Fluid filtering structure and stop valve with same

Abstract

The invention discloses a fluid filtering structure and a stop valve with the filtering structure, and relates to the field of valves.The fluid filtering structure comprises a shell, a cylindrical filter element is fixed in the shell, a filtering area and a backflow area are arranged on the cylindrical filter element, a pressure sensing mechanism is arranged on the cylindrical filter element, and a movable cover is arranged in the cylindrical filter element in a sliding mode; a first through hole is formed in the bottom of the movable cover, a fixing plate is further fixed to the inner side of the cylindrical filter element, a second through hole is formed in the fixing plate, a transmission mechanism is arranged between the movable cover and the pressure sensing mechanism, a blow-off pipe is fixed to the outer side of the filter area, and an automatic communication mechanism is arranged on the blow-off pipe. And one end of the blow-off pipe penetrates through the shell and is connected with a collecting mechanism. When the filtering area is blocked, filtering is carried out through the backflow area, the filtered fluid is used for carrying out back flushing on the filtering area, blockages are collected in the collecting barrel, the barrel-shaped filter element can be cleaned without stopping conveying, the conveying efficiency can be improved, and actual production requirements are met.

Description

Technical Field

[0001] This application relates to the field of valves, and more particularly to a fluid filtration structure and a shut-off valve having the filtration structure. Background Art

[0002] Filtration in liquefied natural gas (LNG) transportation pipelines is of great significance. It not only protects the pipeline system, preventing impurities from wearing down and corroding the pipeline's inner walls, avoiding pipeline blockages, and extending its service life, but also protects equipment along the pipeline such as valves, pumps, and flow meters, reducing the frequency of failures and maintenance, and lowering operating costs. At the same time, it ensures LNG quality, prevents external impurities from mixing in to meet users' quality requirements, and improves safety by reducing safety hazards such as chemical reactions and static electricity buildup caused by impurities, thus preventing accidents such as fires and explosions.

[0003] A search revealed a Chinese patent document disclosing a filter and filtration system [Application No.: CN202411605857.6; Publication No.: CN119139778A]. This filter includes a cylinder and upper and lower cover plates detachably installed at the upper and lower ends of the cylinder. The filter element assembly includes a first filter element and a second filter element. The first filter element is installed into the cavity from bottom to top, and the second filter element is installed into the cavity from top to bottom, with the lower end of the second filter element extending into the interior of the first filter element. The filter forms a sequentially connected lower interface, a first fluid channel, a second fluid channel, a third fluid channel, and an upper interface. A pressure tap connected to the second fluid channel is also formed on the housing. Although it can achieve step-by-step filtration, and the first and second filter elements are separately set and can be independently disassembled and installed without interference, making disassembly and installation more convenient and enabling precise replacement, the above device still requires stopping the delivery of liquefied natural gas when replacing the filter element, reducing the delivery efficiency and hindering actual production needs. Summary of the Invention

[0004] To achieve uninterrupted transportation of liquefied natural gas, this application provides a fluid filtration structure and a shut-off valve having the filtration structure.

[0005] The fluid filtration structure and the shut-off valve having the filtration structure provided in this application adopt the following technical solution:

[0006] A fluid filtration structure includes a housing with an inlet and an outlet connected to its two ends. A cylindrical filter element with an end seal is fixed inside the housing near the inlet. The cylindrical filter element has a filtration zone and a backflow zone. The sealed end of the cylindrical filter element is equipped with a pressure sensing mechanism for sensing internal and external pressure. A movable cover with an open end is slidably disposed inside the cylindrical filter element, located inside the backflow zone. The bottom of the movable cover has several first through holes. A fixing plate is also fixed inside the cylindrical filter element, and the fixing plate has several second through holes that branch off from the first through holes. The fixing plate is located between the pressure sensing mechanism and the movable cover. A transmission mechanism for moving the movable cover is provided between the movable cover and the pressure sensing mechanism. A drain pipe is fixed outside the filtration zone, and the drain pipe has an automatic connection mechanism. The end of the drain pipe away from the cylindrical filter element passes through the housing and is connected to a collection mechanism. The collection mechanism includes a replaceable collection cylinder, which is threadedly connected to the drain pipe.

[0007] By adopting the above technical solution, the fluid enters from the inlet, passes through the first and second through holes, and then flows out from the cylindrical filter element, achieving a filtration effect. Finally, it is discharged from the outlet. When the filtration zone of the cylindrical filter element becomes clogged, it causes a pressure difference between the inside and outside of the filter element. When the pressure difference reaches a certain standard, the pressure sensing mechanism will drive the moving cover to move closer to the fixed plate via the transmission mechanism, causing the moving cover to adhere to the fixed plate. At this time, the first and second through holes are separated and sealed. Simultaneously, the pressure sensing mechanism will also drive the automatic connection mechanism to open the drain pipe. At this point, the fluid flows from the backflow zone to the cylindrical filter element. The fluid flows outside the filter element, with a portion exiting from the outlet and the other portion flowing from the outside to the inside of the filtration zone, backwashing the filtration zone. Finally, it carries away blockages through the drain pipe into the collection cylinder. After collection, the pressure sensing mechanism resets, causing the moving cover and automatic connection mechanism to reset as well. The fluid can then pass through the first and second through holes again and flow out of the filtration zone, while the blockages are collected in the collection cylinder. Operators only need to replace the collection cylinder; cleaning of the cylindrical filter element can be achieved without stopping the conveying process, thus preventing clogging and improving conveying efficiency, which is beneficial for actual production needs.

[0008] Preferably, the pressure sensing mechanism includes a fixed sleeve fixed to the sealing end of the cylindrical filter element, with openings at both ends of the fixed sleeve. A movable piston is slidably disposed on the inner side of the fixed sleeve. An elongated groove is formed on the inner wall of the fixed sleeve, and a boss is provided at the bottom of the groove. A recessed hole is formed on the side wall of the movable piston. A push rod is slidably disposed in the recessed hole. A pressure spring is provided inside the recessed hole. The two ends of the pressure spring abut against the bottom of the recessed hole and the push rod, respectively, and the outer end of the push rod is located in the elongated groove.

[0009] By adopting the above technical solution, when the filtration zone is blocked, the pressure inside the cylindrical filter element is higher than the pressure inside the shell. At this time, the moving piston will move outward under the pressure. However, under the action of the top pressure spring, the push rod is pressed against the bottom of the long groove and blocked by the boss. When the pressure difference reaches a certain standard, the top pressure spring is compressed and the push rod passes over the boss. At this time, the moving piston will move directly to the outermost side.

[0010] Preferably, the transmission mechanism includes a straight rod fixed to the end of the movable piston, two retaining rings fixed on the straight rod, a plurality of connecting rods fixed on the movable cover, the connecting rods passing through the second through holes at corresponding positions, and a ring fixed at the end of the connecting rod away from the movable cover, the straight rod passing through the middle of the ring, and the two retaining rings being located on both sides of the two rings respectively, the outer diameter of the retaining rings being larger than the inner diameter of the rings.

[0011] By adopting the above technical solution, when the moving piston moves outward under the action of pressure difference, the straight rod will pull the ring to move synchronously through the retaining ring. When the ring moves through the straight rod, the moving cover will fit with the fixed plate, thereby sealing the first and second through holes and opening the backflow zone.

[0012] Preferably, the automatic connection mechanism includes two connecting blocks fixed on both sides of the sewage pipe, and a slid groove is opened in the middle of the sewage pipe, which divides the sewage pipe into upper and lower parts, and the upper and lower parts of the sewage pipe are fixedly connected by the connecting blocks. A movable plate is slidably arranged in the slid groove, and a connecting hole is opened at one end of the movable plate near the movable cover. A bent rod is fixed at the other end of the movable plate, and the other end of the bent rod is connected to the end of the movable piston.

[0013] By adopting the above technical solution, the movable plate is inserted into the drain pipe to isolate the drain pipe and prevent fluid from flowing through the drain pipe. When the movable piston moves outward under the action of pressure difference, the bent rod will drive the movable plate to move and make the connecting hole move to align with the drain pipe. At this time, the drain pipe can be opened and the blockage can flow through the drain pipe into the collection cylinder.

[0014] Preferably, the collection mechanism further includes a sealing piston slidably disposed inside the collection cylinder. The upper end of the collection cylinder is provided with a notch, and the collection cylinder is threadedly connected to the sewage pipe through the notch. A one-way liquid inlet valve is connected to the inner side of the notch. A vertical rod is slidably disposed in the middle position of the sealing piston, and a circular plate is fixed at the upper end of the vertical rod. A tension spring is connected between the circular plate and the sealing piston. The bottom of the collection cylinder is provided with a sliding hole and several vent holes. The bottom of the vertical rod is inserted into the sliding hole, and several outwardly extending pieces are provided at the bottom of the vertical rod. The lower ends of the outwardly extending pieces abut against the inner wall of the collection cylinder. Two symmetrically distributed sliding rods are slidably inserted into the shell. The ends of the two sliding rods located inside the shell are connected to each other by a crossbar, and the ends of the two sliding rods located outside the shell are connected to each other by a push plate. A triangular extrusion plate is fixed on the bent rod, and the crossbar is located directly above the triangular extrusion plate.

[0015] By adopting the above technical solution, when the moving piston moves outward under the action of pressure difference, the bent rod will drive the triangular extrusion plate to move, and the inclined surface of the triangular extrusion plate will push the horizontal bar and the sliding bar to move upward, thereby lifting the push plate. The collection cylinder is connected to the drain pipe by threads. When the automatic connection mechanism is opened, the blockage flows into the collection cylinder through the drain pipe and passes through the one-way liquid inlet valve. At this time, the pressure in the collection cylinder gradually increases and pushes the sealing piston downward. However, the vertical rod is blocked by the outward expansion plate and cannot move synchronously with the sealing piston. Therefore, the tension spring will be stretched. When the sealing piston moves to the position of the outward expansion plate, it will squeeze the outward expansion plate inward, so that the vertical rod can move downward. Under the action of the tension spring, the vertical rod will move downward quickly and squeeze the lifted push plate, thereby driving the sliding bar to move downward. The bent rod is reset through the horizontal bar and the triangular extrusion plate, and then the moving piston is reset through the bent rod. At the same time, the moving piston will also drive the moving cover to reset through the connecting rod and the straight rod, realizing all-round automatic reset and facilitating the cyclic use of the cleaning function.

[0016] Preferably, a one-way filling valve is connected to the drain pipe, and the one-way filling valve is located on the outside of the housing.

[0017] By adopting the above technical solution, when transporting hazardous fluids such as liquefied natural gas, before replacing the collection cylinder, a filling device can be used first to fill the drain pipe with safe filling fluid through a one-way filling valve, so that the residual hazardous fluid is fully squeezed into the collection cylinder, and then the collection cylinder can be removed, making the operation safer.

[0018] A shut-off valve includes a valve seat, a connecting seat, and a top cover. The valve seat has an inlet channel and an outlet channel on its two sides, with a connecting channel between them. The connecting seat is bolted to the upper end of the valve seat. A bushing is provided on the upper inner side of the connecting seat, and a valve stem is slidably inserted between the bushing and the connecting seat. An elastic pipe is fitted on the outer side of the valve stem, with its upper end sealed to the bushing and its lower end sealed to the outer wall of the valve stem. A valve disc is connected to the lower end of the valve stem. The top cover is located above the connecting seat and is connected to the connecting seat via an extension screw. An adjusting screw is threaded into the middle of the top cover, and a handwheel is fixed to the upper end of the adjusting screw. The adjusting screw is connected to the valve stem via a connector.

[0019] By adopting the above technical solution, rotating the handwheel drives the adjusting screw to move up and down. Under the action of the connecting part, the valve stem moves synchronously. When the valve stem rises, it can separate the valve disc from the connecting flow channel and open the shut-off valve. When the valve stem falls, it can press the valve disc against the edge of the connecting flow channel and close the shut-off valve. Moreover, when the valve stem moves up and down, the elastic pipe can cooperate with the rise and fall of the valve stem, and both ends of the elastic pipe are sealed, which can achieve a good sealing effect.

[0020] Preferably, the inner side of the bushing is provided with a packing cavity, and the packing cavity is filled with sealing packing. The upper end of the sealing packing is provided with a pressure sleeve, and the two sides of the pressure sleeve are connected to the outside of the connecting seat by bolts.

[0021] By adopting the above technical solution, the pressure sleeve compacts the sealing packing into the packing cavity, which further improves the sealing effect without affecting the valve stem's lifting and lowering, thus achieving a two-stage sealing effect.

[0022] Preferably, the valve stem has a flat groove on its outer side and a flange is provided on the bottom of the inner side of the bushing. The flange matches the flat groove. The connector includes two clamps connected by bolts. The bottom of the adjusting screw and the top of the valve stem are both provided with connectors. The two connectors are located between the two clamps and can rotate relative to each other.

[0023] By adopting the above technical solution, the valve stem cannot rotate under the action of the flange. The adjusting screw and the valve stem are connected by two clamps, which can realize power transmission during the lifting process, but not rotational power transmission. When the adjusting screw lifts and rotates, the valve stem will only move up and down, which can prevent the elastic pipe from twisting and extend its service life.

[0024] In summary, this application includes at least one of the following beneficial technical effects:

[0025] 1. Using a pressure sensing mechanism, the pressure difference inside and outside the cylindrical filter element is determined, and the cylindrical filter element is divided into a filtration zone and a backflow zone. When the filtration zone is blocked, the backflow zone is opened, and the filtration zone is connected to the collection cylinder. The fluid flowing out of the backflow zone is used to backwash the filtration zone, flushing the blockage inside the filtration zone into the collection cylinder. The cylindrical filter element is cleaned during the conveying process, and the fluid conveying does not need to be stopped when the collection cylinder is replaced, which improves the conveying efficiency and conveying stability.

[0026] 2. A flexible conduit is used to achieve a seal between the valve stem and the connecting seat. The flexible conduit is sleeved on the outside of the valve stem, with its upper end sealed to the bushing and its lower end sealed to the outer wall of the valve stem. When the valve stem moves up and down, the expansion and contraction of the flexible conduit can match the movement of the valve stem. Moreover, both ends of the flexible conduit are fixed connections, which provides a better sealing effect and a longer service life compared to sliding connections. Attached Figure Description

[0027] Figure 1 This is a schematic diagram illustrating the fluid filtration structure, which is the main feature of this application.

[0028] Figure 2 This is a schematic diagram of the interior of the shell in this application;

[0029] Figure 3 This is a schematic diagram of the internal structure of the cylindrical filter element in this application;

[0030] Figure 4 This is a cross-sectional structural schematic diagram of the pressure sensing mechanism in this application;

[0031] Figure 5 This is a cross-sectional view of the collection tube in this application;

[0032] Figure 6 This is a schematic diagram illustrating the main structure of the shut-off valve in this application;

[0033] Figure 7 This is a schematic diagram of the structure of the bushing and valve stem in this application;

[0034] Figure 8 This is a schematic diagram of the connection structure between the fluid filtration structure and the shut-off valve in this application.

[0035] Reference numerals: 1. Shell; 11. Inlet; 12. Outlet; 2. Cylindrical filter element; 21. Backflow zone; 22. Filtration zone; 3. Pressure sensing mechanism; 31. Fixed sleeve; 32. Moving piston; 33. Long groove; 34. Boss; 35. Concave hole; 36. Top pressure spring; 37. Top rod; 4. Moving cover; 41. First through hole; 5. Fixed plate; 51. Second through hole; 6. Transmission mechanism; 61. Connecting rod; 62. Ring; 63. Straight rod; 64. Retaining ring; 7. Drain pipe; 8. Automatic connection mechanism; 81. Connecting block; 82. Moving plate; 83. Connecting hole; 84. Bent rod; 9. Collection mechanism; 91. 92. Collection cylinder; 93. One-way inlet valve; 94. Sealing piston; 95. Vertical rod; 96. Tension spring; 97. Outer plate; 98. Slide rod; 99. Push plate; 10. Triangular extrusion plate; 10. One-way filling valve; 100. Valve seat; 101. Inlet channel; 102. Outlet channel; 103. Connecting channel; 200. Connecting seat; 201. Bushing; 202. Valve stem; 203. Sealing packing; 204. Pressing sleeve; 205. Elastic pipe; 206. Valve disc; 207. Flat groove; 208. Flange; 300. Top cover; 301. Extension screw; 302. Adjusting screw; 303. Handwheel; 400. Connecting piece. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1-8 This application will be described in further detail.

[0037] This application discloses a fluid filtration structure and a shut-off valve having the filtration structure.

[0038] Reference Figures 1 to 3 A fluid filtration structure includes a housing 1, with an inlet 11 and an outlet 12 connected to both ends of the housing 1. Inside the housing 1, a cylindrical filter element 2 with an end seal is fixedly installed on the side near the inlet 11. The cylindrical filter element 2 is provided with a filtration zone 22 and a backflow zone 21. A pressure sensing mechanism 3 is also provided at its sealed end to sense the pressure difference inside and outside the cylindrical filter element 2.

[0039] Inside the cylindrical filter element 2, a movable cover 4 with one open end is slidably disposed. The movable cover 4 is located inside the backflow zone 21. The bottom of the movable cover 4 has several first through holes 41. At the same time, a fixing plate 5 is fixed inside the cylindrical filter element 2. The fixing plate 5 has several second through holes 51. The positions of these second through holes 51 are staggered from the positions of the first through holes 41, and a sealing gasket is provided around the second through holes 51. When the movable cover 4 is in contact with the fixing plate 5, a seal can be achieved. The fixing plate 5 is located between the pressure sensing mechanism 3 and the movable cover 4. Furthermore, a transmission mechanism 6 is provided between the movable cover 4 and the pressure sensing mechanism 3, the function of which is to move the movable cover 4.

[0040] A drain pipe 7 is fixed to the outside of the filter zone 22. An automatic connection mechanism 8 is installed on the drain pipe 7. The end of the drain pipe 7 away from the cylindrical filter element 2 passes through the housing 1 and is connected to the collection mechanism 9. The collection mechanism 9 includes a replaceable collection cylinder 91, which is connected to the drain pipe 7 by a thread and can be replaced.

[0041] Fluid flows into housing 1 through inlet 11. After entering housing 1, the fluid passes through the first through hole 41 at the bottom of movable cover 4 and the second through hole 51 on fixed plate 5, and then enters cylindrical filter element 2. Under the action of filtration zone 22 of cylindrical filter element 2, impurities in the fluid are intercepted, achieving filtration. The filtered clean fluid flows out from cylindrical filter element 2 and is finally discharged from outlet 12.

[0042] As the filtration process continues, if the filtration zone 22 of the cylindrical filter element 2 gradually becomes clogged with impurities, the pressure balance inside and outside the cylindrical filter element 2 will be disrupted, creating a pressure difference. When this pressure difference reaches a preset standard, the pressure sensing mechanism 3 installed at the sealed end of the cylindrical filter element 2 will immediately respond. The pressure sensing mechanism 3 drives the movable cover 4 to slide towards the fixed plate 5 via the transmission mechanism 6 until the movable cover 4 is tightly fitted onto the fixed plate 5. At this time, the first through hole 41 and the second through hole 51 are offset from each other and form a sealed state, blocking the original normal filtration path of the fluid.

[0043] Simultaneously, the pressure sensing mechanism 3 also drives the automatic connection mechanism 8 to open the drain pipe 7. At this time, the flow direction of the fluid changes. Part of the fluid flows from the backflow zone 21 to the outside of the cylindrical filter element 2 and is discharged from the outlet 12; the other part of the fluid flows back from the outside of the filter zone 22 to the inside, backwashing the filter zone 22. During the backwashing process, the blockages attached to the filter zone 22 are washed off, and these blockages flow with the fluid into the collection cylinder 91 of the collection mechanism 9 through the open drain pipe 7.

[0044] After the collection cylinder 91 has collected the blockage, the pressure sensing mechanism 3 returns to its initial state, causing the moving cover 4 and the automatic connection mechanism 8 to reset as well. At this point, the fluid can smoothly pass through the first through hole 41 and the second through hole 51, just as it did initially, and then flow out from the filtration zone 22 to continue normal filtration. The intercepted blockage remains in the collection cylinder 91. Operators only need to replace the collection cylinder 91 periodically, without stopping the entire fluid transport process, to clean the cylindrical filter element 2, effectively preventing filter element blockage, significantly improving fluid transport efficiency, and fully meeting the needs of actual production.

[0045] refer to Figure 4The pressure sensing mechanism 3 is used to sense the pressure difference between the inside and outside of the cylindrical filter element 2. It is installed at the sealed end of the cylindrical filter element 2. The mechanism mainly consists of a fixing sleeve 31, which is fixed to the sealed end of the cylindrical filter element 2 by screws, and both ends of the fixing sleeve 31 are open.

[0046] A slidable movable piston 32 is provided on the inner side of the fixed sleeve 31. A long groove 33 is opened on the inner wall of the fixed sleeve 31, and a boss 34 is provided at the bottom of the long groove 33.

[0047] A recessed hole 35 is formed on the side wall of the movable piston 32, and a sliding push rod 37 is installed in the recessed hole 35. A pressure spring 36 is placed inside the recessed hole 35, with one end of the pressure spring 36 abutting against the bottom of the recessed hole 35 and the other end abutting against the push rod 37. The outer end of the push rod 37 is located in the elongated groove 33, and a ball is rotatably mounted on the push rod 37, with the ball abutting against the bottom of the elongated groove 33. When the pressure changes, the movable piston 32 has a tendency to slide outward.

[0048] When the filter zone 22 becomes clogged, the pressure inside the cylindrical filter element 2 gradually increases, eventually exceeding the pressure inside the housing 1. Under this pressure difference, the moving piston 32 experiences an outward thrust and begins to move outward.

[0049] At this time, the push rod 37, located in the recess 35 on the side wall of the moving piston 32, is pressed tightly against the bottom of the long groove 33 on the inner wall of the fixed sleeve 31 under the action of the top pressure spring 36. The boss 34 provided at the bottom of the long groove 33 will block the movement of the push rod 37, so that the moving piston 32 cannot move outward temporarily.

[0050] As the clogging of the filter zone 22 worsens, the pressure difference between the inside and outside of the cylindrical filter element 2 continues to increase. When the pressure difference reaches a preset standard, the pressure acting on the moving piston 32 overcomes the elastic force of the top spring 36. The top spring 36 is thus compressed, and the push rod 37 will pass over the obstruction of the boss 34. Once the push rod 37 passes over the boss 34, the moving piston 32 is no longer obstructed and will move directly to the outermost position of the fixed sleeve 31 under the pressure.

[0051] refer to Figure 3 The transmission mechanism 6 includes a straight rod 63 fixed to the end of the movable piston 32. Two retaining rings 64 are fixed on the straight rod 63. Several connecting rods 61 are fixed on the movable cover 4. The connecting rods 61 pass through the second through hole 51 at the corresponding position. A ring 62 is fixed to the end of the connecting rod 61 away from the movable cover 4. The straight rod 63 passes through the middle of the ring 62. The two retaining rings 64 are located on both sides of the two rings 62 respectively. The outer diameter of the retaining rings 64 is larger than the inner diameter of the rings 62.

[0052] When the moving piston 32 moves outward due to the pressure difference between the inside and outside of the cylindrical filter element 2, the straight rod 63 connected to it also moves outward synchronously. Two retaining rings 64 are fixed on the straight rod 63, and these two retaining rings 64 will pull the ring 62 sleeved on the straight rod 63 to move together.

[0053] The ring 62 is fixedly connected to the movable cover 4 by several connecting rods 61. Therefore, when the ring 62 moves with the straight rod 63, it will drive the movable cover 4 to move towards the fixed plate 5 with the help of the connecting rods 61. Finally, the movable cover 4 will fit tightly against the fixed plate 5.

[0054] As the movable cover 4 and the fixed plate 5 come into contact, the first through hole 41 at the bottom of the movable cover 4 and the second through hole 51 on the fixed plate 5 will be offset from each other and sealed, blocking the original flow path of the fluid. At the same time, the backflow zone 21 is opened, allowing the fluid to change its flow direction and achieve subsequent backwashing and other functions.

[0055] refer to Figure 3 and Figure 4 The automatic connection mechanism 8 is used to control the opening and closing of the sewage pipe 7, and it mainly consists of the following parts. Two connecting blocks 81 are fixedly installed on both sides of the sewage pipe 7. A sliding groove is opened in the middle of the sewage pipe 7, which divides the sewage pipe 7 into upper and lower parts, and these two parts are firmly connected together by the connecting blocks 81 on both sides.

[0056] A sliding movable plate 82 is installed inside the chute. A connecting hole 83 is opened at one end of the movable plate 82 near the movable cover 4. When the connecting hole 83 is aligned with the upper and lower parts of the drain pipe 7, the drain pipe 7 will be connected. A bent rod 84 is fixedly connected to the other end of the movable plate 82, and the other end of the bent rod 84 is connected to the end of the movable piston 32.

[0057] When the moving piston 32 moves under the action of pressure difference, it will drive the moving plate 82 to slide in the groove through the bent rod 84, thereby connecting or separating the connecting hole 83 from the upper and lower parts of the drain pipe 7, so as to realize the opening or closing of the drain pipe 7.

[0058] The movable plate 82 is inserted into the drain pipe 7 to isolate the drain pipe 7 and prevent fluid from flowing through the drain pipe 7. When the movable piston 32 moves outward under the action of pressure difference, the bent rod 84 will drive the movable plate 82 to move, and make the connecting hole 83 move to align with the drain pipe 7. At this time, the drain pipe 7 can be opened, and the blockage can flow through the drain pipe 7 into the collection cylinder 91.

[0059] refer to Figure 1 and Figure 5The collection mechanism 9 includes a replaceable collection cylinder 91 and several other key components. Inside the collection cylinder 91, there is a sliding sealing piston 93. The upper end of the collection cylinder 91 has a notch through which it is threadedly connected to the drain pipe 7, ensuring a secure connection and facilitating subsequent disassembly and replacement. Inside the notch, a one-way inlet valve 92 is installed, ensuring that fluid can only flow into the collection cylinder 91 from the drain pipe 7 in one direction.

[0060] A slidable vertical rod 94 is provided in the middle of the sealing piston 93. A circular plate is fixed to the upper end of the vertical rod 94, and a tension spring 95 connects the circular plate and the sealing piston 93. The bottom of the collecting cylinder 91 has a sliding hole and several vent holes. The bottom of the vertical rod 94 is inserted into the sliding hole, and several outward-spreading plates 96 are provided at the bottom of the vertical rod 94. The lower ends of these outward-spreading plates 96 abut against the inner wall of the collecting cylinder 91, so that the vertical rod 94 can maintain a stable position at the bottom of the collecting cylinder 91.

[0061] Two symmetrically distributed slide rods 97 are slidably inserted into the housing 1, and a reinforcing sleeve is provided on the outer side of the housing 1 to prevent the two slide rods 97 from tilting. The two slide rods 97 are connected together at one end inside the housing 1 by a crossbar, and at the other end outside the housing 1 by a push plate 98. In addition, a triangular compression plate 99 is fixed on the bent rod 84, and the crossbar is located directly above the triangular compression plate 99. When the bent rod 84 moves with the moving piston 32, the triangular compression plate 99 pushes the crossbar, thereby driving the slide rods 97 and the push plate 98 to move.

[0062] When the filter zone 22 becomes clogged, creating a pressure difference between the inside and outside of the cylindrical filter element 2, the moving piston 32 moves outward under the action of this pressure difference. At this time, the bent rod 84 connected to the moving piston 32 moves accordingly, thereby driving the triangular compression plate 99 fixed on the bent rod 84 to move synchronously. The triangular compression plate 99 has an inclined surface, and when it moves below the crossbar, it will push the crossbar upward with the inclined surface. The crossbar is also connected to two symmetrical sliding rods 97 located inside the housing 1, so the upward movement of the crossbar drives the sliding rods 97 to move upward together, ultimately lifting the push plate 98 located outside the housing 1.

[0063] The collecting cylinder 91 is threadedly connected to the drain pipe 7 via a notch at its upper end. When the automatic connecting mechanism 8 is triggered, the fluid carrying the blockage flows into the collecting cylinder 91 through the drain pipe 7 and smoothly passes through the one-way inlet valve 92 inside the notch. As the inflowing fluid increases, the pressure inside the collecting cylinder 91 gradually rises, pushing the sealing piston 93 towards the bottom of the collecting cylinder 91. However, the outwardly extending plate 96 at the bottom of the vertical rod 94 abuts against the inner wall of the collecting cylinder 91, preventing the vertical rod 94 from moving downward with the sealing piston 93, causing the tension spring 95 connecting the circular plate and the sealing piston 93 to be gradually stretched.

[0064] As the sealing piston 93 continues to move downwards to the position of the outward-spreading plate 96, the sealing piston 93 compresses the outward-spreading plate 96, causing it to contract inwards. After the outward-spreading plate 96 contracts, the vertical rod 94 is no longer obstructed and quickly moves downwards under the tension of the tension spring 95. The downward-moving vertical rod 94 strikes the previously raised push plate 98, causing the push plate 98 and the connected slide rod 97 to move downwards. The slide rod 97 transmits force through the crossbar, pushing the triangular compression plate 99 downwards, thereby restoring the bent rod 84 to its initial position. At the same time as the bent rod 84 resets, it also drives the connected moving piston 32 to reset. The moving piston 32 then pulls the straight rod 63 through the connecting rod 61, thereby driving the moving cover 4 to reset. At this point, the entire system achieves full-range automatic reset, preparing for the next cycle of cleaning function activation.

[0065] A one-way filling valve 10 is connected to the drain pipe 7, and the one-way filling valve 10 is located on the outside of the housing 1.

[0066] When transporting hazardous fluids such as liquefied natural gas, before replacing the collection cylinder 91, a filling device can be used to fill the drain pipe 7 with safe filling fluid through the one-way filling valve 10, so that the residual hazardous fluid is fully squeezed into the collection cylinder 91, and then the collection cylinder 91 can be removed, making the operation safer.

[0067] The implementation principle of the fluid filtration structure in this application is as follows: when the filtration zone 22 is blocked, filtration is carried out through the backflow zone 21, and the filtered fluid is used to backwash the filtration zone 22, collecting the blockage in the collection cylinder 91 for easy replacement. The cylindrical filter element 2 can be cleaned without stopping the conveying, achieving the anti-clogging effect, improving the conveying efficiency, and benefiting actual production needs.

[0068] refer to Figure 6 and Figure 7 A shut-off valve is described, comprising core components such as a valve seat 100, a connecting seat 200, and a top cover 300. The valve seat 100 has an inlet channel 101 and an outlet channel 102 on both sides, which are interconnected by a connecting channel 103. The aforementioned fluid filtration structure is mounted on the valve seat 100, and the inlet channel 101 is connected to the outlet port 12. The connecting seat 200 is bolted to the upper end of the valve seat 100, and a bushing 201 is provided on its inner upper end. The valve stem 202 is slidably inserted between the bushing 201 and the connecting seat 200, and an elastic conduit 205 (which can be a metal bellows or similar structure) is fitted on its outer side. The upper end of the elastic conduit 205 is sealed to the bushing 201, and the lower end is tightly sealed to the outer wall of the valve stem 202 to ensure no fluid leakage. The lower end of the valve stem 202 is connected to a valve disc 206 for controlling the flow of fluid.

[0069] The top cover 300 is positioned above the connecting seat 200 and is securely connected to the connecting seat 200 via an extension screw 301. An adjusting screw 302 is threadedly fitted into the middle of the top cover 300, and a handwheel 303 is fixed to the upper end of the adjusting screw 302 for easy manual adjustment. The adjusting screw 302 and the valve stem 202 are connected via a connector 400, enabling them to work together.

[0070] A packing cavity is provided inside the bushing 201, which is filled with sealing packing 203 to enhance the sealing performance. A pressure sleeve 204 is installed at the upper end of the sealing packing 203. The pressure sleeve 204 is connected to the outside of the connecting seat 200 by bolts on both sides, which can apply pressure to the sealing packing 203 to ensure the sealing effect.

[0071] The valve stem 202 has a flat groove 207 on its outer side, and the inner bottom of the bushing 201 has a matching flange 208. This structural design ensures that the valve stem 202 can slide smoothly while preventing it from rotating. The connecting piece 400 consists of two clamping pieces, which are fastened together by bolts. The bottom of the adjusting screw 302 and the top of the valve stem 202 are both provided with connecting heads. These two connecting heads are located between the two clamping pieces and can rotate relative to each other. This allows the valve stem 202 to respond accurately when the adjusting screw 302 is raised or lowered, but the valve stem 202 will not rotate when the adjusting screw 302 rotates.

[0072] When the operator rotates the handwheel 303, the handwheel 303 drives the adjusting screw 302, which is fixedly connected to it, to move up and down. Since the adjusting screw 302 is connected to the valve stem 202 through the connector 400, the valve stem 202 will move up and down synchronously with the adjusting screw 302 under the action of the connector 400.

[0073] When the valve stem 202 rises, the valve disc 206 connected to it also rises, thus separating the valve disc 206 from the connecting channel 103. At this time, the shut-off valve opens, and fluid can flow through the inlet channel 101, the connecting channel 103, and the outlet channel 102. Conversely, when the valve stem 202 descends, the valve disc 206 also descends until it comes into close contact with the edge of the connecting channel 103, at which point the shut-off valve closes, blocking the flow of fluid.

[0074] During the up-and-down movement of the valve stem 202, the elastic conduit 205, fitted around the outside of the valve stem 202, can flexibly cooperate with the lifting and lowering movements of the valve stem 202. Moreover, the upper end of the elastic conduit 205 is sealed to the bushing 201, and the lower end is sealed to the outer wall of the valve stem 202. This ensures that the elastic conduit 205 maintains a good sealing state throughout the movement of the valve stem 202, effectively preventing fluid leakage.

[0075] The inner packing cavity of the bushing 201 is filled with sealing packing 203. The pressure sleeve 204 is installed on the upper end of the sealing packing 203 and connected to the outer side of the connecting seat 200 by bolts on both sides. The pressure sleeve 204 can tightly press the sealing packing 203 into the packing cavity, which further enhances the sealing effect without hindering the normal rise and fall of the valve stem 202. Together with the sealing effect of the elastic pipe 205, it achieves a secondary seal.

[0076] A flat groove 207 is provided on the outer side of the valve stem 202, and a flange 208 provided on the bottom inner side of the bushing 201 matches the flat groove 207. This structural design prevents the valve stem 202 from rotating during vertical movement. The adjusting screw 302 and the valve stem 202 are connected by a connector 400 consisting of two clamps. This connection method can effectively transmit the power of the adjusting screw 302's vertical movement to the valve stem 202, realizing power transmission during the lifting and lowering process. However, since the two connectors can rotate relative to each other between the clamps, when the adjusting screw 302 rotates during the lifting and lowering process, the valve stem 202 will only move up and down and will not rotate with the adjusting screw 302. This feature effectively prevents the elastic pipe 205 from twisting due to the rotation of the valve stem 202, thereby extending the service life of the elastic pipe 205.

[0077] The implementation principle of the gate valve in this application is as follows: the elastic pipe 205 is used to match the up and down movement of the valve stem 202. Both ends of the elastic pipe 205 are fixedly connected, resulting in a good sealing effect. Moreover, the pressure sleeve 204 can tightly press the sealing packing 203 into the packing cavity. While not hindering the normal lifting and lowering of the valve stem 202, it further enhances the sealing effect. Together with the sealing effect of the elastic pipe 205, it achieves a secondary seal. In addition, the adjusting screw 302 and the valve stem 202 only perform lifting and lowering transmission, not rotational transmission, which effectively avoids the elastic pipe 205 from twisting due to the rotation of the valve stem 202, thereby extending the service life of the elastic pipe 205.

[0078] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A fluid filtration structure, characterized in that: The system includes a housing (1), with an inlet (11) and an outlet (12) connected to its two ends respectively. A cylindrical filter element (2) with an end seal is fixed inside the housing (1) near the inlet (11). The cylindrical filter element (2) has a filtration zone (22) and a backflow zone (21). A pressure sensing mechanism (3) for sensing internal and external pressure is provided at the sealed end of the cylindrical filter element (2). A movable cover (4) with an open end is slidably disposed inside the cylindrical filter element (2). The movable cover (4) is located inside the backflow zone (21), and several first through holes (41) are opened at the bottom of the movable cover (4). A fixed... The plate (5) is provided with several second through holes (51) that are diverged from the first through hole (41). The fixed plate (5) is located between the pressure sensing mechanism (3) and the moving cover (4). A transmission mechanism (6) for moving the moving cover (4) is provided between the moving cover (4) and the pressure sensing mechanism (3). A drain pipe (7) is fixed on the outside of the filter area (22). An automatic connection mechanism (8) is provided on the drain pipe (7). The end of the drain pipe (7) away from the cylindrical filter element (2) passes through the housing (1) and is connected to a collection mechanism (9). The collection mechanism (9) includes a replaceable collection cylinder (91). The collection cylinder (91) is threadedly connected to the drain pipe (7).

2. The fluid filtration structure according to claim 1, characterized in that: The pressure sensing mechanism (3) includes a fixed sleeve (31) fixed to the sealing end of the cylindrical filter element (2), and the fixed sleeve (31) has openings at both ends. A movable piston (32) is slidably arranged on the inner side of the fixed sleeve (31). A long groove (33) is opened on the inner wall of the fixed sleeve (31), and a boss (34) is provided at the bottom of the long groove (33). A concave hole (35) is opened on the side wall of the movable piston (32). A push rod (37) is slidably arranged in the concave hole (35). A top pressure spring (36) is arranged inside the concave hole (35). The two ends of the top pressure spring (36) abut against the bottom of the concave hole (35) and the push rod (37) respectively, and the outer end of the push rod (37) is located in the long groove (33).

3. The fluid filtration structure according to claim 2, characterized in that: The transmission mechanism (6) includes a straight rod (63) fixed to the end of the movable piston (32). Two retaining rings (64) are fixed on the straight rod (63). Several connecting rods (61) are fixed on the movable cover (4). The connecting rods (61) pass through the second through hole (51) at the corresponding position. A ring (62) is fixed at the end of the connecting rod (61) away from the movable cover (4). The straight rod (63) passes through the middle of the ring (62). The two retaining rings (64) are located on both sides of the two rings (62). The outer diameter of the retaining ring (64) is larger than the inner diameter of the ring (62).

4. The fluid filtration structure according to claim 3, characterized in that: The automatic connection mechanism (8) includes two connecting blocks (81) fixed on both sides of the sewage pipe (7), and a slid groove is provided in the middle of the sewage pipe (7). The slid groove divides the sewage pipe (7) into upper and lower parts, and the upper and lower parts of the sewage pipe (7) are fixedly connected by the connecting blocks (81). A movable plate (82) is slidably arranged in the slid groove. A connecting hole (83) is provided at one end of the movable plate (82) near the movable cover (4). A bent rod (84) is fixed at the other end of the movable plate (82), and the other end of the bent rod (84) is connected to the end of the movable piston (32).

5. A fluid filtration structure according to claim 4, characterized in that: The collection mechanism (9) further includes a sealing piston (93) slidably disposed inside the collection cylinder (91). The upper end of the collection cylinder (91) is provided with a notch, and the collection cylinder (91) is threadedly connected to the drain pipe (7) through the notch. A one-way inlet valve (92) is connected to the inner side of the notch. A vertical rod (94) is slidably disposed in the middle position of the sealing piston (93), and a circular plate is fixed at the upper end of the vertical rod (94). A tension spring (95) is connected between the circular plate and the sealing piston (93). The bottom of the collection cylinder (91) is provided with a sliding hole and several vent holes. The vertical rod (94) is slidably disposed in the middle position of the sealing piston (93). 4) The bottom of the vertical rod (94) is inserted into the sliding hole, and the bottom of the vertical rod (94) is provided with several outwardly extending pieces (96), and the lower end of the outwardly extending pieces (96) abuts against the inner wall of the collecting cylinder (91). Two symmetrically distributed sliding rods (97) are slidably inserted on the shell (1). The two sliding rods (97) are connected to each other by a crossbar at one end inside the shell (1), and the two sliding rods (97) are connected to each other by a push plate (98) at one end outside the shell (1). A triangular extrusion plate (99) is fixed on the bent rod (84), and the crossbar is located directly above the triangular extrusion plate (99).

6. The fluid filtration structure according to claim 1, characterized in that: The drain pipe (7) is connected to a one-way filling valve (10), and the one-way filling valve (10) is located on the outside of the housing (1).

7. A shut-off valve, characterized in that: A fluid filtration structure according to any one of claims 1-6, comprising a valve seat (100), a connecting seat (200), and a top cover (300), wherein an inlet channel (101) and an outlet channel (102) are respectively provided on both sides of the valve seat (100), and a connecting channel (103) is provided between the inlet channel (101) and the outlet channel (102), the connecting seat (200) is bolted to the upper end of the valve seat (100), a bushing (201) is provided on the upper inner side of the connecting seat (200), and a valve stem (202) is slidably inserted between the bushing (201) and the connecting seat (200). An elastic pipe (205) is sleeved on the outside of the valve stem (202). The upper end of the elastic pipe (205) is sealed to the bushing (201), and the lower end is sealed to the outer wall of the valve stem (202). A valve disc (206) is connected to the lower end of the valve stem (202). The top cover (300) is located above the connecting seat (200), and the top cover (300) and the connecting seat (200) are connected by an extension screw (301). An adjusting screw (302) is threaded in the middle of the top cover (300), and a handwheel (303) is fixed at the upper end of the adjusting screw (302). The adjusting screw (302) and the valve stem (202) are connected by a connector (400).

8. A shut-off valve according to claim 7, characterized in that: The inner side of the bushing (201) is provided with a packing cavity, and the packing cavity is filled with sealing packing (203). The upper end of the sealing packing (203) is provided with a pressure sleeve (204), and the two sides of the pressure sleeve (204) are connected to the outside of the connecting seat (200) by bolts.

9. A shut-off valve according to claim 7, characterized in that: The valve stem (202) has a flat groove (207) on its outer side, and the inner bottom of the bushing (201) has a flange (208) that matches the flat groove (207). The connector (400) includes two clamps that are connected by bolts. The bottom of the adjusting screw (302) and the top of the valve stem (202) are both provided with connectors. The two connectors are located between the two clamps and can rotate relative to each other.

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