FLEXIBLE PRESSURE DISTRIBUTION ELEMENT

Description

[0001] The invention relates to a valve with a membrane arrangement comprising a membrane, a pressure piece and a hood, wherein a pressure distribution element is arranged between the membrane and the pressure piece.

[0002] An important quality characteristic of a diaphragm is its mobility, i.e., its ability to perform a stroke perpendicular to the clamping surface (diaphragm surface), which can be mechanically driven. Furthermore, the durability of the diaphragm is important, especially when handling aggressive media.

[0003] The mobility and durability of a membrane depend essentially on the material it is made of. Elastomers are primarily used as the base material for membranes, which can be reinforced with fabric inserts to achieve greater strength. Membranes made of ethylene propylene diene rubber (EPDM) have proven to be effective elastomers. Ethylene propylene diene rubber (EPDM) is a terpolymer elastomer (rubber) and thus a synthetic rubber. The material is characterized by high elasticity and good chemical resistance.

[0004] The diaphragm is firmly clamped between a lower housing section and an upper housing section. The upper housing section is also called the hood and forms the superstructure containing the diaphragm drive. The hood integrates the drive spindle, the spindle seal, and the drive itself. Depending on the drive, the hood has a considerable mass, which acts on the lower housing section and must be transferred into it.

[0005] The piston rod in a diaphragm valve is a cylindrical machine element connected to the diaphragm by a diaphragm screw, which deforms the diaphragm into position. The piston rod is moved in its specified direction by a drive. The drive can be manual, electric, pneumatic, or hydraulic.

[0006] The diaphragm screw is a pin-like element that is positively integrated into a layer of the diaphragm. The diaphragm screw is connected to the actuator spindle via the piston rod. This allows the diaphragm to be deformed.

[0007] To stabilize the membrane, support arrangements in the form of spirals resting on the membrane are known on the side facing away from the fluid and thus on the side facing the hood, which can partially compensate for a permanent damaging deformation in the open position.

[0008] DE 28 39 804 discloses a diaphragm valve with a diaphragm clamped at its edge between the valve housing and a cap attached thereto, which is brought into sealing engagement with a seat provided in the valve housing via a pressure piece. Arranged in the cap are radial ribs projecting into recesses in the pressure piece, the end faces of which correspond in contour to the fully opened diaphragm. A diaphragm support is arranged between these end faces and the pressure piece on one side and the diaphragm on the other side, largely adapting to the contour of the end faces and the pressure piece. The diaphragm support is formed by a spiral with a small gap between the turns.

[0009] WO 2020 / 203553 A1 describes a membrane with through holes provided therein, the diameter of which is larger than the diameter through which a bolt can comfortably pass. Metal bolt insertion tubes are fitted into the through holes and can be inserted into the bolts. The height of the bolt insertion tubes is equal to or less than the height of the through holes.

[0010] US 1 647 823 discloses a valve comprising a valve chamber, a flexible diaphragm closing and forming a wall of the chamber, a valve stem attached to the diaphragm, a stationary annular member on the outside of the diaphragm and having outwardly inclined stationary arms extending towards the valve stem, upwardly inclined arms attached to the stem and extending between the stationary arms, and concentric wires on the outside of the diaphragm supporting the diaphragm and held by the stationary arms.

[0011] DE 10 2018 213 002 A1 shows a device for diagnosing a diaphragm of a diaphragm valve or a diaphragm pump, comprising a first component consisting of a diaphragm provided in a housing, wherein a part of the diaphragm protrudes from the housing, and a second component consisting of a data acquisition device, wherein at least one sensor for detecting operating parameters is provided in the diaphragm, wherein a transmitter is provided between the diaphragm and the data acquisition device.

[0012] DE 1 500 140 relates to a diaphragm valve with a diaphragm clamped between the lower part of the valve housing and the upper part of the housing, connected in its center to the valve spindle via a pressure piece, with fixed ribs provided on the upper part of the housing and projecting radially into the interior of the diaphragm and with arms provided on the pressure piece and spaced from the fixed ribs, wherein the edges of the ribs facing the diaphragm represent concavely shaped pressure surfaces rising towards the spindle axis, while the corresponding edges form arms on the pressure piece which are convexly shaped and descend towards the spindle axis.

[0013] EP 3 366 961 B1 describes a valve with a diaphragm having an edge arranged in a chamber formed by a housing part and a cover. A pressure distribution element in the form of a support coil is arranged between the pressure piece and the diaphragm to support the diaphragm in the open position.

[0014] However, due to their rigidity, such pressure distribution elements or support coils have so far only been used in sufficiently large diaphragm valves. The diaphragms of smaller valve series receive only limited support from a pressure piece, if present, and tend to wear more quickly or experience more frequent damage due to elastomer relaxation under the given temperatures and pressures compared to diaphragms of larger valve series that are supported by a support coil.

[0015] The object of the invention is to provide a diaphragm valve that protects the diaphragm as effectively as possible from damage. The diaphragm is to be protected from damage caused by deformation through holistic support. Furthermore, the diaphragm valve should meet the requirements of continuous operation while maintaining extremely durable properties. The diaphragm valve should be as inexpensive and simple to manufacture as possible.

[0016] This object is achieved according to the invention by a valve with a membrane arrangement according to the features of claim 1. Preferred variants can be found in the subclaims, the description and the drawings.

[0017] According to the invention, the pressure distribution element is designed as a flexible ring arrangement, wherein the ring arrangement comprises an inner ring segment and an outer ring segment and the ring arrangement is designed as an endless ring and as a closed construct, wherein the outer ring segment becomes increasingly wider in the circumferential direction until a spiral segment branches off from the outer ring segment at the widest point of the outer ring segment, wherein the spiral segment runs in a uniform width and opens into the inner ring segment at the widest point of the inner ring segment.

[0018] A ring arrangement is preferably circular and has an annular opening in the center, which serves to establish an operative connection with the pressure piece. The ring arrangement comprises at least one ring segment, which preferably has a circular cross-section. Depending on the size and shape of the diaphragm valve, the cross-section of the ring segment(s) can be adapted to the support function.

[0019] In a particularly advantageous variant, the ring arrangement comprises a ring segment and at least one spiral segment. The inner ring segment is connected to a spiral segment. Preferably, the inner ring segment becomes wider in the circumferential direction, and at its widest point, the spiral segment originates from the inner ring segment, which then continues spirally.

[0020] The ring assembly also includes an outer ring segment. The inner ring segment is connected to the outer ring segment via a spiral segment. The spiral segment merges into the outer ring segment, creating a seamless transition between the individual segments. The outer ring segment is ideally shaped to fit against the hood and support the spiral until the membrane is chambered or clamped.

[0021] In addition, the inner and outer ring segments, as well as the spiral segment, can be made of the same material. To specifically adjust the flexibility of the pressure distribution element, the segments of the ring arrangement can also be made of different materials. Metallic and / or rubber-like materials are particularly suitable for this purpose.

[0022] In an alternative variant of the invention, the spiral segment can be designed as a single-start or multi-start wire spiral in which one or two wires are wound over each other to form a spiral.

[0023] To adjust the stiffness and elasticity of the pressure distribution element, the segments of the ring arrangement can also be designed as hollow segments. This is particularly easy to achieve through additive manufacturing of the ring arrangement.

[0024] In a further advantageous variant, the segments have different heights and widths to adjust the stiffness and elasticity of the pressure distribution element. A particularly advantageous feature is the uniform design of the inner and outer ring segments, with one or more spiral segments with a significantly smaller cross-section being arranged between the outer and inner ring segments.

[0025] Advantageously, the ring arrangement, preferably the inner ring segment and the pressure piece, has an operative connection. The operative connection can be designed as a force-locking and / or form-locking connection. As a result, the ring arrangement experiences the movement required to deform the diaphragm in the same way as the diaphragm itself, thereby specifically supporting the diaphragm for protection.

[0026] Ideally, the support of the diaphragm by the ring arrangement is ensured by the hood having a shoulder that is operatively connected to the ring arrangement. Preferably, the shoulder is designed as a stop surface for the ring arrangement, which ensures support, especially in the open position of the diaphragm.

[0027] In a favorable variant of the invention, the ring arrangement is at least partially formed from an elastic material. For this purpose, the inner ring segment and / or the outer ring segment and / or the spiral segment can be formed from a rubber-like, elastomeric material. In a further variant, the entire ring arrangement can also be formed from an elastomeric material.

[0028] Depending on the material design and combination, the inner and / or outer ring segment is connected to the spiral segment in a force-fitting, material-fitting or form-fitting manner.

[0029] In a particularly advantageous variant, the ring arrangement is produced generatively. Generative or additive manufacturing processes are processes in which material is applied layer by layer to create a three-dimensional structure of the ring arrangement. According to the invention, the ring arrangement is designed as a generatively manufactured structure. Selective laser melting and cladding, also known as build-up welding, are used in particular to form the ring arrangement. In an alternative variant of the invention, extrusion in combination with the application of meltable plastic is also a suitable process.

[0030] The ring arrangement is preferably formed as a single piece, with recesses arranged within the ring arrangement to increase elasticity. The recesses can be formed, in particular, by a laser process in a metallic or elastomeric material, for example as cuts. The recesses can have the identical, spiral course of the spiral segment. The number of recesses allows the flexibility of the ring arrangement to be specifically adapted to the needs of the respective diaphragm valve in order to ensure diaphragm support and increase service life. At the same time, the single-piece design of the ring arrangement is particularly easy to install, both during initial installation and during interval-based diaphragm replacement.

[0031] In a particularly advantageous variant of the invention, the recesses are designed in the form of cuts.

[0032] The particularly flexible and compliant design of the ring arrangement makes the pressure distribution element particularly suitable for smaller valve series. The thickness of the ring arrangement can be specifically adjusted to the desired stiffness. Furthermore, the spiral segment can be designed with multiple or partially multiple threads to specifically adjust the flexibility of the pressure distribution element.

[0033] Compared to fabric-reinforced diaphragms, supporting the diaphragm with a ring arrangement is more suitable for use at higher pressures and higher temperatures, as the support effectively counteracts the relaxation of the elastomeric diaphragm material and ensures damage-free operation even over longer periods. This advantage also applies to diaphragm valves with partial diaphragm support by the negative side of the pressure piece in the bonnet.

[0034] The design of the pressure distribution element as a flexible ring arrangement is equally suitable for chambered and clamped membranes.

[0035] Further features and advantages of the invention will become apparent from the description of embodiments with reference to drawings and from the drawings themselves.

[0036] It shows: Fig. 1 an exploded view of a diaphragm valve, Fig. 2 a sectional view of a pressure distribution element, Fig. 3 a perspective sectional view of the pressure distribution element, Fig. 4 a perspective view of the pressure distribution element, Fig. 5 a sectional view of a simple pressure distribution element.

[0037] Fig. 1 shows an exploded view of a valve with a diaphragm arrangement 16. The valve comprises a housing part 1, a diaphragm 2, a pressure distribution element 3, a pressure piece 4 and a hood 5.

[0038] In this embodiment, the pressure distribution element 3 is shown in use with a chambered membrane 2. The pressure distribution element 3 according to the invention can be used in all clamped valve membranes 2.

[0039] The membrane 2 is formed in one piece from a polymer material and has a flat area 6, which is adjoined by an edge 7. The flat area 6 is curved downwards. The edge 7 extends vertically upwards as viewed in the drawing. The flat area 6 is plate-shaped. The edge 7 is bead-like.

[0040] The edge 7 of the diaphragm 2 projects upwards in a vertical direction and has a circumferential end face 23 on its upper side. The end face 23 is curved. Thus, the end face 23 of the edge 7 of the diaphragm 2 does not lie in a horizontal plane, but is curved in a vertical direction. The curvature of the end face 23 has its lowest point in the area of ​​the diaphragm web or diaphragm weir and then increases on both sides, so that in the inlet area the end face 23 of the edge 7 of the diaphragm 2 has the highest elevation, then steadily decreases down to the valve seat or the web or weir and then increases again towards the outlet and then increases again to the same height. The curvature of the end face 23 of the edge 7 of the diaphragm 2 thus runs parallel to the direction of flow.

[0041] In the exemplary embodiment, the diaphragm 2 is designed such that the lowest tension acts in the material of the diaphragm 2 in the closed position. When the valve is opened, the diaphragm 2 is deformed and the tension in the diaphragm material increases. An element is positively embedded in the diaphragm 2 and is connected to a drive (not shown) for deforming the diaphragm 2. In the exemplary embodiment, the element 8 is a diaphragm screw. The element 8 is connected to a pressure piece 4. The pressure piece 4 can be moved vertically within the hood by means of a drive (not shown). The pressure distribution element 3 distributes the pressure exerted by the pressure piece 4 onto the flat area 6 of the diaphragm 2. The pressure distribution element 3 is designed as a ring arrangement 30 in the exemplary embodiment.

[0042] The pressure piece 4 has an inner opening 9 for connection to a drive. Four arms 10 extend outward, so that the pressure piece 4 has a cross-shaped design in plan view. The hood 5 has a flat area 11 that is curved downwards. A circumferential elevation 12 extends downwards. In the center, the hood 5 has a hollow cylindrical neck 13 with a circular opening 14 for drive elements (not shown), such as a spindle.

[0043] The hood 5 has a cavity 15 in which the pressure piece 4 is arranged so as to be displaceable in the vertical direction. In the open position, the pressure distribution element 3 is pressed against the membrane 2 by a limiting shoulder 15 of the hood 5.

[0044] In Fig. 2 A sectional view of a pressure distribution element 3 in the form of a ring arrangement 30 is shown. The inner ring segment 31 is connected to the outer ring segment 32 via an upper and a lower spiral segment 33 and forms a highly elastic ring arrangement 30 for flexible support of the diaphragm 2, particularly for small diaphragm valves.

[0045] For this purpose, the spiral segment 33 is designed as a wound spiral, significantly thinner than the inner ring segment 31 and the outer ring segment 32, and is constructed in two parts. The unfilled cavity 35 supports the elastic and resilient design of the ring arrangement 30. Furthermore, the spiral segment 33 is manufactured generatively as a hollow spiral. The inner ring segment 31 is positively connected to the pressure piece 4 (not shown). The outer ring segment 33 is positioned within the diaphragm valve by the shoulder 15 (not shown) of the cap 5.

[0046] Fig. 3 shows a perspective sectional view of the pressure distribution element 3, which is designed as a ring arrangement 30. The ring arrangement 30 is designed as an endless ring and as a closed structure. The outer ring segment 32 becomes increasingly wider in the circumferential direction until a spiral segment 33 branches off from the outer ring segment 32 at the widest point 39 of the outer ring segment 32. The spiral segment 33 runs with a uniform width and opens into the inner ring segment 31 at the widest point 38 of the inner ring segment 31.

[0047] The ring arrangement 30 is made of a metallic or plastic-like material. The recesses 34 in the spiral segment 33 are formed using a laser to ensure the elastic and resilient design of the ring arrangement 30. The inner ring segment 31 connects in a form-fitting manner to the partially illustrated pressure piece 5 and thus forms a unit for deforming and supporting the membrane 2.

[0048] Fig. 4 shows a perspective view of the pressure distribution element 3 in the exemplary embodiment of a ring arrangement 30. The ring arrangement 30 is manufactured as a closed construct generatively from a metallic material. The spiral segment 33 originates from the inner ring segment 31 through the arrangement of recesses 34 and opens through the ends of the recesses 34 in the outer ring segment 32. The spiral and simultaneously hollow design of the ring arrangement 30 results in a very flexible and resilient pressure distribution element 3, which can also be used in smaller diaphragm valves to support the diaphragm 2 and is designed to be sufficiently movable. The ring arrangement 30 is non-positively connected to the pressure piece 5 (not shown) by the inner ring segment 31.

[0049] In Fig. 51 shows a sectional view of a simple pressure distribution element 3 in the form of a ring arrangement 30. The ring arrangement 30 is essentially reduced to the inner ring segment 31. For resting and supporting the membrane 2, the inner ring segment 31 has a lower curvature 37, and for bearing against the shoulder 15 of the hood 5, the inner ring segment 31 has an upper curvature 36. The ring arrangement 30 shown is made of a metallic material. In an alternative variant, the ring arrangement 30 can also be made of a plastic. The inner ring segment 31 can be positively and / or non-positively connected to the pressure piece 4. Alternatively, the ring arrangement 30 could also be inserted loosely.

Claims

1. Valve having a diaphragm arrangement (16), which diaphragm arrangement comprises a diaphragm (2) and a pressure piece (4) and a cover (5), wherein a pressure-distribution element (3) is arranged between the diaphragm (2) and the pressure piece (4), wherein the pressure-distribution element (3) is in the form of a flexible ring arrangement (30), wherein the ring arrangement (30) comprises an inner ring segment (31) and an outer ring segment (32), characterized in that the ring arrangement (30) is in the form of an endless ring with a closed construction, wherein the outer ring element (32) increases in width in a circumferential direction until a spiral segment (33) branches off from the outer ring segment (32) at the widest point (39) of the outer ring segment (32), wherein the spiral segment (33) runs with a uniform width and opens out into the inner ring segment (31) at the widest point (38) of the inner ring segment (31).

2. Diaphragm valve according to Claim 1, characterized in that the ring arrangement (30) and the pressure piece (4) have an operative connection.

3. Diaphragm valve according to either of Claims 1 and 2, characterized in that the cover (5) has a shoulder (15) which is in operative connection with the ring arrangement (30).

4. Diaphragm valve according to one of Claims 1 to 3, characterized in that the ring arrangement (30) is formed at least partially from an elastic material.

5. Diaphragm valve according to one of Claims 1 to 4, characterized in that the inner ring segment (31) and / or the outer ring segment (32) are / is connected in a force-fitting and / or materially bonded and / or form-fitting manner to the spiral segment (33).

6. Diaphragm valve according to one of Claims 1 to 5, characterized in that the ring arrangement (30) is produced generatively.

7. Diaphragm valve according to one of Claims 1 to 6, characterized in that the ring arrangement (30) is of single-part design, wherein cutouts (34) are arranged within the ring arrangement (30) for the purpose of increasing the elasticity.