Self-cleaning filter and filtering method thereof

Abstract

The invention relates to the field of industrial filtering, and particularly discloses a self-cleaning filter and a filtering method thereof.The self-cleaning filter comprises a filter shell, a filter cartridge located in the filter shell and a self-cleaning unit, the self-cleaning unit comprises a stirring rod and a plurality of scraping cleaning assemblies, and each scraping cleaning assembly comprises an elastic scraping plate; the negative pressure suction assembly is mounted outside the filter shell; and a negative pressure suction cavity is formed in the supporting plate, and a suction opening in smooth transition with one side of the surface of the scraping plate is formed in the side, away from the stirring rod, of the negative pressure suction cavity of the supporting plate. According to the scheme, the scraping plate is driven by the stirring rod to scrape impurities on the inner wall of the filter cylinder, the scraped impurities and slurry materials can be accumulated on the surface of the plane-shaped scraping plate, and at the moment, the plane-shaped scraping plate can be matched with the negative pressure suction cavity and the suction opening to quickly suck the impurities and part of the slurry materials accumulated on the surface of the scraping plate.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial filtration, and particularly to a self-cleaning filter and a filtration method thereof. Background Art

[0002] A self-cleaning industrial filter is an industrial device that can automatically remove filter residues or pollutants and maintain filtration efficiency, and is widely used in fields such as water treatment, chemical industry, petroleum, food and pharmacy. Generally, it removes solid particles and impurities (such as sediment, rust, etc.) in slurry materials to ensure the cleanliness of the fluid; during use, without shutting down or disassembling, it automatically removes dirt on the filter mesh through backwashing, brushing, vibration, etc. The self-cleaning filter is designed to remove oversized particulate impurities and pollutants in slurry materials.

[0003] Currently, the self-cleaning filter allows slurry materials to continuously flow through the filter element for filtration. Inside, brushing is mostly used to remove oversized particles. The working principle is to continuously remove and discharge oversized pollutants by using the brushing inside the filter. The brushing adheres to the inner wall of the cylindrical filter element. The brushing rotates and cleans the inner wall of the filter element, causing large particulate impurities and pollutants to separate from the inner wall of the filter element, and then discharging them together with part of the slurry material from the bottom of the filter.

[0004] However, when filtering slurry materials with low flow rate and high viscosity, when the brushing cleans large particulate impurities and pollutants, the brushing is easily wrapped by the slurry material, and then it is difficult for the large particulate impurities and pollutants to separate from the brushing and be discharged; after long-term use, the fitting degree between the brushing and the inner wall of the filter element may decrease due to wear, resulting in partial pollutant residue, and the cylindrical structure of the inner wall of the filter element may cause poor contact of the scraping blades at the joints, resulting in incomplete cleaning; at the same time, when discharging large particulate impurities and pollutants, the large particulate impurities and pollutants cannot be completely discharged due to insufficient flow rate of the slurry material or design defects in the bottom structure, and are carried back to the filter element by the slurry material again. The above-mentioned various situations are likely to cause the filter element to be quickly blocked during the next filtration. Summary of the Invention

[0005] Aiming at the deficiencies in the prior art, the present invention provides a self-cleaning filter and a filtration method thereof to solve the problem that when the brushing cleans large particulate impurities and pollutants, the brushing is easily wrapped by the slurry material, and then it is difficult for the large particulate impurities and pollutants to separate from the brushing and be discharged.

[0006] To achieve the above object, the basic scheme of the present invention is as follows: A self-cleaning filter includes a filter housing, a filter cartridge located inside the filter housing, and a self-cleaning unit. The filter housing is provided with a feed port communicating with the filter cartridge and a discharge port communicating with the filter housing. The self-cleaning unit includes:

[0007] The stirring rod is vertically and coaxially installed inside the filter cartridge;

[0008] A plurality of scraping and cleaning components are circumferentially arranged on the outer wall of the stirring rod;

[0009] The scraping and cleaning component includes:

[0010] An elastic scraping plate;

[0011] A negative pressure suction component is installed outside the filter housing;

[0012] A support plate is provided with a suction chamber communicating with the negative pressure suction component; the support plate is vertically arranged, one side of the support plate is fixedly connected to the outer wall of the stirring rod, and the other side of the support plate is fixedly connected to the scraping plate;

[0013] The support plate is provided with a negative pressure suction chamber, and a suction port that smoothly transitions with one side of the surface of the scraping plate is provided on the side of the negative pressure suction chamber of the support plate away from the stirring rod.

[0014] The technical principle of the present invention is as follows: when the filtering ability of the filter cartridge in the self-cleaning filter becomes poor, the self-cleaning unit is started, the stirring rod drives the self-cleaning unit to rotate, the scraping plate on the self-cleaning unit fits on the inner wall of the filter cartridge, and the scraping plate drives by the stirring rod scrapes the impurities on the inner wall of the filter cartridge. The impurities and slurry materials after scraping can accumulate on the surface of the flat scraping plate. At this time, it can cooperate with the negative pressure suction chamber and the suction port to quickly suck the impurities and part of the slurry materials accumulated on the surface of the scraping plate, so that the part of the impurities and slurry materials are quickly sucked and discharged, improving the cleaning efficiency of the part of the impurities and slurry materials; at the same time, the surface of the scraping plate after suction is in a relatively clean state, which is convenient for preparing for the next self-cleaning process, improving the cleaning efficiency and cleanliness of the impurities on the inner wall of the filter cartridge.

[0015] Furthermore, the bottom of the filter housing is provided with a slag discharge chamber communicating with the filter cartridge and a slag discharge port communicating with the slag discharge chamber, and the slag discharge port is communicated with a slag discharge pipe;

[0016] The negative pressure suction component includes:

[0017] A negative pressure suction pipe, a first communication chamber communicating with the suction chamber is provided inside the stirring rod, and the inner wall of the first communication chamber of the stirring rod is smoothly transitioned with the inner wall of the suction chamber of the support plate;

[0018] A secondary negative pressure suction device is communicated with the negative pressure suction pipe, and the negative pressure suction pipe passes through the slag discharge pipe and the slag discharge port and is rotationally and sealingly communicated with the first communication chamber of the stirring rod.

[0019] With the above settings, the slag outlet and the slag discharge pipe can cooperate to quickly discharge the impurities and the slurry materials containing impurities in the filter housing and the filter cartridge, improving the slag discharge efficiency of the impurities; when discharging the impurities at the scraper, the auxiliary negative pressure suction device is started, and the negative pressure of the auxiliary negative pressure suction device is sequentially transmitted to the first communication cavity and the suction cavity through the negative pressure suction pipe. Since the suction port is opposite to the surface of the scraper, the impurities accumulated at the inner wall of the filter cartridge scraped by the scraper during the rotation of the scraper are sucked, enabling the impurities quickly scraped by the scraper to be quickly sucked and discharged. The suction position is targeted, and the impurities accumulated at the scraper can be accurately and quickly discharged.

[0020] Furthermore, it further includes a floating support assembly, and the floating support assembly includes:

[0021] A plurality of support rods, which are horizontally supported and installed between the support plate and the stirring rod;

[0022] A spring sleeved outside the support rod, one end of the spring is fixedly connected to the outer wall of the support rod, and the other end of the spring abuts and supports on the side of the support plate close to the stirring rod; a second communication cavity communicating the first communication cavity and the suction cavity is provided in the support rod, and the inner walls of the second communication cavity with the first communication cavity and the suction cavity are smoothly transitioned.

[0023] With the above settings, the spring and the support rod cooperate with the support plate and the scraper, so that the scraper closely fits on the inner wall of the filter cartridge, and then adjusts adaptively; when the scraper wears against the inner wall of the filter cartridge, the spring can adjust adaptively, making the scraper fit more closely on the inner wall of the filter cartridge, reducing the problem of insufficient fitting caused by wear loss; when discharging slag, the second communication cavity can connect the first communication cavity and the suction cavity, and the smoothly transitioned inner wall can make the slag discharge smoother.

[0024] Furthermore, the suction port is in a wide-mouth shape, and the length of the side of the suction port close to the scraper is the same as the height of the scraper.

[0025] With the above settings, the wide-mouth-shaped suction port can suck the scraper area in a larger range, improving the slag discharge efficiency and accuracy.

[0026] Furthermore, the scraper is an elastic silicone scraper, and a hydrophobic layer is provided on the surface of the scraper.

[0027] With the above settings, the elastic silicone scraper is more likely to stably fit on the inner wall of the filter cartridge and reduce the wear between the elastic silicone scraper and the inner wall of the filter cartridge; at the same time, when sucking the impurities at the scraper, the hydrophobic layer on the scraper makes the impurities on the scraper more easily separated from the scraper under the cooperation of the slurry material, improving the cleaning efficiency of the impurities.

[0028] Further, the slag discharge pipe is successively communicated with a slag discharge valve and a main negative pressure aspirator. A connecting pipe is installed between the slag discharge valve and the main negative pressure aspirator. A discharge pipe is provided on the auxiliary negative pressure aspirator, and the discharge pipe is communicated with the slag discharge pipe or the connecting pipe.

[0029] With the above arrangement, the discharge pipe can connect the slag discharge valve and the main negative pressure aspirator. When using the auxiliary negative pressure aspirator to aspirate impurities, the main negative pressure aspirator can be started at the same time. The main negative pressure aspirator can cooperate with the auxiliary negative pressure aspirator through the slag discharge pipe or the connecting pipe, so that when impurities are discharged at the auxiliary negative pressure aspirator, the discharge efficiency is further improved.

[0030] Further, it further includes a cleaning unit, and the cleaning unit includes:

[0031] A scraper;

[0032] A telescopic rod, the telescopic rod is vertically arranged, the lower end of the telescopic rod passes through the top of the filter housing and is located inside the filter housing, the scraper is fixedly installed at the lower end of the telescopic rod, the side wall of the scraper can be vertically attached to the side wall of the scraper plate, and the scraper can be attached to the inner wall of the filter cartridge;

[0033] A hydraulic pump for controlling the telescopic movement of the telescopic rod, the hydraulic pump is fixedly installed on the top of the filter housing;

[0034] A drive motor for driving the stirring rod to rotate, the drive motor is fixedly installed on the top of the filter housing.

[0035] With the above arrangement, the stirring rod stops rotating at the position of the scraper. The hydraulic pump is started, and the hydraulic pump controls the telescopic rod to extend. The lower end of the telescopic rod pushes the scraper downward. The scraper contacts the inner wall of the filter cartridge and the side wall of the scraper plate, and pushes the impurities remaining on the scraper plate to the slag discharge cavity, so that impurities are not likely to remain on the scraper plate, the impurities adhered to the scraper plate are reduced, the cleaning efficiency of the scraper plate for the filter cartridge and the accuracy during slag discharge aspiration are improved, and it also prepares for the next self-cleaning.

[0036] Further, it further includes a slag discharge hopper, and the slag discharge hopper includes:

[0037] A limiting hopper, the bottom end of the limiting hopper is in a sealed shape for the negative pressure suction pipe to pass through;

[0038] A guiding hopper sleeved outside the limiting hopper. Both the guiding hopper and the limiting hopper are installed in the slag discharge cavity. The upper end of the guiding hopper is detachably and sealingly connected to the lower end of the filter cartridge. The lower end of the guiding hopper is fixedly connected to the inner wall of the slag discharge port of the filter housing. The middle part of the guiding hopper is fixedly connected to the middle part of the limiting hopper. The lower end of the limiting hopper is fixedly and sealingly connected to the outer wall of the negative pressure suction pipe. A limiting slag discharge cavity is formed between the inner wall of the guiding hopper and the outer wall of the limiting hopper. The upper end of the longitudinal section of the limiting slag discharge cavity is vertically opposite to the scraper and the scraper.

[0039] With the above settings, the main negative pressure aspirator transmits the negative pressure to the slag discharge valve, the slag discharge pipe, and the slag discharge port in sequence. The slag discharge port transmits the negative pressure to the limit slag discharge cavity of the slag discharge hopper, thereby sucking the mixed material of the slurry material and impurities at the top of the guiding hopper and the limit hopper. The limit hopper and the guiding hopper can form the limit slag discharge cavity to accurately discharge the mixture of the slurry material and impurities on the inner wall of the filter cartridge, reducing the suction of the original unfiltered slurry material at the center of the filter cartridge, making the slag discharge treatment and the cleaning of the filter cartridge more accurate and reliable, with less recovery of the slurry material, and also reducing the self-cleaning recovery treatment cost.

[0040] The present invention also aims to provide a filtering method, including a self-cleaning filter according to any one of claims 1-8, and further including the following steps:

[0041] (a) Pretreatment stage: removing solid impurities with a particle size > 500 μm in the slurry material through a mechanical separation device;

[0042] (b) Filtration stage: pumping the pretreated slurry material into the self-cleaning filter, dynamically filtering the slurry material with a filter cartridge, monitoring the flow pressure P1 at the feed port of the filter cartridge housing and the flow pressure P2 at the discharge port, and obtaining the pressure difference ΔP = P2 - P1 and the numerical change of P2;

[0043] (c) Self-cleaning trigger stage: when ΔP reaches the threshold value of 0.3 - 0.5 bar, or the value of P2 drops to 70% of the rated value, temporarily close the feed port and start the self-cleaning program of the self-cleaning filter once, with a single self-cleaning program lasting 1 - 2 minutes;

[0044] (d) System recovery stage: after the single self-cleaning program is completed, open the feed port again, wait for 1 - 2 minutes, and verify whether the value of P2 has recovered to within ±10% of the rated value. If not, repeat step (c); if it has recovered, resume the filtration operation.

[0045] The technical principle of the present invention is as follows: in the pretreatment stage, the large-particle solid impurities in the slurry material are quickly physically removed to prepare for the subsequent self-cleaning filtration stage; in the filtration stage, by monitoring the flow pressure values of the slurry material at the feed port and the discharge port, the rapid filtration of the slurry material can be carried out smoothly, and the filtration process is smooth and the detection is in place; in the self-cleaning trigger stage, the ΔP and P2 in the filtration stage can be dynamically judged, and when one of the values of ΔP and P2 triggers the self-cleaning program, the self-cleaning program can be launched, and the self-cleaning program can be triggered in multiple scenarios to respond in a timely manner to the self-cleaning treatment of the filter cartridge.

[0046] Further, in step (c), when the self-cleaning step is started, the stirring rod drives the scraper and the support plate to rotate, and the auxiliary negative pressure suction device and the main negative pressure suction device are started simultaneously. The auxiliary negative pressure suction device transfers the negative pressure to the first communication cavity, the second communication cavity and the slag discharge cavity through the negative pressure suction pipe to suck the impurities accumulated at the scraper; meanwhile, the main negative pressure suction device transfers the negative pressure to the slag discharge pipe and the slag discharge port, and the slag discharge port transfers the negative pressure to the limit slag discharge cavity, so as to suck the mixed material of the slurry material and impurities at the top of the guiding hopper and the limit hopper; after the stirring rod rotates 5-10 r, the stirring rod rotates to the scraper, and the telescopic rod pushes the scraper downward, and the scraper contacts the inner wall of the filter cylinder and the side wall of the scraper to push the impurities remaining on the scraper to the limit slag discharge cavity.

[0047] Through the above settings, during the scraping process, the main negative pressure suction device and the auxiliary negative pressure suction device can synchronously suck the impurities. During the suction process, two channels are used for simultaneous suction. One is the rapid slag discharge suction system in the inner wall area of the filter cylinder composed of the main negative pressure suction device and the slag discharge hopper, and the other is the precision slag discharge suction system composed of the auxiliary negative pressure suction device, the stirring rod, the support rod, the support plate and the scraper. From the bottom side and the surface of the scraper, the inner wall of the filter cylinder can be accurately slag-discharged; the slag discharge hopper can guide, suck and discharge the slurry material mixed with impurities, and the limit hopper and the guiding hopper can form a limit slag discharge cavity to accurately discharge the mixture of the slurry material and impurities at the inner wall of the filter cylinder; at the same time, when the scraper cooperates with the filter cylinder and the scraper, the slurry material and impurities adhered to the flower plate can be pushed to the limit slag discharge cavity, so that the impurities adhered to the scraper are reduced, the cleaning efficiency of the scraper for the filter cylinder and the accuracy during slag discharge suction are improved, and preparations are made for the next self-cleaning. Brief Description of the Drawings

[0048] Figure 1 It is a schematic structural diagram of a self-cleaning filter in the axonometric direction in an embodiment of the present invention.

[0049] Figure 2 It is a schematic structural diagram of a self-cleaning filter in the top view direction in an embodiment of the present invention.

[0050] Figure 3 It is a sectional view taken along line A-A in the figure.

[0051] In the above-mentioned drawings: filter housing 10, feed inlet 101, discharge outlet 102, slag discharge port 103, slag discharge pipe 104, filter cartridge 20, stirring rod 301, drive motor 302, first communication cavity 303, scraper 401, support plate 402, suction cavity 403, suction port 404, negative pressure suction pipe 405, auxiliary negative pressure suction device 406, support rod 501, spring 502, second communication cavity 503, slag discharge valve 601, main negative pressure suction device 602, discharge pipe 603, scraping knife 701, telescopic rod 702, hydraulic pump 703, limiting hopper 801, guiding hopper 802, limiting slag discharge cavity 803. Detailed implementation manners

[0052] The technical solutions in the present invention will be further described below in conjunction with the drawings and embodiments.

[0053] This embodiment is basically as Figure 1 , Figure 2 and Figure 3 shown. An embodiment of the present invention provides a self-cleaning filter, including a filter housing 10, a filter cartridge 20 located inside the filter housing 10, a cleaning unit, a slag discharge hopper, and a self-cleaning unit. A feed inlet 101 communicating with the filter cartridge 20 is provided at the upper right end of the filter housing 10. A discharge outlet 102 is provided at the lower right side of the filter housing 10. A slag discharge cavity communicating with the filter cartridge 20 and a slag discharge port 103 communicating with the slag discharge cavity are provided at the bottom of the filter housing 10. The slag discharge port 103 is communicated with a slag discharge pipe 104.

[0054] As Figure 3As shown in the figure, the self-cleaning unit includes a stirring rod 301, two scraping and cleaning components, a negative pressure suction component, a floating support component, and a driving motor 302 that drives the stirring rod 301 to rotate. The driving motor 302 is fixedly installed on the top of the filter housing 10, and the stirring rod 301 is vertically and coaxially installed inside the filter cartridge 20; the two scraping and cleaning components are circumferentially and axially symmetrically arranged on the outer wall of the stirring rod 301; the scraping and cleaning component includes an elastic scraper 401 and a support plate 402, the scraper 401 is an elastic silicone scraper, and the surface of the scraper 401 is provided with a hydrophobic layer; the negative pressure suction component includes a negative pressure suction pipe 405 and a secondary negative pressure suction device 406, and the secondary negative pressure suction device 406 is installed outside the lower side of the filter housing 10; the floating support component includes a support rod 501 and a spring 502 sleeved outside the support rod 501; as shown in Figure 3, the support plate 402 is provided with a suction cavity 403 communicating with the negative pressure suction device component; the support plate 402 is vertically arranged, one side of the support plate 402 faces the outer wall of the stirring rod 301, and the other side of the support plate 402 is fixedly connected to the scraper 401 in an embedded manner, and the support rod 501 is horizontally supported and installed between the support plate 402 and the stirring rod 301; the support plate 402 is provided with a negative pressure suction cavity 403, and a suction port 404 that smoothly transitions with one side of the surface of the scraper 401 is provided on the side of the negative pressure suction cavity 403 of the support plate 402 away from the stirring rod 301. The suction port 404 is in a wide-mouth shape, and the length of the side of the suction port 404 close to the scraper 401 is the same as the height of the scraper 401.

[0055] As Figure 3 shown, a first communication cavity 303 communicating with the suction cavity 403 is provided inside the stirring rod 301, and the inner wall of the first communication cavity 303 of the stirring rod 301 smoothly transitions with the inner wall of the suction cavity 403 of the support plate 402; one end of the spring 502 is fixedly connected to the outer wall of the support rod 501, and the other end of the spring 502 abuts and supports on the side of the support plate 402 close to the stirring rod 301; a second communication cavity 503 communicating the first communication cavity 303 and the suction cavity 403 is provided inside the support rod 501, and the second communication cavity 503 smoothly transitions with the inner walls of both the first communication cavity 303 and the suction cavity 403; the secondary negative pressure suction device 406 is communicated with the negative pressure suction pipe 405, and the negative pressure suction pipe 405 passes through the slag discharge pipe 104 and the slag discharge port 103 and is rotationally and sealingly communicated with the first communication cavity 303 of the stirring rod 301.

[0056] As Figure 1 shown, the slag discharge pipe 104 is successively communicated with a slag discharge valve 601 and a main negative pressure suction device 602. A communication pipe is installed between the slag discharge valve 601 and the main negative pressure suction device 602. A discharge pipe 603 is provided on the secondary negative pressure suction device 406, and the discharge pipe 603 is communicated with the slag discharge pipe 104.

[0057] As Figure 1 、 Figure 2 and Figure 3As shown in the figure, the cleaning unit includes a scraper 701, a telescopic rod 702, and a hydraulic pump 703 for controlling the telescopic movement of the telescopic rod 702. The telescopic rod 702 is vertically arranged, and the lower end of the telescopic rod 702 passes through the top of the filter housing 10 and is located inside the filter housing. The scraper 701 is fixedly installed at the lower end of the telescopic rod 702. The side wall of the scraper 701 can be vertically attached to the side wall of the scraping plate 401, and the scraper 701 can be attached to the inner wall of the filter cartridge 20. The hydraulic pump 703 is fixedly installed on the top of the filter housing 10.

[0058] As Figure 3 shown, the slag discharge hopper includes a limiting hopper 801 and a guiding hopper 802 sleeved outside the limiting hopper 801. The bottom end of the limiting hopper 801 is in a sealed shape for the negative pressure suction pipe 405 to pass through. Both the guiding hopper 802 and the limiting hopper 801 are installed in the slag discharge cavity. The upper end of the guiding hopper 802 is detachably and sealingly connected to the lower end of the filter cartridge 20. The lower end of the guiding hopper 802 is fixedly connected to the inner wall of the slag discharge port of the filter housing 10. The middle part of the guiding hopper 802 is fixedly connected to the middle part of the limiting hopper 801. The lower end of the limiting hopper 801 is fixedly and sealingly connected to the outer wall of the negative pressure suction pipe 405. A limiting slag discharge cavity 803 is formed between the inner wall of the guiding hopper 802 and the outer wall of the limiting hopper 801. The upper end of the longitudinal section of the limiting slag discharge cavity 803 is vertically opposite to the scraping plate 401 and the scraper 701.

[0059] When filtering thick slurry materials, a filtering method is adopted, and a self-cleaning filter in this embodiment is used, which specifically includes the following steps:

[0060] (a) Pretreatment stage: Remove solid impurities with a particle size > 500 μm in the slurry material through a mechanical separation device, and heat the slurry material to adjust the viscosity of the slurry material.

[0061] (b) Filtration stage: Pump the pretreated slurry material into the self-cleaning filter. The slurry material enters the filter cartridge 20 through the feed port 101. The filter cartridge 20 is used for dynamic filtration of the slurry material. After the filter cartridge 20 filters the slurry material, it is discharged through the discharge port 102 of the filter housing 10. The filtration particle size of the filter element ≤ 15 μm. During this process, monitor the flow pressure P1 at the feed port 101 of the filter cartridge 20 housing and the flow pressure P2 at the discharge port 102, and obtain the pressure difference ΔP = P2 - P1 and the numerical change of P2.

[0062] (c) Self-cleaning trigger stage: When ΔP reaches the threshold value of 0.3 - 0.5 bar, or the value of P2 drops to 70% of the rated value, the feed inlet 101 is temporarily closed, and the self-cleaning program of the self-cleaning filter is started once. The single self-cleaning program lasts for 1 - 2 minutes. When the self-cleaning program is started, the drive motor 302 is started to drive the stirring rod 301 to rotate. The stirring rod 301 drives the support rod 501, the scraper 401, and the support plate 402 to rotate. At the same time, the secondary negative pressure suction device 406 and the primary negative pressure suction device 602 are started, and the slag discharge valve 601 is opened. At this time, the secondary negative pressure suction device 406 transmits the negative pressure through the negative pressure suction pipe 405 to the first communication cavity 303, the second communication cavity 503, and the suction cavity 403 in sequence. Since the suction port 404 is opposite to the surface of the scraper 401, the impurities accumulated at the inner wall of the filter cartridge 20 scraped by the scraper 401 during rotation are sucked, enabling the impurities quickly scraped by the scraper 401 to be quickly sucked and discharged. At the same time, the primary negative pressure suction device 602 transmits the negative pressure to the slag discharge valve 601, the slag discharge pipe 104, and the slag discharge port 103 in sequence. The slag discharge port 103 transmits the negative pressure to the limit slag discharge cavity 803 of the slag discharge hopper, and then sucks the mixed material of the slurry material and impurities at the top of the guiding hopper 802 and the limit hopper 801. After the stirring rod 301 rotates 5 - 10 revolutions, the rotation of the stirring rod 301 stops at the scraper 701. The hydraulic pump 703 is started, and the hydraulic pump 703 controls the telescopic rod 702 to extend. The lower end of the telescopic rod 702 pushes the scraper 701 downward. The scraper 701 contacts the inner wall of the filter cartridge 20 and the side wall of the scraper 401, and pushes the impurities remaining on the scraper 401 into the limit slag discharge cavity 803. Under the action of negative pressure, this part of the impurities is sucked and discharged at the limit slag discharge cavity 803.

[0063] (d) System recovery stage: After the single self-cleaning program is completed, the drive motor 302 pauses, the secondary negative pressure suction device 406 and the primary negative pressure suction device 602 pause simultaneously, and the slag discharge valve 601 closes. The feed inlet 101 is opened again. After waiting for 1 - 2 minutes, verify whether the value of P2 has recovered within the range of ±5% of the rated value. If not, repeat step (c); if it has recovered, resume the filtration operation.

[0064] During the above filtration process, in the pretreatment stage, the large-particle solid impurities in the slurry material are quickly physically removed first, preparing for the subsequent self-cleaning filtration stage, enabling the solid impurities larger than 500um to be quickly cleaned, and reducing the filtration pressure and difficulty in the subsequent self-cleaning filtration stage.

[0065] During the filtration stage, by monitoring the flow pressure values of the slurry material at the feed inlet 101 and the discharge outlet 102, the rapid filtration of the slurry material can be carried out smoothly, and the filtration process is smooth and the detection is in place.

[0066] During the self-cleaning trigger phase, it is possible to dynamically judge ΔP and P2 in the filtration phase. When one of the values of ΔP and P2 triggers the self-cleaning program, the self-cleaning program can be launched. The self-cleaning program can be triggered in multiple scenarios to promptly respond to the self-cleaning treatment of the filter cartridge 20.

[0067] During the self-cleaning program, the entire self-cleaning and slag discharging process can complete a self-cleaning cycle within 1 - 2 minutes. Thus, in step (d), it is possible to quickly judge whether the self-cleaning is in place. In step (d), the verification and monitoring of the P2 value are fast and convenient, enabling the entire self-cleaning filter to quickly enter the normal filtration step.

[0068] Meanwhile, in the self-cleaning trigger phase of (c), the stirring rod 301 can cooperate with two self-cleaning units to quickly scrape off the impurities adhering to the inner wall of the filter cartridge 20. During the scraping process, the spring 502 and the support rod 501 cooperate with the support plate 402 and the scraping plate 401, causing the scraping plate 401 to closely adhere to the inner wall of the filter cartridge 20 and then adjust adaptively.

[0069] When the scraping plate 401 wears against the inner wall of the filter cartridge 20, the spring 502 can adjust adaptively, causing the scraping plate 401 to more closely adhere to the inner wall of the filter cartridge 20, reducing the problem of insufficient adhesion caused by wear and tear. During the scraping process, the main negative pressure aspirator and the auxiliary negative pressure aspirator 406 can simultaneously aspirate the impurities. During the aspiration of the impurities, two channels are used for simultaneous aspiration. One is the rapid slag discharging aspiration system for the inner wall area of the filter cartridge 20 composed of the main negative pressure aspirator 602 and the slag discharging hopper, and the other is the precision slag discharging aspiration system composed of the auxiliary negative pressure aspirator, the stirring rod 301, the support rod 501, the support plate 402, and the scraping plate 401. From the bottom side and the surface of the scraping plate 401, it is possible to precisely perform slag discharging treatment on the inner wall of the filter cartridge 20, while reducing the aspiration of the original unfiltered slurry material at the center of the filter cartridge 20, making the slag discharging treatment and the cleaning of the filter cartridge 20 more accurate and reliable, and also reducing the recovery and treatment amount of the unfiltered part of the slurry material.

[0070] During the rapid slag discharging aspiration process for the inner wall area of the filter, the slag discharging hopper can guide, aspirate, and discharge the slurry material mixed with impurities. The limiting hopper 801 and the guiding hopper 802 can form a limiting slag discharging cavity 803 to precisely discharge the slurry material and impurity mixture at the inner wall of the filter cartridge 20. Meanwhile, when the scraper 701 cooperates with the filter cartridge 20 and the scraping plate 401, it can push the slurry material and impurities adhering to the flower plate to the limiting slag discharging cavity 803, reducing the impurities adhering to the scraping plate 401, improving the cleaning efficiency of the scraping plate 401 for the filter cartridge 20 and the precision during slag discharging aspiration, and also preparing for the next self-cleaning.

[0071] The efficiency of the entire self-cleaning process is higher and more accurate, the recovery amount of the slurry material is less, and the self-cleaning recovery treatment cost is also reduced; the entire process does not require operator operation at all, and the filter can achieve full-automatic filtration and slag discharge of the slurry material.

[0072] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the purpose and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A self-cleaning filter, comprising a filter housing, a filter cartridge located within the filter housing, and a self-cleaning unit. The filter housing is provided with a feed inlet communicating with the filter cartridge and a discharge outlet communicating with the filter housing, characterized in that, The self-cleaning unit includes: A stirring rod, which is vertically and coaxially installed inside the filter cylinder; A plurality of scraping and cleaning components, which are circumferentially arranged on the outer wall of the stirring rod; The scraping and cleaning component includes: An elastic scraping plate; A negative pressure suction component, which is installed outside the filter housing; A support plate, which is provided with a suction cavity communicated with the negative pressure suction component; the support plate is vertically arranged, one side of the support plate is fixedly connected to the outer wall of the stirring rod, and the other side of the support plate is fixedly connected to the scraping plate; The support plate is provided with a negative pressure suction cavity, and a suction port that smoothly transitions with one side of the surface of the scraping plate is arranged on the side of the negative pressure suction cavity of the support plate away from the stirring rod.

2. The self-cleaning filter according to claim 1, characterized in that, The bottom of the filter housing is provided with a slag discharge cavity communicated with the filter cylinder and a slag discharge port communicated with the slag discharge cavity, and the slag discharge port is communicated with a slag discharge pipe; The negative pressure suction component includes: A negative pressure suction pipe, and a first communication cavity communicated with the suction cavity is arranged inside the stirring rod, and the inner wall of the first communication cavity of the stirring rod smoothly transitions with the inner wall of the suction cavity of the support plate; A secondary negative pressure suction device, which is communicated with the negative pressure suction pipe, and the negative pressure suction pipe passes through the slag discharge pipe and the slag discharge port and is rotationally and sealingly communicated with the first communication cavity of the stirring rod.

3. The self-cleaning filter according to claim 1, wherein It further includes a floating support component, and the floating support component includes: A plurality of support rods, which are horizontally supported and installed between the support plate and the stirring rod; A spring sleeved outside the support rod, one end of the spring is fixedly connected to the outer wall of the support rod, and the other end of the spring abuts and supports on one side of the support plate close to the stirring rod; a second communication cavity communicating the first communication cavity and the suction cavity is arranged inside the support rod, and the second communication cavity smoothly transitions with the inner walls of the first communication cavity and the suction cavity.

4. The self-cleaning filter according to claim 1, characterized in that, The suction port is in a wide-mouth shape, and the length of the side of the suction port close to the scraping plate is the same as the height of the scraping plate.

5. The self-cleaning filter according to claim 4, wherein, The scraping plate is an elastic silica gel scraping plate, and a hydrophobic layer is arranged on the surface of the scraping plate.

6. The self-cleaning filter according to claim 5, characterized in that, The slag discharge pipe is sequentially communicated with a slag discharge valve and a main negative pressure suction device, a communication pipe is installed between the slag discharge valve and the main negative pressure suction device, a discharge pipe is arranged on the secondary negative pressure suction device, and the discharge pipe is communicated with the slag discharge pipe or the communication pipe.

7. The self-cleaning filter and its filtering method according to claim 1, characterized in that It further includes a cleaning unit, and the cleaning unit includes: A scraper; An expansion rod, which is vertically arranged, the lower end of the expansion rod passes through the top of the filter housing and is located inside the filter housing, the scraper is fixedly installed at the lower end of the expansion rod, the side wall of the scraper can be vertically attached to the side wall of the scraping plate, and the scraper can be attached to the inner wall of the filter cylinder; A hydraulic pump for controlling the expansion and contraction of the expansion rod, which is fixedly installed on the top of the filter housing; A drive motor for driving the stirring rod to rotate, which is fixedly installed on the top of the filter housing.

8. The self-cleaning filter and its filtering method according to claim 7, characterized in that, It further includes a slag discharge hopper, and the slag discharge hopper includes: A limiting hopper, and the bottom end of the limiting hopper is in a sealed shape for the negative pressure suction pipe to pass through; A guiding hopper sleeved outside a limiting hopper. Both the guiding hopper and the limiting hopper are installed in a slag discharge cavity. The upper end of the guiding hopper is detachably and sealingly connected to the lower end of the filter cartridge. The lower end of the guiding hopper is fixedly connected to the inner wall of the slag discharge port of the filter housing. The middle part of the guiding hopper is fixedly connected to the middle part of the limiting hopper. The lower end of the limiting hopper is fixedly and sealingly connected to the outer wall of the negative pressure suction pipe. A limiting slag discharge cavity is formed between the inner wall of the guiding hopper and the outer wall of the limiting hopper. The upper end of the longitudinal section of the limiting slag discharge cavity is vertically opposite to the scraper and the blade.

9. A filtering method, characterized in that, It includes a self-cleaning filter as described in any one of claims 1-8, and further includes the following steps: (a) Pretreatment stage: Remove solid impurities with a particle size > 500 μm in the slurry material through a mechanical separation device; (b) Filtration stage: Pump the pretreated slurry material into the self-cleaning filter, and use the filter cartridge to dynamically filter the slurry material. Monitor the flow pressure P1 at the feed port of the filter cartridge housing and the flow pressure P2 at the discharge port, and obtain the pressure difference ΔP = P2 - P1 and the numerical change of P2; (c) Self-cleaning trigger stage: When ΔP reaches the threshold value of 0.3-0.5 bar, or the value of P2 drops to 70% of the rated value, temporarily close the feed port, and start the self-cleaning program of the self-cleaning filter once. The single self-cleaning program lasts for 1-2 minutes; (d) System recovery stage: After the single self-cleaning program is completed, open the feed port again. After waiting for 1-2 minutes, verify whether the value of P2 has recovered within the range of ±10% of the rated value. If not, repeat step (c); if it has recovered, resume the filtration operation.

10. A filtering method according to claim 9, characterized in that, In the step (c), when the self-cleaning step is started, the stirring rod drives the scraper and the support plate to rotate. The auxiliary negative pressure suction device and the main negative pressure suction device are started simultaneously. The auxiliary negative pressure suction device transmits the negative pressure to the first communication cavity, the second communication cavity and the slag discharge cavity through the negative pressure suction pipe to suck the impurities accumulated at the scraper; at the same time, the main negative pressure suction device transmits the negative pressure to the slag discharge pipe and the slag discharge port, and the slag discharge port transmits the negative pressure to the limiting slag discharge cavity, so as to suck the mixed material of the slurry material and impurities at the top of the guiding hopper and the limiting hopper; after the stirring rod rotates 5-10 revolutions, the stirring rod rotates to the position of the blade, and the telescopic rod pushes the blade down. The blade contacts the inner wall of the filter cartridge and the side wall of the scraper to push the impurities remaining on the scraper to the limiting slag discharge cavity.

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