DISHWASHER WITH A TANK CLEANING SYSTEM

Abstract

A warewasher includes at least one washing system configured as a recirculation loop, wherein the washing system includes a nozzle system having at least one washing nozzle for spraying washing liquid onto washware, a washing tank for collecting at least a portion of the sprayed washing liquid, and a washing pump for feeding washing liquid collected in the washing tank to the at least one washing nozzle. A tank cleaning system has at least one cleaning nozzle arranged in or on the washing tank in such a way that, as needed and/or at the end of a washing shift or washing day of the warewasher, a cleaning liquid can be sprayed inside the washing tank or can be sprayed into the washing tank via the at least one cleaning nozzle of the tank cleaning system for cleaning the washing tank and/or components accommodated in the washing tank.

Claims

1. A warewasher having at least one washing system configured as a recirculation loop, wherein the at least one washing system comprises a nozzle system having at least one washing nozzle for spraying washing liquid onto the washware, a washing tank for collecting at least a portion of the sprayed washing liquid, and a washing pump for feeding washing liquid collected in the washing tank to the at least one washing nozzle, wherein the warewasher comprises a tank cleaning system associated with the washing tank and having at least one cleaning nozzle arranged in or on the washing tank in such a way that, as needed and/or at the end of a washing shift or a washing day of the warewasher, a cleaning liquid can be sprayed inside the washing tank or can be sprayed into the washing tank via the at least one cleaning nozzle of the tank cleaning system for cleaning the washing tank and/or components accommodated in the washing tank.

2. The warewasher according to claim 1, wherein the warewasher comprises a dirt collection system associated with the washing tank and having a tank cover screen, wherein the tank cover screen is configured so as to separate dirt particles from the washing liquid that has been sprayed and flows back into the washing tank due to gravity, wherein the at least one cleaning nozzle of the tank cleaning system is arranged in the washing tank below the tank cover screen .

3. The warewasher according to claim 2, wherein the at least one cleaning nozzle of the tank cleaning system is arranged in the washing tank and/or is configured so as to apply the cleaning liquid to a bottom of the tank cover screen, at least in some regions, as needed and at the end of the washing shift or the washing day of the warewasher.

4. The warewasher according to claim 2, wherein the dirt collection system comprises a dirt collection region that is arranged at least partially or regionally in the washing tank and opens upwardly for collecting the dirt particles separated from the washing liquid by means of the tank cover screen, and wherein the at least one cleaning nozzle of the tank cleaning system is arranged in the washing tank and/or configured so as to apply the cleaning liquid to the dirt collection region, at least in some regions, as needed and at the end of the washing shift or the washing day of the warewasher.

5. The warewasher according to claim 4, wherein the dirt collection region comprises a wall region that is permeable to the washing liquid, and wherein the at least one cleaning nozzle of the tank cleaning system is arranged in the washing tank and/or configured so to apply the cleaning liquid to the washing liquid-permeable wall region of the dirt collection region, at least in some regions, as needed and at the end of the washing shift or the washing day of the warewasher.

6. The warewasher according to claim 4, wherein the warewasher further comprises a dirt discharge system fluidly connected to the dirt collection region and having a dirt discharge pipe system, via which the dirt collection region of the warewasher can be emptied as needed.

7. The warewasher according to claim 4, wherein the tank cover screen is arranged over the dirt collection region and comprises a discharge slope towards a feed opening, wherein the dirt collection region which is configured so as to open upwardly is arranged below the feed opening of the tank cover screen, such that the dirt particles separated from the washing liquid by means of the tank cover screen arrive at the dirt collection region via the feed opening.

8. The warewasher according to claim 7, wherein the tank cover screen is configured with a funnel-like region, at least regionally, and wherein the feed opening is configured within the funnel-like region of the tank cover screen.

9. The warewasher according to claim 1, wherein at least one sensor for monitoring the fill plane and/or at least one heating element are arranged at least partially or regionally in the washing tank, and wherein the at least one cleaning nozzle of the tank cleaning system is arranged in the washing tank and/or configured so as to apply cleaning liquid to the at least one sensor and/or the at least one heating element, at least regionally, as needed and at the end of the washing shift or the washing day of the warewasher.

10. The warewasher according to claim 1, wherein the at least one cleaning nozzle of the tank cleaning system or all cleaning nozzles of the tank cleaning system, is/are integrated or arranged in at least one side wall region of the washing tank.

11. The warewasher according to claim 10, wherein the washing tank has a depth that is defined between an upper plane, in which an edge region of a tank cover screen associated with the washing tank lies, and a lower plane, in which a bottom surface of the washing tank forming the floor of the washing tank lies, and wherein the at least one cleaning nozzle, and the side wall region is an upper side wall region of the washing tank.

12. The warewasher according to claim 11, wherein the upper side wall region. lies in a range between 55% and 85% of the depth

13. The warewasher according to claim 1, wherein the at least one washing system is at least partially or regionally accommodated in a treatment chamber or in a treatment zone of the warewasher, wherein the treatment chamber or treatment zone of the warewasher comprises an access opening that is manually lockable, and wherein at least one cleaning nozzle of the tank cleaning system is arranged in or at a side wall region of the washing tank lying opposite the access opening.

14. The warewasher according to claim 1, wherein the tank cleaning system comprises a control device, or wherein a control device is associated with the tank cleaning system, wherein the control device is configured so as to actuate the tank cleaning system as needed or according to a previously defined or definable sequence of events in such a way that the cleaning liquid is sprayed inside the washing tank or is sprayed into the washing tank via the at least one cleaning nozzle of the tank cleaning system.

15. The warewasher according to claim 1, wherein a waste water pump is associated with the washing tank of the warewasher, the suction side of which is or can be fluidly connected to the washing tank in order to pump at least a portion of the washing liquid received in the washing tank, as needed and/or after a previously defined or definable sequence of events, out of the washing tank and then to feed the at least one pumped portion of the washing liquid received in the washing tank to a heat exchanger of the warewasher or a waste water port of the warewasher or a waste water regeneration device of the warewasher.

16. The warewasher according to claim 14, wherein the control device is configured so as to actuate the tank cleaning system, such that the cleaning liquid is sprayed inside the washing tank or sprayed into the washing tank via the at least one cleaning nozzle of the tank cleaning system when at least a portion of the washing liquid received in the washing tank is pumped out by means of the waste water pump.

17. The warewasher according to claim 14, wherein the warewasher comprises a sensor, which is configured so as to detect a level of soiling of the washing liquid received in the washing tank, wherein the control device is configured so as to determine, as a function of the detected level of soiling of the washing liquid received in the washing tank, a time and/or a time period when or during which, by means of the at least one cleaning nozzle of the tank cleaning system, the cleaning liquid is to be sprayed, and/or an amount of cleaning liquid to be sprayed per unit of time by means of the at least one cleaning nozzle of the tank cleaning system.

18. The warewasher according to claim 17, wherein the washing tank is associated with a sensor which is configured so as to at least indirectly detect the level of soiling of the washing liquid received in the washing tank by means of a turbidity of the washing liquid received in the washing tank and/or by means of a washing liquid fill level of the washing liquid received in the washing tank.

19. The warewasher according to claim 1, wherein the cleaning liquid to be sprayed as needed by the at least one cleaning nozzle of the tank cleaning system comprises fresh water or fresh water and a correspondingly metered cleaning chemical.

20. The warewasher according to claim 1, wherein the tank cleaning system comprises a liquid feed that is or can be fluidly connected to the at least one cleaning nozzle of the tank cleaning system, via which the at least one cleaning nozzle of the tank cleaning system can be supplied as needed with the cleaning liquid to be sprayed.

21. The warewasher according to claim 20, wherein the liquid feed of the tank cleaning system comprises at least one valve that can be actuated via a control device of the warewasher and/or at least one cleaning liquid pump that can be actuated via a control device of the warewasher, via which an amount of cleaning liquid to be fed or supplied per unit of time to the at least one cleaning nozzle of the tank cleaning system can be set.

22. The warewasher according to claim 1, wherein the at least one cleaning nozzle of the tank cleaning system is designed as a rotary nozzle and is configured so as to generate a rotating spray jet.

23. The warewasher according to claim 22, wherein the at least one cleaning nozzle comprises a housing having a fluid inlet and a rotor rotatably mounted in or on the housing, having two outlet openings lying at least partially opposite one another.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0066] The invention is described in further detail below with reference to the accompanying drawings.

[0067] The following are shown:

[0068] FIG. 1 is a hydraulic diagram of an exemplary embodiment of the warewasher according to the present invention;

[0069] FIG. 2A shows schematically and in an exploded view, an exemplary embodiment of a screen system used in the warewasher according to the invention;

[0070] FIG. 2B shows schematically and in an isometric view, the screen system according to FIG. 2A in the assembled state;

[0071] FIG. 3 shows schematically, and in an isometric view, an exemplary embodiment of a warewasher designed as a hood-type warewasher with an exemplary embodiment of a tank cleaning system, without a corresponding screen system;

[0072] FIG. 4 shows schematically and in a plan view from above, the washing tank of the warewasher according to FIG. 3;

[0073] FIG. 5 shows schematically and in a partially sectional side view, the lower region of the warewasher according to FIG. 3 having the washing tank, a dirt collection system at least partially or in some regions received in the washing tank, and the tank cleaning system; and

[0074] FIG. 6 shows schematically and in a side view, the lower region of the warewasher according to FIG. 5, without the dirt collection region of the dirt collection system.

DETAILED DESCRIPTION

[0075] Commercial warewashers 1 are designed for cleaning large quantities of washware in as short a time as possible. In a hood-type warewasher from the present applicant, the duration of the preset standard program, which is typically used for normally soiled washware such as plates, bowls, cups, and glasses, is only 70 seconds. This means that the theoretical capacity of the hood-type warewasher is up to 52 baskets per hour.

[0076] Almost without exception, commercial warewashers 1 are equipped with rotating washing-and-rinsing systems. A washing-and-rinsing system typically consists of a washing arm and a rinsing arm 6, 7.

[0077] For example, as shown in FIG. 1, a commercial warewasher 1 has an upper as well as a lower washing and rinsing system.

[0078] During operation, the washing liquid (detergent solution) is pumped from the washing tank of the warewasher 1 to the washing arms 6 via a pipe system using a washing pump 4. The washing arms 6 are used in order to apply the washing liquid (detergent solution) to the washware to be cleaned. The dirt is removed from the washware and integrated into the washing liquid. As shown in FIG. 1, the washing liquid then flows back into the washing tank 3 of the warewasher 1 via a screen system (tank cover screen 14) that retains coarse dirt residues.

[0079] As shown in FIG. 2, the screen system of a commercial warewasher 1 typically comprises a flat screen (tank cover screen 14), a fine screen 16, and a collection tank (dirt collection region 15) for coarse food residues. The collection tank is also commonly referred to as the dirt collection region 15.

[0080] However, systems are also known in which the collection tank (dirt collection region 15) and the fine screen 16 are combined in one part.

[0081] Typically, the flat screen (tank cover screen 14) is formed as a perforated sheet. However, flat screens (tank cover screens 14) without perforations are also known.

[0082] Typically, the flat screen (tank cover screen 14) comprises perforations of 1.5 mm to 3.0 mm in diameter. However, this means that dirt particles that are less than 1.5 mm to 3.0 mm cannot be filtered out of the detergent solution. In subsequent wash programs, these are repeatedly pumped by the washing pump 4 via the washing arms 6. This allows these dirt particles to disperse and settle in the machine interior.

[0083] Coarser dirt particles (3.0 mm to 7.0 mm) are filtered out via the flat screen (tank cover screen 14) and the fine screen 16. The particles of this size are supplied via the drain pump (waste water pump 25), for example, to a waste water system. Dirt residues larger than 7.0 mm are collected in a collection tank (dirt collection region 15). This must be manually removed and cleaned at the end of the washing shift.

[0084] At the end of the washing shift, a special draining program is typically used in which the dirty water is pumped from the machine via the waste water pump 25 and flushed out of the machine interior and the top of the flat screen 14 via the rinsing system. Systems are also known in which the dirty water is drained only by removal of the respective standpipe.

[0085] During the draining program, the top side of the flat screen 14 is cleaned at least in regions and the dirt is rinsed into the collection tank (dirt collection region 15). The flat screen 14 covers the washing tank 3 during the draining program, whereby the washing tank 3 and the bottom of the flat screen 14 are not rinsed.

[0086] After the draining program, the operator is required to clean the warewasher 1 manually. To this end, the washing and rinsing arms and the components of the screen system (flat screen 14, fine screen 16 and dirt collection containers) are usually removed from the warewasher 1 and cleaned manually.

[0087] Furthermore, the machine interior including the washing tank 3 is cleaned with a relatively high manual effort. To this end, the operator usually cleans the interior including the washing tank 3 with a sponge. In the case of stubborn soiling, a brush is first used. Depending on the installation, manual spraying of the machine interior with a water hose/handheld shower is also a common practice.

[0088] The objective of the invention is to eliminate the manual cleaning effort in the area of washing tank 3 and thus significantly reduce the manual cleaning effort for the operator for the entire warewasher 1.

[0089] With the invention, the operator only has to remove, empty and clean the coarse dirt collection tank (dirt collection region 15) during the daily cleaning of the warewasher 1. This is to be implemented by a special cleaning program, which is used at the end of the washing shift in place of the previous draining program.

[0090] The aforementioned particles, which have been deposited on the surfaces, in particular of the washing tank 3, are dissolved and rinsed in the washing tank 3 and from parts of the screen system via cleaning nozzles 20 of a tank cleaning system, so that they can be conveyed from the warewasher 1 via the draining system.

[0091] In the following detailed description of the figures, the same or similarly acting components are provided with the same reference characters.

[0092] In FIG. 1, an exemplary embodiment of the warewasher 1 according to the invention is illustrated. It should be noted that this comprises only the components required for understanding the invention. Details of the warewasher 1 are subsequently illustrated with reference to the illustrations in FIG. 2A, B, and FIG. 3 through FIG. 6.

[0093] The warewasher 1 according to FIG. 1 is in particular a commercial table or utensil washer, which is configured as a hood-type warewasher.

[0094] Of course, it is also possible to configure the warewasher 1 according to the invention as a box-type warewasher or as a conveyor warewasher. The structural changes necessary for this are of course known to the person skilled in the art.

[0095] The warewasher 1 shown in FIG. 1 comprises a treatment chamber 2 with an associated wash tank 3. The wash tank 3 serves to receive a treatment liquid, which can be conveyed to a plurality of washing nozzles 5 via a washing pump 4. In particular, according to the illustrated embodiment, the wash nozzles 5 are located in the upper and lower regions of the treatment chamber 2, where a wash/rinse system with an associated washing arm 6 and a rinsing arm 7 is provided.

[0096] The upper and lower washing arms 6 are connected to the washing tank 3 via a wash line. Because the wash tank 3 is located in the lower region of the treatment chamber 2, this can result in a recirculation of the treatment liquid (wash liquid) after the spraying of the washware.

[0097] The warewasher 1 shown in FIG. 1 further comprises at least one rinsing system for providing a rinsing liquid. In the illustrated embodiment, the rinsing system consists of a reservoir 9 that contains a rinsing concentrate.

[0098] As can be seen from the illustration in FIG. 1, the reservoir 9 of the rinsing system is connected to a water heater (boiler 10) via a fluid line. The boiler 10 comprises a fresh water connection 11 through which fresh water (e.g. tap water) can be introduced into the boiler 10. The fresh water located in the boiler 10 is heated by a heating device and mixed with the rinsing concentrate of the reservoir 9. For this purpose, the rinsing concentrate is conveyed through a dosing pump from the reservoir 9 to the boiler 10. The rinsing liquid resulting from a combination of fresh water and rinsing concentrate can be conveyed to a plurality of rinsing nozzles 13 via a rinsing pump 12 and the associated rinsing lines. Similar to the washing nozzles 5, the rinsing nozzles 13 are also located inside the treatment chamber 2 of the warewasher 1, namely in an upper and lower rinsing arm 7, respectively.

[0099] As can in particular be seen in the illustrations in FIG. 3 to FIG. 6, the exemplary embodiment of the warewasher 1 according to the invention shown schematically in the drawings comprises a tank cleaning system associated with the washing tank 3.

[0100] The tank cleaning system comprises a plurality of cleaning nozzles 20 disposed in the washing tank 3, which are configured, in particular as needed and preferably at the end of a washing shift or a washing day of the warewasher 1 to spray cleaning liquid into the washing tank 3 or to spray the washing tank 3 to clean the washing tank 3 and components accommodated in the washing tank 3 accordingly.

[0101] In so doing, the cleaning nozzles 20 of the tank cleaning system are preferably disposed below the tank cover screen 14, as indicated in FIG. 5 and FIG. 6. Thus, with the aid of the cleaning nozzles 20, the cleaning liquid is applied to a bottom side of the tank cover screen 14 at least in regions.

[0102] The dirt collection region 15 of the dirt collection system can be seen in a side view in FIG. 5.

[0103] The dirt collection region 15 is open towards the top and serves to collect the dirt particles separated from the washing liquid by means of the tank cover screen 14. It is provided that the cleaning nozzles 20 of the tank cleaning system are disposed and configured in the washing tank 3 in order to also apply the cleaning liquid to the dirt collection region 15, if necessary.

[0104] It can also be seen in the illustration in FIG. 5 that the dirt collection region 15 comprises a wall area in the form of a fine screen 16. Cleaning liquid is also applied to this fine screen 16 if necessary using the cleaning nozzle 20 of the tank cleaning system.

[0105] The hydraulic diagram according to FIG. 1 shows that a dirt discharge pipe system 17 can be fluidly connected to the dirt collection region 15, via which the dirt collection region 15 can be emptied as needed. In this respect, the tank cover screen 14 (not shown in FIG. 1) is disposed over the dirt collection region 15 andas shown in FIG. 2A and FIG. 2Bcomprises a drain slope towards a feed opening 18. The dirt collection region 15 is disposed below the feed opening 18 such that the dirt particles separated from the washing liquid via the feed opening 18 enter the dirt collection region 15 with the aid of the tank cover screen 14.

[0106] At least one sensor 19 for level monitoring and at least one heating element can be disposed at least partially or in regions in the washing tank 3 of the warewasher 1. The cleaning nozzles 20 of the tank cleaning system should also be disposed and configured in the washing tank 3 in order to be able to also apply cleaning liquid to the at least one sensor 19 or the at least one heating element as needed.

[0107] In the embodiment shown in the drawings (cf. in particular FIG. 3 to FIG. 6) of the warewasher 1 according to the invention, the cleaning nozzles 20 of the tank cleaning system are disposed or integrated in corresponding side wall areas of the washing tank 3. The cleaning nozzles 20 are in particular disposed in an upper level of the corresponding side wall region of the washing tank 3.

[0108] In FIG. 6, a top level A of the washing tank 3, in which an edge area of a tank cover screen 14 associated with the washing tank 3 lies, is shown, along with a bottom level B, in which a bottom surface of the washing tank 3, which forms the base of the washing tank 3. The distance between these two levels defines the depth T of the washing tank 3.

[0109] In particular, it is provided that the cleaning nozzles 20 are disposed and particularly integrated in a side wall region of the washing tank 3, which lies in a range between 55% and 85% of the depth T and in particular between 60% and 75% of the depth T, as measured from the bottom surface of the washing tank 3 forming the base of the washing tank 3.

[0110] At least some of the cleaning nozzles 20 of the tank cleaning system should be disposed in a side wall region of the washing tank 3, which is disposed opposite an access opening of the warewasher 1 (cf. the top plan view in FIG. 4).

[0111] The tank cleaning system comprises a control device 50 (e.g., any circuit (e.g., solid state, application specific integrated circuit (ASIC), an electronic circuit, a combinational logic circuit, a field programmable gate array (FPGA)), processor(s) (e.g., shared, dedicated, or groupincluding hardware or software that executes code), software, firmware and/or other components, or a combination of some or all of the above, that carries out the control functions of the machine or the control functions of any component thereof) indicated on the schematic drawing, which is configured so as to actuate the tank cleaning system as needed or according to a previously defined or definable sequence of events in such a way that the cleaning liquid is sprayed inside the washing tank 3 via the cleaning nozzles 20 of the tank cleaning system.

[0112] As already indicated in connection with the hydraulic diagram in FIG. 1, the washing tank 3 is associated with a waste water pump 25, the suction side of which is fluidly connected or connectable to the washing tank 3 in order to pump at least a portion of the washing liquid accommodated in the washing tank 3, in particular as needed, or in particular after a previously defined or devinable sequence of events, from the washing tank 3. The drained washing liquid is supplied to either a heat exchanger of the warewasher 1 (not shown in the drawings) or a drainage connection of the warewasher 1 or a drainage regeneration device of the warewasher 1.

[0113] The control device 50 of the tank cleaning system is in particular configured so as to actuate the tank cleaning system, in particular automatically and preferably selectively automatically, such that the cleaning liquid is sprayed into the washing tank 3 via the cleaning nozzles 20 of the tank cleaning system when at least a portion of the washing liquid received in the washing tank 3 is pumped out by means of the waste water pump 25.

[0114] Alternatively or additionally, the control device 50 is configured to determine a time or a time period for when or during which the cleaning liquid in washing tank 3 is to be sprayed with the aid of the cleaning nozzles 20 of the tank cleaning system, depending on a degree of soiling of the washing fluid received in the washing tank 3 detected using sensors.

[0115] The control device 50 may also be configured to establish an amount of cleaning liquid to be sprayed per unit of time using the cleaning nozzles 20 of the tank cleaning system, depending on the degree of soiling of the washing liquid received in washing tank 3 detected using sensors.

[0116] The soiling or degree of soiling of the washing liquid received in the washing tank 3 can be detected, for example with the aid of a turbidity sensor.

[0117] Alternatively or additionally, the washing liquid level of the washing liquid received in the washing tank 3 may also be used to infer the degree of soiling of the washing liquid received in the washing tank 3.

[0118] Although this is not explicitly illustrated in the drawings, the tank cleaning system comprises a liquid feed that is or can be fluidly connected to the cleaning nozzles 20 of the tank cleaning system, via which the cleaning nozzles 20 of the tank cleaning system can be supplied as needed with the cleaning liquid to be sprayed.

[0119] The cleaning liquid is preferably fresh water, particularly cold fresh water. Alternatively, of course, it is also contemplated to use heated water as the cleaning liquid, in particular heated fresh water, or regenerated washing liquid from the washing tank 3. A cleaning chemical may also be added to the cleaning liquid, if necessary.

[0120] The cleaning nozzles 20 of the tank cleaning system are preferably designed as rotary nozzles and are configured so as to generate a rotating spray jet.

[0121] In particular, the cleaning nozzle 20 comprises a housing 21 having a fluid inlet 22 and a rotor 23 rotatably mounted in or on the housing 21, comprising two outlet openings 24 lying at least partially opposite one another.

[0122] The invention is not limited to the embodiments shown in the drawings, but results when all of the features disclosed herein are considered together.

LIST OF REFERENCE NUMERALS

[0123] 1 Warewasher [0124] 2 Treatment chamber [0125] 3 Washing tank [0126] 4 Washing pump [0127] 5 Wash nozzle [0128] 6 Washing arm [0129] 7 Rinsing arm [0130] 9 Reservoir for rinsing concentrate [0131] 10 Water heater/boiler [0132] 11 Water heater fresh water connection [0133] 12 Rinsing pump [0134] 13 Rinsing nozzle [0135] 14 Tank cover screen [0136] 15 Dirt collection region [0137] 16 Fine screen [0138] 17 Dirt discharge pipe system [0139] 18 Feed opening [0140] 19 Fill level monitoring sensor [0141] 20 Cleaning nozzle [0142] 25 Wastewater pump [0143] 50 Control device 50 [0144] A Upper level of wash tank [0145] B Ground surface/lower level of wash tank [0146] T Depth of wash tank