US20110135514A1

US20110135514A1 - Pump Device

Info

Publication number: US20110135514A1
Application number: US13/058,904
Authority: US
Inventors: Christian Huhnke; Henning Ladiges
Original assignee: SPX Flow Technology Norderstedt GmbH
Current assignee: SPX Flow Technology Germany GmbH
Priority date: 2008-08-14
Filing date: 2009-08-14
Publication date: 2011-06-09
Also published as: CN102124226A; DK200800165U3; EP2329147A2; WO2010017997A3; CN102124226B; WO2010017997A2; PL2329147T3; ES2773043T3; BRPI0917663A2; EP2329147B1; EP2154371A1; EP2154371B1

Abstract

A pump device includes a pulsator as a drive element for a main pump head which is situated in a delivery line and the working chamber of which is provided with a suction-side non-return valve and a pressure-side non-return valve. The working chamber of the pulsator is connected via an oscillation line, which is filled with delivery medium, to the working chamber of the main pump head in such a way that the pulsator sucks delivery medium out of the delivery line and into the working chamber of the main pump head, or presses delivery medium out of the working chamber, in an oscillating fashion. A ventilation valve is provided for ventilating the working chamber of the pulsator, and the ventilation line is a time-controlled valve and/or a pressure-controlled double-seat valve. A device may be provided for introducing a liquid into the working chamber of the pulsator and/or the oscillation line.

Description

The invention relates to a pump device having a pulsator as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve, as claimed in the preamble of claim 1.
Within the meaning of the present disclosure of the invention, a “diaphragm pulsator” is understood in that it corresponds to a piston diaphragm pump which does not necessarily have suction-side and pressure-side non-return valves, but instead generally has all the features of a piston diaphragm pump. The person skilled in the art understands by “piston diaphragm pump” a piston pump coupled to a diaphragm, the displacement of the piston being transmitted via a hydraulic coupling to the diaphragm. In the same manner as piston diaphragm pumps, diaphragm pulsators may also comprise, in particular, a preferably position-controlled diaphragm refill device and/or ventilating device for the hydraulic fluid, as is disclosed, for example, in EP 0 085 725 A1.
In particular, the invention relates to a pump device having a pulsator, in particular a diaphragm pulsator, as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve. The working chamber of the pulsator is directly connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head such that the pulsator sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head or forces said fluid to be delivered out of the working chamber. The pump device according to the invention is particularly well-suited for delivering suspensions, such as for example mixtures of biomass and supercritical water and, in particular, for high pressures and temperatures.
Pumps of this type are disclosed in EP 0919724 B1 and EP 1898093 A1. In this connection, a main pump head located in the delivery line is driven by a further pump head which is denoted as a pulsator. Such a pump device is also denoted as a “remote head” pump. Such pump devices are typically used for pumping fluids with a high proportion of solids and at high temperatures. The known pumps may not be easily used, however, with particularly aggressive media for delivery, such as for example supercritical aqueous solutions, in particular where processes are present with a very high throughput at high temperatures and high pressures.
The object of the invention is to provide a pump device of the aforementioned type which may be used for pumping aggressive media for delivery at a high temperature and which nevertheless operates with a high degree of reliability at low cost, which is why in particular the contamination of the pulsator by solid particles should be avoided.
This object is achieved by a pump device according to the features of at least one of the independent claims. Advantageous embodiments of the invention are provided in the dependent claims.
According to an embodiment of the invention, a pump device is provided having a pulsator as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve, the working chamber of the pulsator being connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head, such that the pulsator sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head or forces said fluid to be delivered out of the working chamber, a venting valve being provided for ventilating the working chamber of the pulsator, the venting valve being a time-controlled valve and/or a pressure-controlled double-seat valve and/or a device being provided for introducing a fluid into the working chamber of the pulsator and/or the transfer line.
The use of a time-controlled valve and/or a pressure-controlled double-seat valve has the advantage that the time in which the valve is open for ventilation is able to be kept very short, whereby undesirable secondary flows may be avoided which could result in increased contamination of the pulsator by solid particles.
The introduction of fluid into the working chamber of the pulsator and/or the refilling of fluid to be delivered into the working chamber for compensating for losses, for example as a result of ventilating the working chamber, has the advantage that fluid does not have to be compensated by the driven main pump head, and thus no solid particles are transported from the main pump head to the pulsator.
According to the invention, the fluid may be water and/or fluid to be delivered and/or another suitable fluid.
According to the invention, the time-controlled and/or pressure-controlled venting valve may be a single-seat valve and/or a double-seat valve.
According to the invention, the device for introducing a fluid into the working chamber of the pulsator and/or the transfer line may comprise a time-controlled and/or pressure-controlled refill valve and/or a refill reservoir.
According to the invention, the time-controlled and/or pressure-controlled refill valve and/or venting valve may be time-controlled and/or pressure-controlled so that after a start-up phase of the process the refill valve and/or venting valve is closed and/or the upper limit value for closing the time-controlled and/or pressure-controlled refill valve and/or venting valve is increased after a start-up phase of the process and/or after a start-up phase of the process the lower limit value is reduced for closing the time-controlled and/or pressure-controlled refill valve and/or venting valve.
Preferably, the pressure to which the refill reservoir is subjected substantially corresponds to the pressure in the working chamber of the pulsator.
According to an embodiment of the invention, the refill valve may be a time-controlled and/or pressure-controlled valve between the working chamber and the refill reservoir.
According to the invention, the working chamber of the pulsator may be connected via the and/or a further venting valve to the suction side of the delivery line.
According to the invention, therefore, the suction side of the delivery line may advantageously be arranged above the venting valve for automatic ventilation.
Alternatively or additionally, according to the invention the working chamber of the pulsator may be connected via the and/or a further venting valve to the pressure side of the delivery line.
According to the invention, the venting valve may be force-controlled in combination with a return pump, in particular in a time-controlled manner.
Alternatively or additionally, according to the invention the working chamber of the pulsator may be connected via the and/or a further venting valve to a refill reservoir for compensating for leakage losses in the working chamber of the pulsator and/or the transfer line.
Alternatively or additionally, according to the invention the working chamber of the pulsator may be connected via the and/or a further venting valve to a collection container for collecting and possibly subsequently returning fluid to be delivered which is produced during the ventilation.
According to the invention, the valve may be time-controlled and/or pressure-controlled such that it is closed at least above a specific pressure.
The pulsator produces in the working chamber a continuously alternating pressure at a compression phase and a suction phase. In order to prevent a weakening of the flow from the transfer line for driving out possibly sucked-in solid particles, ventilation should not be carried out at least above a specific pressure in the working chamber in order to prevent a drop in pressure in the working chamber, even though this may be small, and thus a reduction in the flow from the transfer line.
According to the invention, the valve may be time-controlled and/or pressure-controlled such that it is closed at least below a specific pressure.
Alternatively or additionally, ventilation should be avoided below a specific pressure in the working chamber of the pulsator, as due to the drop in pressure, even though this may be small, greater suction power and thus a greater flow would be produced in the transfer line, which could suck in more solid particles into the transfer line. Thus the valve should be closed at least below a specific pressure in the working chamber.
Preferably, the ventilation only takes place in the time periods between the suction phase and the compression phase, where there is a substantially small flow or no flow at all of the fluid to be delivered into the transfer line. As a result, the flow of solid particles into the transfer line may be prevented.
According to an embodiment of the invention which may be additionally configured with the above-mentioned features of the cited embodiments of the invention, a pump device is provided with a pulsator as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve, the working chamber of the pulsator being connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head such that the pulsator sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head or forces said fluid to be delivered out of the working chamber, the pump device having a refill reservoir for refilling fluid to be delivered, which is acted upon by a pressure which substantially corresponds to the system pressure.
According to the invention, in all embodiments of the invention the transfer line may be provided with a cooling system.
According to the invention, in all embodiments of the invention the pulsator may be arranged above the main pump head. Additionally or alternatively, according to the invention the transfer line may be oriented to fall from the pulsator toward the main pump head. Such embodiments of the invention have the advantage that gravity additionally counteracts contamination by solid particles through the transfer line into the pulsator.
According to the invention, the transfer line may be provided with a sink as a receiving chamber for solid particles in the fluid to be delivered.
According to the invention, the working chamber of the pulsator may be at least occasionally acted upon by a compensating medium for compensating for leakage losses.
According to an embodiment of the invention, which may be additionally configured with the above-mentioned features of the cited embodiments of the invention, a pump device is provided with a pulsator as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve, the working chamber of the pulsator being connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head such that the pulsator sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head or forces said fluid to be delivered out of the working chamber, the transfer line in at least one portion being subdivided into at least two parallel subsections.
According to the invention, the transfer line may also be divided up over its entire path, i.e. for example two or more parallel transfer lines may be provided.
These embodiments of the invention have the advantage that by providing a corresponding control, for example, the at least two subsections are opened in the suction phase and in the compression phases at least one subsection (where there are two subsections, preferably alternately one and then the other subsection) is closed at least partially and preferably completely, at least during part of the compression phase, in order to prevent deposits of solid particles in the subsections by the resulting higher outflow velocity in the other subsection(s).
According to the invention, the volume of the subsections of the transfer line extending parallel and/or the volume of the transfer lines extending parallel may respectively be at least as great as, or preferably greater than, the swept volume of the pulsator.
This development of the invention has the advantage that an escape of solid particles into the remaining transfer line and/or the pulsator may in all likelihood be prevented.
According to the invention, control valves may be provided for at least partially opening and closing the subsections of the transfer line and/or the parallel transfer lines.
According to the invention, a sensor system may be provided in order to synchronize the timed control of the control valves with the respective phase position of the pulsator diaphragm. For example, a sensor and/or switch may be provided which operates the control valve in at least one end position of the diaphragm of the pulsator. Alternatively or additionally, a sensor and/or switch may be provided for the other diaphragm position, in order to operate the control valve. Alternatively, the control valves could also only be displaced into a closed position and/or partially closed position during one part of the compression phase. It might also be conceivable during a compression phase to close, at least partially, different control valves in succession.
According to the invention, in the region in front of the main pump head, the transfer line may preferably be subdivided into a plurality of lines arranged parallel, preferably two lines arranged parallel, which at least partially and preferably completely may be able to be at least partially closed by a time-controlled and/or pressure-controlled valve.
The time control and/or pressure control should be adjusted so that during the suction phase all lines are open as long as possible, so that the flow is distributed to the different parallel lines, whilst in the compression phases a portion of the line is alternately subjected to the full pressure and thus a substantially greater flow velocity. As a result, contamination of solid particles in the transfer line should be reliably avoided.
According to an embodiment of the invention which may be configured with the aforementioned features of the cited embodiments of the invention, a pump device is provided with a pulsator as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve, the working chamber of the pulsator being connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head such that the pulsator sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head or forces said fluid to be delivered out of the working chamber, the main pump head having at least two suction-side non-return valves arranged in parallel (16, 161).
This embodiment of the invention has the advantage that during the compression phase in the portion of the line between the outlets of the two suction-side non-return valves, a greater flow velocity is produced so that the risk of the entry of solid particles into the transfer line from the suction-side non-return valve which is downstream relative to the flow direction is reduced during the compression phase.
According to the invention, the cross section of the line receiving the suction-side non-return valve which is downstream relative to the direction of flow during the compression phase, is greater than the cross section of the line receiving the other suction-side non-return valve.
This is the preferred execution of this embodiment according to the invention, as then more solid particles are conveyed by the line, which provides increased safety relative to the contamination of solid particles in the transfer line. Alternatively, the cross sections of the two lines could also be the same size or more than two lines and a corresponding number of suction-side non-return valves could be provided. Also conceivable is a larger cross section of the suction-side non-return valve which is upstream relative to the flow direction during the compression phase, which still provides an advantage, albeit small, relative to the embodiments with only one suction-side non-return valve.
According to an embodiment of the invention which may additionally be configured with the above-mentioned features of the cited embodiments of the invention, a pump device is provided with a pulsator as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve, the working chamber of the pulsator being connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head such that the pulsator sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head or forces said fluid to be delivered out of the working chamber, a separating piston being arranged in the transfer line.
These embodiments of the invention have the advantage that the separating piston prevents solid particles thereon from passing through the transfer line from the main pump head to the pulsator.
According to the invention, the aforementioned embodiments of the pump device according to the invention may be configured with a dual-acting pulsator and two pump circuits controlled in opposing directions.
According to an embodiment of the invention, which may be additionally configured with the aforementioned features of the cited embodiments of the invention, a pump device is provided with a pulsator as a drive element for a main pump head which is located in a delivery line and the working chamber thereof is provided with a suction-side non-return valve and a pressure-side non-return valve, the working chamber of the pulsator being connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head such that the pulsator sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head or forces said fluid to be delivered out of the working chamber, the pulsator being configured as a dual-acting pulsator, one side thereof being configured as a drive element for the main pump head and the other side thereof being acted upon by a pressure which substantially corresponds to the system pressure.
Such embodiments of the invention with a dual-acting pulsator for driving two mutually controlled pump circuits are preferred as, consequently, uniform delivery may be achieved. Furthermore, the pulsator at high suction pressures of, for example, 250 bar may be driven by a drive designed for substantially lower pressures, if for example a dual-acting piston is used, which only has to overcome the pressure difference between the pressure during the compression phase in the one pulsator half and the pressure during the suction phase in the respective other pulsator half. This advantage also applies to dual-acting pulsators for driving only one pump circuit, if the other side of the pulsator which does not drive the pump circuit is acted upon by pressure. Advantageously, in embodiments of the invention with a refill reservoir for the diaphragm control chamber(s) of the pulsator, the refill reservoir is acted upon by a pressure which corresponds approximately to the system pressure, so that also during the refill process, which takes place in a valve-controlled manner, if the diaphragm reaches its rear mechanical abutment, the drive is not subjected to a greater pressure than the difference in pressure between the suction phase and compression phase, and thus does not have to be of larger size, and the diaphragm is also not destroyed on the flow channels of its rear mechanical abutment.
According to the invention, a diaphragm position-controlled refill device and/or ventilation device for hydraulic fluid may be provided in the pulsator as, for example, is disclosed in EP 0 085 725 A1.
According to the invention, for compensating for leakage losses in the diaphragm control chamber compensating medium may be present in a refill reservoir that is connected to the diaphragm control chamber via a valve, the refill reservoir being acted upon by a pressure which is greater than atmospheric pressure.
This embodiment of the invention has the advantage that the pulsator may be driven by a drive (for example hydraulically, mechanically and/or pneumatically, for example a piston drive), the power thereof only having to overcome the pressure difference between the suction side and the pressure side. Moreover, by pressure acting on the refill reservoir for compensating for leakage losses in the diaphragm control chamber, an impact on the drive, for example the piston, may be prevented. Advantageously, said pressure in the refill reservoir may correspond approximately to the system pressure. According to a further advantageous embodiment of the invention, a pressure control adapted to the system pressure by means of a control circuit may be provided in the refill reservoir, as is disclosed, for example, in EP 1 898 093 A1.
According to the invention, the pulsator may be designed to have a diaphragm or tubular diaphragm.
According to the invention, the pulsator may be designed to have a piston or plunger.
A basic idea of the invention, therefore, is also that the pulsator acts upon a main pump head, which in principle is configured as a piston pump head but without a piston being required. In this manner, a standard component which is suitable for high temperatures and pressures may be used as a pump head which, by combining with a standard diaphragm pulsator, as a whole represents a cost-effective alternative to the known solutions, the principle of a “remote head” pump being maintained. Wear is also reduced as particles possibly present in the fluid to be delivered do not come into contact with the working chamber of the pulsator, as the fluid in the transfer line is only moved to and fro within the range of the pump stroke, and is mixed only slightly with freshly suctioned fluid. The pulsator may be designed to have a diaphragm or tubular diaphragm and to have a piston or plunger. When the pulsator is a diaphragm pulsator, particles do not enter the diaphragm. As high temperatures in the fluid to be delivered are also reduced over the course of the transfer line, diaphragm pulsators with cost-effective plastics diaphragms, for example made of PTFE, may also be used at high pressures and high temperatures in the delivery line. Thus the pump devices according to the invention are particularly well suited for delivering biomass during the production of biofuel.
A further advantage is that, due to the ventilation, gases from the fluid to be delivered or air inlets may not collect in the pump chamber of the pulsator but are returned to the process. Preferably, to this end, the inlet in the suction-side delivery line is located above the venting valve so that the gases automatically escape from the working chamber. Alternatively, there may be forced ventilation, for example with a time-controlled and/or pressure-controlled valve.
In order to relieve the diaphragm pulsator still further in terms of temperature, a preferred development of the invention is that the transfer line is provided with a cooling system.
It also proves advantageous that the transfer line is orientated to fall from the diaphragm pulsator to the main pump head. The particles thus remain in the region of the main pump head and are passed back into the delivery line.
Alternatively, it may be advantageous that the transfer line is provided with a sink as a receiving chamber for solid particles in the fluid to be delivered. Thus in the transfer line a region is provided which is located below the working chamber of the diaphragm pulsator, so that the particles collect there due to gravity and do not enter the working chamber of the pulsator.
It is expedient if the working chamber of the pulsator is acted upon by a compensating medium for compensating for leakages, so that a through-flow of the transfer line and a migration of solid particles to the pulsator are prevented.
In order to protect the pulsator even further against solid particles from the fluid to be delivered, a further advantageous embodiment of the invention is to arrange a separating piston in the transfer line. As a result of this measure, the part of the transfer line associated with the pulsator is separated from the part which is associated with the main pump head.
A low driving power is achieved by a dual-acting pulsator and two pump circuits controlled in opposing directions being present, which is advantageous particularly with the use of recirculation processes at high suction pressures.

The invention is described in more detail hereinafter with reference to exemplary embodiments. In the drawings, schematically:

FIG. 1 shows a vertical section through a first embodiment of a pump device;

FIG. 1A shows a vertical section corresponding to FIG. 1 through a further pump device according to the invention, comprising a dual-acting pulsator and two pump circuits controlled in opposing directions.

FIG. 2 shows a circuit diagram of a pump configuration made up of two pump devices according to FIG. 1 according to the invention;

FIG. 3 shows features of further embodiments of a pump device according to the invention.

FIG. 4 shows a circuit diagram corresponding to FIG. 2 of an alternative pump configuration according to the invention;

FIG. 5 shows a circuit diagram corresponding to FIG. 2 of a further alternative pump configuration according to the invention;

FIG. 6 shows a circuit diagram corresponding to FIG. 2 of a further alternative pump configuration according to the invention;

FIG. 7 shows a circuit diagram corresponding to FIG. 2 of a further alternative pump configuration according to the invention;

FIG. 8 shows features of further embodiments of a pump device according to the invention.

FIG. 9 shows features of further embodiments of a pump device according to the invention.

FIG. 10 shows a circuit diagram of a pump configuration made up of two pump devices according to FIG. 1 according to the invention;

FIG. 11 shows a P-V-diagram of the time curve of the pressure of the pump over the swept volume with an indication of possible refilling during the compression phase.

FIG. 12 shows a P-V-diagram of the time curve of the pressure of the pump over the swept volume with an indication of possible refilling during the suction phase.

In the description of the exemplary embodiments, the following reference numerals are used:

- 1 Pump device
- 4 Connection (for a refill reservoir)
- 5 Pressure side (of the delivery line)
- 6 Delivery direction
- 7 Connection (for the transfer line)
- 8 Connection (for ventilation)
- 9 Venting valve
- 10 Diaphragm pulsator
- 11 Main pump head
- 12 Transfer line
- 12′ Transfer line
- 121 Subsection of the transfer line
- 122 Subsection of the transfer line (arranged in parallel with the subsection 121 of the transfer line)
- 123 Control valve (preferably a pressure-controlled or time-controlled shut-off valve)
- 124 Control valve (preferably a pressure-controlled or time-controlled shut-off valve)
- 13 Inlet
- 14 Outlet
- 15 Suction side (of the delivery line)
- 16 Suction-side non-return valve
- 161 Suction-side non-return valve (arranged in parallel with the suction-side non-return valve 16)
- 17 Pressure-side non-return valve
- 18 Working chamber (of the main pump head)
- 20 Working chamber (of the diaphragm pulsator)
- 21 Delivery fluid
- 22 Control inlet (of the main pump head)
- 23 Cooling jacket
- 24 Solid particles
- 25 Portion (in the transfer line)
- 26 Diaphragm
- 27 Diaphragm control chamber
- 28 Piston
- 281 Disk
- 29 Motor
- 30 Refill reservoir
- 31 Valve
- 32 Separating piston
- 33 Region (on side of main pump head)
- 34 Region (on side of diaphragm pulsator)
- 35 Displacement direction of separating piston
- 36 Collection container
- 37 Refill valve of diaphragm control chamber
- 38 Hydraulic pump
- 39 Venting valve of diaphragm control chamber

According to FIG. 1 a pump device 1 has a diaphragm pulsator 10 serving as a pulsator, a main pump head 11 and a transfer line 12. The main pump head 11 has an inlet 13 and an outlet 14 for installation in a delivery line, the pressure side thereof being denoted by 5 and the suction side thereof by 15. A suction-side non-return valve 16 is present on the inlet side (suction side) and a pressure-side non-return valve 17 is present on the outlet side (pressure side). The direction of delivery is identified by the arrow 6.
Structurally, the main pump head 11 corresponds namely to a pump head of a piston pump. However, it does not have a piston. Its working chamber 18 is instead directly connected to a working chamber 20 of the diaphragm pulsator 10 via the transfer line 12. The diaphragm pulsator 10 is provided with a connection 7 for the transfer line 12. Moreover, a connection 8 is present for ventilation by a venting valve 9 (FIG. 2) and a connection 4 for a refill reservoir 30 (FIG. 2). Thus the oscillating stroke of the diaphragm pulsator 10 causes the delivery in the main pump head 11 via the fluid column in the transfer line 12.
The transfer line 12 is filled with delivery fluid 21. It passes via a control inlet 22 of the main pump head 11 to the working chamber 20 of the diaphragm pulsator 10. The transfer line 12 is provided with a cooling system, which is formed by a cooling jacket 23 acted upon by coolant. In this manner, there may be a temperature reduction from, for example, approximately 360° C. at the main pump head 11, as it typically has the biomass to be delivered in biofuel production, to approximately 100° C. on the diaphragm pulsator 10.
As the transfer line 12 contains the delivery fluid 21, which may also comprise solid particles 24, a portion is present 25 in the transfer line 12 which falls from the diaphragm pulsator 10 to the main pump head 11, and which directly discharges into the working chamber 18 of the main pump head 11. At its lowest point, the transfer line 12 is thus located at the level of the working chamber 18 of the main pump head 11. The solid particles 24 remain, as a result, due to gravity in the working chamber 18 of the main pump head 11 and do not enter the working chamber 20 of the diaphragm pulsator 10. They are instead supplied to the pressure-side delivery line 5.
The diaphragm pulsator 10 has a diaphragm 26 which is hydraulically controlled via a diaphragm control chamber 27. As a diaphragm material, preferably PTFE is suitable. Alternatively, elastomers, metallic materials or composite materials may also be used. The diaphragm control chamber 27 is acted upon by a piston 28, which is driven mechanically, for example by a motor 29 (FIG. 2) and/or hydraulically and/or pneumatically, for example, by alternately subjecting the chambers adjacent to the disk 281 to pressure. For compensating for leakages, a refill reservoir 30 is present, filled with a compensation medium which, via a controlled valve 31 (FIG. 2), discharges compensation medium into the working chamber 20 of the diaphragm pulsator 10. The supply is denoted in FIG. 2 by 4.
With reference to FIG. 1 and FIG. 2, the function of the pump device is described hereinafter. The configuration shown in FIG. 2 has a dual-acting pulsator with two pump devices, as illustrated in FIG. 1. The pump devices are arranged in parallel in two branches A, B controlled in opposing directions. Initially, a pump process is described with reference to one branch. In an initial state, the piston 28 is moved into the diaphragm control chamber 27 and the diaphragm 26 bulges out into the working chamber 20 of the diaphragm pulsator 10. The transfer line 12 and the working chamber 18 of the main pump head 11 are completely filled with delivery fluid. The suction-side non-return valve 16 and the pressure-side non-return valve 17 are closed.
If the piston 28 is extended, this causes a flattening of the diaphragm 26 and a negative pressure in the working chamber 20 of the diaphragm pulsator 10. The negative pressure acts via the transfer line 12 in the working chamber 18 of the main pump head 11, so that the suction-side non-return valve 16 opens and delivery fluid 21 is sucked in from the suction side 15 of the delivery line. With the subsequent opposing stroke of the piston 28, with the bulging of the diaphragm 26, pressure is produced in the working chamber 20 of the diaphragm pulsator 10 which acts via the transfer line 12 on the working chamber 18 of the main pump head 11. The pressure causes a closing of the suction-side non-return valve 16 and an opening of the pressure-side non-return valve 17, so that delivery fluid 21 is pumped into the pressure side 5 of the delivery line. By the oscillating movement of the piston 28 a continuous delivery takes place in this manner.
By the control of two main pump heads 11 in opposing directions, by means of the dual-acting pulsator 10, which is preferably designed in the manner of a diaphragm, the pumping and suction processes with the two circuits A and B are superimposed so that, in particular, with recirculation processes at a high system pressure and a relatively small difference in pressure between the suction line and pressure line only a small amount of power is required for the drive. Alternatively, each main pump head 11 may be controlled by a single-acting pulsator in the same or opposing direction.
In FIG. 3, a portion of a transfer line 12′ is illustrated as a detail of a second exemplary embodiment. For separating the fluid column in the transfer line 12′ a separating piston 32 mounted longitudinally displaceably along the double arrow 35 is arranged in the transfer line 12′. Solid particles 24, which are possibly present, thus remain in a region 33 on the main pump head 11 side and may not enter a region 34 on the diaphragm pulsator side.
FIG. 1A shows an embodiment with a dual-acting pulsator. FIG. 1A substantially corresponds to the embodiment shown in FIG. 1, in principle the pump device of FIG. 1 being present twice, and being driven by a common piston 28. The dual-acting pulsator is shown in extremely simplified fashion in FIG. 1A, i.e. without a drive and without a hydraulic reservoir, and the refill valves are acted upon by pressure. The dual-acting piston 28 describes an end position (to the right the diaphragm 26 bulges out, i.e. the compression stroke and/or the compression phase is complete; to the left the diaphragm 26 is flattened, i.e. the suction stroke and/or the suction phase is complete).
The embodiments shown in FIGS. 2, 4, 5 and 6 of the invention substantially differ only by the different ventilation and/or refilling. The same components and features are described using the same reference numerals. Regarding the exemplary embodiments of FIGS. 4, 5 and 6, therefore, reference is made to the above description of the exemplary embodiment of FIG. 2, and hereinafter only the differences from this embodiment of the invention are described.
FIG. 2 shows an embodiment with ventilation into the suction line 15. The refilling takes place from a pressure store 30 (with a gas cushion) in a time-controlled and/or pressure-controlled manner during the compression stroke of the pulsator. The graphic symbol used for the valve 31 describes a controlled non-return valve, of which the closing is prevented when activated. The pressure in the refill reservoir 30 has to be greater than the system pressure. The refill volumetric flow has to be greater than/the same as the leakage flow of the ventilation process. A subsequent adjustment of the storage pressure is recommended depending on the changing system pressure. If required, manual control is also possible.
FIG. 4 shows an embodiment with ventilation in the pressure line 5. The refilling takes place from a pressure store 30 (with a gas cushion) in a time-controlled and pressure-controlled manner during the suction stroke of the pulsator. The graphic symbol used for the valve 31 describes a controlled non-return valve, of which the opening is prevented when activated. The pressure in the refill store 30 has to be greater than the suction pressure. The refill volume flow has to be greater than/the same as the leakage flow of the ventilation process. A subsequent adjustment of the storage pressure is recommended depending on the changing suction pressure. If required, manual control is also possible.
FIG. 5 shows an embodiment with ventilation into the refill reservoir 30. The refilling takes place from a pressure store 30 (with a gas cushion) in a time-dependent manner. The symbol for the refill valve 31 shows no specific function.
FIG. 6 shows an embodiment with ventilation into any storage or collection container 36. The refilling takes place from a pressure store 30 (with a gas cushion) in a time-dependent manner. The symbol for the refill valve 31 shows no specific function.
FIG. 7 shows an embodiment of the invention of a pump device with a single-acting pulsator. The ventilation and/or refilling may take place according to the above-mentioned embodiments of the invention, for example, according to FIG. 2, FIG. 4, FIG. 5 or FIG. 6. By way of example, the ventilation into the pressure line 5 is shown as one of the possible variants.
In the embodiment of FIG. 7, instead of the single-acting pulsator, a dual-acting pulsator could also be used, the side thereof which is not used being acted upon by a pressure which corresponds approximately to the system pressure, for example by means of a pressure store. Thus the advantages of a refill medium acted upon by pressure may be utilized for refilling into the diaphragm control chamber. Moreover, the advantage of subjecting the unused side of the dual-acting pulsator to pressure is that a drive of smaller dimensions may be used, if high pressures of, for example, 250 bar from the pump head driven by the pulsator have to be overcome.
FIG. 8 shows a possible configuration of the main pump head 11 of pump devices according to the invention. On the suction side of the main pump head two suction-side non-return valves 16, 161 are provided which may also have different sizes. This embodiment has the advantage that during the compression stroke of the pulsator a greater flow velocity is produced in the line portion between the two suction-side non-return valves.
The transfer line 12 has a gradient toward the suction-side non-return valves 161, 16. During suctioning, the suction flow corresponding to the cross-sectional ratios is divided up between the suction-side non-return valves 161 and 16. As a result, during suctioning it is achieved that in the portion of the transfer line between said two suction-side non-return valves there is a smaller flow than might be the case if the entire suctioned quantity were to be suctioned only through the suction-side non-return valve 16.
During the compression stroke, the entire quantity of fluid delivered by the pump flows through the transfer line. This has the result that fluid flows through the transfer line which, as a whole, is oriented more toward the suction-side non-return valve 16.
This flow could ensure that the deposits are instead repeatedly delivered back by the main flow.
FIG. 9 shows a possible configuration of the transfer line 12 of pump devices according to the invention. The transfer line is subdivided in at least one portion into at least 2 subsections 121, 122, which are simultaneously used for suctioning by means of controlled shut-off valves 123, 124 in the suction phases, and alternately respectively opened and closed in the compression phases in order to prevent deposits in the subsections 121, 122 of solid particles thus produced by the higher outflow velocity.
The filling volume of each of the subsections 121, 122 should preferably be at least as great as, and preferably greater than, the swept volume of the pulsator. As a result, solid particles are prevented from entering behind the controlling valves, by alternately closing in the compression phase.
In a first suction process, therefore, each subsection would initially be filled with particles to a maximum extent of up to half of its volume. The subsequently closed subsection would possibly maintain this state. With a further suction process, the subsection would then be completely filled with particles to a maximum extent, before thorough rinsing would take place in the compression phase.
In the embodiment shown in FIG. 9, time-controlled shut-off valves 123, 124 are provided which should be synchronized by means of sensor systems exactly with the respective phase position of the pulsator diaphragm.
FIG. 10 shows a further embodiment of the invention. The same parts are provided with the same reference numerals. Reference is made to the description of the above-mentioned embodiments. In FIG. 10, the pulsator is shown in slightly more detail, the drive not being shown for the dual-acting piston 28. The path of the hydraulic channels of the dual-acting pulsator is shown, in particular, in more detail.
The pump device of FIG. 10 has two refill valves 37 of the diaphragm control chamber which preferably are acted upon by a pressure which corresponds approximately to the system pressure. The pressure is provided by a hydraulic pump 38. Moreover, two venting valves 39 are provided for ventilating the diaphragm control chambers.
FIGS. 11 and 12 show schematic PV-diagrams which show the time curve of the pump pressure over the swept volume. Starting at the point on the left side below, seen very clearly here are the steep flank of the rise in pressure during the compression phase, the pressure fluctuations due to the valve kinematics, the extension of the swept volume (highest pressure at maximum piston velocity) and also the sharp decompression phase and suction phase. (Note: in the present case, in both figures for reasons of clarity the cycle has been shown clockwise).
The dotted line in FIG. 11 shows the required pressure level and a possible time window for a controlled leakage refilling process during the compression stroke. The average working pressure of the pulsator set in the compression stroke (pD) is slightly greater than the system pressure.
The dotted line in FIG. 12 shows the required pressure level and a possible time window for a controlled leakage refilling process during the suction stroke. During refilling during the suction stroke, it is sufficient if the pressure level is slightly above the suction pressure.

Claims

1. A pump device comprising a pulsator as a drive element for a main pump head which is located in a delivery line, the working chamber thereof including a suction-side non-return valve and a pressure-side non-return valve, the working chamber of the pulsator being connected, via a transfer line filled with fluid to be delivered, to the working chamber of the main pump head such that the pulsator one of sucks fluid to be delivered in an oscillating manner from the delivery line into the working chamber of the main pump head and forces said fluid to be delivered out of the working chamber, a venting valve being provided for ventilating the working chamber of the pulsator, wherein the venting valve is one of a time-controlled valve and a pressure-controlled double-seat valve, and wherein a device is provided for introducing a fluid into the working chamber of at least one of the pulsator and the transfer line.

2. The pump device as claimed in claim 1, wherein the working chamber of the pulsator is connected via a further venting valve to the suction side of the delivery line.

3. The pump device as claimed in claim 1, wherein the working chamber of the pulsator is connected via a further venting valve to the pressure side of the delivery line.

4. The pump device as claimed in claim 1, wherein the working chamber of the pulsator is connected via a further venting valve to a refill reservoir for compensating for leakage losses in the working chamber of at least one of the pulsator and the transfer line.

5. The pump device as claimed in claim 1, wherein the working chamber of the pulsator is connected via a further venting valve to a collection container for collecting and subsequently returning fluid to be delivered produced during ventilation.

6. The pump device as claimed in claim 1, wherein the pump device has a refill reservoir for refilling fluid to be delivered, which is acted upon by a pressure which substantially corresponds to the system pressure.

7. The pump device as claimed in claim 1, wherein the transfer line is provided with a cooling system.

8. The pump device as claimed in claim 1, wherein the pulsator is arranged above the main pump head.

9. The pump device as claimed in claim 1, wherein the transfer line in at least one portion is subdivided into at least two parallel subsections.

10. The pump device as claimed in claim 9, wherein the volume of the subsections of the transfer line extending parallel and/or the volume of the transfer lines extending parallel is respectively at least as great as the swept volume of the pulsator.

11. The pump device as claimed in claim 9, further comprising control valves are provided for at least partially opening and closing the subsections of the transfer line or the parallel transfer lines.

12. The pump device as claimed in claim 1, wherein the main pump head has at least two suction-side non-return valves arranged in parallel.

13. The pump device as claimed in claim 12, wherein the cross section of the line receiving the suction-side non-return valve which is downstream relative to the direction of flow during the compression phase, is greater than the cross section of the line receiving the other suction-side non-return valve.

14. The pump device as claimed in claim 1, further comprising a separating piston arranged in the transfer line.

15. The pump device as claimed in one of the preceding claim 1, wherein the pulsator is a dual-acting pulsator, the device further comprising two pump circuits controlled in opposing directions.

16. The pump device as claimed in claim 1, wherein the pulsator is configured as a dual-acting pulsator, one side thereof being configured as a drive element for the main pump head, and the other side thereof being acted upon by a pressure which substantially corresponds to the system pressure.

17. The pump device as claimed in claim 1, wherein the pulsator is designed to have a diaphragm or tubular diaphragm.

18. The pump device as claimed in claim 1, wherein the pulsator is designed to have a piston or plunger.