Maintenance-free automatic exhaust valve

Abstract

The utility model discloses a maintenance-free automatic exhaust valve which comprises a valve body, the bottom of the valve body is fixedly communicated with an inlet pipe, the top of the valve body is fixedly communicated with a vertical pipe, the top end of the vertical pipe is of a plugging structure, and the top of the right side of the vertical pipe is fixedly communicated with an exhaust pipe. According to the utility model, a series of structures are arranged, so that when the water level rises and enters, the ventilation and exhaust work can be carried out by utilizing buoyancy to automatically close air and utilizing water level to lower to automatically unseal, and the effects of automatic and safe exhaust and application are realized; the phenomenon that water enters the inner side of the blocking and closing position to generate scaling and affect use can be avoided, the beneficial application effect on the maintenance-free aspect is achieved, the two filter screens can be automatically and alternately utilized and alternately back-blown, cleaned and dredged at regular time, long-acting use smoothness of the filter screens is guaranteed, workers do not need to disassemble, assemble, clean and dredge, and the working efficiency is improved. And the maintenance-free long-term smooth application effect is good, and the maintenance frequency and work are reduced.

Description

Technical Field

[0001] This utility model relates to the field of exhaust technology for heating systems, specifically to a maintenance-free automatic exhaust valve. Background Technology

[0002] In the application of air venting in heating systems, the valve needle of ordinary air vents is prone to blockage due to scale buildup in the water, preventing automatic air venting and requiring manual venting, which greatly increases the workload of employees. Furthermore, the inability to promptly expel gas from the heating system leads to blockages, resulting in poor circulation of the heating water and affecting heating quality, causing significant user complaints. Additionally, the filter screen inside the air vent, used to filter solids during water intake, can also become clogged, requiring periodic manual removal and cleaning, making it inconvenient to use. Therefore, this application proposes a maintenance-free automatic air vent to solve the aforementioned problems. Utility Model Content

[0003] The purpose of this invention is to provide a maintenance-free automatic exhaust valve to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a maintenance-free automatic air venting valve, comprising a valve body, an inlet pipe fixedly connected to the bottom of the valve body, a vertical pipe with a sealing structure at the top of the valve body, and an exhaust pipe fixedly connected to the top right side of the vertical pipe. The same floating self-closing venting component is installed inside the valve body and the vertical pipe. The inlet pipe is connected to the upper part of the heating system carrier. Heating system gas is discharged into the valve body through the inlet pipe, and the gas is discharged sequentially through the vertical pipe and the exhaust pipe. The floating self-closing venting component automatically seals the inside of the vertical pipe by using buoyancy when the water level of the heating system rises and enters the valve body after the gas is discharged, thus automatically ending the venting and preventing water from being discharged through the exhaust pipe. It also automatically unseals the inside of the vertical pipe to vent when the water level drops due to water loss in the heating system, preventing negative pressure from affecting the safety of the heating system facilities.

[0005] Rectangular boxes are embedded and fixed on both sides of the valve body. The adjacent sides of the two rectangular boxes are both open. A common transverse sliding plate is sealed and slidably fitted inside both rectangular boxes. Two filter screens are embedded and fixed on the top of the transverse sliding plate. The top of the filter screen on the right side is in movable contact with the bottom of the floating self-closing venting component. The bottom of the rectangular box has a slag discharge hole that matches the corresponding filter screen. A multi-stage electric telescopic rod with its extended end fixedly connected to the bottom left side of the rectangular box on the left side is fixedly connected to the bottom left side of the transverse sliding plate. A timer controller is fixedly installed on the top left side of the valve body. A common timer for controlling the two rectangular boxes is embedded on the top of the two rectangular boxes. The alternating backflushing cleaning component, which alternately backflushes and cleans the filters, is electrically connected to a timer controller along with a multi-stage electric telescopic rod. The filters are used to intercept solids in the water as it enters, preventing them from condensing and causing blockages in the ventilation area of ​​the vertical pipe. The multi-stage electric telescopic rod, controlled by the timer controller, drives a horizontal plate to move cyclically left and right, alternating between the two filters. The alternating backflushing cleaning component, also controlled by the timer controller, switches air supply to both sides at regular intervals to alternately clean and unclog the two filters.

[0006] Preferably, the floating self-closing venting assembly includes a conical rubber sleeve bonded inside a vertical pipe, a hollow float inside the valve body, a valve needle with a conical top fixedly connected to the top of the hollow float, the valve needle being adapted to the inner side of the conical rubber sleeve, counterweight guide rods fixedly connected to both sides of the top of the hollow float, two positioning tubes respectively sealed and slidably sleeved on the corresponding counterweight guide rods being embedded and fixed at the top of the valve body, the top of the positioning tubes being configured as a sealing structure, and the bottom of the hollow float being in movable contact with the top of the filter screen on the right side.

[0007] Preferably, the alternating backflush cleaning assembly includes a U-shaped tube fixedly sleeved on the outside of the valve body, an air pump fixedly installed on the left side of the valve body with its air outlet connected to the top of the U-shaped tube, air distribution boxes embedded and fixedly installed on the top of the two rectangular boxes, multiple backflush pipe heads connected and fixedly installed at the bottom of the air distribution boxes, solenoid valves connected and fixedly installed on both sides of the U-shaped tube, and the same L-shaped tube connected and fixedly installed between the end of the solenoid valve away from the U-shaped tube and the top of the corresponding air distribution box, and the solenoid valve and the air pump are electrically connected to the timer controller.

[0008] Preferably, the inner diameter of the exhaust pipe is smaller than the inner diameter of the vertical pipe, and the inner diameter of the vertical pipe is smaller than the inner diameter of the inlet pipe.

[0009] Preferably, the top of the valve body has two vertical guide holes, and a first thin sealing sleeve is adhesively fitted inside the vertical guide holes to slide and fit against the outer side of the corresponding counterweight guide rod.

[0010] Preferably, the inner side of the rectangular box is provided with a second thin sealing sleeve that slides in contact with the outer side of the transverse plate. The top and bottom of the second thin sealing sleeve are provided with connecting holes, and the gas distribution box and the slag discharge hole are vertically aligned with the corresponding connecting holes.

[0011] Preferably, the front and rear sides of the transverse plate are in sliding contact with the front and rear inner walls of the valve body, respectively.

[0012] Compared with the prior art, the beneficial effects of this utility model are:

[0013] 1. Through the coordinated design of the valve body, inlet pipe, vertical pipe, exhaust pipe, and floating self-closing venting component, the system can automatically close the vent when the water level rises and automatically open the vent when the water level drops, allowing for continued venting. This effectively prevents negative pressure from forming in the heating system when the water level drops, thus ensuring the safety of the facilities. It achieves automated and safe venting and application. Combined with the filter screen to filter solids, it reduces the amount of solids entering the upper part and causing scaling. Furthermore, with the valve needle top higher than the bottom of the vertical pipe, water will not enter the sealed area inside the vertical pipe or the exhaust pipe. Compared to traditional ordinary exhaust valves, it effectively prevents scaling inside the conical rubber sleeve of the exhaust pipe, avoiding the need for manual operation and handling due to scaling at the venting and sealing points. In comparison, it has the beneficial effect of maintenance-free application, greatly reducing the workload of employees and improving user satisfaction.

[0014] 2. By using the alternating backflushing cleaning components, filter screen, rectangular box, transverse plate, multi-stage electric telescopic rod and timer controller, the two filter screens can be automatically and alternately used and backflushed for cleaning and unblocking at regular intervals, ensuring their long-term smooth operation. Through automatic alternating use and unblocking, no personnel are required to disassemble, clean and unblock, which has a good maintenance-free long-term smooth application effect, reducing maintenance frequency and workload.

[0015] This utility model, through a series of structures, can automatically seal the air when the water level rises and automatically unseal it when the water level drops, achieving automated and safe venting and application. Furthermore, by filtering and sealing solids above the bottom of the vertical pipe, it prevents water from entering the sealed area and causing scale buildup, thus avoiding problems with usability. This provides a maintenance-free application effect. It also facilitates the automatic, alternating use and backflushing of the two filters to ensure long-term unobstructed operation, eliminating the need for manual disassembly, cleaning, and unblocking. This results in a good maintenance-free, long-term unobstructed application effect, reducing maintenance frequency and workload. Attached Figure Description

[0016] Figure 1This is a schematic diagram of the structure of a maintenance-free automatic exhaust valve proposed in this utility model;

[0017] Figure 2 for Figure 1 A diagram of the internal structure viewed from below;

[0018] Figure 3 This is a schematic diagram of the main cross-sectional structure of a maintenance-free automatic exhaust valve proposed in this utility model;

[0019] Figure 4 for Figure 3 A magnified structural diagram of part A in the diagram.

[0020] In the diagram: 1. Valve body; 101. Inlet pipe; 102. Vertical pipe; 103. Exhaust pipe; 104. Rubber sleeve; 105. Valve needle; 106. Counterweight guide rod; 107. Hollow float; 2. Rectangular box; 201. Slag discharge hole; 202. Horizontal sliding plate; 203. Filter screen; 204. Multi-stage electric telescopic rod; 3. Air pump; 301. U-shaped pipe; 302. Solenoid valve; 303. L-shaped pipe; 304. Air distribution box; 4. Timer controller. Detailed Implementation

[0021] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0022] like Figures 1 to 4 As shown, this embodiment proposes a maintenance-free automatic exhaust valve, including a valve body 1. An inlet pipe 101 is fixedly connected to the bottom of the valve body 1, and a vertical pipe 102 with a sealed top is fixedly connected to the top of the valve body 1. An exhaust pipe 103 is fixedly connected to the top right side of the vertical pipe 102. The same floating self-closing venting assembly is installed inside the valve body 1 and the vertical pipe 102. The inner diameter of the exhaust pipe 103 is smaller than the inner diameter of the vertical pipe 102, and the inner diameter of the vertical pipe 102 is smaller than the inner diameter of the inlet pipe 101. The inlet pipe 101 is used to connect to a heating system. At the top of the system carrier, the heating system gas is discharged into the valve body 1 through the inlet pipe 101. The gas is discharged sequentially through the vertical pipe 102 and the exhaust pipe 103. The floating self-closing venting component is used to automatically seal the inside of the vertical pipe 102 by means of water buoyancy when the water level of the heating system rises and enters the valve body 1 after the gas is discharged, so as to automatically end the venting and prevent water from being discharged through the exhaust pipe. It is also used to automatically unseal the inside of the vertical pipe 102 for venting when the water level drops due to water loss in the heating system, so as to prevent negative pressure in the heating system from affecting the safety of the heating system facilities.

[0023] Rectangular boxes 2 are fixedly embedded on both sides of the valve body 1. The adjacent sides of the two rectangular boxes 2 are both open. A transverse sliding plate 202 is sealed and slidably fitted inside both rectangular boxes 2. The front and rear sides of the transverse sliding plate 202 slide in contact with the front and rear inner walls of the valve body 1, respectively. Two filter screens 203 are fixedly embedded in the top of the transverse sliding plate 202. The top of the filter screen 203 on the right side is in movable contact with the bottom of the floating self-closing air venting component. A slag discharge hole 201 corresponding to the filter screen 203 is opened at the bottom of the rectangular box 2. A multi-stage electric telescopic rod 204 with its extended end fixedly connected to the bottom left side of the transverse sliding plate 202 is fixedly connected to the left side of the bottom of the rectangular box 2 on the left side. The extended end of the multi-stage electric telescopic rod 204 communicates with the bottom left side of the transverse sliding plate 202 through a slag discharge hole 201 located on the left side. The valve body 1 has a connecting seat and a timer controller 4 fixedly installed on the top left side. The top of the two rectangular boxes 2 is fitted with the same alternating backflushing cleaning component for alternately backflushing and cleaning the two filter screens 203. The alternating backflushing cleaning component and the multi-stage electric telescopic rod 204 are electrically connected to the timer controller 4. The filter screens 203 are used to filter and intercept solids in the water when water enters, preventing solids from entering the ventilation position of the vertical pipe 102 and condensing to cause blockage. The multi-stage electric telescopic rod 204 is controlled by the timer controller 4 to drive the horizontal plate 202 to move cyclically right and left. The horizontal plate 202 drives the two filter screens 203 to move cyclically right and left for alternate use. The alternating backflushing cleaning component is controlled by the timer controller 4 to switch the air supply to both sides at timed intervals and to alternately clean and unclog the two filter screens 203.

[0024] Specifically, the floating self-closing venting assembly includes a conical rubber sleeve 104 bonded inside the vertical pipe 102, a hollow float 107 inside the valve body 1, a valve needle 105 with a conical top fixedly connected to the top of the hollow float 107, the valve needle 105 being adapted to the inner side of the conical rubber sleeve 104, and counterweight guide rods 106 fixedly connected to both sides of the top of the hollow float 107. Two positioning tubes 108 are embedded and fixedly mounted on the top of the valve body 1, respectively sealing and slidingly fitted onto the corresponding counterweight guide rods 106. The top of the positioning tubes 108 is configured as a sealing structure. The outer side of rod 106 is bonded with a first thin sealing sleeve. The outer side of the first thin sealing sleeve slides in contact with the inner wall of the corresponding positioning tube 108, which serves to vertically seal and guide the counterweight guide rod 106. The bottom of the hollow float 107 is in movable contact with the top of the filter screen 203 on the right side. The conical rubber sleeve 104, hollow float 107, valve needle 105, counterweight guide rod 106 and positioning tube 108 work together so that when the water level in the heating system rises and enters the valve body 1, the buoyancy of the liquid drives the hollow float 107 to move upward, and the hollow float 107 drives the valve needle 105 to move upward. The upper part is squeezed tightly against the inner side of the conical rubber sleeve 104 to perform a sealing and plugging operation, realizing the automatic end of the venting state and preventing water from entering the vertical pipe 102 and being discharged through the vent pipe 103. When the water level drops due to water loss in the heating system, the hollow float 107 and the counterweight guide rod 106 move downward under their own weight. The hollow float 107 drives the valve needle 105 downward to separate from the inner side of the conical rubber sleeve 104, realizing the effect of automatic unsealing and venting when the water level drops due to water loss. This prevents negative pressure in the heating system from affecting the safety of the heating system facilities. It automatically closes the vent when the water level rises and automatically closes the vent when the water level drops. With automatic unsealing for ventilation and subsequent continued venting, the system achieves automated and safe venting and application. Combined with the filter screen 203 for filtering solids, and the valve needle 105 being positioned so that its top is higher than the bottom of the vertical pipe 102, water will not enter the vertical pipe 102 or the vent pipe 103. Compared to traditional ordinary vent valves, this effectively prevents scaling in the vent pipe 103 and vertical pipe 102, avoiding malfunctions caused by scaling at the ventilation / sealing points that require manual operation and handling. Therefore, it offers the advantage of maintenance-free operation.

[0025] Furthermore, the alternating backflushing cleaning assembly includes a loop tube 301 fixedly sleeved on the outside of the valve body 1, an air pump 3 fixedly installed on the left side of the valve body 1 with its air outlet connected to the top of the loop tube 301, a gas distribution box 304 fixedly embedded in the top of each of the two rectangular boxes 2, multiple backflushing pipe heads fixedly connected to the bottom of the gas distribution box 304, a solenoid valve 302 fixedly connected to both sides of the loop tube 301, an L-shaped pipe 303 fixedly connected between the end of the solenoid valve 302 away from the loop tube 301 and the top of the corresponding gas distribution box 304, the solenoid valve 302 and the air pump 3 are electrically connected to the timer controller 4, a second thin sealing sleeve is adhesively sleeved on the inner side of the rectangular box 2 and slides in contact with the outer side of the transverse plate 202, the top and bottom of the second thin sealing sleeve are provided with connecting holes, and the gas distribution box 304 and the slag discharge hole 201 are vertically aligned with the corresponding connecting holes respectively;

[0026] The system consists of a U-shaped pipe 301, an air pump 3, an air distribution box 304, a backflush nozzle, a solenoid valve 302, and an L-shaped pipe 303. A timer controller 4 is used to preset and control the operation of the air pump 3, the forward and reverse directions of the multi-stage electric telescopic rod 204, and the opening and closing times and intervals of the two solenoid valves 302. Specifically, when the multi-stage electric telescopic rod 204 is activated in the forward direction, the right solenoid valve 302 is opened; when the multi-stage electric telescopic rod 204 is activated in the reverse direction, the left solenoid valve 302 is opened. Upon the first cleaning time being reached, the timer controller 4 opens the right solenoid valve 302. When air pump 3 is turned on and multi-stage electric telescopic rod 204 is started in the forward direction, multi-stage electric telescopic rod 204 drives horizontal plate 202 to move to the right. Horizontal plate 202 drives two filter screens 203 to move to the right, so that the left filter screen 203 moves to below the hollow float 107 for application, while the right filter screen 203 moves into the rectangular box 2 on the right. When air pump 3 is started, it supplies air into the loop pipe 301. The air enters the right L-shaped pipe 303 through the solenoid valve 302 on the right, then enters the air distribution box 304 on the right, and then blows downwards through multiple backflush nozzles on the right to backflush the filter screen 203 on the right. When the cleaning and unblocking process reaches its shut-off time, the timer controller 4 controls the air pump 3 and the right-side solenoid valve 302 to close. Waiting for the next cleaning time, the timer controller 4 controls the left-side solenoid valve 302 to open, the air pump 3 to start, and the multi-stage electric telescopic rod 204 to reverse its direction, making the ventilation and movement directions opposite to the above. At this time, the two filters 203 move to the left, causing the right-side filter 203 to move below the hollow float 107 for application, while the left-side filter 203 moves into the left-side rectangular box 2. The gas then flows to the left via the left-side solenoid valve 302. Inside the air distribution box 304 on the left, multiple backflush nozzles on the left blow downwards to backflush and clean the filter screen 203 on the left. When the closing time is reached, the closing operation is performed again. When the cleaning time is reached for the third time, the air distribution box moves to the right again to backflush and clean the filter screen 203 on the right. This process is repeated to achieve the effect of automatic alternating use and alternating backflush cleaning of the two filters 203, ensuring their long-term smooth operation. Through automatic alternating use and cleaning, no personnel are required to disassemble, clean, or maintain the filter screen. This method has a good maintenance-free and long-term smooth operation effect, reducing maintenance frequency and workload.

[0027] The usage method of this embodiment is as follows: When using the maintenance-free automatic air vent valve, the inlet pipe 101 is connected to the upper part of the heating system carrier. Heating system gas is discharged into the valve body 1 through the inlet pipe 101, and then discharged sequentially through the vertical pipe 102 and the exhaust pipe 103. When the water level in the heating system rises and enters the valve body 1, the buoyancy of the liquid causes the hollow float 107 to move upwards. The hollow float 107 causes the upper part of the valve needle 105 to press against the inner side of the conical rubber sleeve 104, performing a sealing and plugging operation, thus automatically ending the venting state and preventing water from entering the vertical pipe 102 and being discharged through the exhaust pipe 103. When the heating system loses water, causing the water level to drop, the hollow float 107 and the counterweight guide rod 106 move downwards under their own weight. The hollow float 107 causes the valve needle 105 to separate downwards from the inner side of the conical rubber sleeve 104, achieving the effect of automatically releasing the seal and allowing airflow when the water level drops due to water loss. This prevents negative pressure from occurring in the heating system, which could affect the safety of the heating system facilities. With the automatic buoyancy-based air closure when the water level rises and the automatic unsealing when the water level falls, allowing for continued ventilation and subsequent air release, the system achieves automated and safe air release and application. Combined with the filter screen 203 to filter solids, it reduces the amount of solids entering the upper part and causing scaling. Furthermore, with the valve needle 105 positioned higher than the bottom of the vertical pipe 102, water will not enter the sealed area inside the vertical pipe 102 or the exhaust pipe 103. Compared to traditional ordinary exhaust valves, this effectively prevents scaling inside the conical rubber sleeve 104 of the exhaust pipe 103, avoiding malfunctions caused by scaling at the ventilation and sealing points that require manual operation and handling. Therefore, it offers the advantage of maintenance-free operation, significantly reducing employee workload and improving user satisfaction. Additionally, because the conical rubber sleeve 104 is made of rubber, it will not rust or solidify under long-term closure with the valve needle 105, preventing malfunctions that could prevent subsequent automatic air release.

[0028] The timer controller 4 is used to preset the start and stop times and intervals of the air pump 3, the forward and reverse directions of the multi-stage electric telescopic rod 204, and the opening and closing times of the two solenoid valves 302. Specifically, when the multi-stage electric telescopic rod 204 is started in the forward direction, the right solenoid valve 302 is controlled to open; when the multi-stage electric telescopic rod 204 is started in the reverse direction, the left solenoid valve 302 is controlled to open. Upon the first cleaning time being reached, the timer controller 4 controls the right solenoid valve 302 to open, the air pump 3 to start, and the multi-stage electric telescopic rod 204 to start in the forward direction. 4. Drive the horizontal sliding plate 202 to move to the right. The horizontal sliding plate 202 drives the two filter screens 203 to move to the right, so that the left filter screen 203 moves to below the hollow float ball 107 for filtration, while the right filter screen 203 moves into the rectangular box 2 on the right. When the air pump 3 starts, it supplies air into the loop pipe 301. The air enters the right L-shaped pipe 303 through the solenoid valve 302 on the right, then enters the air distribution box 304 on the right, and then blows downward through multiple backflush pipes on the right to backflush and clean the filter screen 203 on the right. When the closing time is reached, the timer control is activated. The device 4 controls the air pump 3 and the right solenoid valve 302 to close, waiting for the next cleaning time. Then, the timer controller 4 controls the left solenoid valve 302 to open, the air pump 3 to start, and the multi-stage electric telescopic rod 204 to reverse, so that the ventilation direction and movement direction are opposite to the above. At this time, the two filters 203 move to the left, causing the right filter 203 to move below the hollow float 107 for application, while the left filter 203 moves into the left rectangular box 2. The gas supplied to the left is then fed into the left air distribution box 30 via the left solenoid valve 302. Within 4 hours, multiple backflush nozzles on the left side blow downwards to backflush and clean the filter 203 on the left. When the closing time is reached, the closing operation is performed again. When the cleaning time is reached for the third time, the device moves to the right again to backflush and clean the filter 203 on the right. This process is repeated to achieve the effect of automatic alternating use and alternating backflush cleaning of the two filters 203, ensuring their long-term smooth operation. Through automatic alternating use and cleaning, no personnel are required to disassemble and clean the filters, resulting in a good maintenance-free and long-term smooth application effect, reducing maintenance frequency and workload.

[0029] For the power supply of the solenoid valve 302, timer controller 4, multi-stage electric telescopic rod 204 and air pump 3 in a maintenance-free automatic exhaust valve, a conventional solar power storage assembly consisting of photovoltaic panels, batteries and inverters can be conveniently installed on-site. For example, the photovoltaic panels are connected to the batteries, and the batteries are connected to the inverters. The photovoltaic panels convert solar energy into electrical energy and store it in the batteries. The inverters convert DC power into AC power for power supply.

[0030] Finally, it should be noted that the above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A maintenance-free automatic vent valve comprising a valve body (1), characterized in that: The bottom of the valve body (1) is fixedly connected with an inlet pipe (101), the top of the valve body (1) is fixedly connected with a vertical pipe (102) with a plugging structure at the top end, the right top of the vertical pipe (102) is fixedly connected with an exhaust pipe (103), and the valve body (1) and the vertical pipe (102) are provided with the same floating self-closing air ventilation assembly. The two sides of the valve body (1) are fixedly embedded with rectangular boxes (2), the side close to the two rectangular boxes (2) is provided as an opening, the two rectangular boxes (2) are sealingly and slidingly provided with the same horizontal moving plate (202), the top of the horizontal moving plate (202) is fixedly embedded with two filter screens (203), the top of the filter screen (203) on the right side is in movable contact with the bottom of the floating self-closing air ventilation assembly, the bottom of the rectangular box (2) is provided with a slag discharge hole (201) matched with the corresponding filter screen (203), the bottom left side of the rectangular box (2) on the left side is fixedly connected with a multi-stage electric telescopic rod (204) with the bottom left side of the horizontal moving plate (202) fixedly connected with the extending end, the left top of the valve body (1) is fixedly provided with a timing controller (4), the top of the two rectangular boxes (2) is fixedly embedded with the same alternating switching back flushing and cleaning assembly for alternately back flushing and cleaning the two filter screens (203), and the alternating switching back flushing and cleaning assembly and the multi-stage electric telescopic rod (204) are electrically connected with the timing controller (4).

2. A maintenance-free automatic vent valve according to claim 1, characterized in that: The floating self-closing air ventilation assembly comprises a conical rubber sleeve (104) sleeved in the vertical pipe (102), the valve body (1) is provided with a hollow floating ball (107), the top of the hollow floating ball (107) is fixedly connected with a valve needle (105) with a conical structure at the top end, the valve needle (105) is matched with the inner side of the conical rubber sleeve (104), the top of the hollow floating ball (107) is fixedly connected with a counterweight guide rod (106) on both sides, the top of the valve body (1) is fixedly embedded with two positioning pipes (108) sealingly and slidingly sleeved on the corresponding counterweight guide rods (106), the top end of the positioning pipe (108) is provided as a plugging structure, and the bottom of the hollow floating ball (107) is in movable contact with the top of the filter screen (203) on the right side.

3. A maintenance-free automatic vent valve according to claim 1, wherein: The alternating switching back flushing and cleaning assembly comprises a U-shaped pipe (301) fixedly sleeved outside the valve body (1), the left side of the valve body (1) is fixedly provided with an air outlet, the top of the U-shaped pipe (301) is fixedly connected with an air pump (3), the top of each rectangular box (2) is fixedly embedded with a gas distribution box (304), the bottom of the gas distribution box (304) is fixedly connected with a plurality of back flushing pipe heads, the two sides of the U-shaped pipe (301) are fixedly connected with electromagnetic valves (302), one end of the electromagnetic valve (302) away from the U-shaped pipe (301) is fixedly connected with the same L-shaped pipe (303) between the top of the corresponding gas distribution box (304), and the electromagnetic valve (302) and the air pump (3) are electrically connected with the timing controller (4).

4. A maintenance-free automatic vent valve according to claim 1, wherein: The inner diameter of the exhaust pipe (103) is smaller than that of the vertical pipe (102), and the inner diameter of the vertical pipe (102) is smaller than that of the inlet pipe (101).

5. A maintenance-free automatic vent valve according to claim 2, wherein: The top of the valve body (1) is provided with two vertical guide holes, and a first thin sealing rubber sleeve is attached to the vertical guide holes and in sliding contact with the outer side of the corresponding counterweight guide rod (106).

6. A maintenance-free automatic vent valve according to claim 3, wherein: The inner side of the rectangular box (2) is attached with a second thin sealing rubber sleeve in sliding contact with the outer side of the transverse moving plate (202), the top and bottom of the second thin sealing rubber sleeve are provided with communication holes, and the gas distribution box (304) and the slag discharge hole (201) are vertically aligned with the corresponding communication holes.

7. A maintenance-free automatic vent valve according to claim 1, wherein: The front side and the rear side of the transverse moving plate (202) are in sliding contact with the inner walls of the front side and the rear side of the valve body (1) respectively.

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