EP2207466A1

EP2207466A1 - Household appliance comprising an adsorption drying appliance

Info

Publication number: EP2207466A1
Application number: EP08843541A
Authority: EP
Inventors: Helmut Jerg
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2007-10-31
Filing date: 2008-10-15
Publication date: 2010-07-21
Anticipated expiration: 2028-10-15
Also published as: WO2009056451A1; ATE512618T1; EP2207466B1; DE102007052083A1; PL2207466T3; ES2366463T3

Abstract

The invention relates to a household appliance, especially a water-carrying household appliance, at least comprising an adsorption drying appliance (1) for the adsorbent drying of humid air, said household appliance being characterised by the following features: a housing (2) of the adsorption drying appliance, comprising a first cavity (7) containing a reversibly dehydrogenable solid adsorbent (3), and provided with an air outlet (6) fluidically connected to the first cavity (7); and a housing (9) of a heating module (8), comprising a second cavity (20) containing an electric heating element (15) for heating the adsorbent (3), and an air inlet (23) which is fluidically connected to the second cavity (20). The second cavity (20) is fluidically connected to the first cavity (7), and the module housing (9) is electrically insulated from the appliance housing (2).

Description

Domestic appliance with adsorption dryer

The invention relates to a domestic appliance according to the preamble of claim 1. State of the art

Conventional dishwashing machines use a number of different wash programs for washing dishes, which usually comprise at least one partial program step "pre-wash", one sub-program step "cleaning", at least one sub-program step "intermediate rinse", one sub-program step "rinse-out" and one partial program step "drying".

In modern dishwashers, various processes are used for the final drying of the cleaned items. For example, in the so-called self-heat drying, the items to be washed are heated during the partial program step "rinsing" by hot rinsing liquid having a temperature in the range of, for example 55 ° C - 75 ° C, so that the items to be washed during the partial program step "drying" by the intrinsic heat of even dries. Also known is the use of special heating equipment, such as hot air blower, which serve to heat the humid air mixture in the washing, which can then absorb a larger amount of water.

In particular, against the background of increased ecological requirements for the use of dishwashers an adsorption drying is increasingly used for drying the dishes, with moist air from the washing to dehumidify by a water adsorbing, reversibly dehydratable material (adsorbent) is passed. For example, zeolite is used as the adsorbent, an aluminum-silicate complex having a very high water absorption capacity.

In dishwashing machines with adsorption drying special adsorption drying devices are used for this purpose, which are connected in an air-conducting manner with the washing container for the items to be washed, the air to be dried or an air-steam mixture being fed to the adsorption drying apparatus via a fan. Is the water absorption capacity of the adsorbent used for dehumidification exhausted, This must be regenerated, which is usually done by the recorded

Water is expelled by heating the adsorbent again. For example, heated air is passed as regeneration air through the adsorbent to be regenerated for this purpose. In order to heat the regeneration air, absorption drying devices are typically provided with an electric heater.

In a common construction of such an adsorption drying apparatus, the electric heating device is used in the form of a (separate) heating module in the housing of the adsorption drying apparatus, for example by the heating module is locked in a space provided for this purpose device housing. Over a

Air supply opening of the heating module, the heating module is fed with air, which then heated by an electric heating wire, passed through the adsorbent to be regenerated, and is discharged via an air discharge opening again from the adsorption dryer.

In a structurally particularly simple construction of such an adsorption drying device, not only the regeneration air but also the air to be dehumidified is fed to the adsorbent via said air supply opening of the heating module, so that both the regeneration air and the air to be dehumidified take the same flow path. In this case, the adsorption drying apparatus can be operated in two different modes of operation, namely in a first mode of operation in which the dehumidified air is supplied to the adsorbent via the heating module, the electrical heating element is not energized, and in a second mode of operation, in which air heated by the energized heating wire and then fed to the adsorbent. Regeneration of the adsorbent by operating the adsorption drying apparatus in the second operating mode takes place, for example, after each complete execution of a washing program.

It has now been shown in practice that during operation of the adsorption drying apparatus in the first operating mode, due to a

Temperature difference between the generally warm humid air and the non-energized heating module, always condenses moisture from the humid air, which is on the heating wire and on the inner walls of the heating module as a water film reflected. Is now the regeneration of the adsorbent the

Operated adsorption dryer in its second mode of operation, the electric heating wire is energized, so that by the first still existing water film undesirable electrical leakage currents are derived via the usually grounded metallic housing of the adsorption dryer (electrical leakage).

In contrast, the object of the present invention is to provide an adsorption drying device as described above for dehumidifying moist air available, in which such based on a water film electrical leakage can be avoided.

This object is achieved according to the proposal of the invention by a domestic appliance with the features of the independent claim. Advantageous embodiments of the invention are indicated by the features of the subclaims.

The adsorption drying apparatus comprises a device housing which has a first cavity in which a solid adsorbent, for example zeolite, suitable for reversible dehydrogenation is accommodated. The apparatus housing of the adsorption drying apparatus is provided with an air discharge opening for discharging air from the adsorption drying apparatus, the air discharge opening being fluidly connected to the first cavity containing the adsorbent for this purpose.

The heating module for the regeneration (dehydrogenation) of the reversibly dehydratable adsorbent comprises a (separate) from the device housing

Module housing, which is provided with a second cavity. In the second cavity, an electrical heating element is added, which is suitable for generating ohmic heat. The module housing is provided with an air supply opening for supplying air to the heating module, which is fluidically connected to the second cavity (fluid or air conducting). In addition, the second cavity with the first cavity fluidly connected (fluid or air conducting), so that heated by the electric heating element air can be supplied to the adsorbent. The module housing is at least partially received within the device housing, whereby the heating module is integrated into the adsorption dryer.

The adsorption drying apparatus is essentially characterized by the fact that the module housing of the heating module is electrically insulated with respect to the apparatus housing of the adsorption drying apparatus.

Since the module housing of the heating module is electrically insulated with respect to the device housing of the adsorption drying apparatus, electrical leakage currents based on a water film formed by condensation, which can otherwise flow off via the generally grounded device housing of the adsorption drying apparatus, can advantageously be avoided.

In an advantageous embodiment of the adsorption drying device, the device housing is made of a cost-effective and technically easy to process metallic material, such as sheet metal, while the module housing is at least partially made of an electrically insulating plastic.

In particular, in the latter case, the module housing may be at least partially received in a mounting opening of the device housing, for example by means of a positive / non-positive connection such as a catch. In this case, it is particularly advantageous if the module housing comprises an electrically insulating material, in particular plastic, existing connection element for connection to the device housing, which is at least partially received in direct contact with the device housing in the mounting opening of the device housing, for example, locked therein is.

In a further advantageous embodiment of the adsorption drying apparatus, the second cavity is surrounded by an electrically insulating material, whereby an electrical insulation of the wall of the second cavity relative to the module housing can be achieved.

The invention will now be explained in more detail with reference to an embodiment, reference being made to the accompanying drawings. Show it: 1 shows a schematic sectional view of an embodiment of an adsorption drying device according to the invention with the heating module removed;

FIG. 2 is a schematic sectional view of a heating module for integration into the adsorption drying apparatus of FIG. 1. FIG.

Referring to Figs. 1 and 2, an embodiment of the adsorption drying apparatus and its modes of operation will now be explained.

Accordingly, the total designated by reference numeral 1 includes

Adsorption drying device consisting of a sheet metal device housing 2, which forms a first cavity 7. The housing cavity 7 contains a reversibly dehydratable adsorbent 3, for example zeolite.

In an upper housing section in FIG. 1, an air discharge opening 6 which opens into the first cavity 7 is designed to discharge air from the adsorption drying device 1. In a lower in Fig. 1 housing portion is an opening into the first cavity 7 insertion opening 5, which serves for inserting a heating module 8 shown in more detail in Fig. 2 is formed.

The heating module shown schematically in FIG. 2, designated overall by reference numeral 8, comprises a module housing 9, which in turn is composed of several components. Thus, the module housing 9 comprises a temperature-resistant, electrically insulating plastic, existing, substantially cylindrical plastic sleeve 10, which upon insertion of the heating module 8 in the

Insertion opening 5 comes into direct physical contact with the device housing 2. The plastic sleeve 10 surrounds with its one end partially a cylindrical first sheet metal sleeve 13, to which it is fastened by a plurality of fastening means 21, for example, screw, rivet or adhesive bonds. At its other end, the plastic sleeve 10 is encompassed by a substantially cylindrical fan outlet 11 and latched, for example. At an annular shoulder 22 of the fan outlet 1 1, a seal 22 is disposed between the second sheet metal sleeve 1 1 and the plastic sleeve 10, for example, a rubber O-ring. The first sheet-metal sleeve 13, in turn, partially surrounds a substantially cylindrical microtubule 14 made, for example, of electrically insulating mica (mica). In the second cavity 20 formed by the micropipe 14, which opens into the first cavity 7 via an end-side first cavity opening 24 accommodated when energized via the electrical connection contacts 18 ohm'sch heated heating wire 15 which is held by the Heizdrahtträgern 16. The Heizdrahtträger 16 are attached for this purpose on the module housing 9, which is not shown in Fig. 2 in detail.

In the plastic sleeve 10, a thermally triggering circuit breaker 17 is installed, which is suitable to turn off a current supply of the heating wire 15 when a selectable limit temperature within the second cavity 20 is exceeded. The fuse switch 17 may be conventionally based on, for example, an NTC resistor (NTC = Negative Temperature Coefficient).

The heating module 8 shown in FIG. 2 is inserted into the insertion opening 5 of the device housing 2 of the adsorption drying device 1. As shown in more detail in Fig. 2, the insertion opening 5 forming housing portion of the device housing 2 is formed for this purpose in the form of an inwardly slipped clamping ring. If the heating module 8 is inserted into the insertion opening 5, the heating module 8 expands the clamping ring in the radial direction, so that the device housing 2, the heating module 8 and the

Plastic sleeve 10 of the heating module 8 positively and non-positively surrounds. In particular, the heating module 8 can be pushed so far into the insertion opening 5 of the device housing 2 until the device housing 2 comes to bear against a formed on the outer surface of the plastic sleeve 10 radial annular collar 19.

In its installed position, the heating module 8 has a direct physical contact with the metallic device housing 2 only via the plastic sleeve 10, so that the heating module 8 is electrically insulated from the device housing 2.

The adsorption drying device 1 explained with reference to the figures serves for dehumidifying humid air or an air-steam mixture of a domestic appliance, such as a dishwasher. The adsorption drying apparatus 1 is for this purpose in the Household appliance installed, the device housing 2 is normally grounded electrically for safety reasons.

If the adsorption drying device 1 is installed in a dishwasher, the fan outlet 11 of the heating module 8 is connected in an air-conducting manner to the washing container provided for receiving items to be washed. In this respect, via a formed by the plastic sleeve 10 Luftzuleitöffnung 23 and a formed by the micahülse 14 second end face cavity opening 25 to be humidified moist air or a dehumidified air-steam mixture the second cavity 20 and thus on the first end-side cavity opening 24 the first cavity 7 can be supplied. In the flow path from the washing container to the heating module 8, for example, a fan is installed for this purpose, so that the heating module 8 can be subjected to overpressure. Similarly, air can be supplied to the second cavity 20 via the air supply opening 23, which is then supplied in a corresponding manner via the first end-side cavity opening 24 to the first cavity 7.

The adsorption drying apparatus 1 can thus be supplied with overpressure via the air feed opening 23, which air is again discharged from the adsorption drying apparatus via the air discharge opening 6. Here, the reversibly dehydratable adsorbent 3 is disposed within the flow path that on the air supply port 23 into the adsorption drying device 1 on and over

Luftableitöffnung 6 from the adsorption dryer 1 exiting air flows through the adsorbent 3 ..

The adsorption drying device 1 can be operated in a first operating mode in which humid air or an air-steam mixture is to be dehumidified. For this purpose, the moist air to be dehumidified or the air-vapor mixture to be dehumidified via the air inlet 23 to the second cavity 20 and then the first cavity 7, and after passage of the adsorbent 3 via the Luftableitöffnung 6 from the adsorption 1 again derived. If the absorption capacity of the adsorbent 3 is not exhausted, the adsorbent 3 absorbs water during the passage of moist air, so that dehumidified air is discharged via the air discharge opening 6. The adsorbent 3 is consumed by the water absorption and must after receiving one of the type and amount of the adsorbent dependent total amount of water can be regenerated by dehydration. The heating wire 15 is not energized in the first operating mode, so that during operation of the adsorption device 1 in the first operating mode due to the generally warm moist air from the washing a water film on the heating wire 15 and the inner walls of the heating module 8 can be reflected.

For regeneration of the adsorbent 3, the adsorption drying device 1 can be operated in a second operating mode. For this purpose, air is supplied via the air supply opening 23 to the second cavity 20 and then to the first cavity 7, and discharged again after passage of the adsorbent 3 via the discharge opening 6 from the adsorption device 1. The heating wire 15 is energized in the second operating mode via the two electrical contacts 18, so that the heating wire 15 generates ohmic heat and heats the passing air. Thus, heated air having a relatively high water absorption capacity passes through the adsorbent 3 and absorbs water, thereby dehydrating the adsorbent 3.

The adsorption device 1 can be operated in the second operating mode as desired, for example after the expiration of a selectable total operating time of the adsorption drying device 1 in the first operating mode or after each operation of the adsorption drying device 1 in the first operating mode.

Due to the electrical insulation between the module housing 9 and the device housing 2, electrical current can be avoided via the grounded device housing 2 when the heating wire 15 is energized, even if there is initially a water film on the heating wire 15 and the inner walls of the heating module. LIST OF REFERENCE NUMBERS

1 adsorption dryer

2 device housing

3 adsorbent 4 sieve filter

5 insertion opening

6 air discharge opening

7 first cavity

8 heating module 9 module housing

10 plastic sleeve

11 second sheet metal sleeve

12 seal

13 first metal sleeve 14 Micahülse

15 heating wire

16 heating wire carrier

17 safety switch

18 connection 19 ring collar

20 second cavity

21 fasteners

22 paragraph

23 air supply opening 24 first cavity opening 25 second cavity opening

Claims

claims

1. domestic appliance, in particular water-conducting domestic appliance, at least comprising an adsorption drying apparatus (1) for the adsorptive drying of moist air, having the following features: - a device housing (2) of the adsorption drying apparatus has a first

Cavity (7), in which a reversibly dehydratable solid adsorbent (3) is contained and the device housing (2) with a first cavity (7) fluidly connected Luftableitöffnung (6), - a module housing (9) of a heating module (8) has a second cavity (20), in which an electric heating element (15) for heating the adsorbent (3) is contained, wherein the module housing (9) with a with the second cavity (20) fluidly connected air supply opening (23 ) and the second cavity (20) is fluidly connected to the first cavity (7), wherein the module housing (9) is electrically isolated with respect to the appliance housing (2).

2. Domestic appliance according to claim 1, characterized in that the module housing (9) is at least partially received within the device housing (2).

3. Domestic appliance according to claim 1 or 2, characterized in that the

Device housing (2) made of a metallic material and the module housing (9) is at least partially made of an electrically insulating plastic.

4. Domestic appliance according to one of claims 1 to 3, characterized in that the module housing (9) at least partially in a mounting opening (5) of the

Device housing (2), in particular by means of a positive / non-positive connection, is added.

5. Domestic appliance according to claim 4, characterized in that the module housing (9) comprises an electrically insulating material, in particular plastic, existing connecting element (10), which in direct contact with the device housing (2) at least partially in the mounting opening (5 ) of the device housing (2) is received.

6. domestic appliance according to one of claims 1 to 5, characterized in that the second cavity (20) by a wall of an electrically insulating material (14) is formed.

7. adsorption drying apparatus for a household appliance according to one of claims 1 to 6.