DE3724104A1 - Pneumatically operated double-diaphragm pump - Google Patents

Abstract

A pneumatically operated double-diaphragm pump has a central control block (1), with on each side an air chamber (2) closed on the outside by a composite diaphragm (20), a casing cheek (3, 4) located on both sides of the control block (1), a pump chamber (5) and a pump channel (7), in which a suction valve (11) is located at one end and a head valve (9) at the other, and a suction branch (14) and a discharge branch (17) between the casing cheeks (3, 4). It is arranged so that on both sides of the control block (1) a blocking chamber (19) closed to the outside is provided between two identical composite diaphragms (20, 21), and the blocking chamber (19) is bounded by a blocking chamber ring (22) in the area of the outside circumference of the composite diaphragms (20, 21). <IMAGE>

Description

The invention relates to a compressed air operated double diaphragm pump with a central control block attached to the sides one each from the outside of a composite membrane has closed air chamber, and one each housing cheek arranged on both sides of the control block with a pump chamber and a pump channel, in which on a suction valve at one end and a pressure at the other end valve is arranged, and with a suction port and a pressure port between the housing cheeks.

From German utility model 84 32 047 a compressed air operated double diaphragm pump with one central control block, one housing cheek to each Sides of the control block and a suction housing and one Pressure housing known. There is one in both ends Control block reciprocating piston rod  A composite membrane is provided, which in the central Control block arranged air chamber from the one in the opposite Pump chamber provided overlying housing cheek separates.

With such a compressed air operated double diaphragm pump A membrane breakage cannot be ruled out. It cannot be predicted or be in advance count.

In the event of a membrane rupture of such a double meme branch pump with only one diaphragm per pump chamber air gets into the product and product into the tax block. That has product contamination by air or Oxidation of the product, so that the product, if it is a high quality and high purity product acts, is unusable. In such a case the Great damage technically and economically.

If product gets into the control block, it means a loss of product, which is a big technical and represents economic damage when it is is a high quality product. Besides, that is contamination of the control block. Leading failure of the control block and thus failure of the entire pump. If the control block does not clean itself leaves, it can no longer be used.

The main areas of application for this double diaphragm pump are in the promotion of high purity products in electronics general chemistry of transportation dangerous, possibly toxic media, in the nuclear sector the funding mined liquids and in the pharmaceutical industry Avoidance of contamination of pharmaceutical products te.  

The products to be funded are sol che, which must be particularly pure, for example around hydrofluoric acid, fuming nitric acid, phosphoric acid, Kö nigswasser and the like. These liquids are under an which in the manufacture of electronic components needed. They are highly corrosive, very expensive and high toxic. Therefore, mixing is required of these dangerous or difficult products with the Compressed air from the pump is prevented.

With a different air diaphragm pump, each of them is arranged two membranes, namely one Pump membrane and a drive membrane. Between the two A liquid cushion is arranged in membranes. Here only the drive diaphragm is guided, while the pump diaphragm only clamped on the circumference of the housing and is thus unguided. As a result, the pump membrane flaps uncontrollably. Because of the larger area surface of the pump membrane, its stroke is correspondingly smaller than the stroke of the drive diaphragm.

The invention has for its object a compressed air operated diaphragm pump of the type mentioned above to improve that product loss due to leakage of the Product from the pump and product contamination with Security can be avoided.

This object is achieved in that one side closed on both sides of the control block barrier chamber between two identical composite membranes provided and the barrier chamber in the area of the outside catch the composite membranes through a barrier chamber ring is limited.

In this way you get to a pump of the above mentioned type, in which a membrane rupture does not interfere in  Appearance occurs. Should the outer membrane close too Break, only that gets into the barrier chamber contained barrier medium, namely an inert material such as for example distilled water into the product or pro ducted into the barrier chamber. The barrier chamber is corrosion solid and metal free so that it does not cause corrosion or Contamination is coming. In addition, the lock chamber is very easy to clean. The slight mixing of the Product with distilled water is not special ren disadvantage because the distilled water either remain in the product or without any problem the product can be removed. If the Inner membrane, the control block only comes with the Sperrme dium in contact so that it does not cause contamination of the control section and also not to an influence solution of the medium is coming.

It is advisable to have two on both sides of the control block same composite membranes with an axial distance to each other forming a barrier chamber between the two membranes intended. - That means that both composite membranes are guided and the same movement in every respect execute gene.

The arrangement is expediently such that the Barrier chamber through the two membranes, a barrier chamber ring between the membranes in the area of the outer circumference ges of the membranes and a spacer between the mem is limited in the inner area of the membranes. - This is the distance between the two composite membranes from each other and thus the volume of the barrier chamber firmly.

In a further embodiment of the invention, the a piston arranged on the air chamber side rod extension provided on the pump chamber  side membrane is attached. - Also this ensures that both composite membranes are precisely guided and parallel to each other in every position run.

The lock chamber is useful with an incompressible Material filled. It can be a liquid act when the pump is in a temperature range un works below the boiling point of the liquid. When using the pump in a temperature range above half the boiling point of a liquid is recommended to use granules for the barrier chamber for example a polytetrafluoroethylene granulate. This The granulate expediently has a grain diameter in the range of about 1 mm.

The material for the barrier chamber can be a inert material, especially distilled, completely act salted, deionized water. - With that ensures that in the event of a rupture of the inner membrane ne contamination of the pump occurs and that at one Breakage of the outer membrane does not contaminate the product becomes.

It is recommended that the barrier chamber ring be made of transparent Material, for example made of plexiglass or quartz to ensure the proper functioning of the two Membranes can also be monitored optically.

A conductivity can be used to monitor the outer membrane sensor is provided, which came from outside through the lock merring is guided into the barrier chamber. As conductive speed sensor, two sensors can pass through the barrier chamber ring into the barrier chamber at a mutual distance be led by another. The conductivity sensor attaches intact barrier chamber the value zero. If the  Outer membrane product enters the barrier chamber and ver mixes here with the distilled water. The this increases the conductivity of the product mixture and distilled water is removed from the conductivity sor measured and on a suitable measuring device or control given device.

To monitor the inner membrane for breakage, a Capacitance sensor can be provided from the outside in the Interior of the control block is guided. If the Distilled water gets into the steering wheel block and comes into contact with the capacitance sensor. In this way, a corresponding capacity value is measured sen. The signal thus formed in the capacitance sensor is routed to a suitable isolating switch.

The invention further relates to compressed air operated double diaphragm pump with a central control block, one on each side, one on the outside Composite membrane has sealed air chamber, and

with one on each side of the control block arranged housing cheek with a pump chamber and a Pump channel in which at one end a suction valve and at another a pressure valve is arranged, and a suction neck and a pressure port between the housing wall gene, with one arranged in the pressure line of the pump Pulsation damper for smoothing the pressure on the pressure side of the pump, the pulsation damper being air chamber and a pump chamber.

Here, the invention is that between the Air chamber and the pump chamber closed to the outside barrier chamber between two identical composite membranes provided and the barrier chamber in the area of the outside catch the composite membranes through a barrier chamber ring is limited.  

This gives you the same benefits as they do are described above.

In a further embodiment of the invention, the arrangement voltage must be taken so that one in the air chamber axially displaceably mounted piston rod an air came inner membrane and spaced from it an outer membrane arranged on the product chamber side are seen, forming a barrier chamber between the membranes in the area of the outer circumference of the the barrier membrane ring is provided.

Here too, a conductivity sensor and a Ka Capacity sensor can be provided around the inner membrane and the outer membrane is breaking independently monitor.

In a further embodiment of the invention, the pump can be formed that in one of the housing cheeks outside a product chamber is provided which is connected to the pressure circuit and the product outlet of the pump is connected, and that with the product chamber of the housing cheek of the Pulsati ons damper by means of the pulsation damper locking chamber connected is.

This leads to a pump that is very compact because the pulsation damper directly on the pump housing is arranged.

The housing cheek on which the pulsation dam is attached as a common pump housing and Damper housing.

The arrangement is expediently such that the Pressure line of the pump directly into the product chamber the housing cheek opens and from the product chamber of the  Housing cheek of the product outlet out of the pump is led.

On the housing opposite the pulsation damper a support cheek is provided on the cheek. Furthermore are common continuous tie rods for the pump and the Pulsation damper provided.

The tie rods on the support cheek are on Tellerfe stored and the disc springs into the support cheek calmly. - This also ensures that with egg the least possible effort for fasteners Housing of the pump and the housing of the pulsation damper are interconnected. It is also with the help of Belleville washers possible, differences in expansion of the anchors and to compensate for the housing due to the effects of heat.

Another advantageous embodiment of the invention be is that on one in the air chamber axially ver sliding piston rod on the air chamber side arranged inner membrane and by far one per provided on the duct chamber side outer membrane are, forming a barrier chamber in the area the outer circumference of the two membranes a barrier chamber ring is provided. - This ensures that at the ends of the suction nozzle and the pressure nozzle despite different thermal expansion no leaks arise.

The invention is described below with reference to three in the Drawings shown embodiments of the vicinity ren explained. It shows

Fig. 1 is a pump right and left in the view in a section along the line II of Fig. 2,

Fig. 2 shows a section along the line II-II of Fig. 1,

Fig. 3 a section through a pulsation damper according to the line III-III of Fig. 4,

Fig. 4 on the right is a view of Fig. 3 and the left ei NEN section along the line IV-IV of Fig. 3,

Fig. 5 is a longitudinal section through the pump along the line VV of Fig. 6 and

Fig. 6 is a view of Fig. 5 partially in section.

The pump according to FIGS. 1 and 2 has a central control block 1 with Luftkam elements 2 arranged on both sides. Housing cheeks 3, 4 are provided on both sides of the control block 1 . As seen from Fig. 1 to the left, in the pump housing 4 is a pump chamber 5 is worked into. In addition, a spacer 6 with a pump channel 7 is provided in the housing cheek 4 . A valve chamber 8 with a valve 9 is arranged above the spacer 6 . Also below the spacer 6 , egg ne valve chamber 10 is provided with a valve 11 from which a pump channel 12 branches. The pump channel 12 is connected to a suction channel 13 of a suction nozzle 14 , which leads to a suction connection 15 . Similarly, a pressure channel 16 of a pressure connection 17 branches off from the valve chamber 8 and leads to a pressure connection 18 .

A locking chamber 19 is provided between the control block 1 and the side cheek 4 and is delimited by an inner membrane 20 arranged on the air chamber side, an outer membrane 21 arranged on the pump chamber side, and a locking chamber ring 22 and a spacer sleeve 23 . The inner membrane 20 is attached to a piston rod 24 . In addition, a piston rod extension 25 is provided on the inner membrane 20 , to which the outer membrane 21 is attached.

The inner membrane 20 and the outer membrane 21 are guided in parallel in all respects. Both membranes 20 , 21 are the same composite membrane in all respects. These membranes 20 , 21 are guided in parallel and run parallel to each other in every position. The barrier chamber 19 formed by the two membranes is filled with de-still, that is to say fully demineralized and fully deionized, water. The flex areas 25 , 26 of the two membranes 20 , 21 also run parallel to each other in each position.

The pump is held together by four through anchors 27 , 28 , 29 , 30 .

In the upper region of the lock chamber ring 22 , two connections 31 , 32 are provided for filling and venting the lock chamber 19 .

At the bottom of the blocking chamber ring 22, two conductivity sensors 33 , 34 are provided, which are connected to a voltage source by means of two lines 35 , 36 . In the locking chamber 19 protrude pins 37 , 38 , which are spaced from each other such that the conductivity of the medium located in the locking chamber 19 can be measured with them. When filled with distilled water barrier chamber 19 is measured with the conductivity sensors 33 , 34, the conductivity zero. If product breaks into the blocking chamber 19 due to a break in the outer membrane 21 , the conductivity sensors 33 , 34 respond. These are set to a minimum conductivity of 25 µS, but do not respond to the barrier medium. Both conductivity sensors 33 , 34 are connected in parallel to a suitable control device with a relay output for a maximum of 4 A and 250 V.

The barrier chamber ring 22 is made of plexiglass, so that the function of the two membranes 20 , 21 can also be monitored optically.

In addition, a capacitance sensor 39 is provided in the control block 1 , which registers any, even non-conductive, liquid. Of course, this means operating the pump with dry compressed air. The signal of the capacitance sensor 39 is passed to a suitable isolating switch with relay output for a maximum of 4 A and 250 V.

In FIGS. 3 and 4 Darge provides a pulsation damper, which is turned on for damping and smoothing of the pressure on the pressure side of the pump. The connection between the pressure side of the pump and the pulsation damper is made by a hose or a pipe.

The pulsation damper has a housing 40 with an air chamber 41 and a compressed air line 42nd On a Kol rod 43 an inner membrane 44 is arranged on the air chamber side. At a distance from the inner membrane 44 , an outer membrane 45 is provided per product chamber side, which is connected to the piston rod 43 by means of a piston rod extension 46 . Outside a locking chamber ring 47 and inside a locking chamber sleeve 48 is provided, a Sperrkam mer 49 is formed between the two membranes 44 and 45 and the locking chamber ring 47 and the locking chamber sleeve 48 . The air chamber 41 is separated from the pump chamber 119 by the membranes 44 and 45 .

From the outside in the blocking chamber 49 conductivity sensors 50 , 51 for monitoring the outer membrane 45 leads into it. Furthermore, a capacitance sensor 52 is guided from the outside into the air chamber for monitoring the inner membrane 44 . Otherwise, the structure and function of the barrier chamber 49 and the sensors 50 , 51 , 52 are as described in connection with FIGS. 1 and 2.

In FIGS. 5 and 6 a pump 53 is shown with attached pulsation damper 54th The central control block 55 has the air chambers 56 , 57 on both sides. An inner membrane 59 is attached to the piston rod 58 . By means of a piston rod extension 60 , an outer membrane 61 was provided with the inner membrane 59 . The inner membrane 59 and the outer membrane 61 are externally connected by a barrier chamber ring 62 and inside by a barrier chamber sleeve 63 and form the barrier chamber 64 , which is filled with distilled, demineralized, deionized water.

On the right side of the control block 55 , the housing sewange 65 is provided, in which the pump chamber 66 is arranged. A spacer 67 with a pump channel 68 is provided in the housing cheek 65 . Above the di punch 67 , a valve chamber 69 is arranged with a valve 70 . A valve chamber 71 with a valve 72 is incorporated below the spacer 67 . From here, a pump line 73 leads into a suction line 74 of the suction nozzle 75 , which mün det in the suction port 76 .

The housing cheek 65 is supported on the right in FIG. 5 by a support cheek 77 .

Likewise, on the left of the control block 55, an inner membrane 78 and at a distance from it an outer membrane 79 are provided, which are spaced apart by a barrier chamber sleeve 80 and a barrier chamber ring 81 and form a barrier chamber 82 between. In the upper region of the barrier chamber ring 81 , connections 83 , 84 are provided for filling and venting the barrier chamber 82 , while in the lower region of the barrier chamber ring 81 conductivity meters 85 , 86 are provided, which with their inner pins 85 a , 86 a into the barrier chamber 82 protrude. In addition, a capacitance sensor 87 is provided, which is guided from the outside into the interior of the center block 55 .

On the left side in Fig. 5 in the pump housing 88, a spacer 89 is provided with a pump passage 90 vorgese hen, which is in communication with the pump chamber 91. A valve 93 is provided in a valve chamber 92 above the spacer 89 . Likewise, a valve 95 is arranged below the spacer 89 in a valve chamber 94 . The pump channel 96 provided in the lower region of the housing cheek 88 is connected to the intake channel 74 of the intake port 75 .

The pressure channel 97 of the pressure port 98 opens via a transverse channel 99 into a product chamber 100 formed in the housing cheek 88 , which is separated by means of the locking chamber 103 located between the outer membrane 101 and the inner membrane 102 from the air chamber 104 of the housing 105 of the pulse damper. A conductivity sensor 108 is guided into the blocking chamber 103 through the blocking chamber ring 107 . Likewise, a capacitance sensor 109 is led into the air chamber 104 . A product outlet 120 is led out of the pump from the product chamber 100 of the housing cheek 88 . For the rest, the arrangement here is so ge, as is shown in FIGS . 1 to 4 in detail.

The pressure port 98 is sealed by means of two O-rings 110 , 111 and by means of two further O-rings 112 , 113 against the Ge cheeks 65 and 88 . Since the pressure port 98 becomes warmer than the side walls 65 , 88 when the pump is in operation, the arrangement of the O-rings 110 to 113 enables the expansion difference of the pressure port and the housing to be accommodated by the heat difference. The same also applies to the sealing rings of the suction connector 75, which are not described in detail.

Furthermore, the entire housing, consisting of the pump 53 and the pulsation damper 106 , is held together by four train anchors 114 , 115 , 116 and 117 . The tie rods are mounted on disc springs 118 , which also catches the difference in elongation during operation of the pump between the tie rods 114 , 115 , 116 , 117 and the rest of the housing.

Claims (25)

1. Compressed air-operated double diaphragm pump with a central control block, which has an air chamber closed off on both sides by a composite diaphragm, and with a housing cheek arranged on both sides of the control block with a pump chamber and a pump channel, in which at one end a suction valve and at the other end a pressure valve is arranged, and with a suction nozzle and a pressure nozzle between the housing cheeks, characterized in that on both sides of the control block ( 1 ) an outwardly closed barrier chamber ( 19 ) between two identical composite membranes ( 20 , 21 ) and the barrier chamber ( 19 ) in the area of the outer circumference of the United membrane ( 20 , 21 ) is limited by a barrier chamber ring ( 22 ). 2. Pump according to claim 1, characterized in that on both sides of the control block ( 1 ) two identical Ver bund membranes ( 20 , 21 ) with an axial distance from one another to form a barrier chamber ( 19 ) between the two membranes ( 20 , 21 ) are provided. 3. Pump according to claim 1 or 2, characterized in that the barrier chamber ( 19 ) through the two membranes ( 20 , 21 ), a barrier chamber ring ( 22 ) between the membrane ( 20 , 21 ) in the region of the outer circumference of the membrane ( 20 , 21 ) and a spacer sleeve ( 23 ) between the membranes ( 20 , 21 ) in the inner region of the membranes ( 20 , 21 ) is limited. 4. Pump according to one of the preceding claims, characterized in that on the air chamber side angeord Neten inner membrane ( 20 ) a piston rod extension ( 25 ) is provided, on which the pump chamber side is attached to an ordered outer membrane ( 21 ). 5. Pump according to one of the preceding claims, characterized in that the locking chamber ( 19 ) is filled with a compressible material. 6. Pump according to one of the preceding claims, characterized in that the locking chamber ( 19 ) is filled with a material, in particular with distilled, deionized, deionized water. 7. Pump according to one of the preceding claims, characterized in that the locking chamber ring ( 22 ) consists of transparent material, for example of plexiglass or quartz. 8. Pump according to one of the preceding claims, characterized in that a conductivity sensor ( 33 , 34 ) is provided which is guided from the outside through the locking chamber ring ( 22 ) into the locking chamber ( 19 ). 9. Pump according to one of the preceding claims, characterized in that two sen sensors ( 33 , 34 ) are guided as a conductivity sensor through the locking chamber ring ( 22 ) into the locking chamber ( 19 ) at a mutual distance from one another. 10. Pump according to one of the preceding claims, characterized in that a capacitance sensor ( 39 ) is provided which is guided from the outside into the interior of the control block ( 1 ). 11. Compressed air-operated double diaphragm pump with a central control block, which on both sides has an air chamber closed off from the outside by a composite membrane, and with a housing cheek arranged on both sides of the control block with a pump chamber and a pump channel, in which one end Suction valve and a pressure valve is arranged at the other end, as well as a suction port and a pressure port between the housing cheeks, with a pulsation damper arranged in the pressure line of the pump for smoothing the pressure on the pressure side of the pump, the pulsation damper being an air chamber and a pump chamber has, characterized in that between the air chamber ( 41 ) and the pump chamber ( 119 ) an outwardly closed barrier chamber ( 49 ) between two identical composite membranes ( 44 , 45 ) before seen and the barrier chamber ( 49 ) in the area of the outer outer circumference of the composite membranes ( 44 , 45 ) bounded by a barrier chamber ring ( 47 ) i st. 12. Pump according to claim 11, characterized in that on an in the air chamber ( 41 ) axially displaceably mounted piston rod ( 43 ) an air chamber side inner membrane ( 44 ) and at a distance from the product chamber side outer membrane ( 45 ) are provided, with formation a barrier chamber ( 49 ) between the membranes ( 44 , 45 ) in the region of the outer circumference of the two membranes ( 44 , 45 ) a barrier chamber ring ( 47 ) is provided. 13. Pump according to claim 11 or 12, characterized in that a conductivity sensor ( 50 , 51 ) is guided through the locking chamber ring ( 47 ) from the outside into the locking chamber ( 49 ). 14. Pump according to one of the preceding claims, characterized in that a capacitance sensor ( 52 ) is guided from the outside into the air chamber ( 41 ). 15. Pump according to one of the preceding claims, characterized in that the locking chamber ( 49 ) is filled with an incompressible medium. 16. Pump according to one of the preceding claims, characterized in that the locking chamber ( 49 ) is filled with an inert material, in particular with distilled water, demineralized and deionized water. 17. Pump according to one of the preceding claims, characterized in that a pulsation damper ( 54 ) is net angeord on one of the housing cheeks ( 88 ). 18. Pump according to one of the preceding claims, characterized in that in one of the housing cheeks ( 88 ) outside a product chamber ( 100 ) is provided, which is connected to the pressure connection ( 99 ) and the product outlet ( 120 ) of the pump, and that with the product chamber ( 100 ) of the housing cheek ( 88 ) of the pulsation damper ( 54 ) by means of the blocking chamber ( 107 ) of the pulsation damper ( 54 ). 19. Pump according to one of the preceding claims, characterized in that a blocking chamber ( 19 , 49 ) are provided for the pump two and for the pulsation damper ( 54 ). 20. Pump according to one of the preceding claims, characterized in that the housing cheek ( 88 ) serves as a common pump housing and damper housing. 21. Pump according to one of the preceding claims, by in that the pressure line of the pump beam directly into the product chamber (100) of the housing (88) opens and out of the product chamber (100) of the housing flange (88) of the product outlet (120) the pump is led out. 22. Pump according to one of the preceding claims, characterized in that a support cheek ( 77 ) is provided on the housing cheek ( 65 ) opposite the pulsation damper ( 54 ). 23. Pump according to one of the preceding claims, characterized in that common continuous tie rods ( 114 , 115 , 116 , 117 ) for the pump ( 53 ) and the pulsation damper ( 54 ) are provided. 24. Pump according to one of the preceding claims, characterized in that the tie rods ( 114 , 115 , 116 , 117 ) on the support cheek ( 77 ) are mounted on disc springs ( 118 ) and the disc springs ( 118 ) in the support cheek ( 77 ) are let in. 25. Pump according to one of the preceding claims, characterized in that a sealing ring ( 110 , 111 , 112 , 113 ) for the radial pressing and a sealing ring for the axial pressing are arranged on both sides of the suction nozzle ( 75 ) and on the pressure pipe ( 98 ) are.