Apparatus and method for supplying a liquid medium

Abstract

An apparatus for supplying a liquid medium to a metering unit comprises a housing in which media channels are arranged. One of the media channels is connected to a fluid reservoir that can be acted on by compressed air.

Claims

1. An apparatus for supplying a liquid medium to a metering unit, the apparatus comprising a housing in which a first media channel is arranged that is variable in volume, that has at least one inlet and at least one outlet, and that can have pressure applied to the first media channel by a second media channel that is variable in volume and that is arranged in the housing, with the second media channel being connected to a fluid reservoir that can be acted on by pressure and that is provided with a filling level measurement device that measures, from a change in the filling level, the volume that left the first media channel during the filling level change.

2. The apparatus in accordance with claim 1, wherein the housing is provided with a heating device.

3. The apparatus in accordance with claim 1, wherein at least one of the first media channel and the second media channel is partly areal.

4. The apparatus in accordance with claim 3, wherein at least one of the first media channel and the second media channel comprises film bags.

5. The apparatus in accordance with claim 1, wherein the second media channel is closed at one side or can be closed by means of a shut-off element.

6. The apparatus in accordance with claim 1, wherein the inlet of the first media channel is connected in one piece to a static mixer.

7. The apparatus in accordance with claim 1, wherein the fluid reservoir is provided with a floating piston that can be acted on by pressure.

8. The apparatus in accordance with claim 1, wherein the housing has a hollow space that is adapted to receive the two media channels.

9. The apparatus in accordance with claim 1, wherein the housing is configured in at least two parts and both parts are connectable to one another by a fast-closure.

10. A method for supplying a liquid medium to a metering unit, the method comprising the following steps: filling a first media channel that is variable in volume with the liquid medium; and expelling the liquid medium present in the first media channel by expanding a second media channel that is variable in volume and that is arranged next to the first media channel, wherein a repeat filling of the first media channel takes place after the expulsion of the medium, and wherein a compression of the second media channel is effected on the filling, wherein an apparatus is used to supply the liquid medium to the metering unit, the apparatus comprising a housing in which the first media channel is arranged, with a pressure being able to be applied to the first media channel by the second media channel that is variable in volume and that is arranged in the housing, with the second media channel being connected to a fluid reservoir that can be acted on by pressure and that is provided with a filling level measurement device that measures, from a change in the filling level, the volume that left the first media channel during the filling level change.

11. The method in accordance with claim 10, wherein the expansion of the second media channel takes place by a liquid that is present in the second media channel and that is acted on by pressure.

12. The method in accordance with claim 10, wherein an expulsion of the medium and a repeat filling of the first media channel take place in cycles.

13. The method in accordance with claim 10, wherein a volume increase on the expansion of the second media channel is measured and, from said volume increase, the volume of the medium expelled from the first media channel is determined.

14. The method in accordance with claim 10, wherein the medium present in the first media channel is temperature-controlled.

15. A disposable article for use in an apparatus, the apparatus comprising a housing in which a first media channel is arranged that is variable in volume, that has at least one inlet and at least one outlet, and that can have pressure applied to the first media channel by a second media channel that is variable in volume and that is arranged in the housing, with the second media channel being connected to a fluid reservoir that can be acted on by pressure and that is provided with a filling level measurement device that measures, from a change in the filling level, the volume that left the first media channel during the filling level change or in a method for supplying a liquid medium to a metering unit, the method comprising the following steps: filling a first media channel that is variable in volume with the liquid medium; and expelling the liquid medium present in the first media channel by expanding a second media channel that is variable in volume and that is arranged next to the first media channel, wherein a repeat filling of the first media channel takes place after the expulsion of the medium, and wherein a compression of the second media channel is effected on the filling, the disposable article comprising a static mixer to which a film bag is molded via a hose connection, said film bag having at least one molded on outlet.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present invention will be described in the following purely by way of example with reference to an advantageous embodiment and to the enclosed drawings. There are shown:

(2) FIG. 1 a schematic representation of an apparatus for supplying a liquid medium to a metering unit;

(3) FIG. 2 an exploded representation of a part of the apparatus of FIG. 1; and

(4) FIG. 3a a front view of the apparatus of FIG. 2 in the assembled state;

(5) FIG. 3b a side view of the apparatus of FIG. 2 in the assembled state; and

DETAILED DESCRIPTION

(6) FIG. 1 shows an apparatus for supplying a liquid medium, in the embodiment shown a two-component adhesive, to a metering unit 10. The liquid medium in this respect comprises two components A and B that are supplied from a respective tank 12 and 14 to a pump cylinder 20 and 22 via a respective check valve 16 and 18. The supply of the two components in this respect takes place at a pressure P that is sufficient to fill the two pump cylinders 20 and 22 with the respective component. The mixing ratio of the components A and B is in this respect determined by the diameter of the two pump cylinders.

(7) A drive 24 serves to expel the components A and B from the pump cylinders 20 and 22 and moves a slide 28 downwardly from the position shown in FIG. 1 via a spindle 26, whereby the two components A and B are expelled from the pump cylinders 20 and 22 into a static mixer 30 after the blocking valves 33 and 35 have been displaced by a control, not shown, from the position shown into the open position.

(8) The two components A and B are mixed with one another within the static mixer 30 and exit as a mixed medium through an outlet 32 of the static mixer into a first media channel 34 variable in volume. The first media channel 34 is arranged in a two-part housing 38 together with a second media channel 36 variable in volume.

(9) FIG. 2 illustrates that the first media channel 34 has a film bag, wherein an inlet 40 of the first media channel 34 is connected in one piece to the outlet 32 of the static mixer 30 via a hose connection 42. The inlet 40 of the first media channel 34, which is generally designed as a rectangular tubular bag, is arranged at its upper side, wherein a plurality of outlets 44 are formed at its lower side in the form of tube sections connected in one piece. Each of the tube sections 44 is connected to a metering unit 10 via a line 46 (FIG. 1).

(10) The second media channel 36 that is likewise arranged within the housing 38 generally has the same size and shape as the first media channel 34, i.e. it is likewise configured as a film bag or a tubular bag and is connected at its upper side to a metering syringe 50 via a hose connection 48, wherein a stopcock 52 is provided between the hose connection 48 and the metering syringe 50.

(11) A hose 54 is molded as an outlet to the lower side of the second media channel 36 and is connected to the lower side of a fluid reservoir 56. The fluid reservoir 56 is configured as a cylindrical cartridge, wherein a floating piston 58 is arranged in the inner space of the cartridge and is in contact-free cooperation with a filling level measurement device 60, provided outside the cartridge, to determine the respective filling level within the fluid reservoir 56.

(12) The piston 58 has compressed air applied to it at its upper side by an air cushion 62, said compressed air being regulated by an electronic pressure regulator 64 and being measured by a measurement device 66. The compressed air is provided by a pressure tank 68, for example.

(13) The fluid reservoir 56 is filled beneath the piston 58 with a supporting liquid, for example with silicone oil, that was introduced bubble-free into the second media channel 36 by the metering syringe 50. By applying compressed air to the piston 58, the fluid present within the fluid reservoir 56 and within the second media channel 36 can be acted on by pressure so that the second media channel 36 increases its volume, i.e. expands. Due to this expansion, a medium present within the first media channel 34 can be expelled in the direction of the metering unit when the two blocking valves 33 and 35 are closed.

(14) As FIG. 2 in particular illustrates, the housing 38 in the embodiment shown is formed from two half-shells 70 and 72 that are connected to one another by means of knurled screws 74 that serve as a fast-closure. The two half-shells 70 and 72 form a hollow space in the interior that is adapted to receive the two media channels 34 and 36. The hollow space has a volume that corresponds to the maximum volume of one media channel plus the minimum volume of the other media channel. Furthermore, the housing 38 is provided with a plurality of heating cartridges 76 to control the temperature of the fluids in the first and second media channels via a temperature regulation device, not shown.

(15) For a cyclical supply of a liquid medium to the metering unit 10, the medium from the two components A and B is premixed in the static mixer 30, as described above, and is subsequently introduced into the first media channel 36. In this respect, the supporting liquid present in the second media channel 36 is simultaneously displaced and expelled into the reservoir 56, whereby the filling level in the reservoir 56 changes and this filling level change is measured. When the blocking valves 33 and 35 are closed, the piston 58 is subsequently acted on by compressed air 62 so that the supporting liquid present within the second media channel 36 is acted on by pressure, whereby the medium present in the first media channel 34 can be expelled through the line 46 and the metering unit 10 when the latter is open. A complete expulsion of the medium present in the first media channel 34 can hereby take place. The volume of the first media channel 34 is subsequently minimized and the volume of the second media channel 36 is maximized. The filling level change that took place in this respect can be measured by the measurement device 60 and, from this measurement, a conclusion can be drawn in a very precise manner on the volume that was metered by the metering unit 10. In this respect, it is particularly advantageous that no components are in a direct connection with the metering medium for this measurement.

(16) It is furthermore particularly advantageous that the unit comprising the static mixer 30 and the first media channel 34 with the outlets 44 molded thereat is designed as a disposable article or a disposable article composed of plastic that can be exchanged in a simple, inexpensive and fast manner after an operating interruption.