Self-recovery liquid level control valve

Abstract

The invention belongs to the technical field of steam heating, and discloses a self-recovery liquid level control valve which comprises an end cover assembly, a valve body, a valve element assembly, a middle auxiliary plate and an air cylinder assembly, the air cylinder assembly is installed on the end cover assembly, an air cylinder piston rod is connected with a valve rod, and the air cylinder assembly does not participate in control under the normal condition. Liquid flows in from the valve inlet, the valve is initially in a closed state, the volume of the liquid is increased, the liquid level rises, buoyancy borne by the valve element is increased, and the valve element is opened when the buoyancy is larger than valve closing pressure. When the valve is opened, liquid is discharged from the outlet, the liquid level of the liquid is continuously reduced, the valve cannot be closed immediately when the liquid flows out, and the valve is closed until the liquid level is reduced to a certain height; an upper liquid level sensor and a lower liquid level sensor are installed in the valve, the valve is not closed when the liquid level is lower than a lower limit, the air cylinder forcibly closes the valve, the valve is not opened when the liquid level is higher than an upper limit, the air cylinder forcibly opens the valve, and opening and closing of the valve are fed back by a proximity switch on the air cylinder assembly.

Description

Technical Field

[0001] The present invention belongs to but is not limited to the technical field of steam heating, and in particular relates to a self-resetting liquid level control valve. Background Art

[0002] Steam heating is a very important heating method. It is widely used for its fast heat transfer, high efficiency and easy control. However, the energy consumption of steam heating is very high. Steam produces condensed water during the heating process. The content of condensed water affects the heating efficiency. In order to ensure the steam heating effect, condensed water needs to be discharged. If the condensed water is not discharged in time, the heating efficiency will be affected. Excessive discharge will be mixed with steam and cause a lot of steam waste. In order to ensure heating efficiency while taking into account low energy consumption, it is necessary to use a reliable liquid level control valve.

[0003] In view of the above analysis, the technical problems that urgently need to be solved in the prior art are: untimely discharge of condensed water affects the heating efficiency, and excessive discharge will be mixed with steam and cause a large amount of steam waste. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a self-resetting liquid level control valve to reduce energy consumption in a heating method using steam.

[0005] The present invention is implemented as follows: a self-resetting liquid level control valve includes an intermediate auxiliary plate, the upper side and lower side of the intermediate auxiliary plate are respectively equipped with an end cover assembly and a valve body, the intermediate auxiliary plate, the end cover assembly and the valve body are fastened with screws, the intermediate auxiliary plate and the valve body are sealed by an O-type seal, the center hole of the intermediate auxiliary plate is sealed with a packing, and the liquid will not leak when the valve core assembly moves up and down. The valve is initially in a normally closed state, and the liquid flows into the valve from the valve inlet. After the liquid level continues to increase and reaches a certain liquid level, the valve opens and the liquid is discharged from the valve outlet. The closing and opening of the valve are fed back by a proximity switch signal, and an upper limit liquid level sensor and a lower limit liquid level sensor are provided in the valve body. When the liquid level is lower than the lower limit or higher than the upper limit, the valve is not closed or opened, and the controller controls the cylinder assembly to force the valve to close or open.

[0006] Furthermore, the valve core assembly includes a valve stem, a float, a support pad, a valve core seal, a clamping pad, a gasket and a nut. In the initial state, the valve core assembly closes the valve. At this time, the valve core seal and the center hole of the valve body are tightly pressed together. The valve stem is equipped with a float. The liquid level inside the valve continues to rise, and the buoyancy of the float continues to increase. When the buoyancy overcomes the pressure of closing the valve, the valve core assembly moves upward rapidly, and the valve is thereby opened.

[0007] Further, the valve core assembly moves upward until the spherical surface of the round head pin fits with the concave surface of the valve stem. The round head pin locks the valve stem under the push of the spring force, and the valve core assembly stops moving and remains stationary. At this time, the valve remains open and the liquid flows out from the valve outlet.

[0008] Furthermore, the end cover assembly includes an end cover, a round pin, a spring and a plug. The four side holes of the end cover are evenly distributed. In terms of structure and function, each hole has a plug pushing a spring inside it, and the spring pushes the round pin. Under the action of the spring force, the spherical surface of the round pin fits radially with the valve stem. The plug can adjust the thrust of the round pin. The greater the thrust, the greater the buoyancy required by the valve core assembly when the valve is opened, and vice versa when the valve is closed.

[0009] Furthermore, when the liquid flows out of the valve outlet, the buoyancy becomes smaller, but the valve stem assembly does not immediately move downward to close the valve. As the liquid level decreases, the buoyancy gradually decreases. When the sum of the gravity of the valve core assembly and the spring pressure is greater than the sum of the total resistance of the four round pins and the buoyancy, the valve core assembly moves downward to close the valve.

[0010] Furthermore, the cylinder assembly includes a proximity switch and a proximity switch. The plug is welded to a mounting frame, and the cylinder assembly, the proximity switch and the proximity switch are fixed on the mounting frame. The proximity switch feedbacks the maximum opening of the valve (fully open). When the liquid level reaches the upper limit (feedback from the liquid level sensor), the proximity switch has no feedback signal, and the controller briefly forces the valve to open through the cylinder; when the valve is enabled, the proximity switch feedbacks that the valve is closed. When the liquid level is lower than the lower limit (feedback from the liquid level sensor), the controller briefly forces the valve to close through the cylinder.

[0011] Furthermore, the valve body is connected by flanges, and a lower limit liquid level sensor and an upper limit liquid level sensor are installed in the cavity inside the valve body.

[0012] Furthermore, in actual use, it is inevitable that the valve stem will get stuck when it moves to a certain point. The cylinder can force the valve to open or close with the help of external force to eliminate the sticking situation and reduce the time for fault finding and maintenance. The feedback signal of the liquid level sensor and proximity switch can transmit the valve status and alarm the fault type when an abnormality occurs.

[0013] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the present invention are as follows:

[0014] First, the valve structure is equipped with a sensor to monitor the liquid level and a proximity switch to feedback whether the valve is open or closed. The valve also has a cylinder component for forced opening or closing. When the liquid level is higher than the upper limit and the valve is not open, the cylinder forces the valve to open; when the liquid level is lower than the lower limit and the valve is not closed, the cylinder forces the valve to close.

[0015] The present invention connects the valve to the control end, monitors the open or closed state of the valve in real time, and can control the cylinder to intervene in the working state of the valve in abnormal situations. When the valve works normally, the valve is opened or closed by its own technical structure, ensuring that the liquid opens when it reaches a certain level and closes when it reaches a certain level, and the cylinder does not participate in the control.

[0016] Second, in the existing liquid level control valve technology, the valve is prone to problems such as liquid leakage, valve core stagnation and inaccurate liquid level monitoring during use, resulting in unstable opening and closing of the valve, which in turn affects the normal operation of the entire system. In addition, the operation of valves in the existing technology is mostly manual or simple automatic control, lacking a precise feedback system and automatic adjustment function, and unable to cope with liquid level changes in complex working conditions, especially in terms of float control accuracy and valve response speed.

[0017] The present invention successfully solves the problems of poor sealing, valve core sticking and inaccurate liquid level control of traditional liquid level control valves by designing a self-resetting liquid level control valve. The device introduces a float to control the opening and closing of the valve core, and combines the forced control function of the cylinder assembly to ensure that the valve can be opened or closed in a timely and reliable manner at the upper and lower limit liquid levels. In addition, the valve adopts a multi-layer sealing and feedback mechanism inside, which greatly reduces the risk of liquid leakage and enhances the stability and safety of the overall system.

[0018] Compared with the traditional liquid level control valve, the present invention has achieved a number of significant technical advances. First, the design of the linkage between the float and the valve core improves the automation of the liquid level control and reduces the intervention of manual operation. Second, the forced switching function of the cylinder assembly effectively solves the problem of valve core jamming and ensures the reliability of the valve under complex working conditions. Third, the linkage feedback system of the liquid level sensor and the proximity switch can monitor the valve status in real time, provide more accurate liquid level control and fault alarm functions, and improve the intelligence level of the system.

[0019] The present invention has significant application prospects in the field of industrial automation liquid level control, especially in scenarios where high-precision liquid level control is required, such as chemical, pharmaceutical, petroleum and other industries. Its automated and intelligent design greatly improves the efficiency and safety of system operation and reduces manual intervention and maintenance costs. In addition, through precise control and feedback systems, the liquid level control valve can work stably for a long time, significantly reducing downtime caused by equipment failure, and providing efficient and reliable liquid level control solutions for related industries. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a structural diagram of a self-resetting liquid level control valve provided by an embodiment of the present invention;

[0021] Figure 2This is a working principle diagram of the self-resetting liquid level control valve provided by an embodiment of the present invention when it is closed;

[0022] Figure 3 This is a working principle diagram of the self-resetting liquid level control valve provided by an embodiment of the present invention when it is opened;

[0023] Figure 4 It is a temperature-pressure variation curve diagram of the heater during the process of valve closing to opening provided by an embodiment of the present invention;

[0024] Figure 5 is a temperature-pressure variation curve diagram of each valve discharge completion provided by an embodiment of the present invention;

[0025] Figure 6 It is a unit consumption variation curve diagram provided by an embodiment of the present invention;

[0026] Figure 7 It is a schematic diagram of a unit consumption change curve provided by an embodiment of the present invention;

[0027] In the figure: 001, O-ring seal; 002, packing seal; 003, plug; 004, spring; 005, screw; 006, upper limit liquid level sensor; 007, liquid level sensor; 100, valve body; 200, intermediate auxiliary plate; 300, end cover assembly; 301, end cover; 302, round head pin; 303, spring; 304, plug; 400, valve core assembly; 401, valve stem; 402, float; 403, support pad; 404, valve core seal; 405, clamping pad; 406, gasket; 407, nut; 500, cylinder assembly; 501, proximity switch; 502, proximity switch. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0029] Example 1: Application in a tank level control system in a chemical plant

[0030] In the liquid level control of storage tanks in chemical plants, liquid needs to be transferred between different storage tanks according to production needs. Traditional liquid level control valves may cause liquid leakage or unstable flow due to poor sealing or valve core jamming during liquid transmission. The self-resetting liquid level control valve provided by the present invention solves these problems.

[0031] In this application, the liquid level of the tank is monitored in real time by the liquid level sensor. When the liquid level of the tank reaches the set upper limit, the buoyancy of the float pushes the valve core assembly upward, the valve automatically opens, and the liquid flows out. At the same time, the proximity switch feedbacks the opening status of the valve to ensure smooth discharge of the liquid. When the liquid level drops to the set lower limit, the liquid level sensor and proximity switch cooperate to control the valve to close to avoid over-limit or under-limit of liquid. In addition, the cylinder assembly provides a forced switch function when the valve core moves unsmoothly, ensuring the stable operation of the system in a complex chemical environment and reducing maintenance requirements.

[0032] Example 2: Application in the automatic liquid level control system of a sewage treatment plant

[0033] In the automatic level control system of sewage treatment plants, accurate control of the liquid level of each treatment tank is an important part of ensuring treatment efficiency. When traditional valves control the sewage level, due to impurities in the sewage, it is easy to cause valve core jamming and valve failure, affecting the entire sewage treatment process.

[0034] The self-resetting liquid level control valve of the present invention controls the liquid level through a float ball, and is combined with the forced switching function of the cylinder assembly to effectively deal with the problems of impurities and floating objects in sewage. The liquid level sensor monitors the liquid level of each treatment tank in real time. When the liquid level reaches the set upper limit, the valve automatically opens to discharge sewage. When the liquid level drops to the set lower limit, the valve automatically closes to maintain a suitable liquid level in the treatment tank. The cylinder assembly can be forced to start when impurities cause the valve to get stuck, avoiding the failure problem of traditional valves. In addition, the liquid level sensor and proximity switch provide reliable real-time feedback and alarm functions, ensuring the stable operation of the sewage treatment process.

[0035] The self-resetting liquid level control valve provided in the embodiment of the present invention comprises an intermediate auxiliary plate 200, the upper side and lower side of the intermediate auxiliary plate 200 are respectively equipped with an end cover assembly 300 and a valve body 100, the intermediate auxiliary plate 200, the end cover assembly 300 and the valve body 100 are fastened by screws 005, the intermediate auxiliary plate 200 and the valve body 100 are sealed by an O-type seal 001, the center hole of the intermediate auxiliary plate 200 is equipped with a packing seal 002, and the liquid will not leak when the valve core assembly 400 moves up and down. The valve is initially in a normally closed state, and the liquid flows into the valve from the valve inlet. After the liquid level continues to increase and reaches a certain liquid level, the valve opens and the liquid is discharged from the valve outlet. The closing and opening of the valve are fed back by the proximity switch signal, and the valve body is provided with an upper limit liquid level sensor 006 and a lower limit sensor 007. When the liquid level is lower than the lower limit or higher than the upper limit, the valve is not closed or opened, and the controller controls the cylinder assembly 500 to force the valve to close or open.

[0036] The valve core assembly 400 includes a valve stem 401, a float 402, a support pad 403, a valve core seal 404, a clamping pad 405, a gasket 406 and a nut 407. In the initial state, the valve core assembly 400 closes the valve. At this time, the valve core seal 404 and the center hole of the valve body 100 are tightly pressed together. The valve stem 401 is equipped with a float 402. The liquid level inside the valve continues to rise, and the buoyancy of the float 402 continues to increase. When the buoyancy overcomes the pressure of the valve closing, the valve core assembly 400 moves upward quickly, and the valve is opened.

[0037] The valve core assembly 400 moves upward until the spherical surface of the round pin 302 fits with the concave surface of the valve stem 401. The round pin 302 locks the valve stem 401 under the push of the spring force, and the valve core assembly 400 stops moving and remains stationary. At this time, the valve remains open and the liquid flows out from the valve outlet.

[0038] The end cover assembly 300 includes an end cover 301, a round pin 302, a spring 303 and a plug 304. The four side holes of the end cover 301 are evenly distributed. In terms of structure and function, each hole is pushed by the plug 304 to push the spring 303, and the spring 303 pushes the round pin 302. Under the action of the spring force, the spherical surface of the round pin 302 is radially fitted with the valve stem 401. The plug 304 can adjust the thrust of the round pin 302. The greater the thrust, the greater the buoyancy required by the valve core assembly 400 when the valve is opened, and vice versa when the valve is closed.

[0039] When the liquid flows out of the valve outlet, the buoyancy decreases, but the valve stem assembly 400 does not immediately move downward to close the valve. As the liquid level decreases, the buoyancy gradually decreases. When the sum of the gravity of the valve core assembly 400 and the pressure of the spring 004 is greater than the sum of the total resistance of the four round pins 302 and the buoyancy, the valve core assembly 400 moves downward to close the valve.

[0040] The cylinder assembly 500 includes a proximity switch 501 and a proximity switch 502. The plug 003 is welded to a mounting frame, and the cylinder assembly 500, the proximity switch 501 and the proximity switch 502 are fixed on the mounting frame. The proximity switch 501 feedbacks the maximum opening of the valve (fully open). When the liquid level reaches the upper limit (feedback from the liquid level sensor 006), the proximity switch 501 has no feedback signal, and the controller temporarily forces the valve to open through the cylinder; when the valve is enabled, the proximity switch 502 feedbacks that the valve is closed. When the liquid level is lower than the lower limit (feedback from the liquid level sensor 007), the controller temporarily forces the valve to close through the cylinder.

[0041] The valve body 100 is connected by flanges, and a lower limit liquid level sensor 007 and an upper limit liquid level sensor 006 are installed in the cavity inside the valve body.

[0042] In actual use, it is inevitable that the valve stem will get stuck when it moves to a certain point. The cylinder can force the valve to open or close with the help of external force to eliminate the sticking situation and reduce the time for fault finding and maintenance. The feedback signal of the liquid level sensor and proximity switch can transmit the valve status and alarm the fault type when an abnormality occurs.

[0043] The self-resetting liquid level control valve provided by the present invention forms an integral structure by fastening the intermediate auxiliary plate 200, the end cover assembly 300 and the valve body 100. The O-type seal 001 is used to seal the joint surface between the intermediate auxiliary plate 200 and the valve body 100 to ensure that the liquid does not leak when the valve core assembly 400 moves up and down. The initial state of the valve is normally closed, and the liquid enters through the valve inlet. As the liquid level continues to increase, when the liquid level reaches the preset upper limit, the buoyancy generated by the float 402 overcomes the pressure of closing the valve, pushes the valve core assembly 400 to move upward, the valve opens, and the liquid is discharged from the outlet. The entire system realizes the automatic discharge of liquid and the switching of valve opening and closing through sealing and buoyancy control.

[0044] The valve core assembly 400 includes a valve stem 401 and a float 402. The buoyancy of the float is a key factor in controlling the opening of the valve. As the liquid level rises, the buoyancy of the float increases. When the buoyancy is sufficient to overcome the pressure when the valve is closed, the valve core assembly 400 moves upward and the valve opens. When the valve is opened, the float pushes the valve stem upward until the spherical surface of the round pin 302 fits the concave surface of the valve stem, and the valve core assembly 400 is locked under the action of the spring 303, keeping the valve in an open state, and the liquid flows out from the outlet until the liquid level drops to the lower limit.

[0045] When the valve core assembly 400 moves up to the open state, the locking device composed of the round pin 302 and the spring 303 fixes the valve stem. The round pin is pushed toward the valve stem by the spring to ensure its stability. The plug 304 changes the buoyancy required for opening and closing the valve by adjusting the thrust of the spring. This design ensures that the valve can be opened smoothly when the float moves up, and when the liquid level drops, the buoyancy gradually decreases. When the buoyancy of the valve core assembly 400 is less than the sum of gravity and spring pressure, the valve core assembly moves downward to close the valve.

[0046] In order to avoid the valve core from getting stuck due to friction and other reasons during movement, the cylinder assembly 500 can force the valve to open or close by external force. When the liquid level sensor 006 or 007 feedbacks the upper limit or lower limit signal, the controller makes a judgment based on the signals of the proximity switches 501 and 502, and the cylinder assembly can intervene with a short external force to keep the valve running normally and eliminate the problem of sticking. This function reduces the need for manual intervention and improves the reliability and working efficiency of the valve.

[0047] Liquid level sensors 006 and 007 are installed in the valve body to monitor the upper and lower limits of the liquid level. When the liquid level reaches the upper or lower limit, the sensor feeds back the signal to the controller, and the controller determines whether the valve needs to be opened or closed based on the feedback signal. At the same time, proximity switches 501 and 502 are also used to feedback the status of the valve to ensure that the status of the valve when it is fully opened or closed is clear. This linkage mechanism of sensors and switches can monitor the status of the valve in real time to prevent malfunctions.

[0048] When an abnormality occurs during valve operation, such as failure to open or close normally, the system can judge the fault through the feedback signals of the liquid level sensor and the proximity switch. If the liquid level signal does not match the proximity switch signal, the controller will automatically alarm to remind the operator to perform maintenance. This design reduces the time for fault finding and maintenance, improves the safety and maintenance efficiency of the system, and ensures the reliability and stability of the liquid level control valve in actual use.

[0049] The self-resetting liquid level control valve comprises an end cover assembly 300, an O-ring seal 001, a packing seal 002, a plug 003, a spring 004, a screw 005, a liquid level sensor 006, a liquid level sensor 007, a cylinder assembly 500, a valve body 100, a valve core assembly 400 and an intermediate auxiliary plate 200, wherein the condensate generated by steam heating flows from the pipeline into the self-resetting liquid level control valve, the valve is initially in a normally closed state, and the condensate continuously accumulates (see attached Figure 2 ), the liquid level reaches a certain height (the liquid level is determined by the spring force of spring 303 and spring 004), the valve passage is opened, and the valve stem 401 moves up and is locked by the round head pin 302 (see attached Figure 3 ), the condensed water is discharged from the outlet. When the valve is opened, the condensed water is continuously discharged, and the liquid level drops to a certain height. The sum of the spring force of spring 004 and the weight of valve core assembly 400 is greater than the sum of the thrust and buoyancy of spring 303, and the valve stem 401 moves down to close the valve.

[0050] The valve is set with the highest upper limit and the lowest lower limit. When the valve is closed, the condensate level is higher than the lower limit, and the water vapor cannot be discharged through the valve, thereby reducing steam waste. The valve upper limit level sensor 006, the lower limit level sensor 007, the proximity switch 501 and the indirect switch 502 feedback signals to the PLC. When the condensate reaches the lower limit, the valve is not closed, and the PLC controls the cylinder to force the valve to close. The forced control method can avoid steam waste and reduce energy consumption; when the condensate level reaches the upper limit, the valve is not opened, and the PLC will also control the cylinder to force the valve to open. Excessive condensate affects the heating efficiency. Forcing the valve to open can ensure the temperature, especially for the production process of products with high temperature requirements, and can ensure the qualified rate of high-quality products.

[0051] In actual applications, valves are bound to get stuck, which affects normal discharge and takes a lot of time to find. This does not mean that the valve is damaged. As long as the valve stem is pushed out of the sticking point by external force, the valve can be restored to normal use. When the valve opens or closes abnormally, the valve can be reset by using a cylinder to force it to open or close.

[0052] The self-resetting liquid level control valve is an energy-saving and consumption-reducing valve that can be used in piping systems for liquid discharge control. It is suitable for occasions where the discharged liquid has a gradual accumulation process, especially in equipment and pipelines using steam heating. As the heat of steam heating is continuously consumed, the steam will condense into water when it encounters cold. The more water accumulates, the more it will affect the heating effect. The discharge of condensed water is very critical. In order to pay attention to efficiency, both steam heating and energy saving and consumption reduction are often required. The self-resetting liquid level control valve continuously collects the accumulated condensed water and discharges it when the collected condensed water reaches a certain volume. When discharging the condensed water, the steam is isolated and not discharged, which greatly reduces the waste caused by steam discharge. Taking the vulcanizer using steam heating as an example, during the vulcanization process of the tire, steam flows into the hot plate through the pipe to heat the vulcanized tire embryo. The steam will condense into water during the heating process. Excessive accumulation of condensed water in the hot plate will cause the heating effect to deteriorate and the heating temperature to decrease. If the temperature does not meet the process requirements, it will cause waste and defective products. In order to ensure the heating temperature, the condensed water must be discharged. The amount and time of condensed water discharge cannot be controlled. The only option is to ensure the temperature and continuously discharge the condensed water. At this time, the steam will also be discharged, and energy saving and consumption reduction cannot be achieved. The use of a self-resetting liquid level control valve can achieve the goal of only discharging condensed water without wasting steam, truly achieving the effect of energy saving and consumption reduction.

[0053] In nature, whether it is liquid or gas, the material with higher density will be in the lower layer. The density of water is 10 3 kg / m 3 , water vapor at 210℃ and 4MPa is 22.1kg / m 3 , usually the density of steam is much lower than that of water, so the condensed water produced by steam is always at the bottom. In theory, the conversion of steam and condensed water is 1:1, that is, the amount of steam consumed will produce the same quality of condensed water. The self-returning liquid level control valve discharges through the condensed water level. Only condensed water is discharged in the intermediate process without steam. The steam is highly utilized without waste. Efficient use of steam can reduce energy consumption.

[0054] Taking the steam heating of the vulcanizer as an example, condensed water is generated when steam heats the hot plate. The condensed water accumulates gradually and increases. The condensed water is always at the bottom of the hot plate. The condensed water flows into the pipe along the outlet. The condensed water in the pipe is collected and accumulated in the self-resetting liquid level control valve. The larger the volume in the self-resetting liquid level control valve, the more condensed water is collected. The internal water vapor is above the condensed water. When it reaches a certain volume, the valve is opened, and the condensed water will continue to be discharged from the valve discharge port. When the condensed water drops to a certain liquid level, the valve is closed. The valve maintains a certain liquid level throughout the entire working state from opening to closing. The retained condensed water has a sealing effect, and the steam can never escape.

[0055] In order to improve the reliability of the self-resetting liquid level control valve, there are upper and lower limit liquid level sensors inside the valve. The upper limit sensor is to ensure that the water meets the discharge standard and is not discharged due to factors such as sticking, affecting the heating temperature. The lower limit liquid level sensor is to ensure that the condensed water meets the discharge standard and is not closed, causing steam waste. When the upper or lower limit liquid level sensor feedbacks a signal, the control system controls the cylinder to force the valve to open or close. When the cylinder is forced to control, the abnormality caused by short-term valve sticking or back pressure can be eliminated, so that the valve has a certain reset effect, thereby improving the reliability of valve use.

[0056] In the description of the present invention, unless otherwise specified, "plurality" means two or more than two; the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail", etc. are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0057] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A self-resetting liquid level control valve, characterized in that: It includes an intermediate auxiliary plate, on which the upper and lower sides of the intermediate auxiliary plate are respectively assembled with an end cover assembly and a valve body, the intermediate auxiliary plate, the end cover assembly and the valve body are fastened with screws, the intermediate auxiliary plate and the valve body are sealed by an O-ring seal, the center hole of the intermediate auxiliary plate is sealed with a packing, and the liquid will not leak when the valve core assembly moves up and down; the valve is initially in a normally closed state, and the liquid flows into the valve from the valve inlet. After the liquid level continues to increase and reaches a certain liquid level, the valve opens, and the liquid is discharged from the valve outlet; the closing and opening of the valve are fed back by a proximity switch signal, and an upper limit liquid level sensor and a lower limit liquid level sensor are arranged in the valve body. When the liquid level is lower than the lower limit or higher than the upper limit, the valve is not closed or opened, and the controller forces the valve to be closed or opened by controlling the cylinder assembly.

2. The self-resetting liquid level control valve according to claim 1, characterized in that: The valve core assembly includes a valve stem, a float, a support pad, a valve core seal, a clamping pad, a gasket and a nut. In the initial state, the valve core assembly closes the valve. At this time, the valve core seal and the center hole of the valve body are tightly pressed together. The valve stem is equipped with a float. The liquid level inside the valve continues to rise, and the buoyancy of the float continues to increase. When the buoyancy overcomes the pressure of the valve closing, the valve core assembly moves upward rapidly, and the valve is opened.

3. The self-resetting liquid level control valve according to claim 1, characterized in that: The valve core assembly moves upward until the spherical surface of the round head pin fits with the concave surface of the valve stem. The round head pin locks the valve stem under the push of the spring force, and the valve core assembly stops moving and remains stationary. At this time, the valve remains open and the liquid flows out from the valve outlet.

4. The self-resetting liquid level control valve according to claim 1, characterized in that: The end cover assembly includes an end cover, a round head pin, a spring and a plug; the four side holes of the end cover are evenly distributed. In terms of structure and function, the plug pushes the spring inside each hole, and the spring pushes the round head pin. Under the action of the spring force, the spherical surface of the round head pin fits radially with the valve stem; the plug can adjust the thrust of the round head pin. The greater the thrust, the greater the buoyancy required by the valve core assembly when the valve is opened, and the opposite is true when the valve is closed.

5. The self-resetting liquid level control valve according to claim 3, characterized in that: When the liquid flows out of the valve outlet, the buoyancy becomes smaller, but the valve stem assembly does not immediately move downward to close the valve. As the liquid level decreases, the buoyancy gradually decreases. When the sum of the gravity of the valve core assembly and the spring pressure is greater than the sum of the total resistance of the four round pins and the buoyancy, the valve core assembly moves downward to close the valve.

6. The self-resetting liquid level control valve according to claim 1, characterized in that: The cylinder assembly includes a proximity switch and a proximity switch. A mounting bracket is welded to the plug. The cylinder assembly, proximity switch and proximity switch are fixed on this mounting bracket. The proximity switch feedbacks the maximum opening of the valve. When the liquid level reaches the upper limit, the proximity switch has no feedback signal, and the controller briefly forces the valve to open through the cylinder; when the valve is enabled, the proximity switch feedbacks that the valve is closed. When the liquid level is lower than the lower limit, the controller briefly forces the valve to close through the cylinder.

7. The self-resetting liquid level control valve according to claim 1, characterized in that: The valve body is connected by flanges, and a lower limit liquid level sensor and an upper limit liquid level sensor are installed in the cavity of the valve body.

8. The self-resetting liquid level control valve according to claim 6, characterized in that: In actual use, it is inevitable that the valve stem will get stuck when it moves to a certain point. The cylinder can force the valve to open or close with the help of external force to eliminate the sticking situation and reduce the time for fault finding and maintenance. The feedback signal of the liquid level sensor and proximity switch can transmit the valve status and alarm the fault type when an abnormality occurs.

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