The invention relates to a diaphragm pump having a pump housing on which a disposable cell is releasably fixable, which disposable cell has a first and a second cell wall which define an operating space between them, and having an operating diaphragm which is drivingly connected to an oscillating stroke drive and which is releasably coupleable with the flexible first cell wall on its diaphragm flat side remote from the stroke drive.
Diaphragm pumps for the conveying and metering of liquids are used in very diverse realizations. High demands are placed on such diaphragm pumps in particular in the case of applications in the health and research sectors.
In order to avoid cross contaminations from various fluids, clean and often sterile fluid paths are mandatory. In order to guarantee the cleanliness and sterility of the fluid paths in the previously known diaphragm pumps, said diaphragm pumps have to be cleaned or even sterilized in an expensive and time-consuming manner. Said cleaning and sterilizing processes often pose great challenges to the users as in particular the expenditure on quality control is linked to enormous expense, effort and uncertainty. The latter has to be constantly monitored by way of additional checks and random sampling and reduced to a minimum. The expense and effort required for cleaning and sterilizing can make the costs connected with the operation of such diaphragm pumps soar. The interruptions in the production or research process generated thereby are unwanted and should be able to be reduced to a minimum.
One efficient method to be able to exchange the fluid-conducting path of a pump system in a short time and at the same time ensure that the entire pump system is clean and, where applicable, even sterile when it is ready for use, is provided by the use of quick change components such as, for example, hoses, fittings and the fluid-conducting components of the pump head of a diaphragm pump.
The market already provides a wide selection of hoses and accessories which are available as disposable components.
EP 0 307 069 B1 has already disclosed a diaphragm pump of the type mentioned in the introduction where the fluid-conducting components of the diaphragm pump are provided in a quick-change disposable or single-use cell. To this end, the disclosed diaphragm pump has a pump housing on which the disposable cell is releasably fixable. Said disposable cell comprises a first and a second cell wall which define an operating space between them. The disclosed diaphragm pump comprises an operating diaphragm which is drivingly connected to an oscillating stroke drive. Said operating diaphragm is releasably coupleable with the flexible first cell wall on its diaphragm flat side remote from the stroke drive. In this case, one of the realizations of the disclosed diaphragm pump shown in EP 0 307 069 B1 provides that the dead space arranged between the operating diaphragm and the first cell wall is connected by means of an outlet line, which is guided right through the operating diaphragm, to a non-return valve arranged outside the diaphragm pump. Said non-return valve does allow air compressed between the operating diaphragm and the first cell wall to flow out, but at the same time prevents air flowing back into the dead space remaining between the operating diaphragm and the first cell wall. Consequently, the first cell wall of the disposable cell and the operating diaphragm are held against one another and coupled together as a result of negative pressure or as a result of adhesive forces. As the outlet line, which is guided through the operating diaphragm and extends up to the non-return valve arranged outside the disclosed diaphragm pump, is comparatively long, a certain residual volume of air always remains in said outlet line which expands again during intake and can pass into the dead space arranged between the operating diaphragm and the first cell wall. As a result, not all the volume generated by the operating diaphragm is sucked into the operating space arranged between the cell walls of the disposable cell, which reduces the efficiency and the accuracy of the diaphragm pump disclosed in EP 0 307 069 B1 and can also result in said diaphragm pump no longer being able to prime itself The capacity of the pump to self-prime is, however, a substantial advantage of diaphragm pumps compared, for example, to centrifugal pumps.
In the case of the diaphragm pump mentioned in the introduction, one of the objects consequently includes creating a diaphragm pump where the dead volume in the dead space between the operating diaphragm and the flexible first cell wall is as small as possible or practically zero.
The solution according to the invention to said object provides in the case of the diaphragm pump of the type mentioned in the introduction in particular in that at least one outlet port in the operating diaphragm is provided with a return flow obstructer or return flow preventer arranged inside the operating diaphragm for evacuating the dead space arranged between it and the first cell wall.
The diaphragm pump according to the invention has an operating diaphragm which comprises a return flow obstructer or return flow preventer inside the at least one outlet port arranged in the operating space. The operating diaphragm, which is separated from the fluid-conducting operating space by the first cell wall of the disposable cell which serves as a blocking diaphragm, is displaced by the oscillating stroke drive into the suction stroke and the pressure stroke. In this case, the first cell wall of the disposable cell, which serves as a blocking diaphragm, lies directly on the surface of the operating diaphragm and fits snugly to the diaphragm surface of the operating diaphragm. During the pressure stroke, the flexible first cell wall is expanded toward the top dead center as a result of the upward movement of the operating diaphragm, which is why, through the tensile stress generated, it is able to abut in an optimum manner against the surface of the operating diaphragm. So that the first cell wall is able to abut in an optimum manner against the diaphragm surface of the operating diaphragm, the air remaining in the dead space located in between has to be able to be displaced or removed. For this reason, there is at least one outlet port in the operating diaphragm, in which outlet port a return flow obstructer or return flow preventer is interposed inside the operating diaphragm. Whilst the return flow obstructer delays the air flowing into the dead space arranged between the operating diaphragm and the first cell wall again, the flowing of air into the dead space again is efficiently prevented by a return flow preventer. As a result, negative pressure, which couples said two flexible components of the diaphragm pump according to the invention to one another, is generated between the first cell wall and the operating diaphragm. Due to the negative pressure generated in the dead space, the first cell wall remains abutting against the operating diaphragm during the suction stroke of said operating diaphragm. Actively pumping out the dead space arranged between the operating diaphragm and the first cell wall is not absolutely necessary. As in the case of the diaphragm pump according to the invention, the non-return valve is not arranged outside the diaphragm pump, but rather inside the operating diaphragm, the dead volume remaining between the dead space and the non-return valve can be kept comparatively small. The diaphragm pump according to the invention is consequently characterized by a high degree of efficiency and a functionally reliable operation.
In order to be able to seal the operating space in the disposable cell in a proficient manner in relation to the surrounding air, it is advantageous when the first cell wall is clamped between the operating diaphragm and the second cell wall in an edge region which defines the operating space.
The handling of the diaphragm pump according to the invention as well as the assembly and disassembly of the disposable cell associated therewith is made considerably easier when the first and the second cell wall are connected together so as to be fluid-tight in an edge region which defines the operating space.
So that the operating diaphragm is able to transmit its downward movement into the bottom dead center in a proficient manner onto the first cell wall of the disposable cell during the suction stroke, it is advantageous when the first cell wall abuts flatly against the operating diaphragm during the downward movement of the operating diaphragm to the bottom dead center.
In order to be able to couple the operating diaphragm and the first cell wall of the diaphragm pump according to the invention with one another in a proficient manner, it is advantageous when that the first cell wall is releasably coupleable with the operating diaphragm by means of negative pressure. In addition to this or instead of it, it can be expedient when the first cell wall is releasably coupleable with the operating diaphragm by means of adhesion.
Accordingly, a further embodiment according to the invention provides that the first cell wall is releasably coupleable with the operating diaphragm by means of prestressing and that, for this purpose, the first cell wall comprises its own elasticity which prestresses the first cell wall in the direction of the operating diaphragm.
In order to delay in a noticeable manner surrounding air flowing again into the dead space arranged between the operating diaphragm and the first cell wall, it is advantageous when the return flow obstructer provided in the at least one outlet port is developed as a nozzle or as a narrowing of the cross section in the outlet port which is restricted to the operating diaphragm. Whilst the air still remaining initially in the dead space is pressed rapidly out through the outlet port during the pressure stroke of the diaphragm pump according to the invention, the surrounding air flowing into the dead space again during the suction stroke of the operating diaphragm is considerably delayed.
Instead of a return flow obstructer in the operating diaphragm, a preferred further development according to the invention provides that the return flow preventer provided in the at least one outlet port is developed as a non-return valve which is movable from a closed position against a restoring force into the open position which opens in the direction opposite the dead space.
In this case, it is expedient when the return flow preventer has a valve body which is movable between the open position and closed position.
An embodiment according to the invention which is particularly simple in design and production provides that the valve body of the return flow preventer is connected integrally to the elastic material of the operating diaphragm.
A particularly structurally simple embodiment according to the invention consists in that that the return flow preventer is realized as a duckbill valve or as a flutter valve.
In the case of a corresponding arrangement of the diaphragm pump according to the invention, it can be advantageous when the valve body of the return flow preventer remains in its closed position during the downward movement of the operating diaphragm to the bottom dead center due to its mass inertia and is moved into the open position during the stroke movement toward to the top dead center.
It is advantageous when the restoring force acting on the valve body is applied by at least one resiliently elastic or rubber-elastic restoring element or by the own elasticity of the valve body.
In order to be able to vary the restoring force where necessary, it is advantageous when the at least one restoring element is realized as a compression spring.
A proven and particularly simple embodiment according to the invention provides that the stroke drive is realized as an eccentric drive.
However, it is also possible for the stroke drive to be realized as a linear drive. In this case, the stroke drive can be realized as an electric or hydraulic stroke drive.
A further development according to the invention provides that the stroke movement of the stroke drive into the top dead center is effected by means of at least one lifting magnet and the downward movement of the operating diaphragm into the bottom dead center is effected by means of a resiliently elastic or rubber-elastic restoring part. However, an embodiment where the stroke movement of the stroke drive into the top dead center is effected by means of a resiliently elastic or rubber-elastic restoring part and the downward movement of the operating diaphragm into the bottom dead center is effected by means of at least one lifting magnet is preferred.
An easily handleable embodiment according to the invention provides that the second cell wall is formed by at least one part region of the side wall facing the first cell wall of a dimensionally stable component of the disposable cell.
In this case, the dimensionally stable component of the disposable cell can be formed by a single-part or multiple-part plastics material block. Such a plastics material block can be produced in a cost-efficient manner at comparatively low expense.
In order to ensure the design and production of a functionally reliable embodiment of diaphragm pump according to the invention, it is advantageous when the dimensionally stable component has two interconnected part elements which the pump inlet and the pump outlet penetrate and that the at least one inlet valve and the at least one outlet valve are provided in the separating plane of the part elements.
The simple design and production of the diaphragm pump according to the invention is promoted when the at least one inlet valve and/or the at least one outlet valve is/are realized as (a) flutter valve(s).
In order to promote consistent pump operation of the diaphragm pump according to the invention, it is advantageous when at least one pulsation damper is provided in the disposable cell in the pump inlet and/or in the pump outlet. In this case, a preferred embodiment according to the invention provides that the at least one pulsation damper is realized as at least one compensating diaphragm which is interposed in the pump inlet and/or the pump outlet.
In the case of the diaphragm pump of the type mentioned in the introduction, a further object includes in particular in creating a diaphragm pump which is distinguished by particularly simple handling.
The solution according to the invention to said object provides in the case of the diaphragm pump of the type mentioned in the introduction in particular in that the disposable cell is releasably fixable on the pump housing without any tools by means of a clamping device.
In the case of the diaphragm pump according to the invention, the disposable cell which comprises the fluid-conducting operating space is releasably fixable on the pump housing without any tools by means of a clamping device.
As the disposable cell is able to be releasably fixed on the pump housing without any tools, the disposable cell can also be releasably fixed on the pump housing by a user who has not receiving any technical training.
In this case, a preferred further development according to the invention provides that the clamping device has a pivot lever which is held on the pump housing so as to be pivotable and is movable between a release position and a hold position. Such a pivot lever which is held on the pump housing so as to be pivotable and is movable between a release position and a hold position is also solely actuatable in a manual manner.
It is particularly advantageous when the pump housing is developed in a divisible manner and has at least two housing parts, between which the disposable cell is releasably clampable. Many applications demand a high level of cleanliness and, where applicable, even of sterility as well as a high level of safety with regard to a threatening cross contamination of fluids. In the case of non-exchangeable system components, time-consuming cleaning and, where applicable, sterilizing processes have to be carried out on the pump system before a next process step can be effected. The carrying out of such cleaning and sterilizing processes is time-intensive and requires an extensive system know-how. Uncertainty as regards parts that are possibly still unclean persists nevertheless after every cleaning process.
In order to be able to couple the disposable cell quickly and with little effort to the operating diaphragm of the diaphragm pump according to the invention located in the pump housing, it is advantageous when the housing parts are movable by means of the clamping device between a holding position where they are brought closer together and a release position where they are correspondingly spaced apart from one another.
A preferred embodiment according to the invention provides that a first housing part, which receives the stroke drive therein, and a second housing part, which is developed as a cover of the diaphragm pump, are provided.
A preferred further development according to the invention provides that the second housing part has a recess into which the disposable cell is insertable in a positive-locking manner. In order to prevent the disposable cell from bursting when the clamping device is opened into the release position, it advantageous when the disposable cell protrudes into the recess for as long as there is overpressure in the operating space.
In order to be able to couple the operating diaphragm and the first cell wall of the disposable cell together always in a positionally correct manner, it is advantageous when positioning aids, which secure an established relative position between the first housing part and the disposable cell, are provided between the first housing part and the disposable cell. A preferred embodiment where the clamping device is securely fixed in the hold position provides that the pivot lever of the clamping device is developed as a toggle lever. In this case, a preferred embodiment consists in that the pivot lever, which is realized as a toggle lever, is held in a self-locking pivot position above the dead point of the toggle lever mechanism in the holding position of the clamping device.
The pivot lever can be additionally secured in the hold position of the clamping device when the pivot lever is movable from the hold position into the release position of the clamping device against the restoring force of at least one resiliently elastic or rubber-elastic restoring element.
The pivot lever can also be secured particularly well in the hold position of the clamping device when the pivot lever is pivotable about a pivot axis which is realized as an eccentric.
The clamping device is capable of holding the disposable cell in a particularly proficient manner on the pump housing when the pivot lever is developed in a bow-shaped manner and clamps or fixes the disposable cell on the pump housing with the cross web of the bow form in the hold position of the clamping device.
A further development according to the invention which is worthy of protection in its own right provides that the diaphragm pump has a pump control means, and that a data storage unit, which interacts with a reader unit in the region of the pump housing, which reader unit communicates in a control manner with the pump control means, is provided on the disposable cell for storing specific data of the disposable cell.
In this case, preferred embodiments according to the invention provide that the data storage unit and the reader unit interact with one another in a wired or wireless manner.
Further developments according to the invention are produced from the following description in conjunction with the claims as well as the drawing. The invention is described in more detail below by way of preferred exemplary embodiments of the diaphragm pump according to the invention, in which:
Each of the disposable cells 2 comprises a first and a second cell wall 3 or 4 which defines an operating space 5 between them. An operating diaphragm 6, which is drivingly connected to an oscillating stroke drive and which is releasably coupleable with the flexible first cell wall 3 on its diaphragm flat side remote from the stroke drive, is provided in the pump housing 2 of the diaphragm pumps 101, 102, 107, 109, 116 and 123. In this case, each disposable cell 2 of the diaphragm pumps 101, 102, 107, 109, 116 and 123 comprises a pump inlet 7, which opens out in the operating space 5 and has at least one inlet valve 8, and a pump outlet 9 which is connected to the operating space 5 and has at least one outlet valve 10. A suction stroke and a pressure stroke are carried as a result of the oscillating movement of the operating diaphragm 6. In contrast to conventional diaphragm pumps, the operating diaphragm 6, in this case, is not in direct contact with the fluid to be conveyed. Rather, the operating diaphragm 6, for instance at the largest diameter of the operating space 5, is hermetically separated from the fluid-conducting operating space 5 by a flexible and film-like first cell wall 3 of the disposable cell, which serves as a blocking diaphragm. Due to its arrangement in the pump head, the first cell wall 3, which serves as a blocking diaphragm, rests flatly directly on the surface of the operating diaphragm 6 and fits snugly to the surface of the diaphragm of the operating diaphragm 6. During the pressure stroke, the first cell wall is expanded by the upward movement of the operating diaphragm 6, which is why it is able to abut optimally against the diaphragm surface of the operating diaphragm 6 as a result of the tensile stress generated. The air which initially still remains in the dead space 11 arranged between the operating diaphragm 6 and the first cell wall 3 is able to flow out through an outlet port 12 which is arranged in the operating diaphragm 6 and is restricted to the cross section of the operating diaphragm 6. To evacuate the dead space 11 which is arranged between the operating diaphragm 6 and the first cell wall 3 of the disposable cell 2, the outlet port 12 in the operating diaphragm 6 is provided with a return flow obstructer or a return flow preventer 13.
In the case of the diaphragm pumps 101, 102, 107, 109, 116 and 123 shown here, a return flow preventer 13 is provided which only allows fluid to flow out of the dead space 11, whilst, in contrast, surrounding air or similar fluid is prevented from flowing into the dead space 11 again.
In the hold positions of the disposable cell 2 on the pump housing 1 shown in
Once the disposable cell 2 has been placed on the pump housing 1, air possibly remaining in the dead space 11 is able to escape through the outlet port 12 provided in the operating diaphragm 6, whilst, in contrast, air flowing into the dead space 11 is at the same time prevented or at least delayed. As a result, negative pressure, which couples the operating diaphragm 6 and the first cell wall 3 to one another and holds them together in a flat manner, is generated between the operating diaphragm 6 and the first cell wall 3. Thanks to the negative pressure generated as a result, the first cell wall 3 of the disposable cell 2 remains abutting against the operating diaphragm 6 during the suction stroke. An additional vacuum pump or an active external vacuum generating means is not absolutely necessary in order to generate the necessary negative pressure in the dead space 11 between the operating diaphragm 6 and the first cell wall 3.
As the first cell wall 3 abuts flatly against the operating diaphragm 6 during the downward movement of the operating diaphragm 6 toward the bottom dead center, the first cell wall 3 is preferably releasably coupleable here with the operating diaphragm 6 by means of negative pressure or by means of adhesion.
In the case of the realizations 101, 102, 107, 109, 116 and 123 of the diaphragm pump shown here, the return flow preventer 13 provided in the at least one outlet port 12 is realized as a non-return valve which is movable from a closed position against a restoring force into the open position which opens in the direction opposite the dead space 11.
The return flow preventer 13, which is developed as a non-return valve, has a valve body which is movable between the open and the closed position for this purpose. In the case of the diaphragm pump 106 shown in
In this case, the data storage unit 32 and the reader unit 33 interact with one another in a wired or wireless manner.
In the case of the diaphragm pump 107 shown in
The diaphragm pumps 101, 102, 109, 116 and 123 comprise, in contrast, a non-return valve which is realized as a flutter valve 17. The valve body of said flutter valve 17 which is shown in
The stroke drive of the diaphragm pumps 101, 107, 109 and 123 is realized as an oscillating linear drive 18. Said stroke drive which is realized as a linear drive 18 could be developed as an electric or hydraulic stroke drive. However, it is also conceivable for the stroke movement of the stroke drive into the top dead center to be brought about by means of at least one lifting magnet and the downward movement of the operating diaphragm 6 into the bottom dead center to be brought about by means of a resiliently elastic or rubber-elastic restoring part. However, an embodiment where the stroke movement of the stroke drive into the top dead center is brought about by means of a resiliently elastic or rubber-elastic restoring part and the downward movement of the operating diaphragm 6 into the bottom dead center is brought about by a lifting magnet is preferred.
The stroke drive of the diaphragm pump 102, in contrast, is realized as an eccentric drive 19. Said eccentric drive 19 comprises a connecting rod 20, which is connected in an articulated manner to the operating diaphragm 6 and is mounted 6 so as to be rotatable on an eccentric 21 by way its connecting rod end remote from the operating diaphragm in such a manner that the rotation of the eccentric 21 is converted into an oscillating linear movement of the operating diaphragm 6.
It is particularly easy to see in
In order to homogenize the fluid conveying of the diaphragm pumps 101, 102, 107, 109, 116 and 123 shown here, it is expedient when at least one pulsation damper—not shown here in any detail—is provided in the disposable cell 2 in the pump inlet 7 and/or in the pump outlet 9. Said pulsation damper can be realized as at least one compensating diaphragm which is interposed in the pump inlet 7 and/or the pump outlet 9. It can be seen in
Whilst the first housing part 25 receives the stroke drive within itself, the second housing part 26 is developed as a cover. A recess 27, into which the disposable cell 2 is insertable in a positive-locking manner, is provided in said second housing part 26. In this case, the disposable cell 2 protrudes into the recess 27 for as long as there is negative pressure in the operating space 5. Positioning aids, which secure a fixed relative position between the first housing part 25 and the disposable cell 2, are provided between the first housing part 25 and the disposable cell 2. Said positioning aids can be formed by positioning journals 28 which protrude on the first housing part 25 or on the disposable cell 2 and protrude in positioning recesses in the respectively other component 2, 25.
For inserting the disposable cell 2, the clamping device has to be open and be situated in its release position, in which release position the position description “off” can be seen on the cross web of the bow-shaped pivot lever 24. In this case, the disposable cell 2 is placed onto a pre-positioning surface 31 and pushed into the opening that is formed between the housing parts 25, 26 in the release position. In said release position, the second housing part 26, which serves as a cover, is at a sufficient spacing from the first housing part 25, which includes the stroke drive, such that the disposable cell is able to be pushed in transversely with respect thereto. The pivot lever 24 of the clamping device is then pivoted from the “off” position toward the “on” position. As can be seen in
It can be seen in
In the case of the realization 216 of the clamping device shown in
The clamping device 223 shown in
1 Pump housing
2 Disposable cell
3 First cell wall
4 Second cell wall
5 Operating space
6 Operating diaphragm
7 Pump inlet
8 Inlet valve
9 Pump outlet
10 Outlet valve
11 Dead space
12 Outlet channel
13 Return flow preventer
14 Valve ball
15 Duckbill valve
16 Duckbill-shaped valve body
17 Flutter valve
18 Linear drive
19 Eccentric drive
20 Connecting rod
21 Eccentric
22 First part element
23 Second part element
24 Pivot lever
25 First housing part
26 Second housing part
27 Recess
28 Positioning journal
29 (Eccentric) pivot axis
30 Restoring element
31 Pre-positioning surface
32 Data Storage Unit
33 Reader Unit
101 Diaphragm pump (according to
102 Diaphragm pump (according to
106 Diaphragm pump (according to
107 Diaphragm pump (according to
109 Diaphragm pump (according to
116 Diaphragm pump (according to
123 Diaphragm pump (according to
209 Clamping device (according to
216 Clamping device (according to
223 Clamping device (according to
Number | Date | Country | Kind |
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10 2014 013 779 | Sep 2014 | DE | national |
Number | Name | Date | Kind |
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4468222 | Lundquist | Aug 1984 | A |
4560326 | Seki | Dec 1985 | A |
4594059 | Becker | Jun 1986 | A |
4634430 | Polaschegg | Jan 1987 | A |
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7503910 | Adahan | Mar 2009 | B2 |
8192401 | Morris | Jun 2012 | B2 |
20030217962 | Childers | Nov 2003 | A1 |
20080181800 | Muschalek | Jul 2008 | A1 |
Number | Date | Country |
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3438982 | May 1985 | DE |
0307069 | Jul 1992 | EP |
Number | Date | Country | |
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20160076529 A1 | Mar 2016 | US |