WO2004058035A1

WO2004058035A1 - Dishwasher

Info

Publication number: WO2004058035A1
Application number: PCT/EP2003/013661
Authority: WO
Inventors: Martin Stickel
Original assignee: BSH Bosch und Siemens Hausgeräte GmbH
Priority date: 2002-12-20
Filing date: 2003-12-03
Publication date: 2004-07-15
Also published as: EP1578243A1; DE10260163A1; AU2003303359A1

Abstract

The invention relates to a dishwasher for receiving articles to be cleaned disposed in a washing compartment (1), which comprises a device for circulating liquid, a device for heating the liquid and a spray device for applying the liquid to the articles to be cleaned by the selection of a washing cycle, using a control unit, and a device for providing steam. According to the invention, the device for providing steam has a separate steam chamber (3) with integrated heating (8) that is linked with the bottom of the washing compartment (1). A steam dispenser (5) is coupled with the steam chamber (3) and the bottom (2) of the washing compartment (1) and is adapted to adjust the pressure of the steam flowing into the washing compartment (1). The invention provides a compact design of the device for providing steam which, inter alia, allows a variable selection of the volume to be exposed to the steam in the washing compartment depending on whether a low or high steam pressure is adjusted. It also allows for an intensive and specific soaking of particularly dirty articles by controlled exposure to steam from the steam dispenser with a high degree of effectiveness. The inventive dishwasher also prevents the uncontrolled random escape of steam into the entire washing compartment.

Description

dishwasher

The invention relates to a dishwasher for receiving items to be washed arranged in a washing container, with a device for circulating liquid, a device for heating the liquid and a spray device for applying the liquid to the items to be washed when a washing process is selected by a control device, and with a device to provide steam.

From DE 29 00 954 A1 a dishwasher for receiving items to be washed arranged in a washing container is known, which has a pump for circulating liquid, a continuous-flow heater for heating the liquid and a spray device for applying the liquid to the items to be washed when a washing process is selected by a control device having. In addition, the dishwasher has a device for providing steam upon activation of a separate steam rinsing cycle that takes place between the pre-rinse cycle and the main rinse cycle. This device for providing the steam is freely arranged directly below the spray device directly in the washing container and essentially consists of a heater and a cover which is open at the bottom and has a protruding section into which steam discharge openings are formed. During the steam rinse cycle, the water is heated up by the heater - after it has been let into the rinse tank to a predetermined water level - so that water vapor is generated, which can then escape uncontrollably at any point via the steam discharge openings in the rinse tank. The steam rinse serves to dissolve heavily soiled items and is initiated by the user when the user selects an appropriate program via the control device. For descaling, the device responsible for providing the steam must be manually removed from the dishwasher and cleaned.

A working container for a dishwasher is known from DE 44 01 420 C1, to the bottom of which a heating element is thermally coupled. The heating element, which is designed as a closed steam chamber, is filled with a liquid only at its lowest point, where a heating element is located. A chamber wall section of the heating element is arranged liquid-tight in an opening in the bottom of the working container. The invention is based on the object of creating a dishwasher of the type described at the outset, by means of which the cleaning result supported by the provision of steam is improved, in particular for heavily soiled items to be washed.

This object is achieved by an inventive dishwasher according to patent claim 1.

Further features of the invention and advantageous embodiments of the invention are characterized in the subclaims.

Starting from a dishwasher for receiving items to be washed arranged in a washing container with a device for circulating liquid, a device for heating the liquid and a spray device for applying the liquid to the items to be washed when a washing process is selected by a control device, and with a device for providing of steam, according to the object of the invention the device for providing the steam has a separate steam chamber with integrated heating, which is connected to the bottom of the rinsing container, a steam nozzle being coupled to the steam chamber and the bottom of the rinsing container, through which the pressure of the steam to flow into the rinse tank is adjustable.

The special arrangement of a separate steam chamber and a steam nozzle with the rinsing tank bottom results in a device for providing the steam with the following advantages:

- Intensive and targeted softening of heavily soiled items by controlled exposure to steam from the steam nozzle,

- variable determination of the volume of steam in the washing container depending on the set low to high steam pressure,

- Avoiding an uncontrolled inflow of the steam at any point in the entire washing container, - Less back-soiling and better washing results for an optimal cleaning result with the greatest possible efficiency of the steam, Reduction of the consumption of liquid - preferably water - by the

Penetration of the dirt with steam and subsequent reuse of the condensed steam as water,

Reduction of energy consumption due to the "preheating" of the dishes

Steam.

According to an advantageous embodiment of the invention, the pressure of the steam determines the size of the point or zone through which the incoming steam flows and which is intended to hold the items to be washed. This allows the cleaning result to be flexibly optimized in relation to the point or zone to be steamed, which in each case brings optimum efficiency for the set low to high steam pressure. According to a preferred embodiment of the invention, the pressure of the steam is determined by the cross section of the steam nozzle.

In a particularly advantageous manner, the steam nozzle has a plurality of nozzle openings. When the state changes from liquid to gaseous, a pressure is generated, the height of which is determined in a simple and effective manner by the nozzle openings, since it has to build up against them.

It has also proven to be advantageous for the steam nozzle to be provided with a check valve and for a pressure pump or a pressure valve to be used. This allows steam to be generated effectively at high pressures in the steam chamber with integrated heating.

The steam nozzle is preferably provided with a protective cap in order to prevent it from becoming dirty and clogged. B. by dirt particles falling into the nozzle openings in particular - to be prevented. The protective cap is preferably mushroom-shaped. This creates a protective device protruding beyond the side walls of the steam nozzle in the manner of a bell.

It has proven to be of particular value according to an advantageous embodiment of the invention in which the steam chamber with integrated heating is surrounded by thermal insulation. This prevents heat loss to the outside. According to a further advantageous embodiment of the invention, the amount of liquid that is fed to the steam chamber can be controlled by a pump or a valve. As a result, the most exact possible dosage of the amount of liquid can be achieved, which advantageously leads to rapid steam generation.

According to a further advantageous embodiment of the invention, the pump, the valve and the heating of the steam chamber can be controlled in a coordinated manner by the control device in such a way that after a time for preheating the liquid, the steam is generated immediately when the liquid is fed into the steam chamber.

With the present invention, a dishwasher of the type described at the outset is created, by means of which the cleaning result assisted by the provision of steam is improved, in particular for heavily soiled items to be washed.

The invention is explained below with reference to the exemplary embodiment shown in the drawing.

The single figure shows the devices involved in steam generation in a dishwasher, of which, in a sectional side view, part of the interior of a washing container 1, in which, as is known, items to be washed - for example in a crockery basket - are arranged, a separate steam chamber 3 with integrated heating 8, a steam nozzle 5 with a protective cap 7 to prevent contamination and / or clogging, and a heat insulation 4 surrounding the steam chamber 3 to minimize the heat loss from the heater 8. In addition, an operating panel 16 is shown in the figure, which is usually located on the front of the dishwasher in the upper Area is attached and via which, depending on the selection of a program - for example a rinsing and drying process and / or a steaming process - a control device of the program-controlled dishwasher is activated accordingly by a user, which subsequently activates the individual program sc hritte controls. The control panel 16 comprises program selection switches - for example in the form of pushbuttons 19 - for activating the different programs, at least one display element 20 and an intervention 18 for actuating an appliance door attached to the front of the dishwasher for opening and closing the washing compartment 1. The rinsing container 1 consists of a base 2, which runs obliquely in the selected example, and side walls, of which a rinsing container wall 2 'is shown in the sectional view shown, and a rear wall. The device for providing the steam has the separate steam chamber 3, preferably made of light metal, with the integrated heater 8, which - in the example below the washing compartment 1 - is connected to the base 2. The steam nozzle 5, through which the pressure of the steam for flowing into the washing compartment 1 can be variably adjusted, is coupled both to the steam chamber 3 and to the bottom 2 of the washing compartment 1. The steam nozzle 5 protrudes somewhat into the interior of the rinsing container 1 and is preferably firmly anchored to the base 2 with its lateral nozzle walls 5, which have an L-shape for better fastening, for example. It has an inlet opening 6 'at its lower end facing the steam chamber 3, through which the steam can enter the steam nozzle 5 after the change of state from liquid to gaseous, and preferably a plurality of nozzle openings 6 at its upper end facing the washing container 2 , through which the steam can escape into the washing compartment 1 at a certain point or zone 17 - which can be specially marked and designed to hold particularly dirty items to be washed. The protective cap 7 of the steam nozzle 5 is arranged above the nozzle openings 6 and is mushroom-shaped in the manner of a bell in order to prevent particles approaching from all sides from penetrating into the nozzle as far as possible.

The height of the steam pressure, which is preferably set via the cross section of the steam nozzle 5, determines the size of the point or zone 17 in the washing container 1 through which the incoming steam flows and which is intended to receive the special wash ware. When the state changes from liquid to gaseous, the pressure is generated , the height of which is determined in a simple and effective manner by the nozzle openings 6, since it has to build up against them. The steam nozzle 5 can preferably be provided with a check valve, and a pressure pump or a pressure valve is also used. As a result, steam can be generated effectively at high pressures in the steam chamber 3 with integrated heating.

The dishwasher additionally has spray devices - for example in the form of a spray arm arranged below the upper crockery basket in the washing container 1 - for applying a liquid - usually water - to the dishes when activated. rinsing process by the control device coupled to the program selector switch. A pump - which cannot be seen here in the side view - circulates the liquid 9 - for example softened water - before it is fed to a continuous flow heater or heat exchanger 10 for heating the liquid and then to the spray device.

The hydraulic circuit provided for steam generation comprises a plurality of supply lines and discharge lines for conveying the liquid 9, of which a supply line 12 acts directly on the water outlet 11 of the heat exchanger 10 and opens into a device .15. Another feed line 13 connects the outlet of the device 15 to the inlet of the separate steam chamber 3. This device 15 consists of an unpressurized pump or a valve through which the softened water is conveyed from the heat exchanger 10 to the separate steam chamber 3 , The amount of liquid 9 conveyed by the feed pump 15 - e.g. a diaphragm pump - or be metered exactly by the valve, so that the steam can be generated quickly by heating the supplied liquid 9 in the steam chamber 3 through the heater 8, which is preferably designed as a tubular heater or thick-film heater.

Both the heater 8 and the device 15 - feed pump or valve - are connected via control lines 21 - which are connected on the input side to control inputs of the pump / valve - and control lines 22 - which are connected on the input side to control inputs of the heater 8 - via which those with the Program selection switch coupled control device controlled controlled such that the liquid 9 of the steam chamber 3 is supplied only after a sufficiently long preheating time. This ensures that steam is generated immediately when the water is supplied - this corresponds to the effect that a drop of water has on a hob.

There are also discharge lines for removing liquid - eg rinsing liquid after a rinsing process - and a collecting device - eg a sieve - for collecting solid parts and particles, but are not shown due to their lack of importance for the steam generation process. The location or zone 17 provided for receiving the special wash items - possibly also a single and predetermined one - can preferably be set up in the vicinity of a wash tub wall. This allows the cleaning result to be further optimized, since the only outlet point for the steam to act on the heavily soiled items in the border area of the Rinsing container 2 is located and the other “normal” washware - arranged in the other area of a crockery basket - is not affected.

The connection of a separate steam chamber with the bottom of the rinsing tank on the one hand and the coupling of a steam nozzle with the bottom of the rinsing tank and the separate steam chamber on the other hand creates a compact arrangement for the device for providing the steam, which among other things has above all advantages. A variable determination of the volume of steam in the washing container depending on the set low to high steam pressure, as well as an intensive and targeted softening of heavily soiled items by controlled application of steam from the steam nozzle with high efficiency. An uncontrolled escape of the steam in the entire washing container is also avoided.

Claims

claims

1. Dishwasher for receiving items to be washed arranged in a washing container, with a device for circulating liquid, a device for heating the liquid and a spray device for applying the

Liquid on the items to be washed when a washing process is selected by a control device and with a device for providing steam, characterized in that the device for providing the steam has a separate steam chamber (3) with an integrated heater (8) which is connected to the Bottom (2) of the washing container (1) is connected, and that with the steam chamber (3) and the bottom (2) of the washing container (1) a steam nozzle (5) is coupled through which the pressure of the steam for flowing into the washing container (1) is adjustable.

2. Dishwasher according to claim 1, characterized in that the pressure of the steam determines the size of the point or zone (17) penetrated by the inflowing steam and intended for receiving the items to be washed.

3. Dishwasher according to one of the preceding claims, characterized in that the pressure of the steam through the cross section of the steam nozzle

(5) is determined.

4. Dishwasher according to one of the preceding claims, characterized in that the steam nozzle (5) has a plurality of nozzle openings (6).

5. Dishwasher according to one of the preceding claims, characterized in that the steam nozzle (5) is provided with a check valve and a pressure pump or a pressure valve are used.

6. Dishwasher according to one of the preceding claims, characterized in that the steam nozzle (5) is provided with a protective cap (7).

7. Dishwasher according to claim 6, characterized in that the protective cap (7) is mushroom-shaped.

8. Dishwasher according to one of the preceding claims, characterized in that the steam chamber (3) with integrated heater (8) is surrounded by thermal insulation (4).

9. Dishwasher according to one of the preceding claims, characterized in that the amount of liquid (9) which is fed to the steam chamber (3) can be controlled by a pump (15) or a valve.

10. Dishwasher according to claim 9, characterized in that the control device controls the pump (15) or the valve and the heater (8) of the steam chamber (3) in such a way that they can be controlled such that after a time for preheating the liquid (9) the steam is generated immediately when the liquid (9) is fed into the steam chamber (3).