Check valve with backflow prevention function and backflow prevention method thereof

Abstract

The invention discloses an anti-backflow check valve and an anti-backflow method thereof, and belongs to the technical field of check valves. Comprising a valve body, a first opening and closing assembly is installed at the liquid inlet end of the valve body, a flow guide assembly is installed in the valve body, the flow guide assembly is locally connected with the inner wall of the valve body, and the first opening and closing assembly is locally and operatively inserted into the flow guide assembly; the opening and closing directions of the second opening and closing assembly and the first opening and closing assembly are consistent, so that directional fluid flows through the valve body, and the fluid is prevented from flowing in the direction under the cooperation of the first opening and closing assembly and the second opening and closing assembly. Fluid flows into the valve body through the gap of the rotating valve clack, impact is formed on the first opening and closing assembly, the first opening and closing assembly is rapidly closed, and therefore the dead time of the fluid in a pipeline is shortened, the response speed of a system is increased, the dead time of the fluid in the pipeline is shortened, directional flowing of the fluid is achieved, and backflow of the fluid is prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of check valves, and in particular relates to a check valve with backflow prevention function and a backflow prevention method thereof. Background Art

[0002] An automatic check valve is a valve used to prevent the reverse flow of fluid in a piping system. It usually relies on the pressure and flow rate of the fluid to open and close automatically without external operation.

[0003] The existing spring-type automatic check valve uses the rebound of the spring to block the backflow of the fluid. However, the spring of this automatic check valve is prone to failure during long-term use. When the spring fails, the valve disc cannot close when the fluid flows back, resulting in the system being unable to prevent the reverse flow of the fluid. Summary of the invention

[0004] Purpose of the invention: To provide a check valve with backflow prevention function and a backflow prevention method thereof, so as to solve the above-mentioned problems existing in the prior art.

[0005] Technical solution: A check valve with backflow prevention function, comprising a valve body, a first opening and closing component installed at the liquid inlet end of the valve body, a flow guide component installed in the valve body, the flow guide component is partially connected to the inner wall of the valve body, the first opening and closing component is partially operatively inserted into the flow guide component, and a second opening and closing component is installed at the liquid outlet end of the valve body, the second opening and closing component has the same opening and closing direction as the first opening and closing component, so that a directional fluid flows through the valve body, and with the cooperation of the first opening and closing component and the second opening and closing component, the directional flow of the fluid is prevented.

[0006] Preferably, the valve body includes a liquid inlet pipe, the first opening and closing component is installed at the liquid outlet of the liquid inlet pipe, the liquid outlet of the liquid inlet pipe is installed with a spherical pipe, the guide component is arranged in the spherical pipe, the spherical pipe is installed and connected with a liquid outlet pipe at a position opposite to the liquid inlet pipe, the liquid inlet pipe, the spherical pipe and the liquid outlet pipe form a "Z"-shaped accommodating cavity, the liquid outlet of the liquid outlet pipe is installed with a second opening and closing component, and with the cooperation of the first opening and closing component, the guide component and the second opening and closing component, the fluid flows through the "Z"-shaped accommodating cavity in a direction.

[0007] Preferably, the guide assembly includes a guide ring, which is funnel-shaped, wherein the end of the guide ring with a smaller diameter is close to the first opening and closing assembly, and the end of the guide ring with a larger diameter is close to the second opening and closing assembly, and the end of the guide ring with a smaller diameter is sleeved on the end of the first opening and closing assembly. A plurality of support rods are provided on the outside of the guide ring, and the support rods are arranged on the outer wall of the guide ring along a circumferential array, and the other end of the support rod is connected to the inner wall of the valve body, and a round bullet-shaped accommodating cavity is formed in the guide ring from the large diameter end of the guide ring to the small diameter end.

[0008] Preferably, the first opening and closing component includes a movable valve flap, the interior of the valve body close to the movable valve flap is provided with an annular sealing protrusion, one end face of the movable valve flap is provided with an annular groove, the annular groove is operatively sleeved with the annular sealing protrusion, the other end face of the movable valve flap is provided with a movable rod, the center axis of the movable rod overlaps with the center axis of the movable valve flap, the movable rod is inserted into the small diameter end of the guide ring, a reset spring is sleeved on the movable rod, one end of the reset spring is connected to the guide ring, and the other end of the reset spring is connected to the movable valve flap.

[0009] Preferably, the second opening and closing component includes a fixed block, which is installed at the edge of the liquid outlet end of the valve body, a rotating shaft is installed at one end of the fixed block, the central axis of the rotating shaft is perpendicular to the central axis of the valve body, a swing arm is rotatably sleeved on the rotating shaft, a mounting column is sleeved on the other end of the swing arm, a rotating valve flap is installed at the end of the mounting column, and the central axis of the rotating valve flap overlaps with the central axis of the mounting column.

[0010] Preferably, the second opening and closing component also includes an external pipe, which is sleeved on the liquid outlet end of the valve body, and an inclined pipe is installed on one side of the sleeve pipe, and the angle between the inclined pipe and the external pipe is toward the rotating valve disc, and the end of the inclined pipe away from the external pipe is connected to an arc pipe, and the arc pipe is connected to the external pipe, and the outlet end of the arc pipe is toward the end of the external pipe away from the rotating valve disc.

[0011] A method for preventing backflow of a check valve, wherein the check valve with backflow prevention function described above is used to prevent backflow of a fluid, comprising the following steps:

[0012] S1. After the check valve is installed on the delivery pipe, the fluid flows to the first opening and closing component through the delivery pipe. Under the impact of the fluid, the first opening and closing component is opened, and the fluid flows smoothly into the guide component. Under the guidance of the guide component, the fluid quickly flows to the second opening and closing component, flushing the second opening and closing component open. The fluid flows smoothly into the second opening and closing component and then flows into the delivery pipe;

[0013] S2. When the fluid delivery to the fluid stops, the fluid in the delivery pipe quickly flows back, causing the second opening and closing component to close quickly. During the closing process, part of the fluid flows back into the guide component. Under the action of the guide ring in the guide component, the reverse-flowing fluid generates thrust, which cooperates with the reset spring to quickly close the first opening and closing component to prevent the fluid from flowing in the opposite direction.

[0014] Preferably, after the fluid in step 1 flushes the first opening and closing component, in order to make the fluid flow quickly through the check valve and increase the impulse of the fluid, the inlet end of the valve body adopts the flow channel line equation to design the inlet section line of the valve body, wherein the flow channel line equation is as follows:

[0015]

[0016] Wherein: r1 represents the radius of the flow channel at the corresponding end of the first opening and closing component, r2 represents the radius of the outlet end of the conveying pipe, and r3 represents the maximum radius of the guide ring.

[0017] Preferably, after the fluid flows back into the guide assembly in step 2, in order to quickly close the first opening and closing assembly, the guide ring is divided into a front section and a rear section with the maximum diameter of the guide ring as a dividing line, wherein the radius of the front section of the guide ring is calculated by formula (1), and formula (1) is as follows:

[0018]

[0019] Where: d represents the maximum radius of the guide ring; a represents the length of the front section of the guide ring; x1 represents the distance from the reference point to the front end of the guide ring, n f Indicates the profile adjustment parameters of the front arc of the guide ring.

[0020] Preferably, the arc length of the rear section of the guide ring is calculated by formula (2): Formula (2) is as follows:

[0021]

[0022] Where: c represents the length of the rear section of the guide ring; x2 represents the distance from the reference point to the rear end of the guide ring, n a Indicates the profile adjustment parameters of the rear arc of the guide ring.

[0023] Beneficial effects: The present invention relates to a check valve with backflow prevention and a backflow prevention method thereof, wherein the first opening and closing component and the second opening and closing component are automatically opened under the impact of the fluid, and the fluid can flow smoothly through the check valve, and after the fluid stops flowing, the fluid at the end of the second opening and closing component flows back to impact the rotating valve flap of the second opening and closing component, and at the same time, in conjunction with the fluid flowing into the inclined pipe, the fluid forms a directional flow in the external pipe, increasing the directional impact on the rotating valve flap, so that the rotating valve flap is quickly closed;

[0024] Secondly, during the process of rotating the valve disc to close the flow direction, the fluid flows into the valve body through the gap of the rotating valve disc. Under the action of the guide ring, the fluid flows into the guide ring in a concentrated manner, impacting the first opening and closing component, causing the first opening and closing component to close quickly, thereby reducing the stagnation time of the fluid in the pipeline, improving the response speed of the system, thereby reducing the stagnation time of the fluid in the pipeline, and realizing directional flow of the fluid. Even when the fluid stops flowing, with the cooperation of the first opening and closing component and the second opening and closing component, the fluid is prevented from flowing back, ensuring the directional flow of the fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 It is a closed cross-sectional view of the first opening and closing assembly of the present invention;

[0027] Figure 3 This is a cross-sectional view of the first opening and closing component of the present invention;

[0028] Figure 4 for Figure 3 Enlarged view of point A.

[0029] Figures 1 to 4 The reference numerals in the drawings are: 1, valve body; 2, first opening and closing component; 3, flow guide component; 4, second opening and closing component;

[0030] 101, liquid inlet pipe; 102, spherical pipe; 103, liquid outlet pipe; 104, Chinese-shaped receiving chamber;

[0031] 201, movable valve disc; 202, annular sealing protrusion; 203, annular groove; 204, movable rod; 205, return spring;

[0032] 301, guide ring; 302, support rod;

[0033] 401, fixed block; 402, rotating shaft; 403, swing arm; 404, mounting column; 405, rotating valve disc; 406, external pipeline; 407, inclined pipeline; 408, arc pipeline. DETAILED DESCRIPTION

[0034] like Figures 1 to 4As shown, the present invention provides a technical solution: a check valve with backflow prevention, comprising a valve body 1, a first opening and closing component 2 and a second opening and closing component 4, the first opening and closing component 2 being installed at the liquid inlet end of the valve body 1, the second opening and closing component 4 being installed at the liquid outlet end of the valve body 1, a flow guide component 3 being installed in the valve body 1, the flow guide component 3 being partially connected to the inner wall of the valve body 1, the first opening and closing component 2 being partially operatively inserted into the flow guide component 3, the second opening and closing component 4 being consistent in opening and closing direction with the first opening and closing component 2, the first opening and closing component 2 and the second opening and closing component 4 being automatically opened under the impact of the fluid, the fluid being able to flow smoothly through the check valve, and after the fluid stops flowing, the fluid at the end of the second opening and closing component 4 is refluxed, which impacts the rotating valve disc 4 of the second opening and closing component 4 05 impact, and at the same time, cooperate with the fluid flowing into the inclined pipe 407 to form a directional flow of the fluid in the external pipe 406, increase the directional impact on the rotating valve disc 405, and make the rotating valve disc 405 close quickly. Secondly, in the process of the rotating valve disc 405 flowing to the closing direction, the fluid flows into the valve body 1 through the gap of the rotating valve disc 405. Under the action of the guide ring 301, the fluid is concentrated and flows into the guide ring 301, forming an impact on the first opening and closing component 2, so that the first opening and closing component 2 is quickly closed, thereby reducing the stagnation time of the fluid in the pipeline, improving the response speed of the system, thereby reducing the stagnation time of the fluid in the pipeline, and realizing the directional flow of the fluid. Even when the fluid stops flowing, under the cooperation of the first opening and closing component 2 and the second opening and closing component 4, the fluid is prevented from flowing back, ensuring the directional flow of the fluid

[0035] In a further embodiment, the valve body 1 includes a liquid inlet pipe 101, the first opening and closing component 2 is installed at the liquid outlet of the liquid inlet pipe 101, the liquid outlet of the liquid inlet pipe 101 is installed with a spherical pipe 102, the guide component 3 is arranged in the spherical pipe 102, the guide component 3 includes a guide ring 301, the guide ring 301 is funnel-shaped, and the guide ring 301 is arranged in the spherical pipe 102, wherein the end with a small diameter of the guide ring 301 is close to the first opening and closing component 2, the end with a large diameter of the guide ring 301 is close to the second opening and closing component 4, the end with a small diameter of the guide ring 301 is sleeved on the end of the first opening and closing component 2, and the guide ring 30 1 is provided with a plurality of support rods 302 on the outside, the support rods 302 are arranged in a circumferential array on the outer wall of the guide ring 301, the other end of the support rods 302 is connected to the inner wall of the valve body 1, and a round bullet-shaped accommodation cavity is formed in the guide ring 301 from the large diameter end of the guide ring 301 to the small diameter end, and a liquid outlet pipe 103 is installed and connected at the opposite position of the spherical pipe 102 and the liquid inlet pipe 101, and the liquid inlet pipe 101, the spherical pipe 102 and the liquid outlet pipe 103 form a Chinese-character accommodating cavity 104, and a second opening and closing component 4 is installed at the liquid outlet of the liquid outlet pipe 103. Under the cooperation of the first opening and closing component 2, the guide component 3 and the second opening and closing component 4, the fluid flows through the Chinese-character accommodating cavity 104 in a direction.

[0036] In a further embodiment, the first opening and closing component 2 includes a movable valve flap 201, an annular sealing protrusion 202, an annular groove 203, a movable rod 204 and a reset spring 205. The valve body is provided with an annular sealing protrusion 202 inside the movable valve flap 201. An annular groove 203 is provided on one end surface of the movable valve flap 201. The annular groove 203 is operatively sleeved with the annular sealing protrusion 202. A movable rod 204 is installed on the other end surface of the movable valve flap 201. The central axis of the movable rod 204 overlaps with the central axis of the movable valve flap 201. The movable rod 204 is inserted into the movable valve flap 201. At the small diameter end of the guide ring 301, a reset spring 205 is sleeved on the moving rod 204, one end of the reset spring 205 is connected to the guide ring 301, and the other end of the reset spring 205 is connected to the moving valve flap 201. With the cooperation of the reset spring 205 and the guide component 3, the annular groove 203 of the moving valve flap 201 is sleeved on the annular sealing protrusion 202 to form a seal, and when the reset spring 205 fails, with the cooperation of the guide ring 301, the reflux fluid impacts the moving rod 204, so that the moving valve flap 201 can be moved, and the first opening and closing component 2 is closed.

[0037] In a further embodiment, the second opening and closing component 4 includes a fixed block 401, which is installed at the edge of the liquid outlet end of the valve body 1, a rotating shaft 402 is installed at one end of the fixed block 401, and the central axis of the rotating shaft 402 is perpendicular to the central axis of the valve body 1, a swing arm 403 is rotatably sleeved on the rotating shaft 402, and a mounting column 404 is sleeved on the other end of the swing arm 403, and a rotating valve flap 405 is installed at the end of the mounting column 404, and the central axis of the rotating valve flap 405 overlaps with the central axis of the mounting column 404, and the liquid outlet end of the valve body 1 is sleeved with an external pipe 406, An inclined pipe 407 is installed on one side of the sleeve pipe, and the angle between the inclined pipe 407 and the external pipe 406 is toward the rotating valve disc 405. The end of the inclined pipe 407 away from the external pipe 406 is connected with an arc pipe 408, and the arc pipe 408 is connected to the external pipe 406. The outlet end of the arc pipe 408 faces the end of the external pipe 406 away from the rotating valve disc 405. When the fluid stops flowing, the fluid in the external sleeve flows back. During the backflow process, part of the fluid flows into the inclined pipe 407, and under the action of the arc pipe 408, a fluid flows toward the liquid outlet end of the external sleeve, such as Figure 3 As shown, under the action of the fluid flowing back from the external sleeve, an S-shaped fluid flow is formed, which forms an impact force on the end of the rotating valve flap 405 close to the rotating shaft 402, so that the rotating valve flap 405 is quickly closed.

[0038] A method for preventing backflow of a check valve comprises the following steps:

[0039] Step 1: After the check valve is installed on the delivery pipe, the fluid flows through the delivery pipe to the first opening and closing component 2. Under the impact of the fluid, the first opening and closing component 2 is opened. When the fluid rushes through the first opening and closing component 2, in order to make the fluid flow through the check valve quickly and increase the impulse of the fluid, the inlet end of the valve body 1 adopts the flow channel line equation to design the inlet section line of the valve body 1. The flow channel line equation is as follows:

[0040]

[0041] In the formula: r1 represents the radius of the flow channel at the corresponding end of the first opening and closing component 2, r2 represents the radius of the outlet end of the delivery pipe, and r3 represents the maximum radius of the guide ring 301. The fluid flows smoothly into the guide component 3, and under the guidance of the guide component 3, it quickly flows to the second opening and closing component 4, flushes the second opening and closing component 4, and the fluid flows smoothly into the second opening and closing component 4 and then flows into the delivery pipe;

[0042] Step 2: When the fluid delivery to the fluid stops, the fluid in the delivery pipe quickly flows back. After the fluid flows back into the guide assembly 3, in order to quickly close the first opening and closing assembly 2, the guide ring 301 is divided into a front section and a rear section with the maximum diameter of the guide ring 301 as the dividing line, wherein the radius of the front section of the guide ring 301 is calculated by formula (1), and the formula (1) is as follows:

[0043]

[0044] Where: d represents the maximum radius of the guide ring 301; a represents the length of the front section of the guide ring 301; x1 represents the distance from the reference point to the front end of the guide ring 301, n f represents the profile adjustment parameter of the front arc of the guide ring 301. The arc length of the rear arc of the guide ring 301 is calculated by formula (2): Formula (2) is as follows:

[0045]

[0046] Where: c represents the length of the rear section of the guide ring 301; x2 represents the distance from the reference point to the rear end of the guide ring 301, n a The profile adjustment parameters of the rear arc of the guide ring 301 are represented. By calculating the arc lengths of the front and rear ends of the guide ring 301, a design is designed to concentrate the return fluid in the guide ring 301, impact the moving rod 204 in the second opening and closing component 4, drive the moving valve disc 201 to move quickly, and close the second opening and closing component 4 quickly. In the closing process, part of the fluid flows back into the guide component 3. Under the action of the guide ring 301 when the fluid flows into the guide component 3, the reverse-flowing fluid generates thrust, and cooperates with the reset spring 205 to quickly close the first opening and closing component 2 to avoid reverse flow of the fluid.

[0047] The preferred embodiments of the present invention are described in detail above; however, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all belong to the protection scope of the present invention.

Claims

1. A check valve with backflow prevention function, characterized in that: The invention comprises a valve body (1), a first opening and closing component (2) being installed at the liquid inlet end of the valve body (1), a flow guide component (3) being installed inside the valve body (1), the flow guide component (3) being partially connected to the inner wall of the valve body (1), the first opening and closing component (2) being partially operatively inserted into the flow guide component (3), a second opening and closing component (4) being installed at the liquid outlet end of the valve body (1), the second opening and closing component (4) having the same opening and closing direction as the first opening and closing component (2), so that a directional fluid flows through the valve body (1), and the directional flow of the fluid is prevented under the cooperation of the first opening and closing component (2) and the second opening and closing component (4).

2. A check valve with backflow prevention function according to claim 1, characterized in that: The valve body (1) comprises a liquid inlet pipe (101), the first opening and closing component (2) is installed at the liquid outlet of the liquid inlet pipe (101), the liquid outlet of the liquid inlet pipe (101) is installed with a spherical pipe (102), the flow guide component (3) is arranged in the spherical pipe (102), the spherical pipe (102) is installed and connected with a liquid outlet pipe (103) at a position opposite to the liquid inlet pipe (101), the liquid inlet pipe (101), the spherical pipe (102) and the liquid outlet pipe (103) form a Chinese-character shaped accommodation cavity (104), the liquid outlet of the liquid outlet pipe (103) is installed with a second opening and closing component (4), and under the cooperation of the first opening and closing component (2), the flow guide component (3) and the second opening and closing component (4), the fluid flows through the Chinese-character shaped accommodation cavity (104) in a direction.

3. A check valve with backflow prevention function according to claim 1, characterized in that: The guide assembly (3) comprises a guide ring (301), and the guide ring (301) is funnel-shaped, wherein the end of the guide ring (301) with a smaller diameter is close to the first opening and closing assembly (2), and the end of the guide ring (301) with a larger diameter is close to the second opening and closing assembly (4). The end of the guide ring (301) with a smaller diameter is sleeved on the end of the first opening and closing assembly (2). A plurality of support rods (302) are arranged on the outside of the guide ring (301), and the support rods (302) are arranged on the outer wall of the guide ring (301) in an array along the circumferential direction. The other end of the support rod (302) is connected to the inner wall of the valve body (1), and a round bullet-shaped accommodating cavity is formed in the guide ring (301) from the end with a larger diameter to the end with a smaller diameter.

4. A check valve with backflow prevention function according to claim 3, characterized in that: The first opening and closing component (2) comprises a movable valve flap (201); an annular sealing protrusion (202) is provided inside the valve body close to the movable valve flap (201); an annular groove (203) is provided on one end face of the movable valve flap (201); the annular groove (203) is operatively sleeved with the annular sealing protrusion (202); a movable rod (204) is provided on the other end face of the movable valve flap (201); the central axis of the movable rod (204) overlaps with the central axis of the movable valve flap (201); the movable rod (204) is inserted into the small diameter end of the guide ring (301); a reset spring (205) is sleeved on the movable rod (204); one end of the reset spring (205) is connected to the guide ring (301); and the other end of the reset spring (205) is connected to the movable valve flap (201).

5. A check valve with backflow prevention function according to claim 1, characterized in that: The second opening and closing component (4) comprises a fixed block (401), wherein the fixed block (401) is installed at the edge of the liquid outlet end of the valve body (1), a rotating shaft (402) is installed at one end of the fixed block (401), the central axis of the rotating shaft (402) is perpendicular to the central axis of the valve body (1), a swing arm (403) is rotatably sleeved on the rotating shaft (402), and a mounting column (404) is sleeved on the other end of the swing arm (403), and a rotating valve flap (405) is installed at the end of the mounting column (404), and the central axis of the rotating valve flap (405) overlaps with the central axis of the mounting column (404).

6. A check valve with backflow prevention function according to claim 5, characterized in that: The second opening and closing component (4) further comprises an external pipe (406), the external pipe (406) being sleeved on the liquid outlet end of the valve body (1), an inclined pipe (407) being installed on one side of the sleeved pipe, the angle between the inclined pipe (407) and the external pipe (406) being directed toward the rotating valve flap (405), an end of the inclined pipe (407) away from the external pipe (406) being connected to an arc-shaped pipe (408), the arc-shaped pipe (408) being connected to the external pipe (406), the outlet end of the arc-shaped pipe (408) being directed toward the end of the external pipe (406) away from the rotating valve flap (405).

7. A method for preventing backflow of a check valve, wherein the backflow of a fluid is prevented by using the check valve with backflow prevention function as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1. After the check valve is installed on the delivery pipe, the fluid flows to the first opening and closing component (2) through the delivery pipe. Under the impact of the fluid, the first opening and closing component (2) is opened, and the fluid smoothly flows into the flow guide component (3). Under the guidance of the flow guide component (3), the fluid quickly flows to the second opening and closing component (4), flushes the second opening and closing component (4), and the fluid smoothly flows into the second opening and closing component (4) and then flows into the delivery pipe; S2. When the fluid delivery to the fluid stops, the fluid in the delivery pipe quickly flows back, causing the second opening and closing component (4) to close quickly. During the closing process, part of the fluid flows back into the guide component (3). Under the action of the guide ring (301) in the fluid flow guide component (3), the reverse-flowing fluid generates thrust, which cooperates with the reset spring (205) to quickly close the first opening and closing component (2) to prevent the fluid from flowing in the opposite direction.

8. A method for preventing backflow of a check valve according to claim 7, characterized in that: After the fluid in step 1 opens the first opening and closing component (2), in order to make the fluid flow quickly through the check valve and increase the impulse of the fluid, the inlet end of the valve body (1) is designed with a flow channel line equation for the inlet section of the valve body (1), wherein the flow channel line equation is as follows: In the formula: r1 represents the radius of the flow channel at the corresponding end of the first opening and closing component (2), r2 represents the radius of the outlet end of the delivery pipe, and r3 represents the maximum radius of the guide ring (301).

9. A method for preventing backflow of a check valve according to claim 7, characterized in that: After the fluid flows back into the guide assembly (3) in step 2, in order to quickly close the first opening and closing assembly (2), the guide ring (301) is divided into a front section and a rear section with the guide ring (301) having the maximum diameter as a dividing line, wherein the radius of the front section of the guide ring (301) is calculated by formula (1), and formula (1) is as follows: Wherein: d represents the maximum radius of the guide ring (301); a represents the length of the front section of the guide ring (301); x1 represents the distance from the reference point to the front end of the guide ring (301); n f Indicates the profile adjustment parameters of the front arc of the guide ring (301).

10. A method for preventing backflow of a check valve according to claim 9, characterized in that: in, The arc length of the rear section of the guide ring (301) is calculated by formula (2): Formula (2) is as follows: Wherein: c represents the length of the rear section of the guide ring (301); x2 represents the distance from the reference point to the rear end of the guide ring (301); n a Indicates the profile adjustment parameters of the rear arc of the guide ring (301).

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