EP2352412A2

EP2352412A2 - Method for operating a dishwasher

Info

Publication number: EP2352412A2
Application number: EP09736942A
Authority: EP
Inventors: Michael Fauth; Helmut Jerg; Kai Paintner; Andreas Reiter; Roland Rieger
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2008-11-07
Filing date: 2009-10-16
Publication date: 2011-08-10
Also published as: DE102008043573A1; WO2010052118A3; WO2010052118A2

Abstract

The invention relates to a method for operating a dishwasher, especially a household dishwasher, according to which a plurality of program steps (V, R, Z, K, T) are carried out. During at least one of the program steps (V, R, Z), liquid is heated to a maximum temperature (T1', T2, T3'), and during another clear-rinsing (K) program step, the liquid reaches a maximum clear rinsing temperature (T4, T5). According to the invention, during at least one of the program steps (V, R, Z), liquid is heated to a maximum temperature (T1', T2, T3') that is essentially the same as, or higher than, the maximum clear rinsing temperature (T4, T5).

Description

Method for operating a dishwasher

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. During some of the program steps, e.g. cleaning or rinsing, liquid e.g. heated with a heater designed as a water heater. In this case, during the program step cleaning by heating liquid, the cleaning performance should be increased, while the program step rinse by the application of heated liquid, such as. with rinse aid added water, the drying of cleaned items to be improved or accelerated in the subsequent program step drying.

The invention has for its object to reduce the energy consumption with constant cleaning and drying results.

The invention is based on a method for operating a dishwasher, in particular a domestic dishwasher, in which a plurality of program steps are passed, of which at least one program step liquid is heated to a maximum temperature, and in a further program step rinse liquid a maximum Rinse temperature reached.

According to the invention, during at least one of the program steps, liquid is heated to a maximum temperature that is substantially equal to or higher than the maximum rinse temperature. This allows for a particularly energy-efficient cleaning of items to be washed, at the same time the items to be washed by the low

Temperature differences is exposed to low thermal loads and thus is particularly gentle. In this case, a substantially identical temperature is understood to mean that the temperatures are, for example, due to manufacturing tolerances and / or natural deviations slightly differ during operation, eg around 5 to 10 ⁰ C.

In a further development, it is provided that during at least one program step cleaning the maximum temperature is higher than the maximum rinse temperature on the

Liquid is heated in the program step rinsing. In doing so, e.g. due to particularly high temperatures in the cleaning program step compared to the program step

Rinse a particular high cleaning performance achieved because an optimum temperature is achieved in which in the program step cleaning added detergents to maximize their effect, the energy required for rinsing is reduced.

In this case, a further development is provided that during at least one program step cleaning the maximum temperature is substantially between 5 and 50 ⁰ C, in particular between 10 and 30 ⁰ C higher than the maximum rinse temperature is heated to the liquid in the program step rinse.

In a further development, it is provided that during at least one program step pre-rinse the maximum temperature is higher than the maximum rinse temperature, is heated to the liquid in the program step rinse. This allows the cleaning result to be further improved, since the elevated liquid temperature allows the removal line to be further increased during the program step of pre-rinsing without the addition of detergent.

In this case, a further development is provided that during at least one program step pre-rinsing the maximum temperature is substantially between 1 and 20 ° C, in particular between 5 and 10 ⁰ C higher than the maximum rinse temperature is heated to the liquid in the program step rinse.

In a further development it is provided that during at least one program step intermediate rinsing the maximum temperature is higher than the maximum rinse temperature, is heated to the liquid in the program step rinse. This allows a particularly energy-efficient operation of a dishwasher.

In this case, a development is provided that during at least one program step intermediate rinsing the maximum temperature substantially between 1 and 20 ⁰ C, especially between 5 and 10 ⁰ C higher than the maximum rinse temperature is heated to the liquid in the program step rinse.

In a further development it is provided that at least temporarily during one of the program steps during which liquid is heated, a desorption of a reversible, dehydratable drying material, in particular zeolite, is performed.

This allows a particularly energy-efficient operation using a

Sorption drying system, during during a drying process in

Drying material stored moisture is then expelled again by introducing heat energy, wherein the expended for expelling thermal energy is also used for heating of items to be washed and / or liquid.

In this case, a development is provided that at least temporarily during a further program step drying moisture of the moist air is absorbed by a reversible, dehydratable drying material, in particular zeolite. This allows a particularly energy-efficient drying of cleaned items, since no or only a slight heating of liquid in the program step rinse is required to obtain an optimal cleaning result.

It is provided in a development that, during a program step, drying of items to be washed by passing moist air from an interior of the dishwasher is dried by a sorption drying system.

In a development it is provided that liquid stored in a water tank of the dishwasher is used in at least one of the program steps. Such a water tank can with the environment of the dishwasher in heat-conducting

Be connected, so that in the water tank cached liquid, such.

Water from a home-based supply system, can warm to room temperature. If the liquid stored in the water tank is e.g. In a pre-rinse program step, this increases the cleaning effect and reduces the overall energy requirement again.

Furthermore, the object of the invention is achieved by a dishwasher, in particular domestic dishwasher, with heating means for at least temporarily heating liquid to a maximum temperature during a program step of a plurality of program steps, and designed to carry out another Program step rinsing, wherein the liquid reaches a maximum rinse temperature, wherein according to the invention that during at least one of the program steps liquid has a maximum temperature which is higher than the maximum rinse temperature.

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.

Show it:

1 is a schematic representation of an embodiment of a dishwasher according to the invention with a sorption drying system,

FIG. 2 shows a schematic representation of the temperature profile during a first embodiment of a rinsing program run according to the invention, FIG.

Fig. 3 is a schematic representation of the temperature profile of another, second

Embodiment of a Spülprogrammdurchlaufs invention, and

4 is a schematic representation of the temperature profile of a further, third exemplary embodiment of a rinsing program run according to the invention.

Reference is first made to FIG.

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. In the interior IR of the dishwasher GS are baskets GK for receiving too cleaning items provided which can be pulled out of the interior IR of the dishwasher GS 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. With

Cleaning agents or rinse with water may act to offset such a

To effect 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, among other components 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 which arranged in the baskets GR 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 via an air duct LK with an inlet El, wherein for generating a forced flow, a fan LT is provided. To reclaim the air sucked in through the inlet El 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, 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. To drive off 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

Drying material ZEO stored amount of water can be released again.

Reference is now additionally made to FIGS. 2 to 4.

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-rinsing V or intermediate rinsing 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 eg. Wash 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 in the water tank cached liquid, such as water from a home-side supply system, can warm 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 is added. 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 wash program sequence according to FIG. 2, heating of liquid takes place only in the program step cleaning R. In this case, starting from a start temperature TO first 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 with the circulation pump UP circulating 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, 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 amount of liquid circulated by the circulation pump UP increased by a refilling step, for example, at time t1 (see Figure 2) and then increases the speed of the circulation pump UP, For example, continuously, until the circulating pump runs again in a run-out condition, ie, does not suck in air bubbles during operation, 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 Figure 2), while adhering to the cleaned items to be washed

Liquid, i. with rinse aid added water, can drain from the dishes due to gravity and in the pump sump PS of the interior of the IR

Dishwasher GS can collect. As a result, the of the

Sorption drying system reduces the amount of liquid to be absorbed 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 rinsing program according to FIGS. 3 and 4, liquid is heated in the first of the program steps, the pre-rinsing program step V. For this purpose, liquid is heated from a starting temperature TO during a phase PV to a temperature TV by means of the air heating HZ, as described above by means of the fan LT through the interior IR of the dishwasher GS and the sorption SB circulating air flow is generated. After reaching the temperature TV, 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, a further phase P3 (see FIG. 3) can be provided, while the water heater 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, it is provided in the exemplary embodiments according to FIGS. 3 and 4 that the liquid is heated during the rinsing step K. 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. Bezugszeichenhste

AB dripping phase

AU exhaust opening

BO floor assembly

El inlet

EL disposal line

GK crockery basket

GS dishwasher

HZ air heating

IR interior

LK air duct

LP drain pump

LT fan

NA post-wash phase

P ₁ . Phase 1 '

P1 phase 1

P2 phase 2

P3 Phase 3

P4 Phase 4

P5 Phase 5

PS pump sump

SA spray arm

SB sorption tank t1 Refill time

TO start temperature

T1 'temperature

T1 temperature

T2 temperature

T3 temperature

T4 temperature

T5 temperature

UP circulating pump

WZ water heating

ZEO drying material

ZL supply line

Claims

claims

1. A method for operating a dishwasher, in particular a domestic dishwasher, in which a plurality of program steps (V, R, Z, K, T) are passed, of which in at least one program step (V, R, Z) liquid on a maximum temperature (TV, T2, T3 ') is heated, and in a further program step rinsing (K) liquid reaches a maximum rinse temperature (T4, T5), characterized in that during at least one of the program steps (V, R, Z) liquid is heated to a maximum temperature (TV, T2, T3 ') that is substantially equal to or higher than the maximum rinse temperature (T4, T5).

2. The method according to claim 1, characterized in that during at least one program step cleaning (R) liquid to the maximum temperature (T2, T3 ') is heated.

3. The method according to claim 1 or 2, characterized in that during at least one program step cleaning (R) the maximum temperature in

Substantially between 5 and 50 ⁰ C, in particular between 10 and 30 ⁰ C higher than the rinse temperature (T4, T5), the liquid in the program step rinse (K) reached.

4. The method according to at least one of claims 1 to 3, characterized in that during at least one program step prewash (V) liquid is heated to the maximum temperature (TV).

5. The method according to at least one of claims 1 to 4, characterized in that during at least one program step pre-rinse (V) the maximum

Temperature substantially between 1 and 20 ° C, in particular between 5 and

10 ⁰ C higher than the maximum rinse temperature (T4, T5), the liquid in the

Program step rinsing (K) reached.

6. The method according to at least one of claims 1 to 5, characterized in that during at least one program step intermediate rinsing (Z) liquid is heated to the maximum temperature.

7. The method according to at least one of claims 1 to 6, characterized in that during at least one program step intermediate rinsing (Z) the maximum temperature substantially between 1 and 20 ⁰ C, in particular between 5 and 10 ⁰ C higher than the maximum rinse temperature (T4 , T5) is heated to the liquid in the program step rinsing (K).

8. The method according to at least one of claims 1 to 7, characterized in that at least temporarily during one of the program steps (V, R, Z), during which liquid is heated, a desorption of a reversibly dehydratable drying material, in particular zeolite (ZEO), is carried out.

9. The method according to at least one of claims 1 to 8, characterized in that during a program step drying (T) of items to be washed by passing moist air from an interior (IR) of the dishwasher (GS) is dried by a sorption drying system.

10. The method according to claim 9, characterized in that moisture of the moist air is absorbed by a reversible, dehydratable drying material, in particular zeolite (ZEO) of the sorption drying system.

11. The method according to at least one of claims 1 to 10, characterized in that liquid stored in a water tank of the dishwasher is used in at least one of the program steps (V, R, Z, K).

12. Dishwasher, in particular household dishwasher, with heating means for at least temporarily heating liquid to a maximum temperature (T1 \ T2, T3 ') during a program step (V, R, Z) of a plurality of program steps (V, R, Z, K), and configured to carry out a further program rinse (K), in which liquid reaches a maximum rinse temperature (T4, T5), characterized in that during at least one of the program steps (V, R, Z), liquid has a maximum temperature (TV, T2, T3 ') that is substantially equal to or higher than the maximum rinse temperature (T4, T5).

13. Dishwasher according to claim 12, characterized in that during at least one program step cleaning (R) the maximum temperature (T2, T3 ') is higher than the maximum rinse temperature (T4, T5).

14. Dishwasher according to claim 12 or 13, characterized in that during at least one program step cleaning (R) the maximum temperature

(T2, T3 ') is substantially between 5 and 50 ⁰ C, in particular between 10 and 30 ⁰ C higher than the maximum rinse temperature (T4, T5).

15. Dishwasher according to at least one of claims 12 to 14, characterized in that during at least one program step pre-rinse (V), the maximum temperature (TV) is higher than the maximum rinse temperature (T4, T5).

16. Dishwasher according to at least one of claims 12 to 15, characterized in that during at least one program step pre-rinse (V) the maximum temperature (TV) substantially between 1 and 20 ⁰ C, in particular between 5 and 10 ° C higher than the maximum Rinse temperature (T4, T5).

17. Dishwasher according to at least one of claims 12 to 15, characterized in that during at least one program step intermediate rinsing (Z), the maximum temperature is higher than the maximum rinse temperature (T4, T5).

18. Dishwasher according to at least one of claims 12 to 17, characterized in that during at least one program step intermediate rinsing (Z) the maximum temperature substantially between 1 and 20 ° C, in particular between 5 and 10 ° C higher than the maximum rinse temperature (T4 , T5).

19. Dishwasher according to at least one of claims 12 to 18, characterized in that a sorption drying system comprises at least one reversibly, dehydratable drying material, in particular zeolite (ZEO), at least partially during one of the program steps (V, R, Z) during which

Liquid is heated, is desorbable.

20. Dishwasher according to claim 19, characterized in that during a program step drying (T) of wash ware humid air from an interior (IR) of the dishwasher (GS) is durchleitbar by the sorption drying system.

21. Dishwasher according to at least one of claims 12 to 20, characterized in that the sorption drying system comprises at least one reversible, dehydratable drying material, in particular zeolite (ZEO), of which at least temporarily during the program step drying (T) humidity of the moist air can be accommodated ,

22. Dishwasher according to at least one of claims 12 to 21, characterized in that the dishwasher (GS) has a water tank for storing in at least one of the program steps (V, R, Z, K) usable liquid.