High-cleanliness gas circuit control structure

Abstract

The utility model relates to a high-cleanliness gas circuit control structure. The device comprises a filtering pressure reducing valve, a double-acting positioner, a first speed increaser, a second speed increaser, a pressure reducing valve, a one-way valve and a pneumatic actuator, the output end of the filtering pressure reducing valve is connected with an air inlet of the double-acting positioner; the pneumatic actuator is used for controlling opening or closing of the valve and comprises a piston cavity and a piston movably connected into the piston cavity, and the piston cavity is divided into a first cavity body and a second cavity body by the piston. Two control output ports of the double-acting positioner are respectively connected to respective air inlets of the first speed increaser and the second speed increaser; the gas output end of the first speed increaser is connected to the first cavity; the gas output end of the second speed increaser is connected to the second cavity through the pressure reducing valve, and the one-way valve is connected to the pressure reducing valve in parallel. The internal cleaning of the actuator can be effectively ensured, the service life of the actuator is prolonged, and the reliable and stable quality of the sealing surface of the valve is ensured.

Description

TECHNICAL FIELD

[0001] The utility model relates to valve technical field especially is a kind of high-purity gas path control structure. BACKGROUND

[0002] With the continuous investment and construction of key industries such as petroleum and natural gas, petrochemical, environmental protection, electric power, metallurgy, higher requirements are put forward for the performance stability, reliability and ability to adapt to complex environment of various automation control equipment. In the process control system, pneumatic control valve is widely used in automatic regulation of fluid parameters, and its actuator part is usually driven by compressed air to complete opening and closing operation, which is an important terminal execution mechanism for realizing closed-loop control.

[0003] In the prior art, the traditional pneumatic actuator control structure usually adopts single-acting positioner combined with single-side air source control, as shown in FIG. Figure 3 It mainly includes filter pressure reducing valve 1, single-acting positioner 2, speed increaser 3 and actuator 4. Taking reaction mode as an example, when the control signal rises, the controller outputs the gas signal to open the valve; when the signal decreases or fails, the air source is cut off, and the actuator is reset by the internal spring force to close the valve. In this process, the cavity on one side of the actuator needs to be connected with the outside through the exhaust port to inhale external air to complete volume compensation.

[0004] However, in high-purity requirement or harsh industrial site environment, such as high dust, corrosive gas, humid medium and the like, the external air suction path will inevitably introduce pollutants, causing problems such as internal wear of the actuator, sealing failure, response delay and the like, thereby reducing the system operation reliability and the service life of the execution mechanism. At the same time, the traditional structure lacks precise regulation of the air supply pressure of the actuator, which may cause excessive compression when the valve is closed, affecting the service life of the sealing pair and reducing the sealing stability. SUMMARY

[0005] Therefore, the utility model provides a kind of high-purity gas path control structure, when external environment is more harsh, can effectively guarantee the internal cleanliness of actuator, improve the service life of actuator, and guarantee that valve sealing surface quality is reliable and stable.

[0006] To solve the above technical problems, the utility model provides a kind of high-purity gas path control structure, comprising filter pressure reducing valve, double-acting positioner, first speed increaser, second speed increaser, pressure reducing valve, check valve and pneumatic actuator.

[0007] The output end of the filter pressure reducing valve is connected to the air inlet of the double-acting positioner.

[0008] The pneumatic actuator is used for controlling opening or closing of a valve, comprising a piston cavity and a piston movably connected in the piston cavity, the piston divides the piston cavity into a first cavity and a second cavity;

[0009] The two control outputs of the double-acting positioner are connected to the respective air inlets of the first speed increaser and the second speed increaser respectively, and the double-acting positioner can adjust the gas output of the first speed increaser and the second speed increaser according to an input control signal;

[0010] The gas output end of the first speed increaser is connected to the first cavity;

[0011] The gas output end of the second speed increaser is connected to the second cavity through the pressure reducing valve, and the check valve is connected to the pressure reducing valve in parallel.

[0012] In an embodiment of the utility model, the input control signal is a 4-20 mA direct current signal or an FF field bus signal.

[0013] In an embodiment of the utility model, the first speed increaser and the second speed increaser are respectively used for controlling opening and closing actions of the valve of the pneumatic actuator, wherein the first speed increaser controls the piston to move to the valve opening direction, and the second speed increaser controls the piston to move to the valve closing direction.

[0014] In an embodiment of the utility model, the pressure reducing valve can control the pressure entering the second cavity to be below 0.1 MPa.

[0015] In an embodiment of the utility model, the pneumatic actuator further comprises a crank, a spring cavity and a spring arranged in the spring cavity, the piston is connected with a driving rod, the driving rod is connected with a sliding block, the driving rod is connected with the spring, the crank is provided with a sliding groove for sliding of the sliding block, and the crank is connected to a driving shaft of the valve.

[0016] The above technical scheme of the utility model has the following advantages compared with the prior art:

[0017] The high-cleanliness gas path control structure can effectively ensure the cleanliness inside the actuator and prolong the service life of the actuator without inhaling gas from the outside environment when the external environment is relatively harsh, and the pressure reducing valve and the check valve are further arranged, the pressure reducing valve can ensure that the gas pressure entering the actuator is not too high, the valve can be effectively protected from being closed too much at the full-closed position, and the quality of the valve sealing surface is reliable and stable, and the check valve can ensure that the pipeline can smoothly discharge excess gas when the positioner adjusts the signal. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to make the content of the utility model more easily be clearly understood, the following according to the specific embodiment of the utility model and combining with the drawings, the utility model is further detailed.

[0019] Figure 1 It is the schematic diagram of the high cleanliness gas path control structure of the utility model.

[0020] Figure 2 It is the structural schematic diagram of the actuator.

[0021] Figure 3 It is the schematic diagram of the prior art gas path control structure.

[0022] Description of the drawings of the specification:

[0023] 10, filter pressure reducing valve;20, double-acting positioner;30, first speed increaser;40, second speed increaser;50, pressure reducing valve;60, check valve;70, actuator;701, piston cavity;701a, first cavity;701b, second cavity;702, piston;703, spring cavity;704, spring;705, drive rod;706, slider;707, sliding slot;708, crank;80, valve. Specific embodiments

[0024] The utility model is further explained in connection with the drawings and specific embodiments, so that the person skilled in the art can better understand the utility model and can be implemented, but the embodiment is not as the limitation of the utility model.

[0025] In the utility model, if the direction (up, down, left, right, front and back) is described, it is only for the convenience of describing the technical scheme of the utility model, and is not indicated or implied that the indicated technical features must have a specific orientation, a specific orientation structure and operation, so it cannot be understood as the limitation of the utility model.

[0026] In the utility model, the meaning of "several" is one or more, the meaning of "multiple" is two or more, "more than" "less than" "exceed" and the like are understood as not including the number;"above" "below" "within" and the like are understood as including the number. In the description of the utility model, if "first" "second" is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or implicitly indicating the sequence of indicated technical features.

[0027] In the utility model, unless otherwise explicitly limited, the words such as ''set'', ''install'', ''connect'' should be understood in a broad sense, for example, can be directly connected, also can be indirectly connected through intermediate medium, can be fixedly connected, also can be detachably connected, can be integrally formed, can be mechanically connected, also can be electrically connected or can mutually communicate, can be the intercommunication of two elements or the interaction relationship of two elements.The person skilled in the art can combine the specific content of the technical scheme to reasonably determine the specific meaning of the above words in the utility model.

[0028] Referring to Figure 1 The utility model discloses a high cleanliness gas path control structure, including filter pressure reducing valve 10, double acting positioner 20, first speed increaser 30, second speed increaser 40, pressure reducing valve 50, check valve 60 and pneumatic actuator 70.

[0029] The output of filter pressure reducing valve 10 is connected with the air inlet of double acting positioner 20.

[0030] The pneumatic actuator 70 is used for controlling the opening or closing of valve 80, including piston cavity 701 and piston 702 movably connected in piston cavity 701, and piston 702 divides piston cavity 701 into first cavity 701a and second cavity 701b.

[0031] The two control output ports of double acting positioner 20 are connected with the air inlets of first speed increaser 30 and second speed increaser 40 respectively, and double acting positioner 20 can adjust the gas output of first speed increaser 30 and second speed increaser 40 according to input control signal.

[0032] The gas output end of first speed increaser 30 is connected with first cavity 701a.

[0033] The gas output end of second speed increaser 40 is connected with second cavity 701b through pressure reducing valve 50, and check valve 60 is connected with pressure reducing valve 50 in parallel.

[0034] In an embodiment, the input control signal is 4-20mA direct current signal using HART (Highway Addressable Remote Transducer) protocol signal or signal transmitted by FF (Foundation Fieldbus) field bus.

[0035] In one embodiment, the first speed increaser 30 and the second speed increaser 40 are respectively used for controlling the opening and closing actions of the valve 80 of the pneumatic actuator 70, wherein the first speed increaser 30 controls the piston 702 to move to the opening direction of the valve 80, and the second speed increaser 40 controls the piston 702 to move to the closing direction of the valve 80.

[0036] In one embodiment, the pressure reducing valve 50 can control the pressure entering the second cavity 701b to be below 0.1 MPa, so that the pressure of the gas entering the actuator cannot be too high, and the valve 80 can be effectively protected from being closed too much when the valve 80 is fully closed, so as to ensure that the sealing surface quality of the valve 80 is reliable and stable. The one-way valve can ensure that the pipeline can smoothly discharge excess gas when the positioner adjusts the signal. The utility model can greatly reduce the influence of the external environment on the actuator element and prevent the pressure of the gas circuit itself from damaging the actuator element.

[0037] In one embodiment, referring to Figure 2 The pneumatic actuator 70 further comprises a crank 708, a spring cavity 703 and a spring 704 arranged in the spring cavity 703, the piston 702 is connected with a driving rod 705, the driving rod 705 is connected with a sliding block 706, the driving rod 705 is connected with the spring 704, the crank 708 is provided with a sliding groove 707 for sliding of the sliding block 706, and the crank 708 is connected to a driving shaft of the valve 80.

[0038] In the action mode, the utility model works as follows:

[0039] When the signal increases, the valve is required to be opened, at this time, the air inlet of the filter pressure reducing valve is inhaled, the inlet pressure is greater than or equal to 400 KPa, the double-acting positioner 20 gives an electric signal, and the gas flows to the inlets of the double-acting positioner 20, the first speed increaser 30 and the second speed increaser 40 through the pipeline. At this time, the signal of the signal port 1 / 2 of the double-acting positioner 20 is adjusted to correspond to the signal, so that the gas amount of the first speed increaser 30 entering the first cavity 701a of the actuator 70 is increased, the gas amount of the second speed increaser 40 entering the second cavity 701b of the actuator 70 is reduced, the piston 702 of the actuator 70 drives the crank 708 to rotate counterclockwise, at this time, the valve 80 is opened and normally works. When the valve 80 needs to be closed, the signal of the signal port 1 / 2 of the positioner is adjusted to correspond to the signal, so that the gas amount of the first speed increaser 30 entering the first cavity 701a of the actuator 70 is reduced, the gas amount of the second speed increaser 40 entering the second cavity 701b of the actuator 70 is increased, the piston 702 of the actuator 70 drives the crank 708 to rotate clockwise, at this time, the valve 80 is closed and does not inhale air from the outside.

[0040] Compared with the prior art, the high-purity gas path control structure does not need to inhale gas from the outside, can effectively ensure the internal cleanliness of the actuator 70 when the external environment is relatively harsh, prolongs the service life of the actuator 70, and simultaneously increases the pressure reducing valve 50 and the one-way valve 60, the pressure reducing valve 50 can ensure that the gas pressure in the actuator 70 on the left side of the actuator 70 does not become too high, can effectively protect the valve 80 from being closed too much when the valve 80 is fully closed, and ensure that the sealing surface quality of the valve 80 is reliable and stable, and the one-way valve 60 can ensure that the pipeline can smoothly discharge excess gas when the positioner adjusts the signal.

[0041] Finally, it should be explained that the above specific embodiments are only used to illustrate the technical solutions of the present application and are not limited. Although the present application has been described in detail with reference to the examples, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application, and they should be included in the scope of the claims of the present application.

Claims

1. A high-cleanliness gas path control structure, characterized in that, Includes a filter pressure reducing valve (10), a double-acting positioner (20), a first speed increaser (30), a second speed increaser (40), a pressure reducing valve (50), a check valve (60), and a pneumatic actuator (70); The output end of the filter pressure reducing valve (10) is connected to the air inlet of the double-acting positioner (20); The pneumatic actuator (70) is used to control the opening or closing of the valve (80), including a piston chamber (701) and a piston (702) movably connected in the piston chamber (701). The piston (702) divides the piston chamber (701) into a first chamber (701a) and a second chamber (701b). The two control output ports of the dual-acting positioner (20) are respectively connected to the air inlets of the first speed increaser (30) and the second speed increaser (40); the dual-acting positioner (20) can adjust the gas output of the first speed increaser (30) and the second speed increaser (40) according to the input control signal; The gas output end of the first speed increaser (30) is connected to the first cavity (701a). The gas output end of the second speed increaser (40) is connected to the second cavity (701b) via the pressure reducing valve (50), and the one-way valve (60) is connected in parallel to the pressure reducing valve (50).

2. The high-cleanliness gas path control structure according to claim 1, characterized in that, The input control signal is a 4-20mA DC signal or an FF fieldbus signal.

3. The high-cleanliness gas path control structure according to claim 1, characterized in that, The first speed increaser (30) and the second speed increaser (40) are respectively used to control the opening and closing actions of the valve (80) of the pneumatic actuator (70), wherein the first speed increaser (30) controls the piston (702) to move in the opening direction of the valve (80), and the second speed increaser (40) controls the piston (702) to move in the closing direction of the valve (80).

4. The high-cleanliness gas path control structure according to claim 3, characterized in that, The pressure reducing valve (50) can control the pressure entering the second chamber (701b) to below 0.1 MPa.

5. The high-cleanliness gas path control structure according to claim 1, characterized in that, The pneumatic actuator (70) further includes a crank (708), a spring cavity (703), and a spring (704) disposed in the spring cavity (703). The piston (702) is connected to a drive rod (705), the drive rod (705) is connected to a slider (706), the drive rod (705) is connected to the spring (704), the crank (708) is provided with a groove (707) for the slider (706) to slide, and the crank (708) is connected to the drive shaft of the valve (80).

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