A wet electrostatic precipitator having a cleanable cathode and a cleaning method

Abstract

The application discloses a wet electrostatic precipitator with cleanable cathode and a cleaning method thereof, and relates to the technical field of wet electrostatic precipitation. In order to overcome the defects of the existing fixed cathode line dust accumulation causing corona closure and large water consumption of spray dust removal, the application comprises a shell, a cathode rotating driving mechanism and a dust accumulation scraping mechanism. A plurality of hexagonal anode tubes arranged in a honeycomb array are arranged in the shell, and a cathode wire is arranged in each anode tube. An upper roller is mounted on an upper rotating insulating shaft, and a lower roller is mounted on a lower conductive shaft. The cathode wire passes through the upper roller and the lower roller to form a ring and is driven to circulate by a driving motor. A dust removal shovel is fixed to the bottom of the anode tube and scrapes the surface of the cathode wire. During dust removal, the cathode wire continuously passes through the fixed dust removal shovel, and the dust, oil sludge and dirt adhered to the surface are continuously scraped off, so that the online mechanical cleaning of the cathode dust accumulation is realized. The application does not need large-flow flushing water and does not interrupt the dust removal working condition, and can long-term maintain the cathode discharge performance and the dust removal efficiency.

Description

Technical Field

[0001] This invention relates to the field of wet electrostatic precipitator technology, specifically to a wet electrostatic precipitator with a cleanable cathode and a cleaning method thereof. Background Technology

[0002] After being cooled by spraying, the flue gas exiting the absorption towers in industries such as coal combustion, chemical processing, and coking contains a large amount of condensate droplets, viscous oil mist, and ultrafine dust. To meet increasingly stringent emission requirements, wet electrostatic precipitators are needed for deep purification of the flue gas. Wet electrostatic precipitators rely on corona discharge on the cathode wires to charge dust and droplets. The charged particles migrate towards the honeycomb anode tube wall under the action of the electric field and are captured, thereby achieving flue gas purification.

[0003] The cathode wires of existing conventional wet electrostatic precipitators adopt a fixed vertical suspension structure, which has the following defects during long-term operation: First, cathode ash accumulation causes corona shutdown. Sticky dust and oil mist in the flue gas continuously adhere to the surface of the cathode wire, and long-term accumulation forms ash covering the electrode wire, which greatly reduces the curvature of the cathode discharge tip, causing the corona discharge intensity to decrease sharply, the dust charging capacity to drop, resulting in excessive emissions of particulate matter and mist droplets at the outlet, as well as faults such as low electric field current and frequent flashover tripping.

[0004] Secondly, the traditional dust removal method has significant drawbacks. Traditional dust removal relies on spraying water to flush the cathode wires, which has problems such as high water consumption, easy scaling and clogging of spray nozzles, and uneven distribution of flushing water flow, and local dust accumulation on the cathode cannot be completely removed. If manual cleaning is carried out after shutdown, the entire set of equipment must be shut down offline, which greatly shortens the continuous operation time of the unit and results in high operation and maintenance costs.

[0005] Third, there are potential insulation safety hazards. Continuous spraying and rinsing will increase the risk of moisture-induced creepage and short circuits in the insulating components, requiring the addition of auxiliary equipment such as insulation blowing and heating, which makes the equipment structure more complex.

[0006] Currently, the industry lacks a cathode cleaning structure that can remove cathode ash online without requiring a large amount of flushing water and without interrupting the dust removal process, making it difficult to balance the long-term stable operation and low maintenance costs of wet electrostatic precipitators. Summary of the Invention

[0007] To address the shortcomings of existing wet electrostatic precipitators, such as the fixed vertical suspension structure of the cathode wire leading to "corona sealing" due to cathode ash accumulation during long-term operation, the high water consumption and poor cleaning effect of traditional spray cleaning, and the insulation safety hazards caused by continuous spraying, this invention provides a wet electrostatic precipitator with a cleanable cathode and its cleaning method. This method enables online mechanical scraping of cathode ash without the need for large amounts of flushing water, without interrupting the dust removal process, and maintains stable dust removal efficiency over a long period.

[0008] To address the aforementioned technical problems, the present invention provides a wet electrostatic precipitator with a cleanable cathode, comprising: The housing contains multiple hexagonal anode tubes arranged in a honeycomb array, and each anode tube contains a cathode wire. A cathode rotation drive mechanism includes an upper roller and a lower roller. The upper roller is mounted on an upper rotating insulating shaft, which is connected to the housing and supported at the upper end of the anode tube. The lower roller is mounted on a lower conductive shaft, which is connected to the housing and supported at the lower end of the anode tube. The cathode wire passes around the upper roller and the lower roller in sequence to form a ring. The upper rotating insulating shaft is driven to rotate by a drive motor located outside the housing. The upper rotating insulating shaft drives the upper roller to rotate and drives the cathode wire and the lower roller to move synchronously. The dust removal mechanism includes a dust removal shovel, which is fixed to the bottom of the anode tube, and the edge of the dust removal shovel scrapes against the surface of the cathode wire.

[0009] Furthermore, the dust removal shovel is conical, and a wire-passing hole is provided in the center of the dust removal shovel. The cathode wire passes through the wire-passing hole, and there is a clearance fit between the wire-passing hole and the cathode wire. The edge of the wire-passing hole scrapes against the surface of the cathode wire, and the conical surface of the dust removal shovel points in the opposite direction to the movement direction of the cathode wire at that point.

[0010] Furthermore, the dust removal shovel is a double-pyramidal shape, and a wire-passing hole is provided in the center of the dust removal shovel. The cathode wire passes through the wire-passing hole, and there is a clearance fit between the wire-passing hole and the cathode wire. The edge of the wire-passing hole makes scraping contact with the surface of the cathode wire.

[0011] Furthermore, the conical surface of the dust removal shovel is rounded and blunted.

[0012] Furthermore, the dust removal shovel is made of wear-resistant fiberglass or 316L stainless steel.

[0013] Furthermore, the upper roller is fixedly connected to the upper rotating insulating shaft, the lower roller is fixedly connected to the lower conductive shaft, and the upper rotating insulating shaft and the lower conductive shaft are respectively rotatably connected to the housing.

[0014] Furthermore, the upper rotating insulating shaft is made of polytetrafluoroethylene insulating material, and the lower roller is a conductive and corrosion-resistant roller.

[0015] Furthermore, the upper rollers corresponding to each row of anode tubes are mounted on the same upper rotating insulating shaft, and the lower rollers corresponding to the upper rollers are mounted on the same lower conductive shaft.

[0016] Furthermore, one end of the upper rotating insulating shaft extends out of the housing and is connected to a transmission gear, and the drive motor drives the upper rotating insulating shaft through the drive gear meshing with the transmission gear.

[0017] Furthermore, both the transmission gear and the drive gear are bevel gears, and multiple drive gears are mounted on the same drive shaft, which is connected to the drive motor.

[0018] A cleaning method, employing the aforementioned wet electrostatic precipitator with a cleanable cathode, includes the following steps: S10. Flue gas dust removal: Flue gas is introduced into the anode tube from bottom to top. Washing water is sprayed above the anode tube. The cathode wire is connected to a high-voltage direct current to generate a corona electric field, which purifies the flue gas passing through the anode tube. S20, Cathode cleaning: During the flue gas dust removal process, the drive motor drives the upper rotating insulating shaft to rotate, the upper rotating insulating shaft drives the upper roller to rotate, and drives the cathode wire and the lower roller to move synchronously. The cathode wire continuously passes through the fixed dust removal shovel, and the dust removal shovel scrapes and contacts the surface of the cathode wire to remove the accumulated dust on the surface of the cathode wire. S30. Waste Discharge: The scraped-off waste is flushed out downwards by its own weight and the flushing water sprayed above the anode tube.

[0019] The beneficial effects of this invention are: 1. Relying on the drive motor outside the shell, the cathode rotates in conjunction with the dust scraper to mechanically scrape off ash. The equipment can continuously remove the ash accumulated on the cathode when it is under load. The cathode always maintains a clean discharge surface, which prevents corona blockage caused by ash and dirt. It can maintain the efficiency of mist and dust removal in a long-term stable manner and avoid excessive emissions at the outlet. 2. Abandoning the traditional high-pressure water flushing solution for cathodes, significantly reducing cathode flushing water consumption and eliminating problems such as nozzle clogging and pipe scaling; eliminating the need for insulated hot air purging and electric heating moisture-proof devices, reducing auxiliary equipment energy consumption and infrastructure investment; 3. All transmission components such as transmission gears and drive motors are arranged on the outside of the dust collector shell. The upper rotating insulating shaft isolates the high-voltage electric field from the transmission components, eliminating the safety hazards of leakage, creepage, and short circuit. Moreover, maintenance and repair do not require entering the high-humidity, high-voltage tower. 4. The overall modular structure can be directly adapted to the renovation of existing hexagonal honeycomb wet scrubbers. The lower rollers and dust removal shovels are corrosion-resistant and wear-resistant, and have a long service life under long-term wet acidic flue gas conditions. There is no need to modify the original anode tubes and high-voltage power supply system, resulting in low renovation costs and a wide range of compatibility. 5. No need for regular shutdowns for manual cleaning of cathode ash accumulation, significantly reducing unit downtime for maintenance, especially suitable for continuous production conditions in power plants and chemical plants, significantly improving the operational stability and economic benefits of the entire flue gas treatment system. Attached Figure Description

[0020] Figure 1 This is a front view of the internal structure of the anode tube of the present invention; Figure 2 This is a side view of the internal structure of the anode tube of the present invention; Figure 3 This is a top view of the present invention.

[0021] Explanation of the labels in the diagram: 1. Lower roller; 2. Cathode wire; 3. Dust removal shovel; 4. Anode tube; 5. Lower conductive shaft; 6. Upper rotating insulating shaft; 7. Transmission gear; 8. Upper roller. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0023] The wet electrostatic precipitator with a cleanable cathode of the present invention mainly includes a shell, multiple hexagonal anode tubes 4, a cathode wire 2, a cathode rotation drive mechanism, and a dust scraping mechanism, wherein the shell and anode tubes 4 are configured in the existing design.

[0024] Specifically, the casing serves as the main load-bearing structure of the dust collector, and its internal space accommodates the anode tube 4, cathode wire 2, and various drive and scraping components. (Refer to...) Figure 3 As shown, multiple hexagonal anode tubes 4 are arranged in a honeycomb array within the shell, with adjacent anode tubes 4 sharing a common wall, forming a compact and dense honeycomb structure. Using anode tubes 4 with regular hexagonal cross-sections arranged in a honeycomb array fully utilizes the internal cross-sectional space of the shell, arranging as many dust collection channels as possible within the limited inner diameter of the shell, increasing the dust collection area per unit volume, and improving dust removal efficiency. Simultaneously, the regular structure and uniform stress of each anode tube 4 in the honeycomb array contribute to the stability of the overall structure. The anode tubes 4 typically employ several sizes with inscribed circle diameters ranging from 250 mm to 400 mm, with the length determined by the shell height. Materials can include conductive and corrosion-resistant lead-antimony alloys, fiberglass, or conductive resin composite materials. The inner surface of the tube wall is kept smooth to facilitate uniform water film spreading and flushing.

[0025] Reference Figure 1 and Figure 2As shown, a cathode wire 2 is threaded through the center of each anode tube 4, forming an annular flue gas charging and dust removal channel between the inner wall of the anode tube 4 and the cathode wire 2. The flue gas flows through this channel from bottom to top, and is charged and collected under the influence of the corona electric field generated by the cathode wire 2. The cathode wire 2 is wound around the outer circumference of the upper roller 8 and the lower roller 1 of the cathode rotation drive mechanism, forming an annular circuit that can circulate between the two rollers; the line connecting the center of the upper roller 8 and the center of the lower roller 1 coincides with the central axis of the anode tube 4, and the position of each cathode wire 2 segment inside the anode tube 4 is constrained by the upper and lower rollers, preventing deviation, jumping, or collision with the inner wall of the anode tube 4 during operation.

[0026] The cathode rotation drive mechanism includes an upper roller 8 and a lower roller 1. The upper roller 8 is mounted on an upper rotating insulating shaft 6, which is connected to the housing and supported at the upper end of the anode tube 4. The lower roller 1 is mounted on a lower conductive shaft 5, which is connected to the housing and supported at the lower end of the anode tube 4. The cathode wire 2 passes around the upper roller 8 and the lower roller 1 in sequence to form a ring. That is, the upper end of the cathode wire 2 is wrapped around the outer circumference of the upper roller 8, and the lower end is wrapped around the outer circumference of the lower roller 1, so that the cathode wire 2 is tensioned between the upper roller 8 and the lower roller 1, and its middle part vertically passes through the corresponding anode tube 4. The surfaces of the upper roller 8 and the lower roller 1 are provided with annular grooves adapted to the cathode wire 2. The width of the grooves is slightly larger than the diameter of the cathode wire 2, so that the cathode wire 2 can be stably embedded in the grooves and rotate synchronously with the rollers, avoiding slippage and dislodging.

[0027] The upper rotating insulating shaft 6 is driven to rotate by a drive motor. When the drive motor rotates, it drives the upper rotating insulating shaft 6 and the upper roller 8 fixedly installed on it to rotate. The upper roller 8 drives the cathode wire 2 to circulate along the annular path by the friction between the wire groove and the cathode wire 2. The cathode wire 2 then drives the lower roller 1 to rotate synchronously. As a result, the cathode wire 2 segment that runs through each anode tube 4 moves continuously along its length and generates continuous relative sliding with the fixed dust removal shovel 3, providing power for online dust removal.

[0028] The dust removal mechanism includes a dust scraper 3, which is fixed to the bottom of the anode tube 4, and the edge of the dust scraper 3 scrapes against the surface of the cathode wire 2. When the cathode wire 2 moves in a cycle, the surface of the cathode wire 2 continuously slides over the edge of the dust scraper 3, and the dust scraper 3 continuously scrapes off the dust, sludge, mist droplets and other contaminants adhering to the surface of the cathode wire 2. The scraped-off contaminants are flushed down and discharged with the water film on the inner wall of the anode tube 4.

[0029] It should be noted that the aforementioned shell is a load-bearing structure commonly used in wet electrostatic precipitators in the prior art. Its shape, internal layout, pressure rating, and corrosion protection structure all follow mature industry solutions. This invention has not made any improvements to its structural form. Therefore, the specific structure of the shell is not shown separately in the accompanying drawings of this invention.

[0030] Reference Figure 1 and Figure 2 As shown, this is an embodiment of the present invention. In this embodiment, the dust removal shovel 3 is conical, with a wire-passing hole at its center. The cathode wire 2 passes through the wire-passing hole, and there is a clearance fit between the wire-passing hole and the cathode wire 2. The edge of the wire-passing hole makes scraping contact with the surface of the cathode wire 2. The conical surface of the dust removal shovel 3 points in the opposite direction to the rotation direction of the cathode wire 2. That is, the conical tip of the dust removal shovel 3 is positioned facing the incoming direction of the cathode wire 2, so that the dirt adhering to the surface of the cathode wire 2 is gradually peeled off by the conical surface and guided outward during the movement, rather than being pressed into the surface of the cathode wire 2. This improves the scraping efficiency and reduces the wear of the dust removal shovel 3 on the discharge surface of the cathode wire 2, which is beneficial for maintaining the discharge performance of the cathode wire 2 over a long period of time. The cone angle of the conical dust removal shovel 3 is preferably between 30° and 45°. If the cone angle is too small, the scraping resistance will be too large; if the cone angle is too large, the slag guidance will be insufficient. The diameter of the through hole and the diameter of the cathode wire 2 are kept in a proper clearance fit. The clearance is usually controlled between three percent and eight percent of the wire diameter. This ensures that the cathode wire 2 does not get stuck when passing through, and also ensures that the hole wall forms a continuous scraping contact with the surface of the cathode wire 2.

[0031] Furthermore, in another embodiment of the present invention, the dust removal shovel 3 is a double-pyramidal shape, and a wire-passing hole is also provided in the center of the dust removal shovel 3. The cathode wire 2 passes through the wire-passing hole, and there is a clearance fit between the wire-passing hole and the cathode wire 2. The edge of the wire-passing hole makes scraping contact with the surface of the cathode wire 2. The double-pyramidal structure makes both ends of the dust removal shovel 3 tapered in a conical shape along the direction of movement of the cathode wire 2. No matter which direction the cathode wire 2 moves, the dust removal shovel 3 can scrape the surface of the cathode wire 2 with the receiving cone. It is suitable for the working conditions of bidirectional circulation or reciprocating motion of the cathode wire 2, and it also makes it easy to install the dust removal shovel 3 without distinguishing the direction, thus improving the assembly convenience. The two cones of the double-pyramidal dust removal shovel 3 can be symmetrically arranged, and the two cone surfaces together form a closed scraping band around the cathode wire 2. The scraped slag falls down along the cone surface to the bottom of the dust collector.

[0032] Regardless of whether a conical or double-conical dust scraper 3 is used, the conical surface of the dust scraper 3 is rounded and blunted, meaning the edge of the conical surface is smoothly transitioned to avoid sharp edges scratching the discharge tip surface of the cathode wire 2, thus ensuring the dust removal effect while protecting the integrity of the discharge surface of the cathode wire 2. The dust scraper 3 is fixed to the support at the bottom of the anode tube 4 by a scraper seat. The support is rigidly connected to the outer wall of the anode tube 4 or the inner wall of the shell, ensuring that the dust scraper 3 does not shake, deflect, or move axially during the cyclic movement of the cathode wire 2, thus ensuring a stable scraping position.

[0033] The dust scraper 3 is made of wear-resistant fiberglass or 316L stainless steel. Wear-resistant fiberglass combines excellent wear resistance, corrosion resistance, and insulation, preventing unintended electrical connections between the dust scraper 3 and the cathode wire 2. 316L stainless steel has excellent acid, moisture, and corrosion resistance, making it suitable for high-humidity, acidic, and oily flue gas conditions. Both materials ensure that the dust scraper 3 maintains stable dust removal capabilities during long-term operation, extending its service life.

[0034] Reference Figure 2 As shown, the upper roller 8 is fixedly connected to the upper rotating insulating shaft 6, and the lower roller 1 is fixedly connected to the lower conductive shaft 5. The upper rotating insulating shaft 6 and the lower conductive shaft 5 are rotatably connected to the housing. The upper rotating insulating shaft 6 serves as the rotating support and power input shaft for the upper roller 8, and also provides electrical insulation, isolating the high-voltage electricity carried by the cathode wire 2 from the external transmission mechanism. The lower conductive shaft 5 serves as the rotating support for the lower roller 1 and is rotatably connected to the housing, ensuring that the lower end of the cathode wire 2 has a stable rotating support, so that the cathode wire 2 remains taut and does not wobble during cyclic movement. Insulating sleeves and mechanical bearings are respectively installed between the upper rotating insulating shaft 6 and the housing, and between the lower conductive shaft 5 and the housing. The insulating sleeves are located on the inner side for electrical isolation, and the mechanical bearings are located on the outer side for bearing radial and axial loads. The two work together to ensure both flexible rotation and reliable insulation.

[0035] The upper rotating insulated shaft 6 is made of polytetrafluoroethylene (PTFE) insulation material. PTFE has excellent insulation, moisture resistance, and acid and alkali corrosion resistance, enabling it to reliably isolate the cathode high-voltage electricity from the external transmission mechanism in high-humidity, acidic flue gas environments, preventing leakage, creepage, and short circuits, and ensuring safe equipment operation. The axial length of the PTFE insulated section is typically determined based on the working voltage of the cathode wire 2 and the humid environment inside the casing to ensure sufficient creepage distance. The lower roller 1 is made of conductive and corrosion-resistant material, allowing the cathode wire 2 to connect to the external high-voltage transformer via the lower conductive shaft 5, enabling the connection of high-voltage DC power. It also provides corrosion resistance, adapting to long-term operation in high-humidity, acidic flue gas environments.

[0036] Reference Figure 3 As shown, the upper rollers 8 corresponding to each row of anode tubes 4 are mounted on the same upper rotating insulating shaft 6, and the lower rollers 1 corresponding to the upper rollers 8 are mounted on the same lower conductive shaft 5. That is, one upper rotating insulating shaft 6 can simultaneously drive multiple cathode wires 2 in a whole row of anode tubes 4, and one lower conductive shaft 5 simultaneously supports multiple cathode wires 2 in that row. Through this arrangement of unified driving and unified support for the whole row, the synchronous cyclic movement of the cathode wires 2 in the whole row or even the entire cellular array can be achieved with fewer driving components, simplifying the transmission structure, reducing driving energy consumption and equipment costs, and ensuring the synchronicity of the movement of each cathode wire 2.

[0037] Furthermore, one end of the upper rotating insulating shaft 6 extends out of the housing and is connected to a transmission gear 7. The drive motor drives the upper rotating insulating shaft 6 through the drive gear meshing with the transmission gear 7. In this way, the drive motor, drive gear, and transmission gear 7 are all arranged on the outside of the housing, and only the upper rotating insulating shaft 6, upper roller 8, lower conductive shaft 5, lower roller 1, cathode wire 2, and dust removal shovel 3 are retained inside the housing, achieving physical isolation between the high-voltage electrostatic precipitator area and the external mechanical transmission area. During inspection and maintenance, there is no need to enter the high-humidity, high-pressure interior of the housing, making operation safe and convenient.

[0038] In a preferred embodiment, both the transmission gear 7 and the drive gear are bevel gears, with multiple drive gears mounted on the same drive shaft, which is connected to the drive motor. Using bevel gear transmission converts the horizontal rotational motion of the drive motor into vertical rotational motion of the upper rotating insulating shaft 6, resulting in smooth transmission and high load-bearing capacity. Mounting multiple drive gears on the same drive shaft allows one drive motor to simultaneously drive multiple upper rotating insulating shafts 6, further simplifying the transmission system, reducing equipment costs, and ensuring the synchronization of the movement of multiple rows of cathode wires 2. The drive motor can be a variable frequency speed control motor, which flexibly adjusts the running speed of the cathode wires 2 according to the dust concentration in the flue gas and the ash accumulation rate of the cathode wires 2 during operation, achieving a balance between energy saving and ash scraping effect.

[0039] In another embodiment of the present invention, the transmission mechanism can also adopt a worm gear transmission, that is, a worm is mounted on the drive shaft, and the worm meshes with the transmission gear 7 to drive the upper rotating insulating shaft 6. The worm gear transmission has the characteristics of large transmission ratio, smooth transmission, good self-locking, and compact structure. It is suitable for converting the rotational motion of the drive motor arranged in the horizontal direction into the rotational motion of the upper rotating insulating shaft 6 in the vertical direction. In the case of synchronous driving of multiple rows of cathode wires 2, multiple worm segments can be machined on different sections of the same drive shaft and mesh with the corresponding transmission gears 7 respectively, so as to realize that one drive motor synchronously drives multiple upper rotating insulating shafts 6. This not only ensures the synchronicity of the movement of each row of cathode wires 2, but also further simplifies the transmission system, reduces equipment costs, and facilitates equipment layout and maintenance.

[0040] It should be noted that the above-mentioned matching relationship between the drive motor and the bevel gear, as well as the matching relationship between the drive motor and the worm and transmission gear 7, are all conventional transmission arrangements in mechanical design. Their installation methods, connection structures, lubrication and protection methods all follow conventional mechanical design practices. This invention has not made any improvements to their matching structures. Therefore, the specific assembly structure of the drive motor and the bevel gear is not shown separately in the accompanying drawings of this invention.

[0041] The present invention also provides a cleaning method for the above-mentioned wet electrostatic precipitator with a cleanable cathode, comprising the following steps: S10. Flue Gas Dust Removal: Flue gas enters the anode tube 4 from bottom to top. Flushing water is sprayed above the anode tube 4. The cathode wire 2 is connected to a high-voltage direct current to generate a corona electric field, purifying the flue gas passing through the anode tube 4. Specifically, flue gas containing droplets and oil dust enters the flue gas distribution chamber from the bottom of the casing. After being rectified by the distribution plate, it is evenly distributed to each anode tube 4 and flows upwards. The flushing water sprayed above the anode tube 4 forms a thin water film flowing downwards on the inner wall of the anode tube 4, which is used to flush out the captured dust and droplets and also plays an auxiliary role in dust removal. After the cathode wire 2 is connected to a high-voltage direct current, a corona discharge is generated on its surface, charging the flowing dust and droplets. Under the action of the electric field, the charged particles migrate towards the inner wall of the anode tube 4 with the opposite charge and are captured, thereby achieving flue gas purification.

[0042] S20. Cathode Cleaning: During flue gas dust removal, the drive motor drives the upper rotating insulated shaft 6 to rotate. The upper rotating insulated shaft 6 drives the upper roller 8, cathode wire 2, and lower roller 1 to rotate synchronously. The cathode wire 2 continuously passes through the stationary dust removal shovel 3, which scrapes and removes the accumulated ash from the surface of the cathode wire 2. This step is performed simultaneously with the flue gas dust removal, without stopping the machine or interrupting the dust removal process. During the cyclical movement of the cathode wire 2, the sticky dust, sludge, and condensed ash adhering to its surface are continuously scraped off by the stationary dust removal shovel 3. The cathode wire 2 always maintains a clean discharge surface, fundamentally preventing corona blockage caused by ash covering the cathode wire 2 and maintaining a stable corona discharge effect. Each time the dust removal shovel 3 completes a scraping, a fresh discharge tip is exposed in the corresponding section of the cathode wire 2, and the corona current returns to the rated level, ensuring long-term stable dust removal efficiency.

[0043] S30. Waste Discharge: The scraped-off waste is flushed downwards by its own weight and the flushing water sprayed from above the anode tube 4. The ash scraped off by the dust scraper 3 is flushed downwards along with the thin water film flowing from top to bottom on the inner wall of the anode tube 4, and then collected at the drain port at the bottom of the shell before entering the ash water treatment system, completing the collection and discharge of waste. The entire discharge process is continuous, without the need to increase the spray water volume; the existing thin water film on the inner wall of the anode tube 4 is sufficient to carry away the scraped-off waste.

[0044] In this invention, the cathode wire 2 forms a ring around the upper roller 8 and the lower roller 1, and circulates along the ring path under the drive of the drive motor. During the circulatory movement, the cathode wire 2 segment passing through each anode tube 4 continuously slides relative to the fixed dust removal shovel 3. The dust removal shovel 3 scrapes the surface of the cathode wire 2, continuously scraping off the adhering dust, sludge, and condensed ash. Compared with the existing technology where the cathode wire 2 is fixedly suspended and relies on spray flushing water or manual cleaning during shutdown, this invention achieves online, continuous, and mechanical removal of cathode ash. It does not require a large flow of flushing water specifically for ash removal, nor does it require shutdown, and has significant advantages in water saving, energy saving, and continuous operation. At the same time, the transmission gear 7, drive motor, and other transmission components are all arranged on the outside of the housing, and only the rotating insulating shaft, rollers, and dust removal shovel 3 are retained inside the housing, eliminating safety hazards such as leakage and creepage short circuits.

[0045] It should be noted that the present invention adopts a modular structure, which can be directly adapted to existing hexagonal honeycomb wet electrostatic precipitators for modification without altering the original anode tube 4 and high-voltage power supply system. The modification cost is low and the compatibility is wide. During the modification, it is only necessary to add a dust removal shovel 3 and its support at the corresponding position at the bottom of the original anode tube 4, replace the original fixed cathode wire 2 with an annular cathode wire 2 wound around the upper and lower rollers, add a transmission gear 7 and a drive motor at the protruding end of the upper rotating insulating shaft 6 on the outside of the shell, and connect it to the power supply and control system to complete the upgrade. The modification workload is small, the construction period is short, and the impact on the operation of the production equipment is limited.

[0046] The above-described embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

Claims

1. A wet electrostatic precipitator with a cleanable cathode, characterized in that, include: The housing contains multiple hexagonal anode tubes arranged in a honeycomb array, and each anode tube contains a cathode wire. A cathode rotation drive mechanism includes an upper roller and a lower roller. The upper roller is mounted on an upper rotating insulating shaft, which is connected to the housing and supported at the upper end of the anode tube. The lower roller is mounted on a lower conductive shaft, which is connected to the housing and supported at the lower end of the anode tube. The cathode wire passes around the upper roller and the lower roller in sequence to form a ring. The upper rotating insulating shaft is driven to rotate by a drive motor located outside the housing. The upper rotating insulating shaft drives the upper roller to rotate, and the cathode wire and the lower roller move synchronously. The dust removal mechanism includes a dust removal shovel, which is fixed to the bottom of the anode tube, and the edge of the dust removal shovel scrapes against the surface of the cathode wire.

2. The wet electrostatic precipitator with a cleanable cathode according to claim 1, characterized in that, The dust removal shovel is conical, and a wire-passing hole is provided in the center of the dust removal shovel. The cathode wire passes through the wire-passing hole, and there is a clearance fit between the wire-passing hole and the cathode wire. The edge of the wire-passing hole scrapes against the surface of the cathode wire, and the conical surface of the dust removal shovel points in the opposite direction to the movement direction of the cathode wire at that point.

3. The wet electrostatic precipitator with a cleanable cathode according to claim 1, characterized in that, The dust removal shovel is a double-pyramidal shape, and a wire-passing hole is provided in the center of the dust removal shovel. The cathode wire passes through the wire-passing hole, and there is a clearance fit between the wire-passing hole and the cathode wire. The edge of the wire-passing hole makes scraping contact with the surface of the cathode wire.

4. The wet electrostatic precipitator with a cleanable cathode according to claim 2 or 3, characterized in that, The conical surface of the dust removal shovel is rounded and blunted.

5. The wet electrostatic precipitator with a cleanable cathode according to claim 2 or 3, characterized in that, The dust removal shovel is made of wear-resistant fiberglass or 316L stainless steel.

6. The wet electrostatic precipitator with a cleanable cathode according to claim 1, characterized in that, The upper roller is fixedly connected to the upper rotating insulating shaft, the lower roller is fixedly connected to the lower conductive shaft, and the upper rotating insulating shaft and the lower conductive shaft are respectively rotatably connected to the housing.

7. The wet electrostatic precipitator with a cleanable cathode according to claim 1, characterized in that, The upper rotating insulating shaft is made of polytetrafluoroethylene insulating material, and the lower roller is a conductive and corrosion-resistant roller.

8. The wet electrostatic precipitator with a cleanable cathode according to claim 1, characterized in that, The upper rollers corresponding to each row of anode tubes are mounted on the same upper rotating insulating shaft, and the lower rollers corresponding to the upper rollers are mounted on the same lower conductive shaft.

9. The wet electrostatic precipitator with a cleanable cathode according to claim 1, characterized in that, One end of the upper rotating insulating shaft extends out of the housing and is connected to a transmission gear. The drive motor drives the upper rotating insulating shaft through the drive gear meshing with the transmission gear.

10. The wet electrostatic precipitator with a cleanable cathode according to claim 9, characterized in that, Both the transmission gear and the drive gear are bevel gears, and multiple drive gears are mounted on the same drive shaft, which is connected to the drive motor.

11. A cleaning method, characterized in that, Cleaning using a wet electrostatic precipitator with a cleanable cathode as described in any one of claims 1 to 10 includes the following steps: S10: Flue gas dust removal: Flue gas is introduced into the anode tube from bottom to top, and flushing water is sprayed above the anode tube. The cathode wire is connected to a high-voltage direct current to generate a corona electric field, which purifies the flue gas passing through the anode tube. S20: Cathode cleaning: During the flue gas dust removal process, the drive motor drives the upper rotating insulating shaft to rotate, the upper rotating insulating shaft drives the upper roller to rotate, and drives the cathode wire to move synchronously with the lower roller. The cathode wire continuously passes through the fixed dust removal shovel, and the dust removal shovel scrapes and contacts the surface of the cathode wire to remove the accumulated dust on the surface of the cathode wire. S30: Waste Discharge: The scraped-off waste is flushed downwards and discharged by its own weight and the flushing water sprayed above the anode tube.

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