DE10062791A1 - Gas supply device used for very pure corrosive gases comprises functional element having plastic base body, plastic membrane and non-metallic surfaces in gas contact regions of element - Google Patents

Abstract

A gas supply device comprises a functional element having a plastic base body (1), a plastic membrane (7) and non-metallic surfaces in the gas contact regions of the element. Preferred Features: The element is a membrane valve, multi-way valve, pressure regulator or safety valve. The element is connected to a plastic gas line. The base body has a part with a flat valve seat (6) in one region. The element contains one or more valve elements with a pneumatic upper part.

Description

The invention relates to a multi-way gas valve, a safety valve and the use extension of a plastic body with a multi-way gas valve.

Conventional gas fittings are described for example in "Gase-Handbuch", 3rd edition, Messer Griesheim GmbH 1989 , pp. 47-52.

Operation of a metallic gas valve with corrosive gases such as chlorine water substance, hydrogen bromide, chlorine, ammonia, tungsten hexafluoride or gas mixtures with A reactive component is very problematic in high-purity gas applications because contamination or contamination with metal ions from the valve material originate in the gas application area must be avoided in many cases got to. This is particularly true for the use of gas in the manufacture of semiconductors components.

The invention has for its object a gas supply system for Reinstga se, in particular for high-purity gases from corrosive gas.

The task was solved by a gas supply system with the in claim 1 described features.

The gas supply system contains functional elements that are in the gas-contact area have no metallic surfaces. Functional elements are, for example Shut-off valves, in particular diaphragm valves, multi-way valves, pressure regulators or Safety valves. The functional elements preferably have a plastic base body on. The functional elements of a lower part with a are advantageous Plastic body and a conventional upper part with metallic parts built up. The upper part is usually separated by a plastic membrane for valve-like functional elements. This not only reduces manufacturing cost, but leads to an improvement over pure plastic valves. The functional element with a plastic body is designed accordingly  can be used in the high pressure range (e.g. gas pressure greater than 50 bar, e.g. 300 bar). The Functional elements described below are of appropriate design suitable for the high pressure range (e.g. more than 50 bar), for which known art fabric valves are not suitable.

The functional element (e.g. shut-off valve, multi-way valve, pressure regulator) has one Base body (housing body; valve block) made of plastic, in the following art called basic material. Polyolefin, Fluorpo lymer, polyacetal, polyester or polyamide, e.g. B. polypropylene (PP), polyether ether ketone (PEEK), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE). As art Thermoplastic materials such as engineering plastics or chemical resistant plastics, especially high performance plastics, before trains used. The plastic base body preferably consists of one part, but can also consist of several, also of different materials Parts are put together.

The plastic base body of the valve-like functional elements (e.g. shut-off valve, Multi-way valve, pressure regulator) contains a gas inlet (incoming gas) nal), from which one, two, three or more gas channels emanate, each to egg Guide a valve element or safety valve element. Contains a multi-way valve z. B. two or three valve elements or one or two valve elements and a safe safety valve element. Each valve element or safety valve element has one Gas inlet and a gas outlet (outgoing gas duct or gas outlet duct) on. The basic body of each valve element or safety valve element is Be part of the plastic base body (e.g. a valve block).

The valve element has a lower part (base body) and an upper part with operating or the actuator. The valve element is of the diaphragm valve type. The Valve space of the valve element is generally in the lower area of the Plastic body and limited in the upper area by the valve membrane. The The valve chamber usually has a circular cross-section with a gas in the middle channel (gas inlet channel or gas outlet channel) opens and around the mouth opening  this gas channel the valve seat is arranged. The main body of the valve element or safety valve element, in contrast to conventional metalli cal valve body advantageously a valve seat with a special shape (esp their geometry).

The valve seat generally has an annular sealing surface or closing surface. The closing surface is preferably flat. Closing surface is advantageously in a plane that is perpendicular, almost vertical or in the range of 60 to 120 ° Valve adjustment axis runs. A vertical or almost vertical is preferred Alignment of the closing surface. In this case, the total closing area is flat Ring. With a slightly inclined closing surface (e.g. range from 60 to 120 ° to Valve adjustment axis), the annular closing surface lies on the jacket of one more or less blunt cone. The width of the closing surface in a ring part is generally in the range of 0.5 to 10 mm, preferably 2 to 6 mm, in particular 2 to 3 mm. On the total closing surface, the valve is closed Membrane pressed, whereby a gas channel is closed.

The valve membrane is usually disk-shaped. In mechanically undeformed The state of the membrane is preferably essentially on the closing side flat, especially in the area that serves to cover the valve seat. The Ven tilmembran consists partly or completely of a plastic, which as a rule is elastic. The plastic is preferably an elastomer such as rubber or synthetic table rubber. Synthetic rubbers are, for example, ACM, ANM, CM, CFM, CSM, EPDM, EPM, EVA, FPM, IM, CO, ECO, PO, ABR, BR, CR, IIR, IR, NBR, NCR, NR, PBR, SBR, SCR, SIR, T, FSi, PSi, PVSi, Si, VSi, AFMU, AU and EU. The The meanings of the abbreviations for synthetic rubbers are in "Hans Domining, "The plastics and their properties", VDI-Verlag, Düsseldorf, 1976 ", pp. 5 and 6, explains what is hereby incorporated by reference. Particularly preferred as a plastic are fluoroelastomers and chlorine-containing elastomers.

The membrane preferably has a support body, in particular an insert, on. The support body is made of plastic, ceramic or metal, preferably  Metal (e.g. steel, aluminum or brass). The support body advantageously has a Membrane support part and a connecting part. The support part of the support body is in usually plate or disc-shaped. The support part is advantageous partially or fully anchored in the membrane during the manufacture of the membrane, e.g. B. by Vulcanizing.

A firmer or stiffer membrane material is used for high pressure applications preferred, e.g. B. hard rubber. The plastic membrane is designed thicker for high pressure and in this case has a thickness in the range of z. B. 1 to 3 mm.

The membrane advantageously has a sealing edge which acts as a sealing element between Serves membrane and plastic body. The sealing edge is preferably on the Edge of the side of the membrane facing the valve space. The sealing edge is advantageously bead-shaped or rounded (e.g. semicircular). To accommodate the seal edge of the membrane faces the side of the art opposite the membrane base body advantageously a circumferential recess (z. B. groove or groove) in the Be range of the valve chamber edge.

The membrane support body is for example via the connecting part with the pressure body connected. The membrane support body can also be part of the pressure body, whereby the connecting part is unnecessary. To connect the membrane with the Pressure body, for example, the pressure body in the area of the bottom is modifi ed. For example, the pressure body is provided with a central cylindrical opening (e.g. Boh tion), which are used to hold the connecting part (e.g. a cylindrical pin) the membrane support body is used. Connecting part and the lower opening of the pressure body can be provided with a screw thread, so that the connection manure part can be screwed into the pressure body. The screw connection is in front partially fixed by an adhesive.

The valve spindle of the valve element is preferably in two or more parts. The The valve stem has, for example, a valve stem upper part and a separate one Pressure body on, as described in DE 39 35 171 A1 and to which reference  is taken. Valve stem and pressure body are preferably made of Me tall.

The upper part of a conventional diaphragm valve, for. B. the top of the diaphragm valve described in DE 39 35 171 A1 with a modified Pressure body, with the plastic membrane and the base body of a valve mentes combined. In this way, outside the gas-contact area metallic components, especially conventional components, are used, which in usually more favorable mechanical properties (e.g. higher stability) than Have plastic parts. Comes in the gas-wetted area of the functional element the gas only comes into contact with non-metallic parts or surfaces.

Instead of a manually operated valve upper part, the lower part of the valve elements is advantageously combined with a pneumatic head or pneumatic valve upper part. The pneumatic valve with plastic body and plastic membrane can be constructed in the same way as the pneumatic valves of the MV1 series from Messer Griesheim (see catalog "Gases with high purity 2000 ", Messer Griesheim GmbH, p. 170; or on the Internet: http: / /www.spezialgase. de).

The connections for gas inlet and gas outlet on the plastic body of the Functional elements are, for example, conventional hose or line connecting elements (e.g. compression fitting or compression fitting), the are also available in plastic. The connection elements can be directly in the Plastic base body are inserted so that transition pieces for the Connection of the functional element are not required.

In principle, a valve element with the opposite direction of the gas flow can be inserted be set. Multi-way valves with multiple gas inlets and build a gas outlet, e.g. B. a two-way valve with two gas inlets and a gas outlet or a three-way valve with three gas inlets and one gas output.  

A pressure regulator with a plastic body contains a lower part that is similar to one Valve element is constructed. The pressure regulator also contains a closing spring and a control cone, which is arranged in a cavity in the plastic base body are. The cavity is connected to the incoming gas channel and the valve space the. The cavity is usually on one side by a plastic closure partially closed. The plastic closure part preferably consists of the same Chen plastic like the basic body. The closing spring and the control cone are the best hen preferably made of metal, particularly preferably stainless steel, and are plastic coated. In particular, the closing spring is preferably made of plastic layered metal because of the advantageous mechanical / resilient properties metal. The plastic coating is preferably made of fluorine plastics such as PTFE, PFA or tetrafluoroethylene copolymer (e.g. PFEB). The control cone can also be made of plastic, e.g. B. PEEK. or ceramic. All surfaces in contact with gas are therefore made of plastic or a non-metallic material material. The actuating spring presses on the membrane support body. The top of the pressure regulator includes spring, cap screw and adjusting handwheel. Advantageous becomes the upper part of a common pressure regulator with the plastic membrane and the plastic body combined.

The pressure regulator works analogously to conventional pressure regulators, which are described, for example, in "Gases Manual", 3rd edition, Messer Griesheim GmbH 1989 , pp. 47-49, to which reference is hereby made.

The construction of a functional element, in particular a valve system, with a Plastic base body allows a modular structure. A plastic body with one, two, three or more lower parts (heads), especially valve lower share, can easily with various functions (by combination with various upper parts) such as valve elements with manual operation, pneumatic Valve elements, a safety valve element, a pressure regulator element or other elements to save space and minimize dead space.  

With the described diaphragm valves, multi-way valves, pressure regulators and Si Safety valves, all of which have a plastic base body, plastic gas lead different gas connections Build care systems that are exposed to gas through non-metallic surfaces Are marked.

The invention is explained with reference to the drawing.

Fig. 1 shows a schematic of a diaphragm valve in cross section.

Fig. 2 shows a schematic of a two-way valve in cross section.

Fig. 3 shows a schematic of a three-way valve in cross section.

Fig. 4 shows a side section through a valve element.

Fig. 5 shows a schematic of a safety valve element in cross section.

Fig. 6 shows a diagram of a three-way valve with valve elements and safety valve element.

Fig. 7 shows a schematic of a three-way valve with valve elements and safety valve element in plan view.

Fig. 8 shows a schematic of a pressure regulator in cross section.

Figure 9 shows a schematic of a preferred gas supply system.

The example of a diaphragm valve according to the invention shown in FIG. 1 has a base body 1 made of plastic, which contains the incoming gas channel 2 and the outgoing gas channel 3 (outlet channel). The plastic body is e.g. B. from PP, PEEK, PVDF or PTFE. The choice of plastic depends on the desired chemical resistance and the intended gas pressure. In the upper loading area of the base body 1 , the valve seat 6 is arranged, which has an annular or disk-shaped plateau, preferably with a flat closing surface in a plane perpendicular to the valve axis AA. Between the valve seat 6 and the valve membrane 7 is of the so-called valve chamber. The plastic membrane 7 is preferably disc-shaped and contains a sealing edge which is received by the recess 5 (sealing groove or groove). The membrane 7 is clamped on its edge between the plastic body 1 in the region of the recess 5 and cap screw 12 . The membrane 7 is advantageously pre-pressed over a defined tolerance (height) of the web in the valve body 1 and the height (thickness) of the membrane 7 without the material of the membrane being excessively stressed or caused to flow. In this way, a permanently elastic sealing of the membrane is achieved with constant restoring force. The membrane is preferably made of a synthetic rubber such as EPDM or a fluoroelastomer. The membrane 7 surrounds the lower part (support part) of the membrane support body 8 . The preferably scheibenför shaped support member is integrated in the manufacture of the membrane in the membrane material, for. B. vulcanized. The upper part of the membrane support body 8 serves as a connecting part for fastening the membrane to the pressure body 10 . The pressure body 10 has, for example, a threaded opening on the underside into which the connecting part is screwed. The screw connection between the membrane support body 8 and the pressure body 10 is advantageously fixed with an adhesive (eg superglue). The pressure body 10 is non-positively but rotatably connected to the valve spindle 11 . Pressure body 10 , valve upper spindle 11 and head screw 12 form the valve upper part and are preferably made of metal. Parts of conventional diaphragm valves can be used as the upper valve part. The valve upper part is constructed, for example, as described in DE 39 35 171 A1 and to which reference is hereby made. The cap screw 12 is screwed onto the thread 4 of the base body 1 . The connections 13 are arranged in the valve body 1 . The connections 13 are, for example, customary compression fittings. The gasbe stirred space (gas channels 2 and 3 and the valve space) contains no metallic surfaces in the membrane valve according to the invention. The gas only comes into contact with plastic surfaces. This prevents contamination of the gas with metal ions.

The valve parts above the horizontal dashed line in Fig. 1 represent a Ven tilelement (z. B. 13, 14, 15 in Fig. 2 and 3), which is usually included in a valve system or multi-way valve according to the invention.

In principle, the valve or valve element can be used with the reverse direction of the gas flow, which is shown in the example of FIG. 1.

The two-way valve of Fig. 2 has a plastic base body 1 with two valve elements 13 and 14 . The incoming gas channel 2 comes from a gas inlet on the plastic base body 1 and is perpendicular to the paper plane, where it branches into two gas channels, each of which a gas channel leads to a valve element. The outgoing gas channel 3 of the valve elements 13 , 14 leads to a gas channel that runs perpendicularly below the paper plane and ends at a gas outlet on the plastic base body 1 . The outgoing gas channel 3 is shown in FIG. 2 to the side of the incoming gas channel 2 for easier illustration. The outgoing gas channel 3 is preferably located behind the gas channel 2 , as can be seen in FIG. 4. Axis AA represents the valve adjustment axis of a valve element.

The three-way valve of FIG. 3 is constructed analogously to the two-way valve of FIG. 2. The three-way valve has the valve elements 13 , 14 , 15 . The outgoing gas channel 3 of each valve element is behind the incoming gas channel and then goes vertically below the paper level. This is shown by the dashed circles.

FIG. 4 shows a section perpendicular to the paper plane through the axis AA in FIG. 2 (gas channel 3 shown differently) or FIG. 3. The gas connections 16 and 17 are embedded in the plastic body 1 . The gas connections 16 and 17 are, for example, compression fittings made of plastic.

The safety valve element 20 (overflow valve or relief valve) in FIG. 5 is a safety device which is arranged on the plastic base body 1 of a multi-way valve instead of a valve element (for example 13, 14 or 15). In the overflow valve shown, the membrane opens when a defined blow-off pressure that can be set by the steep spring 18 is reached. With the adjusting handwheel 19 , the pressure force of the adjusting spring 18 is adjusted. The upper part with the cap screw 12 is mounted on the lower part arranged in the plastic base body 1 . Conventional parts (generally essentially made of metal) are advantageously used as the upper part.

Fig. 6 shows schematically the structure of a multi-way valve (1/3) with plastic base body 1, two valve elements 13 and 14 and a relief valve 20th The multi-way valve shown is an example of a combination of valve elements and other functional elements such as a safety valve element (modular design concept). The incoming gas channel 2 splits into the gas channels leading to the valve elements 13 and 14 and the relief valve 20 . The outgoing gas channels 3 lead from these functional elements to the respective gas outlets. This multi-way valve is shown in plan view in FIG. 7. The connection 16 (for gas line or gas hose) is at the gas inlet and the connections 17 , 17 'and 17 "are arranged at the gas outlets. The multi-way valve with the plastic block 1 and the integrated relief valve 20 permits a very space-saving and dead space-minimized construction is particularly cost-effective to produce thanks to the usability of upper parts of conventional valves and has no metallic surfaces in the gas-contacting room.

The example shown in Fig. 8 of a pressure regulator according to the invention has a base body 1 made of plastic, which contains the incoming gas channel 2 and the outgoing gas channel 3 (outlet channel). Base body 1 contains a central cavity 24 (preferably in the longitudinal axis AA), which is connected to the gas channel 2 and the valve chamber 28 and is closed with a closure part 23 (eg screw part). The control cone 26 and the closing spring 21 are arranged in the cavity 24 . The control cone 26 has the pin-like extensions 25 and 27 which guide the control cone. The plastic body 1 and the closure part 23 are, for. B. from PP, PEEK, PVDF or PTFE. The choice of plastic depends on the desired chemical resistance and the intended gas pressure. The plastic membrane 7 is preferably disc-shaped and contains a sealing edge which is received by the recess 5 (sealing groove or groove). The membrane 7 is clamped on the edge between the plastic body 1 and the intermediate ring 22 by means of the head screw 12 . The diaphragm 7 via a defined tolerance (height) of the ridge in the valve body 1 and the height (thickness) of the diaphragm 7 is prepressed defi ned advantageous, without causing the material of the membrane sprucht excessively bean or is caused to flow. In this way, a permanently elastic sealing of the membrane is achieved with constant restoring force.

The membrane is preferably made of a synthetic rubber such as EPDM or a fluoroelastomer. The membrane serves as a control element, for which membrane material properties are preferred, which compromise between mechani shear strength and elasticity and at the same time corrosion-resistant is given. The membrane has a thickness in the range of 1 to, for example 3 mm.

The membrane 7 surrounds the lower part of the membrane support body 8 . The membrane support body 8 is integrated with the lower part in the membrane ranmaterial in the manufacture of the membrane, for. B. vulcanized. The upper part of the membrane support body 8 serves as a support for the actuating spring 18 . The membrane support body 8 is made of metal (e.g. stainless steel) or preferably plastic (e.g. PEEK, PVDF, PP). The force emanating from the actuating spring 18 is set with the hand setting wheel 19 . The upper part of the pressure regulator with cap screw 12 , adjusting spring 18 and hand setting wheel 19 advantageously corresponds to conventional pressure regulators with metallic parts outside the gas-contacted area.

To assemble the control unit with control cone 26 and closing spring 21 , the closure part 23 is opened and the control cone 26 and the closing spring 21 are inserted into the cavity 24 . The gas space of the cavity 24 is connected to the valve space 28 via a gas channel. The extension 27 (“plunger”) of the control cone 26 is guided through this gas channel. The extension 27 is pressed into a central opening on the underside of the membrane support body 8 . The pin-shaped extension 25 of the control cone 26 is guided in a cylindrical opening in the closure part 23 . The length of this cylindrical opening is such that the control cone 26 can perform an up and down movement to regulate the gas pressure.

The closing spring as well as the control cone 26 with the pin-like extensions 25 and 27 are preferably made of metal, in particular stainless steel, and are plastic-coated (e.g. PTFE or thermoplastic fluoropolymer coating).

The gas-contacted space (gas channels 2 and 3 and the valve space) contains no metallic surfaces in the pressure regulator according to the invention. The gas only comes into contact with plastic surfaces. This prevents contamination of the gas with metal ions.

The gas supply system (gas panel) in Fig. 9 is a preferred embodiment and is composed of parts with a non-metallic surface in the gas path. The gas panel is therefore particularly suitable for high-purity gas applications with corrosive gases such as hydrogen chloride, chlorine or ammonia or gas mixtures with one or more reactive components, e.g. B. in the manufacture of semiconductor devices for electronic applications. All parts of the gas supply system have non-metallic surfaces in the gas-contact area. The pressurized gas source 29 (z. B. compressed gas cylinder with the process gas) is advantageously equipped with egg nem horizontal gas valve that on a plastic connecting part 31 (e.g., as a "compression fitting") is connected with a plastic gas line 32. The gas valve 30 is advantageously a diaphragm valve with a plastic base body, as described by the construction type in FIG. 1. The horizontal gas valve is advantageously constructed analogously to the cylinder valve, as described in DE 296 23 008 U1 (internal designation MG 1976 ). The plastic gas line 32 advantageously consists of PEEK or another chemical-resistant and pressure-stable plastic material. The plastic gas line has z. B. an outer diameter of 1/8 "(inches) and depending on the application gas pressure an inner diameter of, for example, 0.75" at up to 350 bar, 1.60 "at up to 280 bar and 2.0" up to 210 bar. The plastic gas line 32 leads from the gas valve 30 to a three-way valve 33 with a plastic base body, which is described in Fig. 3. The three-way valve 33 is connected to the wide plastic gas lines 39 (outgoing process gas), 34 (incoming purge gas) and 35 (outgoing purge gas). The plastic gas line with the process gas leads to a T-piece or T-block 39 made of plastic parts, which is connected to a pressure measuring device 41 (manometer) and to a pressure regulator 43 via a plastic gas line. A pressure regulator with a plastic base body, as described in FIG. 8, is preferably used as the pressure regulator 43 . A plastic gas line leads from the pressure regulator 43 to a further T-piece or T-block 40 made of plastic parts, which is connected to a pressure gauge 42 (manometer) and via a plastic gas line with a three-way valve 45 with a plastic base body, two valve elements and a safety valve element (blow-off valve, see Fig. 5) is connected (see Fig. 7). The three-way valve 45 is with the plastic gas lines 38 (outgoing process gas), 36 (outgoing purge gas) and 46 (gas outlet of the safety valve element in the three-way valve 45 ). The display unit 44 shows the measured values of the pressure measuring devices 41 and 42 .

The valves 30 , 33 and 45 are operated manually. Individual or all of the valves mentioned can be equipped with pneumatic valve elements, with which the gas supply system can be automated in a simple manner.

reference numeral

1

Plastic body

2

incoming gas channel

3

outgoing gas channel

4

Thread on the plastic body

5

all-round recess to take on the sealing edge of the membrane

6

valve seat

7

Plastic membrane

8th

Membrane support body

9

sealing element

10

pressure vessels

11

Valve stem shell

12

up end caps

13

.

14

.

15

valve element

16

Gas connection (entrance)

17

.

17

'

17

"Gas connection (exit)

18

spring

19

Adjusting handwheel

20

Safety valve element (via flow valve or blow-off valve)

21

closing spring

22

intermediate ring

23

closing part

24

cavity

25

pin-shaped extension of the control cone

26

usually conical

27

pin-shaped extension of the control cone

28

valve chamber

29

Pressurized gas source (e.g. pressurized gas container)

30

horizontal shut-off valve with non-metallic surface in the gas-contact area

31

Connection part (compression fitting)

32

Plastic gas line

33

Three-way valve

34

Purge

35

.

36

Purge Gas

37

.

38

process gas

39

.

40

Tee

41

.

42

pressure gauge

43

pressure regulator

44

display

45

Three-way valve with blow-off valve

46

Abblasventilausgang

Claims (12)

1. Gas supply system with at least one functional element, which has a plastic base body ( 1 ), a plastic membrane ( 7 ) and non-metallic surfaces in the gas-wetted area of the functional element. 2. Gas supply system according to claim 1, characterized in that the Functional element a diaphragm valve, a multi-way valve, a pressure regulator or a Safety valve is or at least one valve element or at least one safe has safety valve element. 3. Gas supply system according to claim 1 or 2, characterized in that the functional elements of the gas supply system are connected to a plastic gas line ( 32 ). 4. Gas supply system according to one of claims 1 to 3, characterized in that the plastic base body ( 1 ) of the functional element has at least one part with a substantially flat valve seat ( 6 ). 5. Gas supply system according to one of claims 1 to 4, characterized in that the plastic base body ( 1 ) of the functional element in at least one area has a circumferential recess ( 5 ) for receiving a membrane sealing element. 6. Gas supply system according to one of claims 1 to 5, characterized in that a functional element contains a plastic membrane ( 7 ) which has a membrane support body ( 8 ). 7. Gas supply system according to one of claims 1 to 6, characterized in that a functional element contains one or more valve elements ( 13 , 14 , 15 ) and, if appropriate, a safety valve element ( 20 ) which has a customary or commercially available valve upper part with metallic parts exhibit. 8. Gas supply system according to one of claims 1 to 7, characterized in that a functional element contains one or more valve elements ( 13 , 14 , 15 ) which have a pneumatic upper part. 9. Gas supply system according to one of claims 1 to 8, characterized in net that the gas supply system is suitable for high pressure. 10. Use of a valve-like functional element with a plastic base body ( 1 ) and an upper part with metallic parts in a gas supply system. 11. Use according to claim 10, characterized in that the plastic base body ( 1 ) is used in combination with a plastic membrane ( 7 ). 12. Use according to claim 10 or 11, characterized in that the plastic base body ( 1 ) is used in combination with a customary valve upper part.