Ball valve with downstream residue purge

Abstract

A downstream ball valve purge inlet deliberately directs purge fluid onto a downstream portion of the valve ball. The Coanda effect attaches some fluid to the surface of the ball such that it flows around the ball to its opposite side, thereby cleaning the downstream valve cavity more effectively than a design that avoids impacting the ball, and relying on mixing to dispense the cleaning fluid onto the ball. The wash inlet may be downstream of the ball, and directed at an acute angle, near the ball, and perpendicular to the outlet axis, or some combination thereof. The central cavity purge drain may be connected with the purge inlet such that the same fluid purges the valve interior and the downstream cavity. Embodiments include a plurality of downstream purge inlets, which may have equal purge angles and may be equally spaced about an outlet axis.

Description

[0001] Related Applications

[0002] This application claims priority to U.S. Patent Application No. 17 / 984,668, filed on November 10, 2022, the entire contents of which are incorporated herein by reference for all purposes. Technical Field

[0003] The present invention relates to ball valves and, more particularly, to cleaning process fluid residues from ball valves. Background Art

[0004] Ball valves are rugged valves used in many applications, sometimes under extreme operating conditions including high temperatures and high pressures. This is encountered, for example, in the oil industry, and in various other energy-related fields, such as equipment for storing and recovering solar energy by heating and transporting molten salts. In some of these applications, when the ball valve is closed, a residual amount of process fluid (referred to herein as "process residue") is retained within and on the downstream side of the ball valve, where it solidifies when it cools and / or dries. This can result in the need for increased force when the valve is opened again, and can even result in blockage of the valve and / or process lines downstream of the valve. For these reasons, when used under these difficult conditions, safe and reliable operation of the ball valve requires that when the valve is closed, the interior and downstream areas of the ball valve be cleaned of process residues by a well-designed cleaning system.

[0005] refer to Figure 1A Stereoscopic image, Figure 1B and Figure 1C A side cross-sectional view of Figure 1D , ball valve 100 includes a substantially spherical "ball" 102 penetrated by a central passage 104 and rotated by a valve stem 114 within a seat 106, which forms a seal with the ball 102 and is located within and fixed to a valve housing 107, wherein the housing 107 includes a valve inlet 108 and a valve outlet 110. When the valve is open, as shown in FIG. Figure 1B As shown, ball 102 is rotated so that its central passage 104 is aligned with inlet 108 and outlet 110 of valve 100, thereby allowing process fluid to flow from the inlet process line to the outlet process line. Figures 1A to 1C As shown, the inlet 108 and outlet 110 of the valve 100 are located at opposite ends of the valve so that when the valve is open, the process fluid flows through the valve 100 in a substantially continuous "longitudinal" direction 112. In embodiments where the inlet 108 and outlet 110 are not at opposite ends of the valve 100, the term "longitudinal direction" is used herein to refer to the direction in which the process fluid flows through the outlet 110.

[0006] When the valve is closed, Figures 1C to 1DAs shown, the ball 102 is rotated such that the inlet 108 and the outlet 110 are blocked by the side of the ball 102, thereby forming a closed "central cavity" within the valve 100. This central cavity includes the central passage 104 of the ball 102 and the space between the ball 102 and the housing 106. Additionally, the region 116 immediately downstream of the ball becomes a "downstream cavity" that leads to the outlet 110 and the outlet process line, but is bounded on all other sides by the valve seat 106, the exposed section of the valve ball 102, and the walls of the valve outlet 110 and / or the outlet process line. Although the downstream cavity 116 is open to the outlet process line, when the valve 100 is closed, especially when the process fluid is highly viscous and / or when the outlet process line slopes upward as it emerges from the valve outlet, the downstream cavity 116 remains an area where process residues can collect and solidify.

[0007] Accordingly, when the valve 100 is closed, in some applications it is crucial that process residues be removed from within the central passage 104 of the valve ball 102 and from the region 116 immediately downstream of the valve ball as quickly as possible. To this end, some ball valves include a cleaning system configured to direct a cleaning fluid through the central cavity and through the downstream cavity when the ball valve is closed, thereby removing any process residues from the valve. In some cases, the cleaning fluid merely flushes the process residues from the valve, while in other cases the cleaning fluid dissolves the process residues as they are flushed from the valve.

[0008] Referring Figure 1D to the top cross-sectional view, a cleaning system for removing process residues from the central cavity of the ball valve 100 typically includes a central cleaning inlet 118 and a central cleaning drain 120. The cleaning fluid entering through the central cleaning inlet 118 is dispersed throughout the central passage 104 and in the space between the ball 102 and the housing 106 to flush away and / or dissolve the process residues and convey them out through the central cleaning drain 120.

[0009] In addition, the cleaning system includes a downstream cleaning inlet 122. A downstream cleaning drain is not required because the cleaning fluid can be discharged from the downstream cavity through the downstream process line along with the flushed and / or dissolved process residues. In the region 116 surrounding the exposed section of the ball 102, the need to remove process residues from the downstream cavity is greatest. However, the structure of the valve 100 requires that all cleaning ports enter the valve laterally, i.e., from the side of the valve. To this end, continuing to refer Figure 1D to Figure 1E and Figure 1F to the simplified diagrams, the downstream cleaning inlet 122 is typically longitudinally offset downstream of the valve ball 102 such that the cleaning fluid 126 is not blocked by the ball 102 and can freely reach the far side of the downstream cavity. Generally, as Figures 1D to 1FAs shown, the downstream cleaning inlet 122 directs the cleaning fluid laterally such that it only brushes against the longitudinal apex 128 of the valve ball 102.

[0010] This method mainly depends on the turbulent secondary flow 130 of the cleaning fluid 126 to distribute the fluid to the area 116 directly surrounding the ball 102 and adjacent to the junction between the ball 102 and the valve seat 106. Therefore, the cleaning fluid is less effective in flushing and dissolving the process residues, increasing the time and the amount of cleaning fluid required to remove the process residues from the downstream cavity.

[0011] Accordingly, what is needed is a ball valve that can clean process residues from the downstream cavity of the valve with increased speed and effectiveness while requiring less cleaning fluid. Summary of the Invention

[0012] The present invention is a ball valve that can remove process residues from the downstream cavity of the valve with increased speed and effectiveness while requiring less cleaning fluid. The downstream cleaning inlet is positioned and directed such that the cleaning fluid intentionally impacts the ball, rather than being positioned and directed such that the cleaning fluid avoids impacting the ball.

[0013] The present invention has been realized by the inventors: If the cleaning fluid flow impacts the ball, the cleaning fluid flow will not be blocked and reach the far side of the ball, but will be guided around the ball such that the cleaning fluid flow reaches most of the surfaces of the ball and the adjacent valve seat as a direct flow. This is because, when impacting the ball, due to the Coanda effect, at least some of the cleaning fluid attaches to the surface of the ball, causing it to follow the curve of the ball to reach the far side of the cavity.

[0014] According to the Coanda effect, a fluid emerging from a nozzle and flowing adjacent and parallel to a surface will tend to become attached to the surface such that even if the surface is convexly curved, the fluid will follow the surface. The present invention causes the cleaning fluid to emerge from the downstream cleaning inlet acting as a nozzle and impact the ball in a direction coplanar with the central axis of the valve outlet. When the fluid flow impacts the ball, some of the fluid at the outer perimeter of the flow is reflected away from the ball, while the remaining fluid divides into two flows that continue to follow the convex surfaces on either side of the ball. This is because the inner region of the fluid flow is constrained by the outer region of the flow to remain close to the surface of the ball and thereby attach to the ball by the Coanda effect.

[0015] The reflected portion of the cleaning fluid stream impacts a portion of the valve seat closer to the inlet wall and other areas within the downstream cavity, while the remaining fluid continues along the surface of the ball and effectively washes away and / or dissolves any process residues that have deposited on or near the ball. And when these two attached streams converge on the distal side of the ball, they collide and are deflected away from the ball into the surrounding space "behind" the ball, i.e., into the area adjacent to the ball, which is directly opposite the location of the downstream cleaning inlet.

[0016] In some embodiments, the cleaning angle (i.e., the angle between the longitudinal axis of the valve (process flow direction) and the direction of the cleaning fluid flow) is 90 degrees, and the location of the downstream cleaning inlet is axially displaced such that the stream of cleaning fluid impacts the ball. In other embodiments, the cleaning angle is an acute angle, thereby enabling the downstream cleaning inlet to be axially positioned further away from the ball, e.g., in the same location where a conventional vertical cleaning inlet might otherwise be positioned. In different embodiments, the cleaning angle is between 30 degrees and 90 degrees, in some of these embodiments between 60 degrees and 90 degrees, and in some of these embodiments between 80 degrees and 90 degrees.

[0017] The embodiments further include a central cleaning inlet and a central cleaning drain that are capable of cleaning the central cavity of the ball valve. In some of these embodiments, the central cleaning drain is connected to the downstream cleaning inlet such that the same cleaning fluid can flow through the central cavity and then into the downstream cavity.

[0018] The present invention is a ball valve configured to control the flow of process fluid therethrough. The ball valve includes: a valve housing having a valve inlet and a valve outlet, the valve outlet surrounding the longitudinal axis of the valve housing; a valve seat within the valve housing and fixed to the valve housing; a ball element rotatable within the valve seat and forming a seal with the valve seat, the ball element being penetrated by a central passage that is aligned with the valve inlet and the valve outlet, and when the ball element is rotated to the open position, the central passage forms a fluid interconnection between the valve inlet and the valve outlet, and when the ball element is rotated to the closed position, the valve inlet is isolated from the valve outlet, and a downstream cleaning inlet is configured to direct a cleaning fluid stream onto the downstream portion of the ball element in the direction of the cleaning inlet when the ball element is in the closed position, the direction of the cleaning inlet being coplanar with the longitudinal axis.

[0019] When the ball is in the closed position, the downstream portion of the ball extends downstream from the valve seat to a vertex that is longitudinally offset from the valve seat by an intrusion distance, and the downstream cleaning inlet directs the cleaning fluid stream onto an impact position on the downstream portion of the ball element that is longitudinally offset downstream from the valve seat by an impact distance, and the ratio of the impact distance to the intrusion distance is less than 0.9.

[0020] In an embodiment, the angle between the longitudinal axis and the cleaning inlet direction is between 30 degrees and 90 degrees.

[0021] In any of the above embodiments, the angle between the longitudinal axis and the cleaning inlet direction can be between 60 degrees and 90 degrees.

[0022] In any of the above embodiments, the angle between the longitudinal axis and the cleaning inlet direction can be between 80 degrees and 90 degrees.

[0023] Any of the above embodiments may further include a central cleaning inlet and a central cleaning drain pipe, which are in fluid communication with the central passage of the ball element when the ball element is in the closed position and isolated from the central passage of the ball element when the ball element is in the open position. In some of these embodiments, the central cleaning drain pipe is in fluid communication with the downstream cleaning inlet.

[0024] In any of the above embodiments, the ratio of the impact distance to the intrusion distance can be less than 0.9.

[0025] In any of the above embodiments, the ratio of the impact distance to the intrusion distance can be less than 0.8.

[0026] In any of the above embodiments, the ratio of the impact distance to the intrusion distance can be between 0.4 and 0.6.

[0027] In any of the above embodiments, the downstream cleaning inlet can be the first downstream cleaning inlet included in a plurality of downstream cleaning inlets, all of which are configured to direct the cleaning fluid to a corresponding impact position on the downstream portion of the ball element when the ball element is in the closed position. In some of these embodiments, all the impact positions are longitudinally offset from the valve seat by the same impact distance downstream. In any of these embodiments, the downstream cleaning inlets can be circumferentially spaced apart around the longitudinal axis. And in any of these embodiments, the downstream cleaning inlets can be circumferentially equally spaced apart around the longitudinal axis.

[0028] These features and advantages described herein are not all-inclusive, and in particular, given the drawings, the specification, and the claims, many additional features and advantages will be apparent to those of ordinary skill in the art. Additionally, it should be noted that the language used in this specification has been selected primarily for readability and guidance purposes and not to limit the scope of the subject matter of the invention. Description of the Drawings

[0029] Figure 1A is a side perspective view of a prior art ball valve;

[0030] Figure 1B is Figure 1A A side cross-sectional view of a valve, showing the valve open;

[0031] Figure 1C is Figure 1A A side cross-sectional view of a valve, showing the valve closed;

[0032] Figure 1D is Figure 1C A top cross-sectional view of a valve;

[0033] Figure 1E A simplified top cross-sectional view of the downstream region of a prior art ball valve;

[0034] Figure 1F shows Figure 1E a valve, showing the situation when a cleaning fluid is injected into the downstream cleaning port;

[0035] Figure 2A A top view of a ball valve in an embodiment of the present invention;

[0036] Figure 2B is a top cross-sectional view showing a ball valve of Figure 2A in a closed configuration;

[0037] Figure 3A A simplified top cross-sectional view of the downstream region of a ball valve in an embodiment of the present invention, where the cleaning angle is an acute angle;

[0038] Figure 3B is similar to Figure 3A a simplified cross-sectional view, where the cleaning angle, intrusion distance, and impact distance are graphically indicated;

[0039] Figure 4 A simplified end cross-sectional view showing the flow of cleaning fluid through the downstream portion of the ball of a ball valve according to an embodiment of the present invention;

[0040] Figure 5 A simplified top cross-sectional view of the downstream region of a ball valve in an embodiment of the present invention, where the cleaning angle is a right angle;

[0041] Figure 6A A perspective view of an embodiment of the present invention, where a central cleaning drain pipe is connected to a downstream cleaning inlet;

[0042] Figure 6B A top view of an embodiment of the present invention including a plurality of downstream cleaning inlets;

[0043] Figure 7A shows the results of simulating the downstream cleaning fluid flow of a prior art ball valve; and

[0044] Figure 7B Shows the results of simulating the downstream cleaning fluid flow of the ball valve in an embodiment of the present invention. Detailed Description

[0045] The present invention is a ball valve that can remove process residues from the downstream cavity of the valve at increased speed and effectiveness while requiring less cleaning fluid.

[0046] Reference Figure 2A top view of Figure 2B top cross-sectional view of Figure 3A and Figure 3B simplified illustrations of

[0047] The present invention causes the cleaning fluid to emerge from the downstream cleaning inlet 200 acting as a nozzle and impinge on the ball 102 in a direction coplanar with the central axis 112 of the valve outlet. Referring to Figure 4 when the fluid flow 400 impinges on the ball 102, some of the fluid at the outer periphery of the flow 402 is reflected away from the ball 102, while the remaining fluid 404 is split into two flows that continue to follow the convex surfaces on either side of the ball 102. This is because the inner region 404 of the fluid flow 400 is constrained by the outer region 402 of the flow 400 to remain close to the surface of the ball 102 and thus attaches to the ball 102 by the Coandă effect.

[0048] The reflected portion 402 of the cleaning fluid flow 400 impinges on the nearer portion of the valve seat 106, the inlet wall, and other areas within the downstream cavity 116, while the remaining fluid 404 continues along the surface of the ball 102 and effectively washes away and / or dissolves any process residues that have been deposited on or near the ball 102. And when the two attached flows 404 converge on the far side of the ball 102, they collide with each other to form an outwardly deflected fluid flow 406 that is driven away from the ball 102 and into the surrounding space "behind" the ball, i.e., into the region adjacent to the ball 102 that is directly opposite the position of the downstream cleaning inlet 200.

[0049] Referring again to Figure 3B the cleaning fluid flow 300 impinges on the ball 102 at a location 310 that lies on a curve 314 that lies in the plane of the longitudinal axis 112 of the valve outlet 110 and extends between the apex 128 of the ball and the junction 304 where the ball 102 emerges from the seat 106. In Figure 3BA vertical line 306 is shown, which extends perpendicular to the longitudinal axis 112 of the valve outlet 110 from the junction 304 and in its plane. The intrusion distance 308 is thus defined as the distance between this line 306 and the apex 308 of the ball 102, which is the distance that the ball 102 extends beyond the seat 106 into the outlet 110. The cleaning fluid flow 300 impinges on the ball 102 at point 310 on the curve 314, and the offset of point 310 from the dashed line 306 is the impingement offset 312, which is less than the intrusion distance 308. In embodiments, the ratio of the impingement offset 312 to the intrusion distance 308 is less than 0.9, and in some of these embodiments, it is less than 0.8. In different embodiments, this ratio is between 0.4 and 0.6.

[0050] In Figures 2A to 3B embodiments, the cleaning angle (i.e., the angle θ between the longitudinal axis 112 of the valve outlet 110 (process flow direction) and the cleaning fluid flow direction 300) is an acute angle, such that the downstream cleaning inlet 200 can be axially offset from the ball 102, e.g., in the same position where a conventional vertical cleaning inlet 122 might otherwise be located.

[0051] Referring to Figure 5 , in other embodiments, the cleaning angle θ is 90 degrees, and the position of the downstream cleaning inlet 200 is axially shifted closer to the ball 102 such that the flow of the cleaning fluid 400 impinges on the ball 102. In different embodiments, the cleaning angle θ is between 30 degrees and 90 degrees, in some of these embodiments, the cleaning angle θ is between 60 degrees and 90 degrees, and in some of these embodiments, the cleaning angle θ is between 80 degrees and 90 degrees.

[0052] Referring again to Figure 2B , embodiments further include a central cleaning inlet 118 that can clean the central cavity of the ball valve. Referring to Figure 6A , in some of these embodiments, the central cleaning drain pipe 120 is connected 202 to the downstream cleaning inlet 200 such that the same cleaning fluid can flow through the central cavity 104 and then into the downstream cavity 116.

[0053] Referring to Figure 6B the top view of

[0054] Referring to Figure 7A and Figure 7B, simulations were performed to compare several flow and geometric parameters of the embodiments of the present invention with corresponding examples of the prior art. It was found that if the cleaning fluid is directed to the impact location on the ball 102 between the seat 106 and the ball 102, the process fluid residues can be removed more effectively compared to the prior art. In addition, it can be seen that the flow of the cleaning fluid close to the surface of the ball 102 is more uniform, and the size of the recirculation zone is reduced.

[0055] Several different scenarios with different cleaning pressures and geometries were studied by using computational fluid dynamics (CFD) simulations with ANSYS FLUENT.

[0056] For purposes of illustration and description, the foregoing description of the embodiments of the present invention has been presented. Every page of this submission and all of the content thereon (however characterized, identified, or numbered) is considered to be a substantial part of this application for all purposes, regardless of the form or placement within the application. This specification is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of this disclosure.

[0057] Although this application is shown in a limited number of forms, the scope of the present invention is not limited to these forms, but is subject to various changes and modifications. The disclosure presented herein does not explicitly disclose all possible combinations of features that fall within the scope of the present invention. Without departing from the scope of the present invention, the features disclosed herein for various embodiments can generally be interchanged and combined into any combination that is not self-contradictory. Specifically, unless the dependent claims are logically incompatible with each other, the limitations given in the following dependent claims can be combined with their corresponding independent claims in any number and in any order without departing from the scope of this disclosure.

Claims

1. A ball valve configured to control the flow of process fluid therethrough, the ball valve comprising: A valve housing having a valve inlet and a valve outlet, the valve outlet surrounding a longitudinal axis of the valve housing, and a valve seat located within the valve housing and fixed to the valve housing; A ball element rotatable within the valve seat and forming a seal therewith, the ball element being penetrated by a central passage that aligns with the valve inlet and the valve outlet, and when the ball element rotates to an open position, the central passage forms a fluid interconnection between the valve outlet and the valve inlet, and when the ball element rotates to a closed position, the valve inlet is isolated from the valve outlet; And A downstream cleaning inlet configured to direct cleaning fluid onto a downstream portion of the ball element in a cleaning inlet direction when the ball element is in the closed position, the cleaning inlet direction being coplanar with the longitudinal axis; Wherein, when the ball is in the closed position: The downstream portion of the ball extends downstream from the valve seat to a vertex that is longitudinally offset from the valve seat by an intrusion distance; and The downstream cleaning inlet directs a flow of cleaning fluid onto an impact location on the downstream portion of the ball element, the impact location being longitudinally offset downstream from the valve seat by an impact distance; The ratio of the impact distance to the intrusion distance is less than 0.

9.

2. The ball valve according to claim 1, wherein The angle between the longitudinal axis and the cleaning inlet direction is between 30 degrees and 90 degrees.

3. The ball valve according to any one of the preceding claims, wherein, The angle between the longitudinal axis and the cleaning inlet direction is between 60 degrees and 90 degrees.

4. The ball valve according to any one of the preceding claims, wherein, The angle between the longitudinal axis and the cleaning inlet direction is between 80 degrees and 90 degrees.

5. The ball valve according to any one of the preceding claims, the ball valve further comprising a central cleaning inlet and a central cleaning drain pipe that are in fluid communication with the central passage of the ball element when the ball element is in the closed position and are isolated from the central passage of the ball element when the ball element is in the open position.

6. The ball valve according to claim 5, wherein, The central cleaning drain pipe is in fluid communication with the downstream cleaning inlet.

7. The ball valve according to any one of the preceding claims, wherein, The ratio of the impact distance to the intrusion distance is less than 0.

9.

8. The ball valve according to any one of the preceding claims, wherein The ratio of the impact distance to the intrusion distance is less than 0.

8.

9. The ball valve according to any one of the preceding claims, wherein, The ratio of the impact distance to the intrusion distance is between 0.4 and 0.

6.

10. The ball valve according to any one of the preceding claims, wherein, The downstream cleaning inlet is a first downstream cleaning inlet included in a plurality of downstream cleaning inlets, all of the downstream cleaning inlets being configured to direct cleaning fluid onto corresponding impact locations on the downstream portion of the ball element when the ball element is in the closed position.

11. The ball valve according to claim 10, wherein, All of the impact locations are longitudinally offset downstream from the valve seat by the same impact distance.

12. The ball valve according to claim 10 or 11, wherein, The downstream cleaning inlets are circumferentially spaced about the longitudinal axis.

13. The ball valve according to any one of claims 10 to 12, wherein, The downstream cleaning inlets are circumferentially equidistantly spaced about the longitudinal axis.

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