A self-cleaning device for purifying and recycling water in plastic granulation

Abstract

The present application relates to the technical fields of industrial circulating water purification and recycling, and particularly relates to a self-cleaning device for purifying and recycling plastic granulation circulating water, which comprises a filter main body, the filter main body has a machine body, the machine body is provided with a water inlet, a water outlet and a blowdown port, a filter cavity and a clean water cavity communicated with the water outlet are formed in the machine body, a supporting cylinder seat is arranged between the filter cavity and the clean water cavity, and a divided filter cylinder is rotatably installed on the supporting cylinder seat; an offline warehouse sealing and cleaning assembly is arranged on one side of the divided filter cylinder close to the blowdown port; and a differential pressure energy storage and indexing assembly is arranged on the machine body and connected with the filter cavity and the clean water cavity respectively. Compared with the prior art, the offline warehouse sealing and cleaning structure formed by the divided filter cylinder, the partition rib, the filter window, the sludge collecting tank and the outer sealing scraping lip can concentrate and discharge the trapped pollutants, which is beneficial to maintaining the continuous purification and recycling of the plastic granulation circulating cooling water.

Description

Technical Field

[0001] This invention relates to the field of industrial circulating water purification and reuse technology, and in particular to a self-cleaning device for purifying and reusing circulating water in plastic granulation. Background Technology

[0002] In the plastic granulation process, extruded strips, hot-cut pellets, or water-cooled pellets typically require a large amount of circulating cooling water for cooling, transport, and initial cleaning. To reduce the amount of fresh water needed and the amount of wastewater discharged, the circulating cooling water is usually purified and reused within the production system. As the system circulates, fine plastic powder, flexible plastic filaments, pulp-like suspended solids, waxy precipitates, and a small amount of settled particles gradually accumulate in the water, forming a pollution load primarily composed of suspended solids and flexible adhering substances. These pollutants differ from ordinary sand particles; they easily adhere to the edges of filter screen pores and gradually form a flexible clogged layer. If they cannot be separated and discharged in time during circulation, it will not only increase the suction resistance of the circulating water pump and cause fluctuations in cooling water flow, affecting the cooling stability and pelletizing uniformity of the plastic strips, but also increase the need for shutdown cleaning, wastewater drainage, and fresh water replenishment, hindering the continuous purification and reuse of circulating water in plastic granulation and the recycling of water resources.

[0003] In the prior art, Chinese patent document CN120242576A, entitled "A Dual-Swirl High-Efficiency Automatic Filter Backwashing Device," discloses a filter body for industrial circulating water treatment, equipped with backwash water inlet, backwash air inlet, backwash drainage and exhaust, and sewage discharge pipelines. The filtration and backwashing states are switched via valves and a backwash water supply pump to achieve automatic backwashing of the circulating water filtration equipment. This solution can be used for the filtration, purification, and backwashing maintenance of industrial circulating water, but its backwashing process mainly relies on multiple valves and external water or air supply to switch the overall operating conditions of the filter. For suspended pollutants in plastic granulation circulating water, such as flexible plastic filaments, fine powder, and waxy adhering substances, which easily form a clogging layer, there is still room for improvement in how to effectively isolate the locally clogged filter surface from the main filtered water flow without interrupting the purification and reuse of the main circulating water loop, and how to utilize the pressure difference before and after filtration to trigger directional rotation, pulse backwashing, and synchronous sewage discharge. Summary of the Invention

[0004] In view of this, the purpose of this invention is to propose a self-cleaning device for the purification and reuse of circulating water in plastic granulation, so as to solve the problem that existing plastic granulation circulating water treatment equipment is unable to effectively separate the filter surface cleaning area from the main filtration water flow when removing suspended pollutants such as flexible plastic filaments, fine powder and waxy adhering matter. This results in the easy rerolling of stripped impurities, the difficulty in reverse ejection of blockages deep in the filter pores, and the easy ineffective continuous operation of the cleaning action, thereby improving the stability of continuous purification and reuse of circulating cooling water.

[0005] To achieve the above objectives, this invention provides a self-cleaning device for circulating water purification and reuse in plastic granulation, comprising a filter body with a casing, an inlet, an outlet, and a drain outlet. The casing forms a filter chamber and a clean water chamber connected to the outlet. A support cylinder is provided between the filter chamber and the clean water chamber. A segmented filter cartridge is rotatably mounted on the support cylinder, with both ends of the segmented filter cartridge forming a sealed rotatable fit with the support cylinder, thus isolating the filter chamber and the clean water chamber except through the filter windows of the segmented filter cartridge. Circulating water entering the filter chamber is filtered and purified through the filter windows before entering the clean water chamber. The outlet is only connected to the clean water chamber. The segmented filter cartridge forms multiple filter windows circumferentially. Offline sealing and cleaning... The washing component, specifically the offline sealing chamber cleaning component, is located on the side of the segmented filter cartridge near the drain outlet. It forms a cleaning chamber separated from the main filtration water flow in the filter chamber when any filter window rotates to the cleaning position. The cleaning chamber is connected to the drain outlet. The differential pressure energy storage and shifting component is located on the machine body and is connected to the filter chamber and the clean water chamber for pressure tapping. The differential pressure energy storage and shifting component is linked with the segmented filter cartridge and the offline sealing chamber cleaning component. It drives the segmented filter cartridge to intermittently rotate through one filter window position when the pressure difference between the filter chamber and the clean water chamber increases. After rotation, it outputs pulsed clean water in the reverse direction to the filter window in the cleaning chamber, causing the blockage on the filter window to be removed from the main filtration water flow and discharged through the drain outlet.

[0006] Preferably, the outer periphery of the segmented filter cartridge is provided with several dividing ribs, and a filter window is formed between two adjacent dividing ribs. A wedge-shaped filter plate is fixedly installed in the filter window, with the water inlet side of the wedge-shaped filter plate facing the filter chamber and the water outlet side of the wedge-shaped filter plate facing the clean water chamber.

[0007] Preferably, the offline sealing and cleaning assembly has a sludge collection tank located on the lower side of the support cylinder seat. The edge of the sludge collection tank is continuously provided with an outer sealing lip. The outer sealing lip and the partition ribs on both sides of the filter window that have been turned to the cleaning position are elastically attached to form a flow-blocking seal. The sludge collection tank and the outer side of the filter window together form a cleaning and sealing chamber that is separated from the main filtered water flow of the filter chamber.

[0008] Preferably, a central clean water pipe is installed inside the segmented filter cartridge, and the central clean water pipe is connected to the clean water chamber. An inner sealing guide lip is provided on the side of the central clean water pipe facing the cleaning and sealing chamber. A backwash spray slit is opened on the inner sealing guide lip, and the backwash spray slit corresponds to the inner side of the filter window that has been turned to the cleaning position.

[0009] Preferably, the differential pressure energy storage transposition component has a pulse water storage bladder, which is a compressible water storage structure. The pulse water storage bladder is connected to the clean water chamber through a one-way water supply valve and to the backflush jet slit through a pulse valve port. The one-way water supply valve is used to allow clean water in the clean water chamber to enter the pulse water storage bladder, and the pulse valve port is used to output pulse clean water to the backflush jet slit when the pulse water storage bladder is compressed.

[0010] Preferably, the differential pressure energy storage transposition component has a differential diaphragm box, which includes a housing, an elastic diaphragm disposed within the housing, and a thrust part linked to the elastic diaphragm. A high-pressure working chamber and a low-pressure working chamber are formed on both sides of the elastic diaphragm, respectively. The high-pressure working chamber is connected to the filter chamber through a high-pressure tapping pipe, and the low-pressure working chamber is connected to the purified water chamber through a low-pressure tapping pipe. The thrust part is connected to a drive rod. A pawl is hinged on the drive rod, and a ratchet is coaxially fixed at one end of the segmented filter cartridge. The pawl meshes with the ratchet. A pressure bladder plate that can move axially with the drive rod is fixedly disposed on the drive rod, and the pressure bladder plate corresponds to the pulse water storage bladder.

[0011] Preferably, a limit spring is provided between the drive rod and the machine body, and a delayed contact gap is reserved between the pressure plate of the pressure bladder and the pulse water storage bladder. The drive rod passes through the indexing stroke section and the cleaning stroke section in sequence under the push of the differential membrane box. The indexing stroke section is used to drive the ratchet to rotate by one tooth pitch through the pawl to drive the segmented filter cartridge to rotate through one filter window position. At this time, the pressure plate of the pressure bladder has not yet compressed the pulse water storage bladder. In the cleaning stroke section, the pawl no longer pushes the ratchet, and the pressure plate of the pressure bladder crosses the delayed contact gap and compresses the pulse water storage bladder.

[0012] Preferably, one end of the segmented filter cartridge is provided with several angular positioning grooves along the circumference, and a positioning pin is elastically installed on the support cylinder seat. The positioning pin is adapted to the angular positioning groove, and the angular positioning groove is set one-to-one with the filter window.

[0013] Preferably, a drain valve core is provided inside the drain outlet, and a valve core lever is provided on the drain valve core. The valve core lever is driven by a lever fork actuation structure and drives the drive rod. When the drive rod is in the reset position and the rotation stroke section, the drain valve core remains closed. When the drive rod enters the cleaning stroke section, the drive rod drives the valve core lever through the lever fork actuation structure, so that the drain valve core opens the drain outlet.

[0014] Preferably, the drain outlet is connected to a drain pipe, an observation cover is provided on the machine body at the position corresponding to the cleaning and sealing chamber, and a flow stabilizing baffle is provided between the water inlet and the segmented filter cartridge. The flow stabilizing baffle is used to reduce the direct impact of circulating water on the segmented filter cartridge after entering the filtration chamber.

[0015] The beneficial effects of this invention are:

[0016] This type of plastic granulation circulating water purification and reuse self-cleaning device forms an offline sealed chamber cleaning structure through compartmentalized filter cartridges, partition ribs, filter windows, sludge collection tank, and external sealing scraper lip. This prevents heavily clogged filter windows from being directly scraped or sucked up in the main filtration water flow. Instead, they are first transferred to a cleaning sealed chamber separated from the filtration chamber and then undergo reverse pulse cleaning. The detached plastic filaments, fine powder, and waxy adhering substances directly enter the sludge collection tank and are discharged from the drain outlet. This reduces the probability of contaminants being re-entrained by the main flow, improves the flux recovery effect after filter window cleaning, and helps maintain the continuous purification and stable reuse of circulating cooling water.

[0017] Based on the aforementioned offline sealing structure, a differential pressure energy storage and displacement structure is formed by a differential membrane box, a drive rod, a pawl, a ratchet, a pressure bladder plate, and a pulse water storage bladder. The differential membrane box utilizes the clogging pressure difference between the filter chamber and the clean water chamber to generate axial thrust on the effective pressure area of ​​the elastic membrane, and outputs the thrust to the drive rod. This causes the equipment to first drive the segmented filter cartridge to rotate through one filter window position, and then the pressure bladder plate, which moves with the drive rod, compresses the pulse water storage bladder to output short-term high-flow-rate clean water. This solves the problem of insufficient flushing force when relying solely on the natural pressure backwash of the clean water chamber, and at the same time avoids ineffective continuous cleaning when the filter window is not clogged.

[0018] While achieving segmented rotation and pulse backwashing, the filter window's stopping position and backwashing opening sequence are limited by the angle positioning groove, positioning pin, drain valve core, and valve core lever. This ensures that the filter window only opens for backwashing and outputs backwash water after reaching the cleaning and sealing chamber, achieving a continuous action effect of "blockage triggering, single-cell offline, pulse top cleaning, and synchronous backwashing." This reduces downtime for disassembly and cleaning and ineffective drainage, which helps reduce water loss during the circulating water purification process. It is suitable for continuous purification and reuse of circulating cooling water in plastic granulation production lines. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0021] Figure 2 This is a schematic diagram of the internal cross-sectional structure of the body of the present invention;

[0022] Figure 3 This is a schematic diagram of the segmented filter cartridge and support cylinder seat structure of the present invention;

[0023] Figure 4 This is a schematic diagram of the offline sealing and cleaning component structure of the present invention;

[0024] Figure 5 This is a schematic diagram of the central water purification pipe and backflushing spray joint structure of the present invention;

[0025] Figure 6 This is a schematic diagram of the differential pressure energy storage transposition component of the present invention;

[0026] Figure 7 This is a schematic diagram of the structure of the drain valve core and drive rod of the present invention.

[0027] Figure 8 This is a schematic diagram of the offline sealing and cleaning operation of the filter window of the present invention;

[0028] Figure 9 This is a schematic diagram of the automatic cleaning process of the present invention.

[0029] The diagram is marked as follows:

[0030] 1. Body; 2. Inlet; 3. Outlet; 4. Drain; 5. Filter chamber; 6. Clean water chamber; 7. Support cylinder base; 8. Compartmentalized filter cartridge; 9. Separating rib; 10. Filter window; 11. Wedge-shaped filter plate; 12. Central clean water pipe; 13. Cleaning and sealing chamber; 14. Outer sealing lip; 15. Inner sealing guide lip; 16. Sludge collection tank; 17. Backflush spray slit; 18. Pulse water storage bladder; 19. One-way water supply valve; 20. Pulse valve port; 21. Differential diaphragm box; 22. High-pressure tapping pipe; 23. Low-pressure tapping pipe; 24. Drive rod; 25. Pawl; 26. Ratchet; 27. Pressure bladder plate; 28. Limiting spring; 29. ​​Angle positioning groove; 30. Positioning pin; 31. Drain valve core; 32. Valve core lever; 33. Drain pipe; 34. Observation cover; 35. Flow stabilizing baffle. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0032] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] like Figures 1 to 9As shown, the plastic granulation circulating water purification and reuse self-cleaning device includes a filter body 1, which has an inlet 2, an outlet 3, and a drain 4. The filter body 1 contains a filter chamber 5 and a clean water chamber 6 connected to the outlet 3. A support cylinder 7 is provided between the filter chamber 5 and the clean water chamber 6. A segmented filter cylinder 8 is rotatably mounted on the support cylinder 7. Both ends of the segmented filter cylinder 8 form a sealed rotatable fit with the support cylinder 7, isolating the filter chamber 5 and the clean water chamber 6 except through the filter windows 10 of the segmented filter cylinder 8. Circulating water entering the filter chamber 5 is filtered and purified by the filter windows 10 before entering the clean water chamber 6. The outlet 3 is only connected to the clean water chamber 6. The segmented filter cylinder 8 forms multiple filter windows 10 circumferentially. An offline sealing and cleaning assembly is also included. The offline sealing chamber cleaning component is located on the side of the segmented filter cartridge 8 near the drain port 4, and is used to form a cleaning sealing chamber 13 that is separated from the main filtered water flow of the filter chamber 5 when any filter window 10 is rotated to the cleaning position. The cleaning sealing chamber 13 is connected to the drain port 4. The differential pressure energy storage and shifting component is located on the body 1 and is connected to the filter chamber 5 and the clean water chamber 6 respectively. The differential pressure energy storage and shifting component is linked with the segmented filter cartridge 8 and the offline sealing chamber cleaning component. When the pressure difference between the filter chamber 5 and the clean water chamber 6 increases, it drives the segmented filter cartridge 8 to rotate intermittently through one filter window 10 position, and after the rotation, it outputs pulsed clean water in the reverse direction to the filter window 10 in the cleaning sealing chamber 13, so that the blockage on the filter window 10 is removed from the main filtered water flow and discharged from the drain port 4.

[0034] In actual manufacturing, the body 1 can be made of stainless steel or carbon steel with an anti-corrosion layer on the inner wall. The length of the body 1 can be set from 600mm to 1800mm according to the circulating water flow rate of the plastic granulation production line. The inlet 2 is preferably located on the side of the body 1 near the filter chamber 5, the outlet 3 is preferably located on the side of the body 1 near the clean water chamber 6, and the drain outlet 4 is located at the bottom of the body 1 near the cleaning and sealing chamber 13. The two ends of the segmented filter cartridge 8 are preferably sealed and rotated with the support cylinder seat 7 through sealed bearings, so that there is no direct bypass flow path between the filter chamber 5 and the clean water chamber 6 except through the filter window 10, and the outlet 3 is only connected to the clean water chamber 6. After entering the filter chamber 5 from the inlet 2, the circulating water surrounds the outside of the segmented filter cartridge 8. Under the pressure of the circulating pump, it enters the inside of the segmented filter cartridge 8 and the clean water chamber 6 from the outside of the filter window 10. The circulating water purified by the filter window returns to the plastic granulation cooling water tank or the circulating pipeline through the outlet 3. This forms a path for the filtration, purification and reuse of circulating cooling water. Plastic powder, flexible plastic filaments, pulp-like suspended matter and waxy adhering matter are trapped on the outside of the filter window 10. As the amount of trapped material increases, the pressure difference between the filter chamber 5 and the clean water chamber 6 gradually increases. When the pressure difference increases to the action value of the pressure difference energy storage and displacement component, the pressure difference energy storage and displacement component drives the segmented filter cartridge 8 to rotate past one filter window 10 position, so that the heavily clogged filter window 10 enters the cleaning position. The outer side of the filter window 10 that enters the cleaning position is no longer directly exposed to the main filtered water flow of the filter chamber 5, but forms a cleaning chamber 13 together with the offline sealing chamber cleaning component. After that, pulsed clean water is sprayed out from the inside to the outside of the filter window 10 in the opposite direction, pushing out the fine powder and adhering material embedded in the edge of the filter hole. The detached impurities enter the drain port 4 with the sewage. Other filter windows 10 that do not enter the cleaning chamber 13 continue to filter normally. Therefore, the equipment can complete the offline pulse cleaning of a single filter window 10 without stopping the machine, while avoiding the traditional scraper structure from pressing flexible impurities into the filter hole.

[0035] Furthermore, in this embodiment, the triggering basis of the differential pressure storage transposition component is the overall pressure difference change between the filter chamber 5 and the purified water chamber 6, rather than identifying the blockage of a single filter window 10. As plastic powder, flexible plastic filaments, and waxy adhesive gradually adhere to the inlet side of multiple filter windows 10, the inlet resistance on the filter chamber 5 side increases, and the outlet pressure on the purified water chamber 6 side decreases relatively. The high-pressure tapping pipe 22 and the low-pressure tapping pipe 23 apply the pressure on both sides to the elastic diaphragm of the differential diaphragm box 21, and the resulting pressure difference generates an axial thrust on the effective pressure-bearing area of ​​the elastic diaphragm, which is transmitted to the drive rod 24 through the thrust part, thereby causing the drive rod 24 to enter the cleaning trigger stroke from the reset position.

[0036] like Figures 2 to 5As shown, the outer periphery of the segmented filter cartridge 8 is provided with several dividing ribs 9, and a filter window 10 is formed between two adjacent dividing ribs 9. A wedge-shaped filter plate 11 is fixedly installed in the filter window 10. The water inlet side of the wedge-shaped filter plate 11 faces the filter chamber 5, and the water outlet side of the wedge-shaped filter plate 11 faces the clean water chamber 6. The offline sealing chamber cleaning assembly has a sludge collection tank 16 located on the lower side of the support cylinder seat 7. An outer sealing lip 14 is continuously provided along the edge of the sludge collection tank 16. The outer sealing lip 14 and the dividing ribs 9 on both sides of the filter window 10 when it is turned to the cleaning position are elastically attached to form a flow-blocking seal. The sludge collection tank 16 and the outer side of the filter window 10 together form a cleaning sealing chamber 13 that is separated from the main filtered water flow of the filter chamber 5. A central clean water pipe 1 passes through the segmented filter cartridge 8. 2. The central water purification pipe 12 is connected to the water purification chamber 6. The central water purification pipe 12 is provided with an inner sealing guide lip 15 on the side facing the cleaning chamber 13. The inner sealing guide lip 15 is provided with a backwash spray slit 17, which corresponds to the inner side of the filter window 10 that has been turned to the cleaning position. The differential pressure energy storage and displacement assembly has a pulse water storage bladder 18. The pulse water storage bladder 18 is a compressible water storage structure. The pulse water storage bladder 18 is connected to the water purification chamber 6 through a one-way water supply valve 19 and to the backwash spray slit 17 through a pulse valve port 20. The one-way water supply valve 19 is used to allow clean water in the water purification chamber 6 to enter the pulse water storage bladder 18. The pulse valve port 20 is used to output pulse clean water to the backwash spray slit 17 when the pulse water storage bladder 18 is compressed.

[0037] The segmented filter cartridge 8 is preferably cylindrical. Both ends of the segmented filter cartridge 8 are preferably mounted on the support base 7 via sealed bearings. This allows the segmented filter cartridge 8 to rotate relative to the support base 7 while forming a sealed rotational fit to block the bypass water path between the filter chamber 5 and the purified water chamber 6 around the filter window 10. The outer diameter of the segmented filter cartridge 8 can be set to 240mm to 900mm. The number of filter windows 10 can be set to 8, 10, 12, or 16 depending on the processing capacity. The dividing ribs 9 extend axially along the segmented filter cartridge 8 and serve as the partition boundary between the filter windows 10. The wedge-shaped filter plate 11 can be a stainless steel wedge wire filter plate or a sintered wedge-shaped filter plate. The wedge width can be set to 0.10mm to 0.80mm. During filtration, circulating water passes through the wedge-shaped filter plate 11 from one side of the filter chamber 5 into the purified water chamber 6. During backwashing, pulsed purified water flows from the wider side of the wedge-shaped filter plate 11 to the narrower side, thereby creating a reverse push against the plastic powder and waxy substances stuck at the slit opening. The sludge collection tank 16 is preferably a long tank extending axially along the compartmentalized filter cylinder 8. The outer sealing scraper lip 14 is continuously arranged along the edge of the sludge collection tank 16 and can be made of wear-resistant polyurethane, fluororubber, or silicone rubber. After the outer sealing scraper lip 14 elastically fits into the partition rib 9, it forms a flow-blocking seal to prevent the main flow of the filter chamber 5 from entering the cleaning chamber 13. The outer sealing scraper lip 14 can also slightly scrape off the thicker sheet-like adhering material on the outside of the filter window 10 when the compartmentalized filter cylinder 8 is rotated. The central clean water pipe 12 is fixed on the support cylinder seat 7 and does not rotate with the compartmentalized filter cylinder 8. The inner sealing guide lip 15 is set close to the inside of the filter window 10 in the cleaning position, so that the pulse clean water output by the backwash spray slit 17 is limited within the range of the filter window 10 and will not diffuse to the inside of the adjacent filter window 10. The pulse water storage bladder 18 can be a pressure-resistant rubber bladder, a metal corrugated bladder, or a small water storage chamber with an elastic diaphragm. During normal filtration, the clean water in the clean water chamber 6 is replenished into the pulse water storage bladder 18 through the one-way water supply valve 19. The one-way water supply valve 19 restricts the backflow of clean water in the pulse water storage bladder 18 to the clean water chamber 6. When the differential pressure energy storage displacement component compresses the pulse water storage bladder 18, the pulse valve port 20 opens and sends short-term high-flow-rate clean water into the backwash spray slit 17, so that the filter window 10 is quickly backwashed in a state of isolation from the main filtration water flow, achieving the effect of generating a high peeling force with less clean water.

[0038] like Figures 3 to 7As shown, the differential pressure energy storage transposition assembly has a differential diaphragm box 21. The differential diaphragm box 21 includes a housing, an elastic diaphragm disposed within the housing, and a thrust part linked to the elastic diaphragm. A high-pressure working chamber and a low-pressure working chamber are formed on both sides of the elastic diaphragm, respectively. The high-pressure working chamber is connected to the filter chamber 5 through a high-pressure tapping pipe 22, and the low-pressure working chamber is connected to the purified water chamber 6 through a low-pressure tapping pipe 23. The thrust part is connected to the drive rod 24. The differential diaphragm box 21, the drive rod 24, the pressure bladder plate 27, and the pulse water storage bladder 18 are disposed at the pressure tapping and execution position on the outside of the machine body 1. A pawl 25 is hinged on the drive rod 24, and a ratchet 26 is coaxially fixed at one end of the segmented filter cartridge 8. The pawl 25 meshes with the ratchet 26. The pressure bladder plate 27 is fixedly disposed on the drive rod 24 and can move axially with the drive rod 24. The pressure bladder plate 27 corresponds to the pulse water storage bladder 18. A limit spring 28 is provided between the drive rod 24 and the body 1. A delayed contact gap is reserved between the pressure plate 27 and the pulse water storage tank 18. The drive rod 24 passes through the indexing stroke section and the cleaning stroke section in sequence under the push of the differential membrane box 21. In the indexing stroke section, the pawl 25 pushes the ratchet 26 to rotate one tooth pitch to drive the segmented filter cartridge 8 to rotate through one filter window 10 position. In the cleaning stroke section, the pawl 25 no longer pushes the ratchet 26, and the pressure plate 27 crosses the delayed contact gap and compresses the pulse water storage tank 18. Several angle positioning grooves 29 are opened circumferentially at one end of the segmented filter cartridge 8. Positioning pins 30 are elastically installed on the support cylinder seat 7. The positioning pins 30 are adapted to the angle positioning grooves 29. The angle positioning grooves 29 are set one-to-one with the filter windows 10.

[0039] The differential diaphragm box 21 is installed in the pressure tapping seat on the outside of the machine body 1. The high-pressure tapping pipe 22 is connected to the filter chamber 5, and the low-pressure tapping pipe 23 is connected to the purified water chamber 6. In this embodiment, the differential diaphragm box 21 is used as a differential pressure actuator. Its elastic diaphragm bears the pressure of the filter chamber 5 and the purified water chamber 6 on both sides respectively. Let the pressure difference between the filter chamber 5 and the purified water chamber 6 be ΔP, and the effective pressure-bearing area of ​​the elastic diaphragm be A. Then, the theoretical differential pressure F acting on the thrust part is F = ΔP × A. In the design, by selecting the effective pressure-bearing area A of the elastic diaphragm, and combining the preload of the limit spring 28, the rotation resistance of the ratchet 26, and the compression resistance of the pulse water accumulator 18, the differential pressure output thrust is made greater than the maximum resistance required to complete one pitch rotation and subsequent compression of the pulse water accumulator 18. During normal filtration, the filter window 10 has sufficient flow, the pressure difference between the filter chamber 5 and the purified water chamber 6 is small, the differential membrane box 21 remains in its initial state, and the limit spring 28 keeps the drive rod 24 in the reset position. When the surface of the filter window 10 is covered with flexible plastic filaments, fine powder and waxy adhesive, the pressure in the filter chamber 5 increases while the pressure in the purified water chamber 6 decreases relatively. Under the action of the pressure difference, the differential membrane box 21 pushes the drive rod 24 forward through the thrust part. The forward displacement of the drive rod 24 is the indexing stroke segment. At this time, the pawl 25 pushes the ratchet 26 to rotate one tooth pitch. The ratchet 26 drives the segmented filter cartridge 8 to rotate through the angle corresponding to the filter window 10, so that the filter window 10 that was originally heavily clogged enters the cleaning chamber 13. The pressure plate 27 moves synchronously with the drive rod 24, but due to the delayed contact gap, it has not yet compressed the pulse water storage bladder 18. After the drive rod 24 continues to move forward and enters the cleaning stroke segment, the pawl 25 no longer pushes the ratchet 26. The pressure plate 27 crosses the delayed contact gap and begins to squeeze the pulse water storage bladder 18. The clean water in the pulse water storage bladder 18 enters the backwash spray slit 17 through the pulse valve port 20 and backwashes the filter window 10. The angular positioning groove 29 and the positioning pin 30 are used to form a mechanical positioning when the segmented filter cylinder 8 is rotated, so that the filter window 10 is exactly between the outer sealing scraper lip 14 and the inner sealing guide lip 15, to prevent the filter window 10 from being backflushed if it is not aligned with the cleaning sealing chamber 13; the limit spring 28 drives the drive rod 24 to reset after the pressure difference decreases, and the pawl 25 adopts a one-way pawl structure so that the drive rod 24 will not drive the ratchet 26 to rotate in the opposite direction when it resets.

[0040] To ensure that the rotation action precedes the backflush action, this embodiment employs a delayed contact gap between the pressure plate 27 and the pulse water storage tank 18, combined with the unidirectional transmission of the pawl 25 to achieve sequential engagement. During the initial displacement, the drive rod 24 preferentially drives the pawl 25 to push the ratchet 26, causing the segmented filter cartridge 8 to rotate through an angle corresponding to one filter window 10. At this time, the pressure plate 27 moves with the drive rod 24 but has not yet contacted and compressed the pulse water storage tank 18. When the positioning pin 30 enters the corresponding angle positioning groove 29, the filter window 10 in the cleaning position aligns with the sludge collection tank 16 and the outer sealing lip 14 to form the cleaning sealing chamber 13. Subsequently, the drive rod 24 continues into the cleaning stroke section.

[0041] Before the filter window 10 completes its rotation and positioning, the pressure plate 27 and the pulse water storage bladder 18 maintain the delayed contact gap. Therefore, the pressure plate 27 does not compress the pulse water storage bladder 18, and the backwash spray slit 17 does not output backwash water prematurely. After the filter window 10 enters the cleaning chamber 13, the drive rod 24 continues to enter the cleaning stroke section. The pressure plate 27 crosses the delayed contact gap and continues to move axially with the drive rod 24 to compress the pulse water storage bladder 18. The clean water in the pulse water storage bladder 18 is sprayed out briefly from the inside to the outside of the filter window 10 through the pulse valve port 20 and the backwash spray slit 17, thereby pushing out the blockages embedded in the slit opening and pore edge of the wedge-shaped filter plate 11.

[0042] like Figures 1 to 8 As shown, a drain valve core 31 is installed inside the drain outlet 4, and a valve core lever 32 is installed on the drain valve core 31. The valve core lever 32 is driven by the lever fork mechanism and is in transmission cooperation with the drive rod 24. When the drive rod 24 is in the reset position and the rotation stroke section, the drain valve core 31 remains closed. When the drive rod 24 enters the cleaning stroke section, the drive rod 24 drives the valve core lever 32 through the lever fork mechanism, so that the drain valve core 31 opens the drain outlet 4. The drain outlet 4 is connected to a drain pipe 33. An observation cover 34 is installed on the body 1 at the position corresponding to the cleaning sealing chamber 13. A flow stabilizing baffle 35 is installed between the water inlet 2 and the compartment filter cartridge 8. The flow stabilizing baffle 35 is used to reduce the direct impact of circulating water on the compartment filter cartridge 8 after entering the filter chamber 5.

[0043] The drain valve core 31 can be configured as a plunger valve core, a conical valve core, or a sliding plate valve core. Under normal conditions, the drain valve core 31 closes the drain port 4 or keeps the drain port 4 with only a very small discharge to prevent a large amount of circulating water from being lost from the drain port 4 during normal filtration. When the drive rod 24 enters the cleaning stroke section, the drive rod 24 drives the valve core lever 32 through the lever fork to move the structure and drive the drain valve core 31 to open the drain port 4. Since the filter window 10 has already entered the cleaning chamber 13 through the indexing stroke section, after the drain port 4 is opened, a discharge flow path is formed in the sludge collection tank 16 towards the drain pipe 33. The pulse clean water output by the backwash spray slit 17 pushes the blockage in the filter hole out from the inside of the filter window 10. The impurities will not return to the main flow of the filter chamber 5, but will directly enter the drain pipe 33 with the drained water in the cleaning chamber 13. After the filter window 10 is cleaned, the pressure difference between the filter chamber 5 and the clean water chamber 6 decreases. The limit spring 28 pushes the drive rod 24 to reset, the drain valve core 31 resets with the valve core lever 32 and closes the drain port 4 again, and the one-way water supply valve 19 allows clean water from the clean water chamber 6 to be replenished into the pulse water storage tank 18 again, preparing for the next cleaning. The observation cover 34 can be a transparent pressure-resistant cover or a detachable metal cover, which facilitates the observation of the wear and dirt accumulation of the outer sealing lip 14, filter window 10 and dirt collection tank 16. The flow stabilizing baffle 35 can be an arc-shaped perforated plate or a multi-hole baffle plate, so that the high-speed circulating water entering from the inlet 2 is first dispersed and then acts on the outer periphery of the compartment filter cartridge 8, avoiding premature wear of individual filter windows 10 due to local scouring. During use, the operator connects the inlet 2 to the return pipe of the plastic granulation circulating cooling water, connects the outlet 3 to the front end of the circulating water pump or the return end of the cooling water tank, and connects the sewage discharge pipe 33 to the sedimentation tank or the centralized sewage discharge pipe. After the equipment is started, the circulating water continuously passes through the filter window 10 for filtration. When the filter window 10 is blocked, causing the pressure difference to rise, the equipment automatically completes the rotation of one filter window 10, offline sealing, pulse backwashing and synchronous sewage discharge. The whole process does not require disassembling the filter screen or stopping the main circuit of the plastic granulation circulating water.

[0044] Furthermore, in this embodiment, the transmission mechanism between the valve core lever 32 and the drive rod 24 is specifically configured as a lever fork actuation structure. The lever fork transmits the axial displacement of the drive rod 24 to the valve core lever 32, so that the drain valve core 31 only opens after the drive rod 24 enters the cleaning stroke section, and remains closed when the drive rod 24 is in the reset position and the rotation stroke section. Through the linkage of the lever fork, the opening transmission of the drain valve core 31 and the rotation transmission of the pawl 25 and ratchet 26 act on different transmission positions of the drive rod 24, avoiding the drain valve transmission occupying the installation space of the pawl 25 and ratchet 26. As a result, the drain port 4 will not open prematurely during normal filtration or before the filter window 10 enters the cleaning sealing chamber 13, which can reduce the ineffective discharge of clean water or raw water, and make the drain opening timing correspond to the pulse backwash timing of the backwash spray slit 17.

[0045] When the filter window 10 is inside the cleaning chamber 13, the outer sealing lip 14 elastically fits against the partition ribs 9 on both sides of the filter window 10. The sludge collection tank 16 is located outside the filter window 10 and is connected to the drain port 4. Therefore, the plastic filaments, fine powder, and waxy adhering substances pushed out by the backwash water first enter the cleaning chamber 13 and the sludge collection tank 16, instead of being directly exposed to the main filtration water flow in the filter chamber 5. After the drain valve core 31 is opened, a discharge flow path pointing to the drain pipe 33 is formed inside the cleaning chamber 13. The detached impurities are discharged with a small amount of wastewater, thereby reducing the probability that impurities will be re-entrained by the main filtration water flow and re-attach to adjacent filter windows 10.

[0046] Since the flexible plastic filaments, fine plastic powder, and waxy precipitates in the plastic granulation circulating water constitute the main suspended and adherent pollutants, the flexible plastic filaments easily adhere to the surface of the filter window 10, the fine plastic powder easily embeds into the slits of the wedge-shaped filter plate 11, and the waxy precipitates easily form an adhesion layer on the filter surface, this embodiment uses the action sequence of "first isolation, then backflushing, and simultaneous sewage discharge" to ensure that the flexible blockages are pushed away by the reverse pulse purification water and carried away by the sewage discharge path after leaving the main filtration water flow. Compared with the method of directly scraping or continuously suctioning in the main filtration water flow, this can reduce the situation where flexible impurities are pressed into the filter holes or carried back to the filter surface by the mainstream, improve the flow recovery stability of the filter window 10 after cleaning, and maintain the continuous purification and reuse capacity of the circulating water.

[0047] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention (including the claims) is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of the different aspects of the invention as described above, which are not provided in the details for the sake of brevity.

[0048] This invention is intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A self-cleaning device for purifying and reusing circulating water in plastic granulation, used to filter and purify suspended pollutants in the circulating cooling water of plastic granulation and reuse the purified water for cooling water circulation, characterized in that, include: The filter body has a body (1), an inlet (2), an outlet (3) and a drain (4) on the body (1). The body (1) forms a filter chamber (5) and a clean water chamber (6) connected to the outlet (3). A support cylinder seat (7) is provided between the filter chamber (5) and the clean water chamber (6). A segmented filter cylinder (8) is rotatably installed on the support cylinder seat (7). The two ends of the segmented filter cylinder (8) form a sealed rotational fit with the support cylinder seat (7), so that the filter chamber (5) and the clean water chamber (6) are isolated from each other except through the filter window (10) of the segmented filter cylinder (8). The circulating water entering the filter chamber (5) enters the clean water chamber (6) after being filtered and purified by the filter window (10). The outlet (3) is only connected to the clean water chamber (6). The segmented filter cylinder (8) forms multiple filter windows (10) around its circumference. Offline sealing and cleaning assembly: The offline sealing and cleaning assembly is set on the side of the compartment filter cartridge (8) near the drain port (4) and is used to form a cleaning sealing chamber (13) separated from the filter chamber (5) when any filter window (10) is turned to the cleaning position. The cleaning sealing chamber (13) is connected to the drain port (4). The differential pressure energy storage transposition component is installed on the body (1) and is connected to the filter chamber (5) and the clean water chamber (6) respectively. The differential pressure energy storage transposition component is linked with the segmented filter cartridge (8) and the offline sealing and cleaning component. When the pressure difference between the filter chamber (5) and the clean water chamber (6) increases, the segmented filter cartridge (8) is driven to rotate intermittently through a filter window (10) position. After the rotation, the pulse clean water is output in reverse to the filter window (10) in the cleaning and sealing chamber (13), so that the suspended pollutants and blockages trapped on the filter window (10) are removed from the main filter water flow and discharged from the drain port (4).

2. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 1, characterized in that, The outer periphery of the segmented filter cylinder (8) is provided with several dividing ribs (9), and a filter window (10) is formed between two adjacent dividing ribs (9). A wedge filter (11) is fixedly installed in the filter window (10). The water inlet side of the wedge filter (11) faces the filter chamber (5), and the water outlet side of the wedge filter (11) faces the water purification chamber (6).

3. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 2, characterized in that, The offline sealing chamber cleaning assembly has a sludge collection tank (16) located on the lower side of the support cylinder seat (7). The edge of the sludge collection tank (16) is continuously provided with an outer sealing lip (14). The outer sealing lip (14) and the partition ribs (9) on both sides of the filter window (10) which has been turned to the cleaning position are elastically attached to form a flow-blocking seal. The sludge collection tank (16) and the outer side of the filter window (10) together form a cleaning sealing chamber (13) that is separated from the main filtered water flow of the filter chamber (5).

4. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 3, characterized in that, The compartmentalized filter cartridge (8) is equipped with a central water purification pipe (12), which is connected to the water purification chamber (6). The central water purification pipe (12) is provided with an inner sealing guide lip (15) on the side facing the cleaning chamber (13). A backwash spray slit (17) is opened on the inner sealing guide lip (15), which corresponds to the inner side of the filter window (10) that has been turned to the cleaning position.

5. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 4, characterized in that, The differential pressure energy storage transposition component has a pulse water storage bladder (18). The pulse water storage bladder (18) is a compressible water storage structure. The pulse water storage bladder (18) is connected to the clean water chamber (6) through a one-way water supply valve (19) and to the backwash jet (17) through a pulse valve port (20). The one-way water supply valve (19) is used to allow clean water in the clean water chamber (6) to enter the pulse water storage bladder (18). The pulse valve port (20) is used to output pulse clean water to the backwash jet (17) when the pulse water storage bladder (18) is compressed.

6. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 5, characterized in that, The differential pressure energy storage transposition assembly has a differential diaphragm box (21). The differential diaphragm box (21) includes a shell, an elastic diaphragm set in the shell, and a thrust part linked with the elastic diaphragm. A high-pressure working chamber and a low-pressure working chamber are formed on both sides of the elastic diaphragm. The high-pressure working chamber is connected to the filter chamber (5) through the high-pressure tapping pipe (22), and the low-pressure working chamber is connected to the water purification chamber (6) through the low-pressure tapping pipe (23). The thrust part is connected to the drive rod (24). A pawl (25) is hinged on the drive rod (24). A ratchet (26) is coaxially fixed at one end of the compartment filter cylinder (8). The pawl (25) meshes with the ratchet (26). A pressure bladder plate (27) is fixedly set on the drive rod (24). The pressure bladder plate (27) can move axially with the drive rod (24) and corresponds to the pulse water storage bladder (18).

7. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 6, characterized in that, A limit spring (28) is provided between the drive rod (24) and the body (1). A delayed contact gap is reserved between the pressure plate (27) and the pulse water storage tank (18). The drive rod (24) passes through the indexing stroke section and the cleaning stroke section in sequence under the push of the differential membrane box (21). In the indexing stroke section, the pawl (25) pushes the ratchet (26) to rotate one tooth pitch, so as to drive the segmented filter cartridge (8) to rotate through one filter window (10) position. The pressure plate (27) has not yet compressed the pulse water storage tank (18). In the cleaning stroke section, the pawl (25) no longer pushes the ratchet (26), and the pressure plate (27) crosses the delayed contact gap and compresses the pulse water storage tank (18).

8. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 7, characterized in that, One end of the segmented filter cylinder (8) is provided with several angle positioning grooves (29) along the circumference. A positioning pin (30) is elastically installed on the support cylinder seat (7). The positioning pin (30) is adapted to the angle positioning groove (29). The angle positioning groove (29) is set one-to-one with the filter window (10).

9. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 7, characterized in that, A drain valve core (31) is provided inside the drain outlet (4). A valve core lever (32) is provided on the drain valve core (31). The valve core lever (32) is driven by the lever fork lever structure and the drive rod (24). When the drive rod (24) is in the reset position and the rotation stroke section, the drain valve core (31) remains closed. When the drive rod (24) enters the cleaning stroke section, the drive rod (24) drives the valve core lever (32) through the lever fork lever structure, so that the drain valve core (31) opens the drain outlet (4).

10. The self-cleaning device for circulating water purification and reuse in plastic granulation according to claim 1, characterized in that, The drain outlet (4) is connected to a drain pipe (33). The body (1) is equipped with an observation cover (34) at the position corresponding to the cleaning and sealing chamber (13). A flow stabilizing baffle (35) is provided between the water inlet (2) and the compartment filter cartridge (8). The flow stabilizing baffle (35) is used to reduce the direct impact of circulating water on the compartment filter cartridge (8) after entering the filter chamber (5).

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