EP2352414B1 - Method for operating a dishwasher - Google Patents

Description

The invention relates to a method for operating a dishwasher, in particular a domestic dishwasher according to the preamble of patent claim 1.

Dishwashers are known to go through wash programs comprising a plurality of program steps, such as e.g. Pre-rinsing, cleaning, rinsing, rinsing and drying the cleaned items. In this case, in the program step rinsing, the cleaned items to be washed are treated with a liquid, in particular with a liquid added with a rinse aid, and then dried in the program step of drying.

The document EP-A1-1674031 discloses a dishwasher and a method for operating a dishwasher, in particular a domestic dishwasher, in which at least in a program step rinsing cleaned Spulgut with a liquid, in particular with a liquid added with a rinse aid, is applied, and then drying in a program step drying the Spulgutes takes place, wherein prior to the beginning of the program step drying a dripping phase is passed, at the beginning of the loading of the liquid is terminated and the liquid drains from the Spulgut.

The invention has for its object to achieve a further improved drying result.

The invention is based on a method for operating a dishwasher, in particular a domestic dishwasher, in which at least in one program step rinsing cleaned items to be treated with a liquid, and then in a program step drying a drying of the items.

In addition, it is provided that before the start of the program step drying a dripping phase is passed through, at the beginning of the loading of items to be washed with the liquid is stopped and the liquid drains from the dishes. In this way, the drying performance can be increased or the duration of the program step drying can be reduced in a surprisingly simple manner and at the same time the amount of liquid stored in the desiccant of the sorption drying system can be reduced. This in turn shortens the duration of the desorption process.

According to one embodiment, it is provided that the dripping phase essentially takes between 3 and 15 minutes, in particular between 5 and 10 minutes. This allows to increase the drying performance without extending the total duration of a wash program.

For this purpose, it is provided according to the invention that during the program step rinsing by means of a circulation pump, the items to be washed are loaded with the rinse aid mixed liquid, wherein at the end of the program step rinsing the circulation pump is stopped.

In a further development, it is provided that a forced flow of the items to be dried is carried out during the program step dry. This further improves the drying result and at the same time shortens the duration of the program step drying.

For this purpose, according to a development, the forced flow is generated by means of a fan.

For this purpose, it is provided according to a development that during the program step drying the fan for a predetermined period of time, is operated substantially between 1 and 60 minutes, in particular between 3 and 30 minutes.

Furthermore, according to the invention, it is provided that, after stopping the circulating pump, an evacuation process, in particular by means of a lye pump, is carried out. As a result, the drying performance can be further increased since the liquid expired from the items to be washed is conveyed out of the dishwasher.

For this purpose, it is provided according to a development that essentially an amount between 1 and 5 liters, in particular between 2 and 4 liters, is pumped out.

In a further development, it is provided that at the end of the program step drying a pumping down, in particular by means of a lye pump, is performed. As a result, residual liquid residues are conveyed out of the dishwasher.

For this purpose, it is provided according to a development that substantially between 0.05 and 1 liter, in particular between 0.1 and 0.3 liters, are pumped.

In a further development it is provided that for drying the ware moist Air from an interior of the dishwasher is passed through a sorption drying system. This allows a particularly energy-efficient drying of cleaned items.

In a further development, it is provided that a reversibly dehydratable drying agent, in particular zeolite, is used for the exothermic drying. This material is characterized by a high water absorption capacity and good reversible dehydratability, wherein the drying line can be increased again without additional expenditure of energy by the exothermic drying.

Furthermore, the object of the invention is achieved by a dishwasher, in particular domestic dishwasher, which is at least designed to apply a liquid to at least one program step rinsing cleaned items to be washed and then drying the items to be dried in a program step, wherein it is provided that before the beginning of the program step drying a dripping phase is provided at the beginning of the loading of items to be washed with the liquid is completed and the liquid drains from the dishes. The dishwasher is characterized in that a circulation pump for applying items to be washed with liquid is provided at least during the program step rinsing, the dishwasher for stopping the circulation pump at the end of the program step rinsing is formed, and that after stopping the circulation pump, a pumping down, in particular by means of a lye pump, is feasible

Further developments of the dishwasher according to the invention are specified in the subclaims.

The invention and its development will be explained in more detail with reference to drawings.

Fig. 1

eine schematische Darstellung eines Ausführungsbeispiels einer erfindungsgemäßen Geschirrspülmaschine mit einem Sorptionstrocknungssystem,

Fig. 2

eine schematische Darstellung des Temperaturverlaufs während eines ersten Ausführungsbeispiels eines erfindungsgemäßen Spülprogrammdurchlaufs,

Fig. 3

eine schematische Darstellung des Temperaturverlaufs eines weiteren, zweiten Ausführungsbeispiels eines erfindungsgemäßen Spülprogrammdurchlaufs, und

Fig. 4

eine schematische Darstellung des Temperaturverlaufs eines weiteren, dritten Ausführungsbeispiels eines erfindungsgemäßen Spülprogrammdurchlaufs.

Show it:

Fig. 1

a schematic representation of an embodiment of a dishwasher according to the invention with a Sorptionstrocknungssystem,

Fig. 2

a schematic representation of the temperature profile during a first embodiment of a Spülprogrammdurchlaufs invention,

Fig. 3

a schematic representation of the temperature profile of a further, second embodiment of a Spülprogrammdurchlaufs invention, and

Fig. 4

a schematic representation of the temperature profile of another, third embodiment of a Spülprogrammdurchlaufs invention.

It is going on first FIG. 1 Referenced.

A dishwasher GS designed in the present exemplary embodiment as a domestic dishwasher has an interior space IR serving as a washing container, which can be opened or closed for loading and unloading by means of a door (not shown) pivotably hinged to the dishwasher GS. Dishwashing baskets GK are provided in the interior IR of the dishwasher GS for receiving items to be cleaned, which can be pulled out of the interior IR of the dishwasher GS in order to facilitate loading and unloading.

In order to clean the items to be stored in the crockery baskets GK, means for supplying items to be washed with liquid are provided in the interior IR of the dishwasher GS as spraying arms SA, wherein the liquid may, for example, be filled with water. can act with detergents or with rinse aid added water, so as to effect a cleaning effect or streak-free drying. The liquid flowing down from the items to be washed collects in a pump sump PS, which is arranged in the bottom area of the interior IR of the dishwasher GS.

The spray arms SA are fluidly connected via a supply line ZL with a circulation pump UP, which in addition to other components of the dishwasher GS is disposed in a floor assembly BO below the interior IR of the dishwasher GS. During operation, ie when the circulation pump UP is running, the circulation pump UP sucks the liquid accumulated in the pump sump PS and delivers it through the supply line ZL to the spray arms SA. In order to heat the liquid circulated by the operation of the circulating pump UP, the circulating pump has an integrated water heater WZ for heating the liquid. Alternatively, in addition to the circulation pump UP, a separate instantaneous water heater or another water heater may be provided. For emptying the interior IR of the dishwasher GS, a drain pump LP is provided, which is also in fluid-conducting connection with the pump sump PS and can be connected to a disposal line EL to a house-side sewage disposal network.

Furthermore, the dishwasher GS has a sorption drying system, with which in the dish racks GR arranged and cleaned items can be dried at the end of a Spülprogrammdurchlaufs. For this purpose, a sorption SB is provided in the bottom assembly BO, which is air-conductively connected to an inlet EI via an air channel LK, wherein a fan LT is provided for generating a forced flow. In order to recirculate the air sucked in through the inlet EI and conveyed by the ventilator LT into the sorption container back into the interior IR of the dishwasher GS, an outlet opening AU is provided in the bottom area of the interior IR dishwasher GS.

In order to effect a drying of cleaned items to be washed, air is sucked in from the interior IR of the dishwasher GS by the fan LT, passed through the sorption container SB and again through the discharge opening AU back into the interior IR of the dishwasher GS. In order to dry the circulated air in this case, a drying agent for carrying out an exothermic drying is provided in the sorption container SB. It is a reversible dehydratable drying material, such as zeolite, which absorbs water due to its hydroscopic property, at the same time heat energy is released. By this released heat energy heating of the circulating air is effected, which at the same time increases the moisture absorption capacity of the circulating air. At the end of a drying process is an amount of liquid, stored in the drying material ZEO.

In order to restore the capacity of the drying agent ZEO for a new wash program run, an air heater HZ is provided, which is arranged in the present embodiment in the sorption SB. However, it is also possible to arrange an air heater outside the sorbent tank SB, e.g. in the air passage LK to cause heating of the conveyed into the sorbent SB air. In order to expel the amount of liquid stored in the drying material ZEO, an air flow generated by the fan LT is heated, so that the drying material ZEO can be heated to temperatures at which the amount of water stored in the drying material ZEO can be released again.

It will now be added to the FIGS. 2 to 4 Referenced.

Dishwashers GS continuous for cleaning and drying of items to be cleaned, wash programs, which consist of a plurality of program steps, which are passed through successively. Such a program may consist of the program steps pre-wash V, cleaning R, intermediate rinsing Z, rinsing K and drying T, with individual program steps such. B. the pre-wash V or intermediate rinse Z can also be hidden, while it is also conceivable to pass through individual program steps repeatedly, such as the intermediate rinsing Z. During the pre-rinsing V, for example, ware is charged with water without the addition of detergents, this either with unheated water or with heated water by means of a heater. For this purpose, water can be used that has been stored in a water tank (not shown). Such a water tank can be in heat-conducting connection with the environment of the dishwasher, so that liquid stored in the water tank, such as water from a home-side supply system, can warm up to room temperature. In the cleaning step R, cleaning of items to be washed takes place by application of detergent-added water, ie during the cleaning stage a detergent addition takes place. Furthermore, a heating of the liquid, so as to increase the cleaning effect of the cleaning agent. In this case, the cleaning step R is composed of a heating phase P1, P2, in which the liquid in the Dishwasher GS is heated by means of heating means until a predetermined maximum temperature is reached and a subsequent Nachwaschphase together, while the switched off heating means, the slowly cooling liquid is circulated by means of the circulation pump UP. In the intermediate rinse Z program step, liquid is applied to the items to be washed in order to convey dirt residues from the dishwasher GS. The next step in the program is rinsing K in preparation for the program step drying T, in which water mixed with rinse aid is circulated by means of the circulation pump and applied to the now cleaned items via the spray arms SA. Finally, the program step drying T, in which the ware is no longer charged with liquid, but by operation of the fan LT through the interior IR of the dishwasher GS and the sorbent SB circulating air flow is generated. A complete or at least partial fluid change can be carried out between the individual program steps, ie the dishwasher GS is emptied by means of the drain pump LP and the disposal line EL and refilled again by a supply line (not shown) making a connection to a house-side supply system.

In the rinse program according to FIG. 2 takes place only in the program step cleaning R heating of liquid. In this case, starting from a starting temperature T0, during a first phase P1, the liquid circulated by the circulation pump UP is heated by the air heater HZ in the sorption tank SB to a maximum temperature T1, wherein the fan LT at the same time circulates through the interior IR of the dishwasher GS air flow generated. The air heater HZ heats the drying material ZEO into the sorption container SB to temperatures at which the amount of water stored in the drying material ZEO is expelled from the drying material ZEO and conveyed through the outlet opening AU into the interior IR dishwasher GS. Due to the effect of the air heater HZ this amount of liquid is heated and thus causes by mixing the already circulated with the circulation pump UP liquid heating of the total amount of liquid in the interior IR dishwasher GS. Characterized in that by means of the air heater HZ during the program step cleaning R heating up to the first temperature T1, it is ensured that the dry material ZEO by the circulation Of relatively cold and dry air from the interior IR dishwasher GS can be reliably and completely desorbed. Instead of a rigid rinsing program sequence in which a desorption process is carried out in a first program section, in which a heating of liquid takes place, it can also be provided in an alternative embodiment to evaluate the parameters influencing the desorption process for determining the time for performing the desorption. This can be the air temperature and the water inlet temperature. For example, a desorption process in a program step cleaning or rinsing or, if appropriate, during the program step pre-rinse done.

During desorbing by means of the air heater HZ, the blow-out opening AU is cooled in the interior IR dishwasher GS, so as to ensure that due to the heating power of the air heater HZ no excessive heating of the blow-out opening HZ with overheating damage occurs.

For this purpose, during operation of the air heater HZ, i. e.g. during the phase P1, the circulation pump UP is operated so that liquid is conveyed from the pump sump PS through the supply line to the spray arm SA by the circulation pump. As a result, the spray arms SA are set in rotation and cause by spraying the exhaust opening AU, in particular a cap covering the exhaust opening AU with liquid, a cooling thereof.

In a next phase P2 of the program step cleaning R, the amount of liquid is heated from the first temperature T1 to the second temperature T2 by means of the water heater WZ.

In order to increase the cleaning effect during the program step cleaning R, it is provided by increasing the rotational speed of the circulation pump UP to increase the spray pressure of the water jets emerging from the spray arm SA. For this purpose, during the program step cleaning R during the Nachwaschphase NA, the volume of liquid circulated by means of the circulation pump UP is increased by a refilling step, for example. At time t1 (see. FIG. 2 ) and then increases the speed of the circulation pump UP, for example continuously, until the circulation pump again runs under runout condition, ie, no air bubbles during operation sucks, which reduces the flow rate of the circulation pump UP and leads to an undesirable noise. This makes it possible to take into account the amount of liquid released during the desorbing, which was stored in the drying material ZEO, in the dimensioning of the amount of liquid to be replenished and thus to reduce the total water requirement with improved cleaning performance.

Between the program step rinsing K and the program step drying T a dripping AB is provided (see. FIG. 2 ), while the liquid adhering to the cleaned items to be washed, ie, water added with rinse aid, can run off the items to be washed due to gravity and can collect in the pump sump PS of the interior IR of the dishwasher GS. As a result, the amount of liquid to be absorbed by the sorption drying system is reduced and thus the duration of the program step drying T.

Before this dripping phase AB, i. at the end of the program step rinsing K, a pumping down process takes place in which the liquid mixed with rinse aid is conveyed by means of the drain pump LP through the discharge line EL into a house-side wastewater disposal system. This is followed by the Abtropfphase AB, during which neither the circulation pump UP nor the drain pump LP and not the fan LT or one of the heaters HZ, WZ are in operation. After expiration of this dripping AB, the program step drying T starts by putting the fan LT, so that a circulating through the interior IR of the dishwasher and the sorbent SB air flow is generated to dry the cleaned items in the baskets GK. At the end of the program step drying T, a further pumping down by means of the drain pump LP, by means of which a remaining amount of liquid from the dishwasher GS is conveyed through the discharge line EL in a house-side sewage disposal system. Alternatively, it can also be provided to perform a further pump-down process additionally or alternatively at the beginning of the program step drying T.

In the washing program according to FIG. 3 and 4 A heating of liquid takes place in the first of the program steps, the program step prewash V. For this purpose, by means of the air heater HZ liquid starting from a start temperature T0 during a phase P1 'heated to a temperature T1', in which as described above by means of the fan LT through the interior IR of the dishwasher GS and the sorbent SB circulating air flow is generated. After reaching the temperature T1 ', the air heater HZ is deactivated. At this time, the drying material ZEO is not completely desorbed, ie in the drying material ZEO a residual amount of water is stored. To expel this amount of residual water from the drying material ZEO and thus have a again fully water-absorbent drying material ZEO at the beginning of the program step drying T available, in the subsequent program step cleaning R first heated the liquid by means of the air heater HZ to a temperature T1 and then by operating the Water heating to the temperature T2 heated. That is, the desorption phase of the drying agent ZEO in the sorption container SB is divided into two parts in this embodiment and is distributed over two program steps, namely the program step pre-wash V and the program step cleaning R.

In order to increase the cleaning effect by further increasing the temperature, another phase P3 (cf. FIG. 3 ), while the water heating WZ is used to further heat the liquid to a temperature T3.

In order to improve the drying result at the end of the program step drying T, in the embodiments according to FIGS Figures 3 and 4 provided that during the rinse step K, a heating of the liquid takes place. For this purpose, during a phase P4 by means of the water heater WZ liquid, which is water or water mixed with rinse aid, is heated to a temperature T4. Alternatively, for this purpose, instead of the water heating and the air heater HZ be used to complete, for example, a previously not complete in the course of the program desorption. In addition, during a further phase P5, a further heating of the liquid to a temperature T5 can take place in order to improve the drying with the sorption drying system.

Claims (20)

1. Method for operating a dishwasher (GS), in particular a household dishwasher, wherein at least in a final rinse (K) program step a fluid, in particular a fluid containing rinse aid, is applied to cleaned items being washed and then in a drying (T) program step the items being washed are dried, with the start of the drying (T) program step being preceded by a drip-off phase (AB), at the start of which fluid ceases to be applied and the fluid drains off the items being washed, characterised in that during the final rinse (K) program step fluid is applied to the items being washed by means of a circulating pump (UP), with the circulating pump (UP) being stopped at the end of the final rinse (K) program step and a drain operation, in particular by means of a drain pump (LP), being performed after the circulating pump (UP) has stopped.
2. Method according to claim 1, characterised in that the drip-off phase (AB) lasts essentially between 3 and 15 minutes, in particular between 5 and 10 minutes.
3. Method according to at least one of claims 1 and 2, characterised in that the items to be dried are subjected to a forced flow during the drying (T) program step.
4. Method according to claim 3, characterised in that the forced flow is generated by means of a fan (LT).
5. Method according to claim 4, characterised in that during the drying (T) program step the fan (LT) is operated for a predetermined duration, essentially between 1 and 60 minutes, in particular between 3 and 30 minutes.
6. Method according to one of claims 1 to 5, characterised in that essentially a quantity between 1 and 5 litres of fluid, in particular between 2 and 4 litres of fluid, is drained.
7. Method according to at least one of claims 1 to 6, characterised in that a drain operation, in particular by means of a drain pump (LP), is performed at the end of the drying (T) program step.
8. Method according to one of claims 1 to 5, characterised in that essentially between 0.05 and 1 litre of fluid, in particular between 0.1 and 0.3 litres of fluid, is drained.
9. Method according to at least one of claims 1 to 8, characterised in that moist air from an interior compartment (IR) of the dishwasher (GS) is conducted through a sorption drying system to dry the items being washed.
10. Method according to claim 9, characterised in that a reversibly dehydratable drying agent (ZEO), in particular zeolite, is used for exothermic drying.
11. Dishwasher (GS), in particular a household dishwasher, at least configured to apply a fluid, in particular a fluid containing rinse aid, to cleaned items being washed in at least one final rinse (K) program step and then in a drying (T) program step to dry the items being washed, with the start of the drying (T) program step being preceded by a drip-off phase (AB), at the start of which the application of fluid ceases and the fluid drains off the items being washed, characterised in that a circulating pump (UP) is provided to apply fluid to items being washed at least during the final rinse (K) program step, the dishwasher (GS) being configured to stop the circulating pump (UP) at the end of the final rinse (K) program step and a drain operation, in particular by means of a drain pump (LP), being able to be performed after the circulating pump (UP) has stopped.
12. Dishwasher (GS) according to claim 11, characterised in that the drip-off phase (AB) has a duration of essentially between 3 and 15 minutes, in particular between 5 and 10 minutes.
13. Dishwasher (GS) according to at least one of claims 11 and 12, characterised in that means for applying a forced flow to the items to be dried are provided at least during the drying (T) program step.
14. Dishwasher (GS) according to claim 13, characterised in that the means for applying a forced flow comprise a fan (LT).
15. Dishwasher (GS) according to claim 14, characterised in that during the drying (T) program step the fan (LT) can be operated for a predetermined duration, essentially between 1 and 60 minutes, in particular between 3 and 30 minutes.
16. Dishwasher (GS) according to at least one of claims 11 to 15, characterised in that essentially a quantity between 1 and 5 litres of fluid, in particular between 2 and 4 litres of fluid, can be drained.
17. Dishwasher (GS) according to at least one of claims 11 to 16, characterised in that a drain operation, in particular by means of a drain pump (LP), can be performed at the end of the drying (T) program step.
18. Dishwasher (GS) according to claim 17, characterised in that essentially between 0.05 and 1 litre of fluid, in particular between 0.1 and 0.3 litres of fluid, can be drained.
19. Dishwasher (GS) according to claim 18, characterised in that a sorption drying system is provided to dry the items being washed, through which moist air from an interior compartment (IR) of the dishwasher can be conducted.
20. Dishwasher (GS) according to claim 19, characterised in that the sorption drying system has at least one reversibly dehydratable drying agent (ZEO), in particular zeolite.

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