DIFFERENTIAL DOSING SCALE FOR LIQUIDS, AND METHOD FOR DOSING LIQUIDS

Abstract

A differential dosing scale and method for dosing liquid. An immersion container in which the liquid to be dosed is contained and/or can be received and/or out of which the liquid to be dosed can be discharged for the dosed removal of the liquid. An immersion tube is immersed into the immersion container for the dosed removal of the liquid to be dosed from the immersion container. A dosing via which the liquid to be dosed can be suctioned out of the immersion container via the immersion tube and can be discharged from the differential dosing scale. The differential dosing scale being designed structurally and/or in terms of control technology to maintain, in the immersion container, a liquid level of the liquid to be dosed at a constant predefined and/or predefinable level relative to the immersion tube.

Claims

1. A differential dosing scale for dosing fluid, the differential dosing scale comprising: an immersion container, in which the fluid to be dosed is contained and/or is received, and/or from which the fluid to be dosed is adapted to be discharged for the dosed removal of the fluid; an immersion tube that which dips into the immersion container for the dosed removal of the fluid to be dosed from the immersion container; and a dosing pump via which the fluid to be dosed is sucked out of the immersion container via the immersion tube and discharged from the differential dosing scale, wherein the differential dosing scale is designed structurally and/or in terms of control technology such that a fluid level of the fluid to be dosed, present in the immersion container, is kept at a constant predetermined and/or predeterminable height relative to the immersion tube.

2. The differential dosing scale according to claim 1, wherein the fluid level of the fluid to be dosed, present in the immersion container, is kept at a constant predetermined and/or predeterminable height relative to an intake opening of the immersion tube.

3. The differential dosing scale according to claim 1, wherein the immersion container is displaceable along at least one path of movement, preferably running along a direction in parallel to the normal vector of the fluid level and/or to the direction of gravitational force.

4. The differential dosing scale according to claim 1, wherein the immersion tube is displaceable along at least one path of movement running along a direction in parallel to the normal vector of the fluid level and/or to the direction of gravitational force.

5. The differential dosing scale according to claim 4, wherein the dosing pump is displaceable along at least one path of movement running along a direction in parallel to the normal vector of the fluid level and/or to the direction of gravitational force, and the differential dosing scale is designed in such a way that the dosing pump is displaced in the same direction and/or at the same time as the immersion tube, and/or is kept at a constant predetermined and/or predeterminable height relative to the immersion tube and/or the fluid level.

6. The differential dosing scale according to claim 1, further comprising a detection device for detecting a position of the fluid level and/or for detecting a fill level height of the fluid in the immersion container, the detection device including an optical sensor, an ultrasonic sensor, and/or a microwave sensor.

7. The differential dosing scale according to claim 1, wherein the differential dosing scale is designed to displace the immersion container, the immersion tube, and/or the dosing pump depending on a position of the fluid level and/or a fill level height of the fluid in the immersion container, the position and/or fill level height being ascertained with the aid of the detection device.

8. The differential dosing scale according to claim 1, wherein the differential dosing scale is designed so that the immersion container and/or the immersion tube is/are displaced to maintain the constant height of the fluid level relative to the immersion tube.

9. The differential dosing scale according to claim 8, wherein the differential dosing scale is designed so that the immersion container and the immersion tube are both displaced at least temporarily simultaneously and/or in opposite directions to maintain the constant height of the fluid level relative to the immersion tube.

10. The differential dosing scale according to claim 1, wherein at least the immersion container belongs to a weighed system of the differential dosing scale.

11. The differential dosing scale according to claim 1, wherein the differential dosing scale is designed to carry out the speed and/or the direction of the displacement of the immersion container, the immersion tube, and/or the dosing pump, in each case depending on a change in the position of the fluid level and/or the fill level height of the fluid in the immersion container and/or depending on a change in the results of weighings of the weighed system.

12. The differential dosing scale according to claim 1, further comprising a storage container, in which the fluid to be dosed is contained and/or is received, the immersion container being fluidically connected to the storage container for supplying the fluid to be dosed to the immersion container from the storage container.

13. The differential dosing scale according to claim 12, wherein the storage container belongs to the weighed system of the differential dosing scale.

14. The differential dosing scale according to claim 1, wherein the differential dosing scale is designed structurally and/or in terms of control technology in such a way that a fluid level of the fluid to be dosed, present in the immersion container, is kept at a constant predetermined and/or predeterminable fill level during the operation of the differential dosing scale and/or during the dosing of the fluid.

15. The differential dosing scale according to claim 1, wherein the differential dosing scale includes a float valve arranged in a fluid connection between the storage container and the immersion container and a float body arranged in the immersion container, the float valve being controlled by the float body such that it opens the fluid connection upon dropping below the predetermined fill level and disconnects the fluid connection upon reaching the predetermined fill level.

16. The differential dosing scale according to claim 1, wherein the immersion container is arranged below the storage container in the direction of gravitational force, so that the fluid to be dosed may be supplied to the immersion container from the storage container due to the gravitational force.

17. The differential dosing scale according to claim 16, wherein the fluid connection determined via the float valve in the immersion container has a gravitational force-induced delivery rate, which is higher than a delivery rate of the dosing pump.

18. The differential dosing scale according to claim 1, wherein the volume receivable by the immersion container is adapted in that a base region and/or a wall region of the immersion container is movable and/or variable in shape, at least in regions.

19. The differential dosing scale according to claim 1, wherein the differential dosing scale is designed to adapt the volume receivable by the immersion container depending on a position of the fluid level and/or a fill level height of the fluid in the immersion container.

20. The differential dosing scale according to claim 1, wherein the differential dosing scale includes an overflow element fluidically connected to the immersion container, which is designed such that the fluid to be dosed flows out of the immersion container via the overflow element upon exceeding the predetermined fill level.

21. The differential dosing scale according to claim 20, wherein the differential dosing scale includes an overflow container, to which the overflow element is fluidically connected for collecting the fluid flowing out over the predetermined fill level, the immersion container being arranged above the overflow container in the direction of gravitational force.

22. The differential dosing scale according to claim 21, wherein the differential dosing scale includes an overflow pump, with the aid of which the fluid to be dosed is sucked out of the overflow container and supplied to the immersion container, the overflow pump having a higher delivery rate than the dosing pump.

23. The differential dosing scale according to claim 1, wherein the differential dosing scale includes a control valve arranged in a fluid connection between the storage container and the immersion container, which is controlled and/or regulated in such a way that it supplies a fluid quantity to the immersion container from the storage container, which corresponds to a fluid quantity discharged from the differential dosing scale via the immersion tube.

24. The differential dosing scale according to claim 1, wherein the immersion tube has an intake opening for sucking the fluid to be dosed out of the immersion container, which is arranged such that it dips into the fluid at an immersion depth below the predetermined fill level, which is between 1 and 10 times an immersion tube diameter.

25. The differential dosing scale according to claim 1, wherein the differential dosing scale includes a weighing device, which is designed to detect the weight of a and/or the weighed system made up, in particular, of the storage container, the immersion container, and the fluid to be dosed, contained therein, the differential dosing scale including a control and/or regulating device, which is designed to control and/or regulate the dosing pump depending on the weight of the system detected by the weighing device and depending on a control variable for a quantity of the fluid to be discharged from the differential dosing scale via the immersion tube.

26. A method for dosing fluid, wherein the fluid to be dosed is provided in an immersion container of a differential dosing scale, the method comprising: sucking the fluid to be dosed from which immersion container, for a dosed removal of the fluid, with the aid of a dosing pump via an immersion tube dipping into the immersion container for the dosed removal of the fluid to be dosed from the immersion container, and removed from the differential dosing scale; and keeping a fluid level of the fluid to be dosed in the immersion container at a constant, predetermined and/or predeterminable height relative to the immersion tube or to an intake opening of the immersion tube during an operation of the differential dosing scale and/or during the dosing of the fluid.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0099] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus, are not limitive of the present invention, and wherein:

[0100] FIG. 1 shows a schematic representation of an example of a differential dosing scale according to the invention;

[0101] FIG. 2 shows a schematic representation of an example of the differential dosing scale according to the invention;

[0102] FIG. 3 shows a schematic representation of the example of the differential dosing scale, including a regulating device;

[0103] FIG. 4 shows a schematic representation of an example of a differential dosing scale according to the invention; and

[0104] FIGS. 5 to 7 show different schematic representations of an immersion container and an immersion tube of the differential dosing scale for understanding the invention.

DETAILED DESCRIPTION

[0105] FIGS. 1 through 3 show schematic views of a differential dosing scale 1 according to the invention. Differential dosing scale 1 is used for dosing fluid 2. Differential dosing scale 1 includes a storage container 3, in which fluid 2 to be dosed is contained, and an immersion container 4, which is fluidically connected to storage container 3 for supplying fluid 2 to be dosed to immersion container 4 from storage container 3, and from which fluid 2 to be dosed may be discharged for the dosed removal of fluid 2. Differential dosing scale 1 also includes an immersion tube 5, which dips into immersion container 4 for the dosed removal of fluid 2 to be dosed from immersion container 4. Immersion tube 5 dips into immersion container 4 in such a way that no force shunt arises, and the immersion tube is not supported via immersion container 4. In particular, immersion tube 5 is arranged at a distance from a container wall of immersion container 4. Differential dosing scale 1 furthermore includes a dosing pump 6, with the aid of which fluid 2 to be dosed may be sucked out of immersion container 4 via immersion tube 5 and may be discharged from differential dosing scale 1 (for a downstream process).

[0106] According to the invention, differential dosing scale 1 is designed structurally and/or in terms of control technology in such a way that a fluid level of fluid 2 to be dosed, present in immersion container 4, is kept at a constant predetermined fill level 7 (i.e., in particular, the height of the fluid level relative to the preferably stationary immersion tube is kept constant).

[0107] In the illustrated examples, storage container 3 is connected to immersion container 4 via a connecting line/fluid line 8, and immersion tube 5 or dosing pump 6 is connected to the downstream process via a discharge line 9. Storage container 3, immersion container 4, and connecting line 8 are part of a weighed system, while immersion tube 5, dosing pump 6, and discharge line 9 are not part of the weighed system but are supported separately. In addition, a maintenance valve 10 may be arranged in connecting line 8, via which a fluid connection between storage container 3 and immersion container 4 may be blocked/disconnected for maintenance purposes.

[0108] In the example illustrated in FIG. 1, a keeping constant of predetermined fill level 7 is implemented in that a float valve 11 is arranged in connecting line 8, and a float body 12 is arranged in immersion container 4. Float valve 11 is controlled by float body 12 in such a way that it opens the fluid connection upon dropping below predetermined fill level 7 and disconnects the fluid connection upon reaching a predetermined fill level 7.

[0109] In the example illustrated in FIG. 1, immersion container 4 is arranged below storage container 3 in the direction of gravitational force, so that fluid 2 to be dosed may be supplied to immersion container 4 from storage container 3 due to the gravitational force. The gravitational force-induced delivery rate which may be implemented via float valve 11 in immersion container 4 may preferably be higher than a delivery rate of dosing pump 6 to be able to ensure sufficient refilling.

[0110] In addition, immersion container 4 may include an emptying valve 13, through whose opening fluid 2 may be discharged for completely emptying immersion container 4, and/or an overflow element 15, through which fluid 2 may flow out of immersion container 4 if an overflow fill level is exceeded.

[0111] Differential dosing scale 1 also includes a weighing device 14, which is designed to detect the weight of the weighed system, i.e., in FIG. 1, that of storage container 3, immersion container 4, connecting line 8, float valve 11, float body 12, emptying valve 13, overflow element 15, and fluid 2 contained in storage container 3, connecting line 8, and immersion container 4. The quantity of fluid 2 discharged via dosing pump 6 may 6 may preferably be gravimetrically ascertained therefrom.

[0112] In the example illustrated in FIG. 1, the keeping constant of predetermined fill level 7 is implemented in that differential dosing scale 1 includes overflow element 15 fluidically connected to immersion container 4, which is designed in such a way that fluid 2 to be dosed flows out of immersion container 4 via overflow element 15 upon exceeding predetermined fill level 7. Differential dosing scale 1 also is designed in such a way that, at any point in time, at least the same amount of fluid 2 is supplied to immersion container 4 as flows out of it via overflow element 15.

[0113] Differential dosing scale 1 may preferably also include an overflow container, which, in the example illustrated in FIG. 2, is formed by storage container 3, to which overflow element 15 is fluidically connected for collecting fluid 2 flowing out over redetermined fill level 7. Immersion container 4 may preferably be arranged above overflow container 3 in the direction of gravitational force. In particular, differential dosing scale 1 may include an overflow pump 16, with the aid of which fluid 2 to be dosed may be sucked out of overflow container 16 and supplied to immersion container 4, overflow pump 16 having a higher delivery rate than dosing pump 6. This makes it possible to ensure that, at any point in time, at least the same amount of fluid 2 may be supplied to immersion container 4 as flows out via overflow element 15.

[0114] Alternatively or additionally, differential dosing scale 1 may include a control valve, which is arranged in a fluid connection between storage container 3 and immersion container 4, and which is controlled and/or regulated in such a way that it supplies a fluid quantity to immersion container 4 from storage container 3, which corresponds to a fluid quantity discharged from differential dosing scale 1 via immersion tube 5.

[0115] FIG. 3 shows that differential dosing scale 1 includes a control and/or regulating device 17, which is designed to control and/or regulate dosing pump 6 depending on the weight of the system detected by weighing device 14 and depending on a control variable for a quantity of fluid 2 to be discharged from differential dosing scale 1 via immersion tube 5. A desired dosing quantity of fluid 2 may thus be supplied to the downstream process.

[0116] A differential dosing scale 1 in an example is illustrated in FIG. 4. The features which are identical to the features of the differential dosing scale described with reference to FIG. 1 are provided with the same reference numerals. Only the differences between differential dosing scale 1 and the differential dosing scale described with reference to FIG. 1 are therefore described below.

[0117] In the example illustrated in FIG. 4, the keeping constant of predetermined height 7 of the fluid level is implemented in that immersion container 4 is displaceable along a straight path of movement in parallel to direction of gravitational force R (which points downward in FIG. 4), which is indicated by a double arrow in FIG. 4. During the (net) discharge of fluid from immersion container 4 as a result of the dosing operation, immersion container 4 is then displaced antiparallel to direction of gravitational force R (i.e., upwardly in FIG. 4).

[0118] In this way, the fluid level dropping in immersion container 4 may be kept at a constant height relative to the immersion tube. In other words, the immersion depth of immersion tube 5 in immersion container 4 remains constant, since fluid level 7 dropping within immersion container 4 is compensated for by an equally distant, opposite upward displacement of immersion container 4.

[0119] Differential dosing scale 1 includes a detection device 17a for this purpose, with the aid of which the position of the fluid level in immersion container 4 is detected relative to a reference (for example, the intake opening of immersion tube 5). Detection device 17a is, for example, an ultrasonic sensor in the present case. It may detect the corresponding position of fluid level 7, for example, by evaluating the two-way propagation time of an emitted ultrasonic signal up to the receipt of the echo.

[0120] Differential dosing scale 1 is thus designed to displace immersion container 4 depending on a fill level height of the fluid in immersion container 4.

[0121] In this example, fluid is temporarily transferred from storage container 2 into immersion container 4. For this purpose, float valve 11 is controlled by float body 12 in such a way that it opens the fluid connection between storage container 2 and immersion container 4 upon dropping below a lower fill level limit and disconnects the fluid connection upon reaching a second fill level limit.

[0122] While the fluid is being transferred from storage container 2 into immersion container 4, immersion container 4 is displaced in parallel to direction of gravitational force R (i.e., downwardly in FIG. 4), if a net increase of the fluid quantity in immersion container 4 occurs, i.e., if more fluid is added from storage container 2 than is removed from immersion container 4 via immersion tube 5. Otherwise, for example, only the displacement speed (antiparallel to direction of gravitational force R) could be adapted, in particular reduced. This achieves the fact that the immersion depth of immersion tube 5 remains constant even during the filling of immersion container 4.

[0123] It is apparent in FIGS. 5 through 7, in an accentuated representation, that the fill level in immersion container 4 is also unable to change linearly, in particular in the case of a large removal quantity through immersion tube 5, and a slope angle ? may be formed. To prevent the formation of a slope angle ? of this type from influencing the buoyancy force of immersion tube 5, immersion tube 5 may be provided with an angled design, as illustrated in FIG. 6. As a result, an intake opening 18 of immersion tube 5 is arranged at a distance from an immersion section of immersion tube 5, so that the buoyancy force of immersion tube 5 does not change even if slope angle ? forms, since the same part of immersion tube 5 remains covered by fluid. Due to the approach according to the invention (cf. FIG. 7), however, the fill level is kept constant at predetermined fill level 7, so that a straight design of immersion tube 5 is suitable. Immersion tube 5 should have an immersion depth 19, which is as shallow as possible, however at which the impact of turbulences on the surface of fluid 2 on the suction behavior at intake opening 18 is simultaneously prevented. It has thus been shown to be advantageous if immersion depth 19 of immersion tube 5 corresponds to 1 to 10 times an immersion tube diameter 20.

[0124] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are to be included within the scope of the following claims.