EP1833352B1 - Dishwashing machine and method for operating the same - Google Patents

Description

The invention relates to a dishwasher with a rinsing container and devices for rinsing dishes by means of rinsing liquor and with a Sorptionstrockenvorrichtung which is air conductively connected to the rinse and having a sorbent column with reversibly dehydratable material, wherein the sorbent column is used to dry the dishes.

Such a dishwasher is from the EP 0 358 279 A1 known.

The invention further relates to a method for operating a dishwasher with at least one partial program step "drying", wherein in this part program step from a washing container of the dishwasher and / or ambient air is passed through a sorption column with reversibly dehydratable material in the washing and air during passage through the Sorption column is deprived of moisture.

Conventional dishwashing machines are known to have a rinsing process whose program sequence generally consists of at least one partial program step "pre-rinsing", one sub-program step "cleaning", at least one subprogram step "intermediate rinsing", one subprogram step "rinsing" and one subprogram step "drying". To increase the cleaning effect while the rinsing liquid is heated before or during a Teilprogrammschrittes. The heating of the rinsing liquid is usually carried out by means of electric heaters. For drying the items to be washed in a dishwasher different drying systems are known.

So is out of the DE 20 16 831 a dishwashing machine of the type mentioned, in which the air is passed from the washing container via a closable opening in the wall of the washing container on reversibly dehydratable material and from there via an opening to the outside. The desorption of the reversibly dehydratable material takes place during the standstill phase of the dishwasher, wherein the resulting water vapor is passed through the opening to the outside. The dishwasher described is disadvantageous from an energetic point of view, since the regeneration of the reversibly dehydratable material takes place during a standstill phase of the dishwasher, thus at a time when none of the partial program steps described above is performed. A further disadvantage is that damage to the surrounding kitchen furniture can not be ruled out by discharging the water vapor produced during the regeneration of the reversibly dehydratable material to the outside. The regeneration is associated with an additional energy requirement, which is incurred in addition to the energy required during the sub-program steps.

To keep the energy consumption when operating a dishwasher as low as possible, is from the DE 103 53 774.0 the Applicant discloses a dishwasher with a rinsing container and devices for rinsing crockery by means of rinsing, which has a sorptionskolonne air-conductively connected, reversibly dehydratable material containing the rinsing, wherein the sorbent on the one hand for drying the dishes and on the other hand for the desorption of the sorption used thermal energy Heating the rinsing liquor and / or the dishes located in the washing container is at least partially used.

To solve the same problem suggests the DE 103 53 775.9 the Applicant, for operating a dishwasher in the at least one partial program section "drying" air from a rinsing and / or from ambient air through a sorption column and into the washing container, wherein the sorbent column contains reversibly dehydratable material and the air withdraws moisture during the passage ,

By using reversibly dehydratable material with hygroscopic property, e.g. Zeolite, a heating of the material to be treated in the preceding part program step "drying" partial program step is normally no longer necessary. As a result, a considerable energy saving is possible.

From the EP 1 344 487 A2 a dishwashing machine is known in which the atmosphere in the dishwasher container is heated by means of a heater for drying the items to be washed and thereby the items to be washed are heated in the dishwasher container so that the items to be washed emit moisture. This moisture then condenses on a condensation surface, with the condensation running to the dishwasher sump. A moisture sensor measures the condensation of moisture on a condensation surface of the rinsing chamber.

The WO 98/33427 A1 discloses a dishwasher with an exhaust air drying device. A temperature sensor measures a temperature drop in the rinse tank , which is based on the fact that cold fresh air flows into the rinse tank.

The object of the present invention is to provide a dishwasher and method for operating the same, with which it is possible to efficiently clean and dry the items in the washing container located in the washing and the associated energy consumption as low as possible hold.

This object is achieved by the dishwasher according to the invention with the features according to claim 1 and by the inventive method with the features according to claim 9 or 12. Advantageous developments of the present invention are specified in the subclaims.

The dishwashing machine according to the invention has a rinsing container and devices for rinsing dishes by means of rinsing liquor and a sorption drying device, which is air-conduction-connected to the rinsing container and has a sorption column with reversibly dehydratable material, wherein the sorption column is used for drying the dishes, wherein a sensor means depending on the course of the washing program, wherein the sensor means is preferably arranged in the Sorptionstrockenvorrichtung. The sensor means may also be arranged outside the sorption drying device, for. B. in the washing container at the inlet.

While the wash program sequence of conventional dishwashers is subject to a time control, the invention proposes to arrange a sensor means in the dishwasher, more precisely in the sorption drying apparatus, in order to adapt a respective partial program step to the situation. As a result, a significant energy saving is possible. This is especially the case when the dishwasher is operated, for example, with only a small load. Both a partial program step with rinsing liquid to be heated (rinsing liquor) and the partial program step "drying" can be carried out with the same cleaning or drying effect in a shorter time, resulting in an energy saving due to the time saved compared to a time program control. The implementation of the shorter times of the partial program steps takes place on the basis of the assessment of the state of the reversibly dehydratable material in order to influence the course of the washing program, for example to start the next partial program step or to terminate the partial program step "drying".

In an advantageous embodiment, the wash program comprises at least one partial program step "drying", wherein the sensor means the state of the reversibly dehydratable material at least during the partial program step "drying" is detected and the one or more sensor values generated by the sensor means connected to the sensor means control and Evaluation device can be fed, which is adapted or designed to evaluate the sensor value or the sensor values and to influence the Spülprogrammablauf. Since the partial program step "Drying" is usually at the end of each wash program, influencing the program sequence consists in terminating the wash program.

In an expedient embodiment, the sensor means is designed as a temperature sensor. The temperature sensor is preferably arranged in the sorption drying device such that it can detect the temperature value prevailing in the sorption column or that prevailing at an outlet of the sorption column. This procedure is based on the finding that the outlet temperature of the air conducted through the sorption drying device during drying follows a characteristic temperature profile. For example, if the dishwasher is only partially loaded, less water will adhere to the items to be washed, which must be dried. As soon as the items to be washed and the rinsing container are dry, this manifests itself in a drop in the temperature of the air conducted through the sorption drying apparatus. When passing moist air through the Sorptionstrockenvorrichtung, more precisely, the sorption, this heats up due to the liberated condensation energy to high temperatures up to 150 ° C. As the drying process continues, the air passing through the sorption drying device contains less and less moisture so that less condensation heat is released. This manifests itself in a falling temperature of the exiting the Sorptionstrockenvorrichtung air. The temperature profile to be ascertained can be assigned to the degree of drying of the items to be washed inside the dishwasher.

Influencing the wash program sequence, i. a termination of the drying process, can thus be made possible on the basis of a value supplied by the sensor means in the control and evaluation device by a comparison with a threshold value. For this purpose, the control and evaluation device is set up or designed to compare the sensor values supplied by the sensor means with a threshold value.

An alternative embodiment provides that the control and evaluation device detects the time profile of the values supplied by the sensor means, and detects the slope of the profile of the sensor values or a turning point in the slope of the course as a criterion for influencing the Spülprogrammablaufs. In this refinement, the control and evaluation device is set up or designed to detect the time profile of the sensor values supplied by the sensor means, and to detect the slope of the profile of the sensor values or a turning point in the slope of the profile as a criterion for influencing the wash program sequence ,

An influence of the rinsing program sequence can be realized according to a further embodiment of the invention by forming the sensor means as a humidity sensor. The moisture sensor is preferably arranged in the sorption drying device such that it can detect the moisture prevailing at an outlet of the sorption column in the air stream. The evaluation in the control and evaluation means can take place on the basis of a comparison of the value supplied by the sensor means in the control and evaluation device with a threshold value. Alternatively, the control and evaluation device can detect the time profile of the values supplied by the sensor means and detect the slope of the profile of the sensor values or a point of inflection in the slope of the profile as a criterion for influencing the Spülprogrammablaufs.

The inventive method for operating a dishwasher, in particular a domestic dishwasher, with at least one partial program step "drying", wherein in this part program step, air from a washing container of the dishwasher and / or ambient air is passed through a sorbent column with reversibly dehydratable material in the washing and moisture is removed from the air during passage through the sorbent column, characterized in that the temperature of the air passed through the sorbent column is measured in or after the sorption column, to initiate the end of the partial program step "drying" depending on the measured temperature value or the measured temperature values.

This procedure makes it possible to draw conclusions about the moisture in the rinsing container so that in particular the degree of drying, regardless of the load and regardless of the time required so far, can be concluded.

In one embodiment of the method according to the invention, the measured temperature values are compared with a threshold value in order to initiate termination of the partial program step "drying" when the threshold value is exceeded or not reached.

In a further embodiment of the method according to the invention, the time profile of the measured temperature values is recorded and the slope of the course of the temperature values or a turning point in the slope of the course of the temperature values is used as criterion for the termination of the partial program step "drying".

The same advantages can be achieved by a method in which, according to the invention, the air humidity of the air passed through the sorption column is measured in or after the sorption column in order to initiate the end of the partial program step "drying" depending on the measured moisture value or the measured moisture values. In a corresponding manner, this can be initiated by a threshold value comparison or by monitoring the time profile of the moisture values.

Fig. 1

eine erfindungsgemäße Geschirrspülmaschine, und

Fig. 2

einen charakteristischen Temperaturverlauf der aus einer Sorptionstrockenvorrichtung austretenden Luft.

The invention and its advantages will be explained in more detail with reference to an embodiment. Show it:

Fig. 1

a dishwasher according to the invention, and

Fig. 2

a characteristic temperature profile of emerging from a Sorptionstrockenvorrichtung air.

FIG. 1 shows a schematic representation of a dishwasher 1 according to the invention with a washing container 2, are arranged in the baskets 3, 4 for the classification of not Pictured items to be washed.

The dishwasher 1 has a liquid-conducting connected to the washing container 2, reversibly dehydratable material 11, for. B. zeolite, containing sorption column 10, wherein the sorbent column 10, as will be explained in more detail below, on the one hand used for drying and on the other hand for heating conducted air, in particular as in the DE 103 53 774 and / or the DE 103 53 775 described. The content of these applications will be included in this application as far as appropriate.

The rinsing container 2 has an outlet 5 arranged in the described embodiment in its upper region with a line 6 to the sorption column 10 and an inlet 8 arranged in its lower region in the described embodiment with a line 7 from the sorption column 10. In line 6 to the sorption column 10, a fan 9 is arranged, which supplies the sorption column 10 air from the washing container 2.

For desorption of the reversibly dehydratable material 11, an electrical heating element 12 is arranged in the sorption column 10 in one embodiment shown. To influence the rinsing program sequence, in particular in the partial program step "drying", a sensor 13 is furthermore arranged in the flow direction at the outlet of the sorption column 10, which may be formed as a temperature or humidity sensor. Alternatively, it is also possible to arrange the sensor inside the sorption column 10.

A dishwasher is known to have a rinsing process whose program sequence generally consists of at least one partial program step "pre-rinsing", one sub-program step "cleaning", at least one sub-program step "intermediate rinsing", one sub-program step "rinsing" and one sub-program step "drying". According to the invention and in the illustrated embodiment, air from the Rinsing tank 2 on the one hand during the partial program step "drying" by the sorption column 10 and returned to the washing compartment 2 again. For this purpose, the blower 9 is turned on. The airway is indicated by the arrows A, B and C. The air introduced by the blower 9 via the line 6 into the sorption column 10 is deprived of all moisture by the reversibly dehydratable material 11. The air is heated by the liberated in the sorption column condensation heat of moisture or water vapor, which advantageously increases the moisture absorption capacity of the air. The now heated, eg up to 40 - 70 ° C, and very dry air now passes via the line 7 back into the washing container 2. The introduced in this, heated air is completely dry and has a high heat-up capacity due to the higher temperatures Moisture on. It rises in the washing container 2 upwards and absorbs the residual moisture on the items to be washed. It is now, as already described above, fed back to the sorption column 10.

Through the use of reversibly dehydratable material 11 in the part program section "drying" is a heating of the treated items to be treated in the program step "rinse", which precedes the drying, usually not necessary. This means a significant energy saving. As a result of the heating of the air, the moisture absorption capacity of the air is increased with each passing through the sorption column 10, which leads to an improvement in the drying result and to a shortening of the drying time.

For the desorption of the reversibly dehydratable material in the illustrated embodiment, air from the washing container 2 during a partial program step to be heated or possibly already heated rinsing liquid, preferably during the part program step "cleaning" and / or "pre-wash", in the described embodiment by the sorption column 10th and returned to the washing container 2 again. For this purpose, as already explained above, the fan 9 is turned on. The airway is indicated by the arrows A, B and C. Furthermore, the heater 12 is turned on to make the desorption of the reversibly dehydratable material 11.

As is known, reversibly dehydratable material 11 is heated to very high temperatures for desorption. The stored liquid emerges as hot water vapor. By the passage of air by means of the blower 9 through the lines 6, 7 accordingly the air path of the arrows A, B and C, the steam is passed into the washing tank 2 and also the air heated in the washing. The introduction of the hot steam and the heated air into the washing compartment 2 during the "cleaning" part program step into the washing compartment is largely sufficient to adequately heat the washing liquor and / or the dishes. Thus, a further heating largely eliminated, and the energy used for desorption can be almost completely used for heating the wash liquor and / or the dishes except for the low energy required to overcome the binding forces between water and reversibly dehydratable material. This ensures not only energy savings but also efficient cleaning of the items to be washed.

The energy consumption during the "drying" part program step is essentially caused by the operation of the blower for passing the air out of the washing container 2 through the sorption column 10 and back into the washing container. In this case, the outlet temperature of the air from the sorption column follows a characteristic temperature profile which in FIG. 2 is shown. Due to the initially very humid, passed through the sorbent 10, air produced during dehumidifying a very high heat of condensation, which heats up the reversibly dehydratable material and thus the air passed through this to temperatures up to about 160 ° C. As the time of the "drying" part-program step progresses, the air passed through the sorbent column 10 becomes more and more dry, so that the heat of condensation formed in the reversibly dehydratable material decreases, and the air passed through the sorbent column has a lower temperature.

It has been found that a certain temperature can be assigned to a certain degree of dryness. In the present embodiment, a temperature of about 57 ° C corresponds to a degree of drying of about 98%. This characteristic temperature, which can be used as a threshold value for comparison with the temperature values determined by the temperature sensor, depends in practice on how the sorption column is formed. Possible influencing factors here are the flow resistance of the sorption column, which depends essentially on the diameter of the zeolite spheres and the geometric dimensions of the sorption column.

In FIG. 2 the temperature curves of the air emerging from the sorption column are shown once for the case of a normal load (case 1) and once for the case of a small load (case 2). It can be clearly seen that in the case of a low loading of the dishwasher, the temperature drops more after reaching its peak value, so that the threshold (broken line at about 57 ° C) is reached at an earlier time. As a result, this means that the drying process is completed faster in a lightly loaded dishwasher than in a normally loaded dishwasher.

In addition to a threshold value comparison, the gradient of the course of the measured temperature can also be used as a criterion for terminating the partial program step "drying". Furthermore, it is possible to detect a characteristic inflection point in the course of the temperature.

In another variant, not shown, the measured moisture is used instead of the temperature to influence the rinsing program sequence. The procedure corresponds in principle to the one just described.

A further shortening of the drying time results when in the partial program step preceding the partial program step "drying", usually rinsing, a heating of the treatment liquid or of the product to be rinsed has taken place. The temperature profile in the partial program step "drying" then follows a higher slope, whereby the drying process can be further accelerated.

With the present invention, it is possible to operate dishwashers of the type described economically, to dry the material to be dried efficiently and to keep the associated energy expenditure due to the reduction of time as small as possible.

LIST OF REFERENCE NUMBERS

1

dishwasher

2

rinse tank

3

dish rack

4

dish rack

5

outlet

6

management

7

management

8th

inlet

9

fan

10

sorption

11

reversibly dehydratable material

12

heating element

13

sensor means

A, B, C

By air

Claims (14)

1. Dishwashing machine (1) with a tub (2) and facilities for washing dishes by means of washing liquor and also with a sorption drying facility, which has an air-conducting connection to the tub and has a sorption column (10) with reversibly dehydratable material (11), wherein the sorption column (10) is employed for drying the dishes, characterised in that a sensor means (13) is present which serves to capture the state of the reversibly dehydratable material (11) during the execution sequence of a washing program in order to influence the execution sequence of the washing program as a function of said state, wherein the sensor means (13) is preferably disposed in the sorption drying facility.
2. Dishwashing machine according to claim 1, characterised in that the washing program includes at least one subprogram step "drying" and with the sensor means (13) the state of the reversibly dehydratable material (11) is able to be captured, at least during the subprogram step "drying" and the sensor value or sensor values generated by the sensor means are able to be supplied to a control and evaluation device connected to the sensor means (13), which is configured or embodied to evaluate the sensor value or the sensor values and to influence the dishwashing program execution sequence.
3. Dishwashing machine according to claim 1 or 2, characterised in that the sensor means (13) is embodied as a temperature sensor.
4. Dishwashing machine according to claim 3, characterised in that the temperature sensor is disposed in the sorption drying facility such that it can capture the first temperature value obtaining in the sorption column (10) or at an output of the sorption column (10).
5. Dishwashing machine according to claim 1 or 2, characterised in that the sensor means (13) is embodied as moisture sensor.
6. Dishwashing machine according to claim 5, characterised in that the moisture sensor is disposed in the sorption drying facility such that it can capture moisture present in the air flow at an output of the sorption column (10).
7. Dishwashing machine according to one of claims 1 to 6, characterised in that the control and evaluation device is configured or embodied to compare the sensor values supplied by the sensor means (13) with a threshold value.
8. Dishwashing machine according to one of claims 1 to 6, characterised in that the control and evaluation device is configured or embodied to capture the timing curve of the sensor values supplied by the sensor means (13) and to detect the rise in the curve of the sensor values or a turning point in the rise of the curve as a criterion for influencing the washing program sequence.
9. Method for operating a dishwashing machine (1) with at least one "drying" subprogram step, wherein in this subprogram step, air is conveyed from a tub (2) of the dishwashing machine (1) and/or ambient air is conveyed through a sorption column (10) with reversibly dehydratable material (11) into the tub (2) and moisture is extracted from the air during the conveyance through the sorption column (10), characterised in that the temperature of the air conveyed through the sorption column (10) is measured in or after the sorption column (10), in order to initiate the end of the subprogram step "drying" as a function of the measured temperature value or the measured temperature values.
10. Method according to claim 9, characterised in that the measured temperature values are compared with a threshold value in order to initiate the end of the subprogram step "drying" if the threshold value is exceeded or not reached.
11. Method according to claim 9 or 10, characterised in that that the timing curve of the measured temperature values is captured and the rise in the curve of the temperature values or a turning point in the rise in the curve of the temperature values is included as a criterion for ending the subprogram step "drying".
12. Method for operating a dishwashing machine (1) with at least one subprogram step "drying", wherein in this subprogram step air is conveyed from a tub (2) of the dishwashing machine (1) and/or ambient air is conveyed through a sorption column (10) with reversibly dehydratable material (11) into the tub (2) and moisture is withdrawn from the air while it is being conveyed through the sorption column (10), characterised in that the air humidity of the air conveyed through the sorption column (10) is measured in or after the sorption column (10), in order to initiate the end of the subprogram step "drying" as a function of the measured temperature value or the measured temperature values.
13. Method according to claim 12, characterised in that the measured humidity values are compared with a threshold value, in order to initiate the end of the subprogram step "drying" if the threshold value is exceeded or not reached.
14. Method according to claim 12 or 13, characterised in that the timing curve of the measured moisture values is captured and the rise in the curve of the moisture values or a turning point in the rise of the curve of the moisture values is included as a criterion for ending the subprogram step "drying".

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