Valve positioner

Abstract

The utility model provides a valve positioner, and belongs to the technical field of explosion suppression of valve positioners. The valve positioner comprises a shell, a pneumatic channel, a first explosion-proof cavity and a second explosion-proof cavity are arranged in the shell, the pneumatic channel comprises a first branch channel and a second branch channel, the first branch channel is communicated with the first explosion-proof cavity, and the second branch channel is communicated with the second explosion-proof cavity. The flame can move towards the first explosion-proof cavity through the first branch flow channel, and the flame can move towards the second explosion-proof cavity through the second branch flow channel. According to the valve positioner, the explosion-proof performance of the valve positioner can be improved.

Description

A valve positioner Technical Field

[0001] This utility model relates to the field of explosion-proof technology for valve positioners, and in particular to a valve positioner. Background Technology

[0002] Valve positioners are key components in valve control, forming a basic controllable unit in a production pipeline in conjunction with valves and actuators. Valve positioners control the valve opening and regulate the flow rate of media within the pipeline by controlling the actuator's stroke. With advancements in valve positioner technology, intelligent valve positioners have become market leaders due to their lower maintenance costs and superior interactive performance. However, the emergence of more diverse application scenarios and operating conditions has placed higher demands on the explosion-proof requirements of intelligent valve positioners. Intrinsically safe and explosion-proof valve positioners are the most widely used types.

[0003] In related technologies, valve positioners typically have only one explosion-proof chamber, which means that the flame generated inside the valve positioner can only be blocked within one explosion-proof chamber. This results in a high degree of damage to the explosion-proof chamber by the flame, and the valve positioner can only block the flame for a short time, thus making the explosion-proof performance of the valve positioner poor. Summary of the Invention

[0004] This utility model provides a valve positioner, the purpose of which is to improve the explosion-proof performance of the valve positioner.

[0005] To achieve the above objectives, this utility model provides a valve positioner, including a housing. The housing contains a pneumatic channel, a first explosion-proof chamber, and a second explosion-proof chamber. The pneumatic channel includes a first branch channel and a second branch channel. The first branch channel communicates with the first explosion-proof chamber, and the second branch channel communicates with the second explosion-proof chamber. When a flame is generated inside the housing, the flame can move towards the first explosion-proof chamber through the first branch channel, and the flame can move towards the second explosion-proof chamber through the second branch channel.

[0006] In one embodiment, the pneumatic channel includes a flow divider cavity, the first branch channel and the second branch channel are both connected to the flow divider cavity, the first explosion-proof cavity and the second explosion-proof cavity are respectively located on both sides of the housing along the radial direction of the housing, and the first explosion-proof cavity and the flow divider cavity are located on the same side of the housing along the radial direction of the housing.

[0007] In one embodiment, the valve positioner includes a throttling device disposed within the second branch channel. The throttling device includes a throttling seat and a jewel, the jewel being disposed within the throttling seat. The jewel has a throttling orifice configured to penetrate the jewel along the flow direction of gas within the second branch channel.

[0008] In one embodiment, the valve positioner further includes a sintered filter element disposed within the throttling seat.

[0009] In one embodiment, the valve positioner includes an electrical conversion component and a feedback component. The housing also has a main cavity that is independent of the first explosion-proof cavity. The electrical conversion component is disposed in the main cavity, and the feedback component is disposed in the first explosion-proof cavity.

[0010] In one embodiment, the housing has a wire passage hole, and the main cavity communicates with the first explosion-proof cavity through the wire passage hole, so that the signal line of the feedback component can be connected to the electrical conversion component through the wire passage hole.

[0011] In one embodiment, the housing has a wire passage hole, and the main cavity communicates with the first explosion-proof cavity through the wire passage hole, so that the signal line of the feedback component can be connected to the electrical conversion component through the wire passage hole. The valve positioner also includes a sealing element, which is disposed in the wire passage hole to close the wire passage hole, and the signal line of the feedback component passes through the sealing element.

[0012] In one embodiment, the housing has a through hole communicating with the outside, and the valve positioner further includes a sintered filter element disposed within the through hole.

[0013] In one embodiment, the valve positioner includes a feedback shaft assembly that is threadedly connected to the explosion-proof housing.

[0014] In one embodiment, the outer casing includes a base and a top cover connected to each other. The top cover encloses a main cavity, and the base encloses the pneumatic channel, the first explosion-proof cavity, and the second explosion-proof cavity. The top cover includes explosion-proof glass and a cover body. The cover body is connected to the base, and the explosion-proof glass is disposed on the side of the cover body away from the base.

[0015] The above-mentioned solution of this utility model has the following beneficial effects:

[0016] In this embodiment, when a flame is generated inside the valve positioner, the flame can be diverted within the pneumatic channel to a first branch channel and a second branch channel. A portion of the flame enters the first explosion-proof chamber through the first branch channel and is subsequently blocked by the first explosion-proof chamber, while another portion enters the second explosion-proof chamber through the second branch channel and is subsequently blocked by the second explosion-proof chamber. This ensures that the flame can be blocked in both the first and second explosion-proof chambers. Compared to related technologies where the valve positioner has only one explosion-proof chamber, limiting flame blocking to just one chamber, blocking the flame in both chambers reduces the damage to both chambers, lowers the likelihood of the valve positioner being damaged by the flame, and prolongs the time the outer casing can block the flame when it is generated internally. This reduces the possibility of the flame igniting flammable and explosive gases outside the valve positioner, improving the explosion-proof effect of the valve positioner and enhancing the safety of pipelines carrying flammable and explosive gases.

[0017] Other beneficial effects of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0018] Figure 1 is a schematic diagram of the valve positioner in one embodiment of the present invention from a certain perspective.

[0019] Figure 2 is a top view of the valve positioner in one embodiment of the present invention;

[0020] Figure 3 is a cross-sectional view at point AA in Figure 2. The first and second branch channels are indicated by dashed lines in the figure.

[0021] Figure 4 is a cross-sectional view of section BB in Figure 2;

[0022] Figure 5 is a cross-sectional view of CC in Figure 2;

[0023] Figure 6 is a cross-sectional view of DD in Figure 2;

[0024] Figure 7 is a cross-sectional view of EE in Figure 2.

[0025] [Explanation of Labels in the Attached Image]

[0026] 1. Outer shell; 11. Pneumatic channel; 111. First branch channel; 112. Second branch channel; 113. Diverter chamber; 12. First explosion-proof chamber; 13. Second explosion-proof chamber; 14. Main chamber; 15. Wiring hole; 16. Through hole; 17. Top cover; 171. Explosion-proof glass; 172. Cover body; 18. Base; 19. First end cover; 20. Second end cover; 2. Throttling device; 21. Throttling seat; 22. Gemstone; 3. Sintered filter element; 4. Electrical conversion assembly; 5. Feedback assembly; 6. Feedback shaft assembly; 7. Slide valve; 8. Strike pin; 9. Elastic element; 10. Nozzle. Detailed Implementation

[0027] To make the technical problems, solutions, and advantages of this utility model clearer, a detailed description will be provided below with reference to the accompanying drawings and specific embodiments. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. Furthermore, the technical features involved in the different embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0028] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0029] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a locking connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0030] As shown in FIGS. 1 and 2, an embodiment of the present utility model provides a valve positioner. FIGS. 1 and 2 respectively show the structures of the valve positioner of the present application from different perspectives. The valve positioner of the present application can be an ordinary valve positioner, an explosion-proof valve positioner or an intelligent explosion-proof valve positioner. The valve positioner with explosion-proof function is usually installed on the production pipeline through which flammable and explosive gases pass, and controls the opening degree of the valve stem of the valve by driving an actuator matched with the valve positioner, so as to adjust the flow rate of the flammable and explosive gases in the production pipeline. There is a probability that flames or sparks will be generated inside the explosion-proof valve positioner, and it is necessary for the explosion-proof valve positioner itself to have a good ability to block the diffusion of the internal flame to the flammable and explosive gases outside, so as to reduce the possibility of the internal flame of the explosion-proof valve positioner detonating the flammable and explosive gases and improve the safety of the production pipeline through which flammable and explosive gases pass.

[0031] Please refer to FIG. 3. FIG. 3 is a schematic cross-sectional view of the structure at A-A in FIG. 2, showing the direction of the pneumatic channel 11. Specifically, the valve positioner of the present application includes a housing 1. The material of the housing 1 can be a material with certain strength and stiffness, such as metal. A pneumatic channel 11, a first explosion-proof chamber 12 and a second explosion-proof chamber 13 are provided inside the housing 1. The pneumatic channel 11 includes a first branch channel 111 and a second branch channel 112. The first branch channel 111 is connected to the first explosion-proof chamber 12, and the second branch channel 112 is connected to the second explosion-proof chamber 13. When a flame is generated inside the housing 1, the flame can move through the first branch channel 111 to the first explosion-proof chamber 12, and the flame can move through the second branch channel 112 to the second explosion-proof chamber 13. Among them, both the first explosion-proof chamber 12 and the second explosion-proof chamber 13 can block the flame.

[0032] It should be noted that high-pressure gas is passed through the pneumatic channel 11. The high-pressure gas is used to drive an actuator (not shown in the drawings) matched with the valve positioner to act, and then the actuator can drive the valve stem of the valve to act to adjust the opening degree of the valve. When a flame or spark is generated inside the valve positioner, the flame can move along various channels inside the housing 1, such as the pneumatic channel 11.

[0033] For example, referring to Figure 4, the valve positioner may further include a slide valve 7, a striking pin 8, and an elastic element 9, which may be a spring. The slide valve 7 and the striking pin 8 are both disposed between the first explosion-proof chamber 12 and the second explosion-proof chamber 13. The striking pin 8 is disposed on the side of the slide valve 7 closest to the first explosion-proof chamber 12, and the elastic element 9 is disposed within the second explosion-proof chamber 13. High-pressure gas in the first branch channel 111 is introduced into the first explosion-proof chamber 12 to drive the striking pin 8 to move, thereby enabling the valve core of the slide valve 7 to move. High-pressure gas in the second branch channel 112 is introduced into the second explosion-proof chamber 13, and together with the elastic element 9 located within the second explosion-proof chamber 13, drives the valve core of the slide valve 7 to move. When the forces on the left and right sides of the valve core of the slide valve 7 reach a balanced state, the valve core of the slide valve 7 is stabilized in a preset relative position, and the high-pressure gas can then be injected from the slide valve 7 into the actuator matched with the valve positioner to drive the valve stem to move.

[0034] In this embodiment, when a flame is generated inside the valve positioner, the flame can be diverted within the pneumatic channel 11 to the first branch channel 111 and the second branch channel 112. A portion of the flame enters the first explosion-proof chamber 12 through the first branch channel 111 and is then blocked by the first explosion-proof chamber 12. Another portion of the flame enters the second explosion-proof chamber 13 through the second branch channel 112 and is then blocked by the second explosion-proof chamber 13. This ensures that the flame is blocked in both the first and second explosion-proof chambers 12 and 13, respectively. Compared to related technologies where the valve positioner has only one explosion-proof chamber, allowing the flame to be blocked only within that chamber, blocking the flame in both chambers reduces the damage to the first and second explosion-proof chambers 12 and 13, lowers the likelihood of the valve positioner being damaged by the flame, and prolongs the time the outer casing 1 can block the flame when it is generated inside the valve positioner. This reduces the possibility of the flame igniting flammable and explosive gases outside the valve positioner, improving the explosion-proof effect of the valve positioner and enhancing the safety of pipelines carrying flammable and explosive gases.

[0035] In one embodiment, referring to Figures 3 and 4, the pneumatic channel 11 includes a diversion chamber 113. A first branch channel 111 and a second branch channel 112 are both connected to the diversion chamber 113, allowing the high-pressure gas inside the housing 1 to be diverted at the location of the diversion chamber 113 to the first branch channel 111 and the second branch channel 112, respectively. The first explosion-proof chamber 12 and the second explosion-proof chamber 13 are located on opposite sides of the housing 1 along its radial direction. The first explosion-proof chamber 12 and the diversion chamber 113 are located on the same side of the housing 1 along its radial direction, making the total path of the pneumatic channel 11 longer. This means that when a flame is generated inside the valve positioner, the flame needs to travel a longer distance to reach the first explosion-proof chamber 12 and the second explosion-proof chamber 13, respectively. This helps to dissipate the flame's energy, reducing the damage caused by the flame to the first explosion-proof chamber 12 and the second explosion-proof chamber 13, and improving the explosion-proof effect of the valve positioner.

[0036] For example, in Figures 3 to 7, R1 points to the radial direction of the outer casing 1.

[0037] For example, referring to Figure 3, the valve positioner may include a nozzle 10, which, as shown in Figure 3, is located in the middle of the housing 1. One end of the pneumatic channel 11, away from the first explosion-proof chamber 12 and the second explosion-proof chamber 13, is connected to the nozzle 10. High-pressure gas enters the pneumatic channel 11 from the nozzle 10, first flowing to the lower right into the diversion chamber 113, then flowing downwards through the first branch channel 111 to the first explosion-proof chamber 12, and then flowing to the lower left into the second explosion-proof chamber 13 through the second branch channel 112. This results in a long flow path for the high-pressure gas, with multiple bends. When a flame is generated within the valve positioner, the flame also needs to travel a long flow path to reach the first explosion-proof chamber 12 and the second explosion-proof chamber 13, which helps to dissipate the flame's energy.

[0038] It is understood that the relative positional relationship between the first explosion-proof cavity 12, the second explosion-proof cavity 13, and the diversion cavity 113 is not limited. For example, the second explosion-proof cavity 13 may also be located on the same side of the outer shell 1 along the radial direction of the outer shell 1 as the diversion cavity 113, or the first explosion-proof cavity 12, the second explosion-proof cavity 13, and the diversion cavity 113 may all be located on the same side of the outer shell 1 along the radial direction of the outer shell 1.

[0039] In one embodiment, referring to Figure 3, the valve positioner includes a throttling device 2 disposed within a second branch channel 112. The throttling device 2 is used to throttle and reduce the pressure of the high-pressure gas within the second branch channel 112. The throttling device 2 includes a throttling seat 21 and a gemstone 22, with the gemstone 22 disposed within the throttling seat 21 to fix it in place. The gemstone 22 has a throttling orifice configured to penetrate the gemstone 22 along the gas flow direction within the second branch channel 112, allowing the high-pressure gas to flow through the throttling orifice into the second explosion-proof cavity 13. This also allows the gemstone 22 to at least partially block the flame located within the second branch channel 112, thereby reducing the flame propagation into the second explosion-proof cavity 13 and reducing the degree of damage to the second explosion-proof cavity 13 by the flame, which is beneficial to improving the explosion-proof effect of the valve positioner.

[0040] For example, the gemstone 22 has a preset shape and material properties to control the flow direction and flow rate of the high-pressure gas in the second branch channel 112. When the high-pressure gas passes through the gemstone 22, the throttling orifice of the gemstone 22 can form a certain resistance, thereby slowing down the flow rate of the fluid to achieve the purpose of throttling and pressure reduction.

[0041] For example, the orifice diameter of the jewel 22 can be 0.3 mm, so that high-pressure gas can flow through the orifice of the jewel 22 into the second explosion-proof cavity 13, and also so that the jewel 22 can at least block part of the flame located in the second branch channel 112.

[0042] In one embodiment, referring to Figure 3, the valve positioner further includes a sintered filter element 3, which is disposed within the throttling seat 21. For example, the sintered filter element 3 can be disposed on the side of the jewel 22 facing away from the diversion chamber 113. The sintered filter element 3 can be made of sintered metal powder filter element, which can block the propagation of flame. Combined with the jewel 22, it further improves the valve positioner's performance in blocking the spread of flame to the outside, which is beneficial to improving the valve positioner's explosion-proof capability. The sintered filter element 3 can allow gas to pass through in both directions to maintain the gas pressure balance on both sides of the sintered filter element 3, or it can allow gas to pass through in only one direction.

[0043] It is understood that the valve positioner is not limited to including the sintered filter element 3. Exemplarily, at least part of the flame propagation can be blocked within the second branch channel 112 by means of the throttling device 2 alone.

[0044] In one embodiment, referring to Figure 4, the valve positioner includes an electrical conversion component 4 and a feedback component 5. The electrical conversion component 4 is used to convert a current or voltage signal into a linearly proportional pneumatic signal output, and can be, for example, an electrical converter. The feedback component 5 is used to provide feedback on the position of the slide valve 7 located between the first explosion-proof chamber 12 and the second explosion-proof chamber 13, and can be, for example, an induction coil capable of sensing the position of the slide valve 7. The housing 1 also has a main chamber 14 independent of the first explosion-proof chamber 12. The electrical conversion component 4 is disposed in the main chamber 14, and the feedback component 5 is disposed in the first explosion-proof chamber 12. The electrical conversion component 4 and the feedback component 5 are located in different chambers, eliminating the need for a large-volume cavity within the housing 1 to encapsulate various functional components. Compared to other systems where all functional components are housed in the same cavity, the electrical conversion component 4 and the feedback component 5 are located in different cavities. This makes the installation of the electrical conversion component 4 and the feedback component 5 more convenient, and also facilitates subsequent testing and maintenance. On the other hand, it allows the volume of the main cavity 14 and the first explosion-proof cavity 12 to be reduced relative to a larger cavity. Under the same explosion-proof requirements, the thickness of the outer shell 1 corresponding to the smaller cavity can be less than that of the larger cavity. Consequently, the thickness of the outer shell 1 corresponding to the main cavity 14 and the first explosion-proof cavity 12 can be reduced, which helps to reduce the overall weight of the valve positioner and improve its economic efficiency.

[0045] Generally, an electrical conversion component 4 is provided in the main cavity 14. The electrical conversion component 4 may include a control circuit board and a solenoid valve, etc. Therefore, a flame may be generated in the main cavity 14. The flame can move to the first explosion-proof cavity 12 through the first branch channel 111, and can also move to the second explosion-proof cavity 13 through the second branch channel 112. Both the first explosion-proof cavity 12 and the second explosion-proof cavity 13 can isolate the flame, thereby improving the explosion-proof performance of the valve positioner of this application.

[0046] It is understood that the electrical conversion assembly 4 is not limited to being disposed within the main cavity 14. Exemplarily, the electrical conversion assembly 4 may also be disposed within the first explosion-proof cavity 12.

[0047] In one embodiment, please refer to FIG4, the housing 1 has a wire hole 15, and the main cavity 14 is connected to the first explosion-proof cavity 12 through the wire hole 15, so that the signal line of the feedback component 5 can be connected to the electrical conversion component 4 through the wire hole 15, so that the electrical conversion component 4 can output the corresponding air pressure signal according to the position of the valve core of the slide valve 7 fed back by the feedback component 5. For example, the diameter of the through hole 15 can range from 6mm to 12mm, which is larger than the diameter of the signal line of the feedback component 5. This allows the main cavity 14 and the first explosion-proof cavity 12 to be considered as a whole. Consequently, when an explosion occurs inside the outer casing 1, the main cavity 14 and the first explosion-proof cavity 12, which can be considered as a whole, can reduce the destructive force of high-pressure gas and flames oscillating back and forth between the main cavity 14 and the first explosion-proof cavity 12 through the through hole 15. This reduces the possibility of flammable and explosive gases outside the valve positioner exploding, and also reduces the possibility of the signal line of the feedback component 5 inside the through hole 15 being damaged by the back-and-forth oscillation impact. This further reduces the possibility of the valve positioner malfunctioning, thereby minimizing the impact on subsequent maintenance and hazard investigation of the valve positioner.

[0048] For example, the diameter of the wire hole 15 can be 6mm, 7mm, 8mm, 9mm, 10mm, 11mm or 12mm.

[0049] It is understood that the diameter of the wire hole 15 is not limited to 6mm to 12mm. For example, the diameter of the wire hole 15 can be less than 6mm or greater than 12mm.

[0050] In one embodiment, referring to Figure 4, the outer casing 1 has a wire passage hole 15. The main cavity 14 is connected to the first explosion-proof cavity 12 through the wire passage hole 15, so that the signal line of the feedback component 5 can be connected to the electrical conversion component 4 through the wire passage hole 15. The valve positioner also includes a sealing element, which is disposed in the wire passage hole 15 to close the wire passage hole 15. The signal line of the feedback component 5 passes through the sealing element. That is, the sealing element can not only close the wire passage hole 15, but also allow the signal line of the feedback component 5 to pass through, so that the main cavity 14 and the first explosion-proof cavity 12 are independent of each other, so that the flame generated inside the valve positioner can be blocked by the sealing element. That is, the flame in the main cavity 14 cannot propagate to the first explosion-proof cavity 12 through the wire passage hole 15, and the flame in the first explosion-proof cavity 12 cannot propagate to the main cavity 14 through the wire passage hole 15, which is beneficial to improving the explosion-proof effect of the valve positioner.

[0051] In one embodiment, please refer to Figures 5 and 7. The outer casing 1 has a through hole 16 communicating with the outside. The through hole 16 can be a sensor air passage as shown in Figure 5, or a breathing hole as shown in Figure 7. The valve positioner also includes a sintered filter element 3, which is disposed in the through hole 16 to reduce the possibility of flame inside the valve positioner spreading to the outside, thereby improving the explosion-proof performance of the valve positioner.

[0052] In one embodiment, referring to Figure 6, the valve positioner includes a feedback shaft assembly 6. The feedback shaft assembly 6 provides feedback on the actual opening degree of the valve. The feedback shaft assembly 6 is connected to the housing 1 via an explosion-proof thread. For example, it can be a standard explosion-proof thread connection. The specifications of the explosion-proof thread can be: a nominal diameter of 27 mm, a pitch of 2 mm, and 10 turns. The explosion-proof thread connection between the feedback shaft assembly 6 and the housing 1 reduces the possibility of flames inside the valve positioner propagating to the outside through the assembly gap between the feedback shaft assembly 6 and the housing 1, thus improving the explosion-proof performance of the valve positioner.

[0053] In one embodiment, referring to Figures 3 to 5, the outer casing 1 includes a base 18 and a top cover 17 connected to each other. The top cover 17 encloses the main cavity 14, and the base 18 encloses the pneumatic channel 11, the first explosion-proof cavity 12, and the second explosion-proof cavity 13. The top cover 17 includes an explosion-proof glass 171 and a cover body 172. The cover body 172 is connected to the base 18. The explosion-proof glass 171 is disposed on the side of the cover body 172 away from the base 18. On the one hand, the explosion-proof glass 171 helps to improve the explosion-proof performance of the valve positioner. On the other hand, the user can intuitively observe the internal condition of the valve positioner through the explosion-proof glass 171, which facilitates the inspection and maintenance of the valve positioner.

[0054] For example, referring to Figure 3, the housing 1 may also include a first end cap 19 and a second end cap 20. The base 18 and the first end cap 19 form a first explosion-proof cavity 12, and the base 18 and the second end cap 20 form a second explosion-proof cavity 13. The base 18 and the first end cap 19 and the base 18 and the second end cap 20 may both be provided with long mating surfaces to improve the sealing between the base 18 and the first end cap 19 and between the base 18 and the second end cap 20.

[0055] For example, the length of the mating surface between the first end cap 19 and the base 18 can be 23.6 mm, and the length of the mating surface between the second end cap 20 and the base 18 can be 24.5 mm, so as to improve the sealing performance between the first end cap 19 and the second end cap 20 and the base 18 respectively.

[0056] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A valve positioner, characterized by, The device includes an outer casing, within which are provided a pneumatic channel, a first explosion-proof chamber, and a second explosion-proof chamber. The pneumatic channel includes a first branch channel and a second branch channel. The first branch channel communicates with the first explosion-proof chamber, and the second branch channel communicates with the second explosion-proof chamber. When a flame is generated inside the outer casing, the flame can move towards the first explosion-proof chamber through the first branch channel, and the flame can move towards the second explosion-proof chamber through the second branch channel.

2. The valve positioner of claim 1, wherein The pneumatic channel includes a flow divider cavity. The first branch channel and the second branch channel are both connected to the flow divider cavity. The first explosion-proof cavity and the second explosion-proof cavity are located on both sides of the outer shell along the radial direction of the outer shell. The first explosion-proof cavity and the flow divider cavity are located on the same side of the outer shell along the radial direction of the outer shell.

3. The valve positioner of claim 1, wherein, The valve positioner includes a throttling device disposed within the second branch channel. The throttling device includes a throttling seat and a jewel, the jewel being disposed within the throttling seat and having a throttling orifice configured to penetrate the jewel along the gas flow direction within the second branch channel.

4. The valve positioner of claim 3, wherein, The valve positioner also includes a sintered filter element, which is disposed within the throttling seat.

5. Valve positioner according to any of claims 1-4, characterized in that The valve positioner includes an electrical conversion component and a feedback component. The housing also has a main cavity that is independent of the first explosion-proof cavity. The electrical conversion component is disposed in the main cavity, and the feedback component is disposed in the first explosion-proof cavity.

6. The valve positioner of claim 5, wherein, The housing has a wire passage hole, and the main cavity is connected to the first explosion-proof cavity through the wire passage hole, so that the signal line of the feedback component can be connected to the electrical conversion component through the wire passage hole.

7. The valve positioner of claim 5 wherein, The housing has a wire passage hole, and the main cavity is connected to the first explosion-proof cavity through the wire passage hole, so that the signal line of the feedback component can be connected to the electrical conversion component through the wire passage hole. The valve positioner also includes a sealing element, which is disposed in the wire passage hole to close the wire passage hole, and the signal line of the feedback component passes through the sealing element.

8. The valve positioner according to any one of claims 1 to 3, characterized in that The outer casing has a through hole communicating with the outside, and the valve positioner also includes a sintered filter element disposed within the through hole.

9. The valve positioner according to any one of claims 1 to 4, characterized in that The valve positioner includes a feedback shaft assembly, which is threadedly connected to the explosion-proof housing.

10. The valve positioner according to any one of claims 1 to 4, characterized in that, The outer casing includes a base and a top cover that are connected to each other. The top cover encloses the main cavity, and the base encloses the pneumatic channel, the first explosion-proof cavity, and the second explosion-proof cavity. The top cover includes explosion-proof glass and a cover body. The cover body is connected to the base, and the explosion-proof glass is disposed on the side of the cover body away from the base.

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