Water-saving equipment of wet-type electrostatic dust collector

Abstract

The utility model relates to the technical field of water saving of wet-type electrostatic dust collectors, aims to solve the problems that in the prior art, discharged water is difficult to completely absorb, a power plant is difficult to operate, the environmental pollution is serious, the water supplementing amount is large, and the waste of water resources is large, and provides wet-type electrostatic dust collector water saving equipment which comprises a wet-type electrostatic dust collector. The wet-type electrostatic dust collector is provided with a water collecting dust hopper, and the lower part of the water collecting dust hopper is communicated with a neutralization and precipitation treatment device through a pipeline; the neutralization and precipitation treatment device is communicated with the wet-type electrostatic dust collector through a return pipeline; the tail end of the neutralization precipitation treatment device is connected with a drainage pipeline; the water drainage pipeline is provided with a first outer water drainage pipe and a second outer water drainage pipe, the second outer water drainage pipe is connected with a coal-containing wastewater treatment system, and the coal-containing wastewater treatment system is communicated with the wet-type electrostatic dust collector through a water return pipeline. The wet-type electrostatic dust collector has the beneficial effects that the water discharge amount of the wet-type electrostatic dust collector is greatly reduced, the adverse effect on the surrounding water environment of a power plant is reduced, the water replenishing amount of fresh water is saved, and the water resource is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of water saving of wet electrostatic precipitator, in particular to water saving equipment of wet electrostatic precipitator. Background Art

[0002] Wet electrostatic precipitator is mainly used for efficient and continuous removal of pollutants such as fine dust (including PM2.5), droplets and SO3 aerosols in flue gas, as a terminal fine dust removal equipment for the flue gas system of thermal power plants; wet electrostatic precipitator is installed on the outlet flue of the desulfurization absorption tower, so that the smoke emission concentration at the chimney outlet is not more than 3mg / Nm3, which is lower than the ultra-low emission requirement (5mg / Nm3); it is mainly used in thermal power plant projects located close to densely populated, scenic areas and other environmentally sensitive areas.

[0003] According to environmental protection requirements, the external drainage of wet electrostatic precipitators must not be discharged into the sea, and must be reused through methods such as spraying in coal yards and mixing fly ash. However, due to the large amount of external drainage of wet electrostatic precipitators, the above-mentioned reuse methods are difficult to fully absorb, causing difficulties for the operation of power plants. Utility Model Content

[0004] The utility model aims to provide a wet electrostatic precipitator water-saving device to solve the problems in the prior art that the external drainage reuse method is difficult to fully absorb, causes difficulties in power plant operation, causes great environmental pollution, requires large amounts of water replenishment and wastes a lot of water resources.

[0005] The embodiment of the utility model is achieved as follows:

[0006] The utility model embodiment provides a wet electrostatic precipitator water-saving device, which includes a wet electrostatic precipitator;

[0007] The wet electrostatic precipitator has a water collecting hopper, a neutralization and sedimentation treatment device is provided at the lower part of the water collecting hopper, and the neutralization and sedimentation treatment device is connected to the water collecting hopper through a pipeline;

[0008] The neutralization precipitation treatment device has a return pipeline, and the two ends of the return pipeline are respectively connected to the neutralization precipitation treatment device and the wet electrostatic precipitator;

[0009] A drainage pipeline is provided at the tail end of the neutralization and sedimentation treatment device, and one end of the drainage pipeline is connected to the neutralization and sedimentation treatment device;

[0010] The above-mentioned drainage pipeline has a first external drainage pipe and a second external drainage pipe. The end of the above-mentioned second external drainage pipe away from the above-mentioned neutralization and sedimentation treatment device is provided with a coal-containing wastewater treatment system. The above-mentioned second external drainage pipe is connected to the above-mentioned coal-containing wastewater treatment system. A return water pipeline is provided at the tail end after treatment by the above-mentioned coal-containing wastewater treatment system. The two ends of the above-mentioned return water pipeline are respectively connected to the tail end of the above-mentioned coal-containing wastewater treatment system and the above-mentioned wet electrostatic precipitator.

[0011] When in use, first, the water flushed from the wet electrostatic precipitator will flow into the water collecting hopper, and then discharged into the neutralization and sedimentation treatment device through the water collecting hopper. After the neutralization and sedimentation treatment device treats the water, most of the water will return to the wet electrostatic precipitator through the return pipeline for reuse, a small amount of water will flow into the coal-containing wastewater treatment system through the second external drainage pipe of the drainage pipeline, and a small amount of water containing dust particles will be discharged through the first external drainage pipe. The water treated by the coal-containing wastewater treatment system will flow into the wet electrostatic precipitator through the return water pipeline for reuse, thereby minimizing the amount of water discharged outside the wet electrostatic precipitator.

[0012] A wet electrostatic precipitator water-saving device disclosed in this embodiment further treats the water to be discharged by adding the above-mentioned coal-containing wastewater treatment system, thereby realizing secondary recovery and reuse of the water. As a result, the wet electrostatic precipitator water-saving device has the beneficial effects of greatly reducing the amount of water discharged from the wet electrostatic precipitator, alleviating the adverse effects on the water environment around the power plant, saving the amount of fresh water replenishment and saving water resources.

[0013] Optionally: a plurality of dust collecting electrodes are provided on both sides of the upper portion of the water collecting hopper, and the plurality of dust collecting electrodes are parallel to each other and spaced apart.

[0014] With such arrangement, the plurality of dust collecting electrodes can capture dust particles driven by the electric field force, and then a continuous water film is formed by spraying water to the plurality of dust collecting electrodes, and the flowing water flushes the captured dust particles into the ash hopper and is discharged with the water.

[0015] Optionally: a plurality of nozzles are provided at the top of the plurality of dust collecting electrodes, and the plurality of nozzles correspond to the gaps between the plurality of dust collecting electrodes.

[0016] With such an arrangement, several of the above-mentioned nozzles can spray water mist toward the discharge electrode and the corona area. The water mist is charged and split into further atomized in the strong corona field formed by the thorn electrode. Here, the electric field force, the collision interception, adsorption and condensation of the charged water mist work together to capture the dust particles.

[0017] Optionally: one end of the return pipeline is connected to the neutralization precipitation treatment device, and the other end of the return pipeline is connected to the plurality of nozzles.

[0018] With such arrangement, when the water discharged from the water collecting ash hopper is processed by the neutralization sedimentation treatment device, most of it will be returned to the several nozzles through the return pipeline for recycling and reused as flushing water for the wet electrostatic precipitator, which is beneficial to saving the amount of fresh water replenishment and, at the same time, saving water resources.

[0019] Optionally: an alkali storage tank is provided at the lower part of the water collecting ash hopper, and the alkali storage tank is connected to the water collecting ash hopper through a pipeline.

[0020] With such arrangement, since the water in the water collecting ash hopper contains not only dust particles but also acidic corrosion, it is necessary to discharge alkaline substances through the alkali storage tank and mix them with the acidic water discharged from the water collecting ash hopper to achieve acid-base neutralization. The acid-base neutralized water is then discharged into the drainage tank, which effectively avoids acidic water from corroding the equipment and ensures the service life of the equipment.

[0021] Optionally: a drainage box is further provided at the lower part of the water collecting ash hopper, and a water inlet of the drainage box is connected to the water collecting ash hopper and the alkali storage tank through a pipeline.

[0022] With such arrangement, the drainage box has the function of neutralizing the sediment, which is beneficial for treating the water discharged from the water collecting ash hopper.

[0023] Optionally: the drainage box has a first water outlet and a second water outlet, the first water outlet is provided with a circulating water tank, the water inlet of the circulating water tank is connected to the first water outlet, one end of the return pipeline is connected to the water outlet of the circulating water tank, and the other end of the return pipeline is connected to the plurality of nozzles;

[0024] One end of the drainage pipeline is connected to the second water outlet.

[0025] With such arrangement, after the water in the drainage tank is treated, most of the water will be discharged into the circulating water tank through the first water outlet and the water inlet of the circulating water tank for treatment, and the treated water in the circulating water tank will be returned to the wet electrostatic precipitator through the return pipeline for reuse and flushing, which greatly reduces the amount of water discharged outside the wet electrostatic precipitator and effectively reduces the adverse effects on the water environment around the power plant. At the same time, it saves the amount of fresh water replenishment and water resources. A small amount of water mixed with dust particles is discharged through the second water outlet and the drainage pipeline, thereby improving the water quality of most of the reused water to maintain the normal and stable operation of the equipment.

[0026] Optionally: a supply water tank is provided between the above-mentioned return water pipeline and the plurality of above-mentioned nozzles, one end of the above-mentioned return water pipeline close to the above-mentioned supply water tank is connected to the water inlet of the above-mentioned supply water tank, a supply water pipe is provided between the above-mentioned supply water tank and the plurality of above-mentioned nozzles, and both ends of the above-mentioned supply water pipe are respectively connected to the plurality of above-mentioned nozzles and the water outlet of the above-mentioned supply water tank.

[0027] With such arrangement, water mixed with dust particles is discharged from the above-mentioned drainage pipeline into the above-mentioned coal-containing wastewater treatment system for further treatment, the treated water flows into the above-mentioned feed water tank through the above-mentioned return pipeline, the water in the above-mentioned feed water tank flows into the above-mentioned several nozzles through the above-mentioned feed water pipe for reuse and flushing, and the water discharged from the above-mentioned drainage pipeline is further treated and recycled here, so as to minimize the external discharge volume of the above-mentioned wet electrostatic precipitator. After flocculation and sedimentation, the solid suspended matter particle content in the wastewater treatment system is reduced to 200 mg / l (meeting the reuse requirement of flushing water of the above-mentioned wet electrostatic precipitator), and then pumped to the above-mentioned feed water tank to be reused as flushing water.

[0028] Optionally: the above-mentioned supply water tank is connected to a water supply pipe, and the above-mentioned water supply pipe is provided with a water supply valve.

[0029] With such arrangement, the water supply pipe can replenish the water supply tank with fresh water in time. Since the equipment will still lose some water after long-term operation, the water supply pipe can maintain water balance, and the water supply valve can control the time and amount of fresh water replenishment.

[0030] Optionally: the water supply pipe, the drainage pipe and the return pipe are all provided with a pump and a first switch;

[0031] The return water pipeline and the pipeline of the alkali storage tank are provided with a second switch.

[0032] With such arrangement, the water in the above-mentioned supply water pipe, the above-mentioned drainage pipeline and the above-mentioned return pipeline is powered by the above-mentioned pump, and the above-mentioned first switch can control the switches of the above-mentioned supply water pipe, the above-mentioned drainage pipeline and the above-mentioned return pipeline; and the above-mentioned second switch can control the pipeline switches of the above-mentioned return water pipeline and the above-mentioned alkali storage tank, which is conducive to the normal operation of the equipment.

[0033] Based on the above description, the wet electrostatic precipitator water-saving device disclosed by the utility model has the beneficial effects of greatly reducing the external water discharge of the wet electrostatic precipitator, alleviating the adverse impact on the water environment around the power plant, saving the amount of fresh water replenishment and saving water resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the utility model and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1This is a system flow chart of a wet electrostatic precipitator water-saving device in an embodiment of the utility model.

[0036] Icons: 1-wet electrostatic precipitator, 2-water collecting ash hopper, 3-neutralization and sedimentation treatment device, 4-return pipeline, 5-drainage pipeline, 6-first external drainage pipe, 7-second external drainage pipe, 8-coal-containing wastewater treatment system, 9-return water pipeline, 11-dust collecting electrode, 12-nozzle, 13-alkali storage tank, 14-drainage tank, 15-first water outlet, 16-second water outlet, 17-circulating water tank, 18-supply water tank, 19-supply water pipe, 20-supply water pipe, 21-supply water valve, 22-pump, 23-first switch, 24-second switch. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example

[0040] See also Figure 1 , this embodiment proposes a wet electrostatic precipitator water-saving device, including a wet electrostatic precipitator 1;

[0041] The wet electrostatic precipitator 1 has a water collecting ash hopper 2, a neutralization and sedimentation treatment device 3 is provided at the lower part of the water collecting ash hopper 2, and the neutralization and sedimentation treatment device 3 is connected to the water collecting ash hopper 2 through a pipeline;

[0042] The neutralization precipitation treatment device 3 has a return pipeline 4, and the two ends of the return pipeline 4 are respectively connected to the neutralization precipitation treatment device 3 and the wet electrostatic precipitator 1;

[0043] A drainage pipeline 5 is provided at the tail end of the neutralization sedimentation treatment device 3, and one end of the drainage pipeline 5 is connected to the neutralization sedimentation treatment device 3;

[0044] The drainage pipeline 5 comprises a first external drainage pipe 6 and a second external drainage pipe 7. An end of the second external drainage pipe 7 away from the neutralization and sedimentation treatment device 3 is provided with a coal-containing wastewater treatment system 8. The second external drainage pipe 7 is connected to the coal-containing wastewater treatment system 8. A return water pipeline 9 is provided at the tail end after treatment by the coal-containing wastewater treatment system 8. Both ends of the return water pipeline 9 are respectively connected to the tail end of the coal-containing wastewater treatment system 8 and the wet electrostatic precipitator 1.

[0045] When in use, first, the water flushed from the wet electrostatic precipitator 1 will flow into the water collecting hopper 2, and the water will be discharged into the neutralization sedimentation treatment device 3 through the water collecting hopper 2. After the neutralization sedimentation treatment device 3 treats the water, most of the water will return to the wet electrostatic precipitator 1 through the return pipe 4 for reuse, and a small amount of water will flow into the coal-containing wastewater treatment system 8 through the second external drainage pipe 7 of the drainage pipe 5. In addition, a small amount of water with dust particles will be discharged through the first external drainage pipe 6. The water treated by the coal-containing wastewater treatment system 8 will flow into the wet electrostatic precipitator 1 through the return water pipe 9 for reuse, thereby minimizing the amount of water discharged outside the wet electrostatic precipitator 1.

[0046] The wet electrostatic precipitator water-saving equipment disclosed in this embodiment further treats the water to be discharged due to the addition of a coal-containing wastewater treatment system 8, thereby realizing secondary recovery and reuse of the water. As a result, the wet electrostatic precipitator water-saving equipment has the beneficial effects of greatly reducing the amount of water discharged from the wet electrostatic precipitator 1, alleviating the adverse effects on the water environment around the power plant, saving the amount of fresh water replenishment and saving water resources.

[0047] See also Figure 1 A plurality of dust collecting electrodes 11 are arranged on both sides of the upper part of the water collecting hopper 2. The plurality of dust collecting electrodes 11 are parallel to each other and spaced apart. The plurality of dust collecting electrodes 11 can capture dust particles driven by the electric field force, and then a continuous water film is formed by spraying water to the plurality of dust collecting electrodes 11. The flowing water flushes the captured dust particles into the hopper and is discharged with the water.

[0048] A plurality of nozzles 12 are provided at the top of the plurality of dust collecting electrodes 11, and the plurality of nozzles 12 correspond to the gaps between the plurality of dust collecting electrodes 11. The plurality of nozzles 12 can spray water mist toward the discharge electrode and the corona zone. The water mist is charged in the strong corona field formed by the thorn electrode and then split and further atomized. Here, the electric field force, the collision interception, adsorption and condensation of the charged water mist jointly capture the dust particles.

[0049] One end of the return pipe 4 is connected to the neutralization sedimentation treatment device 3, and the other end of the return pipe 4 is connected to a plurality of nozzles 12. When the water discharged from the water collecting ash hopper 2 is processed by the neutralization sedimentation treatment device 3, most of it will be returned to the plurality of nozzles 12 through the return pipe 4 for recycling and reuse as flushing water for the wet electrostatic precipitator 1, which is beneficial to saving the amount of fresh water replenishment and, at the same time, saving water resources.

[0050] See also Figure 1 An alkali storage tank 13 is provided at the lower part of the water-collecting ash hopper 2, and the alkali storage tank 13 is connected to the water-collecting ash hopper 2 through a pipeline. Since the water in the water-collecting ash hopper 2 contains not only dust particles but also acidic corrosion, it is necessary to discharge alkaline substances through the alkali storage tank 13 and mix them with the acidic water discharged from the water-collecting ash hopper 2 to achieve acid-base neutralization. The acid-base neutralized water is then discharged into the drainage box 14, which effectively avoids acidic water from corroding the equipment and ensures the service life of the equipment.

[0051] A drainage box 14 is also provided at the lower part of the water collecting ash hopper 2. The water inlet of the drainage box 14 is connected to the water collecting ash hopper 2 and the alkali storage tank 13 through a pipeline. The drainage box 14 has the function of neutralizing and settling, which is beneficial to the treatment of water discharged from the water collecting ash hopper 2.

[0052] The drainage box 14 has a first water outlet 15 and a second water outlet 16. The first water outlet 15 is provided with a circulating water tank 17. The water inlet of the circulating water tank 17 is connected to the first water outlet 15. One end of the return pipe 4 is connected to the water outlet of the circulating water tank 17, and the other end of the return pipe 4 is connected to a plurality of nozzles 12. One end of the drainage pipe 5 is connected to the second water outlet 16. After the water in the drainage box 14 is treated, most of the water will be discharged into the circulating water tank 17 through the first water outlet 15 and the water inlet of the circulating water tank 17 for treatment. The water treated in the circulating water tank 17 will be returned to the wet electrostatic precipitator 1 through the return pipe 4 for reuse and flushing, which greatly reduces the amount of water discharged outside the wet electrostatic precipitator 1 and effectively reduces the adverse effects on the water environment around the power plant. At the same time, it saves the amount of fresh water replenishment and water resources. A small amount of water mixed with dust particles is discharged through the second water outlet 16 and the drainage pipe 5, thereby improving the water quality of most of the reused water to maintain the normal and stable operation of the equipment.

[0053] See also Figure 1 A replenishment water tank 18 is provided between the return water pipeline 9 and the plurality of nozzles 12. One end of the return water pipeline 9 close to the replenishment water tank 18 is connected to the water inlet of the replenishment water tank 18. A replenishment water pipe 19 is provided between the replenishment water tank 18 and the plurality of nozzles 12. Both ends of the replenishment water pipe 19 are respectively connected to the plurality of nozzles 12 and the water outlet of the replenishment water tank 18. The water mixed with dust particles is discharged from the drainage pipeline 5 into the coal-containing wastewater treatment system 8 for further treatment. The treated water flows into the replenishment water tank through the return water pipeline 9. 18. The water in the make-up water tank 18 flows into a number of nozzles 12 through the make-up water pipe 19 for reuse and flushing. Here, the water discharged from the drainage pipe 5 is further processed and recycled to minimize the external discharge volume of the wet electrostatic precipitator 1. After flocculation and sedimentation in the coal-containing wastewater treatment system 8, the solid suspended matter particle content in the wastewater is reduced to 200 mg / l (meeting the reuse requirement of flushing water of the wet electrostatic precipitator 1), and then pumped to the make-up water tank 18 by pump 22 for reuse as flushing water.

[0054] The supply water tank 18 is connected to a supply water pipe 20, which has a supply water valve 21. The supply water pipe 20 can replenish fresh water to the supply water tank 18 in time. Because the equipment will still lose some water after long-term operation, the supply water pipe 20 can maintain water balance, and the supply water valve 21 can control the time and amount of fresh water replenishment.

[0055] The supply water pipe 19, the drainage pipe 5 and the return pipe 4 are all provided with a pump 22 and a first switch 23; the return water pipe 9 and the alkali storage tank 13 are provided with a second switch 24. The water in the supply water pipe 19, the drainage pipe 5 and the return pipe 4 is powered by the pump 22. The first switch 23 can control the switches of the supply water pipe 19, the drainage pipe 5 and the return pipe 4; and the second switch 24 can control the switches of the return water pipe 9 and the alkali storage tank 13, which is conducive to the normal operation of the equipment.

[0056] See also Figure 1 , the specific use steps of a wet electrostatic precipitator water-saving device in this embodiment are as follows: first, a plurality of nozzles 12 directly spray water mist onto the discharge electrode and the corona zone, and the water mist is charged in the strong corona field formed by the thorn electrode and then splits and further atomizes, where the electric field force, the collision interception, adsorption and condensation of the charged water mist jointly capture the dust particles, and finally the dust particles reach the plurality of dust collecting electrodes 11 driven by the electric field force and are captured; then a continuous water film is formed by spraying water onto the plurality of dust collecting electrodes 11, and the flowing water flushes the captured dust into the water collecting hopper 2, and the water carrying the dust particles is discharged into the drainage box 14 through the water collecting hopper 2, and because the water carrying the dust particles is acidic and corrosive, the alkaline substance discharged through the alkali storage tank 13 is mixed with the water carrying the dust particles and flows into the drainage box 14 After the acid-base neutralization reaction is carried out and the water is treated in the drainage tank 14, most of the water will flow into the circulating water tank 17, and the water in the circulating water tank 17 will be returned to the several nozzles 12 for reuse through the pump 22 on the return pipe 4, and a small amount of water will flow into the coal-containing wastewater treatment system 8 through the second external drainage pipe 7 of the drainage pipe 5, and another small amount of water with dust particles will be discharged through the first external drainage pipe 6. The water treated by the coal-containing wastewater treatment system 8 will flow into the supply water tank 18 through the return water pipe 9, and the water in the supply water tank 18 will be transported to the several nozzles 12 for reuse through the pump 22 on the supply water pipe 19, thereby minimizing the amount of water discharged from the wet electrostatic precipitator 1. A small amount of fresh water still needs to be added during the long-term operation of the entire system, which can be achieved by replenishing water to the supply water tank 18 through the supply water pipe 20.

[0057] See also Figure 1In this embodiment, after adopting this technology, it is estimated that the wet electrostatic precipitator 1 equipped with the seawater flue gas desulfurization device of the thermal power unit can reduce the external drainage of the wet electrostatic precipitator 1 by a considerable amount each year, and save an equal amount of fresh water resources; taking a seawater desulfurization device of a 660MW unit as an example, based on an annual utilization hour of 4000h, the external drainage can be reduced by 40,000 tons each year, and 40,000 tons of fresh water resources can be saved at the same time.

[0058] See also Figure 1 In this embodiment, taking a 660MW-class seawater desulfurization device as an example, there is no need to continuously discharge water when the unit is at full load; it only needs to discharge water continuously for 3 hours per week through the first external drainage pipe 6, and the total drainage volume is about 30t, which is equivalent to 0.2t / h in terms of hourly continuous discharge volume; the flocculation and sedimentation capacity of the coal-containing wastewater treatment system 8 is fully utilized, and the solid suspended matter particles in the external drainage of the wet electrostatic precipitator 1 are removed and returned to the process water system of the wet electrostatic precipitator 1 for reuse; at the same time, the amount of fresh water replenishment is saved, saving water resources; the external drainage volume of the wet electrostatic precipitator 1 is greatly reduced, reducing the adverse effects on the water environment around the power plant.

[0059] The above description is only the preferred embodiment of the utility model, and is not intended to limit the utility model. For those skilled in the art, the utility model can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the utility model shall be included in the protection scope of the utility model.

Claims

1. A wet electrostatic precipitator water-saving device, characterized in that: comprising a wet electrostatic precipitator (1); The wet electrostatic precipitator (1) has a water collecting hopper (2), a neutralization and sedimentation treatment device (3) is provided at the lower part of the water collecting hopper (2), and the neutralization and sedimentation treatment device (3) is connected to the water collecting hopper (2) through a pipeline; The neutralization precipitation treatment device (3) has a return pipeline (4), and the two ends of the return pipeline (4) are respectively connected to the neutralization precipitation treatment device (3) and the wet electrostatic precipitator (1); A drainage pipeline (5) is provided at the tail end of the neutralization sedimentation treatment device (3), and one end of the drainage pipeline (5) is connected to the neutralization sedimentation treatment device (3); The drainage pipeline (5) comprises a first external drainage pipe (6) and a second external drainage pipe (7); a coal-containing wastewater treatment system (8) is provided at one end of the second external drainage pipe (7) away from the neutralization sedimentation treatment device (3); the second external drainage pipe (7) is connected to the coal-containing wastewater treatment system (8); a return water pipeline (9) is provided at the tail end of the coal-containing wastewater treatment system (8) after treatment; the two ends of the return water pipeline (9) are respectively connected to the tail end of the coal-containing wastewater treatment system (8) and the wet electrostatic precipitator (1).

2. A wet electrostatic precipitator water-saving device according to claim 1, characterized in that: A plurality of dust collecting electrodes (11) are arranged on both sides of the upper part of the water collecting hopper (2), and the plurality of dust collecting electrodes (11) are parallel to each other and distributed at intervals.

3. A wet electrostatic precipitator water-saving device according to claim 2, characterized in that: A plurality of nozzles (12) are provided at the top ends of the plurality of dust collecting electrodes (11), and the plurality of nozzles (12) correspond to the gaps between the plurality of dust collecting electrodes (11).

4. A wet electrostatic precipitator water-saving device according to claim 3, characterized in that: One end of the return pipeline (4) is connected to the neutralization precipitation treatment device (3), and the other end of the return pipeline (4) is connected to a plurality of the nozzles (12).

5. A wet electrostatic precipitator water-saving device according to claim 3, characterized in that: An alkali storage tank (13) is provided at the lower part of the water collecting ash hopper (2), and the alkali storage tank (13) is connected to the water collecting ash hopper (2) through a pipeline.

6. A wet electrostatic precipitator water-saving device according to claim 5, characterized in that: A drainage box (14) is also provided at the lower part of the water collecting ash hopper (2), and the water inlet of the drainage box (14) is connected to the water collecting ash hopper (2) and the alkali storage tank (13) through a pipeline.

7. A wet electrostatic precipitator water-saving device according to claim 6, characterized in that: The drainage box (14) has a first water outlet (15) and a second water outlet (16); the first water outlet (15) is provided with a circulating water tank (17); the water inlet of the circulating water tank (17) is connected to the first water outlet (15); one end of the return pipe (4) is connected to the water outlet of the circulating water tank (17); and the other end of the return pipe (4) is connected to a plurality of the nozzles (12); One end of the drainage pipeline (5) is connected to the second water outlet (16).

8. A wet electrostatic precipitator water-saving device according to claim 5, characterized in that: A replenishing water tank (18) is provided between the return water pipeline (9) and the plurality of nozzles (12); one end of the return water pipeline (9) close to the replenishing water tank (18) is connected to the water inlet of the replenishing water tank (18); a replenishing water pipe (19) is provided between the replenishing water tank (18) and the plurality of nozzles (12); two ends of the replenishing water pipe (19) are respectively connected to the water outlets of the plurality of nozzles (12) and the replenishing water tank (18).

9. A wet electrostatic precipitator water-saving device according to claim 8, characterized in that: The replenishing water tank (18) is connected to a replenishing water pipe (20), and the replenishing water pipe (20) is provided with a replenishing water valve (21).

10. A wet electrostatic precipitator water-saving device according to claim 9, characterized in that: The supply water pipe (19), the drainage pipe (5) and the return pipe (4) are each provided with a pump (22) and a first switch (23); A second switch (24) is provided on the pipeline of the water return pipeline (9) and the alkali storage tank (13).

Images