LIQUID EJECTION DEVICE FOR A VEHICLE WASHING SYSTEM AND METHOD FOR ITS OPERATION

Abstract

A liquid ejection device for a vehicle washing system includes a reservoir volume, a first supply line coupled upstream to the reservoir for supplying a first liquid with a first supply rate and a second supply line coupled upstream to the reservoir for supplying a second liquid with a second supply rate. The device further comprises a removal line coupled downstream to the reservoir with a blocking device for blocking liquid flow through the removal line, and a detection unit for detecting liquid volume in the reservoir and a mixing ratio of the liquids introduced into the reservoir; and a removal device for ejecting the liquid found in the reservoir through an ejection element coupled to the removal line. In addition, the device comprises a control unit which is coupled to the detection unit and the removal device and is set up to start an ejection process by the removal device upon reaching a predetermined liquid volume and a predetermined mixing ratio.

Claims

1-21. (canceled)

22. A liquid ejection device for a vehicle washing system, the device comprising: a reservoir volume; a first supply line coupled upstream to the reservoir volume for supplying a first liquid with a first supply rate; a second supply line coupled upstream to the reservoir volume for supplying a second liquid with a second supply rate; a removal line coupled downstream to the reservoir volume with a blocking device for blocking a liquid flow through the removal line; a detection unit for detecting a liquid volume in the reservoir volume and a mixing ratio of the liquids introduced into the reservoir volume; a removal device for ejecting the liquid found in the reservoir volume with an ejection rate through an ejection element coupled to the removal line; and a control unit which is coupled to the detection unit and the removal device and is set up to start an ejection process by means of the removal device upon reaching a predetermined liquid volume and a predetermined mixing ratio, wherein the control unit is further coupled to a supply device for the second liquid, and wherein the supply device comprises a pressure detection element for detecting an internal gas pressure, wherein the pressure detection element is coupled to the detection unit.

23. The device according to claim 22, wherein the removal device is formed in such a way that the removal rate is greater than the sum of the maximum achievable first and second supply rate.

24. The device according to claim 22, wherein the supply device is set up to regulate the second supply rate in such a way that the predetermined mixing ratio of the first and second liquid is achieved in the reservoir volume.

25. The device according to claim 24, wherein the supply device comprises an electrical dosing pump.

26. The device according to claim 22, wherein the first liquid can be introduced with a constant volume flow.

27. The device according to claim 22, wherein the detection unit comprises a throughflow sensor for detecting the introduced volume of the first and/or second liquid.

28. The device according to claim 22, wherein the reservoir volume is sealed in a gas-tight manner, such that introducing liquid does not lead to an increase of the internal gas pressure in the reservoir volume.

29. The device according to claim 28, wherein the detection unit is set up to detect the internal gas pressure in the reservoir volume when introducing the second liquid; wherein the detection unit is set up to determine the introduced volume of the first and second liquid by means of the detected internal gas pressure in the reservoir volume.

30. The device according to claim 22, wherein the pressure detection element is set up to detect a power consumption of the supply device and to determine the internal gas pressure by means of the power consumption.

31. The device according to claim 22, wherein the removal device comprises a gas supply unit, and the control unit is set up to open the blocking device during the ejection process and to introduce an expulsion gas into the reservoir volume through the gas supply unit in such a way that the mixture is driven out of the reservoir volume with the first and second liquid.

32. The device according to claim 22, wherein the reservoir volume is formed completely from a liquid line.

33. The device according to claim 32, wherein the length of the liquid line is at least one hundred times the line diameter.

34. The device according to claim 32, wherein the liquid line is provided with a pressure bladder.

35. The device according to claim 32, wherein the geometry of the liquid line is formed in such a way that the gas found in the liquid line can flow past the dosed liquid, such that the gas accumulates in the upper part of the liquid line.

36. The device according to claim 22, wherein a branching line is arranged downstream of the blocking device for distributing the ejected liquid to at least two ejection elements.

37. A method for operating a liquid ejection device for a vehicle washing system, the method comprising: supplying a first liquid to a reservoir volume with a first supply rate and a second liquid with a second supply rate; blocking a liquid flow out of the reservoir volume by means of a blocking device coupled downstream to the reservoir volume; and detecting a liquid volume in the reservoir volume and a mixing ratio of the liquids introduced into the reservoir volume by means of a detection unit, wherein the blocking device is opened by means of a control unit, which is coupled to the detection unit, upon reaching a predetermined total volume and a predetermined mixing ratio, and an ejection process is started with a removal rate, wherein the control unit is further coupled to a supply device for the second liquid, wherein an internal gas pressure is detected by means of a pressure detection element of the supply device, wherein the pressure detection element is coupled to the detection unit.

38. The method according to claim 37, wherein the ejection rate is higher than the maximum supply rate.

39. The method according to claim 37, wherein the ejection of the liquid is carried out by means of an expulsion gas supplied with pressure.

40. The method according to claim 37, wherein the liquid ejected from the reservoir volume is distributed to at least two ejection elements through a branching line arranged downstream of the blocking device.

41. The method according to claim 37, wherein the first liquid is supplied with a substantially constant first supply rate.

Description

[0061] The invention is now explained by means of exemplary embodiments with reference to the drawings.

[0062] FIGS. 1 and 2 show a first exemplary embodiment of the liquid ejection device according to the invention, and

[0063] FIG. 3 shows a further exemplary embodiment of the liquid ejection device according to the invention.

[0064] An exemplary embodiment of the device according to the invention is explained with reference to FIGS. 1 and 2. Here, FIG. 2 shows a more detailed view than FIG. 1.

[0065] The device comprises a feed line 10, 210, which is attached to a supply opening 11, 211 of a storage container 4, 204. The storage container 4, 204 further comprises a removal opening 12, 212 to which a removal line is attached to form a T-piece 5, 205, wherein, in the removal line, a blocking device 15, 215, formed as a blocking valve 15, 215 and, in particular, as a pinch valve, is arranged. The line is branched into two distributor lines 6, 7, 206, 207 by the T piece 5, 205, said distributor lines leading to nozzles 8, 9 of a vehicle washing system. A different branching line can also be used instead of the T-piece 5, 205. In the exemplary embodiment, the storage container 4, 204 is sealed in a gas-tight manner when the blocking device 15, 215 is closed. In this case, an exchange of fluids can be carried out by the supply opening 11, 211, wherein the feed line 10, 210 attached to this can, however, be sealed in a gas-tight manner by closing the attached valves.

[0066] A chemical supply 2, 202 with a check valve 2a, 202a and an air supply 3, 203 with a further check valve 3a, 203a are attached to the feed line 10, 210. Here, the chemical supply 2, 202 is connected to a supply unit 222, in particular an electrical dosing pump 222, by means of which a liquid, in particular a detergent, can be supplied. The electrical dosing pump 222 comprises a pressure detection element 222a. Moreover, the air supply 3, 203 is connected to a gas supply unit 223, in particular an air compressor or a different source of pressurised air. Downstream of this, a further check valve 1a, 201a, an electromagnetic water valve 201c, a throttle 1b, 201b and a water supply 1, 201 attached to a water supply device are provided in the feed line 10, 210. In the exemplary embodiment, the storage container 4, 204 and a feed line 10, 210 thus form a reservoir volume which can receive a certain fluid volume.

[0067] A control unit 230 is provided to control the device, said control unit comprising a detection unit 231 and being coupled to the electromagnetic water valve 201c, the electrical dosing pump 222, the gas supply line unit 223 and the blocking valve 15, 215.

[0068] Water is fed from the water supply 1, 201 into the feed line 10, 210 with a constant pressure, wherein the water volume flow can be set by means of the throttle 1b, 201b. Furthermore, the water supply can be switched on and off by means of the electromagnetic water valve 201c. The supplied water passes the check valve 1, 201a. The further check valve 3a, 203a prevents the water penetrating in the direction of the air supply 3, 203. The water flow further passes the coupling to the chemical supply 2, 202, wherein, here, a check valve 2a, 202a also prevents the water penetrating. Finally, it reaches the storage container 4, 204 through the supply opening 11, 211.

[0069] In further exemplary embodiments, at least one throughflow sensor can be provided which can be arranged in the feed line 10, 210, for example. Furthermore, it can be arranged in the region of the water supply 1, 201 and/or the chemical supply 2, 202.

[0070] An exemplary embodiment of the method according to the invention is explained with reference to FIGS. 1 and 2.

[0071] In the exemplary embodiment of the method, in a base state, the blocking valve 15, 215 is closed, such that the storage container 4, 204 is sealed in a gas-tight manner up to the supply opening 11, 211. The storage container 4, 204 and, in particular, also the feed line 10, 210 are filled with air in the base state. Thus, it leads to an increase of the air pressure in the empty storage container 4, 204 when introducing liquid into the storage container 4, 204. The introduced liquid cannot be compressed, such that the liquid volume introduced into the storage container 4, 204 can be determined by means of the internal gas pressure. This is carried out by means of the Boyle-Mariotte law, which describes the relation between pressure and volume of an ideal gas under isothermal conditions. For the purposes of the invention, the description as an ideal gas is sufficient, yet modifications and corrections for adjusting the calculation process to the real circumstances can also be provided.

[0072] In the base state, the volume V.sub.1 of the empty storage container 4, 204 corresponds to the volume V.sub.1 of the gas found inside it. In the first state, this has the pressure p.sub.1 which corresponds, in particular, to the ambient pressure. After introducing a volume V.sub.3 of liquid, the gas found in the storage container 4, 204 assumes a reduced volume V.sub.2, which is calculated according to the difference V.sub.2=V.sub.1−V.sub.3. Since the liquid volume V.sub.3 cannot be compressed, the pressure p.sub.2 of the gas increases as a result of the reduced volume according to the equation:

p.sub.1*V.sub.1=p.sub.2*V.sub.2

[0073] From this, the following emerges for calculating the liquid volume V.sub.3 introduced:

V.sub.3=V.sub.1*(1−p.sub.1/p.sub.2)

[0074] Alternatively or additionally, other estimations can be used to calculate the liquid volume introduced by means of the internal gas pressure p.sub.1, p.sub.2.

[0075] In the exemplary embodiment, the internal gas pressure p.sub.1, p.sub.2 is detected by the pressure detection element 222a, which detects the power consumption of an electrical dosing pump 222, by means of which the second liquid is supplied to the chemical supply 2, 202. In the exemplary embodiment, a detergent is pumped by the chemical supply 2, 202 and through the check valve 2a, 202a into the field line 10, 210. Here, the pump 222 works against the internal gas pressure in the storage container 4, 204, such that a higher power of the dosing pump 222 is necessary with increasing internal gas pressure to reach the same introduction rate of the detergent.

[0076] In the exemplary embodiment, a magnet-membrane dosing pump of the type gamma/X by the company ProMinent® is used as the dosing pump 222. This pump has a magnetic regulator which measures and releases the upcoming counterpressure. During operation, e.g. a target value of 27 ml/min is input for the volume flow. The regulator of the pump then displays the counterpressure. This counterpressure still contains the pressure of the liquid when feeding the liquid and frictional losses in the line. However, these pressures are constant, such that the internal gas pressure in the storage container 4, 204 or generally in a reservoir volume emerges from the pressure differences.

[0077] This means that liquid volume found in the storage container 4, 204 is determined by means of the internal gas pressure. This is advantageous, in particular, when there are no or only inexact possibilities for directly measuring the volume available, for example with a throughflow measuring at the water supply 1, 201 or in the feed line 10, 210.

[0078] At the same time, it is provided in the exemplary embodiment that the electrical dosing pump 222 measures the volume of the detergent pumped by it when feeding in the detergent. In other exemplary embodiments, a throughflow sensor can be used for this.

[0079] Additionally or alternatively, in further exemplary embodiments, a different sensor can be provided for measuring the liquid volume in the storage container 4, 204. For example, a float can be used or the mass of the liquid introduced can be determined.

[0080] In the storage container 4, 204, the water is mixed with the detergent, which is indicated in FIGS. 1 and 2 by a round arrow. Here, the first and second liquid can be distributed homogenously in the liquid mixture. Additionally, in the exemplary embodiment, the injection of the mixture is carried out in such a way that an extensively homogenous mixture is achieved, in particular when applying to a surface, i.e. shortly after leaving the system. In a further exemplary embodiment, the mixing can be improved by an additional mixing device (not depicted).

[0081] A current mixing ratio between the water and the detergent emerges from the volume of the detergent fed in and the total liquid volume in the storage container 4, 204. The mixing ratio can also be adjusted by controlling the water supply 1, 201, for example by means of the throttle 1b, 201b and the electromagnetic water valve 201c, and/or the chemical supply 2, 202 by means of the dosing pump 222.

[0082] At the same time, in the exemplary embodiment, the liquid volume in the storage container 4, 204 is compared to a predetermined target volume. When the target volume is reached, which corresponds in particular to reaching a predetermined target pressure in the storage container 4, 204, the introduction of water and detergent is ended, in the exemplary embodiment by closing the electromagnetic water valve 201c and stopping the electrical dosing pump on the chemical supply 2, 202.

[0083] It is provided in the exemplary embodiment that the mixture is ejected from the storage container 4, 204 by means of pressurised air after reaching the target volume. For this, pressurised air is introduced at the air supply 203. The air supply 203 thus assumes the role of a removal device 223; alternatively or additionally, in other exemplary embodiments, another removal device 223 can be provided, for example a pump for ejecting the liquid from the storage container 4, 204. A pressure of 4 to 8 bar, preferably 6 bar, is provided. The check valve 201a prevents the pressure being diverted in opposition to the flow direction in the feed line 10, 210, and the air supplied with pressure reaches the storage container 4, 204. At the same time, the blocking valve 15, 215 is opened. Since the removal opening 12, 212 is arranged in the lower region of the storage container 4, 204, the amount of liquid found therein can be substantially completely ejected.

[0084] In further exemplary embodiments, it can be provided that the blocking valve 15, 215 is formed as an overpressure valve and automatically opens upon reaching a certain pressure, for example at a pressure of 6 bar. In addition, further valves can be provided, for example in the distributor lines 6, 7, 206, 207.

[0085] The liquid mixture ejected from the storage container 4, 204 is led into the distributor lines 6, 7, 206, 207 by the T-piece 5, 205 and there reaches the ejection elements 8, 9 which are not depicted in more detail in FIG. 1. In the exemplary embodiment, it is nozzles 8, 9 of a vehicle washing system.

[0086] In the exemplary embodiment, pressurised air is led into the storage container 4, 204 until it is completely emptied. Here, it is further provided that the attaching lines, in particular the T-piece 5, 205, and the distributor lines 6, 7, 206, 207 and, where necessary, the nozzles 8, 9 are also emptied and the liquid mixture is ejected completely through the nozzles 8, 9. In this way, possibly aggressive chemicals lingering unnecessarily long in the components of the system and dripping are prevented.

[0087] In a final step, the supply of the pressurised air is ended and the blocking valve 15, 215 is closed. Here, the storage container 4, 204 is filled with air at ambient pressure.

[0088] In further exemplary embodiments, the ejection can be carried out in a different manner, for example by introducing water or a different fluid under pressure or by suctioning out of the storage container 4, 204 by means of a pump and ejecting through the distributor line 6, 7, 206, 207.

[0089] With reference to FIG. 3, a further exemplary embodiment of the device according to the invention is explained. The present construction is fundamentally analogous to that shown in FIGS. 1 and 2. Thus, above all the differences are explained below.

[0090] In the further exemplary embodiment, it is provided that the storage container is formed by a feed line 110. Here, the feed line 110 is formed in such a way that it comprises a sufficiently large volume for the provision of the desired mixture.

[0091] For example, a 4 m long feed line 110 is provided which, with an internal diameter of 4 mm, contains a volume of about 50 ml and, with an internal diameter of 6 mm, a volume of about 113 ml of liquid. The feed line 110 leads to a T-piece 105 which can be formed in a different manner, for example in order to enable a rotation around the axis of the feed line 110. Distributor lines 106, 107 branch off from this T-piece 105 downstream, the length of which being 5 m in total, for example, which corresponds to a volume of about 63 ml with an inner diameter of 4 mm. Nozzles 108, 109 are provided at the end of the distributor lines 106, 107, by means of which nozzles a liquid can be sprayed out, for example onto rims of a vehicle in a vehicle washing system. The feed line 110 and the distributor lines 106, 107 thus form a reservoir volume into which fluid can be introduced.

[0092] Upstream at the other end of the feed line 110, a water supply 101 is attached to a throttle 101b and a check valve 101a, a chemical supply 102 to a check valve 102a, and an air supply 103 to a check valve 103a.

[0093] In the exemplary embodiment shown here, it is provided that a constant flow of water is led into the feed line 110 through the throttle 101b. Furthermore, it is provided that a detergent is injected at the chemical supply 102, wherein an electrical dosing pump is used. In each case, a valve 106a, 107a that is gas and liquid-tight is provided in the distributor lines 106, 107, said valve being able to be respectively opened by an electrical signal at a certain pressure, for example 5 bar. In each case, a pressure bladder 116, 117 is arranged in front of each valve 106a, 107a in the distributor line 106, 107. As with the storage container 4, 204, gas is compressed in the pressure bladders 160, 117. Thus, when introducing water and detergent, a pressure is constructed in the feed line 110 and the distributor lines 106, 107. During the introduction of the detergent, this pressure is measured at the chemical supply 102 by means of the power consumption of the electrical dosing pump. As described above, in this way, the total volume of the current introduced liquid can be determined. At the same time, the electronic dosing pump measures the injected volume of the detergent and controls the supply line in such a way that a predetermined mixing ratio is achieved.

[0094] Upon reaching the predetermined mixing ratio and a predetermined volume, the mixture found in the feed line 110 and the distributor lines 106, 107 is ejected by pressurised air being supplied with a high pressure, for example 6 bar, in the air supply 103. The valves 106a, 107a are opened, for example by means of electrical signals, and the mixture can be sprayed out through the nozzles 108, 109.

[0095] Furthermore, it is provided in the exemplary embodiment that a flow of water is emitted through the nozzles 108, 109 after emitting the mixture, wherein the feed line 110, the T-piece 105 and the distributor lines 106, 107 as well as the nozzles 108, 109 are cleaned. In addition, running on can be avoided by the nozzles 108, 109 being supplied with pressurised air on the end in order to eject the remaining liquid.

[0096] Mixing the liquids introduced can occur in the device by these being simultaneously introduced. However, a homogenous mixing does not necessarily have to be achieved, but rather the components of the mixture being homogenously mixed by the application with high-pressure outside the device can suffice.

[0097] In a further exemplary embodiment, the liquids are provided by the same supply unit, in particular one after the other. For example, a pump can be provided which firstly introduces water and then a detergent into the storage container 4, 204.

[0098] In yet another exemplary embodiment, the pressurised bladder 116, 117 in the device according to FIG. 3 is dispensed with. In this case, the gas found in the feed line 110 and the distributor lines 106, 107 is superseded by the supplied liquid, such that the gas accumulates in the upper part of the feed line 110 and is compressed there. The air supply 103 is also in this upper region, via which air supply pressurised air can be supplied with high pressure.

[0099] Thus, in this case, firstly the blocking devices 106a, 107a are closed and the liquids are dosed, that is to say against the gas pressure inside the feedline 110 and the distributor lines 106, 107. Since the system is closed in a gas-tight and pressure-tight manner, the gas pressure in the reservoir volume is increased, which is formed by the feed line 110 and the distributor lines 106, 107. The geometry of the feed line 110 and the distributor lines 106, 107 is formed in such a way that the gas can flow past the dosed liquid, such that the gas accumulates in the upper part of the supply volume. In the ejection process, pressurised air is supplied with a pressure in the upper part of the reservoir volume by means of the air supply 103. At the same time, the blocking devices 106a, 107a are opened. The pressure of the pressurised air is, in particular, greater than the pressure of the compressed gas in the reservoir volume. However, it can also be lower than the pressure of the compressed gas in the reservoir volume, since opening the blocking devices 106a, 107a leads to a pressure drop of the gas in the upper part of the reservoir volume. The liquid is then forced out of the reservoir volume by the pressurised air.

[0100] In further exemplary embodiments, it is provided that the storage container 4, 204 is not formed in a gas-tight manner, but rather has further openings, for example. In this case, when introducing the liquids, an increased internal gas pressure is not constructed, and the amount of liquid introduced must be measured in a different way. In this case, a float can be used, for example, in order to detect the volume of the liquid introduced. Furthermore, a flow path sensor is provided which measures the volume of one of the liquids introduced, for example the volume of the detergent supplied. Using the total volume and the volume of the second liquid, the mixing ratio can be determined, and the introduction is correspondingly adjusted. If it is ascertained that the predetermined total volume and the predetermined mixing ratio have been reached, the ejection of the mixture from the storage container 4, 204 is initiated, for example by means of a pump. Alternatively, the supply container 4, 204 can be closed in a gas tight manner for the ejection, and an ejection can be carried out by means of pressurised air, as described above.

LIST OF REFERENCE NUMERALS

[0101] 1, 101, 201 First supply line, water supply [0102] 1a, 101a, 201a Check valve [0103] 1b, 101b, 201b Needle valve, throttle [0104] 201c Electromagnetic water valve [0105] 2, 102, 202 Second supply line, chemical supply [0106] 2a, 102a, 202a Check valve [0107] 3, 103, 203 Air supply [0108] 3a, 103a, 203a Check valve [0109] 4, 204 Storage container [0110] 5, 105, 205 Branching line, T-piece [0111] 6, 7, 106, 107, 206, 207 Distributor line [0112] 106a, 107a Blocking device, overpressure valve [0113] 8, 9, 108, 109 Ejection element, nozzle [0114] 10, 110, 210 Feed line [0115] 11, 211 Supply opening [0116] 12, 212 Removal opening [0117] 15, 215 Blocking device, blocking valve [0118] 116, 117 Pressure bladder [0119] 222 Supply unit, electrical dosing pump [0120] 222a Pressure detection element [0121] 223 Removal device, gas supply unit [0122] 230 Control unit [0123] 231 Detection unit