AU2018363539B2

AU2018363539B2 - Pulsation damping system

Info

Publication number: AU2018363539B2
Application number: AU2018363539A
Authority: AU
Inventors: Roman Jansen
Original assignee: Mhwirth GmbH
Current assignee: Mhwirth GmbH
Priority date: 2017-11-10
Filing date: 2018-10-11
Publication date: 2024-01-18
Anticipated expiration: 2038-10-11
Also published as: CL2020001227A1; AU2018363539A1; DE102017126357A1; DE102017126357B4; PE20201320A1; EP3707376B1; EP3707376A1; WO2019091691A1

Abstract

The invention relates to a pulsation damping system (100) for reducing pressure oscillations in pipelines, in particular in the suction and/or high-pressure field of piston pumps, having a volume modification body (1) arranged in a main pipeline (10), and a volume storage container (2, 25) fluidically connected to the volume modification body (1) via at least one auxiliary pipeline (3, 3a, 3b, 3c) which is fluidically separated from the main pipeline (10). At least one throttle valve (4a, 4b) is arranged in the at least one auxiliary pipeline (3, 3a, 3b, 3c).

Description

Pulsation damping system Technical Field The invention relates to a pulsation damping system for reducing pressure oscillations in pipelines, in particular in the intake and/or high-pressure regions of piston pumps, in particular for conveying fluids with solid contents, with a volume change body arranged in a main pipeline, in particular a conveying line, and a volume storage container fluidically connected to the volume change body via at least one auxiliary pipeline fluidically separated from the main pipeline.

Background Art Such pulsation damping systems are known in numerous variants and are usually used in pipeline systems in which pressure oscillations or pressure surges can occur, for example due to the operation of a pump, an actuator or due to other flow influences. For example, during operation of piston pumps, due to the oscillating movement of the pump pistons, irregular volume flows, as inherent to the functional principle, occur both in the intake tract and at the outlet of the pump. These irregular volume flows lead to pressure pulsations, which have negative effects on the functionality of the pump and can lead to undesired vibrations in the adjacent pipeline system. In the intake tract of the pump, these pulsations can cause cavitation, which on the one hand can lead to a reduction in the efficiency of the pump and on the other hand to damage to the pump.

Known pulsation dampers usually comprise a chamber filled with a compressible gas volume and fluidically connected to the pulsating pressure chamber. These dampers act in such a way that a pressure increase is compensated by a compression of the gas volume located in the chamber. Since the gas has only a small pressure changes as a result of its high compressibility compared to the fluid, pressure pulsations due to the impressed volume flow pulsations can thus be reduced.

EP 0 679 832 Al, for example, discloses an embodiment of a damping system in which a volume change region formed by means of a compensation chamber and a flexible diaphragm arranged therein is formed in a pipeline in order to reduce

20472401_1 (GHMatters) P113646.AU pressure pulsations. A volume storage medium separated from the fluid flowing in the pipeline by means of the diaphragm is connected through an opening to a pressure compensation container for compensating a volume. Although such a design is suitable for damping relatively low pressure oscillations, it is not suitable for damping relatively high pressure surges, in particular those generated by piston pumps.

Furthermore, the use of known pulsation dampers in the case of fluids with solid contents to be conveyed is possible only to a limited extent since the throttle resistors, compensation chambers, or other pressure-damping components usually connected to a main conveying line either tend to clog due to the constrictions created or must be selected large enough to avoid clogging so that the damping effect decreases markedly.

Furthermore, the solid contents contained in the fluid are often very abrasive so that a throttle point can wear quickly when such solids flow through, which in turn negatively affects the functionality of the damper.

It may be desirable to provide a system for reducing pressure oscillations in pipelines, which system improves at least one of the aforementioned disadvantages and in particular enables effective and long-lasting use in the area of pumps for conveying fluids with solid contents, in particular so-called sludge pumps.

Summary In this regard, disclosed herein in one aspect is a pulsation damping system for reducing pressure oscillations in pipelines, in particular in the intake and/or high pressure regions of piston pumps, comprising: a volume change body arranged in a main pipeline, and a volume storage container fluidically connected to the volume change body via at least one auxiliary pipeline fluidically separated from the main pipeline. At least one throttle valve is arranged in the at least one auxiliary pipeline.

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According to the invention, at least one throttle valve is arranged in the at least one auxiliary pipeline in the pulsation damping system. This makes it possible to particularly effectively compensate and equalize particularly high pressure surges and pressure fluctuations. Furthermore, with a constant effect, clogging of a throttle resistor, a compensation chamber, or another pressure-damping component can be prevented in a particularly effective manner so that the system according to the invention is also particularly suitable for conveying systems for conveying fluids with solid contents. A substantially incompressible barrier fluid, such as a hydraulic oil, is particularly preferably arranged in the auxiliary pipeline. The barrier fluid is fluidically separated, in particular by the volume change body, from the fluid medium to be conveyed, in particular a fluid having a solid content. The barrier fluid can thus flow in the direction from the volume change body to the volume storage container, also called compensation container, and/or vice versa. Thus, for example, when a pressure surge occurs in the main pipeline, the volume change body located therein can be displaced or changed in its volume expansion in such a way that the pressure surge is transferred almost without loss from the fluid medium to the barrier fluid and, for "absorbing" the pressure surge, the barrier fluid is at least partially forced from the volume change body through the throttle located in the auxiliary pipeline into the volume storage container and expansion or enlargement of the portion or volume of the barrier fluid located therein is brought about in the volume storage container. As a result, the pressure surge can be transferred from the fluid medium to the barrier fluid in a particularly simple manner and then damped both when the barrier fluid flows through the throttle and by the displacement of the volume of the barrier fluid from the main pipeline into the volume storage container. When the throttle is flowed through, in particular a portion of the pulsation energy can be converted into heat by the pressure loss in the flow resistor. After this "absorbing" of the pressure surge and a drop in the pressure prevailing in the main pipeline to a standard pressure, which is preferably below the pressure prevailing in the auxiliary pipeline, backflow of the barrier fluid from the volume storage container in the direction of the volume change body preferably takes place so that the volume change body is expanded or displaced again into a standard position in accordance with a pressure matching. At the same time, the portion or volume of the barrier fluid located in the volume

20472401_1 (GHMatters) P113646.AU storage container decreases. Due to this design, the present pulsation damping system is particularly suitable for use in pipeline systems for conveying fluids with solid contents.

The auxiliary pipeline preferably has a first auxiliary pipeline section serving as discharge line, a separately formed second auxiliary pipeline section serving as supply line, and/or a separately formed third auxiliary pipeline section serving as supply and discharge line. In particular, a flow circuit of the barrier fluid can thereby be formed, which allows tempering, in particular cooling, of the barrier fluid heated in the at least one throttle. Thus, in particular with a relatively low volume flow or with a relatively low flow mass of the barrier fluid, a large enough circuit can thus, for example, be formed by means of the auxiliary pipeline sections so that a barrier fluid portion flowing through the throttle must first pass through a certain passage of the auxiliary pipelines and, in doing so, can again give off the heat absorbed in the throttle before "the same" barrier fluid portion flows again through the throttle and can again absorb heat in doing so. Consequently, it is possible in particular to realize the longest possible residence time of the barrier fluid in a region in which no further heating of the barrier fluid takes place. In particular, local overheating of the barrier fluid can thereby be avoided. For this purpose, for example, regulation of the flow direction of the barrier fluid is made possible; in particular, the barrier fluid can be directed selectively through previously determined auxiliary pipeline sections. For example, the barrier fluid can flow particularly quickly, i.e., in a short path, or alternatively in a particularly long path from the volume change body to the volume storage container and/or vice versa, and/or optionally flow through individual or several auxiliary pipeline sections and/or individual or several throttle valves arranged therein for damping. A throttle valve is particularly preferably respectively arranged both in the first and in the second auxiliary pipeline section. For example, in the region of the volume change body, there is both a first auxiliary pipeline section for discharging the barrier fluid from the volume change body in the direction of the volume storage container and a separate second auxiliary pipeline section for supplying the barrier fluid from the volume storage container in the direction of the volume change body, as well as a third auxiliary pipeline section, in particular an inlet and outlet

20472401_1 (GHMatters) P113646.AU of the volume storage container, which can be alternately flowed through in the direction to or from the volume storage container and which is arranged in the region of the volume storage container and connects the first and second auxiliary pipeline sections. As a result, in certain pressure situations, for example, such as in the case of rapidly successive pressure surges, partial backflow of the barrier fluid through the second auxiliary pipeline section into the volume change body can be brought about so that a subsequent pressure surge can again be effectively absorbed.

Preferably, a check valve is additionally arranged in the at least one auxiliary pipeline. The barrier fluid can thereby be directed through the auxiliary pipe sections in a targeted and predeterminable manner. In particular, backflow of the barrier fluid out of or in certain regions, such as the throttle region, can be prevented. Particularly preferably, a check valve which prevents backflow from the volume storage container in the direction of the volume change body is arranged in the first auxiliary pipeline section and a check valve which prevents backflow from the volume change body in the direction of the volume storage container is arranged in the second auxiliary pipeline section. Furthermore, overheating of the barrier fluid and/or overloading of the auxiliary pipeline system and of the volume storage container can thereby be prevented in the event of a relatively high pressure surge.

The volume change body is preferably designed as a separating device for fluidically separating a conveyed medium located in the main pipeline and a barrier fluid fluidically connected to the volume storage container and located in a barrier pressure chamber. The damping system is therefore particularly suitable for fluids to be conveyed which have solid contents. The barrier pressure chamber fluidically separated from the main pipeline particularly preferably extends from a first barrier pressure region, formed or delimited by the volume change body, through the at least one auxiliary pipeline into the volume storage container. The barrier pressure chamber preferably has a volume that is displaceable but not variable in size. This can be realized, for example, by filling the barrier pressure chamber with an incompressible barrier fluid. As a result, a pressure pulsation in the main

20472401_1 (GHMatters) P113646.AU pipeline can be transferred directly to the barrier fluid so that particularly long lasting and effective damping can take place in the auxiliary pipeline systems and the volume storage container. In particular, negative effects on the damping components by the fluid of the conveyed medium provided with solid contents can be prevented.

The volume change body preferably at least partially surrounds a chamber which is arranged inside the main pipeline and forms part of a barrier pressure chamber having the barrier fluid and whose spatial volume can be increased, reduced, or displaced by means of the volume change body as a function of a pressure present in the main pipeline. As a result, a pressure pulsation occurring in the main pipeline, in particular a pressure increase and a pressure drop, can be transferred particularly effectively to the barrier fluid arranged separated from the conveyed medium and long-lasting damping of a pulsation in a fluid provided with solid contents can consequently be made possible. For example, the spatial volume of the chamber can be reduced if a relatively high pressure is present in the main pipeline and a relatively low pressure in relation thereto is present in the auxiliary pipeline, in particular in the case of a pressure surge. Furthermore, the spatial volume of the chamber can be increased if a relatively low pressure is present in the main pipeline and a relatively high pressure is present in the auxiliary pipeline, in particular temporally after absorbing a pressure surge and returning the volume change body into an initial position. A spatial volume of a separate second chamber can be correspondingly changed when the spatial volume of the chamber is increased or reduced. For example, the spatial volume of the chamber can be displaced in that the spatial volume formed within the barrier pressure chamber by the volume change body in the region of the main pipeline is reduced or dissolved and in the region of the volume storage container is increased by means of the barrier fluid, or vice versa. This enables particularly effective damping of relatively high pressure pulsations.

In principle, the volume change body can be configured as a piston arranged and displaceably mounted between two separate fluid pressure systems, in particular the main pipeline and the auxiliary pipeline. In this way, it is also possible to

20472401_1 (GHMatters) P113646.AU transfer particularly high pressure surges to the barrier fluid in a particularly reliable manner for damping. When a pressure surge occurs, the piston can be displaced, for example, in the direction from the main pipeline to the auxiliary pipeline in order to increase the volume of the pressure system and thus to absorb the pressure surge.

The volume change body is preferably designed as a displacement body whose displacement volume is elastically variable. As a result, the pulsation damping system can also be applied in a particularly simple manner and also subsequently in the case of relatively small main pipelines or in existing installations. The displacement volume can in particular be part of the barrier pressure chamber.

Particularly preferably, the volume change body comprises a flexible and elastically deformable casing, wherein the casing surrounds a chamber fluidically connected to the at least one auxiliary pipeline, and a flow guiding device for directing the barrier fluid flowing inside the chamber is arranged in the chamber. In addition to the advantages of improved applicability mentioned above, this also achieves, for example, flowing through the entire casing and a uniform increase or decrease in the size of the volume change body that is thereby enabled so that a particularly large-area transfer to the barrier fluid and a particular quick response to a pressure surge can take place. Furthermore, the barrier fluid which flows through the chamber and which was heated, for example, in a throttle can be cooled in a particularly suitable manner by the fluid medium flowing in the main pipeline. For example, the flow guiding device can divide the chamber at least in one section into two chamber parts, in particular a discharge line part and a supply line part. The casing preferably serves for fluidic separation of the main pipeline and of the at least one auxiliary pipeline and is preferably elastically deformable in the direction to or from the chamber.

In a preferred embodiment, the volume change body is arranged upstream and/or downstream of a pump or a pump arrangement. Particularly effective, long-lasting, and cost-effective damping of pressure pulsations in a pump system can thereby take place. For example, the volume change body can be arranged upstream of a

20472401_1 (GHMatters) P113646.AU pump in an intake tract, in particular in a main pipeline, which is designed as a distributor pipe and has several main pipeline access paths to one pump in each case, in particular a piston pump. Alternatively or additionally, the volume change body can be arranged downstream of a pump, in particular in an outlet of the pump.

In addition to the barrier fluid, a gas volume is preferably additionally formed in the volume storage container. In this way, a pressure surge transferred to the barrier fluid can be damped in a particularly advantageous manner. In the event of pressure surges and a pressure difference resulting therefrom between the barrier fluid and the gas volume, a displacement of the filling level height of the barrier fluid can in particular occur with simultaneous compression of the gas volume in the volume storage container so that the pressure surge can be "cushioned" by compressing the gas volume. Furthermore, both the volume and the pressure of the barrier fluid prevailing in the at least one auxiliary pipeline can be adjusted by means of the gas pressure. The volume storage container thus acting as a hydraulic accumulator can have any desired shape; particularly preferably, the volume storage container is designed as a vertical pipe piece. In principle, for fluidic separation of the barrier fluid and the gas volume, the volume storage container can have a flexible and elastically deformable diaphragm; however, this is not absolutely necessary.

In a preferred embodiment of the invention, the main pipeline is fluidically connected upstream of the volume change body to an air vessel, wherein the conveyed medium is formed in the air vessel, preferably in a lower region of the air vessel, the so-called conveyed medium region, and a gas volume is formed in the air vessel, preferably in an upper region of the air vessel. Pressure fluctuations can thereby additionally be compensated via the air vessel so that particularly effective damping of pressure fluctuations is made possible. The air vessel can be designed, for example, as a pressure-resistant tank, advantageously with several hundred liters of capacity. The conveyed medium region of the air vessel preferably serves as a temporary reservoir for the conveyed medium to be conveyed. The gas volume under excess pressure is preferably located in the remaining region of

20472401_1 (GHMatters) P113646.AU the air vessel, the gas advantageously being air. The air vessel is particularly preferably arranged downstream of a feed pump.

The air vessel is preferably connected to the volume storage container via a connecting line. In particular, the gas volume formed in the air vessel can be fluidically connected to the gas volume formed in the volume storage container. A global pressure compensation can thereby take place in the system. Of course, further air vessels and/or volume storage containers can be connected to one another, in particular on the side of the gas volume. As a result, the control of the damping system can be made simpler and additional valves, in particular pressure valves, can be dispensed with. It remains to be noted that this arrangement can also be arranged analogously on the high-pressure side of the pump. Overall, the system is thereby designed particularly efficiently and cost-effectively.

Particularly preferably, a pressure control valve is provided for controlling or regulating the gas volume, which pressure control valve can be connected to a pressure source, for example. As a result, the damping system can be adapted in a particularly simple manner to a pressure respectively present in the main pipeline, in particular a mean or average delivery pressure. For example, the filling level height of the conveyed medium located in the air vessel and/or the filling level height of the barrier fluid located in the volume storage container can thereby be adjusted.

Heat energy is routinely supplied to the barrier fluid, in particular when it flows through the throttle. In order to avoid overheating of the barrier fluid, heat is usually dissipated via the outer walls of the volume storage container. In some applications, however, regular cooling of the barrier fluid via heat dissipation at the outer wall of the volume storage container may not be sufficient so that additional cooling of the barrier fluid is required. In an advantageous embodiment of the invention, the volume storage container therefore has a heat exchanger. The heat exchanger is used for tempering, in particular for cooling, the barrier fluid. As a result, the barrier fluid heated in the event of pressure surges, in particular in the region of the throttles, can be cooled in a particularly suitable

20472401_1 (GHMatters) P113646.AU manner, in particular effectively and in a space-saving manner. For this purpose, the heat exchanger is preferably arranged in a lower region of the volume storage container, in particular in the region in which the barrier fluid is located. The heat exchanger can be designed, for example, as an air heat exchanger with cooling ribs projecting outward.

The heat exchanger can particularly preferably be flowed through by a cooling medium and has a supply line or an inlet and a discharge line or an outlet for this purpose. As a result, the barrier fluid can be cooled particularly effectively and independently of the conveyed medium and/or an ambient temperature. The cooling medium flowing through the heat exchanger is in particular fluidically separated from the barrier fluid, the gas volume, and the conveyed medium to be conveyed. The barrier fluid can thus be actively cooled via the heat exchanger as required. The cooling medium can be water or oil, for example. Overall, the damping system is thereby also suitable in particular for a conveyed medium which has a relatively high temperature, and for use at relatively high ambient temperatures. Furthermore, it is made possible that the barrier fluid located in the barrier pressure chamber does not necessarily have to flow in a circuit so that the number of auxiliary pipelines, check valves, and/or flow guiding devices can be reduced so that the system as a whole is particularly cost-effective.

In one embodiment of the invention, a first air vessel is connected to at least one first volume storage container via a first connecting line, and a second air vessel is connected to at least one second volume storage container via a separate second connecting line. The first air vessel and the first volume storage container are preferably arranged on the pump inlet side; in particular, the main pipeline on the inlet side can be fluidically connected upstream of the volume change body to the air vessel, wherein the conveyed medium and a gas volume are formed in the air vessel. The second air vessel and the second volume storage container are preferably arranged on the pump outlet side; in particular, the outlet-side collecting pipe can be fluidically connected downstream of the volume change body to the air vessel, wherein the conveyed medium and a gas volume are formed in

20472401_1 (GHMatters) P113646.AU the air vessel. Effective pulsation damping can thereby take place both on the inlet side and on the outlet side of the pumps.

Brief Description of the Drawings Six exemplary embodiments of the invention are explained in more detail below with reference to the figures. The drawings show diagrammatic exemplifying embodiments of the present disclosure and are thus not necessarily drawn to scale. It shall be understood that the embodiments shown and described are exemplifying and that the invention is not limited to these embodiments. It shall also be noted that some details in the drawings may be exaggerated in order to better describe and illustrate the particular embodiment. They schematically show:

Figure 1 - a schematic construction of a first embodiment of a pulsation damping system according to the invention in the intake tract of a 3 piston pump;

Figure 2 - a combination of two independent pulsation damping systems on the suction and pressure sides of a piston pump;

Figure 3 - a schematic construction of a third embodiment of a pulsation damping system according to the invention;

Figure 4 - a schematic construction of a fourth embodiment of a pulsation damping system according to the invention;

Figure 5 - an embodiment with pulsation damping systems on the suction and pressure sides of a triplex piston pump;

Figure 6 - another embodiment with pulsation damping systems on the suction and pressure sides of a duplex piston pump; and

Figure 7 - a detailed view of a pulsation damping system.

Detailed Description of Selected Embodiments

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Figure 1 shows a schematic construction of a pulsation damping system 100 for damping pressure oscillations in an intake tract 10 of a pump 12a, 12b, 12c. In the present case, the pump comprises three individual pumps 12a, 12b, 12c or a 3-piston pump with three individual pump pistons which convey a fluid medium 20 and which are denoted by the reference signs 12a, 12b, 12c. Each individual pump or each pump piston 12a, 12b, 12c has a discharge line 11a, 11b, 11c which extends from a main pipeline 10, here in particular a distributor pipe, and through which the conveyed or fluid medium 20 provided, for example, with solid particles or solid contents, can be taken in, in particular from a reservoir 14 via a suction connection 13 and the distributor pipe 10.

If the individual pumps 12a, 12b, 12c each take in an intermittent volume flow from the distributor pipe 10 as is usually the case with piston pumps, irregular volume flows and the associated pressure pulsations can occur at least in the intake lines 11a, 11b, 11c, in the distributor pipe 10, and in the suction line 13. In order to damp this pressure pulsation, the pulsation damping system 100 is provided, which in particular comprises a volume change body 1, an auxiliary pipeline system 3, and a volume storage container 2. The pulsation damping system, also denoted by 101, 102, 103, or 104 below, is constructed like the system 100 described above, and in particular respectively comprises a volume change body 1, an auxiliary pipeline system 3, and a volume storage container 2 or25,25a,25b,25c,25d.

In Figure 1, the volume change body 1 is arranged in the distributor pipe 10 and is formed substantially by a flexible elastic casing or diaphragm 7. In particular, a diaphragm space or a chamber 8a is spanned or surrounded by the diaphragm 7 and a separation of the conveyed medium 20 to be pumped from another fluid 6, in particular a barrier fluid, arranged within the closed diaphragm 7 is brought about. Due to the elastic design of the diaphragm 7, the volume change body 1 is designed in particular in such a way that the volume surrounded by the diaphragm 7 can be changed in terms of magnitude, i.e., that the volume change body 1 can be alternately reduced and increased in size depending on the pressure difference prevailing at the diaphragm 7. The diaphragm 7 is in particular configured

20472401_1 (GHMatters) P113646.AU elastically in such a way that a pressure increase in the conveyed medium 20 can be transferred to the barrier fluid 6 almost without loss. For this purpose, the barrier fluid 6 is preferably a virtually incompressible fluid; ideally, a hydraulic oil is used as the barrier fluid 6.

The barrier fluid 6 located in the chamber 8a in the interior of the diaphragm 7 is connected via an auxiliary pipeline 3 to a volume storage container 2 acting as a hydraulic accumulator. Below, the volume storage container 2 is also denoted by , 25a, 25b, 25c, 25d, wherein these containers are constructed substantially identically. In the present case, all regions in which the barrier fluid 6 can flow are called barrier pressure chamber 8, wherein the barrier pressure chamber 8 in particular comprises the region of chamber 8a, a barrier pressure chamber region 8b formed in the auxiliary pipelines 3, 3a, 3b, 3c, and a barrier pressure chamber region 8c formed in the volume storage container 2. Due to the incompressibility of the barrier fluid 6, the volume of the barrier pressure chamber 8 is substantially not variable in terms of magnitude.

The volume storage container 2 is a cavity having a rigid housing wall and filled with compressed gas 15 in the upper region. In the lower region, there is a connection region 3c via which the barrier fluid 6 can pass from the diaphragm space 7 into the volume storage container 2 or, alternatively, can flow therefrom back into the reservoir. An elastic diaphragm 17 optionally arranged in the volume storage container 2 brings about a fluidic separation of the barrier pressure chamber 8, which is filled with the barrier fluid 6, from the gas volume 15. However, it should be clear that the diaphragm 17 for separating the barrier fluid 6 from the gas volume 15 is not absolutely necessary; thus, the line denoted with the reference sign 17 can also be regarded as the filling level height of the barrier fluid 6 in the volume storage container 2. The gas pressure or the gas volume 15 in the volume storage container 2 can be varied via a pressure control valve 16. In particular, the gas pressure present in the volume storage container 2 is adjusted via the pressure control valve 16 to the mean pressure of the pressure prevailing in the distributor pipe 10.

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For a particularly suitable flow ratio of the barrier fluid 6, the auxiliary pipeline 3 has several individual auxiliary pipelines or auxiliary pipeline sections 3a, 3b, 3c. As a result, the chamber 8a surrounded by the diaphragm 7 is fluidically connected to the volume storage container 2 both via an auxiliary pipeline 3a acting as a discharge line and via an auxiliary pipeline 3b arranged in parallel thereto and acting as a supply line.

In each of the auxiliary pipelines 3a and 3b, there is a throttle valve 4a and 4b, respectively, which represent a flow resistor when the barrier fluid 6 flows through and convert a portion of the flow energy into heat, thereby damping a pressure surge transferred to the barrier fluid 6. In addition to the throttles 4a, 4b, a check valve 5a, 5b is additionally provided in each of the auxiliary pipelines 3a and 3b. The blocking direction of the check valves 5a, 5b is selected such that free flow from the chamber 8a to the volume storage container 2 can take place only via the line 3a. However, backflow from the volume storage container 2 into the diaphragm space 8a can only take place via the line 3b. As a result, a defined flow direction of the barrier fluid 6 can be created, in particular in the case of rapidly successive pressure surges, and possible overheating of the barrier fluid 6 which can be generated due to heating of the barrier fluid 6 in the throttle 4a, 4b can thus be avoided. The connection of the volume storage container 2 comprises an auxiliary pipeline section 3c which is used both as a supply line and as a discharge line.

In order to generate a preferred flow direction of the barrier fluid 6 even in the chamber 8a surrounded by the diaphragm 7, a flow guiding device can be provided within the chamber 8a. In the present case, the flow guiding device 9 is in particular arranged between the connections of the auxiliary pipeline section 3a used as discharge line of the barrier fluid 6 from the chamber 8a into the volume storage container 2 and of the auxiliary pipeline section 3b used as supply line of the barrier fluid 6 from the volume storage container 2 into the chamber 8a. In particular, direct overflow of the barrier fluid 6 from the supply line 3b into the discharge line 3a can thereby be prevented. This is particularly advantageous when the barrier fluid 6 was heated, for example when flowing through the throttles 4a,

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4b, and can be cooled again in the chamber 8a by means of mixing as well as by means of heat transfer to the conveyed medium 20 present at the diaphragm 7.

When a pressure pulsation and an associated pressure increase occurs in the distributor pipe 10, a corresponding pressure increase also occurs in the barrier fluid 6 due to the elastically designed diaphragm 7 and a resulting volume reduction of the chamber 8a. Due to the check valves 5a, 5b arranged in the auxiliary pipelines 3, a volume flow of the barrier fluid 6 in the direction from the chamber 8a into the discharge line 3a through the throttle valve 4a and the check valve 5a is generated. In the throttle 4a, a portion of the flow energy of the barrier fluid 6 is converted into heat in the process. Depending on the frequency and intensity of the pressure pulsation which occurred in the distributor pipe 10 and was transferred to the barrier fluid 6, the barrier fluid 6 flowing from the throttle 4a can be conducted to a large extent via the auxiliary pipeline 3c into the volume storage container 2. In this case, the gas volume 15 can be compressed and the barrier pressure chamber region 8c can be enlarged in a manner corresponding to a pressure difference at the diaphragm 17. In addition, it is possible for a comparatively small portion of the barrier fluid 6 flowing from the throttle 4a to be additionally conducted back into the chamber 8a via the supply line 3b, the check valve 5b, and the throttle 4b. In the throttle 4b, a portion of the flow energy of the barrier fluid 6 is also converted into heat in the process. The respective flow directions or displacement possibilities of the diaphragm or of the filling level height are in each case indicated by an arrow in the figures.

If the pressure in the distributor pipe 10 now drops below the pressure adjusted in the gas volume15inthevolume storage container 2, a pressure difference opposite to the above-described case occurs at the diaphragm 7 so that a volume flow of the barrier fluid 6 from the volume storage container 2 via the supply line 3b into the interior of the chamber 8a is generated. In this case, the check valve b and the throttle 4b are again flowed through, wherein a conversion of flow energy into heat again occurs when the throttle 4b is flowed through. The two throttle points 4a and 4b arranged in the auxiliary pipeline 3 thus bring about a

20472401_1 (GHMatters) P113646.AU conversion of the pulsation energy into heat, which leads to a rapid attenuation of the pressure amplitudes in the main pipeline 10.

Since the barrier fluid 6 which flows back and forth between the chamber 8a and the volume storage container 2 is constantly heated during the conversion of the pulsation energy into heat, it is necessary to prevent the volume flow flowing into the chamber 8a from the supply line 3b from being directly sucked back into the discharge line 3a. This is because such a short-circuit volume flow could lead to an impermissible heating of the barrier fluid 6 in the auxiliary pipelines 3 if there is an ongoing pulsation excitation. Provided in the present case is therefore the flow guiding device 9, which prevents direct intake of the volume flow from the supply line 3a into the discharge line 3b and thus enables the best possible mixing of the barrier fluid 6 flowing from the supply line 3b into the chamber 8a with the residual volume. This mixing as well as the, for example relatively cold, conveyed medium located opposite the diaphragm 7 can thus prevent excessive heating of the barrier fluid 6.

Of course, the pulsation damping system 100 shown in Figure 1 and arranged on the inlet side of a pump can also be arranged on the outlet side of a pump. As a result, the pressure pulsation occurring at the outlet side of a pump can also be compensated in the manner described above. For this purpose, in particular the in the gas volume 15 of the volume storage container 2 is adapted to the mean pressure in an outlet distributor pipe.

Figure 2 shows an arrangement of two independent pulsation damping systems 100 on the suction and pressure sides of a piston pump 12a, 12b, 12c. A first pulsation damping system 101 is again arranged on the distributor pipe 10 arranged on the pump inlet side; a second pulsation damping system 102 is arranged on the collecting pipe 18 which is arranged on the pump outlet side and which substantially corresponds to the distributor pipe 10 and has a continuing line 19. The design and functionality of the pulsation damping systems 101, 102 corresponds in each case to the features of the pulsation damping system 100 explained above with reference to Figure 1.

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Figure 3 shows an embodiment of the damping system in which the suction pressure in the main distributor pipe or suction distributor 10 is applied by an upstream feed pump 24. A so-called air vessel 21 is used to decouple this feed unit, comprising the tank 14 and the feed pump 24, from the pulsations of the main pump arrangement 12. This air vessel is a large pressure-resistant tank with typically several hundred liters of capacity.

The air vessel 21 is filled in the lower region 20a as a temporary reservoir with the conveyed medium 20 to be conveyed. In the upper region, there is a gas volume a at overpressure, wherein the gas is usually air. The average filling level height of the conveyed medium to be pumped in the air vessel 21 is kept nearly constant by regulating the gas pressure 15a via the pressure control valve 22. Simulations have shown that it is sufficient for the function of the damper to supply the gas pressure 15a to the gas side of the hydraulic accumulator 2 via a connecting line 23. As a result, the damping system 100 can be designed more simply and a further pressure control valve can be dispensed with. It remains to be noted that this arrangement can also be arranged analogously on the high-pressure side of the pump since pumps can also be provided with an air vessel on the outlet side of the pump, as is illustrated with reference to the volume storage container 2 or in Figures 2, 5, and 7.

Figure 4 shows a further embodiment of the damping system 100, wherein an active cooling of the barrier fluid 6 is additionally provided. In this case, as shown in Figure 4, a heat exchanger 28 can be arranged in the volume storage container 25. A cooling medium, for example water or oil, can flow through the heat exchanger 28. For this purpose, the cooling medium can flow, independently of the conveyed medium, into the heat exchanger 28 at an inlet 26 and out of the heat exchanger 28 at an outlet 27. As a result, the heat absorbed by the barrier fluid 6 when flowing through the throttle 4 can be dissipated again via the heat exchanger 28 so that the temperature of the barrier fluid 6 can be kept substantially constant. This is particularly advantageous when heat dissipation from the barrier fluid 6 to the conveyed medium 20 or to an environment is

20472401_1 (GHMatters) P113646.AU technically not possible, for example in the case of a highly heated conveyed medium 20 or a relatively high ambient temperature. Consequently, improved applicability of the system is made possible by this embodiment. Furthermore, it is made possible that for cooling, the barrier fluid 6 located in the barrier pressure chamber 8, 8a, 8b, 8c does not necessarily have to flow in a circuit so that the number of auxiliary pipelines, check valves, and/or flow guiding devices can be reduced so that the system 100 overall is particularly cost-effective. Thus, in the example shown in Figure 4, only a single auxiliary pipeline 3c with a throttle valve 4 arranged therein is required. However, it has been shown that the arrangement of the pulsation damping system 100 shown in Figure 4 can also be operated effectively without the heat exchanger 28 arranged in the volume storage container 25, i.e., without additional cooling of the barrier fluid 6.

Figure 5 shows an exemplary embodiment of a pulsation damping system 100 on a so-called triplex piston pump. Such a pump has a total of three individual pumps 12a, 12b, 12c which are connected on the suction side to a common distributor pipe 10. The pulsation damping system 100 here comprises a combination of two pulsation damping systems 101, 102, namely a first system 101 on the suction side and a second system 102 on the pressure side of the pumps 12a, 12b, 12c. Each pulsation damping system 101, 102 again comprises in particular a volume change body 1, an auxiliary pipeline system 3, and a volume storage container a and 25b respectively.

The distributor pipe or the main pipeline 10 is connected to an inlet-side first air vessel 21a on the side of a feed pump 24 not shown. The first air vessel 21a is constructed like the air vessel 21 schematically shown in Figure 4. The inlet-side first pulsation damping system 101 with a first volume storage container 25a is arranged at an axial end of the distributor pipe 10 opposite the first air vessel 21a. The first pulsation damping system 101, in particular the first volume storage container 25a, is constructed substantially like the system 100 shown schematically in Figure 4 and shown in detail in Figure 7. In the present case, however, the first volume storage container 25a has no additional heat exchanger for cooling the barrier fluid 6. A throttle 4 is arranged in the auxiliary pipeline

20472401_1 (GHMatters) P113646.AU system 3 not shown here between the volume change body 1 not shown here and the first volume storage container 25a.

A first connecting line 23a for a fluidic connection is arranged between the first air vessel 21a, in particular a gas volume 15a arranged at the top in the first air vessel 21a, and the first volume storage container 25a, in particular a gas volume 15b arranged therein in an upper region. Separate pressure regulation of the barrier fluid 6 as well as a corresponding pressure control valve and a pressure source can thereby be dispensed with.

Arranged on the high-pressure side, i.e., at the outlet of the individual pumps 12a, 12b, 12c, is a collecting pipe 18 which, like the main pipeline 10 on the inlet side, is connected at a first axial end to a second air vessel 21b arranged on the outlet side. The second air vessel 21b is constructed substantially like the first air vessel 21a. The pipeline 19 for the further transport of the conveyed medium 20 adjoins the second air vessel 21b.

The second pulsation damping system 102 is arranged at the second axial end of the connecting pipe 18. The second pulsation damping system 102 is constructed substantially like the first pulsation damping system 101 and comprises in particular a volume change body 1 arranged in the collecting pipe 18 and not shown in the present case for better clarity, and a second volume storage container b. A throttle 4 is arranged in the auxiliary pipeline system 3, which is likewise not shown here, between the volume change body 1 and the second volume storage container 25a. Pulsations occurring on the outlet side can thereby also be effectively damped.

A second connecting line 23b for a fluidic connection is arranged between the second air vessel 21b, in particular a gas volume 15a arranged at the top in the second air vessel 21b, and the second volume storage container 25b, in particular a gas volume 15b arranged therein in an upper region. As a result, separate pressure regulation as well as a corresponding pressure control valve and a pressure source can also be dispensed with here.

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The functionality of the first pulsation damping system 101 and of the second pulsation damping system 102, in particular of the volume storage containers 25a, b, is similar to that described above, in particular with reference to the functionality described in Figures 2 and 4, wherein a connecting line 23a, 23b for compensating pressure is respectively provided here between the volume storage container 25a, 25b and the respective air vessel 21a, 21b.

Figure 6 shows a further embodiment of a pulsation damping system 100 comprising a combination of four individual pulsation damping systems, wherein two systems 101, 103 are arranged on the suction side and two systems 102, 104 are arranged on the pressure side of a duplex piston pump.

Each pulsation damping system 101, 102, 103, 104 again comprises a volume change body 1 not shown here, an auxiliary pipeline system 3 not shown here, and a volume storage container 25a, 25b, 25c, and 25d respectively. The systems 101, 102, 103, 104, in particular the volume storage containers 25a, 25b, 25c, and 25d are each constructed substantially like the system 100 shown schematically in Figure 4 and shown in detail in Figure 7, wherein the volume storage containers 25a, 25b, 25c, 25d in the present case have no additional heat exchanger for cooling the barrier fluid 6. A throttle 4 is again arranged in the auxiliary pipeline system 3 between the volume change body 1 and the first volume storage container 25a.

In the present case, the piston pump has a total of four individual pumps 12a, 12b, 12c, 12d, wherein the pumps 12a, 12b and the pumps 12c, 12d are each connected to a main pipeline 10 on the suction side. The two main pipeline sections 10 are connected to a common inlet-side air vessel 21 on the side of a purely schematically illustrated feed pump 24. The air vessel 21 is constructed like the air vessel 21 schematically shown in Figure 4. The inlet-side damping system 101 or 103 is arranged in each case at an axial end of the main pipelines 10 opposite the air vessel 21.

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The air vessel 21, in particular a gas volume 15a arranged at the top in the air vessel, can again be fluidically connected via a connecting line 23 not shown here to the volume storage container 25a and/or 25c, in particular to a gas volume 15b arranged therein in an upper region.

Provided on the outlet side of the pumps 12a, 12b, 12c, 12d is a common collecting pipe 18 which has, approximately centrally, a pipeline 19 which conducts the conveyed medium 20 to a further component, not shown, such as an outlet-side air vessel. The outlet-side damping systems 102, 104 are arranged at the two axial ends of the collecting pipe 18 in the present case. Pulsations occurring on the outlet side can thereby also be damped particularly effectively.

Figure 7 shows a detailed view of an embodiment of a pulsation damping system 100 according to the invention using the example of an application on a distributor pipe 10. Of course, this arrangement may equally also be provided on a collecting pipe 18. As already explained in detail above, in particular in reference to Figure 1, the pulsation damping system 100 comprises a volume change body 1 which is arranged here in a distributor pipe 10 with a suction connection 13 and two pump inlets 11a, 11b and is substantially formed by a flexible elastic casing or diaphragm 7. In particular, a diaphragm space 8 is spanned by the diaphragm 7 and a separation of the conveyed medium 20 to be pumped from a further barrier fluid 6 arranged within the closed diaphragm 7 is brought about. Due to the elastic design of the diaphragm 7, the volume change body 1 is designed in particular in such a way that the volume surrounded by the diaphragm 7 can be changed in terms of magnitude, i.e., that the volume change body 1 can be alternately reduced and increased in size depending on the pressure difference prevailing at the diaphragm 7. A carrier 9a having an axial end piece 9b is provided in the present case in particular for fixing the diaphragm 7. The barrier fluid 6 can form freely around the carrier 9a in the present case.

A relatively short auxiliary pipeline 3 with a throttle 4 arranged therein is arranged between the diaphragm space 8 and a volume storage container 25. Depending on the pressure ratios, the barrier fluid 6 can thus flow through the auxiliary

20472401_1 (GHMatters) P113646.AU pipeline 3 from the diaphragm space 8 into the volume storage container 25 and vice versa. Due to the pressure ratios, a filling level height 17 is formed in the volume storage container 25 and can be read from the outside via a sight glass 29. A pressure of the gas volume 15b which is formed above the filling level line 17 can be determined and output via a manometer 30.

It should be clear that the scope of the present invention is not limited to the described exemplary embodiments. In particular, the application, arrangement, and construction of the pulsation damping system can certainly be modified without changing the core of the invention. For example, the application of the pulsation damping system for damping pulsations is not limited to systems which have a pump but is suitable for any pressure chambers, such as pipelines, in which a disturbing pressure pulsation can prevail. In particular, all individual features of the respective examples can also be used in any combination.

It is to be understood that, if any prior art is referred to herein, such reference does not constitute an admission that the prior art forms a part of the common general knowledge in the art, in Australia or any other country.

In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention.

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Reference sign list:

1 Volume change body 2 Volume storage container 3 Auxiliary pipeline 3a Auxiliary pipeline section, discharge line 3b Auxiliary pipeline section, supply line 3c Auxiliary pipeline section, discharge and supply line 4 Throttle valve 4a Throttle valve 4b Throttle valve 5a Check valve 5b Check valve 6 Barrier fluid 7 Casing, diaphragm 8 Barrier pressure chamber 8a Barrier pressure chamber region, chamber 8b Barrier pressure chamber region 8c Barrier pressure chamber region 9 Flow guiding device, separating wall 9a Carrier 10 Main pipeline, distributor pipe 11 Discharge line, pump inlet 11a Discharge line, pump inlet 11b Discharge line, pump inlet 11c Discharge line, pump inlet 12 Pump 12a Pump 12b Pump 12c Pump 13 Suction connection 14 Reservoir, container 15 Gas volume

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15a Gas volume 15b Gas volume 16 Pressure control valve 17 Diaphragm, filling level height 18 Collecting pipe 19 Pipeline 20 Conveyed medium 20a Conveyed medium region 21 Air vessel 21a Air vessel 21b Air vessel 22 Pressure control valve 23 Connecting line 23a Connecting line 23b Connecting line 24 Feed pump 25 Volume storage container 25a Volume storage container 25b Volume storage container 26 Cooling medium supply line, inlet 27 Cooling medium discharge line, outlet 28 Heat exchanger 29 Sight glass 30 Manometer 100 Pulsation damping system 101 First pulsation damping system 102 Second pulsation damping system 103 Third pulsation damping system 104 Fourth pulsation damping system

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Claims

Claims:

1. A pulsation damping system for reducing pressure oscillations in pipelines, in particular in the intake and/or high-pressure regions of piston pumps, comprising - a volume change body arranged in a main pipeline, and - a volume storage container fluidically connected to the volume change body via at least one auxiliary pipeline fluidically separated from the main pipeline, wherein at least one throttle valve is arranged in the at least one auxiliary pipeline.

2. A system according to Claim 1, wherein the auxiliary pipeline has a first auxiliary pipeline section serving as discharge line, a separately formed second auxiliary pipeline section serving as supply line, and/or a separately formed third auxiliary pipeline section serving as supply and discharge line.

3. A system according to one of Claims 1 or 2, wherein a check valve is additionally arranged in the at least one auxiliary pipeline.

4. A system according to any one of the preceding claims, wherein the volume change body is designed as a separating device for fluidically separating a conveyed medium located in the main pipeline and a barrier fluid fluidically connected to the volume storage container (and located in a barrier pressure chamber.

5. A system according to any one of the preceding claims, wherein the volume change body at least partially surrounds a chamber which is arranged inside the main pipeline and forms part of a barrier pressure chamber having the barrier fluid and whose spatial volume can be increased, reduced, or displaced by means of the volume change body as a function of a pressure present in the main pipeline.

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6. A system according to any one of the preceding claims, wherein the volume change body is designed as a displacement body whose displacement volume is elastically variable.

7. A system according to any one of the preceding claims, wherein the volume change body comprises a flexible and elastically deformable casing, wherein the casing surrounds a chamber fluidically connected to the at least one auxiliary pipeline, and a flow guiding device for directing the barrier fluid flowing inside the chamber is arranged in the chamber.

8. A system according to any one of the preceding claims, wherein the volume change body is arranged upstream and/or downstream of a pump or a pump arrangement.

9. A system according to any one of the preceding claims, wherein a barrier fluid and additionally a gas volume are arranged in the volume storage container.

10. A system according to any one of the preceding claims, wherein the main pipeline is fluidically connected upstream of the volume change body to an air vessel, wherein the conveyed medium and a gas volume are formed in the air vessel.

11. A system according to Claim 10, wherein the air vessel is connected to the volume storage container via a connecting line.

12. A system according to any one of Claims 9 to 11, wherein a pressure control valve is provided for controlling or regulating the gas volume.

13. A system according to any one of the preceding claims, wherein the volume storage container comprises a heat exchanger.

14. A system according to Claim 13, wherein the system is configured to enable a separate cooling medium to flow through the heat exchanger.

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15. A system according to any one of the preceding claims, wherein a first air vessel is connected to at least one first volume storage container via a first connecting line, and a second air vessel is connected to at least one second volume storage container via a separate second connecting line.

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