Vertical wet electrostatic precipitator

Abstract

The present invention discloses a vertical wet electrostatic precipitator, comprising a plurality of dust collecting electrodes and cathode wires, wherein the dust collecting electrode is a sieve tube with a plurality of through holes on the tube wall, the cathode wire is arranged in the dust collecting electrode, a sealing plate is arranged on the top of the sieve tube, the sealing plate connects the sieve tubes, the sealing plate shields the gap area between the sieve tubes, and a nozzle for spraying water to the outer wall of the sieve tube is arranged in the gap area. The present invention can be flushed without power off, the dust collecting space and the airflow space are separated, the secondary dust problem on the dust collecting electrode is solved, and the dust removal efficiency is improved.

Description

Technical Field

[0001] The invention relates to an electrostatic precipitator, in particular to a vertical wet electrostatic precipitator. Background Art

[0002] The internal airflow of a vertical electrostatic precipitator is usually from bottom to top, and the dust needs to fall downward into the ash hopper to achieve final separation. The gas flow direction is not conducive to the capture and separation of the dust, and may even cause the dust driven into the dust collecting electrode to be raised again.

[0003] With wet electrostatic dust removal, spraying water on the dust collecting electrode (anode) to form a water film can reduce the problem of secondary dust, and can rely on the water film to promote dust removal. However, the cylindrical anode tube is long, and it is impossible to set up flushing inside it, so only end flushing can be used. In addition, the cathode wire is also set in the anode tube. The electric field needs to be powered off during end flushing. At that time, the dust collector loses its electrostatic dust removal ability, and the efficiency of the dust collector is greatly reduced during flushing; intermittent flushing often takes several hours (4h~24h) each time. During the period of stopping flushing, as the flue gas continues to flow, the flue gas gradually carries away the water film on the dust collecting electrode. The dust collecting electrode is often dried up before the next flushing and cannot be cleaned by water film, which will further affect the efficiency of the dust collector. Summary of the invention

[0004] In view of the above-mentioned defects of the prior art, the task of the present invention is to provide a vertical wet electrostatic precipitator to solve the problem of secondary dust on the dust collecting electrodes, ensure a continuous water film on the dust collecting electrodes, and improve the dust removal efficiency.

[0005] The technical solution of the present invention is as follows: a vertical wet electrostatic precipitator, comprising a plurality of dust collecting electrodes and cathode wires, the dust collecting electrode being a sieve tube with a plurality of through holes on the tube wall, the cathode wire being arranged in the dust collecting electrode, a sealing plate being provided on the top of the sieve tube, the sealing plate connecting each of the sieve tubes, the sealing plate shielding the gap area between each of the sieve tubes, and a nozzle for spraying water toward the outer wall of the sieve tube being provided in the gap area.

[0006] The present invention sets the integrated electrode as a sieve hole tube. As in the prior art, a part of the charged dust loses charge on the inner wall of the sieve hole tube and is adsorbed on the inner wall of the sieve hole tube or falls directly. The other part of the charged dust passes through the through holes in the wall of the sieve hole tube and enters the gap area between the sieve hole tubes and loses charge again and is adsorbed on the outer wall of the sieve hole tube or falls directly. The nozzle sprays water on the outer wall of the sieve hole tube to form a water film to achieve the effect of further adsorbing dust and continuously removing it.

[0007] Furthermore, the cross section of the mesh tube is circular, and the cathode wire is arranged along the axis of the mesh tube. Compared with the hexagonal dust collecting electrode, the cathode wire is at the same distance from the wall of the circular mesh tube, and the electric field strength at each location in the mesh tube is the same. The uniform electric field can increase the average operating voltage, improve the dust charging efficiency and driving speed, and further improve the dust removal efficiency.

[0008] Furthermore, a plurality of nozzles are arranged at intervals along the axial direction of the sieve tube. Arranging a plurality of nozzles at intervals can effectively ensure that the outer wall of the sieve tube is covered with a water film over a long distance to fully absorb dust.

[0009] Furthermore, the sealing plate is a conductive plate, and the sealing plate is electrically connected to each of the sieve tubes, and the sieve tubes constituting the gap area are connected to each other in the circumferential direction of the gap area and are electrically connected. The sieve tubes in the gap area form a "Faraday cage" to shield the electric field outside the gap area, and the dust separated into the gap area is not affected by the electric field force, thereby ensuring the separation effect.

[0010] Furthermore, the cross section of the sieve tube is circular, and the outer walls of adjacent sieve tubes are closely fitted. The closely fitting circular sieve tubes can be arranged as many as possible in the dust collector space, and the gap area is constructed by using the gaps between the circular tubes. Compared with the hexagonal dust collecting electrode, the processing flow of the dust-laden airflow is not much reduced, and at the same time, an area for continuous water spraying is obtained.

[0011] Furthermore, the sieve tubes are arranged in multiple rows, the sieve tubes in adjacent rows are arranged in a staggered manner, and the circumference of the gap area is the tube walls of three adjacent sieve tubes.

[0012] The advantages of the present invention compared with the prior art are:

[0013] Since the sealing plate on the top of the sieve tube shields the gap area between the sieve tubes, the airflow entering the electrostatic precipitator mainly passes through the inside of the sieve tube, there is less airflow in the gap area, and the dust collecting space and the airflow space are separated. Therefore, the dust in the gap area can fall quickly and naturally and is less affected by the airflow; due to the adsorption effect of the water film on the outer wall of the sieve tube and the continuous water spraying of the nozzle and the cathode line separation, the possibility of the adsorbed dust being carried away by the airflow can be reduced; the water sprayed on the outer wall of the sieve tube can also enter the inner wall of the sieve tube through the through holes in the tube wall, forming a water film on the inner wall of the sieve tube, which supplements the water film formed by the intermittent water spraying at the end of the anode tube, thereby improving the ability of the inner wall of the sieve tube to continuously adsorb dust, and generally improving the dust removal efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic diagram of the structure of the vertical wet electrostatic precipitator of Example 1.

[0015] Figure 2 This is a schematic diagram of the dust collecting electrode structure of Example 1.

[0016] Figure 3 This is a schematic plan view of the dust collecting electrode arrangement structure of Example 1.

[0017] Figure 4 This is a schematic diagram of the planar structure of the nozzle arrangement of Example 1.

[0018] Figure 5 It is a three-dimensional schematic diagram of the dust collecting electrode arrangement structure of Example 1.

[0019] Figure 6 Schematic diagram of dust separation and collection by electrode layer.

[0020] Figure 7 This is a schematic diagram of the dust collecting electrode arrangement structure of Example 2.

[0021] Figure 8 This is a schematic diagram of the dust collecting electrode arrangement structure of Example 3. DETAILED DESCRIPTION

[0022] The present invention is further described below in conjunction with examples. It should be understood that these examples are only used to illustrate the present invention and are not used to limit the scope of the present invention. After reading this description, various equivalent modifications to this description by those skilled in the art fall within the scope defined by the claims attached to this application.

[0023] Example 1, please combine Figures 1 to 5 As shown, a vertical wet electrostatic precipitator involved in this embodiment includes a precipitator body 1, the top of the precipitator body 1 is an airflow outlet 2, the bottom of the precipitator body 1 is a water collecting dust collecting hopper 3, and a lateral airflow inlet 4 is opened above the bottom of the precipitator body 1. A spray layer and an electrode layer are arranged between the airflow outlet 2 and the airflow inlet 4 in the precipitator body 1, and the spray layer is located above the electrode layer. The electrode layer mainly includes a dust collecting electrode and a cathode wire 5, and the cathode wire 5 is connected to a high-voltage DC power supply 6. The dust collecting electrode and the outer shell of the precipitator body 1 are grounded. The spray layer is composed of a plurality of spray heads 7 and corresponding water supply pipelines, and the spray layer is used to implement intermittent spraying on the electrode layer.

[0024] In this embodiment, the dust collecting electrode is a sieve tube 8 with a plurality of through holes 8a on the tube wall. The diameter of the through holes can be 2-20 mm. It should also be noted that the through holes 8a in the present invention may not be circular holes. A certain gap is left between the multiple sieve tubes 8, so that an airflow flow area A surrounded by the tube wall of a single sieve tube 8 and a gap area B formed between the multiple sieve tubes 8 are formed in the entire electrode layer. A cathode line 5 is set in the airflow flow area A, that is, in a single sieve tube 8. Generally speaking, the cathode line 5 is set on the axis of the sieve tube 8 so that the electric field in the sieve tube 8 is symmetrically distributed to ensure the dust removal effect.

[0025] A transversely extending sealing plate 9 is connected to the top of the sieve tube 8, and the sealing plate 9 is used to shield the gap area B between each sieve tube 8, that is, the sealing plate 9 is provided with holes corresponding to the sieve tube 8, and the top of the sieve tube 8 is inserted into the hole or the mouth of the sieve tube 8 is directly fixed to the edge of the hole. Therefore, due to the existence of the sealing plate 9, after the dust-laden airflow enters the electrode layer from below, most of the airflow will pass through the airflow flow area A, while the gas flow in the gap area B is small and the airflow is relatively stable.

[0026] The spray head 7 of the spray layer is arranged directly above the sieve tube 8, and is used for spraying at intervals into the sieve tube 8. In the gap area B between the sieve tubes 8, a plurality of nozzles 10 are also arranged, and these nozzles 10 are used for continuous or intermittent spraying to the outer wall of the sieve tube 8 to form a water film. The nozzle 10 can be installed in the central opening of the sealing plate 9 of each gap area B, and because the electrodes of some electrostatic precipitators have a long length, a single gap area B can also be provided with a plurality of nozzles 10, and these nozzles 10 are arranged at intervals in the length direction of the sieve tube 8, such as Figure 1 Please combine Figure 6 As shown, a part of the charged dust C1 in the airflow contacts the inner wall of the sieve tube 8 in the airflow circulation area A, loses electricity and falls, or is adsorbed by the water film on the inner wall surface of the sieve tube 8 (sprayed by the spray head 7 of the spray layer, and sprayed by the nozzle 10 in the gap area B and penetrated from the through hole of the sieve tube 8). After the other part of the charged dust C2 is driven into the inner wall of the sieve tube 8, it will pass through the through hole 8a opened on the sieve tube 8, enter the gap area B, contact the outer wall of the sieve tube 8, lose electricity and fall, or be adsorbed by the water film on the outer wall surface of the sieve tube 8, thereby achieving the effect of combining the inner and outer effects of the sieve tube 8 and improving the dust removal efficiency.

[0027] As a preferred embodiment, in this embodiment, the sieve tubes 8 are all round tubes and are closely arranged side by side in rows. The sieve tubes 8 in adjacent rows are arranged in a staggered manner. That is, a gap area B is formed between every three sieve tubes 8. Figure 3 , Figure 5As shown. In addition, the sealing plate 9 at the top is a conductive plate, and the sealing plate 9 is electrically connected to each sieve tube 8. Since the closely arranged sieve tubes 8 are close to each other, the sieve tubes 8 in the circumferential direction of the gap area B are also directly connected, thereby forming a "Faraday cage" to shield the electric field outside the gap area, and the dust separated into the gap area B is not affected by the electric field force. It can be understood that in some embodiments, the sieve tubes 8 may not be closely arranged. In order to form a "Faraday cage", a conductive plate can be added between the tube walls of the sieve tubes 8 to close and connect the gap area B in the circumferential direction.

[0028] Example 2, please combine Figure 7 As shown, in this embodiment, the circular sieve tubes 8 are arranged in a row and column matrix, and the remaining structure is the same as that of Example 1. Compared with Example 1, this embodiment only adjusts the size of the gap area B, so it is suitable for the sieve tubes 8 with a smaller tube diameter, so that the gap area B has enough space to arrange the nozzle 10.

[0029] Example 3, please combine Figure 8 As shown, in this embodiment, the cross section of the sieve tube 8 is hexagonal, the sieve tubes 8 are closely arranged, and six sieve tubes 8 are arranged around a gap area B, and the rest of the structure is the same as that of embodiment 1. This structure can effectively expand the space of the gap area B, increase the arrangement density of the sieve tubes 8, and is also suitable for sieve tubes 8 with smaller diameters.

Claims

1. A vertical wet electrostatic precipitator, characterized in that: It includes a plurality of dust collecting electrodes and cathode wires. The dust collecting electrode is a sieve tube with a plurality of through holes on the tube wall. The cathode wire is arranged in the dust collecting electrode. A sealing plate is provided on the top of the sieve tube. The sealing plate connects each of the sieve tubes and shields the gap area between each of the sieve tubes. A nozzle for spraying water toward the outer wall of the sieve tube is provided in the gap area.

2. The vertical wet electrostatic precipitator according to claim 1, characterized in that: The cross section of the sieve tube is circular, and the cathode wire is arranged along the axis of the sieve tube.

3. The vertical wet electrostatic precipitator according to claim 1, characterized in that: A plurality of nozzles are arranged at intervals along the axial direction of the sieve tube.

4. The vertical wet electrostatic precipitator according to claim 1, characterized in that: The sealing plate is a conductive plate, and is electrically connected to each of the sieve tubes. The sieve tubes forming the gap area are connected to each other in the circumferential direction of the gap area and are electrically connected.

5. The vertical wet electrostatic precipitator according to claim 1, characterized in that: The cross section of the sieve tube is circular, and the outer walls of adjacent sieve tubes are tightly fitted.

6. The vertical wet electrostatic precipitator according to claim 5, characterized in that: The sieve tubes are arranged in multiple rows, and the sieve tubes in adjacent rows are arranged in a staggered manner. The circumference of the gap area is the tube walls of three adjacent sieve tubes.

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