EP2352413B1 - 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.

From the DE 103 53 774 A1 , of the DE 103 53 775 A1 , of the WO-A-2005/053504 and the DE 10 2005 004 096 A1 Dishwashers with so-called Sorptionstrocknungssystemen for exothermic drying of cleaned items are known. Here, in a partial program step "drying" of the dishwasher of the dishwasher for drying items by a fan humid air from the serving as a washing compartment interior of the dishwasher is passed through a sorption and withdrawn through the sorbent located in the reversible dehydratable drying material moisture from the air passed. For regeneration, ie desorption of the drying material, the reversibly dehydratable drying material is heated to very high temperatures. Water stored in this drying material thereby emerges as hot water vapor and is conducted into the rinsing container by means of an air flow generated by means of the fan. As a result, liquid and / or a washware located in the washing container and the air in the washing container can be heated. Such a sorption drying system has proved to be very advantageous for energy-saving and quiet drying of the dishes.

The object of the invention is to achieve a further improved desorption result for the reversibly dehydratable drying material of the sorption drying apparatus.

The invention is based on a method for operating a dishwasher, in particular a domestic dishwasher, with a sorption drying system in which a desorption process of a reversibly dehydratable dry material, in particular zeolite, is effected at least temporarily.

According to the invention, it is provided that parameters influencing the desorption process are evaluated for determining the time for carrying out the desorption. This allows for an adapted selection of the time at which the Desorption should take place to ensure efficient desorption, since it is ensured that the desorption process is carried out when the temperature of the air in the interior of the dishwasher is relatively low and thus the moisture absorption capacity of the air is greatest.

In a further development, it is provided that the air temperature in the dishwasher and / or the water inlet temperature are detected as parameters. Thus, only the air temperature alone or the water inlet temperature alone or both temperatures can be evaluated together. The air temperature in the dishwasher depends on room temperature in the vicinity of the dishwasher. However, the air temperature can also deviate greatly from the room temperature, if shortly before a Spülprogrammlauf took place without it could come to a cooling of the dishwasher. If only the air temperature or water inlet temperature is detected, the determination of the time for performing the desorption can be made on the basis of stored values, e.g. in tabular form. In this case, the water supply temperature, the extent of cooling by a refilling with liquid, in particular with water from a home-side supply system, set. If, on the other hand, both the air and the water inlet temperature are detected, a comparison with stored values can also be made and / or the difference of the two temperatures is evaluated and the time of desorption is determined. The difference between these two temperature values is therefore a measure for determining how strong the temperature in the interior of the dishwasher will fall below the starting temperature. As an alternative to detecting the air temperature, the detection of the room temperature can also be provided alone or together with the water inlet temperature at the installation site of the dishwasher.

In a further development it is provided that a desorption process is carried out at least partially during a first program step, while the heating means of the dishwasher are operated when the air temperature is higher than the water supply temperature by a predetermined temperature value at the most. In this case, the heating means may be an air heater, can be erwakbar with the air, which is driven by the drying material. In this case, no excessive cooling is to be expected by refilling with liquid, so that a Desortionsvorgang is performed in the first program step in which a heating of liquid takes place, such as the program step cleaning or the program step prewash, if a particularly intensive cleaning is desired.

In a further development, it is provided that a desorption process is carried out at least partially during a program step in which heating means are operated after an at least partial liquid change when the air temperature is higher than the water inlet temperature at least by a predetermined temperature value. In this case, a significant cooling is to be expected by refilling with liquid, so that a Desortionsvorgang is carried out at the later program step, before a refilling is carried out as part of a fluid change. It can be e.g. to the program step cleaning or the program step rinse clear

In a further development it is provided that the predetermined temperature value is selected substantially between 3 to 30 ° C, in particular between 5 and 15 ° C. This ensures that only in the case of large temperature differences does the time of the desorption process be postponed, in which due to the high starting temperature no complete and efficient desorption is to be expected.

In a further development, it is provided that the desorption process is carried out at least partially during a program step cleaning with detergent addition and cleaning action. This allows a particularly energy-efficient cleaning of items to be washed.

In a further development, it is provided that the desorption process is carried out at least partially during a program step of pre-rinsing with cleaning action without addition of detergent. As a result of the associated heating, the cleaning effect during the program step of pre-rinsing and thus of the rinsing program can be increased.

In a further development it is provided that the desorption process is carried out at least partially during a program step rinsing with rinse aid addition. By the associated heating, the drying effect during the subsequent program step drying can be increased or the duration of the program step drying can be reduced.

In a further development, it is provided that a quantity of liquid, in particular a quantity of fresh water from a house-side water supply system, is temporarily stored in a water tank which is in heat-conducting contact with the surroundings of the dishwasher. The water tank is at the end of a Rinsing program run filled, so that in the meantime, until the next start of a Spülprogrammdurchlaufs cached in the water tank amount of water from the inlet water temperature of eg 15 ° C can warm to room temperature. This liquid heated to room temperature is used in a rinse cycle to perform the rinse program step of pre-rinse. A renewed filling with water from the water supply system causes a corresponding cooling below the room temperature.

Furthermore, the object of the invention is achieved by a dishwasher, in particular a domestic dishwasher, which is designed to at least one program step of a plurality of program steps at least partially to effect a desorption of a reversibly dehydratable dry material, in particular zeolite, a Sorptionstrocknungssystem, provided according to the invention in that detection means are provided for detecting environmental parameters at the location of the dishwasher and evaluation means for determining the time for performing the desorption.

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 is arranged in a floor assembly BO below the interior IR of the dishwasher GS next to other components of the dishwasher. In operation, i. 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 Sorptionstrockungssystem, with the arranged in the baskets GR and cleaned items at the end of a Rinse program run can be dried. 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 reversibly dehydratable drying material, e.g. 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, an amount of liquid is 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 can from the Program steps pre-rinse V, cleaning R, intermediate rinsing Z, rinsing K and drying T exist, 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 is heated in the dishwasher GS by means of heating until a predetermined maximum temperature is reached and a subsequent Nachwaschphase together, while the heater is turned off, the slowly cooling liquid by the circulating pump UP is circulated. 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, the fluid circulated by the circulation pump UP first passes through during a first phase P1 heated air heater HZ in the sorption SB to a maximum temperature T1, wherein at the same time the fan LT generates a circulating through the interior IR of the dishwasher GS air flow. 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 can be reliably and completely desorbed by the circulation of relatively cold and dry air from the interior IR dishwasher GS , 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, in order thus to ensure that due to the heating power of the air heater HZ there is no excessive heating of the blow-out opening HZ with overheating damage.

For this purpose, during operation of the air heater HZ, ie, for example, during the phase P1, the circulation pump UP is operated so that liquid is conveyed by the circulation pump from the pump sump PS through the supply line to the spray arm SA. 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, during operation no air bubbles 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 Abtropfphase AB, ie at the end of the program step rinse K, a Abpumpvorgang takes place, in which the liquid mixed with rinse aid is conveyed by the drain pump LP through the drain line EL in a house-side sanitation 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 another 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 wastewater 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 For this purpose, by means of the air heater HZ liquid is heated starting from a start temperature T0 during a phase P1 'to a temperature T1' in which as described above by means of the fan LT by a 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 another phase P5 further heating of the liquid to a Temperature T5 done to improve drying with the sorption drying system.

LIST OF REFERENCE NUMBERS

FROM

dripping

AU

Ausblassöffnung

BO

bottom assembly

EGG

inlet

EL

disposal line

GK

dish rack

GS

dishwasher

HZ

air heating

IR

inner space

LK

air duct

LP

Drain pump

LT

Fan

N / A

post-wash

P1 '

Phase 1 '

P1

Phase 1

P2

Phase 2

P3

Phase 3

P4

Phase 4

P5

Phase 5

PS

sump

SA

spray arm

SB

sorption

t1

Nachfüllzeitpunkt

T0

starting temperature

T1 '

temperature

T1

temperature

T2

temperature

T3

temperature

T4

temperature

T5

temperature

UP

circulating pump

WZ

water Heating

ZEO

drying material

ZL

feed

Claims (20)

1. Method of operating a dishwasher (GS), particularly a domestic dishwasher, in which a desorption process of a reversibly dehyrdratable drying material (ZEO), particularly zeolite, of a sorption drying system is carried out at least at intervals, characterised in that parameters influencing the desorption process are evaluated for determination of the instant in time for performance of the desorption.
2. Method according to claim 1, characterised in that the air temperature in the dishwasher (GS) and/or the water feed temperature is or are detected as parameter.
3. Method according to claim 2, characterised in that a desorption process is performed at least partly during a first program step (V, R), while the heating means of the dishwasher (GS) are operated, of a plurality of program steps (V, R, Z, K, T), when the air temperature is higher than the water feed temperature by at most a predetermined temperature value.
4. Method according to claim 2 or 3, characterised in that a desorption process is performed at least partly during a program step (R, K) of a plurality of program steps (V, R, Z, K, T), during which heating means of the dishwasher (GS) are operated, when the air temperature is higher than the water feed temperature at least by a predetermined temperature value.
5. Method according to claim 3 or 4, characterised in that the predetermined temperature value is selected to be substantially between 3 to 30° C, particularly between 5 and 15° C.
6. Method according to at least one of claims 3 to 5, characterised in that the desorption process is performed at least partly during a program step of cleaning (R) with feed of cleaner and cleaning action.
7. Method according to at least one of claims 3 to 6, characterised in that the desorption process is performed at least partly during a program step of pre-rinsing (V) with cleaning action without feed of cleaner.
8. Method according to at least one of claim 3 to 7, characterised in that the desorption process is performed at least partly during a program step of clear-rinsing (K) with feed of clear-rinsing agent.
9. Method according to at least one of claims 1 to 9, characterised in that a quantity of liquid, particularly a quantity of fresh water, from a domestic water supply system is intermediately stored in a water tank disposed in thermally conductive contact with the environment of the dishwasher (GS).
10. Method according to at least one of claims 1 to 10, characterised in that heating means (HZ) constructed as an air heater are used.
11. Dishwasher (GS), particularly domestic dishwasher, with a sorption drying system which is constructed to carry out a desorption process of a reversibly dehydratable drying material (ZEO) particularly zeolite, at least at intervals, characterised in that detecting means for detection of parameters influencing the desorption process and evaluating means for determining, on the basis of the parameters, the instant in time for performance of the desorption are provided.
12. Dishwasher (GS) according to claim 11, characterised in that the detecting means are constructed for detecting the air temperature in the dishwasher (GS) and the water feed temperature.
13. Dishwasher (GS) according to claim 11 or 12, characterised in that the evaluating means are so arranged that a desorption process is performed at least partly in a first program step (V, R) of a plurality of program steps (V, R, Z, K, T), during which heating means (HZ) of the dishwasher (GS) are operated, when the air temperature is higher than the water feed temperature by at most a predetermined temperature value.
14. Dishwasher (GS) according to claim 12 or 13, characterised in that the evaluating means is so arranged that a desorption process is performed at least partly in a program step (R, K) of a plurality of program steps (V, R, Z, K, T), in which heating means (HZ) of the dishwasher (GS) are operated, when the air temperature is higher than the water feed temperature by at least a predetermined temperature value.
15. Dishwasher (GS) according to claim 13 or 14, characterised in that the predetermined temperature is selected to be substantially between 3 to 30° C, particularly between 5 and 15° C.
16. Dishwasher (GS) according to at least one of claims 13 to 15, characterised in that the desorption process is performable at least partly during a program step of cleaning (R) with feed of cleaner and cleaning action.
17. Dishwasher (GS) according to at least one of claims 13 to 16, characterised in that the desorption process is performable at least partly during a program step of pre-rinsing (V) with cleaning action without feed of cleaner.
18. Dishwasher (GS) according to at least one of claims 13 to 17, characterised in that the desorption process is performable at least partly during a program step of clear-rinsing (K) with feed of clear-rinsing agent.
19. Dishwasher (GS) according to at least one of claims 13 to 18, characterised by a water tank, which is disposed in thermally conductive contact with the environment of the dishwasher, for intermediate storage of a quantity of liquid, particularly a quantity of fresh water, from a domestic water supply system.
20. Dishwasher (GS) according to at least one of claims 11 to 19, characterised in that the heating means (HZ) is constructed as an air heater.

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