A system for electrolytic desulfurization wastewater

Abstract

This invention relates to the field of sodium hypochlorite preparation equipment, and more particularly to a system for electrolytic desulfurization wastewater, comprising a three-unit block, an electrolytic cell assembly, a drying block, a hydrogen collection block, a control cabinet, a rectifier power supply, a nitrogen addition block, a neutralization dosing and outlet pipe. This invention treats ions other than ammonia nitrogen and COD in the three-unit block, adjusts the pH, and uses electrolysis technology to electrolyze chloride and hydrogen ions in the wastewater to produce hydrogen and hypochlorite. Hypochlorite effectively reduces ammonia nitrogen and COD in the wastewater. The generated hydrogen passes through the drying block and the hydrogen collection block, converting gaseous hydrogen into liquid hydrogen for collection, ensuring stable and safe system operation. The quality of the wastewater after electrolysis is monitored online; if it meets the standards, it can be directly used or discharged, solving the problems of water use and wastewater discharge in power plants, while the generated hydrogen is safely used in production.

Description

Technical Field

[0001] This invention relates to the technical field of sodium hypochlorite preparation equipment, specifically a system for electrolytic desulfurization wastewater. Background Technology

[0002] Currently, desulfurization wastewater is typically treated using breakpoint chlorination or electrolytic desulfurization. However, the current system has the following problems:

[0003] 1. Fluctuations in desulfurization wastewater and its volume, along with the electrode lifespan during electrolysis, become limiting factors in the electrolysis process;

[0004] 2. The mixed gas produced after the consumption of ammonia nitrogen and COD during electrolysis has low purity, posing safety hazards during electrolysis, and the direct discharge of hydrogen wastes renewable resources;

[0005] 3. The quality and flow rate of desulfurization wastewater are unstable. The unstable water quality causes some of the water after electrolysis to be substandard and the unstable flow rate causes the equipment to shut down or restart frequently due to low flow, resulting in a shortened electrode life.

[0006] 4. Due to the high hardness of some desulfurization wastewater, precipitation is easily generated during electrolysis and adheres to the cathode. Some of the precipitation cannot be completely removed by acid washing, so it is necessary to dismantle and clean it regularly. The dismantling of most electrolytic cells is complicated and maintenance is difficult.

[0007] No solutions have yet been proposed for the relevant technical issues. Summary of the Invention

[0008] In response to the problems in related technologies, this invention proposes a system for electrolytic desulfurization wastewater to overcome the aforementioned technical problems in existing related technologies. The purpose of this invention is to fully utilize the high chloride ions in the desulfurization wastewater to degrade ammonia nitrogen and COD in the wastewater, while safely collecting and using the degraded byproduct hydrogen gas, which facilitates equipment maintenance.

[0009] To achieve the above objectives, the present invention provides the following technical solution: a system for electrolytic desulfurization wastewater, comprising a triple-tank block, an electrolytic cell assembly, a drying block, a hydrogen collection block, a control cabinet, a rectifier power supply, a nitrogen addition block, a neutralization dosing and outlet pipe. The triple-tank block includes a triple tank, pipelines, an online conductivity meter and a flow meter. The triple-tank block is connected to the electrolytic cell assembly. The electrolytic cell assembly includes an electrolytic cell, a pressure switch, a pH meter, an ultrasonic level gauge and a first electric valve installed on the electrolytic cell. The electrolytic cell includes a base, on which an end anode assembly is fixedly installed. The base also includes an intermediate electrode plate, an end cathode assembly and a cover plate. The cover plate has an opening and is connected to the drying block via the first electric valve. The base is movably connected to the end cathode assembly via a rolling bearing.

[0010] Preferably, the surface of the base is coated with polytetrafluoroethylene (PTFE), and an intermediate plate is provided at the center of the base. A first cavity and a second cavity are respectively provided on both sides of the intermediate plate. A first through hole is provided on the intermediate plate. A first mounting hole, a second mounting hole, and a third mounting hole are respectively provided on the second cavity. The ultrasonic level gauge is installed on the first mounting hole, the pressure switch and pH meter are installed on the second mounting hole, and the outlet pipe is installed on the third mounting hole. An installation groove is provided on the first cavity, and the end anode assembly, the intermediate electrode plate, and the end cathode assembly are all installed inside the installation groove.

[0011] Preferably, the end anode assembly includes an end anode frame, a sealing strip is adhered to the end anode frame, a wiring board is also provided on the end anode frame, an end anode is welded onto the wiring board, a sealing groove is provided on the end anode frame, a first sealing gasket is provided in the sealing groove, the end anode and the wiring board are fixedly connected to the end anode frame by fasteners, and an inlet is provided on the end anode frame and the wiring board.

[0012] Preferably, the intermediate electrode plate includes an intermediate electrode frame, on which a cathode and an anode are mounted. A second sealing gasket is also provided on the intermediate electrode frame. An exhaust hole is provided on the intermediate electrode frame. The cathode is made of Hastelloy alloy frame and multiple layers of Hastelloy alloy wire mesh are mounted on the cathode.

[0013] Preferably, the end cathode assembly includes an end cathode frame, a plurality of hydraulic piston cylinders, an end terminal block, and an end cathode, wherein the two ends of the hydraulic piston cylinders are respectively connected to the end cathode frame and the middle plate.

[0014] Preferably, the hydraulic piston cylinder is provided with an oil inlet and an oil return port at both ends.

[0015] Preferably, the outlet pipe includes a second electric valve, a third electric valve, a fourth electric valve, an online residual chlorine analyzer, an ion analyzer, and a circulation pump.

[0016] Compared with the prior art, the beneficial effects of the present invention are:

[0017] This invention relates to a system for electrolytic desulfurization wastewater. It utilizes a three-compartment block to treat ions other than ammonia nitrogen and COD, adjusts the pH, and electrolyzes chloride and hydrogen ions in the wastewater to produce hydrogen and hypochlorite. Hypochlorite effectively reduces ammonia nitrogen and COD in the wastewater. The generated hydrogen passes through a drying block and a hydrogen collection block to convert gaseous hydrogen into liquid hydrogen for collection, ensuring stable and safe system operation. The system also provides online monitoring of the wastewater quality after electrolysis; once qualified, it can be directly used or discharged, solving the problems of water use and wastewater discharge in power plants, while the generated hydrogen is safely used in production. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the electrolytic cell of the present invention;

[0020] Figure 3 This is a schematic diagram of the structure of the end anode assembly of the present invention;

[0021] Figure 4 This is a schematic diagram of the structure of the base of the present invention;

[0022] Figure 5 This is a schematic diagram of the cross-sectional structure of the base of the present invention;

[0023] Figure 6 This is a schematic diagram of the structure of the end cathode assembly of the present invention.

[0024] In the attached diagram, the following are the reference numerals: 1. Triple-unit block; 2. Electrolytic cell assembly; 3. Drying block; 4. Hydrogen collection block; 5. Control cabinet; 6. Rectifying power supply; 7. Nitrogen addition block; 8. Neutralization dosing device; 9. Outlet pipe; 10. Flow meter; 11. Electrolytic cell; 12. Pressure switch; 13. pH meter; 14. Ultrasonic level gauge; 15. First electric valve; 16. Base; 17. Anode assembly; 18. Intermediate electrode plate; 19. Cathode assembly; 20. Cover plate; 21. Cathode; 22. Intermediate electrode plate; 23. 24. First cavity; 25. Second cavity; 26. First through hole; 27. Mounting groove; 28. End anode frame; 29. ​​Sealing strip; 30. Terminal block; 31. End anode; 32. Intermediate electrode frame; 33. Cathode; 34. Anode; 35. Second sealing gasket; 36. End cathode frame; 37. Hydraulic piston cylinder; 38. End terminal block; 39. Second electric valve; 40. Third electric valve; 41. Fourth electric valve; 42. Online residual chlorine analyzer; 43. Ion analyzer; 44. Circulating pump; 45. Rolling bearing. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

[0026] Example 1

[0027] Please see Figure 1-6This invention proposes a technical solution for a system for electrolytic desulfurization wastewater: A system for electrolytic desulfurization wastewater includes a three-unit block 1, an electrolytic cell assembly 2, a drying block 3, a hydrogen collection block 4, a control cabinet 5, a rectifier power supply 6, a nitrogen addition block 7, a neutralization dosing device 8, and an outlet pipe 9. The three-unit block 1 includes a three-unit box, pipelines, an online conductivity meter, and a flow meter 10. Specifically, the three-unit block 1 can treat ions other than ammonia nitrogen and COD, and adjust the pH; the generated hydrogen passes through the drying block 3 and the hydrogen collection block 4, converting gaseous hydrogen into liquid hydrogen for collection, ensuring stable and safe system operation; the effluent flow rate is monitored by the conductivity meter 10, and the treated water is input into the electrolytic cell assembly 2; the hydrogen collection block 4 uses a supported catalyst with dual hydrogenation and dehydrogenation functions prepared by loading Ru and Pd active components, collecting, purifying, and liquefying the dried mixed gas; the three-unit block... 1. Connected to the electrolytic cell assembly 2, the electrolytic cell assembly 2 includes an electrolytic cell 11, a pressure switch 12, a pH meter 13, an ultrasonic level gauge 14, and a first electric valve 15 installed on the electrolytic cell 11. Specifically, the electrolytic cell 11 uses electrolysis technology to electrolyze chloride ions and hydrogen ions in wastewater to produce hydrogen gas and hypochlorite ions. Hypochlorite ions can effectively reduce ammonia nitrogen ions and COD in wastewater. The electrolytic cell 11 includes a base 16, on which an end anode assembly 17 is fixedly installed. The base 16 is also provided with an intermediate electrode plate 18, an end cathode assembly 19, and a cover plate 20. The cover plate 20 has openings and is connected to the drying block 3 through the first electric valve 15. The base 16 is movably connected to the end cathode assembly 19 through a rolling bearing 44. Specifically, the intermediate electrode plate 18 can move left and right on the base 16, and several intermediate electrode plates 18 are provided. The end cathode assembly 19 can move left and right.

[0028] Please see Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the surface of the base 16 is coated with polytetrafluoroethylene. A central plate 22 is provided at the center of the base 16. A first cavity 23 and a second cavity 24 are respectively provided on both sides of the central plate 22. A first through hole 25 is provided on the central plate 22. A first mounting hole, a second mounting hole and a third mounting hole are respectively provided on the second cavity 24. An ultrasonic level gauge 14 is installed on the first mounting hole. A pressure switch 12 and a pH tester 13 are installed on the second mounting hole. An outlet pipe 9 is installed on the third mounting hole. A mounting groove 26 is provided on the first cavity 23. The end anode assembly 17, the intermediate electrode plate 18 and the end cathode assembly 19 are all installed inside the mounting groove 26.

[0029] In this embodiment, the base 16 is made of Q235-B material, and the intermediate electrode plate 18 restricts the forward and backward movement and up and down movement of the ultrasonic level gauge 14, pressure switch 12, pH meter 13, and outlet pipe 9, allowing only left and right movement.

[0030] Please see Figure 3 As shown, the end anode assembly 17 further includes an end anode frame 27, a sealing strip 28 is adhered to the end anode frame 27, a terminal block 29 is also provided on the end anode frame 27, an end anode 30 is welded to the terminal block 29, a sealing groove is provided on the end anode frame 27, a first sealing gasket is provided in the sealing groove, the end anode 30 and the terminal block 29 are fixedly connected to the end anode frame 27 by fasteners, and an inlet is provided on the end anode frame 27 and the terminal block 29.

[0031] In this embodiment, the end anode frame 27 is made of acrylic material, which is transparent and can be seen from the inside; the inlet is used for electrolyte entry, and the end anode 30 adopts a porous titanium mesh plate with a RuIrCoLaTaTi hexa-element coating; the end anode assembly 17, the intermediate electrode plate 18 and the end cathode assembly 19 are installed in sequence according to the principle that the anode is directly opposite the cathode. The part generated during the electrolysis process is discharged through the top and enters the drying block 3 and the hydrogen collection block 4, and the part that is not discharged flows in with the electrolyte.

[0032] Please see Figure 2 As shown, the intermediate electrode plate 18 further includes an intermediate electrode frame 31, on which a cathode 32 and an anode 33 are mounted. A second sealing gasket 34 is also provided on the intermediate electrode frame 31. An exhaust hole is provided on the intermediate electrode frame 31. The cathode 32 adopts a Hastelloy frame and multiple layers of Hastelloy wire mesh are mounted on the cathode 32.

[0033] In this embodiment, the intermediate electrode frame 31 is made of transparent acrylic material, and the exhaust hole discharges the hydrogen and other gases generated during the electrolysis process to the drying block 3 and the hydrogen collection block 4; the surface of the cathode 32 is coated with a PtNiMo coating.

[0034] Please see Figure 6 As shown, the end cathode assembly 19 further includes an end cathode frame 35, a plurality of hydraulic piston cylinders 36, an end terminal block 37 and an end cathode 21. The two ends of the hydraulic piston cylinders 36 are respectively connected to the end cathode frame 35 and the intermediate plate 22.

[0035] Furthermore, the hydraulic piston cylinder 36 is provided with an oil inlet and an oil return port at both ends.

[0036] In this embodiment, when tightening is required, one hydraulic piston cylinder 36 feeds oil into another hydraulic piston cylinder 36 and returns oil to the other. The hydraulic piston cylinder 36 drives the end cathode assembly 19 to move to the left, and vice versa.

[0037] Please see Figure 1 As shown, the outlet pipe 9 further includes a second electric valve 38, a third electric valve 39, a fourth electric valve 40, an online residual chlorine analyzer 41, an ion analyzer 42, and a circulation pump 43.

[0038] In this embodiment, when the electric valve at the outlet is opened, the residual chlorine and ion levels at the outlet are measured. If the water quality is qualified, it is discharged directly through the third electric valve 39. If it is not qualified, the fourth electric valve 40 is opened, and the water is pumped to the triplet block 1 by the circulation pump 43.

[0039] During equipment operation, desulfurization wastewater is fed into the triple-tank block 1 for sedimentation, flocculation, and pH adjustment. The resulting solution is a slightly alkaline mixed solution containing chloride ions, ammonia nitrogen, and COD. This solution then flows through flow meter 10 and conductivity meter into the electrolytic cell assembly 2. The conductivity meter and flow meter 10 transmit electrical signals to the control unit, which in turn controls the rectifier power supply 6 to output a specific DC current based on the conductivity.

[0040] The rectifier power supply 6 applies a certain DC current to the anode assembly 17 and cathode assembly 19 of the electrolytic cell. Due to the potential difference between the anode 33 and cathode 32 in the anode assembly 17, intermediate electrode plate 18, and cathode assembly 19, an electrolytic cell is formed in the electrolyte. - At the anode, it loses electrons and is oxidized to Cl2. Cl2 combines with hydroxide ions in the solution to produce hypochlorite. The strong oxidizing properties of hypochlorite react with COD and ammonia nitrogen in the solution to produce nitrogen gas, carbon oxides, etc. + At the cathode, electrons are gained and the solution is reduced to H2. The specific reaction cycle is NaCl + H2O electrolysis NaClO + H2. The reaction of NaClO with ammonia nitrogen can make the solution slightly acidic. Because the hypochlorite ions generated during electrolysis are consumed, the electrolysis reaction proceeds in the forward direction, thereby improving the conversion of electrical energy into chemical energy and reducing the power consumption of the equipment.

[0041] In the electrolysis process, all the anodes and cathodes in the end anode assembly 17, end cathode assembly 19, and intermediate electrode plate 18 are aligned. Therefore, during electrolysis, the anode 33 on the intermediate electrode plate 18 is connected to the cathode 32, and the Hastelloy coated surface, which is aligned with the anode on the end anode assembly 17, serves as the cathode of the electrolysis chamber. The anode 33 uses a titanium-based mesh coated with a RuIrCoLaTaTi hexa-element coating. The mixed elements improve the coating's service life and reduce the chlorine evolution potential during electrolysis. At the same time, the mesh structure increases the specific surface area, further extending the coating's service life.

[0042] The cathode 32 uses a Hastelloy skeleton, and the multi-layer Hastelloy mesh is welded together and partially brazed with the anode 33 to reduce the number of contact points and reduce the electrolysis power consumption of the equipment. Spraying PtNiMo can reduce the hydrogen evolution potential and reduce the electrolysis power consumption of the equipment.

[0043] The hydrogen gas generated in each electrolysis chamber is discharged through the wide upper hole in the middle, which can not only reduce the ohmic voltage drop of the electrolyte (reduce the power consumption of the equipment).

[0044] The electrolyte mixture containing nitrogen, oxygen and hydrogen produced after electrolysis enters the sealed cavity through the hole on the end cathode assembly 19. The nitrogen in the cavity ensures the safety of the equipment.

[0045] The cavity is equipped with a first electric valve 15, a pressure switch 12, an ultrasonic level gauge 14, and a pH meter 13. The mixed liquid entering the cavity will undergo automatic separation. During the separation process, the pressure inside the cavity will gradually increase. When the pressure rises to the limit of the pressure switch, the electric valve opens, and the gas inside the cavity and the gas generated during electrolysis converge in the drying block, eventually entering the hydrogen collection device. The hydrogen collection device purifies and liquefies the gas for storage, which can be used for power generation when needed.

[0046] The chamber is normally closed. Only when the liquid level reaches the system-set limit or the flow rate at the outlet of the triplet block 1 is insufficient will the first electric valve 15 at the bottom of the chamber open. The online residual chlorine analyzer 41 will then analyze the residual chlorine in the water. If the residual chlorine in the fully mixed electrolyte does not reach the limit, it indicates that COD and ammonia nitrogen have not been completely consumed during electrolysis, and the electrolyte needs to continue entering the triplet block 1 for re-electrolysis. If the residual chlorine is sufficient and the water quality analysis shows that it meets the discharge standards, the wastewater can continue to be used for production or discharged.

[0047] All end anodes 30, end cathodes 21, and intermediate electrode frames 31 are made of acrylic material. This material can be used for internal inspection. When the precipitates generated during electrolysis cannot be completely acid-washed, the machine needs to be disassembled and the electrodes cleaned.

[0048] The installation and disassembly of the electrodes are relatively simple. During installation, the manufacturer only needs to produce the anode assembly 17, intermediate electrode plate 18, and cathode assembly 19, and then install them according to the drawings. Before electrolysis, the piston rod is pressed tightly to ensure that the electrolysis chamber does not leak. When the equipment needs maintenance, the operation is reversed. This installation method also allows for the addition or reduction of the number of electrode plates without affecting the electrolysis process.

[0049] The electrolysis current during the electrolysis process is adjusted according to the conductivity, residual chlorine, and liquid level feedback to ensure that the equipment is always in the optimal operating state.

[0050] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0051] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A system for electrolytic desulfurization wastewater, characterized in that, The system includes a triplex tank (1), an electrolytic cell assembly (2), a drying block (3), a hydrogen collection block (4), a control cabinet (5), a rectifier power supply (6), a nitrogen addition block (7), a neutralization dosing device (8), and an outlet pipe (9). The triplex tank (1) includes a triplex tank, pipelines, an online conductivity meter, and a flow meter (10). The triplex tank (1) is connected to the electrolytic cell assembly (2). The electrolytic cell assembly (2) includes an electrolytic cell (11), a pressure switch (12), a pH meter (13), and an ultrasonic transducer. The electrolytic cell (11) includes a liquid level gauge (14) and a first electric valve (15) mounted on the electrolytic cell (11). The electrolytic cell (11) includes a base (16), on which an end anode assembly (17) is fixedly mounted. The base (16) also includes an intermediate electrode plate (18), an end cathode assembly (19), and a cover plate (20). The cover plate (20) has an opening and is connected to the drying block (3) via the first electric valve (15). The base (16) is connected to the drying block (3) via a rolling shaft. The bearing (44) is movably connected to the end cathode assembly (19). The end anode assembly (17) includes an end anode frame (27), and a terminal block (29) is also provided on the end anode frame (27). An end anode (30) is welded on the terminal block (29). The end anode 30 adopts a porous titanium mesh plate sintered with a RuIrCoLaTaTi hexa-element coating. The intermediate electrode plate (18) includes an intermediate electrode frame (31), and a cathode (32) and an anode (33) are installed on the intermediate electrode frame (31). The intermediate electrode frame (31) is also provided with a second sealing gasket (34). The intermediate electrode frame (31) is provided with an exhaust hole. The cathode (32) adopts a Hastelloy frame. The cathode (32) is equipped with multiple layers of Hastelloy wire mesh. The end cathode assembly (19) includes an end cathode frame (35), several hydraulic piston cylinders (36), an end terminal plate (37), and an end cathode (21). The two ends of the hydraulic piston cylinder (36) are respectively connected to the end cathode frame (35) and the intermediate terminal plate (22).

2. The system for electrolytic desulfurization wastewater according to claim 1, characterized in that: The surface of the base (16) is coated with polytetrafluoroethylene. A middle plate (22) is provided at the center of the base (16). A first cavity (23) and a second cavity (24) are provided on both sides of the middle plate (22). A first through hole (25) is provided on the middle plate (22). A first mounting hole, a second mounting hole and a third mounting hole are provided on the second cavity (24). The ultrasonic level gauge (14) is installed on the first mounting hole. The pressure switch (12) and the pH tester (13) are installed on the second mounting hole. The outlet pipe (9) is installed on the third mounting hole. A mounting groove (26) is provided on the first cavity (23). The end anode assembly (17), the middle electrode plate (18) and the end cathode assembly (19) are all installed inside the mounting groove (26).

3. A system for electrolytic desulfurization wastewater according to claim 1, characterized in that: A sealing strip (28) is attached to the end anode frame (27). A sealing groove is provided on the end anode frame (27). A first sealing gasket is provided in the sealing groove. The end anode (30) and the terminal block (29) are fixedly connected to the end anode frame (27) by fasteners. An inlet is provided on the end anode frame (27) and the terminal block (29).

4. A system for electrolytic desulfurization wastewater according to claim 1, characterized in that... The hydraulic piston cylinder (36) is provided with an oil inlet and an oil return port at both ends.

5. A system for electrolytic desulfurization wastewater according to claim 1, characterized in that... The outlet pipe (9) includes a second electric valve (38), a third electric valve (39), a fourth electric valve (40), an online residual chlorine analyzer (41), an ion analyzer (42), and a circulation pump (43).

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