Dishwasher with a tank cleaning system

Abstract

The invention relates to a dishwasher (1) with at least one washing system designed as a recirculation circuit, wherein the at least one washing system comprises a nozzle system with at least one washing nozzle (5) for spraying washing liquid onto the items to be cleaned, a washing tank (3) for collecting at least one part of the sprayed washing liquid and a washing pump (4) for supplying washing liquid collected in the washing tank (3) to the at least one washing nozzle (5).According to the invention, the dishwasher (1) has a tank cleaning system associated with the wash tank (3) with at least one cleaning nozzle (20) arranged in or on the wash tank (3) such that, in particular as required and preferably at the end of a washing shift or a washing day of the dishwasher (1), a cleaning fluid can be sprayed into the wash tank (3) or injected into the wash tank (3) via the at least one cleaning nozzle (20) of the tank cleaning system for cleaning the wash tank (3) and / or components contained in the wash tank (3).

Description

[0001] The invention relates to a dishwasher according to the preamble of claim 1. Accordingly, the invention relates in particular to a commercial dishwasher or utensil washer, which is designed as a program-controlled automatic dishwasher or as a conveyor dishwasher.

[0002] The invention is thus directed to a dishwasher which has at least one washing zone designed as a recirculation circuit. The washing zone designed as a recirculation circuit has a nozzle system with at least one washing nozzle for spraying washing liquid onto the items to be cleaned, a washing tank for collecting at least part of the sprayed washing liquid, and a washing pump for supplying washing liquid collected in the washing tank to the at least one washing nozzle.

[0003] Optionally, the dishwasher may also have a dirt collection system assigned to at least one washing zone with at least one tank cover sieve to separate dirt particles from the sprayed washing liquid that flows back into the washing tank by gravity.

[0004] Automatic dishwashers are manually loaded and unloaded. These dishwashers (also called "box-type" or "batch dish washers") can be either pass-through dishwashers (hood-type) or front-loading dishwashers. Front-loading dishwashers can be under-counter, top-counter, or freestanding models.

[0005] A dishwasher designed as a program-controlled automatic dishwasher typically has a treatment chamber for cleaning the dishes. Usually, a wash tank is located below the treatment chamber, into which liquid from the treatment chamber can flow back by gravity. The wash tank contains washing fluid, which is usually water, to which detergent can be added if necessary.

[0006] A dishwasher designed as a program-controlled automatic dishwasher further comprises a washing system with a wash pump, a pipe system connected to the wash pump, and a nozzle system with at least one wash nozzle. The washing liquid in the wash tank can be pumped by the wash pump via the pipe system to the at least one wash nozzle, and sprayed by this nozzle onto the items to be cleaned in the treatment chamber. The sprayed washing liquid then flows back into the wash tank by gravity.

[0007] Conveyor dishwashers are primarily belt-type dishwashers (flight-type washers) or rack-type dishwashers. Conveyor dishwashers are typically used in commercial settings. Unlike automatic dishwashers where the items to be cleaned remain stationary during the cleaning process, conveyor dishwashers transport the items through various cleaning zones within the machine.

[0008] A conveyor dishwasher typically has at least one pre-wash zone and at least one main wash zone, which, viewed in the direction of transport, is located downstream of the pre-wash zone(s). Following the main wash zone(s), in the direction of transport, there is usually at least one post-wash zone or pre-rinse zone and at least one rinse zone downstream of the post-wash zone(s). Viewed in the direction of transport, the items, either picked up directly on the conveyor belt or held in baskets, typically pass through an inlet tunnel, the subsequent pre-wash zone(s), main wash zone(s), post-wash zone(s), rinse zone(s), and a drying zone before entering an outlet section.

[0009] Each of the aforementioned washing zones of the conveyor dishwasher is assigned a washing system comprising a wash pump and a pipe system connected to the wash pump (wash pipe system), through which washing fluid is supplied to the nozzle system or at least one of the nozzle system's wash nozzles. The washing fluid supplied to the at least one nozzle of the nozzle system is sprayed onto the items being washed in the respective washing zones of the conveyor dishwasher, which are transported through these zones by a conveyor system. Each washing zone is assigned a tank in which the fluid sprayed by the wash nozzles is collected and / or in which fluid is supplied to the nozzle systems of the respective treatment zones.

[0010] In conventional conveyor dishwashers, rinse aid, in the form of fresh water (which may be pure or contain additives such as rinse aid), is sprayed onto the items being washed via the spray nozzles of the rinse zone. At least a portion of the sprayed rinse aid is transported from zone to zone via a cascade system, in the opposite direction to the transport of the items.

[0011] The sprayed rinse aid is collected in a tank (post-wash tank) in the post-wash zone. From there, it is pumped by the wash pump of the post-wash zone's washing system to the spray nozzles (post-wash nozzles). In the post-wash zone, the wash fluid is rinsed off the items being washed. The resulting liquid flows into the wash tank of at least one main wash zone, which is located upstream of the post-wash zone in the direction of item transport. Here, the liquid is typically mixed with a cleaning agent and sprayed onto the items via the nozzles (wash nozzles) of the main wash zone by a pump system (wash pump) belonging to the main wash zone's washing system. From the main wash zone's wash tank, the liquid then flows—unless another main wash zone is present—into the pre-wash tank of the pre-wash zone.The liquid in the pre-wash tank is sprayed onto the items being washed via a pump system (pre-wash pump) belonging to the pre-wash zone's washing system, using the pre-wash nozzles to remove coarse dirt from the items being washed.

[0012] Dishwashers are typically equipped with pumps that supply the rinse aid to the rinse zone's piping system. This ensures a virtually constant flow rate of rinse aid within the rinse zone. However, it is also possible to utilize the building's existing water pressure – for example, the pressure from the fresh water supply – to deliver the rinse aid to the rinse zone's piping system. In this latter case, a controllable valve can be installed between the piping system and the rinse zone's spray nozzles to allow for temporary or complete interruption of the rinse aid supply to the spray nozzles.

[0013] Regardless of whether a dishwasher is designed as a program-controlled automatic dishwasher or as a conveyor dishwasher, commercial dishwashers typically include at least one washing zone designed as a recirculation circuit, which has a nozzle system with at least one washing nozzle for spraying washing liquid onto the items to be cleaned, a washing tank for collecting at least part of the sprayed washing liquid, and a washing pump for supplying liquid collected in the washing tank to the at least one washing nozzle.

[0014] Since a recirculating wash zone is used to clean the items being washed, at least some of the washing liquid already sprayed in the zone is circulated. This creates the risk that the protective particles removed from the items will be increasingly broken down by the constant recirculation of the washing liquid and thus can no longer be easily separated from the liquid by sieves or other means. Consequently, in a recirculating wash zone, the level of soiling in the washing liquid increases with the washing time, increasing the risk of re-soiling the items and ultimately deteriorating the washing results.

[0015] This problem occurs particularly in the pre-wash or main wash zones of a conveyor dishwasher. Because the flow direction of the wash liquid in conveyor dishwashers is cascading, opposite to the transport direction of the items being cleaned, the dirt concentration in the wash liquid is highest in at least one pre-wash zone compared to the other treatment zones, as this is where most of the dirt accumulates.

[0016] On the other hand, it is unavoidable that during the operation of a transport dishwasher, some of the more heavily soiled wash liquid from the pre-wash zone is carried into the main wash zone (at least one) downstream of the pre-wash zone by the transport of the dishes. This increases the soiling level of the wash liquid in the main wash zone, and consequently, the washing result in the main wash zone can also deteriorate.

[0017] To separate the dirt particles introduced into the dishwasher from the washing liquid used to rinse the dishes, it is generally known to use sieve devices in the form of dirt sieve baskets, in which the dirt particles collected. In dishwashers designed as automatic programs, such a dirt sieve basket is usually located in the sump of the treatment chamber above the wash tank.

[0018] On the other hand, with regard to dishwashers designed as transport dishwashers, it is known to equip at least the pre-wash tank assigned to the pre-wash zone, and preferably also the main wash tank assigned to the at least one main wash zone, with surface sieves and dirt sieve baskets.

[0019] During operation of a dishwasher, whether a program-controlled or conveyor dishwasher, the dirt particles rinsed from the dishes by the circulating wash water fall onto the surface filters due to gravity. There, the dirt particles are separated from the wash liquid, which flows back into the corresponding wash tank. The separated dirt particles are then typically rinsed into a dirt filter basket.

[0020] Regardless of whether the dishwasher is a program-controlled automatic dishwasher, especially a hood-type dishwasher, or a conveyor dishwasher, it must be cleaned at least at the end of each commercial dishwashing day or at the end of a dishwashing shift. This involves a number of manual steps.

[0021] To clean a conveyor dishwasher, for example, the wash arms and the filter systems of the individual wash units must first be removed. Since a conveyor dishwasher typically has several wash zones arranged in series and therefore a corresponding number of wash units, these steps must be repeated several times.

[0022] The removed sieve systems are then manually rinsed with water and additionally scrubbed manually, depending on the degree of soiling.

[0023] In particular, the corresponding wash tanks of the conveyor dishwasher must also be manually rinsed with water and, if necessary, scrubbed. The wash tanks in the loading area of ​​a conveyor dishwasher, which are among the most heavily soiled treatment zones, are rinsed with water during the cleaning process and partially (if necessary) cleaned manually with a cleaning cloth and, if required, with the aid of a cleaning solution.

[0024] After the individual treatment zones of a transport dishwasher have been completely emptied, each treatment zone and especially each wash tank of each treatment zone is usually rinsed with warm water at the end of each washing day and partially (if necessary) manually cleaned with a cleaning cloth and possibly with the help of a cleaning solution.

[0025] Interior cleaning also includes the corresponding inspection doors of a transport dishwasher, which are usually designed as sliding doors or hinged doors.

[0026] Depending on the machine size, the entire cleaning process for a transport dishwasher takes between 30 and 40 minutes, with the amount of fresh water used for cleaning ranging from 400 liters to 600 liters.

[0027] Cleaning a program-controlled dishwasher, especially a hood-type dishwasher, at the end of a commercial dishwashing day requires at least the wash tank to be cleaned in a similar manner. This also involves a large number of manual steps.

[0028] To clean a pass-through dishwasher, for example, the wash and rinse arms of the washing system, as well as the filter system, must first be removed. The removed filter system is then manually rinsed, usually with warm water, and additionally scrubbed manually, depending on the degree of soiling. Furthermore, the dishwasher's treatment chamber, after it has been completely emptied, should be rinsed, usually with warm water, and also partially cleaned manually (if necessary) with a cleaning cloth and, if required, with the help of a cleaning solution.

[0029] Depending on the machine size, the entire interior cleaning process of a pass-through dishwasher takes between 10 and 30 minutes, with the amount of fresh water used for cleaning ranging from 60 liters to 120 liters.

[0030] The present invention aims to provide a dishwasher of the type mentioned at the outset, in which the cleaning process, particularly at the end of a commercial dishwashing day, can be made more efficient. In particular, the invention aims to provide a dishwasher in which at least some of the steps required for cleaning the interior of the dishwasher can be simplified or even eliminated, thereby saving personnel and simultaneously reducing the resources (water, energy, chemicals) used for cleaning.

[0031] The problem underlying the invention is solved by the subject matter of independent claim 1, wherein advantageous further developments of the dishwasher according to the invention are specified in the dependent claims.

[0032] Accordingly, the invention relates in particular to a dishwasher with at least one washing system designed as a recirculation circuit. The dishwasher according to the invention is in particular a dishwashing or utensil washing machine, which is designed either as a program-controlled automatic dishwasher or as a conveyor dishwasher.

[0033] The at least one washing system of the dishwasher according to the invention has a nozzle system with at least one washing nozzle for spraying washing liquid onto the items to be cleaned, a washing tank for collecting at least part of the sprayed washing liquid and a washing pump which serves to supply washing liquid collected in the washing tank to the at least one washing nozzle.

[0034] According to the invention, it is particularly provided that the dishwasher has a tank cleaning system associated with the wash tank, with at least one cleaning nozzle arranged in or on the wash tank such that, particularly as required and preferably at the end of a washing shift or a washing day of the dishwasher, a cleaning fluid can be sprayed into the wash tank or injected into the wash tank via the at least one cleaning nozzle of the tank cleaning system for cleaning the wash tank and / or components contained in the wash tank.

[0035] The advantages achievable with the solution according to the invention are obvious. Because the dishwasher has a tank cleaning system associated with the wash tank, the manual cleaning effort in the area of ​​the wash tank is eliminated or at least significantly reduced in a simple yet effective manner. This significantly reduces the manual cleaning effort for the dishwasher operator for the entire machine.

[0036] With the solution according to the invention, the operator of the dishwasher only needs to remove, empty and clean a coarse dirt collection container from the dishwasher during daily cleaning.

[0037] In a preferred embodiment of the solution according to the invention, the dishwasher has a dirt collection system associated with the wash tank, comprising a tank cover screen. The tank cover screen is designed to separate dirt particles from the sprayed washing liquid that flows back into the wash tank by gravity. In particular, the at least one cleaning nozzle of the tank cleaning system is arranged in the wash tank below the tank cover screen.

[0038] Preferably, the at least one cleaning nozzle of the tank cleaning system is arranged in the wash tank and / or designed in such a way as to apply the cleaning fluid to the underside of the tank cover screen, at least partially, particularly as required and preferably at the end of a washing shift or a washing day of the dishwasher.

[0039] According to further developments of the last-mentioned embodiments of the dishwasher according to the invention, it is provided that the dirt collection system of the dishwasher has a dirt collection area that is at least partially or partially arranged in the wash tank and is open at the top for collecting the dirt particles separated from the wash liquid by means of the tank cover sieve.

[0040] It is advantageous for the at least one cleaning nozzle of the tank cleaning system to be arranged and / or designed in the wash tank in such a way as to, in particular as required and preferably at the end of a washing shift or a washing day of the dishwasher, at least partially apply the cleaning fluid to the dirt collection area of ​​the dirt collection system.

[0041] In a preferred further development of the last-mentioned embodiment of the dishwasher according to the invention, it is provided that the dirt collection area of ​​the dirt collection system has a wall area permeable to washing liquid, in particular in the form of a sieve and preferably in the form of a fine sieve.

[0042] The at least one cleaning nozzle of the tank cleaning system should be arranged and / or designed in the wash tank in such a way as to apply the cleaning fluid, at least partially, to the wall area of ​​the dirt collection area that is permeable to washing fluid, particularly as required and preferably at the end of a washing shift or a washing day of the dishwasher.

[0043] According to implementations of the dirt collection system associated with the wash tank of the dishwasher according to the invention, the dishwasher further provides a dirt discharge system with a dirt discharge pipe system, which is flow-connected to the dirt collection area of ​​the dirt collection system and through which the dirt collection area can be emptied as required.

[0044] In particular, according to implementations of the dishwasher according to the invention, the tank cover sieve is arranged above the dirt collection area and has a drainage slope towards a feed opening. It is advantageous for the dirt collection area, which is open at the top, to be arranged below the feed opening in such a way that the dirt particles separated from the washing liquid by the tank cover sieve enter the dirt collection area via the feed opening.

[0045] In this context, it is particularly advantageous for the tank cover screen to be funnel-shaped at least in some areas, with the feed opening being located within the funnel-shaped area of ​​the tank cover screen and preferably in a tapered area of ​​the funnel-shaped area of ​​the tank cover screen.

[0046] According to implementations of the dishwasher according to the invention, it is provided that at least one sensor for monitoring the fill level and / or at least one heating element are arranged at least partially or in certain areas in the wash tank of the dishwasher.

[0047] In this context, the at least one cleaning nozzle of the tank cleaning system should be arranged and / or designed in the wash tank in such a way as to, in particular as required and preferably at the end of a washing shift or a washing day of the dishwasher, apply the cleaning fluid to the at least one sensor and / or the at least one heating element at least partially.

[0048] Preferably, the at least one cleaning nozzle of the tank cleaning system is arranged and, in particular, integrated in a side wall region of the wash tank. In particular, according to embodiments of the dishwasher according to the invention, all cleaning nozzles of the tank cleaning system are arranged and, in particular, integrated in corresponding side wall regions of the wash tank.

[0049] An upper level of the wash tank can be defined by the fact that an edge region of a tank cover screen associated with the wash tank lies within this level. A lower level of the wash tank can be defined by the bottom surface of the wash tank forming its base. The distance between the lower level and the upper level defines the depth T of the wash tank.

[0050] In embodiments of the dishwasher according to the invention, it is provided that the at least one cleaning nozzle and preferably all cleaning nozzles of the tank cleaning system are arranged and in particular integrated in an upper side wall area of ​​the wash tank.

[0051] Particularly efficient tank cleaning can be achieved with the help of at least one cleaning nozzle if the at least one cleaning nozzle is arranged and, in particular, integrated in a side wall area of ​​the wash tank which – measured from the bottom surface of the wash tank forming the base of the wash tank – lies in an area between 55% and 85% of the depth T and, in particular, in an area between 60% and 75% of the depth T.

[0052] The tank cleaning system should be designed to clean areas of the wash tank that are difficult for the dishwasher operator to access. Therefore, the at least one washing system is provided for, at least partially or completely, within a treatment chamber or treatment zone of the dishwasher, the treatment chamber or treatment zone of the dishwasher having an access opening that can be manually closed. In this context, the at least one cleaning nozzle of the tank cleaning system should be located in or on a side wall area of ​​the wash tank opposite the access opening of the dishwasher or the treatment chamber or treatment zone of the dishwasher.

[0053] According to one aspect of the present invention, the tank cleaning system includes a control device. Alternatively, it is conceivable that a control device is associated with the tank cleaning system.

[0054] The control device is designed to control the tank cleaning system as required or according to a predetermined or definable sequence of events in such a way that the cleaning fluid is sprayed into the wash tank via at least one cleaning nozzle of the tank cleaning system.

[0055] A wastewater pump may be assigned to the wash tank, the suction side of which is or can be connected to the wash tank in terms of flow, in order to pump out at least a part of the washing liquid contained in the wash tank, particularly as required or in particular according to a predetermined or definable sequence of events, and to supply the pumped-out, at least part of the washing liquid contained in the wash tank to a heat exchanger of the dishwasher or a wastewater connection of the dishwasher or a wastewater regeneration device of the dishwasher.

[0056] In this context, it is advantageous for the control device of the tank cleaning system to be designed to control the tank cleaning system preferably automatically and, in particular, optionally automatically, in such a way that the cleaning fluid is sprayed into the wash tank via the at least one cleaning nozzle of the tank cleaning system when at least part of the wash fluid absorbed in the wash tank is pumped out or has been pumped out by means of the wastewater pump.

[0057] Alternatively or additionally, it is conceivable that the dishwasher has sensors designed to detect the degree of soiling of the washing liquid held in the wash tank.

[0058] In this context, it is advisable that the control device be designed to determine, depending on the detected degree of contamination of the washing liquid contained in the washing tank, a time and / or a duration during which the cleaning liquid is to be sprayed, particularly as required, using the at least one cleaning nozzle of the tank cleaning system.

[0059] Alternatively or additionally, the control device should be designed to determine, depending on the detected degree of contamination of the washing liquid contained in the washing tank, an amount of cleaning liquid to be sprayed per unit of time using at least one cleaning nozzle of the tank cleaning system.

[0060] According to embodiments of the dishwasher according to the invention, a sensor is assigned to the wash tank which is designed to detect the degree of contamination of the wash liquid held in the wash tank at least indirectly, based on the turbidity of the wash liquid held in the wash tank and / or on the level of the wash liquid held in the wash tank.

[0061] The cleaning fluid, which is sprayed as needed with the at least one cleaning nozzle of the tank cleaning system, is preferably fresh water, in particular cold fresh water, heated water, in particular heated fresh water, or regenerated washing fluid from the wash tank. A cleaning chemical may optionally be added to the cleaning fluid.

[0062] The tank cleaning system preferably has a fluid supply that is or can be connected to the at least one cleaning nozzle via a flow path, and through which the cleaning fluid to be sprayed by the cleaning nozzle can be supplied to the at least one cleaning nozzle as required.

[0063] In this context, it is advisable that the liquid supply of the tank cleaning system has at least one valve controllable via a control unit of the dishwasher and / or at least one cleaning fluid pump controllable via a control unit of the dishwasher, via which the quantity of cleaning fluid to be supplied or supplied per unit of time to the at least one cleaning nozzle of the tank cleaning system can be set.

[0064] With regard to the at least one cleaning nozzle of the tank cleaning system, it has proven particularly advantageous if the cleaning nozzle is designed and configured as a rotary nozzle to produce a rotating spray jet.

[0065] According to the implementations of the at least one cleaning nozzle of the tank cleaning system, it is provided that the at least one cleaning nozzle has a housing with a fluid inlet and a rotor rotatably mounted in or on the housing with two outlet openings that are at least partially opposite each other.

[0066] Of course, other designs for the cleaning nozzle of the tank cleaning system are also conceivable.

[0067] The invention is described in more detail below with reference to the accompanying drawings.

[0068] They show: FIG. 1 A hydraulic diagram of an exemplary embodiment of the dishwasher according to the invention; FIG. 2A Schematic and in an exploded view an exemplary embodiment of a sieve system used in the dishwasher according to the invention; FIG. 2B Schematic and in an isometric view the sieve system according to FIG. 2A in the assembled state; FIG. 3 schematically and in an isometric view an exemplary embodiment of a hood-type dishwasher with an exemplary embodiment of a tank cleaning system, without a corresponding sieve system; FIG. 4 schematically and in a top view the wash tank of the dishwasher according to FIG. 3 ; FIG. 5 schematically and in a partially cut-away side view the lower area of ​​the dishwasher according to FIG. 3 with the wash tank, a dirt collection system at least partially or partially incorporated into the wash tank, and the tank cleaning system; and FIG. 6 schematically and in a side view the lower area of ​​the dishwasher according to FIG. 5 , without the dirt collection area of ​​the dirt collection system.

[0069] Commercial dishwashers are designed to clean large quantities of items in the shortest possible time. For example, the preset standard program of the hood-type dishwasher used by the applicant in this case, which is typically used for normally soiled items such as plates, bowls, cups, and glasses, lasts only 70 seconds. This means that the theoretical capacity of the hood-type dishwasher is up to 52 dish racks per hour.

[0070] Almost without exception, commercial dishwashers are equipped with rotating washing and rinsing systems. A washing and rinsing system typically consists of a washing arm and a rinsing arm.

[0071] For example, in FIG. 1 As shown, a commercial dishwasher 1 has an upper and a lower washing and rinsing system.

[0072] During operation, a wash pump 4 pumps the washing liquid (washing solution) from the dishwasher's wash tank 1 through a pipe system into the wash arms 6. The wash arms 6 then expose the items to be cleaned to the washing liquid (washing solution). This loosens the dirt from the items and transfers it into the washing liquid. The washing liquid then flows, as in FIG. 1 as can be seen, then via a sieve system (tank cover sieve 14), which retains coarse dirt residues, into a wash tank 3 of the dishwasher 1.

[0073] As in FIG. 2 As shown, the filter system of a commercial dishwasher 1 typically comprises a flat filter (tank cover filter 14), a fine filter 16, and a collection container (dirt collection area 15) for coarse food residues. The collection container is also commonly referred to as the dirt collection area 15.

[0074] However, systems are also known in which the collection container (dirt collection area 15) and the fine sieve 16 are combined in one part.

[0075] The surface sieve (tank cover sieve 14) is usually formed as a perforated sheet. However, surface sieves (tank cover sieves 14) without perforations are also known.

[0076] The surface filter (tank cover filter 14) typically has perforations with a diameter of 1.5 mm to 3.0 mm. However, this means that dirt particles smaller than 1.5 mm to 3.0 mm cannot be filtered out of the wash water. These particles are repeatedly pumped by the wash pump 4 over the wash arms 6 in subsequent wash cycles. As a result, these dirt particles can spread and settle inside the machine.

[0077] Larger dirt particles (3.0 mm to 7.0 mm) are filtered out via the surface sieve (tank cover sieve 14) and the fine sieve 16. These particles are then conveyed to a wastewater system, for example, via the drain pump (wastewater pump 25). Dirt residues larger than 7.0 mm are collected in a collection container (dirt collection area 15). This container must be manually removed and cleaned at the end of the rinsing cycle.

[0078] At the end of the rinsing cycle, a special pumping program is usually used, in which the wastewater is pumped out of the machine via the wastewater pump 25 and the machine interior and the top of the surface screen 14 are rinsed via the rinsing system. Systems are also known in which the wastewater is drained simply by removing the corresponding standpipe.

[0079] During the draining program, the top of the surface filter 14 is at least partially cleaned, and the dirt is flushed into the collection container (dirt collection area 15). The surface filter 14 covers the wash tank 3 during the draining program, meaning that the wash tank 3 and the underside of the surface filter 14 are not rinsed.

[0080] After the draining program, the operator has the task of manually cleaning dishwasher 1. This usually involves first removing the wash and rinse arms and the components of the filter system (flat filter 14, fine filter 16 and dirt collection container) from dishwasher 1 and cleaning them manually.

[0081] Furthermore, the machine interior, including wash tank 3, requires relatively extensive manual cleaning. The operator typically cleans the interior, including wash tank 3, with a sponge. For stubborn dirt, a brush is used first. Depending on the installation, manually rinsing the machine interior with a hose / hand shower is also common practice.

[0082] The aim of the invention is to eliminate the manual cleaning effort in the area of ​​the wash tank 3 and thus to significantly reduce the manual cleaning effort for the operator for the entire dishwasher 1.

[0083] With this invention, the operator only needs to remove, empty, and clean the coarse dirt collection container (dirt collection area 15) during the daily cleaning of the dishwasher 1. This is achieved by a special cleaning program that is used at the end of the wash cycle instead of the previous draining program.

[0084] The particles mentioned above, which have accumulated on the surfaces, especially of the washing tank 3, are loosened and rinsed away via cleaning nozzles 20 of a tank cleaning system in the washing tank 3 and from parts of the sieve system, so that they can be conveyed out of the dishwasher 1 via the drainage system.

[0085] In the following detailed figure description, identical or equivalent components are provided with the same reference symbols.

[0086] In FIG. 1 An exemplary embodiment of the dishwasher 1 according to the invention is shown. It should be noted that this embodiment only includes the components necessary for understanding the invention. Details of the dishwasher 1 are subsequently described with reference to the illustrations in FIG. 2A , B and FIG. 3 bis FIG. 6 described.

[0087] Dishwasher 1 according to FIG. 1 This refers in particular to a commercial dishwasher or utensil washer, which is designed as a hood-type dishwasher.

[0088] Naturally, it is also possible to design the dishwasher 1 according to the invention as a program-controlled automatic dishwasher or as a conveyor dishwasher. The necessary design modifications for this are, of course, known to those skilled in the art.

[0089] The in FIG. 1 The illustrated dishwasher 1 has a treatment chamber 2 with an associated wash tank 3. The wash tank 3 serves to hold a treatment fluid, which can be pumped via a wash pump 4 to a plurality of wash nozzles 5. According to the illustrated embodiment, the wash nozzles 5 are located, in particular, in the upper and lower regions of the treatment chamber 2, where a wash / rinse system with an associated wash arm 6 and a rinse arm 7 is provided in each region.

[0090] The upper and lower washing arms 6 are connected to the washing tank 3 via a washing line. Since the washing tank 3 is located in the lower area of ​​the treatment chamber 2, this allows for recirculation of the treatment fluid (washing fluid) after the items being washed have been sprayed.

[0091] The in FIG. 1 The dishwasher 1 shown further comprises at least one rinse aid system for providing a rinse aid liquid. In the illustrated embodiment, the rinse aid system consists of a reservoir 9 which contains a rinse aid concentrate.

[0092] As the depiction in FIG. 1 The reservoir 9 of the rinse aid system is connected to a water heater (boiler 10) via a fluid line. Boiler 10 has a fresh water connection 11 through which fresh water (e.g., tap water) can be introduced into the boiler 10. The fresh water in the boiler 10 is heated by a heating element and mixed with the rinse aid concentrate from the reservoir 9. For this purpose, the rinse aid concentrate is pumped from the reservoir 9 to the boiler 10 by a dosing pump. The rinse aid solution resulting from the combination of fresh water and rinse aid concentrate can be pumped via a rinse aid pump 12 and the associated rinse aid lines to a number of rinse aid nozzles 13. Similar to the wash nozzles 5, the rinse aid nozzles 13 are also located inside the treatment chamber 2 of the dishwasher 1, specifically in an upper or lower spray arm 7.

[0093] As can be seen in particular in the depictions in FIG. 3 bis FIG. 6 The exemplary embodiment of the dishwasher 1 according to the invention, shown schematically in the drawings, has a tank cleaning system associated with the wash tank 3.

[0094] The tank cleaning system comprises several cleaning nozzles 20 arranged in the wash tank 3, which are designed, in particular as required and preferably at the end of a washing shift or a washing day of the dishwasher 1, to spray or disperse cleaning fluid into the wash tank 3 in order to clean the wash tank 3 and components contained in the wash tank 3 accordingly.

[0095] The cleaning nozzles 20 of the tank cleaning system are preferably arranged below the tank cover screen 14, as shown in FIG. 5 and FIG. 6 This is indicated. With the help of the cleaning nozzles 20, the underside of the tank cover screen 14 is also at least partially exposed to the cleaning fluid.

[0096] The dirt collection area 15 of the dirt collection system is in FIG. 5 visible in a side view.

[0097] The dirt collection area 15 is open at the top and serves to collect the dirt particles separated from the washing liquid by means of the tank cover sieve 14. The cleaning nozzles 20 of the tank cleaning system are arranged and designed in the washing tank 3 in such a way as to also supply the dirt collection area 15 with the cleaning liquid as needed.

[0098] Also the representation in FIG. 5 It can be seen that the dirt collection area 15 has a wall section in the form of a fine screen 16. This fine screen 16 is also supplied with cleaning fluid as needed by means of the cleaning nozzle 20 of the tank cleaning system. According to the hydraulic diagram FIG. 1 It can be seen that a dirt discharge pipe system 17 can be flow-connected to the dirt collection area 15, via which the dirt collection area 15 can be emptied as needed. The tank cover screen 14 (in FIG. 1 (not shown) arranged above the dirt collection area 15 and shows - as shown in FIG. 2A und FIG. 2B The figure shows a slope leading towards a feed opening 18. The dirt collection area 15 is arranged below the feed opening 18 such that the dirt particles separated from the washing liquid by means of the tank cover screen 14 enter the dirt collection area 15 via the feed opening 18.

[0099] The wash tank 3 of the dishwasher 1 can contain at least one sensor 19 for monitoring the fill level and at least one heating element, at least partially or partially. The cleaning nozzles 20 of the tank cleaning system should also be arranged and designed in the wash tank 3 in such a way as to be able to supply the at least one sensor 19 and / or the at least one heating element with cleaning fluid as needed.

[0100] In the embodiment shown in the drawings (see in particular) FIG. 3 bis FIG. 6 In the dishwasher 1 according to the invention, the cleaning nozzles 20 of the tank cleaning system are arranged or integrated in corresponding side wall areas of the wash tank 3. The cleaning nozzles 20 are arranged, in particular, in an upper plane of the corresponding side wall area of ​​the wash tank 3.

[0101] In FIG. 6 An upper level A of the wash tank 3, in which an edge region of a tank cover screen 14 associated with the wash tank 3 is located, is shown, together with a lower level B, in which a bottom surface of the wash tank 3, forming the base of the wash tank 3, is located. The distance between these two levels defines the depth T of the wash tank 3.

[0102] It is particularly provided that the cleaning nozzles 20 are arranged and in particular integrated in a side wall area of ​​the wash tank 3, which, measured from the bottom surface of the wash tank 3 forming the base, lies in an area between 55% and 85% of the depth T and in particular between 60% and 75% of the depth T.

[0103] At least some of the cleaning nozzles 20 of the tank cleaning system should be arranged in a side wall area of ​​the wash tank 3, which is located opposite an access opening of the dishwasher 1 (see the top view in FIG. 4 ).

[0104] The tank cleaning system has a schematically indicated control device 50, which is designed to control the tank cleaning system as required or according to a predetermined or definable sequence of events in such a way that the cleaning fluid is sprayed into the wash tank 3 via the cleaning nozzles 20 of the tank cleaning system.

[0105] As already mentioned in connection with the hydraulic diagram in FIG. 1 As indicated, a wastewater pump 25 is associated with the wash tank 3, the suction side of which is or can be connected to the wash tank 3 in terms of flow, in order to pump out at least a portion of the washing liquid contained in the wash tank 3, particularly as needed or according to a predetermined or definable sequence of events. The pumped-out washing liquid is fed either to a heat exchanger of the dishwasher 1 (not shown in the drawings), to a wastewater connection of the dishwasher 1, or to a wastewater regeneration unit of the dishwasher 1.

[0106] The control device 50 of the tank cleaning system is particularly designed to control the tank cleaning system automatically and preferably optionally automatically in such a way that the cleaning fluid is sprayed into the wash tank 3 via the cleaning nozzles 20 of the tank cleaning system when at least part of the wash fluid contained in the wash tank 3 is pumped out or has been pumped out by means of the wastewater pump 25.

[0107] Alternatively or additionally, the control device 50 is designed to determine, depending on a sensor-detected degree of contamination of the washing liquid received in the washing tank 3, a time or a period of time when or during which the cleaning liquid is to be sprayed in the washing tank 3 by means of the cleaning nozzles 20 of the tank cleaning system.

[0108] The control device 50 can also be configured to determine, depending on the degree of contamination detected by the sensor in the washing tank 3, an amount of cleaning fluid to be sprayed per unit of time using the cleaning nozzles 20 of the tank cleaning system.

[0109] The contamination or degree of contamination of the washing liquid received in the washing tank 3 can be detected, for example, using a turbidity sensor.

[0110] Alternatively or additionally, the level of the washing liquid in the washing tank 3 can also be used to infer the degree of contamination of the washing liquid in the washing tank 3.

[0111] Although not explicitly shown in the drawings, the tank cleaning system preferably has a fluid supply that is fluidically connected or connectable to the cleaning nozzles 20 of the tank cleaning system, via which the cleaning fluid to be sprayed can be supplied to the cleaning nozzles 20 of the tank cleaning system as required.

[0112] The cleaning fluid is preferably fresh water, especially cold fresh water. Alternatively, heated water, especially heated fresh water, or regenerated washing fluid from washing tank 3 can also be used. Cleaning chemicals can also be added to the cleaning fluid as needed.

[0113] The cleaning nozzles 20 of the tank cleaning system are preferably designed as rotary nozzles and configured to produce a rotating spray jet.

[0114] In particular, the cleaning nozzle 20 has a housing 21 with a fluid inlet 22 and a rotor 23 rotatably mounted in or on the housing 21 with two outlet openings 24 that are at least partially opposite each other.

[0115] The invention is not limited to the embodiments shown in the drawings, but results from a combination of all the features disclosed herein. Bezugszeichenliste

[0116] 1 Dishwasher 2 Treatment chamber 3 Wash tank 4 Wash pump 5 Wash nozzle 6 Wash arm 7 Rinse arm 9 Rinse aid concentrate reservoir 10 Water heater / boiler 11 Fresh water connection of the water heater 12 Rinse pump 13 Rinse nozzle 14 Tank cover screen 15 Dirt collection area 16 Fine filter 17 Dirt discharge pipe system 18 Feed opening 19 Level sensor 20 Cleaning nozzle 25 Wastewater pump 50 Control unit 50 A. Upper level of the wash tank B. Floor area / lower level of the wash tank T. Depth of the wash tank

Claims

1. Dishwasher (1) with at least one washing system designed as a recirculation circuit, in particular a dishwasher or utensil washer, which is designed as a program-controlled dishwasher or as a conveyor dishwasher, wherein the at least one washing system comprises a nozzle system with at least one washing nozzle (5) for spraying washing liquid onto the items to be cleaned, a washing tank (3) for collecting at least one part of the sprayed washing liquid and a washing pump (4) for supplying washing liquid collected in the washing tank (3) to the at least one washing nozzle (5), characterized by the fact thatThe dishwasher (1) has a tank cleaning system associated with the wash tank (3) with at least one cleaning nozzle (20) arranged in or on the wash tank (3) such that, in particular as required and preferably at the end of a washing shift or a washing day of the dishwasher (1), a cleaning fluid can be sprayed into the wash tank (3) or injected into the wash tank (3) via the at least one cleaning nozzle (20) of the tank cleaning system for cleaning the wash tank (3) and / or components contained in the wash tank (3).

2. Dishwasher (1) according to claim 1, wherein the dishwasher (1) has a dirt collection system associated with the wash tank (3) with a tank cover screen (14), wherein the tank cover screen (14) is designed to separate dirt particles from the sprayed washing liquid which flows back into the wash tank (3) by gravity, wherein the at least one cleaning nozzle (20) of the tank cleaning system is arranged in the wash tank (3) below the tank cover screen (14).

3. Dishwasher (1) according to claim 2, wherein the at least one cleaning nozzle (20) of the tank cleaning system is arranged in the wash tank (3) and / or designed in such a way as to apply the cleaning fluid to the underside of the tank cover screen (14) at least partially, particularly as required and preferably at the end of a washing shift or washing day of the dishwasher (1).

4. Dishwasher (1) according to claim 2 or 3, wherein the dirt collection system has a dirt collection area (15) arranged at least partially or in sections in the wash tank (3) and open at the top for collecting the dirt particles separated from the washing liquid by means of the tank cover sieve (14), and wherein the at least one cleaning nozzle (20) of the tank cleaning system is arranged in the wash tank (3) and / or designed in such a way as to apply the cleaning liquid to the dirt collection area (15) at least in sections, particularly as required and preferably at the end of a wash cycle or wash day of the dishwasher (1).

5. Dishwasher (1) according to claim 4, wherein the dirt collection area (15) has a wall area permeable to washing liquid, in particular in the form of a sieve and preferably in the form of a fine sieve (16), and wherein the at least one cleaning nozzle (20) of the tank cleaning system is arranged in the wash tank (3) and / or is designed in such a way as to, in particular as required and preferably at the end of a wash cycle or a wash day of the dishwasher (1), at least partially supply the wall area of ​​the dirt collection area (15) permeable to washing liquid with the cleaning liquid; and / or wherein the dishwasher (1) further comprises a dirt discharge system flowing with the dirt collection area (15) and a dirt discharge pipe system (17) through which the dirt collection area (15) can be emptied as required;and / or wherein the tank cover screen (14) is arranged above the dirt collection area (15) and has a drainage slope towards a feed opening (18), wherein the upwardly open dirt collection area (15) is arranged below the feed opening (18) of the tank cover screen (14) such that the dirt particles separated from the washing liquid by means of the tank cover screen (14) enter the dirt collection area (15) via the feed opening (18), wherein preferably the tank cover screen (14) is funnel-shaped at least in some areas, and wherein the feed opening (18) is formed within the funnel-shaped area of ​​the tank cover screen (14) and preferably in a tapered area of ​​the funnel-shaped area of ​​the tank cover screen (14).

6. Dishwasher (1) according to one of claims 1 to 5, wherein at least one sensor (19) for level monitoring and / or at least one heating element are arranged at least partially or in certain areas in the wash tank (3), and wherein the at least one cleaning nozzle (20) of the tank cleaning system is arranged and / or designed in the wash tank (3) in such a way as to apply the cleaning fluid to the at least one sensor (19) and / or the at least one heating element at least in certain areas, particularly as required and preferably at the end of a wash cycle or wash day of the dishwasher (1).

7. Dishwasher (1) according to one of claims 1 to 6, wherein the at least one cleaning nozzle (20) of the tank cleaning system and preferably all cleaning nozzles (20) of the tank cleaning system are arranged and in particular integrated in at least one side wall region of the wash tank (3), wherein the wash tank (3) has a defined depth (T) between an upper level (A) in which an edge region of a tank cover screen (14) associated with the wash tank (3) is located, and a lower level (B) in which a bottom surface of the wash tank (3) forming the bottom of the wash tank (3) is located, and wherein preferably the at least one cleaning nozzle (20) and preferably all cleaning nozzles (20) of the tank cleaning system are arranged and in particular integrated in an upper side wall region of the wash tank (3),wherein preferably the at least one cleaning nozzle (20) and preferably all cleaning nozzles (20) of the tank cleaning system are arranged and in particular integrated in a side wall region of the wash tank (3) which - measured from the lower level (B) of the wash tank (3) - lies in a region between 55% and 85% of the depth (T) and in particular in a region between 60% and 75% of the depth (T).

8. Dishwasher (1) according to one of claims 1 to 7, wherein the at least one washing system is at least partially or partially accommodated in a treatment chamber (2) or in a treatment zone of the dishwasher (1), wherein the treatment chamber (2) or treatment zone of the dishwasher (1) has an access opening that can be closed, in particular manually, and wherein at least one cleaning nozzle (20) of the tank cleaning system is arranged in or on a side wall area of ​​the wash tank (3) which is opposite the access opening.

9. Dishwasher (1) according to one of claims 1 to 8, wherein the tank cleaning system has a control device (50), or wherein a control device (50) is assigned to the tank cleaning system, wherein the control device (50) is configured to control the tank cleaning system as required or according to a predetermined or definable sequence of events such that the cleaning fluid is sprayed into the wash tank (3) via the at least one cleaning nozzle (20) of the tank cleaning system or is sprayed into the wash tank (3).

10. Dishwasher (1) according to one of claims 1 to 9, wherein a wastewater pump (25) is associated with the wash tank (3) of the dishwasher (1), the suction side of which is flow-connected or connectable to the wash tank (3) in order to pump out at least a part of the washing liquid contained in the wash tank (3), in particular as required or in particular according to a predetermined or definable sequence of events, from the wash tank (3) and to supply the pumped out, at least a part of the washing liquid contained in the wash tank (3) to a heat exchanger of the dishwasher (1) or a wastewater connection of the dishwasher (1) or a wastewater regeneration device of the dishwasher (1).

11. Dishwasher (1) according to claims 9 and 10, wherein the control device (50) is configured to control the tank cleaning system, in particular automatically and preferably optionally automatically, such that the cleaning fluid is sprayed into the wash tank (3) via the at least one cleaning nozzle (20) of the tank cleaning system, or is sprayed into the wash tank (3) when at least part of the wash fluid received in the wash tank (3) is pumped out or has been pumped out by means of the wastewater pump (25).

12. Dishwasher (1) according to one of claims 1 to 11 and at least according to claim 9, wherein the dishwasher (1) has a sensor configured to detect the degree of contamination of the washing liquid contained in the wash tank (3), wherein the control device (50) is configured, depending on the detected degree of contamination of the washing liquid contained in the wash tank (3), to determine a time and / or a duration when, or during which, the cleaning liquid is to be sprayed, in particular as required, by means of the at least one cleaning nozzle (20) of the tank cleaning system, and / or to determine a quantity of cleaning liquid to be sprayed per unit of time by means of the at least one cleaning nozzle (20) of the tank cleaning system.

13. Dishwasher (1) according to one of claims 1 to 12 and in particular according to claim 12, wherein the wash tank (3) is assigned a sensor system which is designed to detect the degree of soiling of the wash liquid taken up in the wash tank (3) at least indirectly on the basis of a turbidity of the wash liquid taken up in the wash tank (3) and / or on the basis of a wash liquid level of the wash liquid taken up in the wash tank (3).

14. Dishwasher (1) according to one of claims 1 to 13, wherein the cleaning fluid to be sprayed as required by the at least one cleaning nozzle (20) of the tank cleaning system comprises fresh water, in particular cold fresh water, heated water, in particular heated fresh water, or regenerated washing fluid from the wash tank (3) and optionally a correspondingly dosed cleaning chemical;and / or wherein the tank cleaning system has a liquid supply which is or can be connected to the at least one cleaning nozzle (20) of the tank cleaning system, via which the cleaning liquid to be sprayed can be supplied to the at least one cleaning nozzle (20) of the tank cleaning system as required, wherein the liquid supply of the tank cleaning system preferably has at least one valve which can be controlled via a control device (50) of the dishwasher (1) and / or at least one cleaning liquid pump which can be controlled via a control device (50) of the dishwasher (1), via which or via which a quantity of cleaning liquid to be supplied or supplied per unit of time to the at least one cleaning nozzle (20) of the tank cleaning system can be adjusted.

15. Dishwasher (1) according to one of claims 1 to 14, wherein the at least one cleaning nozzle (20) of the tank cleaning system is designed and configured as a rotary nozzle to produce a rotating spray jet, wherein the at least one cleaning nozzle (20) preferably has a housing (21) with a fluid inlet (22) and a rotor (23) rotatably mounted in or on the housing (21) with two outlet openings (24) that are at least partially opposite each other.

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