EP1699340B1 - Dishwasher with an intermediate pump mode - Google Patents

Description

The invention relates to a method for operating a dishwasher with at least one rinsing container, a circulating pump for conveying rinsing liquid to at least one spraying device for loading rinsing items to be cleaned stored in the rinsing container, a rinsing pump for pumping rinsing liquid out of the dishwasher and having at least one Subprogram steps pre-cleaning, cleaning, rinsing and drying of a mixable rinse program.
Dishwashers usually have at least one rinsing container and spray devices arranged therein, wherein the spray devices are charged with the rinsing liquid conveyed by a circulating pump in order to apply rinsing liquid to the rinsing products stored in the rinsing container. In the known dishwashing washing programs are usually selectable via a program control unit, which can be assembled, for example, from the partial program steps pre-cleaning, cleaning, rinsing and drying.

The items to be cleaned can also include heavily soiled pots, pans or cooking utensils made of stainless steel, enamel, jenaglas or iron, the surfaces of which are often covered with burnt-in food residues. The burnt-in food residues usually consist of partially burnt starch, fat, protein or fiber residues or residues of food cooked in the pots and pans. Another frequently occurring type of soiling are limescale edges or limestone layers adhering to the surfaces of the items to be washed. The known methods for operating dishwashers have the disadvantage that heavy soiling of the type mentioned above is not or only insufficiently removed from the items to be washed.

From the EP 0 842 632 A2 For example, a dishwashing machine with a tub and a suds pump is known for pumping rinse liquor into a spray arm. To remove dirt from the rinsing a dirt collector is provided. The dirt is separated under the action of a centrifugal force from the rinse liquor and passed a sample of the rinse liquor with high dirt content on a Schmutzabtrennkanal, whose upper end wall is formed by a filter screen. While water enters the lower tub area through the filter screen, the dirt in the separation channel remains and settles in a collecting area. If a pressure in the collection area exceeds a predetermined limit indicating an added filter screen, a drain pump is energized to clean the screen. The drain pump sucks lye with high dirt content from the collection area and pumps it to a drain.

The present invention is therefore based on the object to provide a method with which it is possible to operate a dishwasher so that even heavy dirt, for example in pots, pans and cooking utensils are removed from the dishes. Another object of the present invention is to design the washing program sequence of a dishwasher so that even with heavy amounts of flushing residues at the end of the wash program, the removed food particles are removed from the dishwasher.

This object is achieved by the inventive method for operating a dishwasher with the features of claim 1. Advantageous developments of the invention are characterized in the subclaims 2 to 9.

According to the present invention, a method is provided for operating a dishwasher with at least one rinsing container, a circulating pump for conveying rinsing liquid to at least one spraying device for loading rinsing items to be cleaned stored in the rinsing container, a rinsing pump for pumping rinsing liquid out of the dishwasher and having one at least from the partial program steps pre-cleaning, cleaning, rinsing and drying composable rinse program, wherein during a partial program step, at least temporarily, the drain pump is activated.

The method according to the invention makes it possible, especially during the cleaning phases of the washing program, to remove the accumulated rinsing residues early from the rinsing liquid and to remove them from the dishwasher. As can be seen from the following description, the rinsing liquor is thereby relieved of rinsing residues, in particular in heavily soiled items, which improves the cleaning performance of the dishwasher. Furthermore, the method according to the invention causes the removed food particles to be removed from the dishwasher even in the case of heavy soiling of the items to be washed at the end of the washing program. A further advantage of the present invention is that the energy required for the operation of the dishwashing machine is reduced due to the avoidance of perturbation-related impairments in the circulation of the rinsing liquid and the reduction of the total running time of the rinsing program.

In the case of heavily soiled items, sink residues accumulate in larger quantities, which usually accumulate on the bottom of the washing container. There, the rinsing residues absorb the cleaning agent dissolved in the rinsing liquid, thus reducing the content of cleaning agent in the rinsing liquid and thus reduce the cleaning power on the remaining food to be removed on dishes. Therefore, in the method according to the present invention by the at least temporary activation of the drain pump during a partial program step an intermediate pumping is performed, wherein the accumulated in the sump at the bottom of the washing rinse residues are conveyed from the dishwasher. This reduces the amount of rinsing residues contained in the dishwasher and in the rinsing liquid and also reduces the absorption of cleaning agent from the rinsing liquid.

Experience has shown that dried or baked food remains in pots, Pans or cookware an affinity for clear water, ie that a food residue surface quickly absorbs water. This creates a smooth surface that is more resistant to the action of detergents and thus complicates the removal of food particles from the dishes. In order to prevent this, in a preferred embodiment of the invention, the rinsing liquid is mixed with cleaning agent or rinse aid right at the beginning of a partial program step. As a result, the food residue surface to be removed is already wetted with an alkaline solution at the beginning of the rinsing operation, before a surface resistant to cleaning agents can be formed on the food residues by absorption of clear water.

In a further preferred embodiment of the method according to the invention, the rinsing liquid, in particular after the intermediate pumping operation of the rinse pump, is temporarily or continuously added to cleaning agent or rinse aid during a partial program step. The temporary or continuous addition of cleaning agent or rinse aid ensures that, even after the performance of an intermediate pumping operation in which the rinsing liquid is partly conveyed out of the dishwasher via the rinsing pump, a sufficient concentration of cleaning or rinsing fluid is achieved for the further course of the respective subprogram step Rinse aid is present in the rinse liquid.

A similar effect can be achieved if the cleaning agent and / or the rinse aid of the rinsing liquid is preferably added in the form of a slowly dissolving tablet or a so-called tab, so that the cleaning agent or rinse aid of the rinsing liquid is continuously added during a partial program step. The slow and continuous supply of cleaning agent or rinse aid ensures that after the Abpumpvorgängen the intermediate pumping in the further course of the rinse, the concentration of cleaning or rinse aid in the rinse is rebuilt.

In a particularly preferred embodiment of the method according to the invention, a simultaneous operation of the circulation pump and the drain pump is at least temporarily carried out during a partial program step. By the operation of the circulation pump on the one hand, the spraying devices are charged with rinsing liquid and thereby collected the already detached from the items to be washed flushing residues at the bottom of the washing. By operating the drain pump, the rinsing residues are conveyed out of the dishwasher together with a part of the rinsing liquid. In this way, during a partial program step, a type of floating operation is carried out, in which the flushing residues are collected in the sump at the bottom of the washing container and then via the suds pump in the intermediate pumping operation from the dishwasher to get promoted.

It can also be provided in the washing several spray devices that are operated at least temporarily simultaneously or alternately during a partial program step. For example, an upper sprayer for an upper rack and a lower sprayer for an upper rack may be provided. To support an efficient implementation of the Schwemmbetriebs, in which the flushing residues detached from the dishes are collected at the bottom of the washing, for example, only the lower sprayer can be operated to collect the flushing residues through targeted Spülflüssigkeitsstrahlen in the sump.

In the method according to the invention, it can also be provided that fresh water is supplied to the rinsing fluid circuit at least temporarily by opening a filling valve during a partial program step. The opening of the filling valve for the supply of fresh water can be carried out at least temporarily even during operation of the circulation pump. This can be prevented, for example, that the Spülflüssigkeitsmenge is too low in the course of the relevant part program step, especially after a Zwischenpumpbetrieb the drain pump.

A particularly good rinsing result can be achieved if after each partial program step with rinsing liquid insert a substantially complete rinsing liquid change is made. This can be accomplished, for example, by discharging the rinsing liquid essentially completely from the dishwasher via the suds pump at the end of a subprogram step and supplying fresh water at the beginning of a subsequent subprogram step with a rinsing liquid insert.

In a further preferred embodiment of the method according to the invention, a comminution device (food crusher) for comminuting flushing residues is activated at least temporarily during operation of the drain pump. After the flushing residues have accumulated in the floating operation, as described above, in the sump, the food particles are there crushed using the crushing device and pumped through the drain pump from the dishwasher. Thereby Larger flushing residues can also be crushed and transported out of the dishwasher via the drain pump and the sewer line.

A dishwasher which is able to carry out the method according to the invention is preferably equipped with at least two spray devices which can be charged simultaneously or alternately with rinsing fluid from the circulation pump. Furthermore, it is advantageous if the dishwasher a comminution device for comminution of flushing residues, which is at least temporarily activated during a partial program step.

In the following, the present invention will be explained in more detail with reference to preferred embodiments with reference to the accompanying drawings. Show it:

FIG. 1 a diagram illustrating the operation of the circulation pump and the Zwischenpumpbetriebs the drain pump in a method for operating a dishwasher according to a preferred embodiment of the present invention;

FIG. 2 a schematic representation of a part of in FIG. 1 shown method of operating a dishwasher according to a preferred embodiment of the present invention.

FIG. 1 1 is a diagram showing the operation of the circulation pump and the intermediate pumping operation of the suds pump in a method of operating a dishwasher of the present invention according to a first preferred embodiment. In the diagram of FIG. 1 the time t is plotted on the X-axis and the temperature of the rinsing liquid in ° C on the Y-axis. The diagram of FIG. 1 further includes a curve U, which represents the time course of the activity of the circulation pump in the course of the washing program according to the invention in a preferred embodiment. This curve U can also be found in the implementation of the intermediate pumping operation Z.

As in FIG. 1 To recognize the wash program of this embodiment comprises three sub-program steps, such as pre-cleaning, cleaning and rinsing / drying, the individual part program steps can be divided into several subsections. In the present exemplary embodiment, for example, the pre-cleaning subprogram step is subdivided into three subsections V ₁ , V ₂ , V ₃ and the subprogram step rinse / dry into two subsections K ₁ and K, wherein the subprogram step cleaning comprises only one section R ₁ . The first subsection V ₁ of the preprogramming subprogram step begins with the introduction of fresh water into the dishwasher, wherein the fresh water is immediately mixed with cleaning agent to produce a rinsing eye. The rinsing liquid is first heated in the course of the first subsection V ₁ to a temperature of about 50 ° C and heated in the course of the rinse program to a temperature of up to 70 ° C.

As can be seen on the curve U for the time profile of the activity of the circulation pump, the circulation pump during the entire subsection V ₁ in operation to supply the spray devices in the washing of the dishwasher with pressurized flushing liquid. The remaining subsections V ₂ , V ₃ , R ₁ , K ₁ , K ₂ have a very similar to the first subsection V ₁ course and differ only in their duration. During each subsection V ₁ , V ₂ , V ₃ , R ₁ , K ₁ , K ₂ , one or more intermediate pumping operations may be carried out according to the method of the invention. The intermediate pumping operation may take place at any time in the subsection of the subprogram step and during the operation U of the circulating pump. During the intermediate pumping operation, the suds pump is activated at least temporarily in order to convey the rinsing residues accumulated in the sump at the bottom of the rinsing container during the rinsing operation, and thus to achieve the effects described above.

FIG. 2 is a schematic representation of a subsection V ₁ , V ₂ , V _{3 ,} R ₁ , K ₁ or K ₂ of in FIG. 1 illustrated method for operating a dishwasher according to a preferred embodiment of the present invention. A subsection V ₁ , V ₂ , V ₃ , R ₁ , K ₁ or K _{2 of} a subprogram step is subdivided into the three operating modes, the idle mode, the intermediate pump mode and the idle pump mode. In the floating mode, the rinsing residues removed from the items to be washed are collected in the sump at the bottom of the rinsing container. In the intermediate pumping mode, the rinsing residues are transported out of the sump by temporarily activating the suds pump from the dishwasher and in the pumping mode, the rinsing liquid is substantially completely pumped out of the dishwasher. In FIG. 2 the operation of the circulation pump, the drain pump, the spraying devices and the comminution device is characterized by a crossbar in the respective row of a matrix consisting of the vertical bars for subdivision of subsections mode of flow, intermediate pumping mode and empty pumping mode and horizontal lines representing the operation of each Circulation pump, the drain pump of the separate spray devices and the crushing device is formed.

A bar in the line of the circulation pump indicates the operation of the circulation pump and the length of the bar corresponds analogously to the duration of the operation of the circulation pump and thus the circulation operation during the respective subsections of the flow mode, intermediate pumping mode and empty pumping mode. A bar in the line of the drain pump indicates the operation of the drain pump and the length of the bar corresponds to the duration of the operation of the circulation pump and thus the Abpumpbetriebs during the subsections concerned intermediate pumping mode and empty pumping mode. A bar in the line of the separate spraying devices indicates the operation of the spraying devices and the length of the bar corresponds to the duration of the operation of the separate spraying devices and thus the loading of the dishes with washing liquid during the subsection concerned Intermediate pumping mode. A bar in the line of the comminution device characterizes the operation of the comminution device and the length of the bar corresponds to the duration of the operation of the comminution device and thus the comminution of flushing residues during the respective subsections intermediate pumping mode and empty pumping mode.

As already in the description too FIG. 1 explained, so too FIG. 2 it can be seen that during the subsections mode of operation, intermediate pumping mode and idle pumping mode, the circulating pump is essentially in continuous operation. By operating the circulating pump and thus the spraying devices, the dishwashing residues distributed in the dishwasher are gathered in the pump pot of the dishwasher during the mode of operation. During the intermediate pump mode, the circulation pump and the drain pump are at least temporarily activated simultaneously. As a result, during the circulation operation, flushing residues together with a part of the flushing liquid are conveyed out of the dishwasher via the drain pump, which brings about the advantages described above.

In the intermediate pumping mode subsection, the separate spray devices are separated and operated alternately to assist in collecting flushing residues in the sump at the bottom of the wash tub. Both in the sub-section intermediate pumping mode and in the sub-section empty pumping mode, the comminuting device is activated at least temporarily during operation of the suds pump in order to comminute the flushing residues accumulated in the sump at the bottom of the sump and thus better to be able to be conveyed out of the dishwashing machine. Ultimately, in the last subsection empty pump mode, only the drain pump is in operation in order to convey the washing liquid completely out of the dishwasher at the end of the respective partial program step or lower section. The essentially complete replacement of the rinsing liquor between the partial program steps or between the subsections of the partial program steps improves the cleaning performance of the dishwasher.

List of reference numbers

• V ₁ first part program step in the pre-cleaning phase
• V ₂ second part program step in the pre-cleaning phase
• V ₃ third partial program step in the pre-cleaning phase
• R ₁ first part program step in the main cleaning phase
• R ₂ second part program step in the main cleaning phase
• K ₁ first part program step in the final rinse phase
• K ₂ second part program step in the rinse phase
• t time
• T Temperature curve of the rinsing fluid during the washing program
• U Activity of the circulation pump
• Z intermediate pumping operation

Claims (9)

1. Method for operating a dishwasher with at least one wash container, a circulating pump for conveying wash fluid to at least one spray apparatus for application to items to be washed that are accommodated in the wash container, a drain pump for pumping wash fluid out of the dishwasher and a wash program that can be made up at least of the program substeps prewash (V₁, V₂, V₃), wash (R₁), fmal rinse (K₁, K₂) and dry, wherein the drain pump is activated at least periodically during a program sub-step (V₁, V₂, V₃, R₁, K₁, K₂), characterised in that intermediate pumping is performed by the at least partial activation of the drain pump, during which wash residues that have collected in a pump sump at the base of the wash container, where they can absorb a detergent that has dissolved in the cleaning fluid, are conveyed out of the dishwasher.
2. Method according to claim 1, wherein at the start of a program sub-step (V₁, V₂, V₃, R₁, K₁, K₂) detergent or rinse aid is added to the wash fluid.
3. Method according to one of claims 1 or 2, wherein after operation of the drain pump during a program sub-step (V_1, V₂, V₃, R₁, K₁, K₂) detergent or rinse aid is added periodically or continuously to the wash fluid.
4. Method according to one of the preceding claims, wherein the detergent and/or rinse aid is/are added to the wash fluid preferably in the form of a slowly dissolving tablet or tab, so that the detergent or rinse aid is added continuously to the wash fluid during a program sub-step (V₁, V₂, V₃, R₁, K₁, K₂).
5. Method according to one of the preceding claims, wherein the circulating pump and drain pump are operated in a simultaneous manner at least periodically during a program sub-step (V₁, V₂, V₃, R₁, K₁, K₂).
6. Method according to one of the preceding claims, wherein at least two spray apparatuses are provided in the wash container and are operated in a simultaneous or alternating manner at least periodically during a program sub-step (V₁, V₂, V₃, R₁, K₁, K₂).
7. Method according to one of the preceding claims, wherein fresh water is supplied at least periodically during a program sub-step (V₁, V₂, V₃, R₁, K₁, K₂).
8. Method according to one of the preceding claims, wherein the wash fluid is discharged essentially completely from the dishwasher preferably by way of the drain pump at the end of a program sub-step (V₁, V₂, V₃, R₁, K₁, K₂).
9. Method according to one of the preceding claims, wherein a comminution apparatus for the comminution of wash residues is activated at least periodically during operation of the drain pump.

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