Self-cleaning filter screen for inlet of circulating water pump of thermal power plant

Abstract

The invention relates to the technical field of filter screen cleaning, in particular to a thermal power plant circulating water pump inlet self-cleaning filter screen which comprises a circulating water pool and a pipeline communicating the circulating water pool and a circulating water pump, and a filtering assembly, a cleaning assembly, a backflushing assembly and a blocking assembly are arranged in the pipeline; the filter assembly comprises a plurality of filter screens forming a circular truncated cone shape, so that impurities are guided to the edges of the filter screens, and interference of the impurities on the filter screens is reduced; the cleaning assembly drives the filter screen to rotate so as to scrape and clean impurities attached to the surface of the filter screen; the blocking assembly and the backflushing assembly are matched, the blocking assembly blocks water flow in front of the filter screen needing backflushing cleaning, and the backflushing assembly drives the filter screen to move and backflushes the filter screen so as to clean impurities in meshes of the filter screen.

Description

Technical Field

[0001] This invention relates to the technical field of filter cleaning, specifically to a self-cleaning filter screen at the inlet of a circulating water pump in a thermal power plant. Background Technology

[0002] The power generation efficiency of thermal power units is extremely sensitive to the flow rate and temperature of the condenser circulating cooling water. A 1-degree Celsius increase in the condenser terminal temperature difference affects coal consumption by approximately 2 g / kWh. The circulating water pool plays a crucial role in thermal power units, collecting the cooled water from the cooling tower to form a large cold water storage tank. The outlet of the circulating water pool is connected to the inlet of the circulating water pump, which then pumps the water from the pool to the condenser.

[0003] If debris in the circulating water, such as leaves, old packing debris, algae, etc., enters the condenser along with the circulating water, it will clog the condenser tubes, resulting in poor heat exchange, increased condenser terminal temperature difference, reduced vacuum, and reduced unit efficiency, causing significant economic losses.

[0004] Although most circulating water pumps in the industry are equipped with filters, and these filters come in various forms, they are still ordinary filters with simple structures, mainly flat filters. After a certain period of use, these filters will become clogged and require regular manual cleaning, which results in a large workload, poor manual cleaning effect, and long time. Summary of the Invention

[0005] The main objective of this invention is to provide a self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant, which aims to solve the problem in related technologies where filter screens become clogged, requiring regular manual cleaning, which is labor-intensive, has poor cleaning results, and affects the working efficiency of the equipment.

[0006] To achieve the above objectives, the technical solution provided by this invention is as follows: The present invention provides a self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant, comprising a circulating water tank and a pipe connecting the circulating water tank and the circulating water pump, wherein a filter assembly, a cleaning assembly, a backwashing assembly and a sealing assembly are provided inside the pipe. The filter assembly includes: a connecting plate, filter screens disposed on the connecting plate, multiple filter screens forming a frustum shape, and multiple connecting plates forming an annulus adapted to the inner wall of the pipe, with the top of the frustum facing the circulating water tank to guide some impurities to the edge of the filter assembly. The cleaning components include: a scraper and a drive unit that drives the filter assembly to rotate. The scraper is mounted on the pipe and is adapted to the filter assembly and the connecting plate. The backflushing assembly includes a limiting component and a driving component that causes the limiting component to slide along the axial direction of the pipe. Drive component one drives the connecting plate and filter screen to rotate relative to the scraper to clean the surface of the filter screen and connecting plate; when the filter assembly rotates past the limiting component, drive component two drives the limiting component to move so that the limiting component engages with the filter assembly, driving the filter assembly to move inside the pipeline; during the movement of the filter assembly, the filter assembly stops rotating; after the limiting component drives the filter assembly to move and complete the backflushing and resetting of the filter screen, the filter assembly resumes rotation, and then backflushing and cleaning multiple filter screens in sequence; The blocking component is installed at the pipe inlet to block the water flow in front of the filter component when it is backflushing.

[0007] Specifically, the filter assembly also includes: an arc-shaped connecting column provided inside the filter screen, and multiple connecting columns forming a hollow cylinder that is coaxial with the pipe; the drive component includes: a drive rod rotatably disposed inside the pipe, and a drive source for driving the drive rod to rotate, the drive rod being coaxially disposed within the cavity formed by multiple connecting columns to drive multiple filter assemblies to rotate.

[0008] Specifically, a stop is provided on the inner side of the arc-shaped connecting column, and a baffle is provided on the drive rod. When the drive rod rotates, the baffle abuts against the stop of one of the filter components, thereby driving all filter components to rotate synchronously.

[0009] Specifically, a connecting block is provided at the end of the connecting plate away from the filter screen, and a limiting block is provided on the connecting block. The limiting block is located between the connecting block and the inner wall of the pipe. An annular groove adapted to the limiting block is opened on the inner wall of the pipe. The annular groove is coaxially arranged with the pipe, and the limiting block is slidably arranged in the annular groove to limit the position of multiple filter components in the axial direction of the pipe.

[0010] Specifically, the limiting block is slidably mounted on the connecting block along the radial direction of the pipe, and an elastic element is provided between the limiting block and the connecting block to make the limiting block tend to move away from the connecting block; a sliding groove is provided on the inner wall of the lower side of the pipe along the axial direction of the pipe, the sliding groove is connected to the annular groove, and the depth of the sliding groove is greater than the depth of the annular groove, and the width of the sliding groove is adapted to the limiting block; when the drive rod drives the filter element to rotate until the limiting block moves to the sliding groove, the elastic element pushes the limiting block into the sliding groove to limit the filter element from continuing to rotate.

[0011] Specifically, the limiting components include: a sliding plate, a push block, and a reset block. The sliding plate is slidably disposed in the trough. The push block and the reset block are sequentially disposed on the sliding plate along the water flow direction. The side of the reset block closest to the push block is set as an inclined surface. When the sliding plate moves along the water flow direction, the push block abuts against the limiting block, causing the filter element to move synchronously to backflush the filter assembly. When the sliding plate moves in the opposite direction, the reset block abuts against the limiting block, resetting the filter assembly and pushing the limiting block out of the trough at the same time.

[0012] Specifically, the stop block is slidably mounted on the arc-shaped connecting column along the radial direction of the arc-shaped connecting column, and an elastic element 2 is provided between the stop block and the arc-shaped connecting column. The elastic element 2 pushes the stop block towards the drive rod, and the side of the stop block that abuts against the baffle is set as an inclined surface. When the limiting block moves into the slide groove, the baffle overcomes the elastic force of the elastic element 2 and passes over the stop block, so that the drive rod rotates relative to the filter assembly. When the limiting block moves out of the slide groove, it drives the filter assembly to rotate again.

[0013] Specifically, two scrapers are provided and are located on both sides of the filter assembly to be backwashed and at the junction of the adjacent filter assembly.

[0014] Specifically, the sealing assembly includes: a sealing plate and a drive source for sliding the sealing plate. The sealing plate is slidably mounted on the inner wall of the circulating water tank. When the filter assembly needs to be backwashed, the sealing plate moves to the scraper, and the sealing plate and the scraper abut against each other on the side away from the filter assembly. The sealing plate, the two scrapers and the inner wall of the pipe form a space with an opening in the direction of water flow to block the water flow through the filter assembly to be backwashed and interfere with the backwashing effect.

[0015] Specifically, a discharge port 1 is provided on the inner wall below the pipe, and a discharge port 2 is provided on the inner wall of the pipe on the side where the two scrapers are far apart from each other. That is, discharge port 1 is located between the two scrapers, and the two scrapers are located between the two discharge ports 2. A collection component is provided at discharge port 1 and discharge port 2. The collection component is connected to the inside of the pipe through discharge port 1 and the two discharge ports 2.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. By using multiple filter screens arranged in a frustum shape, some impurities can be guided to the connecting plate during filtration, thereby reducing interference from impurities on the filter screens, increasing the frequency of filter screen cleaning, reducing damage to the filter screens caused by frequent cleaning, and extending the service life of the filter screens.

[0017] 2. The cleaning component drives multiple filter screens to rotate synchronously relative to the scraper, scraping off the impurities adhering to the filter screens and connecting plates. The impurities are then discharged from the pipe through discharge port one and discharge port two into the collection component for centralized collection.

[0018] 3. The backwashing component sequentially drives the filter screens to backwash, thereby cleaning the impurities inside the filter screen mesh. This increases the cleaning effect, and while cleaning one filter screen, the others continue to perform their filtering function normally, without the need to stop the machine for cleaning, thus ensuring filtration efficiency. Attached Figure Description

[0019] Figure 1 This invention relates to a self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant.

[0020] Figure 2This is a schematic diagram of the structure of the filter component in this invention.

[0021] Figure 3 yes Figure 2 Enlarged diagram of point A in the middle.

[0022] Figure 4 This is a schematic diagram of the structure of the driving component one in this invention.

[0023] Figure 5 This is an exploded view of the filter component in this invention.

[0024] Figure 6 This is a schematic diagram of the pipe structure in this invention.

[0025] Figure 7 This is a partial explosion diagram of the recoil assembly in this invention.

[0026] Figure 8 This is a partial exploded view of the sealing component in this invention.

[0027] Figure 9 This is a schematic diagram showing the position of the sealing component when the filter screen of the present invention is in a backflushing state.

[0028] Figure 10 This is a schematic diagram showing the position of the filter assembly in the backwashing state in this invention.

[0029] The names of the parts in the attached diagram are: 1. Circulating water tank; 2. Pipeline; 21. Annular trough; 22. Discharge port one; 23. Discharge port two; 24. Slide chute; 3. Filter assembly; 31. Filter screen; 32. Connecting plate; 33. Arc-shaped connecting column; 331. Clearance groove; 332. Stop block; 333. Elastic component two; 34. Connecting block; 35. Limiting block; 36. Elastic component one; 37. Sealing plate; 4. Cleaning assembly; 41. Scraper; 42. 1. Drive component one; 421. Drive rod; 422. Drive source one; 423. Baffle; 5. Backlash assembly; 51. Limiting component; 511. Sliding plate; 512. Pushing block; 513. Reset block; 52. Drive component two; 521. Transmission rod; 522. Drive source two; 6. Sealing assembly; 61. Sealing plate; 62. Drive component three; 621. Rotating rod; 63. Extension plate; 7. Collection assembly. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0031] Reference Figures 1 to 10A self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant includes a circulating water tank 1 and a pipe 2 connecting the circulating water tank 1 and the circulating water pump. Multiple filter components 3, cleaning components 4, backwashing components 5, and sealing components 6 are installed inside the pipe 2.

[0032] Pipe 2 is installed between the outlet of the circulating water tank 1 and the inlet of the circulating water pump. Filter assembly 3 is installed inside pipe 2 on the side closest to the circulating water tank 1. Filter assembly 3 includes: connecting plate 32 and filter screen 31. Multiple sets of filter assembly 3 are provided. Multiple filter screens 31 form a frustum shape, with the side of the frustum with the smaller area facing the circulating water tank 1. Multiple connecting plates 32 form an annulus that fits the inner wall of pipe 2. In this embodiment, four sets of filter assembly 3 are provided. When impurities pass through the filter screen 31, some impurities are guided to the connecting plate 32 to reduce the impact of impurities on the filter screen 31.

[0033] The cleaning component 4 is used to clean the impurities adhering to the filter screen 31 and the connecting plate 32 when the filter screen 31 is clogged by driving the filter component 3 to rotate.

[0034] The backwash assembly 5 is used to backwash the filter screen 31 after the filter screen 31 becomes clogged by moving the filter assembly 3 along the axial direction of the pipe 2, that is, moving the filter screen 31 along the direction of water flow, so that the water flow reverses and passes through the filter screen 31, thereby cleaning the impurities in the mesh of the filter screen 31.

[0035] The blocking component 6 works in conjunction with the backwash component 5. When the backwash component 5 backwashes the filter screen 31, the blocking component 6 blocks the water flow in front of the filter screen 31 to prevent the water from flowing through the filter screen 31 in the backwashing state, thus affecting the backwashing effect.

[0036] Reference Figures 2 to 5 An arc-shaped connecting post 33 is fixedly installed inside the filter screen 31. The arc-shaped connecting posts 33 in the multiple filter components 3 form a hollow cylinder coaxial with the pipe 2. The cleaning component 4 includes a scraper 41 and a drive component 42. The scraper 41 is fixedly installed on the inner wall of the pipe 2, and the shape of the scraper 41 is adapted to the filter screen 31 and the connecting plate 32, that is, one end of the scraper 41 near the filter screen 31 and the connecting plate 32 respectively abuts against the filter screen 31 and the connecting plate 32. The drive component 42 is connected to the arc-shaped connecting post 33 to drive the multiple filter screens 31 and the connecting plate 32 to rotate.

[0037] Reference Figures 2 to 5A clearance groove 331 extending axially along the arc-shaped connecting column 33 is provided on the inner side of the arc-shaped connecting column 33. A stop block 332 is provided in the clearance groove 331, extending radially toward the arc-shaped connecting column 33. The driving component 42 includes a driving rod 421 and a driving source 422. The driving source is fixedly mounted on the pipe 2 and is used to drive the driving rod 421 to rotate. The driving rod 421 is rotatably mounted inside the pipe 2, and the axis of the driving rod 421 coincides with the axis of the pipe 2. The driving rod 421 is coaxially mounted with multiple arc-shaped connecting columns 33, and the driving rod 421 is rotatably mounted inside the hollow cylinder formed by the multiple arc-shaped connecting columns 33. A baffle 423 is fixedly mounted on the driving rod 421, and the baffle 423 is located in the clearance groove 331.

[0038] In this embodiment, the drive source 422 is a motor (not shown in the figure). The drive source 422 is fixedly installed on the outside of the pipe 2 and extends through the side wall of the pipe 2 into the pipe 2. A bevel gear set is provided between the output end of the drive source 422 and the drive rod 421 so that the drive rod 421 rotates when the output end of the drive source 422 rotates.

[0039] When the drive source 422 drives the drive rod 421 to rotate via the bevel gear set, the baffle 423 abuts against the stop block 332 to drive the arc-shaped connecting column 33 to rotate, thereby driving multiple filter screens 31 and connecting plates 32 to rotate synchronously. When the filter screens 31 and connecting plates 32 pass through the scraper 41, the scraper 41 removes the impurities adhering to the filter screens 31 and connecting plates 32.

[0040] Reference Figure 2 Figure 3 and Figure 6 A connecting block 34 is fixedly mounted on the connecting plate 32, and the connecting block 34 is located on the side of the connecting plate 32 away from the filter screen 31. A limiting block 35 is provided on the connecting block 34, and the limiting block 35 extends radially along the pipe 2. An annular groove 21 is formed on the inner wall of the pipe 2, and the annular groove 21 is coaxially arranged with the pipe 2. The annular groove 21 is adapted to the limiting block 35, that is, the width of the annular groove 21 is the same as the width of the limiting block 35 along the axial direction of the pipe 2. The limiting block 35 is slidably disposed within the annular groove 21 to limit the axial position of multiple filter elements within the pipe 2.

[0041] Reference Figures 2 to 7 A groove 24 is formed on the inner wall of pipe 2, located at the lowest point of the inner wall of pipe 2, and extends axially along pipe 2. The groove 24 communicates with an annular groove 21, and the depth of the groove 24 is greater than the depth of the annular groove 21. The width of the groove 24 is adapted to the limiting block 35. The backflushing assembly 5 includes a limiting member 51 and a driving member 52. The limiting member 51 is slidably disposed within the groove 24, and the driving member 52 is disposed on pipe 2 to drive the limiting member 51 to slide axially along pipe 2.

[0042] A cavity is formed in the connecting block 34, which is radially toward the inner wall of the pipe 2. The limiting block 35 is slidably disposed within the cavity of the connecting block 34. An elastic element 36 is disposed between the limiting block 35 and the connecting block 34, which is used to push the limiting block 35 toward the inner wall of the pipe 2. The limiting element 51 includes: a sliding plate 511, a pushing block 512, and a reset block 513. The sliding plate 511 is slidably disposed in the slide groove 24 and is connected to the driving element 52. The pushing block 512 is disposed on the side of the sliding plate 511 near the connecting plate 32, and the reset block 513 is disposed on the side of the pushing block 512 away from the connecting plate 32, and the pushing block 512 and the reset block 513 are separated. The distance between the pushing block 512 and the reset block 513 is used to accommodate the limiting block 35.

[0043] The side of the reset block 513 closest to the push block 512 is set as an inclined surface. The side of the reset block 513 closest to the axis of the pipe 2 is set as an arc-shaped guide surface that matches the contour of the bottom of the annular groove 21. That is, the curvature center of the arc-shaped guide surface coincides with the axis of the pipe 2, and its curvature radius is equal to or slightly larger than the curvature radius of the bottom of the annular groove 21.

[0044] When it is not necessary to backflush the filter screen 31, the reset block 513 corresponds to the annular groove 21 so that the limit block 35 can smoothly pass through the slide groove 24 and slide along the annular groove 21.

[0045] When backflushing of the filter screen 31 is required, the sliding plate 511 is moved by the second driving component 52 to control the reset block 513 to disengage from the annular groove 21, and to position the annular groove 21 between the push block 512 and the reset block 513. When the limiting block 35 of the corresponding filter assembly 3 moves to the slide groove 24, under the action of the first elastic component 36, the limiting block 35 moves into the slide groove 24, that is, the limiting block 35 moves between the push block 512 and the reset block 513, and the limiting block 35 abuts against the side wall of the slide groove 24, restricting the limiting block 35 from continuing to rotate. Then, the second driving component 52 controls the sliding plate 511 to move along the water flow direction, and the push block 512 abuts against the limiting block 35, driving the limiting block 35 to move along the slide groove 24, thereby driving the corresponding filter screen 31 to slide, so that the water flows through the filter screen 31 from the opposite direction, cleaning the impurities in the mesh of the filter screen 31.

[0046] After the filter screen 31 completes its backflushing operation, the second driving component 52 drives the sliding plate 511 to move in the opposite direction, so that the inclined surface of the reset block 513 abuts against the limiting block 35. Under the action of the first elastic component 36, the limiting block 35 is not able to slide towards the connecting block 34. When the limiting block 35 moves to the position of the annular groove 21, that is, when the limiting block 35 can no longer move, the force applied by the inclined surface of the reset block 513 to the limiting block 35 causes the limiting block 35 to overcome the elastic force of the first elastic component 36 and move closer to the connecting block 34. After the limiting block 35 abuts against the arc-shaped guide surface of the reset block 513, the corresponding filter assembly 3 can continue to rotate through the driving rod 421. The above operation is repeated to backflush the filter screens 31 of multiple filter assemblies 3 respectively. And when one filter screen 31 is backflushed, the other filter screens 31 can still work normally, so as to avoid the problem of filter equipment failure or need to be stopped when cleaning the filter screens 31.

[0047] Reference Figure 7 and Figure 10 The second driving component 52 includes: a transmission rod 521 and a second driving source 522 for rotating the transmission rod 521. The second driving source 522 is fixedly disposed on the outside of the pipe 2. The transmission rod 521 extends through the side wall of the pipe 2 into the pipe 2, and a gear is disposed at one end of the transmission rod 521 extending into the pipe 2. The gear is located in the slide groove 24. A groove extending along the axial direction of the pipe 2 is formed at one end of the sliding plate 511 near the bottom of the slide groove 24. A rack is fixedly disposed on the side of the groove, which is adapted to the gear, and the gear meshes with the rack. When the second driving source 522 drives the gear to rotate through the transmission rod 521, the gear drives the sliding plate 511 to move through the rack. In this embodiment, the second driving source 522 is a motor (not shown in the figure).

[0048] Reference Figure 5 The arc-shaped connecting column 33 has a cavity in the relief groove 331. The cavity in the relief groove 331 extends radially along the drive rod 421, and the cavity opening faces the drive rod 421. The stop block 332 is slidably disposed in the cavity in the relief groove 331, and an elastic element 333 is disposed between the stop block 332 and the arc-shaped connecting column 33. The elastic element 333 is used to push the stop block 332 toward the drive rod 421. Both the stop block 332 and the baffle 423 extend axially along the drive rod 421, and the side of the stop block 332 that abuts against the baffle 423 is set as an inclined surface.

[0049] When the limiting block 35 is not within the slide groove 24, the drive rod 421 rotates and abuts against the stop block 332 via the baffle 423. Under the action of the elastic element 333, the force exerted by the baffle 423 on the stop block 332 is insufficient to compress the elastic element 333. At this time, the drive rod 421 drives the corresponding filter assembly 3 to rotate. When the limiting block 35 of the filter assembly 3 moves into the slide groove 24, the slide groove 24 restricts the limiting block 35 from continuing to rotate. At this time, as the drive rod 421 continues to rotate, the force exerted by the baffle 423 on the stop block 332 increases. The baffle 423 acts on the inclined surface of the stop block 332 to overcome the elastic force of the elastic element and press the baffle 423 back into the cavity of the relief groove 331. At this time, the baffle 423 can pass over the stop block 332, and the drive rod 421 rotates relative to the filter assembly 3. After the filter screen 31 completes its backflushing, when the limiting block 35 moves into the annular groove 21, the limiting block 35 is no longer blocked by the sliding groove 24. When the baffle 423 abuts against the stop block 332 again, the drive rod 421 can drive the filter assembly 3 to rotate through the arc-shaped connecting column 33.

[0050] Without frequently stopping and starting the drive source 422, the drive source 422 continuously drives the drive rod 421 to rotate. The position of the sliding plate 511 is controlled by the drive source 522, allowing for different cleaning methods on the filter screen 31. Specifically, when the reset block 513 is opposite the annular groove 21, the drive source 422 drives the filter assembly 3 to rotate via the drive rod 421, scraping away impurities adhering to the surface of the filter screen 31 with the scraper 41, without backflushing the filter screen 31. When the reset block 513 is not within the range of the annular groove 21, the limit block 35 moves into the sliding groove 24, the filter assembly 3 stops rotating, and the sliding plate 511 is moved by the drive source 522, allowing for backflushing of the filter screen 31. These two cleaning methods improve the cleaning effect on the filter screen 31.

[0051] Reference Figure 5 and Figure 7 A sealing plate 37 is provided on the filter screen 31. The sealing plate 37 is located at the edge where two adjacent filter screens 31 contact each other, and extends radially toward the pipe 2 to seal the plane between the filter screen 31 and the arc-shaped connecting post 33. The sealing plate 37 also extends axially away from the filter screen 31 along the pipe 2. In this embodiment, each filter screen 31 is provided with two sealing plates 37, that is, the two sealing plates 37 and the filter screen 31 form a cavity with an opening facing the water flow direction. This ensures that when two adjacent filter screens 31 are at different positions along the axial direction of the pipe 2, water passing through different filter screens 31 cannot flow into the cavity formed by the other filter screens 31 and the sealing plate 37.

[0052] Reference Figure 2 and Figure 10The scraper 41 includes a blocking part and a scraping part. The scraping part is adapted to the filter screen 31 and the connecting plate 32 to scrape off impurities on the filter screen 31 and the connecting plate 32. The blocking part is located on the side of the scraper 41 away from the connecting plate 32 and extends radially along the pipe 2. The end of the scraper 41 near the inner wall of the pipe 2 is adapted to the inner wall of the pipe 2, that is, the side of the scraper 41 near the inner wall of the pipe 2 is in contact with the inner wall of the pipe 2.

[0053] In this embodiment, two scraper blades 41 are provided, which are arranged perpendicularly to each other, and the side of the scraper blade 41 away from the connecting plate 32 coincides with the side wall of the circulating water tank 1. When the limiting block 35 is in the slide groove 24, the two scraper blades 41 are respectively located at the junction of the filter screen 31 and the adjacent filter screens 31 on both sides, that is, each scraper blade 41 simultaneously abuts against the ends of two filter screens 31.

[0054] Reference Figure 8 and Figure 10 The sealing assembly 6 includes a sealing plate 61 and a driving component 62. The sealing plate 61 is slidably disposed on the side wall of the circulating water tank 1. The sealing plate 61 is fan-shaped, and in this embodiment, the fan shape is a quarter circle. The sealing plate 61 is located below the inlet of the pipe 2. The driving component 62 is disposed outside the circulating water tank 1 and is used to drive the sealing plate 61 to slide up and down. The side of the sealing plate 61 near the pipe 2 coincides with the side of the scraper 41 away from the connecting plate 32. In this embodiment, the driving rod 421 extends through the arc-shaped connecting post 33 to the side of the scraper 41 near the sealing plate 61. The side of the sealing part near the driving rod 421 is adapted to the driving rod 421, that is, the sealing part is set as an arc with the same radius as the driving rod 421. In this embodiment, when the filter screen 31 rotates, the plane of the end of the filter screen 31 near the scraper 41 coincides with the plane of the sealing part near the filter screen 31.

[0055] The side of the sealing plate 61 near the drive rod 421 is adapted to the drive rod 421, that is, the side of the sealing plate 61 near the drive rod 421 is set to be an arc with the same radius as the drive rod 421. When the sealing plate 61 is moved upward by the drive component 62 until the arc plate is coaxial with the pipe 2, the sealing plate 61 abuts against the side of the drive rod 421 and the sealing part of the two scrapers 41 respectively.

[0056] When a filter screen 31 needs to be backflushed, water flows through other filter screens 31. Simultaneously, the filter screen 31 moves away from the baffle plate 61, and water from the side of the filter screen 31 away from the baffle plate 61 passes through it and moves to the side of the filter screen 31 closer to the baffle plate 61, clearing impurities clogging the mesh of the filter screen 31. First, the baffle plate 61 is moved to a position coaxial with the pipe 2 by the drive component 62. Under the action of the baffle plate 61, scraper 41, and sealing plate 37, water can only flow through other filter screens 31, meaning the water flow at the filter screen 31 to be backflushed is essentially still. This prevents the flowing water from reducing the speed of the backflushing water relative to the filter screen 31; at this point, the speed of the backflushing water relative to the filter screen 31 is the speed of the filter screen 31 itself. This invention improves the backwashing effect on the filter screen 31, while the still water flow can prevent impurities backwashed from the filter screen 31 from being blown back onto the filter screen 31 and causing secondary clogging.

[0057] Reference Figure 8 and Figure 10 An extension plate 63 is provided on the sealing plate 61, extending radially along the fan-shaped plate. A groove is formed on the side of the extension plate 63 near the side wall of the circulating water tank 1. A rack 2 is fixedly installed on the side wall of the groove in the extension plate 63, extending radially along the sealing plate 61. The driving component 3 62 includes: a rotating rod 621, a gear 2, and a driving source 3. The rotating rod 621 penetrates the side wall of the circulating water tank 1 and rotates in a sealed manner with the side wall. A gear 2, adapted to the rack 2, is provided at one end of the rotating rod 621 inside the circulating water tank 1, meshing with the rack 2. The driving source 3 is fixedly installed on the outer wall of the circulating water tank 1 and connected to the rotating rod 621 located outside the circulating water tank 1 to drive the driving rod 421 to rotate. In this embodiment, the driving source 3 is a motor (not shown in the figure).

[0058] Reference Figure 6 and Figure 9A discharge port 1 22 and two discharge ports 23 are provided on the side wall of pipe 2. Discharge port 1 22 is located on the inner wall below pipe 2. Discharge ports 23 are located on the sides of pipe 2 opposite to the sides of the two scrapers 41 that are far apart from each other. That is, discharge port 1 22 is located between the two scrapers 41, and the two scrapers 41 are located between the two discharge ports 23. Both discharge ports 1 22 and discharge ports 23 penetrate the side wall of pipe 2. Discharge ports 23 are mainly used to discharge impurities adhering to filter screen 31 and connecting plate 32, while discharge port 1 22 is mainly used to discharge impurities backwashed from the mesh of filter screen 31. A collection component 7 is provided on the circulating water tank 1. The collection component 7 is adapted to pipe 2, that is, the collection component 7 is connected to the inside of pipe 2 through discharge port 1 22 and discharge ports 23, that is, impurities in pipe 2 move into the collection component 7 through discharge port 1 22 and discharge ports 23.

[0059] Specific work process: Water in circulating water tank 1 flows through filter assembly 3 in pipe 2 under the action of circulating water pump. Impurities in the water are intercepted by filter screen 31, and some impurities are guided to connecting plate 32. After a certain period of use, impurities will adhere to filter screen 31 or clog the mesh of filter screen 31, preventing water from passing through filter screen 31 smoothly and slowing down the water flow in pipe 2. By monitoring the decrease in water flow speed in pipe 2, it can be determined that the filter screen is clogged and needs to be cleaned.

[0060] At this time, drive source one 422 is turned on. Drive source one 422 drives the four filter screens 31 to rotate relative to the scraper 41 through drive rod 421, so as to scrape off the impurities adhering to the filter screens 31. At the same time, drive source two 522 and drive source three are turned on, and the water flow in front of the backflushing assembly 5 is blocked by the baffle 61. Then, the position of the sliding plate 511 is controlled by drive source two 522. The sliding plate 511 drives the corresponding filter screen 31 to slide and reset in the pipe 2, so as to backflush the filter screen 31. The scraped and backflushed impurities are collected in the collection assembly 7 through discharge port one 22 and discharge port two 23. After the scraping and backflushing operation of all four filter screens 31 is completed, the baffle 61 is reset by drive source three, and then drive source one 422 and drive source two 522 are stopped.

[0061] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant, comprising a circulating water tank and a pipe connecting the circulating water tank and the circulating water pump, characterized in that, The pipeline is equipped with a filter assembly, a cleaning assembly, a backflushing assembly, and a sealing assembly. The filter assembly includes: a connecting plate, filter screens disposed on the connecting plate, multiple filter screens forming a frustum shape, and multiple connecting plates forming an annulus adapted to the inner wall of the pipe, with the top of the frustum facing the circulating water tank to guide some impurities to the edge of the filter assembly. The cleaning components include: a scraper and a drive unit that drives the filter assembly to rotate. The scraper is mounted on the pipe and is adapted to the filter assembly and the connecting plate. The backflushing assembly includes a limiting component and a driving component that causes the limiting component to slide along the axial direction of the pipe. Drive component one drives the connecting plate and filter screen to rotate relative to the scraper to clean the surface of the filter screen and connecting plate; when the filter assembly rotates past the limiting component, drive component two drives the limiting component to move so that the limiting component engages with the filter assembly, driving the filter assembly to move inside the pipeline; during the movement of the filter assembly, the filter assembly stops rotating; after the limiting component drives the filter assembly to move and complete the backflushing and resetting of the filter screen, the filter assembly resumes rotation, and then backflushing and cleaning multiple filter screens in sequence; The blocking component is installed at the pipe inlet to block the water flow in front of the filter component when it is backflushing.

2. The self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant according to claim 1, characterized in that, The filter assembly also includes: an arc-shaped connecting column provided inside the filter screen, and multiple connecting columns forming a hollow cylinder that is coaxial with the pipe; the drive component includes: a drive rod rotatably disposed inside the pipe, and a drive source for driving the drive rod to rotate, the drive rod being coaxially disposed within the cavity formed by multiple connecting columns to drive multiple filter assemblies to rotate.

3. The self-cleaning filter screen at the inlet of a circulating water pump in a thermal power plant according to claim 2, characterized in that, A stop is provided on the inner side of the arc-shaped connecting column, and a baffle is provided on the drive rod. When the drive rod rotates, the baffle abuts against the stop of one of the filter components, thereby driving all filter components to rotate synchronously.

4. The self-cleaning filter screen at the inlet of a circulating water pump in a thermal power plant according to claim 2, characterized in that, A connecting block is provided at the end of the connecting plate away from the filter screen. A limit block is provided on the connecting block, and the limit block is located between the connecting block and the inner wall of the pipe. An annular groove adapted to the limit block is opened on the inner wall of the pipe. The annular groove is coaxial with the pipe. The limit block is slidably set in the annular groove to limit the position of multiple filter components in the axial direction of the pipe.

5. The self-cleaning filter screen at the inlet of a circulating water pump in a thermal power plant according to claim 4, characterized in that, The limiting block is slidably mounted on the connecting block along the radial direction of the pipe, and an elastic element is provided between the limiting block and the connecting block to make the limiting block tend to move away from the connecting block; a sliding groove is opened on the inner wall of the lower side of the pipe along the axial direction of the pipe, the sliding groove is connected to the annular groove, and the depth of the sliding groove is greater than the depth of the annular groove, and the width of the sliding groove is adapted to the limiting block; when the drive rod drives the filter element to rotate until the limiting block moves to the sliding groove, the elastic element pushes the limiting block into the sliding groove to limit the filter element from continuing to rotate.

6. A self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant according to claim 5, characterized in that the limiting member... include: The slide plate, push block, and reset block are arranged in a sliding groove. The slide plate is slidably set in the sliding groove. The push block and reset block are arranged in sequence on the slide plate along the water flow direction. The side of the reset block closest to the push block is set as an inclined surface. When the slide plate moves in the water flow direction, the push block abuts against the limit block, which drives the filter element to move synchronously to backwash the filter assembly. When the slide plate moves in the opposite direction, the reset block abuts against the limit block, which resets the filter assembly and pushes the limit block out of the sliding groove at the same time.

7. A self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant according to claim 3, characterized in that, The stop block is slidably mounted on the arc-shaped connecting column along the radial direction of the arc-shaped connecting column, and an elastic element 2 is provided between the stop block and the arc-shaped connecting column. The elastic element 2 pushes the stop block towards the drive rod, and the side of the stop block that abuts against the baffle is set as an inclined surface. When the limiting block moves into the slide groove, the baffle overcomes the elastic force of the elastic element 2 and passes over the stop block, so that the drive rod rotates relative to the filter assembly. When the limiting block moves out of the slide groove, it drives the filter assembly to rotate again.

8. The self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant according to claim 1, characterized in that, Two scrapers are provided and are located on both sides of the filter assembly to be backwashed and at the junction of the adjacent filter assembly.

9. A self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant according to claim 1, characterized in that, The sealing assembly includes: a sealing plate and a drive source for sliding the sealing plate. The sealing plate is slidably mounted on the inner wall of the circulating water tank. When the filter assembly needs to be backwashed, the sealing plate moves to the scraper, and the sealing plate and the scraper abut against each other on the side away from the filter assembly. The sealing plate, the two scrapers and the inner wall of the pipe form a space with an opening in the direction of water flow to block the water flow through the filter assembly to be backwashed and interfere with the backwashing effect.

10. A self-cleaning filter screen for the inlet of a circulating water pump in a thermal power plant according to claim 1, characterized in that, A discharge port 1 is provided on the inner wall below the pipe, and a discharge port 2 is provided on the inner wall of the pipe on the side where the two scrapers are far apart from each other. That is, discharge port 1 is located between the two scrapers, and the two scrapers are located between the two discharge ports 2. A collection component is provided at discharge port 1 and discharge port 2. The collection component is connected to the inside of the pipe through discharge port 1 and the two discharge ports 2.

Images