Method for operating a commercial dishwasher and dishwasher

Abstract

The invention relates to a method for operating a commercial dishwasher (1), wherein, during a washing phase, a washing liquid is sprayed in a treatment chamber (2) of the dishwasher (1), particularly in a recirculating manner, and wherein, during a rinsing phase following the washing phase, a rinsing liquid is sprayed in the treatment chamber (2) of the dishwasher (1). According to the invention, the rinsing phase is divided into a first rinsing phase and at least a second rinsing phase, wherein the rinsing liquid is sprayed at different, in particular different, average rinsing liquid temperatures in the rinsing phases. The invention further relates to a corresponding dishwasher (1).

Description

[0001] The present invention relates generally to the field of commercial dishwashing.

[0002] In particular, the invention relates to a method for operating a commercial dishwasher, which is designed in particular as a program machine or as a hood-type dishwasher, and to a corresponding dishwasher.

[0003] The dishwasher according to the invention is designed, in particular, as a programmable automatic dishwasher or as a conveyor dishwasher and comprises a container for temporarily storing liquids. The container has a liquid inlet that can be fluidly connected to a fresh water source as needed, and a liquid outlet that can be fluidly connected to a consumer, in particular a consumer of the dishwasher, as needed. According to embodiments of the dishwasher according to the invention, the container for temporarily storing liquids is, in particular, a fresh water tank and / or a fresh water booster.

[0004] Programmable dishwashers are manually loaded and unloaded dishwashers. These can be pass-through dishwashers, also known as hood-type dishwashers, or front-loaders. Front-loaders can be undercounter, countertop, or freestanding dishwashers with front loading.

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

[0006] A dishwasher designed as a programmable automatic dishwasher also features a wash system with a wash pump, a piping system connected to the wash pump, and wash nozzles. The wash liquid in the wash tank can be pumped from the wash pump via the piping system to the wash nozzles and sprayed onto the items to be cleaned through the wash nozzles in the treatment chamber. The sprayed wash liquid then flows back into the wash tank.

[0007] Accordingly, commercial dishwashers designed as programmable or hood-type dishwashers are characterized by the fact that, for treating (cleaning) the wash items in the treatment chamber, a wash liquid is sprayed, particularly in a recirculating manner, within the treatment chamber during a wash phase. In the subsequent final rinse phase, a final rinse liquid is sprayed within the treatment chamber. The wash liquid sprayed within the treatment chamber during the wash phase flows back by gravity into a wash tank, usually located below the treatment chamber.

[0008] The temperature of the washing liquid is typically approximately 60°C. Only the energy that is removed from the overall system during the cleaning process needs to be reintroduced into the washing liquid, for example, through energy input into the washware and / or through evaporation losses or heat dissipation into the environment.

[0009] In contrast to the recirculated wash liquid, the rinse phase following the wash phase uses rinse liquid, which is usually fresh water to which a rinse-aid chemical may be added. Before being sprayed onto the dishes to be rinsed via appropriate rinse-aid nozzles in the dishwasher's treatment chamber, the rinse liquid is heated to approximately 80°C using a rinse-aid heater (boiler).

[0010] After the final rinse, the rinse aid liquid also flows into the wash tank of the dishwasher, which on the one hand regenerates the wash liquid and on the other hand introduces a certain amount of energy into the wash liquor, since the temperature of the rinse aid liquid is usually higher than that of the wash liquid (wash liquor) that is sprayed into the treatment chamber of the dishwasher during the wash phase.

[0011] Based on the process steps described above, it is clear that when considering the total energy consumption of such a dishwasher, a large proportion of the energy is required to heat the fresh water or the rinse aid liquid for the rinse phase.

[0012] The present invention is based on the object of specifying a method for operating a commercial dishwasher which is designed as a program machine or as a hood-type dishwasher, whereby with the aid of this method the energy consumption of the dishwasher during operation can be reduced without reducing the cleaning efficiency and in particular the final rinse efficiency of the dishwasher.

[0013] Furthermore, according to the task, a corresponding dishwasher, in particular a commercial dishwasher in the form of a program machine or in the form of a hood dishwasher, which can save energy during operation is to be specified.

[0014] With regard to the method, the object underlying the invention is achieved by the subject matter of independent patent claim 1, wherein advantageous developments of the operating method according to the invention are specified in dependent patent claims 1 to 13.

[0015] With regard to the dishwasher, the object underlying the invention is achieved by the subject matter of the independent patent claim 14, wherein an advantageous development of the dishwasher according to the invention is specified in the dependent patent claim 15.

[0016] Accordingly, the invention relates in particular to a method for operating a commercial dishwasher which is designed as a programmer or as a hood-type dishwasher, wherein in the method a washing liquid is sprayed in a treatment chamber of the dishwasher during a washing phase, in particular in a recirculating manner, and wherein a rinsing liquid is sprayed in the treatment chamber of the dishwasher during a final rinsing phase following the washing phase.

[0017] The method according to the invention is characterized in particular in that the final rinse phase is divided into a first final rinse phase and into at least one second final rinse phase, wherein in the final rinse phases the final rinse liquid is sprayed at different, in particular different average, final rinse liquid temperatures.

[0018] In particular, the method according to the invention provides that the rinse aid liquid sprayed in the final rinse phase in the treatment chamber of the dishwasher has a first, in particular average, minimum temperature during the first final rinse phase, which is higher than a particularly average temperature of the washing liquid sprayed in the treatment chamber of the dishwasher during the washing phase.

[0019] Additionally or alternatively, it is provided in particular that the rinse aid liquid sprayed in the final rinse phase in the treatment chamber of the dishwasher has a second, in particular average, temperature during the second final rinse phase, which is lower than the in particular average (first) temperature of the rinse aid liquid sprayed in the treatment chamber of the dishwasher during the first final rinse phase.

[0020] The present invention is based on the finding that, when considering the total energy consumption of a dishwasher of the type considered here, a large proportion is usually required for heating the fresh water or for heating the rinse aid liquid for the final rinse phase. With regard to optimizing the energy consumption of such a dishwasher, it follows that the greatest savings potential lies in reducing the amount of fresh water or rinse aid liquid, so that less fresh water or rinse aid liquid simply needs to be heated. On the other hand, however, the amount of fresh water or rinse aid liquid used for final rinsing during a final rinse phase cannot be reduced arbitrarily, since, for hygiene reasons, a perfect final rinse result must always be guaranteed.

[0021] Due to this dilemma, the inventive approach outlined above still makes it possible to further reduce the energy consumption of the dishwasher during its operation.

[0022] In detail, a reduction in energy consumption can be achieved by dividing the second process step in the treatment of wash ware, namely the final rinse phase, into at least two sub-steps, so that only a part of the total amount of fresh water or final rinse liquid required for a perfect final rinse result is heated to the aforementioned approximately 80°C, whereas the second part of the fresh water final rinse or final rinse is carried out at a reduced temperature which, from an energy point of view, is as close as possible to the desired washing temperature of, for example, approximately 60°C.

[0023] In this context, it is advisable to include a draining phase in the final rinse phase between the first final rinse phase and the second final rinse phase, during which no final rinse liquid is sprayed into the dishwasher's treatment chamber. This additional draining phase / drip time allows a large portion of the wash liquor / wash liquid applied to the washware during the wash phase to be rinsed off and neutralized during the first final rinse sub-process step, i.e., the first final rinse phase, before the final rinse is performed in the second final rinse sub-process step, i.e., the second final rinse phase.Depending on the items to be washed, this additional pause for the final rinse during the draining phase between the first and second final rinse phases has the potential to reduce the total amount of fresh water required per cleaning cycle during the final rinse phase compared to current processes while maintaining the same final rinse result.

[0024] As an alternative to a draining phase between the first and second rinse phases, it is also conceivable for the first rinse phase to overlap, at least temporarily, with the second rinse phase. In this case, no draining phase is provided, and rinse aid liquid is continuously sprayed into the dishwasher's treatment chamber during the rinse phase, initially at a first temperature (during the first rinse phase) and subsequently at a second temperature (during the second rinse phase). These two rinse phases seamlessly transition into one another with regard to the temperature of the rinse aid liquid.

[0025] In particular, it is advisable for the rinse aid liquid sprayed in the final rinse phase in the treatment chamber of the dishwasher to have a particularly average temperature during the second final rinse phase which is equal to or higher than a particularly predetermined or definable minimum temperature of the washing liquid sprayed or to be sprayed in the treatment chamber of the dishwasher during the washing phase.

[0026] Alternatively or additionally, according to embodiments of the invention, the rinse aid liquid sprayed in the final rinse phase in the treatment chamber of the dishwasher has a particularly average temperature of 55°C to 90°C, preferably a particularly average temperature of 65°C to 90°C, more preferably a particularly average temperature of 75°C to 90°C and most preferably a particularly average temperature of 80°C to 85°C during the first final rinse phase.

[0027] On the other hand, according to embodiments of the invention, it is provided that the rinse aid liquid sprayed in the final rinse phase in the treatment chamber of the dishwasher has a particularly average temperature of 50°C to 80°C, preferably a particularly average temperature of 55°C to 75°C, and even more preferably a particularly average temperature of 55°C to 65°C during the second final rinse phase.

[0028] With regard to the washing liquid sprayed or to be sprayed in the treatment chamber of the dishwasher during the washing phase, it is particularly provided that this is heated compared to the ambient temperature of the dishwasher, in particular to a predetermined or definable minimum temperature of 50°C, preferably 55°C and more preferably 60°C.

[0029] In the method according to the invention, it is provided in particular that after the washing phase and preferably between the washing phase and the final rinsing phase, a particularly predetermined or definable amount of washing liquid is removed and in particular pumped out from a washing tank of the dishwasher.

[0030] The removed and in particular pumped-out washing liquid can be fed to a heat exchanger system in order to "recover" at least part of the kinetic energy of the removed / pumped-out washing liquid and to use this recovered kinetic energy to heat the rinse liquid to be sprayed in the rinse phase as needed.

[0031] In particular, the quantity of washing liquid to be discharged from the washing tank of the dishwasher after the washing phase corresponds at least substantially to the quantity of rinse aid liquid that is sprayed in the treatment chamber of the dishwasher in the rinse aid phase.

[0032] In this context, it is particularly appropriate that during the final rinse phase and in particular after the end of the first final rinse phase, a temperature of the wash liquid regenerated with the rinse liquid already sprayed in the final rinse phase is determined and, in particular, measured. In this context, it is conceivable that a temperature of the rinse liquid to be sprayed and, in particular, still to be sprayed during the second final rinse phase is selected and, in particular, adjusted (preferably, adjusted in a controlled manner) in such a way that, at the latest at the end of the final rinse phase of a cleaning cycle, the temperature of the wash liquid regenerated with the rinse liquid corresponds to a predetermined or definable wash liquid temperature of, for example, 60°C.

[0033] The predefined or definable washing liquid temperature depends in particular on a cleaning program and, furthermore, in particular on the type of items to be accommodated and treated in the treatment chamber of the dishwasher during the cleaning cycle. As already explained, the predefined or definable washing liquid temperature can also be lower than 60°C, for example, 50°C or 55°C.

[0034] According to implementations of the present invention, a total amount of rinse aid liquid, in particular a predetermined or definable amount, is sprayed into the treatment chamber of the dishwasher during the final rinse phase. This predetermined or definable amount of rinse aid liquid sprayed or to be sprayed into the treatment chamber of the dishwasher during the final rinse phase is approximately 1.5 to 2.5 liters, and preferably approximately 2.0 liters, depending on the selected treatment program. Of course, other rinse aid volumes are also conceivable.

[0035] According to developments of the invention, the total amount of rinse aid liquid to be sprayed in the treatment chamber of the dishwasher during the final rinse phase is divided into a first partial amount and a second partial amount. The first partial amount is the proportion of the total amount of rinse aid liquid to be sprayed in the treatment chamber of the dishwasher during the final rinse phase that is to be sprayed or is sprayed in the treatment chamber of the dishwasher during the first final rinse phase. The second partial amount is the proportion of the total amount of rinse aid liquid to be sprayed in the treatment chamber of the dishwasher during the final rinse phase that is to be sprayed or is sprayed in the treatment chamber of the dishwasher during the second final rinse phase.

[0036] Depending on the type of items to be processed and, in particular, cleaned in the treatment chamber, the first and second partial quantities of rinse aid liquid to be sprayed in the corresponding rinse phase can be adjusted. In particular, the first partial quantity of rinse aid liquid to be sprayed or atomized in the first rinse phase is different from the second partial quantity of rinse aid liquid to be sprayed or atomized in the second rinse phase.

[0037] In particular, according to embodiment variants of the invention, it is provided that the first partial quantity of the final rinse liquid to be sprayed or sprayed in the first final rinse phase or the second partial quantity of the final rinse liquid to be sprayed or sprayed in the second final rinse phase is adjustable and in particular variably adjustable, in particular depending on a selected washing program for the dishwasher and / or depending on a type of washware treated or to be treated in the treatment chamber of the dishwasher.

[0038] According to a conceivable implementation of the last-mentioned aspect, it is provided that the first partial quantity of the rinse aid liquid to be sprayed or sprayed in the first rinse phase corresponds to 50% of the total quantity of rinse aid liquid to be sprayed during the rinse phase and the second partial quantity of the rinse aid liquid to be sprayed or sprayed in the second rinse phase corresponds to 50% of the total quantity of rinse aid liquid to be sprayed during the rinse phase if the following type of washware is or is to be treated in the treatment chamber: plates, bowls and / or small dishes made of porcelain or a porcelain-like material.

[0039] Alternatively or additionally, it is conceivable that the first partial quantity of the rinse aid liquid to be sprayed or sprayed in the first final rinse phase corresponds to 20% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase and the second partial quantity of the rinse aid liquid to be sprayed or sprayed in the second final rinse phase corresponds to 80% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase if the following type of washware is or is to be treated in the treatment chamber: glasses, in particular drinking glasses or other washware items made of glass or a glass-like material.

[0040] Furthermore, alternatively or additionally to this, it is conceivable that the first partial quantity of the rinse aid liquid to be sprayed or sprayed in the first rinse phase corresponds to 70% of the total quantity of rinse aid liquid to be sprayed during the rinse phase and the second partial quantity of the rinse aid liquid to be sprayed or sprayed in the second rinse phase corresponds to 30% of the total quantity of rinse aid liquid to be sprayed during the rinse phase if the following type of washware is or is to be treated in the treatment chamber: utensils, cutlery, pots and / or pans.

[0041] The object underlying the invention is further achieved by the subject matter of the independent patent claim 14, which relates to a dishwasher, in particular a commercial dishwasher in the form of a programmable automatic dishwasher or in the form of a hood-type dishwasher. The dishwasher according to the invention has a treatment chamber for receiving dishes to be cleaned, a washing system with at least one washing pump and washing nozzles, via which washing liquid can be sprayed in a recirculating manner in the treatment chamber during a washing phase of a cleaning cycle, a washing tank provided below the treatment chamber, in which at least part of the washing liquid sprayed in the treatment chamber via the washing nozzles of the washing system can be received, and a final rinse system with at least one final rinse pump and final rinse nozzles, via which final rinse liquid in the form of fresh water with, if appropriate,added rinse aid can be sprayed into the treatment chamber.

[0042] In the dishwasher according to the invention, it is provided that the rinse aid system has a rinse aid liquid heater (boiler) via which, in particular selectively and / or as required, the rinse aid liquid to be sprayed in the treatment chamber of the dishwasher during the rinse aid phase or the fresh water of the rinse aid liquid to be sprayed in the treatment chamber of the dishwasher during the rinse aid phase can be heated to a predetermined or definable temperature, in particular a minimum temperature.

[0043] The dishwasher according to the invention is characterized in particular in that the final rinse system is designed to spray the final rinse liquid at a first, in particular average, final rinse liquid temperature in a first final rinse phase of the final rinse phase and to spray the final rinse liquid at a second, in particular average, final rinse liquid temperature that is different from the first, in particular average, final rinse liquid temperature in a second final rinse phase of the final rinse phase.

[0044] In particular, the dishwasher according to the invention is provided with a control device which is designed to control the final rinse system of the dishwasher for carrying out the aforementioned method according to the invention.

[0045] An exemplary embodiment of the present invention will be described in more detail below with reference to the accompanying drawings.

[0046] It shows: FIG. 1 schematically shows a hydraulic diagram of an exemplary embodiment of the dishwasher according to the invention, which is designed in the form of a programmable automatic machine.

[0047] In FIG. 1 is a hydraulic diagram of an exemplary embodiment of the dishwasher 1 according to the invention. It should be noted that - although the exemplary embodiment of the dishwasher 1 according to the invention FIG. 1 is designed in the form of a programmable automatic machine - the invention is not limited to dishwashers in the form of a programmable automatic machine.

[0048] In particular, the invention also relates to hood-type dishwashers and corresponding methods for operating such dishwashers.

[0049] It is also conceivable that the invention will be implemented in dishwashers designed as conveyor dishwashers.

[0050] The exemplary embodiment of the dishwasher 1 designed as a program machine according to FIG. 1 has a program control device 18 for controlling at least one cleaning program and a through a door (in FIG. 1 not shown) or a hood (also in FIG. 1 not shown) closable treatment chamber 2 in a machine housing for receiving items to be cleaned (in FIG. 1 not shown) such as dishes, cutlery, pots, pans, trays and cooking utensils.

[0051] Below the treatment chamber 2 there is a washing tank 3 for collecting sprayed liquid from the treatment chamber 2.

[0052] A wash pump 4 is provided for conveying wash liquid from the wash tank 3 through a wash liquid line system 5 to wash nozzles 6, which are directed toward the area of ​​the washware to be cleaned in the treatment chamber 2 and spray the wash liquid onto the washware, particularly during a wash phase. The sprayed wash liquid falls back into the wash tank 3 by gravity. Thus, the wash tank 3, the wash pump 4, the wash liquid line system 5, the wash nozzles 6, together with the treatment chamber 2, form a wash liquid circuit. The wash liquid line system 5 connects the pressure side of the wash pump 4 to the corresponding wash nozzles 6.

[0053] Furthermore, a rinse system is provided for pumping rinse liquid by means of a rinse pump 7 through a rinse liquid line system 8 to rinse nozzles 9, which are directed in the treatment chamber 2 toward the area of ​​the items to be cleaned. The rinse liquid sprayed during a rinse phase falls by gravity from the treatment chamber 2 into the wash tank 3. The rinse liquid line system 8 connects the pressure side of the rinse pump 7 to the rinse nozzles 9.

[0054] Preferably, a plurality of washing nozzles 6 are provided on at least one upper washing arm, a plurality of washing nozzles 6 on at least one lower washing arm, a plurality of rinsing nozzles 9 on at least one upper rinsing arm and a plurality of rinsing nozzles 9 on at least one lower rinsing arm.

[0055] Before rinse aid liquid is sprayed during a rinse phase in a cleaning cycle of the dishwasher 1, a quantity of washing liquid corresponding to the rinse aid liquid is pumped out of the washing tank 3 by means of a drain pump 10, the suction side of which is connected to a sump of the washing tank 3 via a drain line.

[0056] If the wash tank 3 is empty before the first start of the dishwasher 1, which is designed, for example, as a programmable automatic dishwasher, it must first be filled with fresh water via a fresh water line 12 or by means of the rinse aid system and its rinse aid pump 7 with fresh water or another rinse aid liquid or washing liquid. The rinse aid liquid can be fresh water or fresh water mixed with rinse aid. The washing liquid contains detergent, which is added to the liquid contained in the wash tank 3 by a detergent dosing device (in FIG. 1not shown) is preferably added automatically.

[0057] The program control device 18 controls the wash pump 4, the rinse pump 7, the drain pump 10 and a detergent solution pump (in FIG. 1 (not shown) depending on the cleaning program selected by an operator on the program control device 18. At least one cleaning program is provided; preferably, several optionally selectable cleaning programs are provided.

[0058] At the FIG. 1In the schematically illustrated exemplary embodiment of the dishwasher 1 according to the invention, the rinse aid pump 7 is connected on the suction side to a boiler (rinse aid liquid heater 11). The boiler 11 further has an inlet connected to a fresh water supply line 14, through which either fresh water or fresh water with added rinse aid is supplied to the boiler 11. In the boiler 11, the liquid supplied via the inlet (pure fresh water or fresh water with added rinse aid) is heated according to a specified process sequence.

[0059] The rinse aid pump 7, whose suction side is connected to the boiler outlet, can supply the rinse aid liquid heated in the boiler 11, for example, during a fresh water rinse phase, via the rinse aid line system 8 to the rinse aid nozzles 9. The rinse aid nozzles 9 are arranged in the treatment chamber 2 of the dishwasher 1 in order to spray the rinse aid liquid heated by the boiler 11 onto the dishes in the treatment chamber 2.

[0060] Of course, it is also conceivable that pure fresh water is supplied to the boiler 11 via the inlet and the fresh water supply line 14, to which rinse aid is added after heating in the boiler 11.

[0061] Although in FIG. 1Not shown, the exemplary embodiment of the dishwasher 1 according to the invention can also be assigned a fresh water tank without heating in addition to or as an alternative to the boiler 11. This fresh water tank preferably has an inlet connected to a fresh water supply line, via which pure fresh water or fresh water with added rinse aid is supplied to the fresh water tank.

[0062] Of course, it is also conceivable to arrange a dosing device for adding rinse aid downstream of the outlet of the fresh water tank.

[0063] At the FIG. 1In the schematically illustrated embodiment of the dishwasher 1 according to the invention, the boiler 11 is connected to a backflow preventer 13 via at least one fresh water supply line 14. The backflow preventer 13 serves to prevent fresh water from being sucked back into a fresh water supply line 12 from the suction side of the rinse pump 7.

[0064] The water flow within the FIG. 1The schematically illustrated dishwasher 1 is as follows: the fresh water enters the boiler 11 via a filling valve 15 and the backflow preventer 13. If necessary, the fresh water is heated there by the heater 16. The liquid fill level in the boiler 11 can be detected by a pressure sensor 17. The fresh water, possibly heated in the boiler 11, is pumped into the treatment chamber 2 of the dishwasher 1 via the rinse pump 7 and the rinse nozzles 9. The fresh water sprayed in the treatment chamber 2 collects in the wash tank 3. A heater 16 is preferably provided in the wash tank 3 in order to keep the liquid collected in the wash tank 3 at the right temperature. The liquid fill level of the wash tank 3 can be detected by a pressure sensor 17. After a washing phase, part of the liquid collected in the washing tank 3 (washing liquid) is pumped out of the dishwasher 1 into a drain by the drain pump 10.This pumped-out washing liquid is replaced by fresh water or liquid from boiler 11.

[0065] The dishwasher 1 according to the invention, as shown schematically in an exemplary embodiment in FIG. 1is shown, is characterized in particular in that in a cleaning cycle of the dishwasher 1, the final rinse phase, during which final rinse liquid is sprayed in the treatment chamber 2 of the dishwasher 1 onto the dishes held there, is divided into a first final rinse sub-phase and a second final rinse sub-phase. In the first final rinse sub-phase of the final rinse phase, the final rinse liquid or the fresh water is sprayed onto the dishes at a first, in particular average, final rinse liquid temperature, while in the second final rinse sub-phase of the final rinse phase, the final rinse liquid is sprayed onto the dishes in the treatment chamber 2 of the dishwasher 1 at a second, in particular average, final rinse liquid temperature that is different from the first, in particular average, final rinse liquid temperature.The rinse aid liquid sprayed in the treatment chamber 2 of the dishwasher 1 has a first, in particular average, temperature during the first rinse phase, which is higher than a particularly average temperature of the washing liquid sprayed in the treatment chamber 2 of the dishwasher 1 during the washing phase.

[0066] On the other hand, the rinse aid liquid sprayed in the treatment chamber 2 of the dishwasher 1 during the final rinse phase has a second, in particular average, temperature during the second final rinse phase, which is lower than the in particular average temperature of the rinse aid liquid sprayed in the treatment chamber 2 of the dishwasher 1 during the first final rinse phase.

[0067] The invention is not limited to the FIG. 1shown exemplary embodiment of the dishwasher 1 according to the invention, but results from a synopsis of all features disclosed herein.

[0068] In particular, the inventive concept can be seen in the fact that the final rinsing process step, and in particular the fresh water final rinsing, is divided into at least two sub-process steps. In the first sub-process step, the fresh water final rinsing takes place, as has been customary up to now, at a temperature of approximately 80°C, by heating the required fresh water to this temperature in advance in the boiler 11. The amount of fresh water used for this first sub-process step is, for example, 50% of the total fresh water quantity required for a perfect final rinsing result. Of course, the amount of fresh water used for the first sub-process step can also represent a larger or smaller proportion of the total amount.

[0069] The second sub-process step is then carried out at a reduced temperature, equal to the scrubbing liquid temperature. This means that this portion of the fresh water no longer needs to be heated to, for example, 80°C in boiler 11, but only to a lower temperature, typically approximately 60°C.

[0070] However, reducing the fresh water temperature to below 60°C for this second sub-process step would not make sense from an energy point of view, since the energy saved would then have to be used again in the wash tank 3 by means of the heating provided there, if any, in order to keep the washing liquid temperature constant at the pre-determined or determinable value of, for example, 60°C and to avoid a drop in the washing liquid temperature due to the supply of colder fresh water or colder rinse liquid.

[0071] A practical implementation of this two-part rinse-liquid or fresh water rinse can be achieved, for example, as follows: The first sub-process step, i.e., the first rinse phase, is essentially identical to the previously known rinse. In other words, the fresh water used for the rinse is heated in the boiler 11 to, for example, 80°C and then, after the wash phase has been completed, sprayed onto the items to be cleaned and rinsed via the rinse nozzles 9.

[0072] The difference, however, is that with the approach according to the invention, the amount of rinse aid liquid used in the first sub-process step is lower than the total amount of liquid required for the rinse phase in the conventional approach. For example, during the first rinse phase, only 1 liter (50%) is sprayed into the treatment chamber 2 of the dishwasher 1 instead of the usual 2 liters.

[0073] After the first final rinse phase has been completed, or alternatively while the first final rinse phase is still running, the second final rinse phase begins. Here, the boiler 11 is refilled with cold fresh water, for example with 1 liter, so that the boiler 11 again has the same fill level as at the beginning of the first sub-process step, i.e. at the beginning of the first final rinse phase. However, this time the heating up to 80°C does not take place first as has previously been the case, but in combination with any fresh water remaining in the boiler 11 that has already been heated to 80°C, a mixed temperature of approx. 60°C is established in the boiler 11. This fresh water with a mixed temperature of approx. 60°C is then used directly for the second final rinse phase, i.e. for the second sub-process step of the final rinse phase. In other words, the second final rinse phase takes place with, for example, 1 liter of fresh water, which, however, only has a temperature of approx. 60°C instead of 80°C.Thus, the total rinse aid quantity remains, for example, 2 liters per cleaning cycle, meaning a perfect rinse result can still be guaranteed. However, of the two liters, only 1 liter (50%) needs to be heated to the final rinse temperature of 80°C, which allows for significant energy savings while maintaining the same rinse result.

[0074] A further aspect of this process sequence according to the invention is the possibility of providing a dripping pause between the first final rinse phase and the second final rinse phase. During this dripping pause, the fresh water or rinse aid liquid that was sprayed onto the dishes in the first final rinse phase can neutralize the wash liquor to be rinsed off and run off / drip off the dishes. This additional dripping time means that a large portion of the wash liquor (wash liquid) can be rinsed off and neutralized from the dishes in the first final rinse phase, before the final rinse takes place in the second final rinse phase. Depending on the dishes to be washed (type of dishes), this additional rinse pause has the potential to reduce the total amount of rinse aid liquid per cleaning cycle compared to the current standard process while maintaining the same rinse result. List of reference symbols

[0075] 1 Dishwasher 2 Treatment chamber 3 Wash tank 4 Wash pump 5 Wash liquid line system 6 Wash nozzle 7 Rinse pump 8 Rinse liquid line system 9 Rinse nozzle 10 Drain pump 11 Boiler / Rinse liquid heater 12 Fresh water supply line 13 Backflow preventer 14 Fresh water supply line 15 Fill valve 16 Heater 17 Pressure sensor 18 Program control device / Control device

Claims

1. A method for operating a commercial dishwasher (1), which is designed in particular as a programmer or as a hood-type dishwasher, wherein the method comprises the following method steps for each cleaning cycle: (i) during a washing phase, a washing liquid is sprayed in a treatment chamber (2) of the dishwasher (1), in particular in a recirculating manner; (ii) during a final rinsing phase following the washing phase, a final rinsing liquid is sprayed in the treatment chamber (2) of the dishwasher (1), characterized in that the final rinse phase in process step (ii) is divided into a first final rinse phase and into at least one second final rinse phase, wherein in the final rinse phases the final rinse liquid is sprayed at different, in particular different average, final rinse liquid temperatures.

2. Method according to claim 1, wherein the final rinse liquid sprayed in the treatment chamber (2) of the dishwasher (1) in method step (ii) has a first, in particular average, temperature during the first final rinse phase which is higher than a particularly average temperature of the washing liquid sprayed in the treatment chamber (2) of the dishwasher (1) in method step (i).

3. Method according to claim 1 or 2, wherein the final-rinse liquid sprayed in the treatment chamber (2) of the dishwasher (1) in method step (ii) has a second, in particular average, temperature during the second final-rinse phase which is lower than the in particular average temperature of the final-rinse liquid sprayed in the treatment chamber (2) of the dishwasher (1) during the first final-rinse phase.

4. Method according to one of claims 1 to 3, wherein in method step (ii) a dripping phase is provided between the first final rinse phase and the second final rinse phase, during which dripping phase no final rinse liquid is sprayed into the treatment chamber (2) of the dishwasher (1); or wherein in method step (ii) the first final rinse phase overlaps at least temporarily with the second final rinse phase.

5. Method according to one of claims 1 to 4, wherein the final rinse liquid sprayed in the treatment chamber (2) of the dishwasher (1) in method step (ii) has, during the second final rinse phase, a particularly average temperature which is equal to or higher than a particularly predetermined or definable minimum temperature of the washing liquid sprayed or to be sprayed in the treatment chamber (2) of the dishwasher (1) in method step (i).

6. The method according to any one of claims 1 to 5, wherein the final rinse liquid sprayed in the treatment chamber (2) of the dishwasher (1) in method step (ii) has, during the first final rinse phase, a particularly average temperature of 55°C to 90°C, preferably a particularly average temperature of 65°C to 90°C, more preferably a particularly average temperature of 75°C to 90°C, and most preferably a particularly average temperature of 80°C to 85°C; and / or wherein the final rinse liquid sprayed in the treatment chamber (2) of the dishwasher (1) in method step (ii) has, during the second final rinse phase, a particularly average temperature of 50°C to 80°C, preferably a particularly average temperature of 55°C to 75°C, and more preferably a particularly average temperature of 55°C to 65°C.

7. Method according to one of claims 1 to 6, wherein after method step (i) and preferably between method steps (i) and (ii) a particularly predetermined or definable amount of washing liquid is removed and in particular pumped out from a wash tank of the dishwasher (1), wherein the amount of washing liquid to be removed and in particular pumped out corresponds in particular at least substantially to the amount of final rinse liquid which is sprayed in total in the treatment chamber (2) of the dishwasher (1) in method step (ii) during the final rinse phase.

8. Method according to claim 7, wherein during the final rinse phase and in particular after the end of the first final rinse phase, a temperature of the washing liquid regenerated with the final rinse liquid already sprayed in method step (ii) is determined and in particular measured, wherein a temperature of the final rinse liquid to be sprayed and in particular still to be sprayed during the second final rinse phase is selected and in particular set such that at the latest at the end of the final rinse phase, the temperature of the washing liquid regenerated with the final rinse liquid corresponds to a pre-determined or determinable washing liquid temperature.

9. Method according to one of claims 1 to 8, wherein in method step (ii) during the final rinse phase in the treatment chamber (2) of the dishwasher (1) a total of in particular a predetermined or definable amount of final rinse liquid is sprayed, wherein the predetermined or definable amount of the final rinse liquid sprayed in method step (ii) during the final rinse phase in the treatment chamber (2) of the dishwasher (1) corresponds in particular to approximately 1.0 to 2.5 liters and preferably approximately 1.5 liters.

10. The method according to one of claims 1 to 9 and in particular according to claim 9, wherein the total amount of rinse aid liquid to be sprayed during the final rinse phase in the treatment chamber (2) of the dishwasher (1) is divided: - into a first partial amount which is to be sprayed or is sprayed in method step (ii) in the treatment chamber (2) of the dishwasher (1) during the first final rinse phase in the treatment chamber (2) of the dishwasher (1); and - into a second partial amount which is to be sprayed or is sprayed in method step (ii) in the treatment chamber (2) of the dishwasher (1) during the second final rinse phase in the treatment chamber (2) of the dishwasher (1).

11. The method according to claim 10, wherein the first partial amount of the rinse liquid to be sprayed or sprayed in the first rinse phase in method step (ii) is different from the second partial amount of the rinse liquid to be sprayed or sprayed in the second rinse phase in method step (ii).

12. Method according to claim 10 or 11, wherein the first partial quantity of the final rinse liquid to be sprayed or sprayed in the first final rinse phase in method step (ii) or the second partial quantity of the final rinse liquid to be sprayed or sprayed in the second final rinse phase in method step (ii) is adjustable and in particular variably adjustable, in particular depending on a selected washing program for the dishwasher (1) and / or depending on a type of washware treated or to be treated in the treatment chamber (2) of the dishwasher (1).

13. The method according to claim 12, wherein the first partial quantity of the rinse aid liquid to be sprayed or sprayed in the first final rinse phase in method step (ii) corresponds to 50% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase in method step (ii) and the second partial quantity of the rinse aid liquid to be sprayed or sprayed in the second final rinse phase in method step (ii) corresponds to 50% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase in method step (ii), if the following type of washware is or is to be treated in the treatment chamber (2): plates, bowls and / or small dishes made of porcelain or a porcelain-like material;and / or wherein the first partial quantity of the rinse aid liquid to be sprayed or sprayed in the first final rinse phase in process step (ii) corresponds to 20-40% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase in process step (ii) and the second partial quantity of the rinse aid liquid to be sprayed or sprayed in the second final rinse phase in process step (ii) corresponds to 60-80% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase in process step (ii), if the following type of washware is or is to be treated in the treatment chamber (2): glasses;and / or wherein the first partial quantity of the rinse aid liquid to be sprayed or sprayed in the first final rinse phase in process step (ii) corresponds to 60-80% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase in process step (ii) and the second partial quantity of the rinse aid liquid to be sprayed or sprayed in the second final rinse phase in process step (ii) corresponds to 20-40% of the total quantity of rinse aid liquid to be sprayed during the final rinse phase in process step (ii), if the following type of washware is or is to be treated in the treatment chamber (2): utensils, cutlery, pots and / or pans.; 14. Dishwasher (1), in particular commercial dishwasher (1) in the form of a programmer or in the form of a hood-type dishwasher, the dishwasher (1) comprising the following: - a treatment chamber (2) for receiving dishes to be cleaned; - a washing system with at least one washing pump (4) and washing nozzles (6), via which washing liquid can be sprayed in a recirculating manner in the treatment chamber (2) during a washing phase; - a washing tank (3) provided below the treatment chamber (2), in which at least part of the washing liquid sprayed via the washing nozzles (6) in the treatment chamber (2) can be received; and - a final rinse system with at least one final rinse pump (7) and final rinse nozzles (9), via which final rinse liquid in the form of fresh water with, if appropriate,added rinse aid can be sprayed in the treatment chamber (2), wherein the rinse aid system has a rinse aid liquid heater (11) via which the rinse aid liquid to be sprayed during the rinse aid phase in the treatment chamber (2) of the dishwasher (1) or the fresh water of the rinse aid liquid to be sprayed during the rinse aid phase in the treatment chamber (2) of the dishwasher (1) can be heated to a predetermined or definable temperature, in particular a minimum temperature, in particular selectively and / or as required. characterized in thatthe final-rinse system is designed to spray the final-rinse liquid at a first, in particular average, final-rinse liquid temperature in a first final-rinse sub-phase of the final-rinse phase and to spray the final-rinse liquid at a second, in particular average, final-rinse liquid temperature different from the first, in particular average, final-rinse liquid temperature in a second final-rinse sub-phase of the final-rinse phase.

15. Dishwasher (1) according to claim 14, wherein the dishwasher (1) has a control device which is designed to control the final rinse system of the dishwasher (1) for carrying out the method according to one of claims 1 to 13.

Images