Abstract
The invention relates to a pumping device for pumping liquids, comprising a centrifugal pump with a radially pumping pump wheel with a hollow center. A pumping device 101 is proposed to provide a device for pumping liquids with a centrifugal pump with a radially pumping pump wheel with a hollow center, said pump being equipped to remove accumulations of gas from the interior of the pump, with a centrifugal pump 110 with a radially pumping pump wheel 201 with a hollow center, a detecting device 120 for detecting the first operating parameter 510, a sensor 130 for measuring a second operating parameter 520 and a control unit 180 for controlling the centrifugal pump 110 which is connected to the pump 110, the detecting device 120 for detecting the first operating parameter 510 and to the sensor 130, During operation, the pump 110 may be assigned a value of the first operating parameter 510 at any point in time. The control unit 180 is also equipped so that it controls the operation of the pump 110 and can remove accumulations of gas from the hollow center of the pump 110 during liquid pumping operation of the pump 110 by operating the pump 110 in a first step for removal of gas such that at least the first operating parameter 510 of the pump 110 is varied over time t, so that the first operating parameter 510 assumes a series of different predetermined values, one after another, and meanwhile values of the second operating parameter 520 associated with the values of the first operating parameter 510 are recorded, local and/or global extreme values E of the previously recorded values of the second operating parameter 520 are determined in a second step for removal of gas; those values 510E of the first operating parameter 510 are determined in a third step for gas removal, these values being associated with the extreme values E of the second operating parameter 520 previously determined; in a fourth step for removal of gas, the pump 110 is operated so that it assumes one of the values of the first operating parameter 510 associated with the extreme values E of the second operating parameter 520 for a predetermined period of time T.
Claims
1. A pumping device (101) for pumping liquids, comprising a. a centrifugal pump (110) with a radially pumping pump wheel (201) with a hollow center, wherein the pump (110) may be assigned a value of a first operating parameter (510) at any point in time during operation, b. a detecting device (120) for detecting the first operating parameter (510), c. a sensor (130) for measuring a second operating parameter (520), d. and a control unit (180) for controlling the centrifugal pump (110), which is connected to the pump (110), the detecting device (120) for detecting the first operating parameter (510) and to the sensor (130), is also equipped so that it controls operation of the pump (110) and can remove accumulations of gas from the hollow center of the pump (110) during liquid operation of the pump (110), by operating the pump (110) in a first step (310) for removal of gas so that at least the first operating parameter (510) of the pump (110) is varied over time (t) so that the first operating parameter (510) assumes a series of different predetermined values one after the other, and that meanwhile values of the second operating parameter (520) associated with the values of the first operating parameter (510) are recorded, determining local and/or global extreme values (E) of the previously recorded values of the second operating parameter (520) in a second step (320) for removal of gas, determining those values (510(E)) of the first operating parameter (510) which are associated with the previously determined extreme values (E) of the second operating parameter (520) in a third step (330) for removal of gas, operating the pump (110) in a fourth step (340) for removal of gas so that it assumes one of the values of the first operating parameter (510) associated with the extreme values (E) of the second operating parameter (520) for a predetermined period of time (T).
2. The pumping device (101) according to claim 1, equipped so that the first operating parameter (510) is a pump rotational speed per unit of time or a pump frequency of the centrifugal pump (110).
3. The pumping device (101) according to claim 1, wherein the second operating parameter (520) is structure-borne sound or sound in the liquid to be pumped, measured directly or indirectly on the pumping device.
4. The pumping device (101) according to claim 1, wherein the pump is driven electrically, and a first operating parameter (510) is an electrical operating current of the pump (110) or an operating current per rotational speed of the pump (110).
5. The pumping device (101) according to claim 4, wherein the pump (110) is an impeller pump (110) mounted to levitate magnetically and a first operating parameter (510) is a bearing current of the pump (110) or a bearing current per rotational speed of the pump (110).
6. The pumping device (101) according to any one of the preceding claims claim I, wherein the control unit (180) is equipped to carry out the fourth step (340) for a plurality of different values of the first operating parameter (510) associated with the extreme values (E) of the second operating parameter (520).
7. The pumping device (101) according to claim 1, wherein the control unit (180) is equipped to remove again any unwanted accumulations of gas after carrying out the fourth step (340) and to do so by running through the steps for removal of the accumulation of gas from the first step (310) to the fourth step (340) again, wherein the recorded values of the first operating parameter (510) of different runs may be different.
8. The pumping device (101) according to claim 1, wherein the control unit (180) is equipped to vary the first operating parameter (510) in the first step (310) in a linear fashion or on jumps at fixed intervals or as interval concatenation, approaching a predetermined value at a predetermined rate.
9. The pumping device (101) according to claim 1, wherein the control unit (180) is equipped to detect the presence of an unwanted accumulation of gas in the interior of the pump (110) by monitoring (305) the first operating parameter (510) of the pump (110) continuously or at predetermined intervals during operation of the pump (110) and comparing any changes in the operating parameter over time with predetermined detection profiles, and carrying out the removal of accumulations of gas if such an accumulation of gas is detected.
10. The pumping device (101) according to claim 1, wherein the control unit (180) is equipped to continue normal liquid pumping operation if no extreme values (E) have been discovered during the removal of accumulations of gas in the second step.
11. The pumping device (101) for transporting blood and/or medical treatment liquid and/or medical treatment waste liquid according to any one of claims 1 to 10 claim 1.
12. A medical treatment device, wherein a pumping device (101) according to claim 1 is used for transporting blood or a medical treatment liquid or a medical treatment waste liquid.
13. A method (301) for removing accumulations of gas from the interior of centrifugal pumps (110) with a radially pumping pump wheel (201) with a hollow center, with at least the following method steps: a. operating (310) a centrifugal pump, wherein a first operating parameter (510) of the pump (110) is varied so that the first operating parameter (510) assumes a series of different predetermined values one after the other, i. meanwhile at least one value of a second operating parameter (520) is recorded for each value of the first operating parameter (510), b. determining (320) local and/or global extreme values (E) of the previously recorded values of the second operating parameter (520), c. determining (330) those values of the first operating parameter (510) which are associated with the previously determined extreme values (E) of the second operating parameter (520), d. operating (340) the pump in such a way that it assumes one of the values of the first operating parameter (510) associated with the extreme values (E) of the second operating parameter (520) for a predetermined period of time.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] The device and the method are described below with reference to the drawings, in which:
[0042] FIG. 1 shows the pumping device according to the invention for pumping liquids, comprising a centrifugal pump with a radially pumping pump wheel with a hollow center, diagrammed schematically in a first embodiment,
[0043] FIG. 2 shows a pumping device according to the invention, in which, in comparison with FIG. 1, the detecting device for detecting the first operating parameter is part of the control unit or is arranged in the control unit,
[0044] FIG. 3 shows a pumping device according to the invention in which, in comparison with FIG. 1, the sensor for measuring a second operating parameter is arranged in or on a liquid line downstream from the pump and at a distance from the pump, said liquid line being connected to the pumping device and the pump,
[0045] FIG. 4 shows a pumping device according to the invention, in which, in comparison with FIG. 1, the sensor for measuring a second operating parameter is arranged at a distance from the pump, in or on a liquid line upstream from the pump, said line being connected to the pumping device and the pump,
[0046] FIG. 5 shows an example of aa pump wheel with a hollowed center for radial pumping,
[0047] FIG. 6 shows the removal of accumulations of gas according to the invention, schematically in four steps,
[0048] FIG. 7 shows a variant of the removal of accumulations of gas according to the invention, schematically, wherein a detection of accumulations of gas during regular operation and verification of the success of removal are also provided,
[0049] FIG. 8 shows a variation of the first operating parameter according to the invention and simultaneous recording of the second operating parameter as well as an extreme value in the second parameter. FIG. 8a shows a negative extreme value and FIG. 8b shows a positive extreme value.
[0050] The same or similar elements in the figures can be referenced with the same reference numerals.
[0051] FIG. 1 shows schematically a first embodiment of a pumping device 101 according to the invention. The pumping device 101 for pumping liquids has a centrifugal pump 110 with a radially pumping pump wheel with a hollow center. At least one first operating parameter 510 can be allocated to the pump 110 at any time during operation. The figure shows as one option that liquid lines 150, 155 are connected to the pumping device 101: A first line 150 carries the pump medium, i.e., the liquid to be pumped, to the centrifugal pump 110, and a second line 155 removes the liquid to be pumped from the centrifugal pump 110. The first line 150 thus runs upstream, as seen from the pump 110, while the second line 155 runs downstream, as seen from the pump 110. Other options are conceivable for connecting a pumping device proposed here to liquid lines. The connections shown here are to be regarded as one variant, but not as restrictive in any way. The pumping device also has a detecting device 120 for detecting the first operating parameter 510, In the embodiment shown here, the detecting device 120 is mounted on the pump 110 or in its vicinity, One example of such a device has a Hall sensor, for example, which is used with a pump 110, operation of which causes the occurrence of magnetic fields that are variable over time. A Hall sensor located in or on the vicinity of the pump 110 may be used to record the change in magnetic fields and thereby allow inferences about the operating condition of the pump 110. Furthermore, the device 101 has a sensor 130 for measuring a second operating parameter 520 of the device 101. In the variant shown in FIG. 1, the sensor 130 is arranged upstream of the device 101 on the device 101, in the immediate vicinity of the device 101 or near the device 101 or in the second line 155 running downstream. Furthermore, the device has a control unit 180 for controlling the centrifugal pump 110. This control unit 180 of the device 101 is connected to the pump 110, to the detecting device 120 for detecting the first operating parameter 510 of the device 101 and to the sensor 130 for measuring the second operating parameter 520 of the device 101. The control unit 180 controls the operation of the pump 110. It is conceivable for the control unit 180 to control the operation of the entire device 101, The control unit 180 is equipped, so that it can remove accumulations of gas from the hollow center of the pump 110 during operation of the device 101 or during operation of the pump 110. This is to be understood to mean that the interior of the pump 110 is initially mostly filled with the liquid to be pumped but an accumulation of gas develops in the hollow center of the pump during liquid transporting operation of the pump 110 and should now be removed. After successful removal of an accumulation of gas, there is less gas and more liquid in the interior of the pump 110. The control unit 180 is equipped to be able to remove accumulations of gas by operating the pump 110 in a first step for removal of gas and thereby varying the first operating parameter 510 of the pump 110 over time. The first operating parameter 510 may be varied in a ramp form or stepwise, for example. While the pump 110 is being operated and the first operating parameter 510 is being varied, the second operating parameter 520 is also being measured by the sensor 130. This yields values of the second operating parameter 520 as a function of the values of the first operating parameter 510, For example, the pump rotational speed per unit of time is varied as the first operating parameter 510 and structure-borne noise is thereby measured as the second operating parameter. In a second step for removal of accumulations of gas, extreme values E are sought in the previously recorded values of the second operating parameter 520. The values of the first operating parameter 510, which had applied when the extreme values E of the second operating parameter 520 were measured in a third step. In a fourth step for removal of accumulations of gas—in short: for removal of gas—the pump 110 is operated so that, for a predetermined period of time T, it assumes the operating conditions again that existed when the extreme values E of the second operating parameter 520 were measured. These conditions are characterized by the values of the first operating parameter 510 that were determined in the third step. The pump 110 thus assumes the values of the first operating parameter 510 associated with the extreme values of the second operating parameter 520 and does so for a predetermined period of time, e.g., for 5 seconds.
[0052] FIG. 2 shows schematically another embodiment of a pumping device 101 according to the invention. FIG. 2 shows the same elements as FIG. 1, but the detecting device 120 for detecting the first operating parameter 510 is indicated in immediate proximity to the control unit 180 or as an element of the control unit 180, For example, it is conceivable for the first operating parameter to be a parameter of the pump 180, which is detected by the control unit 180 during operation anyway, or which is available to the control unit 180 at least as a signal during operation. This may be the case, for example, when the first operating parameter is a pump current or a bearing current of a pump 110, for example, a magnetically levitating impeller pump 110. It may also be the case if the parameter is a pump frequency or the revolutions of a pump 110 per unit of time, for example, revolutions per minute or per second.
[0053] FIG. 3 shows schematically another embodiment of a pumping device 101 according to the invention. FIG. 3 shows a pumping device with the same elements as those shown in FIG. 1, but in contrast with the embodiment shown in FIG. 1, the sensor 130 for measuring a second operating parameter 520 here is arranged at a distance from the pump 110 (and an optional pump housing enclosing the pump 110) and is arranged at a distance from the control unit 180 in or on a liquid line leading past the pump. The sensor is thus situated downstream from the pump with respect to the direction of flow of the pumped liquid. The second operating parameter measured here might be, for example, a structure-borne noise and/or sound in the liquid.
[0054] FIG. 4 shows schematically another embodiment of a pumping device 101 according to the invention. FIG. 4 shows a pumping device with the same elements as that shown in FIG. 1, but in contrast with the embodiment shown in FIG. 1, the sensor 130 for measuring a second operating parameter 520 is arranged here at a distance from the pump 110 (and an optional pump housing, enclosing the pump 110) and arranged at a distance from the control unit 180 in or on a liquid line leading to the pump. The sensor is thus situated upstream from the pump with respect to the direction of flow of the liquid being pumped. The second operating parameter measured here might be a structure-borne noise and/or a sound in the liquid, for example.
[0055] FIG. 5 shows an example of a pump wheel 201 with a hollow center for radial pumping. A pumping device 101 for pumping liquids with a centrifugal pump 110 with a radially pumping pump wheel 201 with a hollow center might have such a pump wheel 201, for example, FIG. 5 a shows an isometric view of a pump wheel 201, and FIG. 5 b shows a partial view of a sectional drawing of the same impeller 201, Basically, the exemplary impeller 201 may be described as two essentially circular disks 210, 220 situated parallel to one another. In one variant, the circular disks 210, 220 may each have a central hole 215, 225, i.e., a hole 215, 225 at and around the midpoint, In an alternative variant, at least one of the circular disks 210, 220 is embodied as a solid circular disk, and the other circular disk 220, 210 has a central hole 225, 215. This diagram attempts to indicate both variants at the same time. In another alternative variant, which is not shown here, the impeller has only one disk 210, 220 and the blades 260 are each free on the end remote from the disk. In another alternative variant (not shown here), the impeller has two disks 210, 220, which do not have a central recess. The two disks 210, 220 are connected to the pump blades 260, which may extend as radial struts between the first disk 210 and the second disk 220, The blades 260 shown here have a radial portion based on the axis of rotation, a tangential portion and a bend, so they are not straight and do not run purely radially or purely tangentially, but instead run “diagonally,” so to speak, with a radial and a tangential portion. The hollow center of the pump 110 extends in particular in the region, which is spanned in the illustration shown here by the hole 215 in the first disk 210 and the hole 225 in the second disk 220. However, in all embodiments it is characteristic of the hollow center of the pump 110 that the pump blades 260 (also referred to as blades) do not extend into the hollow center. The hollow center of the pump 110 is thus the region on the axis of rotation of the impeller and/or immediately around it, which is free of pump blades. This region is also not filled by a solid body but instead may flow through free of the liquid to be pumped and in particular also of unwanted accumulations of gas flowing, it is conceivable for a solid body, for example, an axle or a shaft to run directly on the axis of rotation, In this case the hollow center is the region between the axle or the shaft and the pump blades which can be flown through free of the liquid to be pumped.
[0056] FIG. 6 shows a flowchart of a method 301 according to the invention for removing accumulations of gas from the interior of centrifugal pumps 110 with a radially pumping pump wheel 201 with a hollow center. This shows a sequence which can optionally be terminated after determination of extreme values if no extreme values have been detected, This optional review need not occur in all variants of the method. This method has the following method steps: [0057] operating 310 a centrifugal pump, wherein a first operating parameter 510 of the pump 110 is varied to the extent that the first operating parameter 510 assumes a series of different predetermined values one after the other; [0058] during which at least one value of a second operating parameter 520 is recorded for each value of the first operating parameter 510; [0059] determination 320 of local and/or global extreme values E of the previously recorded values of the second operating parameter 520; [0060] optionally: checking on whether extreme values E have been determined; if this check reveals that there is I at least one extreme value E, then the method is continued with the determination 330 of the respective values of the first operating parameter 510. If the check reveals that 0 there are no extreme values E, then the method is terminated 327; [0061] determination 330 of the values of the first operating parameter 510, which are allocated to the previously determined extreme values E of the second operating parameter 520; [0062] operating 340 the pump in such a way that it assumes one of the values of the first operating parameter 510 allocated to the extreme values E of the second operating parameter 520 for a predetermined period of time,
[0063] FIG. 7 shows another exemplary embodiment of a method 301 according to the invention in the form of a flowchart for removing accumulations of gas from the interior of centrifugal pumps 110 with a radially pumping pump wheel 201 with a hollow center, In contrast with the variant shown in FIG. 6, the pump 110 here is operated continuously, so that an operating parameter of the device 101 is checked 305 continuously or at predetermined intervals during regular operation. The checked parameter may be the first operating parameter 510, for example. On the basis of the values or the change in values of this operating parameter, it is detected when there are accumulations of gas in the interior of the pump 110. To this end, the values of the operating parameter can be compared with predetermined detection profiles, for example. Or exceeding or failing below a predetermined threshold value of the parameter is taken as a sign that there is an accumulation of gas in the interior of the pump 110. Alternatively or additionally, a curve for the development of the parameter, i.e., its trend, may be used to ascertain whether there is an accumulation of gas in the interior of the pump 110. If no accumulation of gas is detected when checking 305 the parameter O, then the regular operation is continued, including continuation of the check 305, If checking 305 on the parameter reveals I that there is an accumulation of gas, then steps are initiated to remove the accumulation of gas as described in conjunction with FIG. 6: varying 310 the first parameter, detecting 320 the first parameter 510 and the second parameter 520, determining 330 the extreme values E of the second parameter 520, determining values 510(E) of the first parameter 510 allocated to the extreme values E of the second parameter 520, operating the pump 110 for a predetermined period of time T wherein the pump 110 assumes a determined value 510(E) of the first parameter 510 allocated to the extreme values E of the second parameter 520. In the variant shown here, after going through these steps, there is optionally also a check on whether an accumulation of gas is still detected in the pump 110, If an accumulation of gas is still detected I in the interior of the pump 110, then the four steps 310, 320, 330, 340 are run through again, whereby the extreme values E need not assume the same values as in the previous run. A change in the extreme values E can be interpreted as a partial success in removal of gas, If an accumulation of gas is no longer detected O, then the regular operation is continued.
[0064] FIG. 8 shows as an example the variation in the first operating parameter 510 over the time tin the form of an idealized step function (shown as a solid line), in which the first operating parameter 510 assumes increasing values over the time t. FIG. 8 a shows as an example an extreme value E of an exemplary second operating parameter 520 which was recorded simultaneously and is a minimum, and FIG. 8 b shows an exemplary simultaneous curve of an exemplary second operating parameter 520, which forms an extreme value E in the form of a maximum, In both graphs, the vertical axis on the left corresponds to the size of the value of the first operating parameter 510 in arbitrary units, and the horizontal axis corresponds to the time t. The broken line curve in each case shows the change in the second operating parameter 520, while the first operating parameter 510 is varied as shown here. The right vertical axis with a broken line shows the size of the value of the second operating parameter 520. In both graphs, an extreme value E of the second operating parameter 520 occurs when the first operating parameter 510 assumes a certain value 510(E).
