Scouring-resistant and anti-jamming shaft end structure of high-temperature and high-pressure butterfly valve

Abstract

The shaft end structure comprises a butterfly valve body, a valve plate and a valve shaft, the interior of the valve shaft is hollow, an assembly gap is formed between the valve shaft and the valve body, the inner edge of the side, facing the valve plate, of the assembly gap expands outwards to form a diameter-expanding containing area, and the diameter-expanding containing area is provided with a diameter-expanding opening. The backwashing mechanism comprises a medium leading-in opening, a one-way conduction assembly and a flow dividing channel assembly, the one-way conduction assembly is communicated with the inlet side of the flow dividing channel assembly, and after the valve plate rotates, a medium enters from the medium leading-in opening and sequentially penetrates through the one-way conduction assembly and the flow dividing channel assembly; medium liquid flow output by the flow dividing channel assembly flushes a gap between the diameter expanding containing area and the valve shaft. Through the technical means of designing hydraulic pressure in the pipe to achieve backwashing, sediment accumulation on the surface of the valve shaft is effectively reduced, the problem of rotation blockage caused by residue retention in a shaft end structure of an existing butterfly valve is solved, the service life of the end shaft is prolonged, and the rotation smoothness of the end shaft is improved.

Description

Technical Field

[0001] This invention relates to the field of valve technology, specifically to a shaft end structure for a high-temperature, high-pressure butterfly valve that is resistant to erosion and prevents jamming. Background Technology

[0002] A butterfly valve is a rotary valve. The main structure of a butterfly valve consists of a valve shaft, a valve plate, and a drive mechanism that rotates the valve shaft. The core opening and closing component is a circular butterfly plate that rotates around the valve shaft axis. The flow and cut-off of the medium are controlled by the rotation angle of the butterfly plate. When the butterfly valve is working, the drive mechanism needs to be manually driven to rotate the valve shaft, so that the valve plate rotates between 0° and 90°. The shaft end structure of the butterfly valve specifically refers to the area of ​​the valve plate, the valve shaft, and the mounting hole into which the valve shaft is inserted.

[0003] High-temperature and high-pressure media are prone to scaling, crystallization, or carbonization. For example, calcium and magnesium ions dissolved in high-temperature and high-pressure water vapor precipitate as calcium carbonate and magnesium carbonate due to temperature and pressure changes when flowing through pipeline components such as butterfly valves, forming hard scale that adheres to the valve shaft and flow channel. In polyester synthesis processes, the mixed media of ethylene glycol and terephthalic acid under high temperature and pressure are prone to carbonization due to local temperature fluctuations, generating carbide deposits that block the valve shaft clearance. As the deposits flow with the media and pass through the assembly clearance between the end shaft and the valve body, they directly contact the end shaft structure surface in the assembly clearance, causing scratches on the end shaft surface and affecting its smoothness. With prolonged flushing time, the surface defects will worsen. On the other hand, deposits or particles in the media will accumulate in the assembly clearance, resulting in long-term accumulation on the surface, affecting the smoothness of rotation and sealing performance.

[0004] When the above problems occur, from a safety perspective, it can lead to valve failure to start, wear and leakage of the sealing surface. If this problem is not resolved, the staff may forcefully twist the valve and reduce the sealing performance of the butterfly valve body, thereby causing damage to the valve body torsion structure and affecting normal production operations due to reduced sealing performance.

[0005] The existing technology overcomes this problem by using a triple eccentric sealing mechanism. This structure adopts a triple eccentric design of the valve shaft center, valve plate center, and sealing surface center: when the valve is opened or closed, the valve plate first separates from the sealing surface and then rotates, avoiding forced friction between the sealing surface and the valve plate; when closed, the radial sealing force generated by the eccentric structure makes the sealing surface evenly pressed, and even if the sealing surface is slightly worn, the sealing performance can be maintained through the self-compensation of the structure.

[0006] However, this triple eccentric sealing mechanism cannot solve the problem of fluid residue forming in the assembly gap between the valve shaft and the valve body when the valve plate opens and closes. This leads to the accumulation of deposits on the shaft end structure after long-term use, which hinders the rotation of the valve shaft and causes further seal failure. Summary of the Invention

[0007] The purpose of this invention is to provide a shaft end structure for a high-temperature and high-pressure butterfly valve that is resistant to erosion and prevents jamming, so as to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a shaft end structure of a high-temperature and high-pressure butterfly valve that is resistant to erosion and prevents jamming, comprising a butterfly valve body, a valve plate, and a valve shaft, wherein the valve shaft is hollow inside and there is a fitting clearance between the valve shaft and the valve body, characterized in that: an expansion diameter accommodating area is provided between the valve shaft and the valve body; It also includes a backwashing mechanism, which includes a media inlet, a one-way conduction component, and a diversion channel component. The media inlet is located on the valve shaft and communicates with the inside of the valve shaft, and is configured to introduce media from the valve body inlet side. The unidirectional conduction assembly is connected inside the valve shaft and corresponds to the medium inlet. The diversion channel assembly is connected to the unidirectional guiding assembly and is configured to guide the medium guided by the unidirectional guiding assembly to the mating area between the expansion diameter receiving area and the valve shaft to achieve flushing.

[0009] Preferably, the unidirectional conduction assembly includes a limiting ring, a spring, and a piston. The limiting ring is fixed inside the valve shaft, the pointed end of the piston is inserted into the middle of the limiting ring, and the other end of the piston is fixed with a spring. The other end of the spring is fixedly connected to the inner wall of the valve shaft.

[0010] Preferably, the piston surface has through holes arranged in a ring array.

[0011] Preferably, the flow diversion channel assembly includes a hollow region of the valve shaft and flow diversion channels communicating with the hollow region, wherein the flow diversion channels are distributed in a ring array on the surface of the valve shaft.

[0012] Preferably, the lower end diameter of the diversion channel is larger than the upper end diameter.

[0013] Preferably, the sealing mechanism includes a sealing ring and a flow guide key. The sealing ring is sleeved on the outer wall of the valve shaft and placed inside the enlarged diameter receiving area. The flow guide key is distributed in a ring array on the surface of the sealing ring.

[0014] Preferably, the outer walls of the sealing ring are fixed with protrusions on both sides, and the expansion accommodating area is provided with grooves on both sides. The protrusions are adapted to be inserted into the grooves, and one side of the groove is a semi-open design.

[0015] Preferably, the flow guide keys are arranged in a ring array and the surface fluid flow direction is designed to gradually increase linearly.

[0016] Preferably, the outer wall of the valve shaft is fixed with limiting keys arranged in a ring array. The limiting keys are in contact with the flow guiding surface of the outer wall of the flow guiding key, and the maximum longitudinal distance from the upper edge of the flow guiding key to the bottom of the flow guiding surface is less than the travel of the sealing ring.

[0017] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention achieves efficient flushing of areas prone to sediment formation, such as the valve shaft surface and the interior of the expanded diameter containment area, through a dual flushing mode of valve plate opening flushing and valve plate closing high-pressure backflushing. Combined with structural designs such as annular array diversion channels, variable diameter diversion channels, and gradually opening media inlets, it can effectively flush away residual liquid and prevent residue adhesion.

[0018] 2. This invention ensures that the sealing ring can accurately follow the rotation of the valve shaft to perform axial reciprocating motion through the precise insertion and matching of the sealing ring and the groove of the expanded diameter receiving area, and the coordinated transmission of the limiting key and the guide block, so as to achieve a tight seal when the valve plate is closed; at the same time, the one-way sealing design of the one-way conduction structure avoids liquid backflow, further improves the overall sealing performance, and effectively reduces the risk of liquid leakage.

[0019] 3. On the one hand, the invention reduces the corrosion and wear of components such as valve shafts and sealing rings by the efficient backwashing function, thus extending the service life of core components. On the other hand, the device uses pressure difference to drive the backwashing mechanism to open and close, eliminating the need for an additional power source, simplifying the structure and reducing the failure rate. At the same time, the semi-open groove design facilitates the installation and maintenance of components, reducing maintenance difficulty and cost.

[0020] 4. By reducing residue adhesion and corrosion, this invention effectively avoids problems such as valve shaft jamming and uneven rotation caused by corrosion, ensuring the normal opening and closing function of the butterfly valve, improving the overall operational stability of the equipment, and is suitable for long-term use under harsh working conditions such as high pressure and high temperature. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the main structure of the butterfly valve of the present invention; Figure 2 This is a schematic diagram of the structural rotation mechanism of the present invention; Figure 3 This is a schematic diagram showing the location of the expanded diameter accommodating region of the present invention; Figure 4 For the present invention Figure 3 Enlarged schematic diagram of the C-structure; Figure 5 This is a partial cross-sectional view of the structure of the present invention; Figure 6 The structure of the present invention Figure 5 Enlarged schematic diagram of structure A in the middle; Figure 7The structure of the present invention Figure 2 Enlarged schematic diagram of the B-structure; Figure 8 This is a schematic diagram of the sealing ring structure of the present invention; Figure 9 The structure of the present invention Figure 4 Enlarged schematic diagram of the D-structure.

[0022] In the picture: 100. Butterfly valve body; 101. Valve body; 102. Expanded diameter receiving area; 103. Groove; 200. Rotating mechanism; 201. Valve shaft; 202. Valve plate; 203. Mounting hole; 204. Limit key; 205. Medium inlet; 206. Diversion channel assembly; 207. Diversion channel; 300. One-way conduction assembly; 301. Limiting ring; 302. Piston; 303. Spring; 304. Through hole; 400. Sealing mechanism; 401. Sealing ring; 402. Flow guide key; 403. Protrusion. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] Please see Figures 1 to 9 The present invention provides the following two embodiments: Example 1: A shaft end structure of a high-temperature and high-pressure butterfly valve that is resistant to erosion and prevents jamming includes a butterfly valve body 100, a valve plate 202, and a valve shaft 201. The valve plate 202 and the valve shaft 201 are included in a rotating mechanism 200. The valve shaft 201 is inserted into a mounting hole 203 in the middle of the valve body 101. The inside of the valve shaft 201 is hollow, and there is a fitting clearance between the valve shaft 201 and the valve body 101. An enlarged diameter receiving area 102 is provided between the valve shaft 201 and the valve body 101.

[0025] Specifically, the expansion-diameter accommodating area 102 is a groove-shaped structure connected to the mating clearance, and the inner diameter of the groove-shaped structure is larger than the inner diameter of the mating clearance.

[0026] It also includes a backwashing mechanism, which includes a media inlet 205, a one-way flow assembly 300 and a diversion channel assembly 206. The media inlet 205 is opened on the valve shaft 201 and communicates with the inside of the valve shaft 201, and is configured to introduce media from the inlet side of the valve body 101.

[0027] The one-way guide assembly 300 is connected inside the valve shaft 201 and corresponds to the medium inlet 205.

[0028] The diversion channel assembly 206 is connected to the unidirectional guide assembly 300 and is configured to guide the medium guided by the unidirectional guide assembly 300 to the mating area between the expansion diameter receiving area 102 and the valve shaft 201 to achieve flushing.

[0029] The unidirectional guide assembly 300 is connected to the inlet side of the diversion channel assembly 206, and the outlet side of the diversion channel assembly 206 is located in the gap between the expansion diameter receiving area 102 and the valve shaft 201.

[0030] It is worth noting that the rotation of the valve plate 202 reduces the medium flow area inside the valve body 101, and the pressure on the inlet side of the valve body 101 increases. The medium enters through the medium inlet 205 and passes through the unidirectional guide assembly 300 and the diversion channel assembly 206 in sequence. The medium flow output by the diversion channel assembly 206 flushes the gap between the expansion diameter receiving area 102 and the valve shaft 201, flushing out the mud and sand and other impurities in the gap. This keeps the end shaft structure in good working condition and avoids the mud and sand particles trapped in the gap from causing scratches and other defects on the end shaft structure surface due to friction during the rotation of the end shaft structure. If the end shaft structure surface is scratched, under long-term high temperature and high pressure conditions, the surface scratches will damage the surface structure of the end shaft, making it prone to corrosion and affecting the service life of the end shaft structure. Secondly, the mud and sand trapped inside will also have a certain impact on the smooth operation of the end shaft structure. After rinsing, the mud and sand particles in the gaps are completely flushed out, eliminating the risk of mud and sand particles scratching the surface of the end shaft structure. At the same time, no mud and sand particles will remain in the gaps, keeping the end shaft structure in good working condition and naturally having good rotational smoothness.

[0031] The unidirectional guiding assembly 300 includes a limiting ring 301, a spring 303, and a piston 302. The limiting ring 301 is fixed inside the valve shaft 201. The pointed part of the piston 302 is inserted into the middle of the limiting ring 301, and the other end is fixed with the spring 303. The other end of the spring 303 is fixedly connected to the inner wall of the valve shaft 201. When the valve plate 202 is closed, the pressure of the piston 302 caused by the liquid flow increases, eventually pushing open the spring 303 and entering the diversion channel 207 to achieve backflushing.

[0032] It is worth noting that the one-way flow assembly 300 is not limited to the assembly consisting of the limiting ring 301, spring 303, and piston 302 described above. Those skilled in the art can also directly replace the one-way flow assembly 300 with a check valve from the prior art, and the implementation can proceed accordingly. For example, a check valve of model H21X-320P. The check valve can be welded to the hollow area of ​​the valve shaft 201. After the fluid passes through the check valve from the medium inlet 205, it enters the diversion channel 207.

[0033] The piston 302 has through holes 304 arranged in a ring array on its surface. After the pressurized medium enters the hollow area of ​​the valve shaft 201 from the medium inlet 205 and pushes the piston 302 open, the liquid will flow from the hollow area of ​​the valve shaft 201 to the diversion channel 207 through the through holes 304 and finally spray out to achieve backwashing.

[0034] The diversion channel assembly 206 includes a hollow region of valve shaft 201 and a diversion channel 207 communicating with the hollow region. The diversion channel 207 is distributed in a ring array on the surface of valve shaft 201. As the pressure increases during the closing of valve plate 202, the liquid pushes open piston 302, and the liquid flows along the hollow region of valve shaft 201 to the diversion channel 207.

[0035] When the valve shaft 201 drives the valve plate 202 to rotate, the rotation of the valve plate 202 reduces the flow cross-section inside the valve body 101. Due to the smaller cross-section, the pressure of the medium at the inlet side of the valve body 101 increases. After the valve shaft 201 rotates, the medium inlet 205 synchronously turns to the medium input direction. The pressurized medium can directly enter the hollow valve shaft 201 through the medium inlet 205, and then contact the end face of the piston 302. The pressurized medium pushes the piston 302 to move after overcoming the elastic force of the spring 303, causing the piston 302 to disengage from the limit ring 301. When the medium passes through the piston 302, it flows from the hollow area of ​​the valve shaft 201 to the diversion channel 207 through the through hole 304, and is finally ejected from the output port of the diversion channel 207. This achieves the effect of flushing the mud and sand particles retained in the expanded diameter receiving area 102. After flushing, the mud and sand particles in the gap are completely flushed out, completely eliminating the risk of mud and sand particles scratching the surface of the end shaft structure. At the same time, no mud and sand particles are retained in the gap, keeping the end shaft structure in good working condition and naturally having good rotational smoothness.

[0036] It is worth noting that the flow cross section in the diversion channel 207 located at the upper end of the valve body 101 is smaller than that in the diversion channel 207 located at the lower end of the valve shaft 201. The lower end diameter of the diversion channel 207 is larger than the upper end diameter. Since the sediment inside the pipe is mainly concentrated in the lower end expansion area 102, the diameter of the lower diversion channel 207 of the valve shaft 201 is designed to be larger than the upper diameter. This allows the backwash flow rate at the lower end to be greater than that at the upper end, achieving a targeted backwash effect.

[0037] When valve shaft 201 rotates from 0° to 90°, that is, during the process of valve plate 202 changing from fully open to fully closed, liquid flow enters from medium inlet 205, immediately pushing piston 302 open against the spring force of spring 303. High-pressure, high-temperature liquid flows through medium inlet 205 and through through hole 304 into diversion channel 207, and then sprays out from the outlet of diversion channel 207 into the internal region of expansion diameter receiving area 102, accelerating the liquid flow inside expansion diameter receiving area 102 and depositing liquid in expansion diameter receiving area 102. The silt particles inside are flushed out of the area, reducing the intrusion of stubborn deposits into the area and their adhesion to the surface of the valve shaft 201. This would cause scratches and damage to the surface of the valve shaft 201 during repeated rotation, thus hindering the rotation of the valve shaft 201 and affecting its service life. After flushing, the silt particles in the gaps are completely flushed out, completely eliminating the risk of silt particles scratching the surface of the end shaft structure. At the same time, no silt particles will remain in the gaps, keeping the end shaft structure in good working condition and naturally having good rotational smoothness.

[0038] Example 2: Based on the above technical solution, another embodiment is proposed: It also includes a sealing mechanism 400, which includes a sealing ring 401, a flow guide key 402, and a protrusion 403. The sealing ring 401 is sleeved on the outer wall of the valve shaft 201 and placed inside the expansion diameter receiving area 102. The inner wall of the expansion diameter receiving area 102 has a groove 103. The protrusion 403 is inserted into the groove 103 to ensure that the sealing ring 401 will not rotate. The flow guide key 402 is distributed in a ring array on the surface of the sealing ring 401. The streamlined design of the flow guide surface allows the limiting key 204 to move along the flow guide surface, thereby achieving a seal. The sealing ring 401 moves axially following the rotation of the valve shaft 201. Because the curvature of the guide surface increases sequentially, the sealing ring 401 moves slowly at first, then accelerates to fit against the valve plate 202 during the opening and closing process. At the moment the backflushing ends, the inner ring of the sealing ring 401 blocks the diversion channel 207, ensuring that when the valve plate 202 is fully closed, high-pressure liquid will not overflow from the diversion channel 207 and seep into the area between the bottom of the expanded diameter receiving area 102 and the sealing ring 401. Simultaneously, as the limiting key 204 moves to the highest stroke point of the guide surface of the guide key 402, the sealing ring 401 is tightly fitted against the valve plate 202, achieving a tight seal.

[0039] It is worth noting that, since the inner ring surface of the sealing ring 401 is in contact with the valve shaft 201, when the valve shaft 201 rotates from 0° to 90°, the rotation limit key 204 pushes the sealing ring 401 downward, which can also scrape off the deposits on the surface of the valve shaft 201, ensuring the smoothness of the contact surface between the valve shaft 201 and the medium. The smooth surface of the valve shaft 201 will naturally not have the problem of rotational blockage, ensuring smooth rotation.

[0040] The outer wall of the valve shaft 201 is fixed with limit keys 204 arranged in a ring array. The limit keys 204 are in contact with the flow guiding surface of the outer wall of the flow guiding key 402. The physical cooperation between the flow guiding key 402 and the limit keys 204 can realize the axial movement of the sealing ring 401 inside the expanded diameter receiving area 102.

[0041] Both the guide key 402 and the limiting key 204 are arranged in a ring array and there are four of them. The sealing ring 401 moves axially along the expansion diameter receiving area 102. The maximum longitudinal distance from the upper edge of the guide key 402 to the bottom of the guide surface is less than the travel of the sealing ring 401. When the valve plate 202 is fully open, the sealing ring 401 will be pushed to the bottom of the sealing ring 401 by the liquid flow. At this time, the limiting key 204 is also located at the bottom of the guide surface. Then, when the valve plate 202 is closed, the limiting key 204 is pressed against the top of the guide surface but does not go over it. This can ensure that the rotation angle of the valve plate 202 is limited to 0~90° and there will be no excessive rotation, which would cause the limiting key 204 to fail to press against the top of the guide surface, resulting in sealing failure.

[0042] The valve shaft 201 can only rotate between 0 and 90°. When the valve shaft 201 is at 0°, the valve plate 202 is fully open, and the limit key 204 is at the bottom of the slope of the guide key 402. When the valve shaft 201 is at 90°, the valve plate 202 is fully closed, and the limit key 204 is at the top of the slope of the guide key 402.

[0043] The guide key 402 is welded to the surface of the valve shaft 201 and is made of high-strength steel Q550 to prevent the liquid flow impact force from shearing the guide key 402.

[0044] When the valve shaft 201 rotates from 0° to 90°, which is the process of the valve plate 202 moving from fully open to fully closed, the limit key 204 pushes the sealing ring 401 from the bottom to the top of the expansion diameter receiving area 102 along the slope of the guide key 402. The sealing ring 401 then seals the gap between the valve plate 202 and the expansion diameter receiving area 102. Simultaneously, the inner ring surface of the sealing ring 401 completely seals the diversion channel 207. This prevents liquid backflow from affecting the sealing effect of the valve plate 202 and prevents long-term closure of the valve plate 202, allowing deposits to seep into the diversion channel 207 and form stubborn deposits that clog the channel, affecting the backwashing effect. During this movement, the sealing ring 401, which is in contact with the valve shaft 201, scrapes off deposits from the surface of the valve shaft 201, ensuring the smoothness of the valve shaft 201 surface. Compared to traditional butterfly valves, this design reduces the amount of liquid residue adhering to the surface of the valve shaft 201, preventing corrosion and ultimately affecting its normal rotation. When the valve plate 202 is open, the sealing ring 401 moves to the bottom of the expansion diameter receiving area 102. When the valve plate 202 is closed, the sealing ring 401 moves to the top of the expansion diameter receiving area 102 and fits against the valve plate 202 to achieve a sealing effect. This process repeats, with the sealing ring 401 moving up and down inside the expansion diameter receiving area 102. Combined with backflushing, this allows for the rapid removal of deposits and simultaneously scrapes off any adhering substances from the surface of the valve shaft 201. This completely eliminates the possibility of sediment particles accumulating in the gaps, preventing scratches on the end shaft structure surface and ensuring the end shaft structure operates in good working condition.

[0045] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A kind of high temperature and high pressure butterfly valve of erosion-resistant, anti-jamming shaft end structure, including butterfly valve body (100), valve plate (202), valve shaft (201), the inside of the valve shaft (201) is hollow, and there is cooperation gap between valve shaft (201) and valve body (101), it is characterized by: The valve shaft (201) and the valve body (101) are provided with a diameter expansion accommodating area (102); It also includes a backwashing mechanism, the backwashing mechanism includes a medium inlet (205), a one-way conduction assembly (300) and a shunt channel assembly (206), the medium inlet (205) is opened on the valve shaft (201) and communicates with the inside of the valve shaft (201), and is configured to be able to introduce the medium on the inlet side of the valve body (101); The one-way conduction assembly (300) is connected to the inside of the valve shaft (201) and corresponds to the medium inlet (205); The shunt channel assembly (206) communicates with the one-way conduction assembly (300), and is configured to be able to guide the medium conducted through the one-way conduction assembly (300) to the fitting area between the diameter expansion accommodating area (102) and the valve shaft (201), so as to realize flushing.

2. The shaft end structure of the erosion-resistant and anti-jamming high temperature and high pressure butterfly valve according to claim 1, characterized in that: The one-way conduction assembly (300) includes a limiting ring (301), a spring (303) and a piston (302), the limiting ring (301) is fixed in the inside of the valve shaft (201), the piston (302) is inserted into the middle part of the limiting ring (301) and the other end is fixed with the spring (303), and the other end of the spring (303) is fixedly connected with the axial inner wall of the valve shaft (201).

3. The shaft end structure of the erosion-resistant and anti-jamming high temperature and high pressure butterfly valve according to claim 2, characterized in that: The surface of the piston (302) is provided with through holes (304) arranged in a ring array.

4. The shaft end structure of the erosion-resistant and anti-jamming butterfly valve under high temperature and high pressure according to claim 1, characterized in that: The shunt channel assembly (206) includes a hollow area of the valve shaft (201) and a shunt channel (207) communicating with the hollow area, and the shunt channel (207) is arranged in a ring array on the surface of the valve shaft (201).

5. The shaft end structure of the erosion-resistant and anti-jamming butterfly valve under high temperature and high pressure according to claim 4, characterized in that: The lower end of the shunt channel (207) has a larger hole diameter than the upper end.

6. The shaft end structure of the erosion-resistant and anti-jamming butterfly valve under high temperature and high pressure according to claim 1, characterized in that: It also includes a sealing mechanism (400), the sealing mechanism (400) includes a sealing ring (401) and a flow guide key (402), the sealing ring (401) is sleeved on the outer wall of the valve shaft (201) and is placed in the inside of the diameter expansion accommodating area (102), and the flow guide key (402) is arranged in a ring array on the surface of the sealing ring (401).

7. The shaft end structure of the erosion-resistant and anti-jamming butterfly valve under high temperature and high pressure according to claim 6, characterized in that: The outer wall of the sealing ring (401) is fixed with a protrusion (403), the both sides of the diameter expansion accommodating area (102) are provided with a groove (103), the protrusion (403) is adaptively inserted into the groove (103), and one side of the groove (103) is designed as a half-open type.

8. The shaft end structure of the erosion-resistant and anti-jamming butterfly valve under high temperature and high pressure according to claim 6, characterized in that: The flow guide key (402) is arranged in a ring array and the surface fluid flow direction is designed as a linearly increasing type.

9. The shaft end structure of the erosion-resistant and anti-jamming butterfly valve under high temperature and high pressure according to claim 6, characterized in that: The outer wall of the valve shaft (201) is fixed with a limiting key (204) arranged in a ring array, the limiting key (204) is attached to the flow guide surface of the outer wall of the flow guide key (402), and the maximum vertical distance from the upper edge of the flow guide key (402) to the bottom end of the flow guide surface is less than the movement stroke of the sealing ring (401).

10. The shaft end structure of the erosion-resistant and anti-jamming butterfly valve under high temperature and high pressure according to claim 1, characterized in that: The upper and lower ends of the medium inlet (205) are flush with the limiting ring (301), and the opening of the medium inlet (205) is designed as a involute.

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