caps are installed at both ends of the tank along its length, and the electrode assembly is installed in the tank through the end caps at both ends.

3. The reactor according to claim 2, characterized in that: The electrode assembly includes several sets of electrode stacks, each set including several equally spaced electrode plates and connecting plates at both ends of the electrode plates. The connecting plates are provided with terminals, and the end caps are provided with mounting holes for the terminals to pass through.

4. The reactor according to claim 3, characterized in that: The same electrode plate is connected to at most one connecting plate. The electrode plate has at most one end for engaging with the connecting plate. The slot is interference-fitted with the connecting plate. Several electrode plates are connected through an insulated double-ended screw.

5. The reactor according to claim 4, characterized in that: The electrode plate has a through hole for the insulating double-ended screw to pass through. The through hole and the insulating double-ended screw are fitted with a clearance. A vibration assembly is provided between adjacent electrode plates. The vibration assembly includes a connecting sleeve that is sleeved on the insulating double-ended screw and a rotating cylinder that is rotatably set on the connecting sleeve. One end of the connecting sleeve is embedded in the gap between the through hole and the insulating double-ended screw. The rotating cylinder has an arc-shaped end face and several grooves are axially formed on the outer side of the rotating cylinder.

6. The reactor according to claim 5, characterized in that: The connecting sleeve includes a connecting section for embedding through the perforation and a fixed section away from the connecting section. The rotating cylinder is rotatably connected to the fixed section. A bearing is provided between the fixed section and the rotating cylinder. The axial length of the fixed section is less than the axial length of the rotating cylinder. The arc-shaped end face of the rotating cylinder is always in contact with the electrode plate.

7. The reactor according to claim 1, characterized in that: The tank has an inlet pipe installed at the inlet and an outlet pipe installed at the outlet. Flanges for connecting end caps are also installed at both ends of the tank along its length. The distance between the bottom of the flange and the bottom of the tank is greater than the distance between the bottom of the inlet and the bottom of the tank.

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