The invention relates to a diaphragm pump of the type comprising a body which comprises:
a suction connection and a connection for discharge of the fluid to be pumped;
a suction valve and a discharge valve which are associated respectively with the suction and discharge connections;
a control chamber in which the diaphragm is disposed, and a working chamber which is situated on the side of the diaphragm opposite the control chamber;
a control pipe which can connect the control chamber to a control connection of the body, this control pipe making it possible to apply alternately partial vacuum and pressure on the diaphragm.
A diaphragm pump of this type is known in particular from WO 2012/063184 by the applicant company. The diaphragm pump is installed at the lower end of a measuring pump comprising a hydraulic motor with reciprocal motion which activates the diaphragm pump in order to inject an additive into the main current of liquid.
In a pump of this type, the diaphragm constitutes a relatively fragile component which must be able to be replaced from time to time. It is therefore desirable for the operation of removal and replacement of the diaphragm to be as simple as possible, with minimum incidence on the other components of the pump.
A diaphragm pump is also known from FR 2 313 578 with valves installed on a plate, the diaphragm being controlled by the core of an electromagnet, and not by the alternating application of partial vacuum and pressure. However in this case also, removal of the diaphragm makes it necessary to remove a plurality of components of the pump.
In addition, it is important for the design of the diaphragm pump to make it possible to reduce the dead volume which exists between the diaphragm in the position of rest, or at the start of suction, and the discharge valve, in order to facilitate the self-priming of the pump.
The objective of the invention is above all to provide a diaphragm pump which fulfils better than hitherto the aforementioned requirements, and which is simple to construct and reliable.
WO 2008/031419 relates to a diaphragm pump of the type in question, wherein the body comprises a receptacle which is open towards the exterior at one end, and is closed at its other end by a base comprising a suction orifice and a discharge orifice, the diaphragm being situated in the vicinity of the base, or against the base, and being retained by a cap which is engaged in the receptacle, this cap having, at its end which faces towards the diaphragm, a recess which constitutes the control chamber.
According to the invention, a diaphragm pump comprising the elements previously defined is characterized in that the receptacle is oriented transversely, and preferably at right-angles relative to the control pipe, the recess which constitutes the control chamber is connected to a passage which opens onto the lateral surface of the cap, in order to establish communication with the control pipe, and the cap is retained in place in the receptacle by a ring, which is connected, in particular by means of a thread, to the body of the pump, and comprising a means for retention of the cap.
In a pump of this type, the cap can be removed by simple translation after removal of the ring which retains this cap, thus making it possible to access the diaphragm and replace it if necessary without needing to intervene on the other elements of the pump. The cap is put into place by means of a simple translation movement.
Preferably, the pump comprises a valve device which comprises a plate in which the suction valve and the discharge valve are fitted, with the plate supporting the diaphragm, and being retained against the base of the receptacle by the cap.
The assembly of the valves installed on the plate, and of the diaphragm, constitutes an interchangeable device which can be withdrawn after removal of the cap, and replaced by a new assembly without intervention on the other components of the pump.
A suction orifice and a discharge orifice are provided in the base of the receptacle opposite the corresponding valves which are supported by the plate. A sealing ring which is fitted on the plate around each valve is designed to ensure the sealing between the plate and the pump body. At least one channel for flow of the fluid passes through the plate at the suction and discharge orifices. Preferably, a single channel is provided at the discharge orifice, in order to reduce the dead volume between the diaphragm and the discharge valve.
The plate can be snapped onto the end of the cap, in particular by means of resilient lugs which are provided on the cap.
The suction and discharge valves are advantageously constituted by valves of the umbrella type with a core engaged in an orifice in the plate, and a flexible flange or cover which closes the channel(s) which pass(es) through the plate. The valves can be in contact with the diaphragm when the pump is at rest or at the end of discharge, such that the dead volume between the diaphragm and the discharge valve is minimum. As a variant, the suction and discharge valves could be constituted by valves in the form of a duckbill comprising two flexible lips which are applied against one another according to a configuration in the form of a “V”, the tip of which faces in the direction of flow of the fluid.
Also as a variant, the suction and discharge valves of the umbrella type or in the form of a duckbill can be disposed in receptacles in the pump body, and the diaphragm is applied directly against the base of the receptacle, without being disposed on a plate.
The angle which is formed between the geometric axes of the suction and discharge connections is preferably more than 90°, and in particular equal to 135°. Advantageously, the geometric axis of the suction connection is parallel to the geometric axis of the control pipe, whereas the geometric axis of the discharge connection forms an angle of 45°, or close to this value, with the geometric axis of the control pipe.
The cap can have a surface comprising a cylindrical part and a frusto-conical part which can be applied against a conjugated frusto-conical surface of the receptacle, with the passage provided in the cap for connection to the control pipe opening in this frusto-conical part, and being opposite the control pipe, and a means for polarization being provided on the lateral surface of the cap in order to cooperate with a means for polarization which is conjugated with the receptacle, in order to ensure the appropriate positioning of the passage relative to the control pipe.
The means for polarization can be constituted by a rib which is provided on the lateral surface of the cap in order to cooperate with a corresponding groove provided in the receptacle.
The sealing of the connection between the passage of the cap and the control pipe is advantageously ensured by a sealing ring, in particular an O-ring seal, which surrounds the output of the passage on the frusto-conical oblique surface.
This ring is preferably accommodated in a circular groove provided in the oblique surface of the cap. This arrangement with an oblique surface makes it possible to reduce the risk of damaging the sealing ring, in particular by pinching, during the fitting and the engagement in translation of the cap in the receptacle.
Advantageously, the passage which is provided in the cap in order to connect the control chamber to the control pipe extends along a length which is longer than the radius of the cap, in order to reduce the risk of interruption of the suction by adhesion of the diaphragm against the base of the control chamber.
The invention also relates to a valve device for a diaphragm pump as previously defined, comprising a plate in which there are fitted a suction valve and a discharge valve, in particular valves which have a cover in the form of an umbrella and a core which is accommodated in an orifice in the plate, said plate supporting a diaphragm. This valve device constitutes an interchangeable assembly for a diaphragm pump.
A diaphragm pump according to the invention is advantageously installed in the lower part of a proportional metering device such as described in WO 2012/063184, comprising a metering device body with a main liquid input and an output, a hydraulic motor which is accommodated in the body and is activated by the main liquid, the motor driving a plunger piston which ensures suction during an outward course which is transmitted by the control pipe to the control chamber of the diaphragm pump, and a discharge, which thrusts the diaphragm when the plunger piston carries out a return course.
A proportional metering device of this type, functioning without electricity, permits injection of auxiliary liquid supplied by the diaphragm pump.
Advantageously, for the retention of the pump on the metering device, the control connection of the diaphragm pump comprises a clamp which snaps onto the connection, and a means for connection to the metering device, in particular a nut, which is retained axially by said clamp.
In addition to the above-described arrangements, the invention consists of a certain number of other arrangements which will be described explicitly hereinafter with reference to embodiments described in relation to the drawings which are appended, but are in no way limiting. In these drawings:
Similarly to
Similarly to
A suction valve 4 and a discharge valve 5 are associated respectively with the suction 2 and discharge 3 connections.
The diaphragm M is disposed in a control chamber 6, which is connected by a passage 7 to a control pipe 8, which makes it possible to apply alternately partial vacuum and pressure in the chamber 6 and on the diaphragm M. The pipe 8 is provided in a control connection 9.
The geometric axes of the connections 2, 3 and 9 and their respective pipes are situated on the same plane. Preferably, the pump P is used in the position represented in
A working chamber 10, which can be seen in
The body 1 comprises a receptacle 11 which is oriented transversely, and preferably at right angles relative to the control pipe 8. This receptacle 11 is provided in a cylindrical protuberance 12 of the body 1, on the side opposite the discharge connection 3. The receptacle 11 is open at one end towards the exterior, and is closed at its other end by a base 13 comprising a suction orifice 14 which is connected to the pipe of the suction connection 2, and a discharge orifice 15 which is connected to the pipe of the discharge connection 3.
The diaphragm M is situated in the vicinity of the base 13, and is retained by a cap 16 which is engaged by translation, without movement of rotation, in the receptacle 11.
The control chamber 6 is provided at the inner end of the cap 16 in the form of a dish which widens in the direction of the diaphragm M. The passage 7 extends orthogonally to the geometric axis of the cap 16, along a length which is greater than the radius of the cap 16, this passage 7 opening onto the lateral surface of the cap, in the alignment of the control pipe 8.
The cap 16 is retained in position by a ring 17 which is connected to the protuberance 12 of the pump body, advantageously by a thread, in which case the ring 17 constitutes a nut. Other means for connection of the ring 17 to the protuberance 12 could be provided, for example, in the form of ramps inclined as a helix.
At its end which is distant from the diaphragm M, the ring 17 comprises a flange 18 which projects radially towards the interior, and constitutes a means for retention of the cap 16, which comprises a peripheral rib 19 which cooperates with the flange 18. The receptacle 11 comprises a frusto-conical intermediate part 20 in the vicinity of the diaphragm M, and the diameter of which decreases in the direction of this diaphragm.
The cap 16 has a conjugated frusto-conical part 21 which is applied against the part 20 during the clamping of the cap 16 by the ring 17.
In order to ensure correct positioning of the cap 16 in the receptacle 11, so that the passage 7 is in the alignment of the pipe 8, means for polarization are provided between the cap 16 and the receptacle 11, in order to impose the engagement of the cap in the appropriate position. As can be seen in
The sealing between the cap 16 and the body 1 at the output of the passage 7 is advantageously provided by means of a sealing ring 23, in particular an O-ring seal, which in particular is made of elastomer material, accommodated in a groove 24 provided in the oblique surface of the frusto-conical part. This arrangement of the seal 23 on an oblique surface makes it possible to reduce, or even eliminate, the risk of pinching of the seal during the fitting by translation of the cap 16 in the receptacle 1 at the pipe 8.
According to the embodiment in
At least one channel 26, 27 passes through the plate in the area which is covered by the cover of the valve. As can be seen better in
The plate 25 supports the diaphragm M which has on its periphery a rim 28 which is received partly in a peripheral throat in the plate 25, and also partly in a peripheral throat at the end of the cap 16, surrounding the control chamber 6. The diaphragm M comprises a thicker central part 29, which is connected by an annular ring 30 to the rim 28. When it is at rest at the end of discharge, the ring 30 has a cross-section in the form of an arc of a convex curve on the valve side. In this position of rest of the diaphragm, the suction valve 4 is in contact by means of its cover in the form of an umbrella with the diaphragm M, whereas the core of the discharge valve 5 is in contact with the ring 30, such that the dead space between the diaphragm and the valve is reduced to a minimum.
The sealing between the plate 25 and the base of the receptacle around the orifices 14 and 15 is ensured by means of sealing rings 31, 32, in particular O-ring seals made of elastomer material, accommodated in annular throats provided in the plate 25, in order to surround the valves and the orifices 14, 15. The device which is formed by the plate 25, the valves 4 and 5 and the diaphragm M constitutes an interchangeable assembly which can easily be removed and replaced, after removal of the cap 16 and extraction in translation towards the left according to
The decrease in, or even elimination of, the dead volume between the diaphragm M and the valves, in particular the discharge valve 5, permits self-priming of the diaphragm pump.
This fitting on a plate, with lateral introduction into the receptacle 11, with fitting and clamping of the diaphragm by means of the cap 16 and a ring-nut 17, amply simplifies the fitting.
Advantageously, as illustrated in
The embodiment according to
The plate 25 can easily be made available in different materials, and in particular in materials containing fluorine in order to prevent deposits and to improve the chemical resistance. The plate 25 can also be made of ceramic in the case of products to be pumped which would have an abrasive nature.
The valves 4, 5 made of elastomer material permit versatility of design by changing the materials, in particular in order to resist oxidizing products with a high level of chlorine.
A suction phase corresponds to the ascending course according to
The discharge connection 3 is connected by means of a flexible pipe 42 to a transverse extension 43, which faces vertically downwards, of the connection 39. The inclination at 45°, or according to an angle close to this value, of the geometric axis of the connection 3 relative to the geometric axis of the pipe 8, makes it possible to provide the pipe 42 with a simple form comprising a straight part followed by an arc of a curve with a large radius of curvature for the branching on the extension 43.
Similarly to
According to this variant, the suction and discharge valves 4a, 5a are in the form of a duckbill, i.e. in the form of an inverted “V” for the suction valve 4a, and inclined for the discharge valve 5a. The tip of the valves in the form of a “V” is oriented in the direction of flow of the liquid. These valves comprise flexible lips which are applied against one another in order to form the inverted or inclined “V”, and permit passage of the liquid obtained from the concavity of the “V”, and prevent circulation in the inverse direction.
According to a variant not represented, the valves 4a, 5a in the form of a duckbill can be fitted on a plate similar to the plate 25 in
According to the variant in
According to this variant, at the end of discharge or in the position of rest of the pump, the diaphragm M is applied directly against the base 13a of the receptacle in the pump body.
The cap 16a, which is similar to the cap 16 in
The functioning of the variant Pa in
When a partial vacuum is created in the control pipe 8, the diaphragm M is deformed towards the left in
When the pressure increases in the pipe 8, the diaphragm M is thrust to the right according to
Similarly to
In the vicinity of its free end on the periphery, the connection 9 comprises a throat 48 in which there is fitted a sealing ring 49, in particular an O-ring seal. As can be seen in
A nut 50 is fitted such as to be free in rotation around the connection 9. The nut 50 is retained according to the axial direction by an open clamp 51 comprising a receptacle substantially in the form of a “U” with narrowed ends. The clamp 51, which can be made of plastic material, has a certain resilience in order to snap into a groove 52 in the outer wall of the connection 9. The groove 52 has two diametrically opposed flattened parts 53 against which the branches of the “U” of the clamp 51 are applied after being put into place. The clamp 51 has a circular outer edge, and constitutes a means for axial retention of the nut 50. This nut comprises a flange 54 which projects radially towards the interior and can abut the clamp 51. The nut 50 can be displaced in translation at the rear of the clamp 51.
The lower end of the metering device J comprises on its periphery a thread on which the nut 50 is screwed for retention of the pump P on the metering device J. This structure makes it possible to produce easily a sealed rotary connection 9 with a single sealing ring.
Irrespective of the embodiment adopted, the fitting and removal of the diaphragm M are carried out rapidly and simply, without needing to intervene on the other elements of the pump. The priming of the pump is facilitated by the reduction of the dead volume between the diaphragm and the valves, in particular the discharge valve.
Number | Date | Country | Kind |
---|---|---|---|
13 60587 | Oct 2013 | FR | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/IB2014/065636 | 10/27/2014 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2015/063668 | 5/7/2015 | WO | A |
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2383193 | Herbert | Aug 1945 | A |
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20130233421 | Furet et al. | Sep 2013 | A1 |
Number | Date | Country |
---|---|---|
1 971 774 | Sep 2008 | EP |
2 313 578 | Dec 1976 | FR |
S60-105936 | Jun 1985 | JP |
2007080249 | Jul 2007 | WO |
2008031419 | Mar 2008 | WO |
2010132372 | Nov 2010 | WO |
2012063184 | May 2012 | WO |
Entry |
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International Search Report, dated Mar. 3, 2015, from corresponding PCT Application. |
Number | Date | Country | |
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20160305424 A1 | Oct 2016 | US |