Underground online self-cleaning multistage filtering device

Abstract

The invention discloses an underground online self-cleaning multi-stage filtering device, and aims to overcome the defects that the filtering effect of mine water is poor, and an automatic backwashing function cannot be realized. The device comprises a rough filtration unit, a disc type filtration unit and a bag type filtration unit which are connected in sequence, the disc type filtration unit comprises a plurality of disc type filters connected in parallel, water inlets of the disc type filters are connected with an automatic reversing three-way valve, and the three-way valve is provided with a liquid inlet end, a liquid outlet end and a pollution discharge end; and the three-way valve automatically reverses to realize communication between the liquid inlet end and the liquid outlet end or communication between the liquid outlet end and the pollution discharge end. The underground online self-cleaning multi-stage filtering device has an automatic backwashing function, suspended matters in water are removed step by step through multi-stage filtering, purified water is provided for an underground coal mine, and the problems of scaling, blocking and the like of cooling equipment are effectively relieved.

Description

Technical Field

[0001] The present invention relates to underground water treatment technology in coal mines, and more particularly to an underground online self-cleaning multi-stage filtering device. Background Art

[0002] During coal mine construction and mining, mine water, primarily composed of groundwater, dust control sprinklers, and cooling water for mechanical equipment, contains large amounts of suspended pollutants such as coal dust and rock dust. Directly discharging untreated mine water not only poses significant environmental pollution risks but also results in a double waste of water and mineral resources. Currently, most underground coal mines use a single filtration method or a simple combination of filtration processes to treat mine water. Typical steps include: ① filtering large particulate pollutants using screens, vibrating screens, or other filters; ② directly using high-efficiency fiber filters to remove suspended solids from the water; and ③ installing bag filters in front of the water pump. Problems: ① Each of these methods requires the construction of a separate treatment facility, which occupies a large area and requires dedicated management and maintenance, resulting in high costs; ② The above methods only achieve primary filtration, which cannot meet production needs; and ③ The above methods cannot achieve automatic backwashing and require manual operation. For example, Chinese patent application No. 2011101461444 discloses a dedicated mine water filtration device. This device removes coarse impurities, such as sand, pebbles, or coal dust, through a filter barrel. Harmful substances are separated through a separator, and then finally separated through a solid-liquid separator, resulting in pure mine water. This filtration method offers excellent results. However, this method lacks automatic backwashing.

[0003] These traditional technologies have significant drawbacks, making it difficult to effectively remove suspended solids of varying particle sizes from water. Specifically, a single filtration method can often only filter impurities within a specific particle size range, leaving it powerless against finer suspended solids. While simple combined filtration processes improve filtration effectiveness to a certain extent, their lack of systematicity and specificity still prevents them from meeting the complex water purification needs of underground coal mines. Traditional purification technologies frequently cause scaling and clogging in water-using equipment, reducing equipment efficiency and increasing maintenance costs while also creating the potential for safety incidents caused by equipment failure. Summary of the Invention

[0004] In order to overcome the above-mentioned shortcomings, the present invention provides an underground online self-cleaning multi-stage filtration device, which has an automatic backwashing function. Through multi-stage filtration, it removes suspended matter in the water step by step, provides purified water for coal mines, and effectively alleviates problems such as scaling and blockage of cooling equipment.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: an underground online self-cleaning multi-stage filtration device, comprising a coarse filtration unit, a disc filtration unit and a bag filtration unit connected in sequence, the disc filtration unit comprising a plurality of disc filters connected in parallel, the water inlet of the disc filter being connected to an automatically reversing three-way valve, the three-way valve being provided with a liquid inlet end, a liquid outlet end and a sewage discharge end; the three-way valve automatically reversing to achieve communication between the liquid inlet end and the liquid outlet end, or communication between the liquid outlet end and the sewage discharge end.

[0006] The technical solution of this patent application adopts coarse filtration + disc fine filtration + bag precision filtration process. Through multi-stage purification treatment, it can gradually and significantly remove suspended matter in the water, providing purified water for the tertiary cooling, spray dust suppression or emulsion pumping station, gas extraction pumping station and coal mining machine in the coal mine, thereby alleviating the problems of scaling and blockage of cooling equipment.

[0007] The underground water supply passes through the coarse filtration unit with a filtration accuracy of 200 microns, which removes large particles in the water and can provide water for cooling or spraying of the three machines. A part of it enters the disc filter unit after pressure reduction (0.3~0.5Mpa). The disc filter is an automatic backwash filter, which can achieve large flow and high-precision filtration with a filtration accuracy of 50 microns. In order to further ensure the water output of the laminated filter, a precision bag filter unit is installed at the rear with a filtration accuracy of 5~20 microns. The water output from the precision filter can be used for emulsion proportioning.

[0008] During normal disc filter operation, the three-way valve's liquid inlet and outlet are connected. During automatic backwashing, the three-way valve automatically switches direction, connecting the liquid outlet and the wastewater outlet. Because there are multiple disc filters connected in parallel, water filtered by other disc filters enters the outlet of the disc filter that needs backwashing. After backwashing the disc filter, water flows out of the disc filter's water inlet and is discharged through the wastewater outlet of the three-way valve.

[0009] The underground online self-cleaning multi-stage filtration device of this patent application removes suspended matter in the water step by step through multi-stage filtration, provides purified water for underground coal mines, and effectively alleviates problems such as scaling and clogging of cooling equipment.

[0010] Preferably, a valve cavity is provided in the three-way valve, a movable valve stem is installed in the valve cavity, and an upper valve disc and a lower valve disc are installed on the valve stem; the valve stem moves upward to cause the upper valve disc to close the upper end of the valve cavity, and the liquid outlet end is connected to the sewage outlet end; the valve stem moves downward to cause the lower valve disc to close the lower end of the valve cavity, and the liquid inlet end is connected to the liquid outlet end.

[0011] The reversing operation of the three-way valve is achieved by the movement of the valve stem. When the valve stem moves upward, the upper valve disc closes the upper end of the valve cavity, and the liquid outlet is connected to the sewage outlet. When the valve stem moves downward, the lower valve disc closes the lower end of the valve cavity, and the liquid inlet is connected to the liquid outlet.

[0012] Preferably, a magnetic block is installed on the valve stem, and an electromagnet is installed on the three-way valve. When the electromagnet is energized, the magnetic block is attracted and repelled, thereby realizing the movement of the valve stem.

[0013] Changing the direction of the current in the coil on the electromagnet changes the direction of the electromagnet's magnetic field, which attracts or repels the magnetic block, and thus moves the valve stem. The three-way valve reversing operation is convenient and reliable.

[0014] Preferably, a water pipe is installed between the coarse filtration unit and the disc filtration unit, the liquid inlet ends of the three-way valves are connected to the water pipe, and a pressure regulating valve and a safety valve are installed on the water pipe.

[0015] A pressure regulating valve and a safety valve are installed on the water pipe between the coarse filtration unit and the disc filter unit to facilitate the adjustment of the water pressure. The safety valve can provide overpressure relief protection to prevent damage to the equipment caused by excessive pressure.

[0016] Preferably, the coarse filtration unit includes a coarse filtration filter, which includes an inner cylinder and an outer cylinder, an annular flow channel is formed between the inner cylinder and the outer cylinder, coarse filtration holes are provided on the side wall of the inner cylinder, a liquid inlet is provided on the inner cylinder, and a liquid outlet is provided on the outer cylinder.

[0017] The downhole water is transported into the inner tube from the liquid inlet on the inner tube, and after coarse filtration in the inner tube, it enters the annular flow channel and is discharged outward from the liquid outlet on the outer tube.

[0018] Preferably, the disc filter includes a filter cartridge and multiple filter stacks installed in the filter cartridge. When the filter stacks are stacked, an inner cavity is formed inside, and an outer cavity is formed between the outside of the filter stacks and the filter cartridge. A water inlet and a water outlet are provided on the filter cartridge, and a positioning seat and an abutment spring are installed in the filter cartridge, with the positioning seat being placed between the filter stack and the abutment spring; the water inlet is connected to the outer cavity, and a one-way valve is installed between the water outlet and the inner cavity; a number of flushing pipes are installed in the inner cavity, a number of flushing pores are installed on the flushing pipes, and the flushing pipes are connected to the water outlet.

[0019] When the disc filter is operating, water flows from the water inlet into the outer cavity. The water flows through the gaps between the filter discs, trapping particulate matter on the outer edges of the discs. The filtered water then flows into the inner cavity and, after passing through the one-way valve, is discharged out the water outlet. During backwashing, the three-way valve reverses direction, allowing flushing water to flow from the outlet into the filter cartridge, where it is transported to the flushing pipe and sprayed out through the flushing holes in the flushing pipe onto the filter discs, washing away impurities. The filter discs rotate under the action of the backwash water, ensuring that all impurities are effectively washed and discharged. The flushed water then flows out from the water inlet to the three-way valve and out the wastewater outlet on the three-way valve.

[0020] Preferably, the positioning seat is sleeve-connected to the mounting seat, a pressure storage chamber is formed between the positioning seat and the mounting seat, a flushing pipe is connected to the mounting seat, and the flushing pipe is communicated with the pressure storage chamber.

[0021] During the backwash process, the water in the flushing pipe flows into the pressure accumulation chamber, increasing the pressure in the pressure accumulation chamber and pushing the positioning seat to move, thereby reducing the clamping force of the positioning seat on the filter stack, further loosening the filter stack and improving the flushing effect of the filter stack.

[0022] Preferably, a connecting seat is installed in the filter cartridge, and the flushing pipe is connected to the connecting seat; a flow hole is provided on the connecting seat, and a one-way valve is installed at the flow hole.

[0023] The connecting seat not only facilitates the installation of the flushing pipe, but also facilitates the installation of the one-way valve.

[0024] Preferably, the bag filter unit includes a plurality of bag filters, wherein a fixed mesh cylinder and filter bags are installed in the bag filters, and the filter bags are installed in the fixed mesh cylinder.

[0025] When the bag filter is in use, water flows into the filter bag from the open end, is filtered by the filter bag, and then discharged to the outside, achieving precision filtration. The fixed mesh cylinder plays a role in positioning and protecting the filter bag.

[0026] Preferably, an inlet and an outlet are provided on the bag filter, and an impeller driven by water flow is installed at the inlet of the bag filter. The impeller is connected to a hanging rope, and the hanging rope is connected to an impact ball. The rotation of the impeller drives the impact ball to hit the inner wall of the filter bag.

[0027] Water flows into the bag filter from the inlet, driving the impeller to rotate, thereby driving the impact ball to hit the inner wall of the filter bag, which can slow down the deposition rate of impurities on the inner wall of the filter bag, extend the service life of the filter bag, and reduce the frequency of cleaning the filter bag.

[0028] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The underground online self-cleaning multi-stage filter device of the present patent application has an automatic backwashing function. Through multi-stage filtration, it removes suspended matter in the water step by step, provides purified water for underground coal mines, and effectively alleviates the problems of scaling and clogging of cooling equipment; (2) The disc filter has an automatic backwashing function, which can automatically remove dirt on the filter, extend the service life, and reduce maintenance costs; (3) During the backwashing process, the water flow in the flushing pipe flows into the pressure accumulation chamber, which increases the pressure in the pressure accumulation chamber and pushes the positioning seat to move, thereby reducing the pressing force of the positioning seat on the filter stack, further loosening the filter stack, and improving the flushing effect of the filter stack; (4) The water flow entering the bag filter drives the impeller to rotate, thereby driving the impact ball to swing and hit the inner wall of the filter bag, which can slow down the deposition rate of impurities on the inner wall of the filter bag, extend the service life of the filter bag, and reduce the frequency of cleaning the filter bag. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1It is a structural schematic diagram of the present invention.

[0030] Figure 2 It is another structural schematic diagram of the present invention.

[0031] Figure 3 It is a structural diagram of a coarse filter of the present invention.

[0032] Figure 4 1 is a structural diagram of a disc filter according to embodiments 1, 2, and 3 of the present invention.

[0033] Figure 5 1 is a structural diagram of a bag filter according to embodiment 1 of the present invention.

[0034] Figure 6 It is a filtration state diagram of the disc filter of the present invention.

[0035] Figure 7 It is a backwash state diagram of the disc filter of the present invention.

[0036] Figure 8 It is a structural diagram of a bag filter according to Example 2 of the present invention.

[0037] Figure 9 3 is a structural diagram of a bag filter according to embodiment 3 of the present invention.

[0038] Figure 10 It is a partial structural diagram of a disc filter according to Example 4 of the present invention.

[0039] In the figure: 1, coarse filter unit, 2, disc filter unit, 3, bag filter unit, 4, base, 5, water pipe, 6, pressure regulating valve, 7, safety valve, 8, manual ball valve, 9, disc filter, 10, water inlet, 11, three-way valve, 12, liquid inlet end, 13, liquid outlet end, 14, sewage discharge end, 15, valve chamber, 16, valve stem, 17, upper valve disc, 18, lower valve disc, 19, magnetic block, 20, electromagnet, 21, filter cartridge, 22, filter stack, 23, water outlet, 24, positioning seat, 25, abutment spring, 26, pressure accumulator chamber, 27, top seat, 28, connecting rod, 29, sewage discharge pipe, 30, flow pipe, 31, inner cavity, 32, outer cavity, 33, one-way valve, 34, flushing pipe, 35, flushing pore, 36, connecting seat , 37, flow hole, 38, valve seat, 39, valve body, 40, sealing disc, 41, convex ring, 42, coarse filter, 43, inner cylinder, 44, outer cylinder, 45, annular flow channel, 46, liquid inlet, 47, liquid outlet, 48, bag filter, 49, fixed mesh cylinder, 50, filter bag, 51, inlet, 52, outlet, 53, positioning ring, 54, positioning sleeve, 55, positioning frame, 56, pressure plate, 57, flange, 58, impeller, 59, mounting shaft, 60, lifting rope, 61, impact ball, 62, ring groove, 63, convex ring, 64, push-pull rod, 65, support, 66, pressure relief hole, 67, step sealing surface, 68, pressure relief plate, 69, inner push rod, 70, outer push rod, 71, positioning mesh plate, 72, slide rod, 73, mounting seat. DETAILED DESCRIPTION

[0040] The technical solution of the present invention is further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example 1: An underground online self-cleaning multi-stage filter device (see Figures 1 to 7 ), comprising a coarse filtration unit 1, a disc filtration unit 2 and a bag filtration unit 3 connected in sequence, wherein the coarse filtration unit 1, the disc filtration unit 2 and the bag filtration unit 3 are all mounted on a base 4. A water supply pipe 5 is installed between the coarse filtration unit 1 and the disc filtration unit 2. A pressure regulating valve 6 and a safety valve 7 are installed on the water supply pipe 5, and a manual ball valve 8 is installed on the water supply pipe 5, wherein the pressure regulating valve 6 is installed between the manual ball valve 8 and the safety valve 7. Multiple water diversion joints are installed on the water supply pipe 5 to facilitate water diversion. The pressure regulating valve 6 facilitates the adjustment of the water pressure, and the safety valve 7 can provide overpressure relief protection to prevent damage to the equipment caused by excessive pressure.

[0041] The disc filter unit 2 includes a plurality of disc filters 9 connected in parallel. The number of the disc filters 9 can be adjusted as needed. Figure 1 As shown, five disc filters 9 are provided. Figure 2As shown, three disc filters 9 are provided. The water inlet 10 of each disc filter 9 is connected to an automatically reversing three-way valve 11. Each disc filter 9 is individually connected to a three-way valve 11. The three-way valve 11 has a liquid inlet 12, a liquid outlet 13, and a wastewater outlet 14. The liquid inlet 12 of each three-way valve 11 is connected to the water pipe 5. The three-way valve 11 automatically reversibly connects the liquid inlet 12 to the liquid outlet 13, or vice versa.

[0042] A valve chamber 15 is disposed within the three-way valve 11. The liquid inlet 12 communicates with the upper portion of the valve chamber 15, the liquid outlet 13 communicates with the middle portion of the valve chamber 15, and the sewage outlet 14 communicates with the lower portion of the valve chamber 15. A movable valve stem 16 is mounted within the valve chamber 15, with an upper valve disc 17 and a lower valve disc 18 mounted on the valve stem 16. When the valve stem 16 moves upward, the upper valve disc 17 closes the upper portion of the valve chamber 15, connecting the liquid outlet 13 with the sewage outlet 14. When the valve stem 16 moves downward, the lower valve disc 18 closes the lower portion of the valve chamber 15, connecting the liquid inlet 12 with the liquid outlet 13. A magnet 19 is mounted on the valve stem 16, and an electromagnet 20 is mounted on the three-way valve 11. When electromagnet 20 is energized, it attracts or repels magnet 19, thereby moving the valve stem 16. Changing the direction of the current flowing in the coil of electromagnet 20 changes the direction of the electromagnet's magnetic field, attracting or repelling magnet 19, thereby moving the valve stem 16. The reversing operation of the three-way valve 11 is convenient and reliable.

[0043] The disc filter 9 includes a filter cartridge 21 and a plurality of filter stacks 22 mounted within the cartridge 21. The filter stacks 22 are annular in structure and are densely covered with multiple grooves on both surfaces. When stacked, the stacks 22 form an inner cavity 31, and an outer cavity 32 is formed between the outer portions of the filter stacks 22 and the cartridge 21. The cartridge 21 is provided with a water inlet 10 and a water outlet 23. A positioning seat 24 and an abutment spring 25 are mounted within the cartridge 21, positioned between the filter stacks 22 and the abutment spring 25. The positioning seat 24 is fittedly connected to the mounting seat 73, with a pressure accumulator chamber 26 formed between the positioning seat 24 and the mounting seat 73. A top seat 27 is provided at the top end of the filter cartridge 21, and a connecting rod 28 is provided on the top seat 27. The positioning seat 24 is sealed and fitted with the connecting rod 28. The abutment spring 25 is fitted onto the connecting rod 28, and the upper end of the abutment spring 25 abuts against the top seat 27. The connecting rod 28 is tightly connected to the mounting seat 73, and the positioning seat 24 is fitted outside the mounting seat 73. A drain pipe 29 and a flow pipe 30 are mounted on the base 4. The drain end 14 of the three-way valve 11 is connected to the drain pipe 29, and the water outlet 23 on the filter cartridge 21 is connected to the flow pipe 30.

[0044] The water inlet 10 on the filter cartridge 21 communicates with the outer chamber 32, and a one-way valve 33 is installed between the water outlet 23 and the inner chamber 31. Several flushing pipes 34 are installed within the inner chamber 31, each equipped with a plurality of flushing holes 35. These holes 35 face tangentially to the filter stack 22, connecting the flushing pipes 34 and the water outlet 23. A connecting seat 36 is installed within the filter cartridge 21, and the lower end of the flushing pipe 34 is connected to the connecting seat 36. The connecting seat 36 is provided with a flow hole 37, and the one-way valve 33 is installed in this flow hole 37. The upper end of the flushing pipe 34 is connected to the mounting seat 73, connecting the flushing pipe 34 to the pressure accumulation chamber 26. The one-way valve 33 comprises a valve seat 38 and a valve body 39. The valve body 39 is mounted on the valve seat 38 for vertical movement. A sealing disc 40 is installed on the valve body 39, and a raised ring 41 is provided on the inner wall of the flow hole 37. The sealing disc 40 covers the raised ring 41 to achieve a seal.

[0045] The transition unit of the disc filter 9 is constructed by stacking filter laminations 22 with grooves in different directions on both sides. The groove edges on the adjacent surfaces form numerous intersections, which form a large number of cavities and irregular pathways that continuously shrink from the outside to the inside. During filtration, these pathways cause turbulence in the water, ultimately causing impurities in the water to be intercepted at the various intersections. Under the action of the abutment spring 25 and the pressure of the incoming water, a filter unit is formed that is loose on the outside and tight on the inside. The laminations in each filter unit, compressed by the abutment spring 25 and the water pressure, form countless filter screens that impurity particles cannot pass through. The width of the filter laminations 22 is 12-14 mm.

[0046] Backwash water flows tangentially along the inner wall of the filter stack 22, flushing impurities from the inside out. The stack rotates under the influence of the backwash water, ensuring that all impurities are effectively washed and discharged. All backwash steps can be controlled using the outlet water quality and pressure differential. Once set, this system can be used continuously. Automatic backwash filters complete the entire backwash process in seconds without interruption. Filters employing this filtration principle dynamically adjust the gap between the stacks 22 during filtration and backwashing, significantly improving filtration performance and filtered water quality while significantly reducing backwash water consumption, typically by approximately 0.25%. The depth and number of grooves in the stack 22 determine the filter unit's filtration accuracy, which can reach 20 to 100 microns.

[0047] The coarse filtration unit 1 includes a coarse filter 42, which comprises an inner cylinder 43 and an outer cylinder 44. An annular flow channel 45 is formed between the inner and outer cylinders 43 and 44. Coarse filtration holes are provided on the sidewall of the inner cylinder 43. A liquid inlet 46 is provided on the inner cylinder 43, and a liquid outlet 47 is provided on the outer cylinder 44. The liquid inlet 46 is located at the top of the coarse filter 42, while the liquid outlet 47 is located at the bottom of the coarse filter 42. Downhole water is pumped into the inner cylinder 43 through the liquid inlet 46. After coarse filtration by the inner cylinder 43, it enters the annular flow channel 45 and is discharged through the liquid outlet 47 on the outer cylinder 44.

[0048] The bag filter unit 3 includes several bag filters 48, and the number of bag filters 48 is adjusted as needed. Figure 1 As shown, there are three bag filters 48. Figure 2 As shown, there is one bag filter 48. A fixed mesh cylinder 49 with an open top and a filter bag 50 are installed within the bag filter 48. The filter bag 50 is mounted within the fixed mesh cylinder 49. The bag filter 48 is provided with an inlet 51 and an outlet 52. The inlet 51 is connected to the flow pipe 30, and the outlet 52 is connected to the outlet pipe. The inlet 51 is located at the top of the bag filter 48, and the outlet 52 is located at the bottom of the bag filter 48. A positioning ring 53 is provided at the top of the fixed mesh cylinder 49. A positioning sleeve 54 with a flange 57 is provided at the top of the filter bag 50. The flange 57 is supported on the positioning ring 53. The top of the bag filter 48 is connected to a positioning frame 55. The bottom of the positioning frame 55 is provided with an annular pressure plate 56, which is pressed against the flange 57. A sealing ring is installed between the pressure plate 56 and the flange 57. Water flows into the filter bag 50 from the open end, is filtered by the filter bag 50, and is discharged to the outside, thereby achieving precision filtration.

[0049] The technical solution of this patent application adopts coarse filtration + disc fine filtration + bag precision filtration process. Through multi-stage purification treatment, it can gradually and significantly remove suspended matter in the water, providing purified water for the tertiary cooling, spray dust suppression or emulsion pumping station, gas extraction pumping station and coal mining machine in the coal mine, thereby alleviating the problems of scaling and blockage of cooling equipment.

[0050] The underground water supply passes through the coarse filtration unit 1 with a filtration accuracy of 200 microns, which removes large particles in the water and can provide water for cooling or spraying of the three machines. A part of it enters the disc filter unit 2 after being reduced in pressure (0.3~0.5Mpa). The disc filter 9 is an automatic backwash filter, which realizes large flow and high-precision filtration with a filtration accuracy of 50 microns. In order to further ensure the water output of the laminated filter, a precision bag filter unit 3 is installed at the rear with a filtration accuracy of 5~20 microns. The water output from the precision filter can be used for emulsion proportioning.

[0051] When the disc filter 9 is operating, water flows from the water inlet 10 into the outer cavity 32. The water flows through the gaps between the filter stacks 22, blocking particulate matter outside the filter stacks 22. The filtered water flows into the inner cavity 31 and passes through the one-way valve 33 before being discharged from the water outlet 23. During backwashing, the three-way valve 11 is reversed, and flushing water flows from the water outlet 23 into the filter cartridge 21. It is then transported to the flushing pipe 34 and sprayed out from the flushing holes 35 on the flushing pipe 34 onto the filter stacks 22, flushing impurities from the filter stacks 22. The filter stacks 22 rotate under the action of the backwash water, ensuring that all impurities are effectively washed and discharged. The flushed water flows from the water inlet 10 to the three-way valve 11 and is discharged from the sewage outlet 14 on the three-way valve 11.

[0052] Example 2: An underground online self-cleaning multi-stage filter device (see Figure 8 ), its structure is similar to that of embodiment 1, the main difference being the structure of the bag filter unit 3. In this embodiment, the bag filter unit 3 includes a plurality of bag filters 48, the number of which is adjusted as needed, such as Figure 1 As shown, there are three bag filters 48. Figure 2 As shown, there is one bag filter 48. A fixed mesh cylinder 49 with an open top and a filter bag 50 are installed within the bag filter 48. The filter bag 50 is mounted within the fixed mesh cylinder 49. The bag filter 48 is provided with an inlet 51 and an outlet 52. The inlet 51 is connected to the flow pipe 30, and the outlet 52 is connected to the outlet pipe. The inlet 51 is located at the top of the bag filter 48, and the outlet 52 is located at the bottom of the bag filter 48. A positioning ring 53 is provided at the top of the fixed mesh cylinder 49. A positioning sleeve 54 with a flange 57 is provided at the top of the filter bag 50. The flange 57 is supported on the positioning ring 53. The top of the bag filter 48 is connected to a positioning frame 55. The bottom of the positioning frame 55 is provided with an annular pressure plate 56, which is pressed against the flange 57. A sealing ring is installed between the pressure plate 56 and the flange 57. Water flows into the filter bag 50 through its open end, passes through the filter bag 50, and is then discharged to achieve precision filtration. An impeller 58 driven by the water flow is installed at the inlet 51 of the bag filter 48. A mounting shaft 59 is provided on the positioning frame 55. The impeller 58 is rotatably mounted on the mounting shaft 59. Several blades are evenly distributed circumferentially on the impeller 58. The impeller 58 is connected to a hanging rope 60, which is connected to an impact ball 61. The impact ball 61 is placed in the filter bag 50. The rotation of the impeller 58 drives the impact ball 61 to impact the inner wall of the filter bag 50.

[0053] Water flows into the bag filter 48 from the inlet 51, driving the impeller 58 to rotate, thereby driving the impact balls 61 to impact the inner wall of the filter bag 50. This can slow the deposition rate of impurities on the inner wall of the filter bag 50, extend the service life of the filter bag 50, and reduce the frequency of cleaning the filter bag 50. The other structures are the same as those in Example 1.

[0054] Example 3: An underground online self-cleaning multi-stage filter device (see Figure 9 ), its structure is similar to that of embodiment 1, the main difference being the structure of the bag filter unit 3. In this embodiment, the bag filter unit 3 includes a plurality of bag filters 48, the number of which is adjusted as needed, such as Figure 1 As shown, there are three bag filters 48. Figure 2 As shown, there is one bag filter 48. A fixed mesh cylinder 49 with an open top and a filter bag 50 are installed within the bag filter 48. The filter bag 50 is mounted within the fixed mesh cylinder 49. The bag filter 48 is provided with an inlet 51 and an outlet 52. The inlet 51 is connected to the flow pipe 30, and the outlet 52 is connected to the outlet pipe. The inlet 51 is located at the top of the bag filter 48, and the outlet 52 is located at the bottom of the bag filter 48. A positioning ring 53 is connected to the top of the fixed mesh cylinder 49. A positioning sleeve 54 with a flange 57 is provided at the top of the filter bag 50. The flange 57 is supported on the positioning ring 53. A positioning frame 55 is connected to the top of the bag filter 48. An annular pressure plate 56 is provided at the bottom of the positioning frame 55. The pressure plate 56 is pressed against the flange 57, and a sealing ring is installed between the pressure plate 56 and the flange 57. Water flows into the filter bag 50 from the open end, is filtered by the filter bag 50, and is discharged to the outside, thereby achieving precision filtration.

[0055] An annular groove 62 is provided on the positioning ring 53, and an outwardly extending protruding ring 63 is provided on the upper edge of the fixed mesh cylinder 49. The protruding ring 63 is mounted in the annular groove 62 and can slide in the annular groove 62. The outer diameter of the protruding ring 63 is smaller than the bottom diameter of the annular groove 62. The annular groove 62 is provided at the lower portion of the positioning ring 53. An impeller 58 driven by the water flow is installed at the inlet 51 of the bag filter 48. A mounting shaft 59 is provided on the positioning frame 55. The impeller 58 is rotatably mounted on the mounting shaft 59. The impeller 58 has a plurality of blades evenly distributed circumferentially. The impeller 58 is rotatably connected to a push-pull rod 64, which is rotatably connected to a support 65. The support 65 presses on the filter bag 50 and is tightly connected to the fixed mesh cylinder 49.

[0056] Water flows into the bag filter 48 from the inlet 51, driving the impeller 58 to rotate, thereby driving the fixed mesh cylinder 49 to shake laterally through the push-pull rod 64. This makes it difficult for impurities to quickly remain on the inner wall of the filter bag 50, thereby extending the service life of the filter bag 50 and reducing the frequency of cleaning the filter bag 50. The other structures are the same as those in Example 1.

[0057] Example 4: An underground online self-cleaning multi-stage filter device (see Figure 10), its structure is similar to any of Examples 1, 2, and 3, with the main difference being the structure of the disc filter 9. In this embodiment, the disc filter 9 includes a filter cartridge 21 and a plurality of filter stacks 22 mounted within the filter cartridge 21. The filter stacks 22 are annular in structure, with multiple grooves densely distributed on both surfaces. When stacked, the filter stacks 22 form an inner cavity 31, and an outer cavity 32 is formed between the outer portions of the filter stacks 22 and the filter cartridge 21. The filter cartridge 21 is provided with a water inlet 10 and a water outlet 23. A positioning seat 24 and an abutment spring 25 are mounted within the filter cartridge 21, with the positioning seat 24 positioned between the filter stacks 22 and the abutment spring 25. The positioning seat 24 is fittedly connected to the mounting seat 73, with a pressure accumulation chamber 26 formed between the positioning seat 24 and the mounting seat 73. A pressure relief hole 66 is provided on the positioning seat 24, and a stepped sealing surface 67 is provided in the pressure relief hole 66. A movably mounted pressure relief plate 68 is installed in the pressure relief hole 66. The pressure relief plate 68 is pressed against the stepped sealing surface 67, thereby sealing the pressure relief hole 66. An inner push rod 69 is provided on the mounting seat 73, and an outer push rod 70 is provided in the filter cartridge 21. Both the inner push rod 69 and the outer push rod 70 can push open the pressure relief plate 68, and a gap is provided between the outer push rod 70 and the pressure relief plate 68. A positioning mesh plate 71 is installed at the open end of the pressure relief hole 66, and a socket is provided in the middle of the positioning mesh plate 71. A slide rod 72 is provided on the pressure relief plate 68, and the slide rod 72 is movably connected to the socket, thereby enabling the pressure relief plate 68 to be installed and slide smoothly. A top seat 27 is provided at the top end of the filter cartridge 21, an outer push rod 70 is mounted on the top seat 27, a connecting rod 28 is mounted on the top seat 27, a positioning seat 24 is sealingly connected to the connecting rod 28, an abutting spring 25 is mounted on the connecting rod 28, the upper end of the abutting spring 25 abuts against the top seat 27, the connecting rod 28 is tightly connected to the mounting seat 73, and the positioning seat 24 is mounted outside the mounting seat 73. A drain pipe 29 and a flow pipe 30 are mounted on the base 4. The drain end 14 of the three-way valve 11 is connected to the drain pipe 29, and the water outlet 23 on the filter cartridge 21 is connected to the flow pipe 30.

[0058] When the disc filter 9 is operating, water flows from the water inlet 10 into the outer cavity 32. The water flows through the gaps between the filter stacks 22, blocking particulate matter outside the filter stacks 22. The filtered water flows into the inner cavity 31 and passes through the one-way valve 33 before being discharged from the water outlet 23. During backwashing, the three-way valve 11 is reversed, and flushing water flows from the water outlet 23 into the filter cartridge 21. It is then transported to the flushing pipe 34 and sprayed out from the flushing holes 35 on the flushing pipe 34 onto the filter stacks 22, flushing impurities from the filter stacks 22. The filter stacks 22 rotate under the action of the backwash water, ensuring that all impurities are effectively washed and discharged. The flushed water flows from the water inlet 10 to the three-way valve 11 and is discharged from the sewage outlet 14 on the three-way valve 11. During backwashing, water in the flushing pipe 34 flows into the pressure accumulator chamber 26, increasing the pressure within the pressure accumulator chamber 26 and pushing the retaining seat 24 to move. This reduces the pressure applied by the retaining seat 24 to the filter stack 22, further loosening the filter stack 22 and improving the flushing effect on the filter stack 22. When the pressure relief plate 68 contacts the outer push rod 70, it is pushed away from the stepped sealing surface 67, thereby opening the pressure relief hole 66 and relieving the pressure in the pressure accumulator chamber 26. The retaining seat 24 returns to its original position under the action of the abutment spring 25, pushing the filter stack 22 to move. When the pressure relief plate 68 contacts the inner push rod 69, it is pushed toward the stepped sealing surface 67, thereby closing the pressure relief hole 66. As flushing continues, the pressure within the pressure accumulator chamber 26 increases again, pushing the retaining seat 24 to move, thereby reducing the pressure applied by the retaining seat 24 to the filter stack 22 and further loosening the filter stack 22. This reciprocating motion makes the positioning seat 24 have a shaking effect, thereby improving the shaking effect of the filter stack 22, which is beneficial to improving the flushing effect. The other structures are the same as those of embodiment 1, 2 or 3.

[0059] The above-described embodiments are only preferred solutions of the present invention and are not intended to limit the present invention in any form. Other variations and modifications are possible without exceeding the technical solutions described in the claims.

Claims

1. An underground online self-cleaning multi-stage filter device, characterized in that: It includes a coarse filtration unit, a disc filtration unit and a bag filtration unit connected in sequence. The disc filtration unit includes multiple disc filters connected in parallel. The water inlet of the disc filter is connected to an automatically reversing three-way valve. The three-way valve is provided with a liquid inlet end, a liquid outlet end and a sewage discharge end. The three-way valve automatically reversing realizes the connection between the liquid inlet end and the liquid outlet end, or the connection between the liquid outlet end and the sewage discharge end.

2. The downhole online self-cleaning multi-stage filtering device according to claim 1 is characterized in that the three-way A valve cavity is provided in the valve, a movable valve stem is installed in the valve cavity, and an upper valve disc and a lower valve disc are installed on the valve stem; when the valve stem moves upward, the upper valve disc closes the upper end of the valve cavity, and the liquid outlet end is connected with the sewage outlet end; when the valve stem moves downward, the lower valve disc closes the lower end of the valve cavity, and the liquid inlet end is connected with the liquid outlet end.

3. The downhole online self-cleaning multi-stage filtering device according to claim 2, characterized in that: A magnetic block is installed on the valve stem, and an electromagnet is installed on the three-way valve. When the electromagnet is energized, the magnetic block is attracted and repelled, thereby realizing the movement of the valve stem.

4. The downhole online self-cleaning multi-stage filtering device according to claim 1, characterized in that: A water pipe is installed between the coarse filter unit and the disc filter unit, the liquid inlet end of the three-way valve is connected to the water pipe, and a pressure regulating valve and a safety valve are installed on the water pipe.

5. The downhole online self-cleaning multi-stage filtering device according to claim 1, characterized in that: The coarse filtration unit includes a coarse filtration filter, which includes an inner cylinder and an outer cylinder. An annular flow channel is formed between the inner cylinder and the outer cylinder. Coarse filtration holes are arranged on the side wall of the inner cylinder, a liquid inlet is arranged on the inner cylinder, and a liquid outlet is arranged on the outer cylinder.

6. The downhole online self-cleaning multi-stage filtering device according to claim 1, characterized in that: The disc filter includes a filter cartridge and multiple filter stacks installed in the filter cartridge. An inner cavity is formed when the filter stacks are stacked, and an outer cavity is formed between the outside of the filter stacks and the filter cartridge. A water inlet and a water outlet are provided on the filter cartridge. A positioning seat and an abutment spring are installed in the filter cartridge, and the positioning seat is placed between the filter stack and the abutment spring; the water inlet is connected to the outer cavity, and a one-way valve is installed between the water outlet and the inner cavity; a number of flushing pipes are installed in the inner cavity, a number of flushing pores are installed on the flushing pipes, and the flushing pipes are connected to the water outlet.

7. The downhole online self-cleaning multi-stage filtering device according to claim 6, characterized in that: The positioning seat is connected to the mounting seat in a sleeve, a pressure storage chamber is formed between the positioning seat and the mounting seat, a flushing pipe is connected to the mounting seat, and the flushing pipe is communicated with the pressure storage chamber.

8. The downhole online self-cleaning multi-stage filtering device according to claim 6, characterized in that: A connecting seat is installed in the filter cartridge, and the flushing pipe is connected to the connecting seat; a flow hole is provided on the connecting seat, and a one-way valve is installed at the flow hole.

9. The downhole online self-cleaning multi-stage filter device according to any one of claims 1 to 8, characterized in that: The bag filter unit includes several bag filters, a fixed mesh cylinder and filter bags are installed in the bag filters, and the filter bags are installed in the fixed mesh cylinder.

10. The downhole online self-cleaning multi-stage filtering device according to claim 9, characterized in that: An inlet and an outlet are provided on the bag filter. An impeller driven by water flow is installed at the inlet of the bag filter. The impeller is connected to a hanging rope, which is connected to an impact ball. The rotation of the impeller drives the impact ball to hit the inner wall of the filter bag.

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