Low-temperature valve for low-temperature liquid nitrogen and liquid oxygen environment

Abstract

The low-temperature valve is characterized in that a valve element is integrally formed at the bottom end of a valve rod, a driving rod is welded to the bottom end of the valve element, the pipe diameter of the lower end of a valve body is shrunk to form a liquid outlet pipe, a one-way piece is installed in the liquid outlet pipe, and a liquid inlet pipe is welded to the right end of the outer ring of the valve body; an emptying pipe is welded to the left end of the outer ring of the liquid outlet pipe, an emptying structure is installed in the emptying pipe, the emptying structure and the one-way piece are both connected with the driving rod, the one-way piece is installed in the liquid outlet pipe of the valve body, so that the low-position valve has the two functions of a stop valve and a one-way valve at the same time, the driving rod is arranged below the valve element, and therefore the low-position valve is convenient to use. The limiting structure used for limiting the one-way element is arranged in the one-way piece, and the limiting structure is connected with the driving rod through the downward pressing rod, so that when the valve element is cut off and liquid nitrogen and liquid oxygen stop flowing, the one-way piece can be synchronously closed, the two ends of the one-way piece cannot flow, and generated bubbles are prevented from entering equipment.

Description

Technical Field

[0001] The present invention relates to the field of valves, and in particular to a cryogenic valve used in a cryogenic liquid nitrogen and liquid oxygen environment. Background Art

[0002] During the transportation of liquid nitrogen, liquid oxygen, etc., due to the low temperature, cryogenic valves are usually required. In order to avoid backflow during the liquid transportation process, a one-way valve is usually installed at the liquid outlet of the cryogenic valve to ensure that the liquid does not flow back. Because there is still a distance between the one-way valve and the outlet of the cryogenic valve, when the cryogenic valve is closed, the liquid at the outlet of the cryogenic valve cannot push open the valve core in the one-way valve due to insufficient pressure. This causes a certain amount of cryogenic liquid to remain between the outlet of the cryogenic valve core and the inlet of the one-way valve core. The boiling points of liquid nitrogen and liquid oxygen are much lower than room temperature. When the cryogenic liquid is left in a non-completely insulated environment for a long time, it may quickly absorb heat and reach boiling point, causing the liquid inside to violently vaporize and form bubbles. The volume of liquid nitrogen expands about 700 times when it vaporizes. The rapid phase change process will intensify the bubble generation rate and intensity, thereby increasing the pressure in this space. In severe cases, the increased gas pressure may cause an explosion. In mild cases, the increased gas pressure may push open the valve core of the one-way valve, allowing these gases to enter the equipment and mix with liquid nitrogen and liquid oxygen. Excessive bubbles will cause liquid foam entrainment, which may block the tower plate ducts or gas phase channels, and in severe cases, induce liquid flooding accidents. To this end, a cryogenic valve for low-temperature liquid nitrogen and liquid oxygen environments is designed. Summary of the Invention

[0003] The present invention proposes a cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment, which solves the above-mentioned problem.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions: A cryogenic valve for use in cryogenic liquid nitrogen and liquid oxygen environments, comprising a long-necked valve cover, the top end of which is bolted with a pneumatic actuator, the bottom end of which is bolted with a valve body, a valve stem slidably mounted up and down inside the long-necked valve cover, the top end of the valve stem being connected to the pneumatic shaft of the pneumatic actuator, the pneumatic actuator being an AT pneumatic actuator with its own pneumatic shaft, a valve core integrally formed at the bottom end of the valve stem, the valve core extending into the valve body, and a drive rod welded to the bottom end of the valve core; The diameter of the lower end of the valve body is contracted to form a liquid outlet pipe, a one-way piece is installed in the liquid outlet pipe, a liquid inlet pipe is welded to the right end of the outer ring of the valve body, an emptying pipe is welded to the left end of the outer ring of the liquid outlet pipe, an emptying structure is installed in the emptying pipe, and the emptying structure and the one-way piece are both connected to the driving rod.

[0005] Preferably, a fixing ring is welded to the outer ring of the valve stem, a bellows 1 is sleeved on the outer ring of the valve stem, the top of the bellows 1 is welded to the fixing ring, a flange is provided at the bottom end of the bellows 1, the flange is pressed between the bottom end of the long-neck valve cover and the upper end of the valve body, and the three are fixed by bolts and nuts. The bellows 1 is a metal bellows, the top of which is welded to the fixing ring, and there is no gap between the two. The bottom end is sealed with the bottom end of the long-neck valve cover and the upper end of the valve body. Compared with traditional seals, the bellows 1 is used as a seal, so that the valve stem can move up and down normally, while also avoiding deformation of the seal in a low-temperature environment, thereby improving the sealing effect. The lower end of the valve stem is sleeved with a guide member, which is fixed on the upper part of the valve body. The top outer ring of the guide member is integrally formed with a ring. An annular groove is opened at the top of the valve body. The ring is placed in the annular groove, and the top of the ring is tightly pressed against the lower end of the flange of the bellows.

[0006] Preferably, the one-way member includes a fixed tube fixed to the bottom end of the liquid outlet pipe, annular frames are welded to the upper and lower ends of the fixed tube respectively, a guide sleeve is welded between the upper and lower annular frames, the guide sleeve is slidably sleeved with a one-way core, a lifting spring is sleeved on the guide sleeve, the upper and lower ends of the lifting spring are respectively in contact with the bottom end of the one-way core and the upper surface of the lower annular frame, the lifting spring makes the one-way core always have a tendency to move upward, a limiting piece for limiting the one-way core is installed in the guide sleeve, a pressing rod is fixed below the driving rod, and the pressing rod is connected to the limiting piece; The outer ring of the lower pressure rod is sleeved with a bellows 2, the bottom end of the bellows 2 is welded to the outer ring of the lower pressure rod, and the top end of the bellows 2 is welded and fixed to the top end of the guide sleeve, with no gap between the two, thereby improving the sealing effect between the lower pressure rod and the guide sleeve, so that the liquid nitrogen and liquid oxygen above the guide sleeve cannot penetrate into the lower part of the guide sleeve.

[0007] Preferably, the upper portion of the interior of the fixed tube is thickened to form a tapered surface. The tapered surface and the outer ring surface of the one-way core both have a tapered cross-section. When the one-way core moves upward, the outer ring surface of the one-way core can be tightly pressed against the tapered surface. An extrusion sealing structure is adopted between the two to prevent deformation and leakage due to low temperature. The upper half of the inner ring of the one-way core is designed with a conical structure to form a sealing surface, and the outer ring surface of the guide sleeve is partially protruded and thickened to form a sealing joint. The sealing surface and the sealing joint cross-section are conical structures. After the one-way core moves upward, the sealing surface can be tightly pressed against the sealing joint to form a sealing structure.

[0008] Preferably, the outer ring of the guide sleeve is provided with four groups of through-holes distributed in a circular array, the limiting member includes a plurality of limiting blocks, and the plurality of limiting blocks are respectively slidably inserted into the through-holes, a guide block is fixed to the bottom end of the limiting block, and a support ring is fixed to the inner ring of the guide sleeve, and the support ring is penetrated from top to bottom to form a guide groove distributed in a circular pattern, and the guide block is slidably inserted into the guide groove.

[0009] Preferably, the lower half of the inner ring surface of the one-way core is designed with a conical structure to form an abutment surface, and the arc-shaped structure of the outward side of the limit block is designed to form a limit inclined surface. When the multiple limit blocks move away from each other and outward, the limit inclined surface can contact the abutment surface and push the one-way core to move upward to form a sealing structure. The arc-shaped structure on the inward side of the limit block is designed to form a downward pressing slope, and the arc-shaped surface at the bottom end of the lower pressure rod is designed to form an arc surface. When the lower pressure rod moves downward, the arc surface at the bottom end of the lower pressure rod can contact the downward pressing slope, thereby pushing the four limit blocks to move outward synchronously. The limit blocks moving outward will contact the one-way core and limit its downward movement, thereby ensuring that the gas in the space between the valve core and the one-way core cannot overflow into the equipment.

[0010] Preferably, the emptying structure includes a guide ring seat fixed in the emptying pipe, a guide column is inserted into the guide ring seat for sliding left and right, a sealing head is integrally formed at the left end of the guide column, and an opening and closing part and a pressing part are welded on the upper and lower sides of the right end of the guide column respectively, and the opening and closing part and the pressing part are both slidably connected to the driving rod, and the cross-section of the emptying pipe is a convex structure, and the sealing head structure is the same as the cross-section of the emptying pipe. When the sealing head moves to the left, it can abut against the inner wall of the emptying pipe to form a sealing structure, and when it moves to the right, a gap will be left, thereby discharging the gas.

[0011] Preferably, the inclined surface of the upper left side of the opening and closing part is designed to form an opening and closing inclined surface, and the lower half of the opening and closing part is vertically downward to form a vertical surface. An L-shaped block is welded to the left side of the outer ring of the driving rod, and the lower end of the L-shaped block is cut away to form an opening surface with an inclined design. The driving rod moves downward with the valve core, and when the valve core is about to be completely closed, the opening and closing inclined surface will contact the opening surface and push the L-shaped block to move to the right, thereby causing the entire guide column and the sealing head to move to the right, and a gap is formed between the sealing head and the inner wall of the exhaust pipe.

[0012] Preferably, a pressing bevel is formed on the portion on the right side surface of the pressing portion, and an abutment block is welded on the left side of the outer ring of the driving rod. The right side surface of the opening and closing portion is coplanar with the right side surface of the guide column. When the driving rod moves upward, the abutment block will move upward along the pressing bevel, and will push the guide column to the left during the upward movement, thereby causing the sealing head to seal the drain pipe. When the abutment block contacts the right side surface of the guide column, the sealing head is in a sealed state. When the abutment block continues to move upward, it contacts the right side surface of the opening and closing portion and will not push the sealing head, thereby avoiding damage caused by excessive pressure.

[0013] Beneficial effects of the present invention: 1. By installing a one-way piece in the liquid outlet pipe of the valve body, the cryogenic valve has both the functions of a shut-off valve and a one-way valve. A driving rod is provided below the valve core. The one-way piece is provided with a limiting structure for limiting the one-way core. The limiting structure is connected to the driving rod through a pressing rod. When the valve core is shut off and the liquid nitrogen and liquid oxygen stop flowing, the one-way piece will also be closed synchronously. No flow can occur at both ends, preventing the generated bubbles from entering the equipment. 2. By setting an emptying pipe on the liquid outlet pipe, installing an emptying structure in the emptying pipe, and connecting the emptying structure to the valve core through a driving rod, when the valve core is cut off and the liquid nitrogen and liquid oxygen stop flowing, the emptying structure will also be forced to open synchronously, which makes the space between the one-way member and the valve core open, so that the gas generated inside can be discharged, thereby improving safety; 3. The emptying structure and the one-way part are linked by a driving rod and a pressing rod. When the emptying structure is opened, the one-way part is in a closed state. When the one-way part is opened, the emptying structure must be in a closed state. This ensures that when the cryogenic valve is normally transporting liquid nitrogen and liquid oxygen, the internal liquid nitrogen and liquid oxygen will not leak, thereby improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a schematic cross-sectional view of a cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment proposed by the present invention; Figure 2 A cross-sectional view of a cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment, as proposed by the present invention; Figure 3 This is a partial cross-sectional schematic diagram of a cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment proposed by the present invention; Figure 4 for Figure 3 A partial enlarged schematic diagram; Figure 5 for Figure 2 A partial enlarged schematic diagram; Figure 6 for Figure 5 Structural diagram of the one-way component; Figure 7 for Figure 6 Exploded view of the one-way component; Figure 8 for Figure 5 Schematic diagram of the structure of the middle emptying structure and valve core.

[0015] Reference numerals in the figure: 1, pneumatic actuator; 2, long-neck valve cover; 3, valve body; 31, liquid outlet pipe; 32, liquid inlet pipe; 33, drain pipe; 4, valve stem; 401, fixing ring; 402, guide member; 41, bellows 1; 42, valve core; 43, driving rod; 431, L-shaped block; 432, opening surface; 433, abutment block; 5, one-way member; 51, fixing pipe; 511, tapered surface; 52, annular frame; 53, guide sleeve; 531, sealing surface; 532 , through-mouth; 54, lifting spring; 55, one-way core; 551, abutment surface; 552, sealing surface; 56, pressing rod; 561, bellows 2; 57, limit block; 571, guide block; 572, limit slope; 573, pressing slope; 58, support ring; 581, guide groove; 6, emptying structure; 61, guide ring seat; 62, sealing head; 63, guide column; 64, opening and closing part; 641, opening and closing slope; 65, pressing part; 651, pressing slope. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0017] Reference Figures 1-8 A cryogenic valve for cryogenic liquid nitrogen and liquid oxygen environments includes a long-necked valve cover 2, the top end of the long-necked valve cover 2 is bolted with a pneumatic actuator 1, the lower end of the long-necked valve cover 2 is bolted with a valve body 3, a valve stem 4 is slidably mounted inside the long-necked valve cover 2, the top end of the valve stem 4 is connected to the pneumatic shaft of the pneumatic actuator 1, the pneumatic actuator 1 adopts an AT pneumatic actuator with a pneumatic shaft inside, the bottom end of the valve stem 4 is integrally formed with a valve core 42, the valve core 42 extends into the valve body 3, and the bottom end of the valve core 42 is welded with a drive rod 43; The diameter of the lower end of the valve body 3 is contracted to form a liquid outlet pipe 31, in which a one-way member 5 is installed. A liquid inlet pipe 32 is welded to the right end of the outer ring of the valve body 3, and an emptying pipe 33 is welded to the left end of the outer ring of the liquid outlet pipe 31. An emptying structure 6 is installed in the emptying pipe 33. The emptying structure 6 and the one-way member 5 are both connected to the driving rod 43.

[0018] Reference Figure 2 、 Figure 3, the outer ring of the valve stem 4 is welded with a fixing ring 401, and the outer ring of the valve stem 4 is sleeved with a bellows 41. The top of the bellows 41 is welded to the fixing ring 401, and the bottom end of the bellows 41 is provided with a flange, which is pressed between the bottom end of the long-necked valve cover 2 and the upper end of the valve body 3. The three are fixed by bolts and nuts. The bellows 41 is a metal bellows, the top of which is welded to the fixing ring 401, and there is no gap between the two. The bottom end is sealed with the bottom end of the long-necked valve cover 2 and the upper end of the valve body 3. Compared with traditional seals, the bellows 41 is used as a seal, so that the valve stem 4 can move up and down normally, while also avoiding the deformation of the seal in a low temperature environment, thereby improving the sealing effect; The lower end of the valve stem 4 is sleeved with a guide member 402, which is fixed on the upper part of the inside of the valve body 3. The top outer ring of the guide member 402 is integrally formed with a ring. An annular groove is opened at the top of the valve body 3, and the ring is placed in the annular groove. The top of the ring is tightly pressed against the lower end of the flange of the bellows 41.

[0019] Reference Figure 6-Figure 8 The one-way member 5 includes a fixed tube 51 fixed to the bottom end of the liquid outlet pipe 31, annular frames 52 are welded to the upper and lower ends of the fixed tube 51, a guide sleeve 53 is welded between the upper and lower annular frames 52, and the guide sleeve 53 is slidably sleeved with a one-way core 55. A lifting spring 54 is sleeved on the guide sleeve 53, and the upper and lower ends of the lifting spring 54 are respectively abutted against the bottom end of the one-way core 55 and the upper surface of the lower annular frame 52. The lifting spring 54 makes the one-way core 55 always have a tendency to move upward. A limiting member for limiting the one-way core 55 is installed in the guide sleeve 53, and a pressing rod 56 is fixed below the driving rod 43, and the pressing rod 56 is connected to the limiting member; The outer ring of the lower pressure rod 56 is connected with the bellows 2 561, the bottom end of the bellows 2 561 is welded to the outer ring of the lower pressure rod 56, and the top end of the bellows 2 561 is welded and fixed to the top end of the guide sleeve 53. There is no gap between the two, which improves the sealing effect between the lower pressure rod 56 and the guide sleeve 53, so that the liquid nitrogen and liquid oxygen above the guide sleeve 53 cannot penetrate into the bottom of the guide sleeve 53.

[0020] The upper portion of the fixed tube 51 is thickened to form a tapered surface 511. Both the tapered surface 511 and the outer surface of the one-way core 55 have conical cross-sections. When the one-way core 55 moves upward, the outer surface of the one-way core 55 can be tightly pressed against the tapered surface 511. An extrusion seal is employed between the two to prevent deformation and leakage caused by low temperatures. The upper half of the inner ring of the one-way core 55 is designed with a conical structure to form a sealing surface 552, and the outer ring surface of the guide sleeve 53 is partially protruded and thickened to form a sealing joint 531. The cross-sections of the sealing surface 552 and the sealing joint 531 are conical structures. After the one-way core 55 moves upward, the sealing surface 552 can be tightly pressed against the sealing joint 531 to form a sealing structure.

[0021] The outer ring of the guide sleeve 53 is provided with four groups of through-holes 532 distributed in a circular array, and the limiting parts include multiple limiting blocks 57, and the multiple limiting blocks 57 are respectively slidably inserted into the through-holes 532. The bottom end of the limiting block 57 is fixed with a guide block 571, and the inner ring of the guide sleeve 53 is fixed with a support ring 58. The support ring 58 passes through the upper and lower parts to form a guide groove 581 distributed in a circular manner. The guide block 571 is slidably inserted into the guide groove 581.

[0022] The lower half of the inner ring surface of the one-way core 55 is designed with a conical structure to form an abutment surface 551. The outward-facing arc structure of the limit block 57 forms a limit slope 572. When the multiple limit blocks 57 move away from each other and outward, the limit slope 572 can contact the abutment surface 551 and push the one-way core 55 upward to form a sealing structure. The arc-shaped structure on the inward side of the limit block 57 is designed to form a downward pressing slope 573, and the arc-shaped surface at the bottom end of the lower pressure rod 56 is designed to form an arc surface. When the lower pressure rod 56 moves downward, the arc surface at the bottom end of the lower pressure rod 56 can contact the downward pressing slope 573, thereby pushing the four limit blocks 57 to move outward synchronously. The limit blocks 57 moving outward will contact the one-way core 55 and limit its downward movement, thereby ensuring that the gas in the space between the valve core 42 and the one-way core 55 cannot overflow into the equipment.

[0023] Reference Figure 4-Figure 8 The emptying structure 6 includes a guide ring seat 61 fixed in the emptying pipe 33, and a guide column 63 is inserted into the guide ring seat 61 for sliding left and right. The left end of the guide column 63 is integrally formed with a sealing head 62, and the upper and lower sides of the right end of the guide column 63 are welded with an opening and closing part 64 and a pressing part 65 respectively. The opening and closing part 64 and the pressing part 65 are both slidably connected to the driving rod 43. The cross-section of the emptying pipe 33 is a convex structure, and the sealing head 62 has the same structure as the cross-section of the emptying pipe 33. When the sealing head 62 moves to the left, it can abut against the inner wall of the emptying pipe 33 to form a sealing structure. When it moves to the right, a gap will be left, and the gas will be discharged.

[0024] The upper left half of the opening and closing portion 64 is designed with an inclined surface 641, and the lower half of the opening and closing portion 64 is vertically downward to form a vertical surface. An L-shaped block 431 is welded to the left side of the outer ring of the driving rod 43, and a portion of the lower end of the L-shaped block 431 is cut away to form an inclined opening surface 432. The driving rod 43 moves downward together with the valve core 42, and when the valve core 42 is about to be fully closed, the opening and closing inclined surface 641 will contact the opening surface 432. Then the valve core 42 continues to move downward. At this time, the L-shaped block 431 located on the driving rod 43 moves downward along with the valve core 42 and the driving rod 43. The opening surface of the downward-moving L-shaped block 431 will squeeze the opening and closing inclined surface 641 on the opening and closing portion 64, thereby pushing the opening and closing portion 64 to move rightward, thereby causing the entire guide column 63 and the sealing head 62 to move rightward until the valve core 42 moves to the bottom, causing the valve body to be fully closed, and a gap to be formed between the sealing head 62 and the inner wall of the exhaust pipe 33.

[0025] The right side surface of the pressing part 65 is cut away to form a pressing bevel 651, and the left side of the outer ring of the driving rod 43 is welded with an abutment block 433. The right side surface of the opening and closing part 64 is coplanar with the right side surface of the guide column 63. When the driving rod 43 moves upward, the abutment block 433 will move upward along the pressing bevel 651, and will push the guide column 63 to move to the left during the upward movement, thereby causing the sealing head 62 to seal the exhaust pipe 33. When the abutment block 433 contacts the right side surface of the guide column 63, the sealing head 62 is in a sealed state at this time. When the abutment block 433 continues to move upward, it contacts the right side surface of the opening and closing part 64 and will not push the sealing head 62, thereby avoiding damage caused by excessive pressure.

[0026] Working principle: In actual use, the liquid outlet pipe 31 is connected to the liquid inlet of the required equipment through a pipeline, the liquid inlet pipe 32 is connected to the pipeline for conveying liquid nitrogen and liquid oxygen through a pipeline, and the exhaust pipe 33 is connected to the vacuum pump through a pipeline. The pneumatic actuator 1 moves the valve stem 4 upward through the pneumatic shaft, thereby opening the valve core 42. At the same time, when the valve core 42 moves upward, the pressing rod 56 located below the driving rod 43 will also move upward synchronously, and the bottom end of the pressing rod 56 will be out of contact with the pressing inclined surfaces 573 on the inner side walls of the plurality of limit blocks 57, that is, the pressing rod 56 releases the contact limit on the plurality of limit blocks 57, and the limit blocks 57 can now move freely inward. When the valve core 42 is rising, the driving rod 43, the abutting block 433 and the L-shaped block 431 below the valve core 42 will also move upward together. When the abutting block 433 moves upward, the abutting block 433 will move upward along the pressing inclined surface 651. As the abutting block 433 gradually rises, the guide column 63 will be pushed to the left during the upward movement of the abutting block 433, thereby causing the sealing head 62 to seal the exhaust pipe 33. When the abutting block 433 contacts the right side surface of the guide column 63, the sealing head 62 is in a sealed state. When the abutting block 433 continues to move upward, the abutting block 433 contacts the right side surface of the opening and closing portion 64, and will not push the sealing head 62, thereby avoiding damage caused by excessive pressure. After the valve core 42 is opened, the interior of the valve body 3 is connected with the liquid outlet pipe 31, thereby making the liquid outlet pipe 31 connected with the liquid inlet pipe 32, and the liquid nitrogen and liquid oxygen entering the valve body 3 through the liquid inlet pipe 32 can flow into the liquid outlet pipe 31. At this time, the sealing head 62 seals the drain pipe 33, and the liquid nitrogen and liquid oxygen will not flow out through the drain pipe 33. At the beginning, the one-way core 55 blocks the liquid outlet 31 under the action of the lifting spring 54. As the liquid nitrogen and liquid oxygen in the liquid outlet pipe 31 increase, the internal pressure gradually increases, and the liquid nitrogen and liquid oxygen will push the one-way core 55 to move downward. During the downward movement of the one-way core 55, the conical surface 551 of the one-way core 55 will squeeze the limiting inclined surface 572 of the limiting block 57, thereby causing the multiple limiting blocks 57 to retract inwardly into the guide sleeve 53, and the lifting spring 54 is compressed downward, and the liquid nitrogen and liquid oxygen can be discharged through the space between the one-way core 55 and the inner wall of the fixed pipe 51 and flow into the corresponding equipment; When liquid nitrogen and liquid oxygen flow back, the lifting spring 54 will cause the one-way core 55 to move upward, and as the liquid nitrogen and liquid oxygen increase and the pressure increases, the pressing force between the outer ring surface of the one-way core 55 and the tapered surface 511, and the pressing force between the sealing surface 552 of the one-way core 55 and the sealing surface 531 of the guide sleeve 53 will become increasingly greater, thereby achieving a better sealing effect and preventing backflow.

[0027] The pneumatic actuator 1 moves the valve stem 4 downward through the pneumatic shaft, thereby closing the valve core 42, and the low-temperature valve can be cut off. When the valve core 42, the driving rod 43 and the lower pressing rod 56 move downward, the arc-shaped structure of the inner side of the limit block 57 forms a downward pressing inclined surface 573, and the arc surface of the bottom end of the lower pressing rod 56 is designed to form an arc surface. When the lower pressing rod 56 moves downward together with the driving rod 43, the arc surface of the bottom end of the lower pressing rod 56 can contact the downward pressing inclined surface 573, thereby pushing the four limit blocks 57 to move outward synchronously. The limit blocks 57 moving outward will contact the one-way core 55 and limit its downward movement. In this way, when the valve core 42 is closed, the one-way core 55 can also force the one-way member 5 to close and cannot open, thereby ensuring that the gas in the space between the valve core 42 and the one-way core 55 cannot overflow into the equipment. At the same time, the driving rod 43 moves downward together with the valve core 42, and when the valve core 42 is about to be completely closed, the opening and closing inclined surface 641 will contact the opening surface 432 and push the L-shaped block 431 to move to the right, thereby causing the entire guide column 63 and the sealing head 62 to move to the right, and a gap is formed between the sealing head 62 and the inner wall of the exhaust pipe 33, which makes the space between the one-way member 5 and the valve core 42 in an open state, so that the gas generated inside can be discharged, and the interior can be put into a vacuum state through the vacuum pump, thereby improving safety.

[0028] By installing a one-way member 5 in the liquid outlet pipe 31 of the valve body 3, the cryogenic valve has both the functions of a shut-off valve and a one-way valve, and a driving rod 43 is provided below the valve core 42. The one-way member 5 is provided with a limiting structure for limiting the one-way core 55. The limiting structure is connected to the driving rod 43 via a pressing rod 56. When the valve core 42 is shut off and the flow of liquid nitrogen and liquid oxygen stops, the one-way member 5 will also be closed synchronously, and no flow can occur at both ends, thereby preventing the generated bubbles from entering the equipment. By providing an emptying pipe 33 on the liquid outlet pipe 31, an emptying structure 6 is installed in the emptying pipe 33, and the emptying structure 6 is connected to the valve core 42 via a driving rod 43. When the valve core 42 is cut off to stop the flow of liquid nitrogen and liquid oxygen, the emptying structure 6 will also be forced to open synchronously, so that the space between the one-way member 5 and the valve core 42 is in an open state, allowing the gas generated inside to be discharged, thereby improving safety. The emptying structure 6 and the one-way member 5 are linked by a driving rod 43 and a pressing rod 56. When the emptying structure 6 is opened, the one-way member 5 is in a closed state. When the one-way member 5 is opened and working, the emptying structure 6 must be in a closed state. This ensures that when the cryogenic valve is normally transporting liquid nitrogen and liquid oxygen, the internal liquid nitrogen and liquid oxygen will not leak, thereby improving safety.

[0029] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0030] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0031] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A cryogenic valve for use in a cryogenic liquid nitrogen or liquid oxygen environment, characterized in that: The invention comprises a long-necked valve cover (2), wherein the top end of the long-necked valve cover (2) is fixed with a pneumatic actuator (1), the bottom end of the long-necked valve cover (2) is fixed with a valve body (3), a valve stem (4) is mounted inside the long-necked valve cover (2) for sliding up and down, the top end of the valve stem (4) is connected to the pneumatic shaft of the pneumatic actuator (1), and the valve stem (4) has a pneumatic shaft inside, the bottom end of the valve stem (4) is integrally formed with a valve core (42), the valve core (42) extends into the valve body (3), and the bottom end of the valve core (42) is welded with a driving rod (43); The diameter of the lower end of the valve body (3) is contracted to form a liquid outlet pipe (31), a one-way member (5) is installed in the liquid outlet pipe (31), a liquid inlet pipe (32) is welded to the right end of the outer ring of the valve body (3), and an exhaust pipe (33) is welded to the left end of the outer ring of the liquid outlet pipe (31), an exhaust structure (6) is installed in the exhaust pipe (33), and the exhaust structure (6) and the one-way member (5) are both connected to the driving rod (43).

2. A cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 1, characterized in that: The outer ring of the valve stem (4) is welded with a fixing ring (401), the outer ring of the valve stem (4) is sleeved with a bellows (41), the top of the bellows (41) is welded to the fixing ring (401), and the bottom end of the bellows (41) is provided with a flange, which is pressed between the bottom end of the long-necked valve cover (2) and the upper end of the valve body (3); The lower end of the valve stem (4) is sleeved with a guide member (402), and the guide member (402) is fixed above the interior of the valve body (3).

3. The cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 1, characterized in that: The one-way member (5) includes a fixed tube (51) fixed to the bottom end of the liquid outlet pipe (31), an annular frame (52) is welded to the upper and lower ends of the fixed tube (51), a guide sleeve (53) is welded between the upper and lower annular frames (52), the guide sleeve (53) is slidably sleeved with a one-way core (55), a lifting spring (54) is sleeved on the guide sleeve (53), the upper and lower ends of the lifting spring (54) are respectively in contact with the bottom end of the one-way core (55) and the upper surface of the lower annular frame (52), a limiting member for limiting the one-way core (55) is installed in the guide sleeve (53), a lower pressing rod (56) is fixed below the driving rod (43), and the lower pressing rod (56) is connected to the limiting member; The outer ring of the lower pressure rod (56) is sleeved with a second bellows (561), the bottom end of the second bellows (561) is welded to the outer ring of the lower pressure rod (56), and the top end of the second bellows (561) is welded and fixed to the top end of the guide sleeve (53).

4. A cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 3, characterized in that: The upper portion of the inner wall of the fixed tube (51) is thickened to form a tapered surface (511), and the tapered surface (511) and the outer ring surface cross-section of the one-way core (55) both have a tapered structure; The upper half of the inner ring of the one-way core (55) is designed with a conical structure to form a sealing surface (552), and the outer ring surface of the guide sleeve (53) is partially convex and thickened to form a sealing joint (531). The cross-sections of the sealing surface (552) and the sealing joint (531) are conical structures.

5. A cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 4, characterized in that: The outer ring of the guide sleeve (53) is provided with four groups of through-holes (532) distributed in an annular array, the limiting member includes a plurality of limiting blocks (57), and the plurality of limiting blocks (57) are respectively slidably inserted into the through-holes (532), and a guide block (571) is fixed at the bottom end of the limiting block (57), and the inner ring of the guide sleeve (53) is fixed with a support ring (58), and the support ring (58) is penetrated from top to bottom to form a guide groove (581) distributed in an annular manner around it, and the guide block (571) is slidably inserted into the guide groove (581).

6. A cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 5, characterized in that: The lower half of the inner ring surface of the one-way core (55) is designed with a conical structure to form an abutment surface (551), and the outward-facing arc structure of the limiting block (57) is designed to form a limiting inclined surface (572); The arc-shaped structure on the inward side of the limit block (57) is designed to form a downward pressing inclined surface (573), and the arc-shaped surface at the bottom end of the downward pressing rod (56) is designed to form an arc surface.

7. The cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 1, characterized in that: The emptying structure (6) includes a guide ring seat (61) fixed in the emptying pipe (33), a guide column (63) is slidably inserted on the guide ring seat (61), a sealing head (62) is integrally formed at the left end of the guide column (63), and an opening and closing portion (64) and a pressing portion (65) are welded on the upper and lower sides of the right end of the guide column (63), respectively, and the opening and closing portion (64) and the pressing portion (65) are both slidably connected to the driving rod (43).

8. The cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 7, characterized in that: The upper left half of the opening and closing portion (64) is designed with an inclined surface to form an opening and closing inclined surface (641), and the lower half of the opening and closing portion (64) is vertically downward to form a vertical surface. An L-shaped block (431) is welded to the left side of the outer ring of the driving rod (43), and a portion of the lower end of the L-shaped block (431) is cut away to form an opening surface (432) with an inclined design.

9. The cryogenic valve for use in a cryogenic liquid nitrogen and liquid oxygen environment according to claim 8, characterized in that: A pressing bevel (651) is formed by cutting away a portion of the right side surface of the pressing portion (65), an abutment block (433) is welded to the left side of the outer ring of the driving rod (43), and the right side surface of the opening and closing portion (64) is coplanar with the right side surface of the guide column (63).

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