Valve and method for cleaning

Abstract

The present invention relates to a valve (1) having: a housing (2) defining an internal space (6); a first connector (3); a second connector (4); a passage (7) connecting the first connector (3) and the second connector (4) in a flow-conducting manner; a first closing element (8) and a second closing element (9) housed in the internal space (6) and surrounding an intermediate space (12) connected to a third connector (5); and an adjusting device (20) configured to, in a closed position, bring the first closing element (8) into sealing contact with a first valve seat (10) formed in the passage (7) and to bring the second closing element (9) into sealing contact with a second valve seat (11) formed in the passage, and in an open position, disengage the first and second closing elements (8, 9) from the first and second valve seats (10, 11), the first closing element (8) being sealedly housed in the second closing element (9). To achieve improved cleaning of the valve, the adjusting device (20) is configured to form a gap (S) between the first and second closing elements (8, 9) connecting the intermediate space (12) and the internal space (6), while simultaneously disengaging the first and second closing elements (8, 9) from the first and second valve seats (10, 11). Furthermore, the invention also relates to a cleaning method.

Description

Technical Field

[0001] The present invention relates to a valve and a method for cleaning. Background Technology

[0002] Valves of this type are used in equipment used to manufacture food, beverages, pharmaceuticals, and fine chemical products, as well as in biotechnology.

[0003] These applications require the valve to have a hygienic design. In particular, it must be able to be thoroughly cleaned.

[0004] One type of valve is known by the name double-seat valve, in which two closing elements are made to seal against their respective mating seats. A so-called leakage space exists between these closing elements. It is now necessary to reliably clean the valve seats. This is the case in double-seat valves with cleanable seats. The double-seat valve is configured such that one closing element is lifted from its mating seat, while the other closing element remains in sealing contact. Cleaning fluid flows through the exposed seat and cleans both the seat and the closing element. The fluid can be drained through the leakage space.

[0005] Such cleanable double-seat valves are known in the prior art.

[0006] WO 2009 / 115255 A1 and EP 0 646 741 B1 describe a double-seat valve with a cleanable seat, in which the seal on the valve stem is also exposed during the cleaning step for cleaning. Both documents illustrate this arrangement, with EP 0 646 741 B1 additionally showing the cleaning of the drive-side seal, which is designed to slide on a closing element section. An earlier document, DE 41 18 874 A1, also illustrates the cleaning of the drive-side seal.

[0007] In EP 0 646 741 B1, the clean position of the seal is associated with the clean position of the main seal on the valve seat. Therefore, the actuator operating with a pressure medium is designed such that it performs a partial stroke in addition to the full stroke or the main stroke. DE 41 18 874 A1 and WO 2009 / 115255 A1 do not provide detailed specifications for the actuator.

[0008] A cleanable double-seat valve can be designed as a so-called tank bottom valve, allowing the tank outlet to be connected to the piping system via an on / off mechanism. WO 2019 / 020361 A1 describes such a tank bottom valve. Summary of the Invention

[0009] The present invention aims to improve the cleanability of valves and to provide a cleaning method.

[0010] The objective is achieved by the valve according to the invention and the method according to the invention.

[0011] According to the present invention, a valve is provided, comprising: a housing defining an internal space; a first connector; a second connector; a passage connecting the first connector and the second connector in a flow-conducting manner; a first closing element and a second closing element, the closing elements being housed in the internal space and surrounding an intermediate space connected to a third connector; and an adjusting device configured to, in a closed position, seal the first closing element against a first valve seat formed in the passage and seal the second closing element against a second valve seat formed in the passage, and in an open position, disengage the first and second closing elements from the first and second valve seats, the first closing element being sealedly housed in the second closing element, wherein the second closing element is cup-shaped, the intermediate space is located inside the second closing element, and the first closing element is accommodating in the second closing element such that the intermediate space is sealed relative to the internal space, and the adjusting device is configured to, when the first and second closing elements are simultaneously lifted from the first and second valve seats, form a gap connecting the intermediate space to the internal space between the first and second closing elements.

[0012] This invention is based on the understanding that, technically, it not only provides known cleaning positions for cleaning valves, but also, contrary to the thinking of the prior art, allows cleaning of components that are currently inaccessible in the open position of the valve. Therefore, it is proposed to open the intermediate space surrounded by the first and second closing elements towards the internal space of the valve. This intermediate space, also called the leakage space, is used to drain leaks and make leaks visible, which may occur due to wear of seals on the closing elements. The opening of the intermediate space towards the internal space is achieved through a gap between the first and second closing elements. Therefore, the adjusting device for adjusting the closing elements is configured to additionally create a gap between these closing elements when they are simultaneously lifted from their respective mating valve seats. This provides a powerful cleaning flow that achieves cleaning of the intermediate space and the closing elements with unprecedented quality. This is particularly advantageous in so-called bottom valves, where low pressure of the cleaning fluid is often observed, which enters through the valve's connection to the tank.

[0013] In the first improved embodiment, the adjusting device includes a structural component that cooperates with one of the closing elements and adjusts the other closing element relative to it in the open position, forming the gap. The additional structural component specifically designed for this function in the adjusting device allows for the best possible realization of this novel clean position. The adjusting device can be adjusted via the structural component to provide the best possible control over the closing element, particularly regarding the gap width. The force used for switching can also be optimized. The operating principle of the structural component is conceivable, for example, based on electromagnetic, hydraulic, or pneumatic principles used in the prior art.

[0014] According to an improved embodiment, the structural component is provided with a piston that can be loaded with a pressure medium, such as air, and according to the invention, when the pressure medium is loaded, the piston achieves additional positions through displacement.

[0015] In an economical and reliable implementation, the piston engages with a boss on one of the valve stems of the closing element. When pressure is applied, the piston engages with the boss, thereby actuating the valve stem as the piston moves.

[0016] The adjustment device can advantageously be modularly designed to adjust the closing element, having at least two drive modules, one of which is designed to achieve an additional cleaning position. This is economical in manufacturing and further allows for adjustments at the customer's location, i.e., within the production process equipment. The drive modules are preferably detachably engageable relative to each other and arranged in rows.

[0017] In the construction of a regulating device consisting of a drive module, it is advantageous that the structural components are housed within a separate drive module. This design is preferably chosen so that the drive module can be retrofitted and integrated into the regulating device. For this purpose, the regulating device may include a section of the valve stem itself, which can be coupled to the valve stem and other drive modules.

[0018] The advantages of modularity can be enhanced if the regulating device includes a drive module that manipulates a closing element to move the closing element to a position corresponding to the open position of the valve.

[0019] If the drive module, including the structural components, is positioned between the housing and the drive module forming the open position, a simple and economical design for the drive module can be achieved. This eliminates the need to modify the drive module whose current position is known for the open position.

[0020] If at least one valve stem, preferably all valve stems, is constructed in a multi-part configuration, the advantages of modularity are enhanced and economically realized, particularly enabling easy retrofitting. The multi-part configuration facilitates modularity. This is the case, for example, when the portions of the valve stem extend only onto their respective drive modules.

[0021] The present invention also relates to a method for cleaning a valve having an intermediate space defined by a first closing element and a second closing element relative to an internal space, and the valve having a first valve seat assigned to the first closing element and a second valve seat assigned to the second closing element, wherein in the closed position of the valve the first closing element is in sealing contact with the first valve seat and the second closing element is in sealing contact with the second valve seat, wherein the second closing element is cup-shaped, the intermediate space is located inside the second closing element, and the first closing element is accommodating within the second closing element such that the intermediate space is sealed relative to the internal space, the first closing element is moved to a position raised from the first valve seat, and the second closing element is moved to a position raised from the second valve seat, and simultaneously a gap is formed between the first closing element and the second closing element, the gap connecting the intermediate space to the internal space.

[0022] According to the method of the invention, two shut-off elements are raised from their mating valve seats, simultaneously creating a gap between the shut-off elements that connects the intermediate space to the internal space. In this way, the cleaning method is extended to a position where cleaning agent can enter the valve, thus achieving thorough cleaning. Attached Figure Description

[0023] The present invention will be described in detail with reference to the embodiments and their improvements. Furthermore, the advantages described herein will be discussed in detail.

[0024] in:

[0025] Figure 1 The double-seat valve in the open position is shown in a tank bottom configuration.

[0026] Figure 2 A partial view shows a double-seat valve with an additional cleaning position according to an embodiment;

[0027] Figure 3 A regulating device for a double-seat valve according to an embodiment is shown. Detailed Implementation

[0028] exist Figure 1 The figure shows a longitudinal sectional view of valve 1, which can be connected to the tank and is cleanable.

[0029] Valve 1 includes a one-piece or multi-piece housing 2 with a first connector 3, which can be connected to a tank or container (not shown). This can be achieved by clamping flanges or welding connections. A second connector 4 is formed on the housing 2 for connection to piping of process equipment. A third connector 5 is provided and can be connected to a device for leak indication and / or leak drainage. The housing defines an internal space 6 that interconnects the first and second connectors 3 and 4 in a flow-directing manner. A passage 7 is formed in the housing between the first and second connectors 3 and 4.

[0030] The first closing element 8 and the second closing element 9 are located in the internal space.

[0031] The first shut-off element 8 engages with the first valve seat 10, which forms a cylindrical surface in the passage 7. Preferably, the second valve seat 11, which is constructed in a stepped shape, is formed on the side of the first valve seat 10 facing the internal space 6. This stepped second valve seat 11 forms an axial stop that limits the movement of the second shut-off element 9.

[0032] The second shut-off element 9 is cup-shaped. An intermediate space 12 exists within the second shut-off element. The first shut-off element 8 is accommodated within the second shut-off element 9 such that the intermediate space 12 is sealed relative to the internal space 6. A channel 13 is formed in the second shut-off element 9 on the side opposite to the first shut-off element 8 and provides fluid communication between the intermediate space 12 and the third connector 5. Cleaning fluid or leakage through an unsealed location between the valve seat and the shut-off element first enters the intermediate space 12 and reaches the third connector 5 through the channel 13.

[0033] The closing elements 8 and 9 can be moved by means of the adjusting device 20.

[0034] The regulating device 20 is advantageously modularly configured and has multiple drive modules, which in this example are designed to operate under pressure and are partially spring-loaded.

[0035] The first valve stem 21 is connected to the first closing element 8, and the first valve stem is movably disposed within the second valve stem 22, which is designed as a hollow stem. The second valve stem 22 is connected to the second closing element 9.

[0036] The regulating device 20 includes a first drive module 23, in which a first piston 24 is disposed. The first piston cooperates with a first valve stem 21. The first drive module 23 allows a first closing element 8 to reciprocate between two positions. In the first position, the first closing element 8 is in sealing contact with the first valve seat 10. In the second position, the closing element 8 is in a retracted position within the internal space 6 after moving along the direction of the regulating device 20. This movement actuates a second closing element 9, and then the valve 1 is in an open position, in which a flow connection exists between the first and second connectors 3 and 4.

[0037] The regulating device 20 includes a second drive module 25, which is detachably connected to the first drive module 23. A second piston 26, cooperating with the first valve stem 21, is disposed within the second drive module. When this piston is loaded with a pressure medium, the second piston 26 applies force to the first valve stem 21, causing the first valve stem 21 to move towards the first connector 3. This causes the first closing element 8, connected to the first valve stem 21, to lift from the first valve seat 10 toward the side of the first valve seat 10 opposite to the internal space 6. This position allows for cleaning, particularly of the first valve seat 10. During this period, the second closing element 9 is in sealing contact with its mating second valve seat 11. The cleaning fluid then flows through the intermediate space 12, then through the channel 13, and exits the valve through the third connector 5.

[0038] A third piston 27 is disposed in the second drive module 25. The third piston cooperates with the second valve stem 22. The third piston 27 and the second valve stem 22 are configured such that when pressure is applied to the third piston 27, the second closing element 9 is lifted from the second valve seat 11 toward the internal space 6. The first closing element 8 remains in sealing contact with the first valve seat 10. This position of the closing elements 8 and 9 allows for cleaning, particularly of the second valve seat 11. Here, cleaning fluid is also discharged through the intermediate space 12, the channel 13, and the third connector 5.

[0039] The regulating device 20 includes a third drive module 28, which is detachably connected to the second drive module 25 and has a fourth piston 29. To create an additional cleaning position, a pressurized medium can be applied to the fourth piston when the first piston 24 has already been pressurized. However, the first piston 24 can be pressurized without manipulating the fourth piston 29. By applying a pressurized medium to the first piston 24, the first and second shut-off elements 8 and 9 are lifted from the first and second valve seats 10 and 11 and moved into the internal space 6. When pressure is applied, the fourth piston 29 engages with the second valve stem 22 and moves the second valve stem, thereby indirectly moving the second shut-off element 9 toward the regulating device 20. This creates a gap between the first and second shut-off elements 8 and 9, allowing cleaning agent to enter the intermediate space 12 from the internal space 6. This provides a particularly powerful cleaning flow, ensuring that all product-contacting surfaces of the valve 1, including the internal space 6 and the intermediate space 12, are thoroughly cleaned in this position of the first and second shut-off elements 8 and 9. Therefore, the valve 1 exhibits significantly superior hygienic properties compared to prior art valves.

[0040] The modular construction of the regulating device 20 with three drive modules 23, 25, and 28 presented in this example allows for economical adaptation of the valve system to customer requirements. In particular, an additional cleaning position can be added to the third drive module 28 on existing equipment and its valves.

[0041] Valve 1 may additionally include a nozzle 30 disposed in the second shut-off element 9 and surrounding the first valve stem 21 when the first valve stem extends from the second valve stem 22. Cleaning fluid can be applied to the nozzle 30 through the gap between the first valve stem 21 and the second valve stem 22.

[0042] Applying appropriate pressure to pistons 24, 26, 27, and 29 can advantageously be achieved by equipping a pressure regulating valve control head 31, which is mounted on valve 1. The pressure regulating valve switches as required, the requirement being sent by the device controller to the electronics of the control head 31. The control head 31 may include a measuring device that determines the position of a measuring target 32 ​​disposed on the first valve stem 21. The positions of the first and second closing elements 8 and 9 can then be determined. This information can be transmitted to the device controller.

[0043] exist Figure 2 In the diagram, the additional cleaning position of valve 1 is shown in detail. The first shut-off element 8 and the second shut-off element 9 retract into the internal space 6 and release the passage 7, so that fluid can flow between the first connector 3 and the second connector 4.

[0044] In the closed position of valve 1, the first valve seat 10, which is in sealing contact with the first seal 81 disposed on the first shut-off element 8, is exposed in this position of valve 1. Similarly, in the closed position of valve 1, the second valve seat 11, which is in sealing contact with the second seal 91 disposed on the second shut-off element, is also exposed. The first seal 81 can advantageously be designed as a radial seal, while the second seal 91 can be designed as an axial seal. In particular, the radial design of the first seal 81 allows the first shut-off element 8 to move through the passage 7 into the first connector 3 and into the second shut-off element 9.

[0045] In the normally open position of valve 1, the first and second closing elements 8 and 9 are also retracted into the internal space 6 and the passage 7 is open, meaning that the passage 7 is permeable to fluid. However, in the open position, the first seal 81 is in sealing contact with the inner seat 92 disposed on the second closing element 9. The inner seat is designed such that the internal space 6 and the intermediate space 12 are fluidically separated from each other in the second closing element 9.

[0046] But Figure 2 In the position shown, the first closing element 8 and the second closing element 9 are moved relative to each other such that, although the passage 7 is open, the first seal 81 is not in sealing contact with the inner seat 92. A gap S is formed between the first and second closing elements 8 and 9, which allows fluid flow. The gap width dimension can advantageously be designed such that the flow established through the gap S achieves cleaning of the first seal 81 and the inner seat 92, as well as cleaning of the surfaces of the first and second closing elements 8 and 9 that are adjacent to the seal and the inner seat. Advantageously, in order to achieve according to Figure 2 The second closing element 9 is positioned towards the adjusting device 20. Figure 2 The element moves downwards and away from passage 7, thereby exposing the second closing element. This improves the cleaning effect.

[0047] The structure of the regulating device 20 in this example is as follows: Figure 3 It is shown in detail in the text.

[0048] The first drive module 23, which brings valve 1 into the open position by moving first and second closing elements 8 and 9 into the internal space 6, includes a first piston 24. The first piston 24 is fixed to a drive rod 231, such that movement of the first piston 24 causes movement of the drive rod 231. Movement of the first piston 24 can be achieved by applying a pressure medium. By applying a pressure medium, such as pressurized air, the first piston 24 moves against the force of a spring 232 or a spring assembly. Movement of the first piston 24 occurs through sliding contact with a first working surface 233, which may be shaped as a cylindrical surface. The movement is defined by a first stop 24. The first stop 24 may be designed as a surrounding protrusion, which may be designed as an annular member.

[0049] The second drive module 25 is disposed on the side of the first drive module 23 facing the closing elements 8 and 9 and the housing 2 and is connected to the housing. This connection is advantageously designed to be releasable, thereby making the second drive module 25 a separate commercial unit.

[0050] A second piston 26 is movably disposed in the second drive module 25. This movement occurs in sliding contact with the second working surface 251. Similarly, a third piston 27 is also movably disposed in the second drive module 25, the third piston being in sliding contact with the third working surface 252. Both pistons 26 and 27 can be loaded with a pressure medium to achieve movement. The pressure loading of pistons 26 and 27 achieves movement in the direction of the corresponding other piston. A second stop 253 is provided between pistons 26 and 27 and the working surfaces 251 and 252. The second stop is designed as an annular member and forms a protrusion for each cylindrical working surface 251 and 252. In this way, a single component forms a movement restriction structure for the two pistons 26 and 27.

[0051] The second drive module 24 is configured to move one of the closing elements 8 and 9 into a cleaning position, in which one of the closing elements is lifted from its mating valve seats 10 and 11, while the corresponding other closing element 8 and 9 remains in sealing contact. For this purpose, the second working surface 251 and the second stop 253 are sized such that the adjustment stroke of the second piston 26 is longer than that of the first piston 24. The drive rod 231 is movably housed in a sliding bushing 254 disposed in the hub 255 of the second piston 26. Adjusting the first piston 24 brings the first closing element 8 into contact with the first valve seat 10. This actuates the second piston 26. Applying pressure to the second piston 26 now moves it to the second stop 253 and pushes the first closing element from the first valve seat 10 into the first connector 3 via the second valve stem 22. At this point, the drive rod 231 is pulled out of the sliding bushing 254.

[0052] The cleaning position of the second shut-off element 9 is achieved by the third piston 27, which is pressurized by applying a pressure medium and thus moving towards the second piston 26. At this time, the third piston 27, movably mounted on the second valve stem 22 in a sliding contact manner, contacts the fourth stop 257, which is formed on the end 256 of the second valve stem. This drives the second valve stem 22 until the third piston 27 reaches the second stop 253. This movement of the second valve stem 22, triggered in this way, lifts the second shut-off element 9 from the second valve seat 11.

[0053] In the third drive module 28, a fourth piston 29 is movably mounted on the second valve stem 22 and configured to engage with a fourth working surface 281 provided on the housing. A boss 282 is formed on the second valve stem 22, which serves as a stop for the fourth piston 29. When a pressurized medium is applied to the fourth piston 29, the fourth piston moves toward the other drive modules 24 and 25 until it reaches the stroke limiting structure 283 on the housing side. Before reaching the stroke limiting structure 283, the fourth piston 29 engages with the boss 282 and thereby drives the second valve stem 22. Thus, in the open position of valve 1, as in Figure 2 As shown, the closing elements 8 and 9 move separately from each other until the desired gap S has been established.

[0054] If at least one, preferably both, of the valve stems 21 and 22 is constructed in a multi-part configuration, the modularity of this construction is improved, with the stem segments preferably assigned to the respective modules 23, 25, and 28.

[0055] This modular construction of the regulating device 20 is advantageous because individual functions, such as cleaning positions for each shut-off element, can be introduced retroactively by adding a second drive module 25. Additional cleaning positions can also be added, implemented by a third drive module 28. In this way, production costs can be reduced, and customer needs can be specifically met through a customized regulating device 20.

[0056] This invention is described using a bottom valve as an example, but it can also be applied to valves according to WO 2009 / 115255 A1.

[0057] List of reference numerals

[0058] 1 valve

[0059] 2 shells

[0060] 3 First Connector

[0061] 4 Second connector

[0062] 5 Third connector

[0063] 6 Interior Space

[0064] 7 channels

[0065] 8 First shut-off element

[0066] 9 Second shut-off element

[0067] 10 First Valve Seat

[0068] 11 Second valve seat

[0069] 12 intermediate spaces

[0070] 13 channels

[0071] 20 Adjustment Device

[0072] 21 First valve stem

[0073] 22 Second valve stem

[0074] 23 First Drive Module

[0075] 24 First Piston

[0076] 25 Second drive module

[0077] 26 Second Piston

[0078] 27 Third Piston

[0079] 28 Third Drive Module

[0080] 29 Fourth Piston

[0081] 30 nozzles

[0082] 31 control head

[0083] 32 Measurement Targets

[0084] 81 First Seal

[0085] 91 Second seal

[0086] 92 seats inside

[0087] 231 drive lever

[0088] 232 spring assembly

[0089] 233 First Working Face

[0090] 234 First stop

[0091] 251 Second Working Face

[0092] 252 Third Working Face

[0093] 253 Second Stop

[0094] 254 sliding bushing

[0095] 255 hub

[0096] 256 End of the second valve stem

[0097] 257 Fourth Stop

[0098] 281 Fourth Working Face

[0099] 282 boss

[0100] 283 travel limit structure

[0101] S-gap

Claims

1. A valve (1), the valve having: a housing (2) defining an internal space (6); a first connector (3); a second connector (4); a passage (7) connecting the first connector (3) and the second connector (4) in a flow-directing manner; a first closing element (8) and a second closing element (9) housed in the internal space (6) and surrounding an intermediate space (12) connected to a third connector (5); and an adjusting device (20) configured to, in a closed position, bring the first closing element (8) into sealing contact with a first valve seat (10) formed in the passage (7) and to bring the second closing element (9) into sealing contact with a second valve seat (11) formed in the passage, and in an open position, disengage the first closing element (8) and the second closing element (9) from the first valve seat (10) and the second valve seat (11), the first closing element (8) being sealedly housed in the second closing element (9), characterized in that, The second closing element (9) is cup-shaped, the intermediate space (12) is located inside the second closing element, and the first closing element (8) can be accommodated in the second closing element (9) such that the intermediate space (12) is sealed relative to the inner space (6), and the adjusting device (20) is configured such that when the first closing element (8) and the second closing element (9) are simultaneously lifted from the first valve seat (10) and the second valve seat (11) by the adjusting device (20), a gap (S) connecting the intermediate space (12) and the inner space (6) is formed between the first closing element (8) and the second closing element (9).

2. The valve according to claim 1, characterized in that, The adjusting device (20) includes a structural component (28) that cooperates with one of the first closing element (8) and the second closing element (9) and adjusts the closing element relative to the other closing element in the open position while forming the gap (S).

3. The valve according to claim 2, characterized in that, The structural component (28) includes a piston (29) that can be loaded with a pressure medium.

4. The valve according to claim 3, characterized in that, The piston (29) engages with the boss (282) on the valve stem (22) of the second closing element (9).

5. The valve according to any one of claims 2 to 4, characterized in that, The regulating device (20) includes at least two drive modules (23, 25, 28).

6. The valve according to claim 5, characterized in that, The structural components are housed in a separate drive module (28).

7. The valve according to claim 5, characterized in that, The regulating device (20) includes a drive module (23) that forms the open position of the valve (1).

8. The valve according to claim 7, characterized in that, The drive module (28) including the structural components is disposed between the housing (2) and the drive module (23) forming the open position.

9. The valve according to claim 5, characterized in that, At least one valve stem (21, 22) of the valve (1) is configured as a multi-part valve.

10. A method for cleaning a valve (1), the valve having an intermediate space (12) defined by a first closing element (8) and a second closing element (9) relative to an internal space (6), and the valve having a first valve seat (10) assigned to the first closing element (8) and a second valve seat (11) assigned to the second closing element (9), wherein in the closed position of the valve (1), the first closing element (8) is in sealing contact with the first valve seat (10) and the second closing element (9) is in sealing contact with the second valve seat (11), characterized in that, The second closing element (9) is cup-shaped, the intermediate space (12) is located inside the second closing element, and the first closing element (8) is accommodated in the second closing element (9) such that the intermediate space (12) is sealed relative to the inner space (6), allowing the first closing element (8) to move into a position lifted from the first valve seat (10) and the second closing element (9) to move into a position lifted from the second valve seat (11), and simultaneously forming a gap (S) between the first closing element (8) and the second closing element (9), the gap connecting the intermediate space (12) to the inner space (6).

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