Washing method having discontinuous dispensing of washing liquor, and dishwasher

Abstract

The invention relates to a method (100) for operating a dishwasher (1), wherein the dishwasher comprises a washing container (2) for receiving items to be washed, at least one spray device (19, 20, 21), a circulating pump (17) and a control device (22), wherein the spray device is arranged in / on the washing container in order to dispense washing liquor onto the items to be washed, and the circulating pump is designed to deliver washing liquor from a pump sump (15) of the washing container to the spray device, the method comprising: a loosening phase (S5), controlled by the control device, for loosening, by means of the washing liquor, soiling adhering to the items to be washed, wherein, during the loosening phase, the circulating pump is operated for discontinuous dispensing of the washing liquor from the at least one spray device; and a rinsing-off phase (S7) for rinsing off the soiling, wherein at least 75% of the washing liquor from the loosening phase is reused during the rinsing-off phase.

Description

[0001] Dishwashing process with discontinuous dispensing of dishwashing liquid and dishwasher

[0002] The present invention relates to a method for operating a dishwasher, also to a computer program product and finally to a dishwasher.

[0003] EP 1 362 545 B1 discloses a method for operating a dishwasher comprising a first program section with heated dishwashing liquid, followed by a second program section with cold dishwashing liquid. In the second program section, circulation is interrupted several times by repeatedly switching a circulation pump on and off.

[0004] EP 0 659 381 A1 discloses a method for operating a dishwasher, comprising a rinsing phase and / or a washing phase. In each of these phases, water is admitted to a sump of the dishwasher up to a static level. A pump has a suction opening below the static level and is operable to spray the water from spray nozzles. The pump is repeatedly switched on until a water level in the sump has dropped to a level of the suction opening of the pump, and then switched off. After each of these phases, a wastewater pump is subsequently switched on to drain the water from the sump. In this way, the amount of water required per phase can be reduced to, for example, 3 liters. As a result, a reduced amount of detergent can be added to the water.

[0005] Against this background, one object of the present invention is to provide an improved method for operating a dishwasher and / or a dishwasher configured to carry out the improved method. Particular attention is paid to increasing the efficiency of the method.

[0006] Accordingly, a method for operating a dishwasher, in particular a household dishwasher, is proposed. The dishwasher has a washing container for holding wash ware, at least one spray device, a circulating pump, and a control device. The spray device is configured in and / or on the washing container for dispensing wash liquor onto the wash ware. The circulating pump is configured to convey wash liquor from a pump sump of the washing container to the at least one spray device. The method comprises at least one dissolving phase and a rinsing phase. The dissolving phase and / or the rinsing phase are controlled by the control device. The dissolving phase is suitable for dissolving soils adhering to the wash ware using the rinsing liquor. During the dissolving phase, the circulating pump is operated to discontinuously dispense the rinsing liquor from the at least one spray device.The rinsing phase is suitable for rinsing off soils. At least 75% of the rinsing solution from the dissolving phase is reused during the rinsing phase.

[0007] The process proposed above includes a dissolving phase. During the dissolving phase, wash liquor is discontinuously dispensed onto the washware. A cleaning agent contained in the wash liquor is thus applied to soils adhering to the washware. This causes the soils to swell and dissolve. Subsequently, in the rinsing phase, the dissolved soils can be rinsed away with minimal energy consumption. As a result, the desired cleaning result is achieved with an efficient process.

[0008] The majority of the rinse liquor from the pre-dissolving phase is reused during the rinsing phase. This reduces water consumption throughout the entire rinse program and improves the efficiency of the process.

[0009] Preferably, the entire rinse solution from the dissolving phase is reused during the rinsing phase. This further increases the efficiency of the process.

[0010] A dishwashing program can, for example, contain various sub-program steps, such as a pre-wash, a cleaning or main wash, a final rinse and / or drying. Different dishwashing programs differ, for example, in the order and / or type of the sub-program steps, as well as in various operating parameters, such as a duration and / or a dishwashing liquor temperature of one or more sub-program steps. According to a further embodiment, it can be provided that the dissolving phase is a pre-wash or part of the pre-wash, and that the rinsing phase is a cleaning or part of the cleaning. In contrast to a conventional pre-wash with water, the proposed method already uses dishwashing liquor. This extends the duration of the cleaner's action on the soils and consequently improves the efficiency of the proposed method.

[0011] In particular, it can be provided that the rinsing phase, preferably a non-final part of the rinsing phase, is suitable for the continued dissolving of soils. By continuing to use the rinsing solution, any deposits still adhering to the items to be washed can continue to swell and / or be dissolved.

[0012] In order to simultaneously save water consumption and provide a highly concentrated rinsing liquor, it can be provided that the rinsing liquor contains 0.5 l (litres) to 2.0 l of water, preferably 1.2 l to 1.8 l of water and more preferably 1.5 l of water during the dissolving phase.

[0013] In order to provide a highly concentrated rinsing liquor, it can be provided in particular that the entire cleaning agent intended for and / or used in a rinsing program is contained and preferably dissolved in the rinsing liquor of the dissolving phase.

[0014] According to a further embodiment, the amount of wash liquor during the dissolving phase can be measured such that wash liquor is dispensed from the at least one spray device during the discontinuous dispensing over a period of time. The discontinuous dispensing preferably contains a pause period and an actual dispensing period that repeat alternately with one another. During a pause period, the circulating pump is operated or not operated, so that the wash liquor is not dispensed from the at least one spray device. During a dispensing period, the circulating pump is operated so that the wash liquor is dispensed from the at least one spray device. The dispensing over a period of time enables rapid and even moistening of the wash items and any buildup that is irregularly distributed in the wash tub.It may therefore be useful to distinguish between a discharge in the narrower sense of an outflow and a discharge in the broader sense of a procedural phase.

[0015] According to a further embodiment, the amount of rinsing solution during the dissolving phase can be determined such that, during the discontinuous operation of the dissolving phase, rinsing solution is released in the form of a spray from the at least one spray device. This has the advantage that the rinsing solution is not exchanged at the respective deposit, thereby better dissolving the deposit. Furthermore, a cleaner can be more concentrated in the rinsing solution.

[0016] Preferably, the amount of rinsing liquor during the dissolving phase is such that, during the discontinuous operation of the dissolving phase, rinsing liquor is only released in bursts from the at least one spray device. In contrast to discharging the rinsing liquor over a period of time, this embodiment requires a smaller amount of rinsing liquor. Starting with a constant amount of cleaner, the concentration of the cleaner in the rinsing liquor can thus be increased further. Thus, deposits can be dissolved or removed during the dissolving phase that could otherwise only be dissolved or removed with a very high expenditure of time, energy for generating pressure, energy for heating, and / or water, i.e., with lower efficiency.

[0017] It can be provided that, during the discontinuous dispensing, the wash liquor is dispensed simultaneously from only a portion of the multiple spray devices. For example, the dishwasher has a valve device that is configured and connected so that the control device can specify the supply of the wash liquor to one of the multiple spray devices or to a portion of the multiple spray devices. This can reduce the fill level of the supply lines between the circulation pump and the multiple spray devices.

[0018] Preferably, the amount of wash liquor during the dissolving phase is measured and / or the circulation pump is operated during the discontinuous discharge in such a way that a quantity of wash liquor sufficient to wet, or only to wet, the washware is dispensed by the at least one spray device. Preferably, the dissolving phase is carried out for the sole purpose of wetting the washware. "Wetting" the washware, including any deposits, means applying a very small volume of wash liquor. This allows the proportion of water in the wash liquor to be correspondingly low, so that ultimately a high concentration of detergent effectively dissolves the soils.

[0019] The above embodiments refer to a quantity of rinse liquor that allows for varying discontinuous dispensing. For a given amount of detergent, a smaller quantity of rinse liquor corresponds to a water saving. "Measured" can preferably be replaced by "dosed" or "limited."

[0020] When measuring the amount of rinsing solution, a delayed return flow of the rinsing solution discharged from the spray device(s) into the pump sump is preferably taken into account.

[0021] According to a further embodiment, the method provides for the circulation pump to be operated intermittently for the discontinuous discharge of the wash solution. The circulation pump is thus temporarily deactivated, thus saving electrical energy.

[0022] Preferably, the circulation pump is operated in a time-controlled manner for the discontinuous discharge of the wash liquor. The circulation pump's on-time lasts, in particular, 1 s (second) to 10 s. Additionally or alternatively, the circulation pump's off-time lasts, in particular, 1 s to 10 s. Experiments have shown that a dishwasher can be operated particularly efficiently with these time periods.

[0023] The control device is preferably configured and connected to detect the power consumption of the circulating pump. For example, a sensor can be configured and connected for this purpose. For example, the circulating pump itself can be configured and connected accordingly. Furthermore, it can be provided that the circulating pump is operated to discontinuously discharge the wash liquor depending on the detected power consumption of the circulating pump. In particular, it can be provided that the circulating pump is switched off depending on the power consumption. These options are based on the knowledge that idling of the pump sump may be accompanied by reduced power consumption by the circulating pump per unit of time. This enables the operation of the circulating pump to be regulated. For example, the backflow of the dispensed wash liquor varies depending on the type, quantity, and arrangement of the wash items in the wash tub.This more or less unpredictable variation can be addressed by the above control system, ensuring the proposed method runs efficiently. In a further development, the circulation pump can be switched off when there is a change in power consumption, indicating a transition from high-load operation to partial-load operation. This variant is particularly robust to operation.

[0024] According to a further embodiment, the dissolving phase transitions into the rinsing phase by adding water to the rinse liquor. By increasing the amount of rinse liquor, rinsing is improved through flow effects. By transitioning the dissolving phase into the rinsing phase, the duration of the rinse program is kept as short as possible.

[0025] According to a further embodiment, the rinsing liquor contains 2 to 4 liters of water during the rinsing phase, preferably 2.7 to 3.5 liters of water, and more preferably at least 3 liters of water. Experiments have shown that a particularly good rinsing effect is achieved using this amount of water or the corresponding amount of rinsing liquor.

[0026] The proposed method preferably comprises a preparation phase prior to the dissolving phase, during which the wash liquor containing water and detergent is prepared. During the dissolving phase, the wash liquor is distributed over the washware. By preparing the wash liquor prior to the dissolving phase, the most uniform concentration of detergent in the wash liquor and, ultimately, the most even distribution of detergent over the washware is achieved.

[0027] According to a further embodiment, the rinsing liquor has a heating device. One option is to heat the rinsing liquor during the dissolving phase by means of the heating device. This improves the dissolvability of certain soils, in particular grease. The lower the amount of rinsing liquor not used after the dissolving phase, the more efficient it is to heat the rinsing liquor during the dissolving phase. Furthermore, a computer program product is proposed which comprises instructions which, when executed by a computer, cause the computer to carry out the method described above. A computer program product, such as a computer program means, can be provided or delivered, for example, as a storage medium, such as a memory card, USB stick, CD-ROM, DVD, or in the form of a downloadable file from a server in a network.This can be done, for example, in a wireless communication network by transmitting a corresponding file with the computer program product or the computer program means.

[0028] According to a further aspect, a dishwasher is proposed. The dishwasher is, in particular, a household dishwasher. The dishwasher has a washing container for holding washware, at least one spray device, a circulation pump, and a control device. The spray device is arranged in and / or on the washing container for dispensing wash liquor onto the washware. The circulation pump is arranged for conveying wash liquor from a pump sump of the washing container to the at least one spray device.

[0029] The embodiments and features described for the proposed method apply accordingly to the proposed dishwasher.

[0030] Further possible implementations of the invention also include combinations of features or embodiments described above or below with respect to the exemplary embodiments not explicitly mentioned. In this case, the person skilled in the art will also add individual aspects as improvements or additions to the respective basic form of the invention.

[0031] Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the exemplary embodiments of the invention described below. The invention will be explained in more detail below using preferred embodiments with reference to the accompanying figures. Fig. 1 shows a schematic perspective view of an exemplary embodiment of a household dishwasher;

[0032] Fig. 2 shows a schematic sectional view of the household dishwasher according to Fig. 1 including a circulation pump and several spray devices;

[0033] Fig. 3 shows a flowchart of an embodiment of a method for operating a dishwasher, which is carried out by a control device of the household dishwasher of Fig. 1;

[0034] Fig. 4 shows schematically a volume-time diagram to illustrate the amount of rinsing liquor during a sequence of the method shown in Fig. 3;

[0035] Fig. 5 shows schematically a current-time diagram of a power consumption of a circulation pump during interval operation during a part of the sequence of the method shown in Fig. 3;

[0036] Fig. 6 shows schematically a level-time diagram of a pump sump level during the interval operation shown in Fig. 5;

[0037] Fig. 7 shows schematically a current-time diagram of a power consumption of a circulation pump during an interval operation during a part of the sequence of the method shown in Fig. 3; and

[0038] Fig. 8 shows schematically a level-time diagram of a pump sump level during the interval operation shown in Fig. 7.

[0039] In the figures, identical or functionally equivalent elements have been given the same reference numerals unless otherwise stated.

[0040] Fig. 1 shows a schematic perspective view of an embodiment of a system with a household dishwasher 1. The household dishwasher 1 comprises a washing container 2, which can be closed by a door 3, in particular in a watertight manner. For this purpose, a sealing device (not shown) can be provided between the door 3 and the washing container 2. The washing container 2 is preferably cuboid-shaped. The washing container 2 can be arranged in a housing of the household dishwasher 1. The washing container 2 and the door 3 can form a washing chamber 4 for washing dishes.

[0041] The door 3 is shown in its open position in Fig. 1. The door 3 can be closed or opened by pivoting about a pivot axis 5 provided at a lower end of the door 3. With the help of the door 3, a loading opening 6 of the washing container 2 can be closed or opened. The washing container 2 has a base 7, a ceiling 8 arranged opposite the base 7, a rear wall 9 arranged opposite the closed door 3 and two side walls 10, 11 arranged opposite one another. The base 7, the ceiling 8, the rear wall 9 and the side walls 10, 11 can be made, for example, from a stainless steel sheet. Alternatively, the base 7 can be made, for example, from a plastic material.

[0042] The household dishwasher 1 further comprises at least one dishware receptacle 12, 13, 14. Preferably, several, for example three, dishware receptacles 12, 13, 14 can be provided, wherein the dishware receptacle 12 can be a lower dishware receptacle or a lower basket, the dishware receptacle 13 can be an upper dishware receptacle or an upper basket, and the dishware receptacle 14 can be a cutlery drawer. As Fig. 1 further shows, the dishware receptacles 12, 13, 14 are arranged one above the other in the washing compartment 2. Each dishware receptacle 12, 13, 14 can be selectively moved into or out of the washing compartment 2. In particular, each dishware receptacle 12, 13, 14 can be pushed into the washing compartment 2 in an insertion direction E and pulled out of the washing compartment 2 in a pull-out direction A opposite to the insertion direction E.

[0043] Fig. 2 shows a highly schematic cross-section through the household dishwasher 1. For simplification, the dishware holders 12, 13, 14 are not shown in the cross-section.

[0044] The rinsing tank 2 has a pump sump 15, which, in the installed position, forms a level below the floor 7. From the pump sump 15, for example, a line 16 leads to a circulation pump 17. The line 16 is functionally a part of the pump sump 15. The pump sump 15 is connected via the line 16 to a suction connection of the circulation pump 17. Alternatively, it can be provided, for example, to arrange the circulation pump 17 at least partially directly on and / or in the pump sump 15. The pump sump 15 is connected upstream of the circulation pump 17.

[0045] In addition to the circulation pump 17, the household dishwasher 1 also includes, for example, a drain pump (not shown), which is preferably also connected to the pump sump 15. Unlike the circulation pump 17, a drain line, for example, is connected downstream of the drain pump to transport water, wash liquor, food residues, and / or the like out of the household dishwasher 1.

[0046] A pressure connection of the circulation pump 17, designed for fluid delivery, is connected to a pipe network 18, indicated only symbolically. The pipe network 18 is connected downstream of the circulation pump 17.

[0047] The pipe network 18 fluidically connects the circulation pump 17 to a plurality of spray devices 19, 20, 21. The spray device 19 is designed as a first spray arm arranged on the bottom 7 of the washing container 2. The spray device 20 is designed as a second spray arm arranged on the side wall 11 of the washing container 2. The spray device 21 is designed as a third spray arm arranged on the ceiling 8 of the washing container 2. This is a preferred example; more or fewer than three spray devices 19, 20, 21 can be provided; one or more or all of the spray devices can be designed not as a spray arm.

[0048] The circulation pump 17 is designed to supply the spray devices 19, 20, 21 with rinsing liquor F (see Fig. 2), the rinsing liquor F being pumped through the pipe network 18.

[0049] Furthermore, a control device 22 is shown, which is arranged, for example, on the door 3 of the household dishwasher 1. The control device 22 is configured, in particular, to operate the household dishwasher 1, for example, by the control device 22 executing at least one washing program.

[0050] For comparison with the proposed method described later, an exemplary conventional cleaning method is briefly described below. This begins by placing a small amount of detergent on the inside of the door and placing the remaining detergent in a compartment (not shown). For example, 3 g (grams) of detergent are placed on the inside and 19 g of detergent in the compartment. This is followed by the start of the washing program. Next, a certain amount of water is filled into the washing container under the control of, for example, the control device. This amount of water is conventionally sufficient to enable the circulation pump to circulate continuously. In technical terms, the amount filled is greater than a round-trip amount. For example, 3.1 l of water are filled. A pre-wash then begins.The water is continuously circulated, with the detergent arranged on the inside dissolving in the water to form the wash liquor. The circulation preferably takes place on alternating wash levels. In a next step, at least part of the wash liquor is pumped out by means of the drain pump and removed from the household dishwasher in order to remove coarse particles mixed into the wash liquor. For example, at least 0.4 l of wash liquor is pumped out. In a next step, a further amount of water is added to the wash liquor. For example, at least 0.7 l of water is added additionally. Preferably, more water is added than was pumped out in the previous step. In a next step, the detergent not previously added from the addition compartment is added to the wash liquor, which now contains, for example, 22 g of detergent and 3.4 l of water. Cleaning follows.During cleaning, the wash water is continuously circulated by the circulation pump. At the beginning of the cleaning process, the wash water is usually heated to a target temperature, which involves heating the washware and the wash tub to the same target temperature. The target temperature is, for example, 53 °C (degrees Celsius). Cleaning preferably takes place on alternating wash levels. At the end of the cleaning process, the entire wash water, including any food residue or soiling, is pumped out using the drain pump and thus removed. The pre-wash phase lasts, for example, 18 minutes, and the cleaning phase lasts, for example, 83 minutes. This is preferably followed by the final rinsing and drying phases of the wash program, which will not be discussed further here.

[0051] In addition, an exemplary course of a proposed method 100 for operating the household dishwasher 1, carried out by the control device 22 of the proposed household dishwasher 1, differs. This course is shown in Fig. 3.

[0052] In a first step S1, a quantity of cleaner is provided. This quantity of cleaner preferably contains the entire amount of cleaner intended for use or application until the end of the cleaning process. For example, 22 g of cleaner are provided.

[0053] In a next step S2, water is introduced into the rinsing tank 2. This amount of water is preferably measured so that continuous operation of the circulation pump 17 is not possible.

[0054] The amount of water introduced is preferably dimensioned such that the rinsing liquor F can be or is dispensed from the at least one spray device 19, 20, 21 during a discontinuous dispensing over a period of time, but not continuously.

[0055] According to a preferred option, even less water is introduced. Thus, the amount of water introduced can particularly preferably be such that, during discontinuous dispensing, the rinsing liquor F can be or is dispensed in bursts, but not continuously, from the at least one spray device 19, 20, 21.

[0056] When determining the amount of water introduced or to be introduced, the method 100 or the control device 22 preferably takes into account a residual amount of water or wash liquor that was not pumped out or could not be pumped out by the drain pump during a previous pumping operation. For example, it may be that the drain pump cannot pump below a level of an inlet into a working chamber of the drain pump. When determining the amount of water introduced or to be introduced, the method 100 or the control device 22 preferably takes into account an expansion of the volume of the wash liquor F as a result of heating the wash liquor.

[0057] According to a variant, 1.5 l of water are introduced into the rinsing tank 2 during step S2.

[0058] According to a preferred variant, during step S2, for example, water is introduced into the rinsing container 2 up to a filling level corresponding to a total volume of 1.5 l.

[0059] According to a further preferred variant, at least 0.5 l to at most 2 l of water are introduced into the rinsing container 2 during step S2.

[0060] According to another preferred variant, during step S2, for example, water is introduced into the rinsing container 2 up to a fill level corresponding to a total volume of at least 0.5 l to at most 2 l.

[0061] In a next step S3, the rinsing liquor F is prepared. For this purpose, for example, the water introduced into the rinsing tank 2 is mixed with the provided detergent so that the detergent dissolves in the water.

[0062] The steps S1 to S3 can also be carried out in an alternative order S2, S1, S3, or they can be replaced by at least one step in which the rinsing liquor F is provided in a different way.

[0063] In an optional next step S4, the rinsing liquor F and / or the rinsing container 2 are heated to a target temperature. For example, the rinsing liquor F and the rinsing container 2 are heated to a target temperature between 40°C and 80°C, preferably between 45°C and 60°C, for example, 53°C.

[0064] In a next step S5, the control device 22 controls the circulation pump such that the wash liquor F is dispensed discontinuously through the spray devices 19, 20, 21. "Discontinuous dispensing" is understood, in particular, to mean repeated and interrupted dispensing, for example, in the sequence dispensing - non-dispensing - dispensing. Preferably, step S5 includes a plurality of alternations between dispensing and non-dispensing.

[0065] Step S5 thus represents a dissolving phase controlled by the control device 22. The dissolving phase is suitable for dissolving or dissolving soils adhering to the items to be washed in the washing container 2 by means of the washing liquor F.

[0066] During the dissolving phase or step S5, the circulation pump 17 is operated in a manner described below. This mode of operation is suitable for discharging the spray liquor F discontinuously from the at least one spray device 19, 20, 21.

[0067] Step S4 may be omitted, it may be executed before step S5 and / or during step S5 including the end of step S5.

[0068] In a next step S6, additional water is introduced into the rinsing tank 2. In the present example, for example, 1.6 l of water are introduced into the rinsing tank 2.

[0069] According to a variant of the first embodiment, instead, in step S6, initially a maximum of 25% of the rinsing liquor F corresponding to, for example, 375 ml, preferably a maximum of 20% of the rinsing liquor F corresponding to, for example, 300 ml, more preferably a maximum of 10% of the rinsing liquor F corresponding to, for example, 150 ml and more preferably a maximum of 7% of the rinsing liquor F corresponding to, for example, 100 ml can be pumped out by means of, for example, the drain pump. This allows coarse soiling to be removed from the rinsing container 2 in order to facilitate subsequent process steps. After that, additional water is introduced into the rinsing container 2. In the present example, the amount introduced can correspond to 1.6 l plus the pumped-out volume, so that, for example, 1.975 l of water, preferably 1.9 l of water, more preferably 1.75 l of water and preferably 1.7 l of water are introduced into the rinsing container 2.

[0070] Because in step S6 no rinsing liquor F or at most 25% of the rinsing liquor F of step S5 is pumped out by means of the drain pump, for example, the corresponding amount or residual amount of the detergent is still available in order to completely remove any remaining soiling from the items to be washed during subsequent process steps.

[0071] In a next step S7, the circulation pump 17 is operated under the control of the control device 22 in order to rinse off the soiling. For this purpose, the circulation pump

[0072] 17, for example, is operated continuously. The circulation pump is thus operated in a manner suitable for rinsing off the soiling. Therefore, step S7 corresponds to a rinsing phase.

[0073] The terms "discontinuous release over a period of time" during the dissolving phase or during step S5 and "continuous operation" during the rinsing phase or during step S7 can be distinguished in terms of time or amount. For example, it can be provided that the "period" of release during the rinsing phase is a maximum of 10 s (seconds), whereas "continuous operation" should be at least 20 s.

[0074] Preferably, the "discontinuous dispensing over a period of time" and the "continuous operation" differ with respect to the amount of wash liquor F in the wash tub 2, in particular in the pump sump 15 and the line 16. During the discontinuous dispensing, the total amount of wash liquor F in the wash tub 2 and in particular in the pump sump 15 preferably does not allow a free choice of the duration of the period. Rather, design and / or operating parameters of the household dishwasher 1 preferably specify a maximum duration for a dispensing period during the discontinuous dispensing. The design and / or operating parameters that specify this maximum duration include, for example, the total amount of wash liquor 2 and / or a flow rate of the circulating pump 17 and / or dimensions of the pump sump 15 and the line 16 and / or dimensions of the piping network.

[0075] 18 and / or in particular a combination thereof. During the rinsing phase or during step S7, on the other hand, the continuous operation of the pump can be maintained for any length of time during the rinsing phase. The duration of the or each continuous operation of the circulating pump 2 is preferably predetermined by a desired rinsing effect and is therefore freely selectable. The circulating pump 17 is operated during the rinsing phase in a manner suitable for rinsing soils off the washware. The same applies to other controllable devices of the household dishwasher 1, for example devices for the targeted control and / or selective interruption of a fluid flow through the line network 18, and / or for example to an additional spray device, such as in particular a controllable intensive spray device.

[0076] The fact that the circulation pump 17 is operated during the rinsing phase to rinse soils off the washware does not, for example, preclude a continuation of the dissolving of deposits by the rinsing liquor F during this time. The fact that at least 75% of the rinsing liquor F of the dissolving phase is reused during the rinsing phase has, among other advantages, that the detergent contained therein already has a dissolving effect during the dissolving phase and continues to have a dissolving effect during the rinsing phase.

[0077] Step S5, or the dissolving phase, preferably constitutes a pre-rinse or preferably replaces the previously described form of pre-rinse. Accordingly, step S7, or the rinsing phase, preferably constitutes a cleaning or preferably replaces the previously described form of cleaning.

[0078] Below, the dissolving phase is compared with the pre-rinsing phase and the rinsing phase with the cleaning phase.

[0079] During the pre-dissolving phase, significantly less water or a smaller amount of rinse solution F is used than during the rinsing phase. In this respect, the pre-dissolving phase and the rinsing phase correspond to the pre-rinsing and cleaning phases.

[0080] During the dissolving phase, highly concentrated rinsing liquor F is used, whereas during the rinsing phase, medium-concentrated rinsing liquor F is used. For example, the rinsing liquor F of the dissolving phase contains 22 g of detergent dissolved in 1.5 l of water, whereas the rinsing liquor F of the rinsing phase contains 16.5 g to 22 g of detergent dissolved in 3.1 l of water. In this respect, the dissolving phase and the rinsing phase represent an improvement over the familiar pre-rinse with, for example, 3 g of detergent dissolved in 3.1 l of water and the familiar cleaning or cleaning with, for example, 21.6 g of detergent dissolved in 3.4 l of water. Although these figures refer to specific test conditions in case of doubt, they illustrate that the proposed process leads to a higher concentration of detergent, whereby soiling is dissolved more effectively.

[0081] During the dissolving phase, heating of the rinsing liquor F and thus early dissolving of greasy soils can be provided, whereas heating was previously only provided after the rinsing liquor had been replaced for the main cleaning for reasons of efficiency.

[0082] The dissolving phase according to the proposed method is designed to allow the highly concentrated wash liquor F to act on the soiling as early as possible. The dissolving phase is therefore primarily aimed at chemically dissolving the soiling. The known pre-rinse is designed to dissolve coarse soiling using a water jet or wash liquor jet and then remove it from the wash tub 2 as quickly as possible. The previously known pre-rinse is therefore primarily aimed at mechanically dissolving the soiling. The small amount of detergent in the wash liquor F in the known methods is, for example, calculated to prevent rinsed-off coarse soiling from re-adhering and in this case primarily serves to ensure long-lasting, smooth operation of the machine rather than early and rapid cleaning of the washware.

[0083] It should be noted that the proposed process results in time savings. Because the detergent is already present in the rinse solution F during the dissolving phase, the duration of the rinsing phase can be shortened compared to the cleaning phase in order to achieve the same contact time for the detergent on the soils.

[0084] Finally, a step S8 follows. In step S8, the wash liquor F, including any dissolved or floating soils, is pumped out of the domestic dishwasher 1 by means of the drain pump.

[0085] In a subsequent step S9, rinsing, drying and / or the like can take place.

[0086] Figure 3 shows the proposed method 100 in a quantity-time diagram. Progressive time is plotted along the abscissa axis labeled "t," and a quantity of the wash liquor F in the wash tank 2 is plotted along the ordinate axis labeled "V." The quantity is preferably a volume. The quantity is preferably a unit detectable by a sensor.

[0087] During steps S1, S2, S3, the control device 22 increases the amount of rinsing liquor F from 0 or close to 0 or a design-specified residual amount to a quantity V1. The quantity V1 corresponds, for example, to 1.5 l. The quantity V1 only allows for discontinuous dispensing of the rinsing liquor F.

[0088] During steps S4 and S5, the control device 22 performs the heating and dissolving phases. To illustrate the discontinuous dispensing of the wash liquor F during the dissolving phase, the flow rate in this area is shown as a zigzag line. However, the amount of wash liquor F in the wash tank 2 does not change due to the discontinuous dispensing.

[0089] The steps S1, S2, S3, S4 and S5 together last the time period T1, for example 18 min (minutes).

[0090] Subsequently, during step S6, the control device 22 increases the volume of the rinsing solution F again from the amount V1 to the amount V2. The amount V2 enables continuous dispensing of the rinsing solution F. The amount V2 corresponds, for example, to 3.1 l.

[0091] During step S7, the control device 22 performs the main cleaning or rinsing phase.

[0092] The steps S6 and S7 together last the time period T2, for example shorter than 83 min, such as between 65 min and 83 min.

[0093] During step S8, the control device 22 pumps out the rinsing liquor by means of the drain pump, so that the amount of rinsing liquor drops from V2 back to 0 or close to 0 or a design-specified minimum amount.

[0094] A control strategy is described below. Figure 5 shows a power consumption-time diagram illustrating intermittent operation of the circulation pump 17. Figure 6 shows a fill level-time diagram showing the temporal progression of a fill level H of the wash liquor F in the pump sump 15.

[0095] Interval operation occurs repeatedly during the triggering phase. Figures 5 and 6 do not necessarily show a beginning or end of the triggering phase.

[0096] Up to a time t0, the pump sump 15 is filled with the rinsing solution F up to an upper fill level HO. Before time t0, the circulation pump 17 is controlled by the control device 22 not to be switched on. Therefore, a power consumption I of the circulation pump 17 is at the low level IO.

[0097] At time t0, the circulation pump 17 is switched on by the control device 22. The power consumption I by the circulation pump 17 rises to level 11.

[0098] The circulation pump 17 pumps the rinse liquor F from the pump sump 15 into the pipe network 18. As the level of the rinse liquor F in the pipe network 18 rises, a counterpressure increases, which the circulation pump 17 must overcome. Therefore, the circulation pump 17 switches to full-load operation, and the power consumption increases to the highest value I4. Meanwhile, the fill level H drops to the lower fill level HU.

[0099] In this embodiment, the quantity V of rinsing liquor F in the rinsing container 2 is precisely dimensioned so that only a burst-like discharge of the rinsing liquor F from the spray nozzles 19, 20, 21 is possible. This moment t1 is referred to as the spray burst 23 or, in technical terms, as a "spray brush."

[0100] The fill level H has dropped to the lower fill level HU, so the circulation pump 17 no longer receives a volume flow of rinse liquor F from the pump sump 15 corresponding to the delivery flow. Therefore, at this moment t1, the circulation pump 17 switches to partial load operation, and the power consumption drops from the high level I4 to the lower level I3. This drop in power consumption I is detected by the circulation pump 17 or a sensor and reported to the control device 22.

[0101] While the filling level H remains at the value of the lower filling level HU and the power consumption I continues to decrease from the level I3 to the level N2, the control device 22 terminates operation of the circulation pump 17.

[0102] As a result, at a moment t2, the circulation pump 17 is switched off and the power consumption I drops from the level I2 to the initial level IO.

[0103] Because the circulation pump 22 is switched off, it does not pump any rinsing liquor F into the pipe network 18. As a result, the filling level H in the pump sump 15 rises again to the upper filling level HO.

[0104] Because the control device 22 detects, via a fill level sensor or as a result of waiting a predetermined period of time, that the fill level has risen again, the control device 22 switches the circulation pump 17 on again at a time t3. The described cycle begins again. The time t3 of a previous cycle is preferably a time t0 of a subsequent cycle.

[0105] For example, a time period Z1 from t0 to t2 lasts 5 s (seconds) and a time period Z2 from t2 to t3 lasts 2 s. A cycle time therefore lasts 7 s, for example.

[0106] The repetitions of the cycle from t0 to t3 are referred to as interval operation of the circulation pump 17.

[0107] The interval operation described in this embodiment is a preferred example of interval operation.

[0108] In a variant of the second embodiment, the time periods Z1 and / or Z2 can also be predetermined individually. In this respect, a corresponding sensor can be used, and the control device 22 can implement a time control for the interval operation.

[0109] The control system of Figs. 5 and 6 is shown again in Figs. 7 and 8. However, a larger quantity V1 of rinse liquor F is provided in the rinse tank 2. This has the consequence that, instead of the spray burst 23, the rinse liquor F can be dispensed from the spray devices 19, 20, 21 over a time period Z3 before the fill level H has dropped to the lower fill level HU. As a result, in the situation shown in Figs. 7 and 8, the circulating pump 17 switches to partial load operation, therefore consuming less power, and is switched off by the control device 22. In other words, in the situation in Figs. 7 and 8, the spray liquor F is also dispensed discontinuously and the circulating pump 17 is operated in interval mode.

[0110] According to a further embodiment not shown in the figure, the circulation pump 17 is not switched off by the control device 22 during partial load operation, but rather the circulation pump 17 continues to be operated by the control device 22 in partial load operation. As a result, the pipe network 18 remains partially filled. If the circulation pump 17 is then operated again in full load operation by the control device 22, rinsing liquor F can be released more quickly from the spray devices 19, 20, 21. The time period Z1 can thus be reduced.

[0111] Although the present invention has been described using exemplary embodiments, it can be modified in many ways.

[0112] Reference symbols used:

[0113] 1 household dishwasher

[0114] 2 rinsing containers

[0115] 3 Door

[0116] 4 rinsing chamber

[0117] 5 swivel axis

[0118] 6 Loading opening

[0119] 7 Floor

[0120] 8 Ceiling

[0121] 9 Rear wall

[0122] 10 Side wall

[0123] 11 Side wall

[0124] 12 Dishwasher waste holder

[0125] 13 Dishwasher drawer

[0126] 14 Dishwasher waste holder

[0127] 15 Pump sump

[0128] 16 Line

[0129] 17 Circulation pump

[0130] 18 pipeline network

[0131] 19 Spray device

[0132] 20 spray device

[0133] 21 Spray device

[0134] 22 Control device

[0135] 23 sprays

[0136] 100 procedures

[0137] A Extension direction

[0138] E Insertion direction

[0139] F Rinse liquor

[0140] H Filling level

[0141] HO upper filling level

[0142] HU lower fill level

[0143] I Power consumption

[0144] 11 Level 12 Level

[0145] 13 Level

[0146] 14 Level t Time

[0147] T1 duration

[0148] T2 Duration tO Time t1 Time t2 Time t3 Time

[0149] V Quantity

[0150] VI Quantity

[0151] V2 Quantity

[0152] Z1 time span

[0153] Z2 time span

[0154] Z3 time span

Claims

PATENT CLAIMS 1. Method (100) for operating a dishwasher (1), in particular a household dishwasher (1), wherein the dishwasher (1) has a wash tank (2) for receiving items to be washed, at least one spray device (19, 20, 21), a circulation pump (17) and a control device (22), wherein the at least one spray device (19, 20, 21) is arranged in and / or on the wash tank (2) for dispensing wash solution (F) onto the items to be washed, and wherein the circulation pump (17) is arranged for pumping wash solution (F) from a pump sump (15, 16) of the wash tank (2) to the at least one spray device (19, 20, 21), wherein the method (100) comprises: a dissolving phase (S5) controlled by the control device (22) for dissolving soiling adhering to the items to be washed by means of the wash solution (F),wherein during the dissolving phase (S5) the circulation pump (17) is operated to discontinuously discharge the rinsing solution (F) from the at least one spray device (19, 20, 21), and a rinsing phase (S7) to rinse off the soiling, wherein at least 75% of the rinsing solution (F) of the dissolving phase (S5) is reused during the rinsing phase (S7).

2. Method according to claim 1, characterized in that the entire rinsing liquor (F) of the dissolving phase (S5) is reused during the rinsing phase (S7).

3. Method according to one of the preceding claims, characterized in that the dissolving phase (S5) is a pre-rinsing or part of the pre-rinsing, and that the rinsing phase (S7) is a cleaning or part of the cleaning.

4. Method according to one of the preceding claims, characterized in that the quantity (V1) of the rinsing liquor (F) during the dissolving phase (S5) is dimensioned such that rinsing liquor (F) is dispensed from the at least one spray device (19, 20, 21) during the discontinuous dispensing over a period of time (Z3).

5. Method according to one of the preceding claims, characterized in that the quantity (V1) of the rinsing liquor (F) during the dissolving phase (S5) is dimensioned such that during the discontinuous dispensing, rinsing liquor (F) is dispensed in the form of a spray (23) from the at least one spray device (19, 20, 21).

6. Method according to one of the preceding claims, characterized in that the quantity (V1) of the rinsing liquor (F) during the dissolving phase (S5) is dimensioned such that the circulation pump (17) is operated during the discontinuous dispensing such that a quantity of rinsing liquor (F) dimensioned for wetting the items to be rinsed is dispensed from the at least one spray device (19, 20, 21).

7. Method according to one of the preceding claims, characterized in that the circulation pump (17) is operated in interval mode for the discontinuous delivery of the flushing liquor (F).

8. Method according to one of the preceding claims, characterized in that the circulation pump (17) is operated in a time-controlled manner for the discontinuous discharge of the rinsing liquor, wherein a switch-on time (Z1, Z3) of the circulation pump (17) lasts in particular 1 s to 10 s, and / or wherein a switch-off time (Z2) of the circulation pump (17) lasts in particular 1 s to 10 s.

9. Method according to one of the preceding claims, characterized in that the control device (22) detects a current consumption (I) of the circulation pump (17) and the circulation pump (17) is operated for discontinuous delivery of the rinsing liquor (F) depending on the detected current consumption (I) of the circulation pump (17).

10. Method according to claim 9, characterized in that the circulation pump (17) is switched off when there is a change in the current consumption (I) which indicates a transition from high load operation to partial load operation.

11. Method according to one of the preceding claims, characterized in that the dissolving phase (S5) transitions into the rinsing phase (S7) by adding (S6) water to the rinsing liquor (F).

12. Method according to one of the preceding claims, characterized in that the method (100) has a preparation phase (S3) before the dissolving phase (S5), during which the rinsing liquor (F) containing water and cleaner is prepared.

13. Method according to one of the preceding claims, characterized in that the dishwasher (1) has a heating device, and that the washing liquor (F) is heated (S4) by means of the heating device during the dissolving phase (S5).

14. Computer program product comprising instructions which, when the program is executed by a computer, cause it to execute the method (100) according to any of the preceding claims.

15. Dishwasher (1), in particular a household dishwasher (1), comprising a wash container (2) for receiving items to be washed, at least one spray device (19, 20, 21), a circulation pump (17) and a control device (22), wherein the spray device (19, 20, 21) is arranged in and / or on the wash container (2) for dispensing wash liquor (F) onto the items to be washed, and wherein the circulation pump (17) is arranged for pumping wash liquor (F) from a pump sump (15, 16) of the wash container (2) to the at least one spray device (19, 20, 21), characterized in that the control device (22) is arranged for carrying out the method (100) according to one of claims 1 to 13.

Images