Method for operating a dishwashing machine with at least one programme step drying

ES 2 602 183 T3

PROCEDURE TO OPERATE A DISHWASHER WITH AT LEAST ONE PROGRAM STAGE

PARTIAL "DRYING"

DESCRIPTION

The invention relates to a method for operating a dishwasher with at least one "drying" partial program stage.

Different processes are known to dry, for example, parts to be washed in a dishwasher. For example, the pieces to be washed can be dried by means of internal heat drying, when the washing liquid is heated in a partial program stage "rinse" and thus the rinsed heated dishes dry themselves during the drying process by means of heat. Internal of the dishes thus generated. To achieve this drying with internal heat, the washing liquid is heated in the rinsing partial program stage, for example in a heat exchanger, to a specified temperature and is guided by means of spraying devices to the parts to be washed. Due to the relatively high temperature of the washing liquid in the partial rinse program stage of usually 65 ° C to 75 ° C, it is possible to transmit a sufficient amount of heat to the parts to be washed, whereby the water adhering to the dishes evaporate due to the heat accumulated in the pieces to be washed.

In other known procedures for drying parts to be washed in a dishwasher, a separate heat source, for example a hot air fan, is used to heat the wet air mixture in the drying process, so that the air in the wash tub can absorb more water.

Dishwashers are known in which humid air is blown out. This is a drawback, since the surrounding kitchen furniture is damaged.

For this reason, other methods are known in which, before evacuating the humid air, it is led through condensing surfaces, in which the humidity is condensed. This condensation water is led either to the wash basin or to special collection containers.

From DE 20 16 831 A1 a method of the type mentioned at the beginning is known for dishwashers, in which the air from the wash tub is led through an opening that can be closed by the wall of the laundry tub. to a reversibly dehydrated material and from there through an opening to the outside. The desorption of the reversibly dehydrated material takes place during the stop phase of the apparatus, however the water vapor which then forms is again guided out through the opening. As has already been described, this is a drawback, since the surrounding kitchen furniture is damaged.

A drawback of the above-described heating system corresponding to the above-described state of the art consists in that the heating of the washing liquid involves a large consumption of energy and the heat energy necessary for each heating phase has to be generated by the electric heating elements. Likewise, known heating systems have the disadvantage that the heating of the washing liquid in the rinsing partial program stage, as well as the development of the drying partial program stage itself, involve a large energy consumption and heat energy is lost. necessary after the drying process.

The laundry and washing treatment apparatus of DE 36 26 887 A1 has an air duct system with air duct control elements, in which a container filled with an adsorptive drying medium can alternately be connected to a process air flow to be dehumidified and a regeneration air flow. In a regeneration phase, air from the relatively dry environment is led from outside through an air duct by means of a fan to the container filled with drying medium. Heat is then conducted for regeneration to the drying medium by means of a heating device located in the air conduction channel, through which the ambient air is sucked in by means of the fan. After passing through the adsorptive drying medium, the regeneration air, which absorbs moisture from said medium and is therefore humid, is sent through an air outlet channel to the outside.

In the dishwasher of DE 38 30 664 A1, washing liquid to be heated is driven by a pump to carry out a washing process through a flow heater in a dispenser and spray system and is sprayed into the washing tub . A hollow cylinder is arranged around the passage heater as a drying vessel, which is filled with a drying medium which adsorbs moisture and is in thermal contact with the passage heater. The connection on the inlet side of the drying container is connected by an air line to an outlet of the wash tub on the roof side. In this air duct a fan is inserted. Through its connection on the outlet side, the drying container is connected to an ejection opening which opens into the wash tub. The air duct is equipped with a closure, which interrupts the air circulation during washing. After finishing the washing process based on the spray of the washing liquid, the air containing high humidity during a drying process is blown from the washing tub by the fan now connected to the drying vessel. The drying medium stored in the drying container absorbs the moisture from the air flowing through the drying container and the air dried in this way is blown through the connection on the outlet side of the drying container and the discharge opening. to the wash basin.

ES 2 602 183 T3

It is the objective of the present invention to provide a method with which it is possible to operate a dishwasher as economically as possible, efficiently dry the units placed therein, as well as keep the energy consumption that this implies as low as possible.

This objective is achieved by the method corresponding to the invention with the characteristics of claim 1. Advantageous improvements of the present invention are characterized in the sub-claims.

In the procedure corresponding to the invention for operating a dishwasher with at least one drying partial program stage, air from a treatment chamber is conducted in the partial drying program stage, of which there is at least one, through a column of sorclon and is taken to the treatment chamber, the sorclon column containing material reversibly dehydrated and moisture being extracted from the air during the passage through.

In an advantageous variant of this method, the air is heated during the passage through the sorclone column by means of heat of condensation and, if necessary, additionally heated by means of a heater.

By using reversibly dehydrating material with hygroscopic properties, for example ceollta, it is normally not necessary to heat the units to be treated in the partial program stage preceding the drying partial program stage, for example in a dishwasher in the drying stage. partial program cleared. This enables considerable energy savings. However, heating to low temperatures, for example up to 30 ° C, is still appropriate during rinsing. By heating the air by means of the sorclone column, in which the condensing part of the calorific vapor is released, its moisture absorption capacity increases at each pass through the sorclone column, which improves the result of drying and shortens the drying time. An additional heating of the air with an additional heater in the drying partial program stage beyond heating with the sorclone column and thus for example also the dishes in the dishwasher, is normally not necessary, because the heat energy released in the sorclone column is sufficient to heat the air to high temperatures, for example 70 ° C. The sorclone column is heated by the heat of condensation at elevated temperatures, for example 150 ° C.

In the preferably closed air system, a floor air exchange from the environment is completely excluded, thus preventing the units to be treated from becoming soiled again. With the present invention a method is provided with which it is possible to operate apparatus of the type mentioned at the beginning in the most economical way possible, to dry the units to be dried efficiently, as well as to keep the energy consumption that this implies as low as possible. possible.

According to a feature of the invention, air is led from the treatment chamber through the sorclone column and into the treatment chamber for the desorption of the reversibly desorbing material and is blown during the passage through.

As is known, the reversibly desorbing material is heated for desorption to very high temperatures, for which heat energy is required. The accumulated liquid then comes out as hot water vapor. The water vapor is preferably conveyed with an air flow into the treatment chamber of the device and the air in the treatment chamber is thus burned out and as a result the treatment liquid, for example the treatment liquid, is simultaneously heated. washing and / or the units to be cleaned, for example the dishes. The air passed through is cooled, whereby the water vapor contained therein is totally or partially condensed. This is preferably done as a closed air circuit. The introduction of hot water vapor and heated air into the treatment chamber during a partial program stage with treatment liquid to be heated or under certain conditions already heated, is sufficient to a very large extent to sufficiently heat the treatment liquid. As a result, further additional heating can be largely eliminated and the heat energy used for desorption can be used almost entirely to heat the treatment liquid, for example the washing liquid and / or the parts to be cleaned, for example the dishes. With the exception of a small part of energy that is needed to overcome the bonding forces between water and reversibly dehydrating material. Furthermore, along with energy savings, an efficient cleaning of the parts to be treated for cleaning is also guaranteed.

The passage of air through is carried out during a stage of the partial program with treatment liquid to be heated.

In another embodiment, for the desorption of the reversibly desiccable material, air is passed through the sorclone column and burned and the air is led through a heat accumulator to cool it and then the air is led for heating. through the heat accumulator and is taken to the treatment chamber, to temporarily accumulate in the heat accumulator the heat used for desorption.

According to the invention, the sorclon column or the air in a pipe towards the sorclon column is heated by means of a heater for desorption.

According to another advantageous variant, it is heated by the heated air conveyed through the treatment liquid and / or the units to be treated and the moisture desorbed from the sorclon column is at least partially released into the treatment chamber.

ES 2 602 183 T3

Furthermore, in a stage of the partial program with treatment liquid to be heated, for example "rinsed", air can be led from the treatment chamber through the sorption column with the heater switched off and into the treatment chamber, being heated by the heat. condensation of the air in the sorption column.

The invention will now be described on the basis of an exemplary implementation of a method in a dishwasher.

The method according to the invention for operating an appliance with at least one drying partial program stage is carried out in the described execution program in a dishwasher. As is known, a dishwasher has a washing procedure whose program sequence generally consists of at least one "prewash" partial program stage, one "wash" partial program stage, at least one "intermediate rinse" partial program stage, a "rinse" partial program stage and a "dry" partial program stage. Within the framework of the invention, in the exemplary embodiment described, in the "drying" partial program stage, of which there is at least one, air is led from a treatment chamber through a sorption column and then with return preference to the treatment chamber.

In the exemplary embodiment, the treatment chamber of the dishwasher - the wash tub - is provided with an outlet in the upper zone of the wash tub. From this outlet an air pipe leads to a fan and from the fan to the sorption column.

This sorption column contains reversibly dehydrable material, which extracts moisture from the air during the passage through, then warms up and thereby also heats the air passed through. In addition to this heating effect, it is also possible to additionally heat the air with a heater.

In the exemplary embodiment, another air pipe leads from the sorption column to an outlet located in the lower zone of the wash basin.

The heated air passed into the wash basin is completely dry and has a high moisture absorption capacity. It rises upwards in the wash basin and absorbs the residual moisture from the parts to be treated, the parts to be washed. It is then conducted, as already described above, back to the sorption column.

By using reversibly dehydratable material, it is preferable not to heat the parts to be treated, for example in a dishwasher in the "rinse" partial program stage. This means considerable energy savings. By heating the air, it increases its moisture absorption capacity in each pass through the sorption column, which improves the drying result and shortens the drying time. In the preferably closed air system, an exchange of dirty air from the environment is completely excluded, thus preventing the units to be treated from being soiled again.

The reversibly dehydrable material has as known a limited liquid absorption capacity. In order to be able to use it again, a desorption is necessary, in which the reversibly dehydrable material is heated to a high temperature and the liquid then exits as vapor.

Within the framework of the invention, the reversibly dehydrable material is preferably desorbed during a partial program stage with treatment liquid to be heated.

In the exemplary embodiment, the reversibly dehydrable material is desorbed during a partial program stage "wash" and / or "pre-wash", in which the parts to be washed are subjected to treatment liquid - washing liquid - in a dishwasher. heated by spraying devices. To do this, a heater located, for example in the sorption column, is operated, which burns the reversibly dehydrable material to a high temperature.

Within the framework of the invention, during the desorption of the reversibly dehydratable material, air is led from a treatment chamber, for example with an outlet through a sorption column and then back to the treatment chamber, for example with an inlet, heating by means of a heater the air during the passage through.

In the exemplary embodiment, during a "wash" partial program stage, air is sucked from the wash tank by means of the aforementioned fan and is forced through the sorption column. The hot water vapor that comes out of the sorption column and the now heated air enters the washing tub through the aforementioned inlet and impinges there on the washing liquid that has circulated and / or the dishes.

The introduction of hot water vapor and hot air into the treatment chamber during a partial program stage with treatment liquid to be heated or, under certain circumstances, already heated, is sufficient to a very large extent to sufficiently heat the washing liquid and / or dishes. As a result, further additional heating can be largely eliminated and the energy used for desorption can be used almost entirely to heat the treatment liquid (wash liquid) and / or the dishes, except for a small part of the energy that is needed to overcome the bonding forces between water and reversibly dehydrable material. Besides energy saving, efficient cleaning of the parts to be treated is also guaranteed.

ES 2 602 183 T3

In another variant, the desorption of the material is reversibly dehydrated during a partial program stage with treatment liquid to be heated, but at any other moment in which the energy that remains free in the desorption is temporarily accumulated in a heat accumulator, for example with a medium that is liquefied with a high heat of fusion or a latent heat accumulator and is transferred when necessary to a treatment liquid to be heated and / or to the dishes. In this way, for example in the event that the amount of heat used for desorption is greater than that required in a partial program stage, this surplus energy can be used advantageously in a subsequent partial program stage with treatment liquid. to heat up.

The sorclone column is heated - as already described - preferably during a partial program stage with treatment liquid to be heated with a heater to a very high temperature, for example 300 ° C, so that the sorclone column yields absorbed water.

Also in the drying partial program stage, the sorclone column is heated at elevated temperatures, for example 150 ° - 200 ° C, by means of the heat of condensation of water vapor or humidity.

As a result, the dry air introduced into the wash tub or the air, steam, temperatures can reach that can damage the dishes, for example with plastic parts. The inlet temperature of the air in the washing chamber must therefore be lowered in another execution with such cooling that no damage results.

In the drying sub-program stage, waste water is conveyed to or around the inlet opening and the air flow is thereby cooled. In addition, the dry and hot air absorbs a part of the water, which, due to the cold of vaporization, causes the cooling of the air flow. In a partial program stage with treatment liquid to be heated, a heat exchange takes place by means of the injection water and the air flow with water vapor at the inlet opening. Advantageously, the inlet opening is positioned such that the air flow does not impinge directly on the dishes and the injection water provides sufficient cooling of the air flow.

In addition to the heater for heating the sorclon column - hereinafter referred to as air heating, a dishwasher corresponding to the invention has, in an embodiment not shown, a passage heater for the washing liquid, in the case that on the basis the present invention is not waived. IF in the partial program stage "rinse" a heating is necessary in another execution, this can be achieved either with the passage heater known from the state of the art or with the air heater with the fan connected. The advantage of heating with the air heater is that the heat energy accumulated in the sorclone column can be used for drying in the next "drying" sub-program stage.

In another variant, the fan can be switched on - with the air heating switched off - during the partial program stage with treatment liquid to be heated, for example in "rinse".

In this way, humid air is passed through the sorclone column, which absorbs the moisture and the sorclone column is heated by the condensation energy which is released and thus the air passed through is also heated. In this way, the condensation heat can be used to heat the washing liquid and / or the dishes. The sorclone column has to be designed in such a way that a good drying result is still achieved in the partial program stage "drying".

With the present invention a method is provided with which it is possible to operate apparatus of the type mentioned at the beginning as economically as possible, to efficiently dry the parts to be dried, as well as to keep the energy consumption that this implies as low as possible.