Three-eccentric butterfly valve with bidirectional metal hard sealing structure

Abstract

The application discloses a three-eccentric butterfly valve with a bidirectional metal hard sealing structure, relates to the butterfly valve manufacturing technical field, and is a research on how to improve the structure of the butterfly valve in a high-temperature working condition to avoid thermal expansion deformation and to have stable sealing performance. The three-eccentric butterfly valve applied to the high-temperature working condition is improved. In the valve plate closing process, the flow passage passing area gradually decreases, the fluid pressure gradually increases, the metal static sealing structure is arranged at the contact part of the valve seat and the valve plate, and the purpose is to keep the sealing part in the valve body in a stable dynamic sealing state after being impacted by high pressure, to avoid the deformation of the sealing surface caused by pressure change and to avoid the leakage phenomenon, and to make the packing far away from the flow passage center by adopting the symmetrical heat dissipation valve cover structure in the high-temperature working condition. The butterfly spring structure capable of compensating the axial deformation of the valve shaft is used to provide displacement compensation of the valve shaft under the high-temperature deformation, and the bottom valve cover and the valve shaft are prevented from being stuck in the high-temperature working condition under the conventional structure.

Description

Technical Field

[0001] The present invention relates to the technical field of butterfly valves, in particular to a triple-eccentric butterfly valve adopting a bidirectional metal hard sealing structure. Background Art

[0002] The triple-eccentric butterfly valve has a valve stem axis that deviates from both the disc center and the body center, and the valve seat rotation axis is at a certain angle to the valve body channel axis. The working conditions of valves in the metallurgical industry are complex and diverse, involving high temperature, high pressure, corrosive media, dust and particulate matter and other extreme environments. Among them, blast furnace ironmaking, converters, continuous casting, and steel rolling heating furnaces are characterized by high temperature conditions. Valves need to face problems such as high-temperature oxidation resistance, bearing seizure and thermal fatigue caused by thermal expansion deformation.

[0003] Referring to the Chinese patent publication number CN216923231U, a wedge-shaped sealing ring and a pressure plate structure are used to achieve bidirectional sealing performance. However, when used in high-temperature working conditions, the valve shaft and the bottom cover are still stuck due to high-temperature expansion and deformation. More importantly, when the valve plate is closed, the flow area gradually decreases and the fluid pressure gradually increases. When the sealing part is subjected to high-pressure impact, it is difficult to form a progressive dynamic seal, and the risk of leakage still exists.

[0004] Therefore, this application proposes a solution to the research on how to improve the structure of butterfly valves in high-temperature working conditions to avoid thermal expansion deformation and have stable sealing performance. Summary of the Invention

[0005] The purpose of the present invention is to provide a three-eccentric butterfly valve with a bidirectional metal hard seal structure, which is used to solve the problem of how to improve the structure of the butterfly valve in high-temperature working conditions to avoid thermal expansion deformation and ensure stable sealing performance;

[0006] Improvements have been made to the triple-eccentric butterfly valve used in high-temperature working conditions. The flow passage area gradually decreases and the fluid pressure gradually increases during the closing process of the valve disc. A metal static seal structure is set at the contact point between the valve seat and the valve disc to maintain a stable dynamic seal state even after the sealing part of the valve body is subjected to high-pressure impact, avoiding deformation of the sealing surface caused by pressure changes and causing leakage.

[0007] In addition, a symmetrically arranged heat dissipating valve cover structure is used in high-temperature working conditions to place the packing away from the center of the flow channel. In combination with a butterfly spring structure that can compensate for the axial deformation of the valve shaft, displacement compensation of the valve shaft under high-temperature deformation is provided, thereby improving the phenomenon of the bottom valve cover and the valve shaft being stuck in high-temperature working conditions under conventional structures.

[0008] The object of the present invention can be achieved by the following technical solution: a three-eccentric butterfly valve with a bidirectional metal hard seal structure, comprising a valve seat and a valve plate, wherein the side of the valve plate near the fluid inlet is a groove with a cross section of a bad arc, and the upper and lower ends of the valve seat are symmetrically provided with heat dissipation components;

[0009] An upper valve stem is rotatably provided at the upper end of the middle portion of the valve seat, and a lower valve stem extending to the outside of the valve seat is installed at the lower end of the upper valve stem; a metal hard sealing structure is stacked on the outer peripheral side of the valve plate, and a conical lock plate and an outer pressure-bearing plate are installed on the metal hard sealing structure; the valve seat is provided with a conical passing surface corresponding to the fluid passage, and an asymptotic contact surface is provided on the outer peripheral side of the valve plate; and a supplementary sealing surface and a locking contact surface adapted to the conical passing surface are respectively provided on the outer sides of the conical lock plate and the outer pressure-bearing plate;

[0010] A turbulence port is provided between the supplementary sealing surface and the outer end of the tapered passing surface, and a centrifugal port is provided between the locking contact surface and the outer end of the supplementary sealing surface.

[0011] It is further configured as follows: the heat dissipation component includes an upper heat dissipation valve cover and a lower heat dissipation valve cover, and the upper heat dissipation valve cover and the lower heat dissipation valve cover are symmetrically covered at both ends of the upper valve stem and lower valve stem assembly.

[0012] It is further configured as follows: a bottom support bracket is installed at the lower end of the lower heat dissipation valve cover at the bottom, a bottom bearing for rotating support of the lower valve stem is installed in the bottom support bracket, and a butterfly spring component connected to the bottom support bracket is installed at the lower end of the lower valve stem.

[0013] It is further configured as follows: a mounting seat is installed on the upper end of the valve seat, a filler is filled inside the mounting seat close to the valve seat, and a pressure cover connected to the mounting seat is encapsulated on the filler.

[0014] It is further configured as follows: an upper shaft sleeve is embedded in the upper end of the valve seat, and a lower shaft sleeve is embedded in the valve seat near the lower heat dissipation valve cover, and the upper shaft sleeve and the lower shaft sleeve are used together for rotating support of the upper valve stem.

[0015] It is further configured that: a sealing gasket is installed between the valve plate and the outer circumference of the conical lock plate, and the outer circumference of the sealing gasket does not exceed the conical annular surface of the conical lock plate.

[0016] It is further configured as follows: a dust ring is provided on the lower end of the lower shaft sleeve, and the dust ring is connected to the upper end of the lower heat dissipation valve cover.

[0017] It is further configured as follows: a washer is installed on the outer side of the bottom of the bottom support bracket corresponding to the butterfly spring component, and the inner ring side of the washer is in contact with the outer side of the bottom of the butterfly spring component.

[0018] The present invention has the following beneficial effects:

[0019] 1. The present invention improves a triple-eccentric butterfly valve for use in high-temperature operating conditions. During valve plate closing, the flow passage area gradually decreases and the fluid pressure gradually increases. A metal static seal structure is provided at the contact point between the valve seat and the valve plate to maintain a stable dynamic seal even after the sealing portion of the valve body is subjected to high-pressure impact, thereby preventing deformation of the sealing surface due to pressure changes and causing leakage. Furthermore, a symmetrically arranged heat-dissipating bonnet structure is used in high-temperature operating conditions to position the packing away from the center of the flow passage. Furthermore, a butterfly spring structure capable of compensating for axial deformation of the valve shaft is used to provide displacement compensation for the valve shaft under high-temperature deformation, thereby improving the phenomenon of the bottom bonnet and valve shaft becoming stuck under high-temperature operating conditions in conventional structures.

[0020] 2. During the expansion deformation compensation process, the heat generated by the upper valve stem and lower valve stem assembly is conducted through the upper heat dissipation valve cover and the lower heat dissipation valve cover, thereby dissipating the heat accumulation of the valve plate and the metal hard sealing structure in the butterfly valve, and reducing the problem of decreased sealing effect of the butterfly valve due to thermal fatigue; when the valve shaft structure as a whole is subjected to high temperature and expansion deformation, the butterfly spring part can be elastically loaded, that is, the upper valve stem and the lower valve stem are axially deformed downward and squeeze the butterfly spring part. After the butterfly spring part is deformed, the valve shaft structure composed of the upper valve stem and the lower valve stem can continue to perform normal opening and closing rotation actions. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0022] Figure 1 It is a structural schematic diagram of the present invention;

[0023] Figure 2 This is a schematic diagram of the valve plate opening of the present invention;

[0024] Figure 3 A bottom view of the valve plate of the present invention with the valve plate opened;

[0025] Figure 4 is a side sectional view of the present invention;

[0026] Figure 5 Schematic diagram of the deformation compensation structure of the present invention;

[0027] Figure 6 A schematic diagram of a cross-sectional structure of the deformation compensation structure of the present invention;

[0028] Figure 7 is a schematic cross-sectional view of the valve body of the present invention;

[0029] Figure 8 It is a split schematic view of the cross-section structure of the valve body and valve plate assembly of the present application.

[0030] Figure 9 It is a schematic view of the fluid passing direction of the present application.

[0031] In the figure: 1, valve seat; 2, fixed sleeve; 3, valve plate; 4, conical locking plate; 5, outer pressure bearing plate; 6, gasket; 7, conical passing surface; 8, gradual contact surface; 9, supplementary sealing surface; 10, locking contact surface; 11, mounting seat; 12, upper heat dissipation valve cover; 13, upper valve stem; 14, lower heat dissipation valve cover; 15, bottom support bracket; 16, lower valve stem; 17, butterfly spring part; 18, upper shaft sleeve; 19, gland; 20, packing; 21, lower shaft sleeve; 22, dustproof ring; 23, gasket; 24, bottom bearing. DETAILED DESCRIPTION

[0032] The technical solutions of the present application will be described clearly and completely below in combination with embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0033] Embodiment one: for the structure improvement of butterfly valve in high temperature working condition, to avoid thermal expansion deformation and have stable sealing performance, the following technical solutions are proposed:

[0034] Referring to Figure 1 - Figure 9 As shown in the figure, the three-eccentric butterfly valve with bidirectional metal hard sealing structure in the embodiment includes a valve seat 1 and a valve plate 3. The valve plate 3 is a concave groove with a poor arc cross-section near the fluid inlet side. The valve seat 1 is symmetrically provided with heat dissipation assemblies at the upper and lower ends. The upper valve stem 13 is rotatably arranged at the upper end of the middle part of the valve seat 1. The lower end of the upper valve stem 13 is provided with a lower valve stem 16 extending to the outside of the valve seat 1.

[0035] Referring to Figure 7 and Figure 8 As shown in the figure, the metal hard sealing structure is stacked on the outer periphery side of the valve plate 3. The metal hard sealing structure is provided with a conical locking plate 4 and an outer pressure bearing plate 5. The valve seat 1 is provided with a conical passing surface 7 corresponding to the fluid passing channel. The outer periphery side of the valve plate 3 is provided with a gradual contact surface 8. The conical locking plate 4 and the outer pressure bearing plate 5 are respectively provided with a supplementary sealing surface 9 and a locking contact surface 10 which are matched with the conical passing surface 7.

[0036] The progressive contact surface 8 is the transition between the valve plate 3 and the tapered passing surface 7 during the rotation process, from progressive line contact to progressive surface contact. Specifically, the contact starts from line contact at the moment the valve plate 3 closes, and gradually expands to full conical surface contact as the valve plate 3 rotates, thereby preventing seal failure caused by sudden fluid impact.

[0037] A turbulent flow port is provided between the supplementary sealing surface 9 and the outer end of the tapered through surface 7 and a centrifugal port is provided between the locking contact surface 10 and the outer end of the supplementary sealing surface 9. Figure 9 The schematic diagram of the flow direction of the fluid passing through the valve plate 3 clearly shows that when the valve plate 3 is closed, the fluid directly impacts the groove on the valve plate 3 and forms an arc-shaped reverse thrust flow. Under the combined action of the circumferential turbulence port and the centrifugal port, the fluid produces a "conical surface extrusion situation" and reversely presses the metal hard sealing structure composed of the conical lock plate 4 and the outer pressure plate 5, thereby forming a "pressure-assisted seal". Under the synchronous action of the two, the butterfly valve achieves double dynamic sealing and ensures that there is no risk of leakage.

[0038] For the entire fluid flow process of the butterfly valve, during the closing process of the valve plate 3, the fluid channel area gradually decreases, the eccentric angle between the valve plate 3 and the upper valve stem 13 causes the conical sealing surface to wedge into the valve seat 1, and the medium pressure pushes the valve plate 3 to press the metal hard sealing structure, forming a "pressure-assisted seal";

[0039] When the valve plate 3 is in the closed state, the triple eccentric structure makes the metal hard seal structure completely out of contact, and only the asymptotic contact surface 8 on the valve plate 3 is in contact with the tapered passing surface 7, thereby reducing the wear of the metal hard seal structure and improving its service life;

[0040] Reference Figure 8 As shown, a sealing gasket 6 is installed between the outer circumference of the valve plate 3 and the conical lock plate 4 , and the outer circumference of the sealing gasket 6 does not exceed the conical annular surface of the conical lock plate 4 .

[0041] In view of the high-temperature working conditions of the butterfly valve, how to quickly disperse the heat in the center of the flow channel is particularly important. For this purpose, a heat dissipation component is added; the upper heat dissipation valve cover 12 and the lower heat dissipation valve cover 14 are symmetrically arranged on both ends of the upper valve stem 13 and the lower valve stem 16 assembly, and the upper heat dissipation valve cover 12 and the lower heat dissipation valve cover 14 are both provided with heat dissipation blades;

[0042] The upper heat dissipation valve cover 12 and the lower heat dissipation valve cover 14 conduct the heat generated by the upper valve stem 13 and the lower valve stem 16 combination, thereby dissipating the heat accumulation of the valve plate 3 and the metal hard sealing structure in the butterfly valve, reducing the problem of decreased sealing effect of the butterfly valve due to thermal fatigue;

[0043] Reference Figure 4 - Figure 6As shown, a bottom support bracket 15 is installed at the lower end of the lower heat dissipation valve cover 14 at the bottom, a bottom bearing 24 for rotating support of the lower valve stem 16 is installed in the bottom support bracket 15, and a butterfly spring member 17 connected to the bottom support bracket 15 is installed at the lower end of the lower valve stem 16;

[0044] In high-temperature operating conditions, the upper valve stem 13 and the lower valve stem 16 of the butterfly valve form a valve shaft structure. Due to high-temperature expansion and deformation, the valve shaft structure will inevitably expand and deform. If no intervention is taken, sealing failure is very likely to occur. For this purpose, a butterfly spring member 17 is added;

[0045] Among them, the purpose of setting the butterfly spring component 17 is: by separating the valve shaft structure into an upper valve stem 13 and a lower valve stem 16, and the lower valve stem 16 completes the support rotation based on the bottom bearing 24 in the bottom support bracket 15, under high temperature conditions, even if the upper valve stem 13 and the lower valve stem 16 produce high-temperature deformation, they can complete elastic displacement under the deformation compensation action of the butterfly spring component 17, thereby improving the conventional integrated valve shaft structure from getting stuck with the bottom cover under high temperature conditions.

[0046] Basic principle: This embodiment improves the triple-eccentric butterfly valve. During the closing process of the valve plate 3, the flow passage area gradually decreases and the fluid pressure gradually increases. A metal static sealing structure is set at the contact point between the valve seat 1 and the valve plate 3 to keep the dynamic sealing part in the valve body stable after being subjected to high-pressure impact, thereby avoiding deformation of the sealing surface due to pressure changes and causing leakage.

[0047] Example 2: Reference Figure 1 - Figure 9 As shown, a mounting seat 11 is mounted on the upper end of the valve seat 1. The mounting seat 11 is filled with a packing 20 near the interior of the valve seat 1. A gland 19 connected to the mounting seat 11 is encapsulated on the packing 20. The packing is designed to be away from the valve seat 1, so that the sealing packing in the butterfly valve is arranged away from the center of the flow channel, thereby providing a heat-proof effect for the rotating sealing pair of the butterfly valve against the valve shaft, thereby avoiding the risk of leakage of the rotating sealing pair under high temperature conditions.

[0048] Reference Figure 4 As shown, an upper shaft sleeve 18 is embedded in the upper end of the valve seat 1, and a lower shaft sleeve 21 is embedded in the interior of the valve seat 1 near the lower heat dissipation valve cover 14. The upper shaft sleeve 18 and the lower shaft sleeve 21 are used together to support the rotation of the upper valve stem 13, and the separate valve shaft structure can be supported by the bottom bearing 24 during the rotation process. The external rotation support can reduce the vibration damage caused by the opening and closing process of the butterfly valve, and further improve the sealing effect of the butterfly valve.

[0049] Reference Figure 5As shown, the lower end of the lower shaft sleeve 21 is provided with a dust ring 22, and the dust ring 22 is connected to the upper end of the lower heat dissipation valve cover 14. The bottom support bracket 15 is installed with a gasket 23 corresponding to the bottom outer side of the butterfly spring member 17. The inner ring side of the gasket 23 is in contact with the bottom outer side of the butterfly spring member 17. In combination with the first embodiment, the deformation compensation process of the butterfly spring member 17 is: when the valve shaft structure as a whole is subjected to high temperature and expansion deformation, it can be elastically loaded by the butterfly spring member 17, that is, the upper valve stem 13 and the lower valve stem 16 are axially deformed downward and squeeze the butterfly spring member 17. After the butterfly spring member 17 is deformed, the valve shaft structure composed of the upper valve stem 13 and the lower valve stem 16 can continue to perform normal opening and closing rotation actions, which has a beneficial effect.

[0050] The implementation principle of this embodiment is: a symmetrically arranged heat dissipation valve cover structure is used in high-temperature working conditions to set the packing away from the center of the flow channel, and the butterfly spring structure in Example 1 that can compensate for the axial deformation of the valve shaft is used to provide displacement compensation of the valve shaft under high-temperature deformation, thereby improving the phenomenon of the bottom valve cover and the valve shaft being stuck in high-temperature working conditions under conventional structures.

[0051] In summary, it can be seen from the combination of Example 1 and Example 2 that an improvement is made to a three-eccentric butterfly valve used in high-temperature working conditions. During the closing process of the valve plate 3, the flow passage area gradually decreases and the fluid pressure gradually increases. A metal static sealing structure is provided at the contact portion between the valve seat 1 and the valve plate 3 to maintain a stable dynamic sealing state even after the sealing portion in the valve body is subjected to a high-pressure impact, thereby avoiding deformation of the sealing surface due to pressure changes, which may lead to leakage.

[0052] In addition, a symmetrically arranged heat dissipating valve cover structure is used in high-temperature working conditions to place the packing away from the center of the flow channel. In combination with a butterfly spring structure that can compensate for the axial deformation of the valve shaft, displacement compensation of the valve shaft under high-temperature deformation is provided, thereby improving the phenomenon of the bottom valve cover and the valve shaft being stuck in high-temperature working conditions under conventional structures.

[0053] The above contents are merely examples and explanations of the structure of the present invention. Those skilled in the art may make various modifications or additions to the described specific embodiments or replace them in a similar manner. As long as they do not deviate from the structure of the invention or exceed the scope defined by the claims, they shall fall within the scope of protection of the present invention.

Claims

1. A three-eccentric butterfly valve with a bidirectional metal hard seal structure comprises a valve seat (1) and a valve plate (3), characterized in that: The valve plate (3) has a groove with a bad arc cross section on the side close to the fluid inlet, and the valve seat (1) has heat dissipation components symmetrically arranged at the upper and lower ends; An upper valve stem (13) is rotatably provided at the upper end of the middle portion of the valve seat (1), and a lower valve stem (16) extending to the outside of the valve seat (1) is installed at the lower end of the upper valve stem (13); a metal hard sealing structure is stacked on the outer peripheral side of the valve plate (3), and a conical lock plate (4) and an outer pressure plate (5) are installed on the metal hard sealing structure; the valve seat (1) is provided with a conical passing surface (7) corresponding to the fluid passing channel, and a progressive contact surface (8) is provided on the outer peripheral side of the valve plate (3); and a supplementary sealing surface (9) and a locking contact surface (10) adapted to the conical passing surface (7) are respectively provided on the outer sides of the conical lock plate (4) and the outer pressure plate (5); A turbulence port is provided between the supplementary sealing surface (9) and the outer end of the tapered passing surface (7), and a centrifugal port is provided between the locking contact surface (10) and the outer end of the supplementary sealing surface (9).

2. The triple eccentric butterfly valve with a bidirectional metal hard seal structure according to claim 1 is characterized in that: The heat dissipation assembly comprises an upper heat dissipation valve cover (12) and a lower heat dissipation valve cover (14), wherein the upper heat dissipation valve cover (12) and the lower heat dissipation valve cover (14) are symmetrically arranged to cover both ends of the upper valve stem (13) and the lower valve stem (16) combination.

3. The triple eccentric butterfly valve with a bidirectional metal hard seal structure according to claim 2 is characterized in that: A bottom support bracket (15) is installed at the lower end of the lower heat dissipation valve cover (14) at the bottom, a bottom bearing (24) for rotationally supporting the lower valve stem (16) is installed in the bottom support bracket (15), and a butterfly spring member (17) connected to the bottom support bracket (15) is installed at the lower end of the lower valve stem (16).

4. The triple eccentric butterfly valve with a bidirectional metal hard seal structure according to claim 1 is characterized in that: A mounting seat (11) is installed at the upper end of the valve seat (1), and a filler (20) is filled inside the mounting seat (11) close to the valve seat (1). A pressure cover (19) connected to the mounting seat (11) is encapsulated on the filler (20).

5. The triple eccentric butterfly valve with a bidirectional metal hard seal structure according to claim 2 is characterized in that: An upper shaft sleeve (18) is embedded in the upper end of the valve seat (1), and a lower shaft sleeve (21) is embedded in the interior of the valve seat (1) close to the lower heat dissipation valve cover (14). The upper shaft sleeve (18) and the lower shaft sleeve (21) are used together to support the rotation of the upper valve stem (13).

6. The triple eccentric butterfly valve with a bidirectional metal hard seal structure according to claim 1 is characterized in that: A sealing gasket (6) is installed between the outer peripheral sides of the valve plate (3) and the conical lock plate (4), and the outer peripheral side of the sealing gasket (6) does not exceed the conical annular surface of the conical lock plate (4).

7. The triple eccentric butterfly valve with a bidirectional metal hard seal structure according to claim 5 is characterized in that: The lower end of the lower shaft sleeve (21) is provided with a dust ring (22), and the dust ring (22) is connected to the upper end of the lower heat dissipation valve cover (14).

8. The triple eccentric butterfly valve with a bidirectional metal hard seal structure according to claim 3 is characterized in that: A washer (23) is installed on the outer side of the bottom of the bottom support bracket (15) corresponding to the butterfly spring component (17), and the inner ring side of the washer (23) is in contact with the outer side of the bottom of the butterfly spring component (17).

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