EP2865312B1 - Dishwasher and method for operating a dishwasher - Google Patents

Description

The invention relates to a method for operating a dishwasher, comprising at least two rinsing zones arranged one above the other, in each of which a spray arm is arranged, and comprising a steam generating unit with a steam outlet opening, which is arranged in one of the rinsing zones. The invention further relates to a dishwashing machine suitable for carrying out the operating method.

Dishwashers often have a plurality of rinsing zones arranged one above the other, in each of which a spray arm for cleaning the items to be washed is arranged. In each of the rinsing zones while a receiving device for the items to be washed is provided, for example, a wire basket, which is configured differently in the different rinsing zones for receiving different items to be washed. It is usually intended to clean heavier and more heavily soiled dishes, in particular cookware, in a lower rinsing zone and lighter dishes in an upper or middle rinsing zone. In some dishwashers, in addition to the two rinsing zones mentioned, a third, generally flat, configured rinsing zone is arranged in the upper region of the dishwasher, which serves to receive lying sorted cutlery.

From the publication EP 2 156 774 A2 In addition, a dishwasher with a steam generating unit is known, which has a steam outlet opening in the region of the lower rinsing zone. Steam released into this rinse zone via the steam outlet opening allows an intensive cleaning effect on heavily soiled cookware. It is already known to operate the spray arms and the steam generating unit at the same time in such a dishwasher. The disadvantage of this is that the less hot water cools the hotter steam and thus reduces its additional cleaning effect. According to the cited document, the spray arms of the dishwasher and the steam generating unit are alternately operated to prevent the reduction of the cleaning effect of the steam by the water of the spray arms. However, this has the disadvantage that the available cleaning time is only used alternatively for steam or water purification.

It is therefore an object of the present invention to provide a dishwasher and a method for operating a dishwasher, in which the cleaning effect of steam of a steam generating unit is optimally utilized and at the same time the available cleaning time is utilized optimally.

This object is achieved by a dishwasher or an operating method for a dishwasher with the respective features of the independent claims.

An inventive method of operation of the type mentioned for a dishwasher is characterized in that the steam generating unit is at least temporarily operated when the arranged in the second rinsing spray arm is active.

Thus, for example, while in the lower area of the dishwasher in the first rinse zone an intensive cleaning using the steam generating unit, according to the invention in the second rinse zone, for example in the middle or upper area of the dishwasher, a cleaning of less heavily soiled dishes, such as glasses or plates take place , Only in the times when the spray arm in the first rinse zone is active, the steam generator is turned off, because the effect of hot steam would not exist while operating the Sprüharms in this Spühlzone and thus would be used for the steam generating unit energy ineffective.

In an advantageous embodiment of the method, the steam generation direction and the spray arm arranged in the first rinsing zone are operated several times alternately. In this way, an optimal cleaning result can be achieved in the first rinsing zone, in which strong impurities are first dissolved by the steam and removed by the spray arm.

In a further advantageous embodiment of the method, a rinsing bath heating is actuated only when the steam generating unit is not active. In this way, on the one hand, an excessive current consumption of the dishwasher can be prevented by simultaneous heating of the water in the device (rinsing liquor) and the steam generating unit. In addition, the energy introduced by the steam generating unit into the rinsing liquor is sufficient to maintain or even increase the temperature of the rinsing liquor.

According to a further advantageous embodiment of the method, the rotational speed of a circulating pump is varied, in particular reduced, when the steam generating unit is operated. The pumped by the circulating pump water of the rinsing liquor is supplied to the spray arm. The speed of the circulating pump thus determines the amount of mechanical cleaning power of the spray arms. A Drehzalvariation, in particular lowering, leads to an adjustment of the mechanical cleaning effect on the type of dishes that in the Rinsing zone, in which does not affect the steam generating unit, is usually more sensitive. In addition, the fact is taken into account that in addition to the steam generating device, which is also operated simultaneously with the spray arm for the second rinse zone, additional moisture is introduced into the washing compartment.

A dishwasher according to the invention is characterized in that a control device is provided which actuates the steam generating unit as a function of the position of the water separator. This results in the advantages described in connection with the method.

In an advantageous embodiment of the dishwasher, the steam generating unit has at least one flexible steam outlet opening. This can be positioned by the user as needed, so that the discharged steam can unfold advantageous exactly there its purifying effect, where it is needed.

Further advantageous embodiments and further developments of the method or the dishwasher are specified in the respective dependent claims.

Figur 1

eine schematische Schnittdarstellung einer Geschirrspülmaschine;

Figur 2

eine detaillierte Darstellung einer Dampferzeugungseinheit der Geschirrspülmaschine aus Figur 1;

Figur 3

ein schematisches Diagramm, das einenTemperaturverlauf einer Spülflotte sowie verschiedene Schaltzustände innerhalb einer Geschirrspülmaschine während eines Spülvorgangs wiedergibt;

Figur 4 und 5

eine schematische Darstellung einer Geschirrspülmaschine in einem zweiten Ausführungsbeispiel und

Figur 6 und 7

eine schematische Darstellung einer Geschirrspülmaschine in einem dritten Ausführungsbeispiel.

The invention will be explained in more detail by means of embodiments with reference to figures. The figures show:

FIG. 1

a schematic sectional view of a dishwasher;

FIG. 2

a detailed view of a steam generating unit of the dishwasher FIG. 1 ;

FIG. 3

a schematic diagram representing a temperature profile of a rinsing liquor and various switching states within a dishwasher during a rinsing process;

FIGS. 4 and 5

a schematic representation of a dishwasher in a second embodiment and

FIGS. 6 and 7

a schematic representation of a dishwasher in a third embodiment.

FIG. 1 schematically shows the structure for carrying out the method according to the invention suitable dishwasher 1. The dishwasher 1 is presently designed as a household dishwasher, but the invention can also be used in connection with a dishwasher for commercial and / or medical use.

The dishwasher 1 has a washing compartment, which is divided into two rinsing zones 10, 20 lying one above the other. In a lower area of the dishwasher 1, a collecting pot 2 for the rinsing liquor is arranged, that is to say the rinsing water circulating inside the dishwasher 1. With the collecting pot 2, a circulating pump 3 is connected and a Spülflottenheizung not shown here.

Each of the rinsing zones 10, 20 has a spray arm 11, 21, with which water of the rinsing liquor can be sprayed onto the items to be cleaned 13, 23 for its mechanical cleaning. To accommodate the items to be washed 13, 23, which may be, for example, dishes, cookware or cutlery, a movable crockery basket 12, 22 is provided in each case. Furthermore, a filter for filtering dissolved dirt particles and a drain pump are present in the dishwasher, which are not shown here for reasons of ease of representation.

Furthermore, a steam generating unit 30 is arranged in the bottom area of the dishwasher 1, which has a mushroom-shaped steam outlet opening 31 in this embodiment, which protrudes into the area of the first rinse zone.

The first rinsing zone 10, in which also the steam generating unit 30 acts, is usually the lower rinsing zone in the dishwasher 1. For the sake of simplicity, the first rinsing zone 10 will be referred to below as the lower rinsing zone 10 and the first spraying arm 11 as the lower spraying arm 11. Correspondingly, the second rinsing zone 20 is referred to as the upper rinsing zone 20 and the second spraying arm 21 as the upper spraying arm 21. In the lower rinsing zone 10, more heavily soiled items 13 are usually cleaned. Hereinafter, this example is referred to as cookware 13. In the upper rinsing zone less soiled and possibly more sensitive ware 23 is usually cleaned, hereinafter referred to as dishes 23 by way of example. By way of example, the embodiment of the FIG. 1 a dishwasher 1 with two rinsing zones 10, 20. It is noted that the inventive method can also be applied to a dishwasher having more than two rinsing zones arranged one above the other, for example three rinsing zones. For example, dishwashers with three rinsing zones are known in which the then upper third rinsing zone serves to receive flat cutlery. In such a Dishwasher would be the second rinse zone, the middle rinse zone, even if this is referred to in the present embodiment as the upper rinse zone.

FIG. 2 shows the steam generating unit 30 and the steam outlet opening 31 according to FIG. 1 detail. The steam generating unit 30 has a heater 32, which is arranged outside in the illustrated embodiment and acts on a heat exchange surface 33 on water 34 in the interior of the steam generating unit 30. In alternative embodiments, it may be provided to arrange the heater directly in the interior of the steam generating unit 30. The water 34 is heated by the heater 32 above its boiling point and forms in an evaporation chamber 35 steam 36, which enters through the outlet opening 31 as aussetender steam 37 in the washing compartment. The water 34 is brought through a water inlet opening 38 in the evaporator chamber 35, wherein a level sensor 39 monitors the water level and ensures a sufficiently high water level in the steam generating unit 30. The water inlet opening 38 is connected via a water valve 6 with a water-carrying line 5 within the dishwasher. The heater 32 and the water lock 6 are controlled by a control device 4, which also evaluates the output of the level sensor 39. The control device 4 is a central control device of the dishwasher 1, whose other connections in the schematic diagram of FIG. 2 are not shown.

FIG. 3 illustrates the inventive method with reference to a schematic diagram showing a temperature profile during a wash program and various switching states within the dishwasher. The inventive method can, for example, with a dishwasher according to FIG. 1 and will therefore be described by way of example with reference to FIG FIG. 1 and using the reference numerals inserted therein.

In the upper part of the a FIG. 3 the course of the temperature T _{SP of} the wash liquor within the dishwasher 1 during the progressive time t of the wash program is shown. In the second partial image b is shown for the same horizontal axis for the time t, which of the two spray arms 11, 21 is active. A spray arm is in the illustrated embodiment, characterized in that the circulating pump 3 downstream water diverter carries the conveyed by the circulation pump 3 water to either the spray arm 11 or the spray arm 21.

In the sub-picture c is again shown in the same horizontal axis for the progressive time t, which of the heaters are active. Heaters are either the symbolized with SF heating the rinsing liquor or the heater 32 of the steam generating unit 30. The steam generating unit 30 is so active when the heater 32 is turned on.

In the lower part diagram d is again shown on the same horizontal axis of the time t, with which speed U / min (revolutions per minute), the circulation pump of the rinsing liquor is operated.

As is apparent from the common consideration of the partial diagrams b and c, according to the invention, the steam generating unit 30 is operated by turning on their heater 32, while the upper spray arm 21 is active, but not when the lower spray arm 11 is active. In the times when the lower spray arm 11 is active, instead, the wash liquor heating is turned on to increase the temperature T _SF wash liquor in this portion of the wash cycle. From the panel a shows that in this cleaning section of the cleaning cycle, the temperature of the wash liquor increases continuously, which is due both to the Spülflottenheizung, as well as during the heat input into the wash compartment by the steam generating unit 30. Further, it can be seen that in the Times in which the steam generating unit 30 is active, in the zone in which the exiting steam 37 acts, a relation to the temperature T _SF rinse liquor increased temperature T _{D is} observed. The change between the elevated temperature T _D and the mechanical cleaning effect by activation of the lower spray arm 11 leads to a particularly good cleaning result.

As can be seen from the comparison of the partial images b and d, the activation effect of the lower spray arm 11 is additionally increased by raising the rotational speed of the pump. In contrast, while the upper spray arm 21 is active, the speed of the pump is reduced in order to clean the delicate dishes 23 as gently as possible in this part of the cleaning cycle.

The inventive method is in the illustrated embodiment of FIG. 3 in a first period of the cleaning cycle. Alternatively and / or additionally, it is also possible to use the steam generation in other sections of the cleaning cycle, for example in a rinse cycle in which the temperature is raised again (compare the section with a linearly increasing temperature in the right part of the diagrams).

In the FIGS. 4 and 5 and FIGS. 6 and 7 show two further exemplary embodiments of a dishwasher 1, which are particularly suitable for carrying out the method according to the invention.

In the embodiment of the FIGS. 4 and 5 a steam generating unit 30 is used, which instead of the mushroom-shaped steam outlet according to FIG. 1 a directed

Steam outlet 31, which is preferably rotatably mounted on the steam generating unit 30. The steam outlet opening 31 thus configured makes it possible to direct escaping steam 37 into those areas of the lower washing basket 12 in which the more heavily soiled cooking utensil 13 is located. In the examples of FIGS. 4 and 5 two different rotational positions of the steam outlet 31 are shown.

In the in the FIGS. 6 and 7 illustrated embodiment flexible hoses 31 b are provided, which can be bent or moved within the lower wire basket 12 by the operator of the dishwasher 1 so that escaping steam 37 can be selectively fed to the particularly intensive to be cleaned cookware. In the example shown, the two of these flexible hoses 31 b are provided, this line is exemplary and may be smaller or larger. To allow the flexible hoses 31 b to be in the extended position (FIG. FIG. 7 ) can be positioned, these are provided with a coupling which in the retracted state of the dish rack 12 ( FIG. 6 ) engages in a counter-coupling piece 31 a, which is connected to the steam generating unit 30.

LIST OF REFERENCE NUMBERS

1

Sink machine

2

collecting pot

3

circulating pump

4

control device

5

water supply

6

water valve

10

first rinse zone (lower rinse zone)

11

first spray arm (lower spray arm)

12

dish rack

20

second rinsing zone (upper rinsing zone)

21

second spray arm (upper arm of the arm)

22

dish rack

23

dishes

30

Steam generator

31

outlet

32

heater

33

Heat exchanger surface

34

water

35

evaporation chamber

36

emerging steam

37

exiting steam

38

water inlet

39

Level sensor

Claims (9)

1. Method for operating a dishwasher (1) comprising at least two washing regions (10, 20) arranged one on top of the other, in each of which a spray arm (11, 21) is arranged, said dishwasher further comprising a steam generation unit (30) having a steam outlet opening (31) arranged in one of the washing regions (10), the spray arms (11, 21) being alternately operated in the different washing regions (10, 20), the steam generation unit (30) not being operated when the spray arm (11) that is arranged in the first washing region is active, characterised in that the steam generation unit (30) is at least intermittently operated when the spray arm (21) that is arranged in the second washing region (20) is active.
2. Method according to claim 1, in which a rinsing solution heating system is activated when the steam generation unit (30) is inactive.
3. Method according to either claim 1 or claim 2, in which a speed of a circulating pump (3) which is hydraulically connected to the spray arms (11, 21) is modified, in particular reduced, when the steam generation unit (30) is operated.
4. Method according to any of claims 1 to 3, characterised in that the first spray arm (11) and the second spray arm (12) are alternately operated a number of times during one cleaning cycle.
5. Method according to any of claims 1 to 4, in which the steam generation unit (30) is operated during a first cleaning phase of the cleaning cycle.
6. Method according to any of claims 1 to 5, in which the steam generation unit (30) is operated during a rinsing phase of the cleaning cycle.
7. Dishwasher (1) comprising at least two washing regions (10, 20) arranged one on top of the other, in each of which a spray arm (11, 21) is arranged, said dishwasher further comprising a steam generation unit (30) having a steam outlet opening (31) arranged in one of the washing regions (10), the dishwasher (1) comprising a water deflector which optionally hydraulically connects the spray arms (11, 21) of the first and second washing regions (10, 20) respectively to a circulating pump, characterised in that a control device (4) is provided which actuates the steam generation unit (30) depending on the position of the water deflector.
8. Dishwasher (1) according to claim 7, in which the steam generation unit (30) comprises at least one flexible steam outlet opening (31 b).
9. Dishwasher (1) according to claim 8, in which the at least one flexible steam outlet opening (31 b) is connected to the steam generation unit (30) by means of a removable coupling.

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