WO2015082178A1

WO2015082178A1 - Household appliance

Info

Publication number: WO2015082178A1
Application number: PCT/EP2014/074354
Authority: WO
Inventors: Kudret Baysal; Markus Spielmannleitner; Florian Eder
Original assignee: BSH Hausgeräte GmbH
Priority date: 2013-12-05
Filing date: 2014-11-12
Publication date: 2015-06-11
Also published as: DE102013224951A1

Abstract

The invention relates to a household appliance (1, 51) comprising a number of walls (4, 5, 6, 56, 57, 65) surrounding an internal space (3, 53), said walls having surfaces (4a, 5a, 6a, 56a, 57a) facing the internal space (3, 53). At least one part of the surfaces (4a, 5a, 6a, 56a, 57a) is designed in such a way that, drops of water (11, 66) forming on this part of the surfaces (4a, 5a, 6a, 56a, 57a) have a receding contact angle (ϴ_R) of at least 60°. In addition, or alternatively, a component (24a) of the household appliance (1) is arranged inside the internal space (3), said component having a further surface (25), at least one part of which further surface (25) is designed in such a way that drops of water (11) forming on this part of the further surface (25) have a receding contact angle (ϴ_R) of at least 60°. The invention also relates to a household appliance (1, 71) having a heat-exchanger, in particular an evaporator (24, 84) of a coolant circuit (20, 80), said heat-exchanger having a surface (25, 85), at least part of which surface (25, 85) of the heat-exchanger is designed in such a way that drops of water (11) forming on this part of the surface (25, 85) of the heat-exchanger have a receding contact angle (ϴ_R) of at least 60°.

Description

household appliance

The invention relates to a household appliance, in particular with an interior.

An example of a household appliance with an interior is a household refrigerator, which has an inner container, which limits a provided for storing food, cooled by means of a refrigerant circuit interior. In particular, in refrigerators of household refrigerators may be incurred undesirable amounts of condensate. This condensate forms z. On glass plates, from where it can drip onto the stored food, or in other storage areas of the household refrigerating appliance, such as e.g. Drawers. By opening a provided for closing the coolable interior door panel and associated air exchange with the installation room of the household refrigerator, caused, but also by stored food, such. Leafy vegetables, moisture in the form of water gas can enter the coolable interior.

The condensation of the water gas takes place in particular at the points at which the dew point of the air located there is below. If the actively cooled evaporator of the refrigerant circuit is arranged in the coolable interior, this effect is indirectly utilized. This removes water from the coolable interior by condensing the moist air at the evaporator and leads it out of the coolable interior to the outside.

Especially due to the increase in efficiency prevail on the evaporators always higher temperatures than household refrigerators with lower energy efficiency. This reduces the temperature difference between the evaporator, the surrounding air and the remaining components of the inner container. Thus, the effectiveness of the evaporator sinks as a cold sink. This results in an at least partial shift of the condensation from the evaporator, for example, to shelves of household refrigeration appliance. One measure for dehumidifying the coolable interior is the targeted condensation on the evaporators. Through targeted ventilation an air flow is generated, which generates an increased condensation on the evaporator. In order to a reduction in the relative humidity of the air in the inner container is achieved and thus reduces the condensation, for example on the shelves. The condensate on the evaporator is derived for example via a trough in an evaporation tray in the engine room of the household refrigerator and thus avoided increased water accumulation in the coolable interior.

Another example of a household appliance with an interior is a household dishwasher that includes a washing container that confines the interior. The interior of the household dishwasher is provided for loading items to be washed. During operation of the domestic dishwasher, water drops may form on the surfaces of the washing container facing the interior due to condensation, in particular during drying of the rinsed items to be washed.

Object of the present invention is to carry out a household appliance with an interior such that the condensation rate of certain, facing the interior surfaces and / or that the condensation rate is increased on the surface of a disposed within the interior of the household appliance component.

The object of the invention is achieved by a domestic appliance, comprising a plurality of walls delimiting an interior, the surfaces facing the interior, of which at least a part of the surfaces is formed such that on this part of the surfaces forming water droplets a retraction angle of at least 60 °, and / or in which within the interior of a component is arranged as part of the household appliance, which has a further surface, wherein at least a portion of the further surface is formed such that on this part of the further surface forming water droplets a retreat angle of at least 60 °.

Another aspect of the invention relates to a domestic appliance, comprising a heat exchanger, in particular an evaporator of a refrigerant circuit having a surface (wherein at least a part of the surface of the heat exchanger is formed such that on this part of the surface of the heat exchanger forming water droplets a retreat angle of at least 60 °. According to an advantageous variant of the domestic appliance according to the invention, the part of the surfaces and / or the further surface and / or the surface of the heat exchanger is designed such that water droplets forming on this part of the surfaces or the further surface have a retraction angle of at least 70 °, preferably at least 80 °.

The part of the surfaces is preferably an actively cooled surface, e.g. the surface of an evaporator. According to one embodiment of the household appliance according to the invention, the walls of the interior comprise two side walls, a rear wall and a ceiling, wherein at least part of the surfaces of at least one of the side walls and / or the rear wall is formed in such a way that drops of water forming there have a retraction angle of at least 60 ° , in particular of at least 70 °, preferably at least 80 °.

The household appliance according to the invention is e.g. a household refrigerator, preferably a household refrigerator. The household refrigerator or household refrigerator comprises a refrigerant circuit with an evaporator for cooling the interior and a heat-insulated body with an inner container having the surfaces, wherein the interior is provided for storing food. According to this variant, the interior space is thus a coolable interior, which is limited by the surfaces of the inner container. At least a portion of these surfaces are formed so that forming water droplets have a retraction angle of at least 60 °. The domestic refrigerator or household refrigerator may e.g. a hinged door leaf to close and open the coolable interior.

The evaporator can be arranged, for example, behind the surface of the inner container, which is at least partially formed such that water droplets forming there have a retraction angle of at least 60 °, in particular of at least 70 °, preferably at least 80 °. The inner container may have a rear wall, a ceiling and two side walls. The evaporator is preferably arranged behind the rear wall. He can also behind at least one of the side walls be arranged and / or at least partially extend behind the ceiling. The part of the surface of the inner container, behind which the evaporator is arranged, thus represents an actively cooled surface. The corresponding wall preferably comprises a gutter, which is intended to collect on the corresponding wall forming water droplets and to lead out of the coolable interior ,

The inner container of the household appliance according to the invention designed as a domestic refrigerator or household appliance may have at least one vertically extending wall and the evaporator may be designed as a laminar evaporator, eg as a Rollbond evaporator, which is arranged at a distance from the vertical wall within the coolable interior and the has a surface which is at least partially formed such that there forming water droplets have a retraction angle of at least 60 °, in particular of at least 70 °, preferably at least 80 °. This planar evaporator is thus an example of the arranged inside the component of the household appliance according to the invention, which comprises the further surface. The planar evaporator is also a heat exchanger. The planar evaporator is eg a Rollbond evaporator. The vertical wall is for example the rear wall or one of the side walls and in particular comprises the gutter. Characterized in that according to the invention the surface or the further surface is formed such that water droplets forming there have a retraction angle of at least 60 °, in particular of at least 70 °, preferably at least 80 °, the condensation rate, ie the amount of condensate per time or condensation surface on the corresponding surface, for example, the evaporators or actively cooled surfaces, such as the surfaces of the inner container, even at relatively high surface temperatures improved. For example, a lower subcooling (ie temperature difference) is particularly advantageous in the case of droplet condensation, because here the spontaneous formation of condensation nuclei on the surface does not take place to such a high degree, as in the stronger subcooling. This lower supercooling thus causes the merger of smallest water droplets is less hindered by the newly formed germs and thus a larger heat exchanger surface is present, which in turn has a positive effect on the efficiency of the household refrigerator. The retraction angle selected according to the invention can also serve to increase the efficiency, but also to reduce the humidity of the room air of the domestic refrigerator according to the invention. The basis for a relatively highly efficient function of an evaporator is preferably a relatively good heat transfer at the evaporator surface / air interface. In practice, this transition is inhibited by condensate, which is present in the form of large-scale, slowly draining drops of water. These drops of water can significantly reduce the heat transfer and thereby reduce the active surface of the evaporator. In addition, in the case of whereabouts or a relatively slow-running condensate, the risk of icing of the water droplets on the surface of the evaporator, so that the active, available for cooling surface of the evaporator is at least temporarily reduced and the efficiency of a household cooling appliance decreases. A targeted avoidance of crosslinking and / or Verreifung on the surface of the evaporator would provide a durable and relatively high condensation rate on the evaporator and thus at least reduce the problem of unwanted condensation, for example, designed as glass plates shelves. An influencing factor for the described increase in efficiency is the wetting behavior of the capacitor surface, namely the contact angle and in particular the retraction angle. The contact angle for water droplets of the coated surface of the evaporator conventional household refrigerators is about 80-85 °, and thus at the limit of hydrophobic properties.

Essentially, the angle of retraction alone is decisive for improved, optimized runtime behavior. Surfaces which exhibit a permanently increased condensation efficiency, in particular due to two mechanisms, provide for as large an area as possible an exposed capacitor area.

A first mechanism intervenes shortly after the nucleation of the condensate. Regardless of the design of the surface properties, these small drops have a relatively unfavorable mass / wetting surface. Ratio does not allow the ability to drain from the condenser surface solely by gravity. This becomes possible only when the smallest drops of water combine to form larger drops of water. Of particular importance here is the reduction of the wetted surface during the merger, so that the above-mentioned relationship shifts in favor of a possible water droplet flow. If the wetted area is not significantly reduced during the merger, it can not be drained. Decisive for this behavior is above all the retreat angle of the surface.

In the context of a second mechanism, a water droplet has set in motion, so there is a possibility that it runs relatively fast in almost perfect spherical shape, or moves at a slow speed under the tightening of a more or less long trace track. The latter case should be avoided as there is a risk of icing. Also here the retraction angle of the condenser surface controls this drainage behavior. If the value is set correspondingly high, then not only a relatively fast and, above all, as complete as possible drainage of the water droplet can be ensured, but also relatively small, not yet flowable water droplets lying in the discharge lane can be included.

Conventional evaporators are coated so that their surfaces give a retraction angle of about 30 °. Due to the properties according to the invention of the surfaces or of the further surface, the improved dripping behavior of the corresponding surface results.

According to a preferred embodiment of the household appliance according to the invention, the part of the surfaces and / or the further surface is provided with a coating. A suitable coating is, for example, a plasma coating, preferably a low-pressure plasma coating, a nano-coating, a powder coating and / or a coating. The coating may advantageously be produced by a wet chemical process, for example by dip coating or spray coating, or by a vapor deposition process, eg based on low pressure or atmospheric pressure plasma. The coating comprises, in particular, a silicon-organic hybrid material. Suitable materials for the coating are preferably materials from the group of alkyl-functional or partially fluorinated-alkyl-functional polymers and hybrid polymer coatings having the same functionality. In the case of the polymers, these may be, for example, polyethylenes, polypropylenes or the like, in the case of the hybrid materials layers based on organosilicon, organoaluminum or zirconium organic compounds.

In particular, the property according to the invention of the surfaces or of the further surface can be achieved by means of plasma coatings or nanocoatings. It is also advantageous if the retraction angle properties according to the invention remain relatively long under permanent exposure to moisture. It is possible that e.g. due to the smallest hydrolysis effects in the coating, a significant decrease in the withdrawal angle and thus a loss of the condensation-enhancing properties arises. Therefore, low-pressure plasma-deposited layers are particularly suitable as a coating.

According to a preferred embodiment of the household appliance according to the invention, the coating has a thickness of at most 10μηι, in particular a maximum of 2μηι, preferably of at most 500nm. Because of this relatively thin coating, the heat resistance additionally produced by the coating can be kept relatively low, as a result of which the above-described increase in efficiency of the household appliance according to the invention designed as a domestic refrigerating appliance is only relatively poorly, if not negligibly, worsened. Suitable for the reaction, for example, layers or compounds prepared from silicon-organic precursors, which have a very low proportion of polar bonds. Furthermore, the material per se should have a relatively high stability with respect to the formation of polar bonds. These can arise, for example, when nonpolar groups or polar bonds are broken or destroyed by environmental factors (eg, by hydrolysis). A suitable material is Greblon Ceran, for example, which is used as a coating of cookware. Greblon is a registered trademark. The coating may also include a pattern and / or a label.

The household appliance according to the invention can also be designed as a domestic dishwasher, which comprises a washing container with the surfaces which delimit the interior, wherein the interior is provided for loading items to be washed. The items to be washed include e.g. Dishes and / or cutlery. The washing container comprises in particular two side walls, a ceiling and a rear wall. Preferably, only the rear wall and the two side walls have said properties. Due to the selected retreat angle, the drying of the items to be washed can be improved during a drying step carried out by the household dishwasher.

The domestic dishwasher may comprise a water tank, which is arranged behind the surface of the washing container, which is at least partially formed such that water droplets forming there have a retraction angle of at least 60 °, in particular of at least 70 °, preferably at least 80 °. This part of the washing container in particular has a surface actively cooled by the water in the water tank. The surface in question is in particular the surface of the rear wall of the washing container. The domestic appliance according to the invention can also be designed as a condensation drying apparatus which has the heat exchanger with the surface. The heat exchanger is e.g. a crossflow heat exchanger. The household appliance according to the invention designed as a condensation drying apparatus preferably comprises a heat pump which has a refrigerant circuit with an evaporator designed as the heat exchanger.

Condensation drying devices are intended to dry wet or damp laundry. The laundry can be stored in a e.g. horizontally rotating drum and is thereby constantly circulated during operation. Heated air is passed into or through the laundry to dry it.

In condensation dryers, the air inside the condensation dryer is in a largely closed loop arranged. The initially cool air is heated, which reduces their relative humidity. The heated air is passed through the laundry located in the drum, for example, blown and absorbs moisture caused by evaporation of the laundry. The example arranged below the drum heat exchanger extracts moisture from the air within the condensation dryer by cooling the air at the heat exchanger surface. As a result, water droplets can form on the surface of the heat exchanger or of the evaporator. Due to the property according to the invention of at least part of the surface of the heat exchanger, these water droplets can flow off relatively quickly. Embodiments of the invention are illustrated by way of example in the accompanying schematic drawings. Show it:

1 shows a household cooling device with a coolable inner container in a perspective view,

2 a refrigerant circuit of the household refrigerating appliance,

3 is a side view of a rear wall of the household refrigerator,

Fig. 4 is designed as a Rollbond evaporator evaporator of

Household refrigerator,

5 is a perspective view of a domestic dishwasher, FIG. 6 is a schematic representation of the household dishwasher,

7 is a schematic representation of a condensation drying apparatus,

Fig. 8 is an illustration for illustrating the contact angle of a

Drop of water on a surface, and

Fig. 9 is an illustration for illustrating the retreat angle of a water droplet on a surface.

Fig. 1 shows a household refrigerating appliance 1 in perspective as an example of a domestic appliance comprising a plurality of walls bounding an interior space, the walls comprising surfaces facing the interior space.

In the case of the present embodiment, the household refrigerator 1 comprises a heat-insulated body with an inner container 2, which limits a coolable interior 3. The inner container 2 comprises in particular a rear wall 4 and two Side walls 5 and a ceiling 6. The inner container 2 forms the coolable interior 3 facing surfaces 4a, 5a, 6a. In particular, the side walls 5 each have a surface 5a, the rear wall 4 has a surface 4a and the top 6 has a surface 6a. The coolable interior 3 is provided for storing food, not shown.

In the case of the present exemplary embodiment, the household refrigerating appliance 1 has a pivotable door leaf 7 for closing the coolable interior 3. When the door leaf 7 is open, the coolable interior 3 is accessible. On the direction towards the coolable interior 3 side of the door leaf 7 a plurality of door racks 7a are arranged for storing food in the case of the present embodiment. In particular, a plurality of shelves 8 are arranged for storing food in the coolable interior 3, and in particular a drawer 9, in which food can be stored, is arranged in the lower region of the coolable interior 3.

The domestic refrigerator 1 comprises a refrigerant circuit 20 shown in FIG. 2 for cooling the coolable interior 3. In the case of the present embodiment, the refrigerant circuit 20 of the coolable interior 3 comprises a compressor 21, a condenser 22 downstream of the compressor 21, a condenser 22 downstream Throttling device 23, which is designed in particular as a throttle or capillary tube, and an evaporator 24, which is arranged between the throttle device 23 and the compressor 21.

In the case of the present embodiment, the household cooling device 1 comprises a gutter 10 to collect condensate or water droplets forming 1 1, to collect and preferably from the coolable interior 3 to the outside in a non-illustrated evaporation tray of the household refrigerator 1. The gutter 10 is formed, for example, on the rear wall 4, so that the forming on the surface 4a of the rear wall 4 drops of water 1 1 can run into the gutter 10. 3 shows a sectional view of a side view of a portion of the rear wall 4 with the gutter 10th In the case of the present embodiment, the evaporator 24 is arranged behind the surface 4a of the rear wall 4, in particular foamed behind the surface 4a of the rear wall 4 in the rear wall 4. The surface 4a of the rear wall 4 represents in particular an actively cooled surface. In the case of the present embodiment, the condensation rate, ie the amount of condensate per time (or condensation surface) on the surfaces 4a, 5a, 6a of the inner container 2, in particular the surface 4a of the rear wall 4 to improve even at relatively high surface temperatures, in the case of the present embodiment, at least part of the surface 4a of the rear wall 4, if not the complete surface 4a of the rear wall 4 designed such that forming on this part of the surface 4a Water drops 1 1 have a retraction angle 9 _R of at least 60 °, in particular at least 70 ° and preferably at least 80 °. Also, the surfaces 5a of the side walls 5 may have these properties.

In the case of the present embodiment, the evaporator 24 may also be formed as a planar evaporator and in particular as a roll bond evaporator 24a. The designed as a planar evaporator evaporator 24 may be arranged in particular within the coolable interior 3.

The Rollbond evaporator 24a is in the case of the present embodiment, spaced from the rear wall 4 of the inner container 2 attached thereto. The rollbond evaporator 24 may, however, be e.g. also be attached to one of the side walls 5 spaced from this. He may also extend partially over at least part of the ceiling 6 of the inner container 2. A side view of the rollbond evaporator 24a is shown in FIG. Fig. 4 also shows a part of the rear wall 4 of the inner container 2 in a sectional view.

The rollbond evaporator 24a has a plate-like or planar shape and comprises surfaces 25 which run essentially parallel to the rear wall 4 and to the corresponding side wall 5. In the case of the present embodiment, below the Rollbond evaporator 24a, the gutter 10 is provided to collect condensate of the Rollbond evaporator 24a, collect and preferably to conduct outside in the not shown evaporation tray of the household refrigerator 1. In the case of the present exemplary embodiment, in order to improve the condensation rate on at least one of the surfaces 25 of the rollbond evaporator 24a, in the case of the present exemplary embodiment at least a part of at least one of the surfaces 25 is designed such that water droplets 1 forming on this part of the surface 25 are formed 1 have a retraction angle 9 _R of at least 60 °, in particular at least 70 ° and preferably at least 80 °.

In order for the said part of the surface 4a of the rear wall 4 or the said part of the surface 25 of the roll bond evaporator 24a to have said property, in the case of the present exemplary embodiment the surface 4a or at least the said part of the surface 4a of the rear wall 4 and / or The surface 25 or the said part of the surface 25 of the roll bond evaporator 24a is provided with a coating 12, 12a.

The coating 12, 12a is embodied, for example, as a plasma coating, a nano-coating or as a powder coating. It can also be designed as a paint job. The coating 12, 12a was produced in particular by means of a low-pressure plasma method. In order for the coating 12 to have said property with respect to the water drops 11, it preferably comprises a silicon-organic hybrid material. A suitable material is Greblon Ceran, for example, which is used as a coating of cookware. Greblon is a registered trademark. Suitable materials for the coating 12, 12a include, for example, materials from the group of alkyl-functional or partially fluorinated-alkyl-functional polymers and hybrid polymer coatings having the same functionality. In the case of the polymers, these may be, for example, polyethylenes, polypropylenes or the like, in the case of the hybrid materials layers based on organosilicon, organoaluminum or zirconium organic compounds. The coating 12 is preferably relatively thin. It is in particular at most 10μηι, in particular at most 2μηη and preferably at most 500nm thick.

The coating 12 may also include a pattern and / or a label. The coating 12a may e.g. be applied directly to the surface 25 of the roll bond evaporator 24a. The Rollbond evaporator 24a may also be painted, with the coating 12a applied to the paint.

Figures 5 and 6 show a domestic dishwasher 51 as a further example of a domestic appliance comprising a plurality of walls defining an interior, the walls comprising surfaces facing the interior.

FIG. 5 shows the domestic dishwasher 51 in a perspective view, and FIG. 6 shows the household dishwasher 51 in a schematic representation.

The domestic dishwasher 51 has a washing container 52 which limits an interior space 53 for receiving items to be washed. The household dishwasher 51 includes e.g. a plurality of dish containers, arranged one above the other and designed as baskets 54, in which the items to be washed can be arranged. The items to be washed are, in particular, cutlery and / or crockery, such as, for example, plates 55.

The rinsing container 52 comprises, in particular, two side walls 56, a rear wall 57, a cover 65 and a bottom 58 which have surfaces 56a, 57a facing the interior 53.

The rinsing container 52 can be closed by means of a relative to a horizontal axis pivotable door leaf 59, as is usual. When the door leaf 59 is open, the crockery baskets 54 can be pulled out of the washing container 52 in order to at least facilitate loading and unloading of the crockery baskets 54. In the washing container 52, for example, spray devices for applying the items to be washed are arranged with a liquid, which is usually referred to as rinsing liquor. The spray devices are designed, for example, as spray arms 60 mounted rotatably. The liquid may, for example, from a below the bottom 58 of the washing container 52nd arranged circulating pump 61 are conveyed via liquid supply lines to the spray arms 60. The circulating pump 61 is driven, for example, by means of an electric drive not shown in detail, in particular by means of its electric motor. The bottom 58 comprises a drain 63 so that the liquid within the washing container 52 can reach the circulation pump 61.

In the case of the present exemplary embodiment, the household dishwasher 51 comprises a water container 62, which is arranged in particular behind the rear wall 57 of the washing container 52 and, in particular, is in contact with it flatly. The water tank 62 is provided for holding water and / or liquid used for rinsing the items to be washed. The surface 57a of the rear wall 57 represents, in particular, an actively cooled surface.

During operation of the domestic dishwasher 51, condensate in the form of water drops 66 may form on the surfaces 56a, 57a of the washing container 52 facing the interior 53, in particular the rear wall 57 and the side walls 56.

In the case of the present embodiment, the condensation rate, ie the amount of condensate per time (or condensation surface) on the surfaces 56a, 57a of the side walls 56 and the rear wall 57 of the washing container 52, in particular the surface 57a of the rear wall 57 even at relatively high surface temperatures In the case of the present embodiment, at least a part of the surface 57a of the rear wall 57, if not the entire surface 57a of the rear wall 57 (and / or the side walls 56) is made such that water droplets forming on this part of the surface 57a are formed 66 have a retraction angle 9 _R of at least 60 °, in particular at least 70 ° and preferably at least 90 °.

In order for the said part of the surface 57a of the rear wall 57 to have said property, in the case of the present embodiment the surface 57a or at least the said part of the surface 57a of the rear wall 57 is provided with a coating 64. The coating 64 is designed, for example, as a plasma coating, a nano-coating or as a powder coating. It can also be designed as a paint job. It was produced in particular by means of a wet-chemical process. In order for the coating 64 to have said property with respect to the water droplets 63, it preferably comprises a silicon organic hybrid material. A suitable material is Greblon Ceran, for example, which is used as a coating of cookware. Greblon is a registered trademark. Suitable materials for the coating include, for example, materials from the group of alkyl-functional or partially fluorinated-alkyl-functional polymers and hybrid polymer coatings having the same functionality. In the case of the polymers, these may be, for example, polyethylenes, polypropylenes or the like, in the case of the hybrid materials layers based on organosilicon, organoaluminum or zirconium organic compounds.

The coating 64 is preferably relatively thin. In particular, it is at most 10 μm, in particular not more than 2 μm, and preferably not more than 500 nm thick.

The coating 64 may also include a pattern and / or a label.

Fig. 7 shows a condensation drying apparatus 71 as an example of a household appliance with a heat exchanger.

The condensation drying apparatus 71 has a housing 72 within which a laundry drum 73 provided for receiving laundry is rotatably mounted with respect to a horizontal axis. In the operation of the condensation drying apparatus 71, the laundry drum 53 can be rotated by means of a non-illustrated drive with respect to the horizontal axis.

The condensation drying apparatus 71 comprises a door leaf 74 which can be pivoted relative to the housing 72 and openly makes an opening in the housing 72 accessible so that the laundry drum 73 can be loaded or unloaded with the laundry.

Within the housing 72, a channel system 75 is provided which extends partially below the laundry drum 73. Within the channel system 75 is a Circulation pump 76 is arranged, which is adapted to convey air within the channel system 75 such that it blows in the direction of arrows 77. In particular, the air is conveyed through the laundry drum 73, in particular from the rear side of the condensation drying apparatus 71 in the direction of the front side of the condensation drying apparatus 71 which surrounds the door leaf 74.

In particular in the area of the door leaf 74, an exchangeable lint filter 78 can be provided within the channel system 75.

In operation of the condensation drying apparatus 71, the air is introduced into the laundry drum 73 prior to entry into e.g. heated by means of an electric heater, not shown, so that this heated air is able to dry the laundry in the laundry drum 73. The air enriched in moisture thereby flows out of the laundry drum 73 and is cooled by means of a heat exchanger arranged inside the channel system 75 and in particular below the laundry drum 73, whereby moisture is withdrawn from the air. This moisture settles on a surface of the heat exchanger as drops of water, which are collected by means of a arranged below the heat exchanger water collecting tray 79. The heat exchanger is e.g. a crossflow heat exchanger. In the case of the present embodiment, the condensation drying apparatus 71 has a heat pump 80 in the form of a refrigerant circuit. The heat pump 80 or the refrigerant circuit comprises a compressor 81, a condenser 82 downstream of the compressor 81, a throttle device connected downstream of the condenser 82, and an evaporator 84, which is arranged between the throttle device and the compressor 81.

The evaporator 84 and the condenser 82 are arranged within the channel system 75 and in particular below the washing drum 73. The condenser 82 is connected downstream of the evaporator 84 in the direction of the arrows 77, ie in the direction of the air flow of the air, and heats the air before it enters the laundry drum 73. The condenser 82 thus acts as a heater for heating the heating element in the case of the present exemplary embodiment Air. The evaporator 84 is provided to cool the heated and moisture-enriched air conveyed from the laundry drum 77 to extract moisture therefrom. The evaporator 84 has a surface 85, on which this moisture beats down as drops of water, which are collected by means of the arranged below the heat exchanger designed as an evaporator 84 water collecting tray 79

In order for the drops of water to drip better from the surface 85 of the heat exchanger or evaporator 84, i. In order to improve the condensation rate, ie the amount of condensate per time (or condensation surface) on the surface 85 of the heat exchanger or the evaporator 84, in the case of the present embodiment at least a part of the surface 85 of the heat exchanger or the evaporator 84, if not the entire surface 85 of the heat exchanger or the evaporator 84 carried out such that on this part of the surface 85 forming water droplets have a retreat angle of at least 60 °, in particular at least 70 ° and preferably at least 90 °.

In order for the said part of the surface 85 of the heat exchanger or the evaporator 84 to have said property, in the case of the present embodiment the surface 85 or at least the said part of the surface 85 of the heat exchanger or evaporator 84 is provided with a coating 86.

The coating 86 is embodied, for example, as a plasma coating, a nano-coating or as a powder coating. It can also be designed as a paint job. It was produced in particular by means of a wet-chemical process. In order for the coating 86 to have the said property with respect to the water droplets, it preferably comprises a silicon-organic hybrid material. A suitable material is Greblon Ceran, for example, which is used as a coating of cookware. Greblon is a registered trademark. Suitable materials for the coating include, for example, materials from the group of alkyl-functional or partially fluorinated-alkyl-functional polymers and hybrid polymer coatings having the same functionality. In the case of the polymers, these may be, for example, polyethylenes, polypropylenes or the like, in the case of the hybrid materials layers based on organosilicon, organoaluminum or zirconium organic compounds. The coating 86 is preferably relatively thin. In particular, it is at most 10 μm, in particular not more than 2 μm, and preferably not more than 500 nm thick.

As already stated, there are, in addition to the retraction angle 9 _R, inter alia the contact angle θ _κ . Essentially, the retraction angle 9 _R alone is decisive for an improved optimized drainage behavior.

The retraction angle θ _R and the contact angle θ _{κ of} a water droplet surface 90 shown in FIGS. 8 and 9 can be determined using a measuring device, which is known in principle to a person skilled in the art and not shown. For the measurement of the contact angle 9 _R , for example, a water droplet 91 of a certain volume shown in FIG. 8 can be placed on the surface 90 and the image of the water droplet 91 can be electronically evaluated after a certain time, eg after 5 seconds. In the case of the example shown in Figure 8, the surface 90 is formed such that the contact angle θ _{κ of} the water droplet 91 is approximately 75 °. The surface 90 is, for example, the surface 4 a of the rear wall 4 of the inner container 2 of the household refrigerator 1, the surface 25 of the Rollbond evaporator 24 a, the surface 57 a of the rear wall of the washing container 52 of the domestic dishwasher 51 or the surface 85 of the evaporator 84 of the condensation drying apparatus 71.

The retraction angle 9 _R can be determined, for example, during a suction of the water droplet 91 at a predetermined speed of, for example, 60 μΙ / min. This is illustrated in FIG. 9, which shows the water droplet 91 decreasing due to the absorption. For sucking up the water droplet 91, for example, a syringe needle 92 is used. FIG. 9 illustrates a retraction angle 9 _R for the water droplet 91 of at least 60 °. LIST OF REFERENCE NUMBERS

1 household refrigerator

2 inner containers

3 coolable interior

4 rear wall

4a surface

5 side walls

5a surface

6 ceiling

6a surface

7 Türbaltt

7a door rack

8 shelves

9 drawer

10 gutter

1 1 drops of water

12 coating

12a coating

20 refrigerant circuit

21 compressors

22 liquefier

23 throttle device

24 evaporator

24a Rollbond evaporator

25 surfaces

51 household dishwasher

52 washing containers

53 interior

54 baskets

55 plates

56 side walls 56a surface

57 rear wall

57a surface

58 floor

59 door leaf

60 spray arms

61 circulation pump

62 water tank

63 Procedure

64 coating

65 ceiling

66 drops of water

71 Condensation drying device

72 housing

73 laundry drum

74 door leaf

75 channel system

76 circulation pump

77 arrows

78 lint filter

79 Water catch tray

80 heat pump

81 compressors

82 liquefier

84 evaporator

85 surface

86 coating

90 surface

91 drops of water

92 spike

θ _κ contact angle

e _R retreat angle

92 spike

Claims

Home appliance,

comprising a plurality of walls (2, 4, 5, 6, 52, 56, 57, 58, 65) delimiting an interior space (3, 33), the surfaces (4a, 5a, 56a) facing the interior (3, 33), 57a), of which at least a part of the surfaces (4a, 5a, 56a, 57a) is formed such that water droplets (11, 66) forming on this part of the surfaces have a retraction angle (9 _R ) of at least 60 ° , and / or in which inside the interior (3) a component (24a) is arranged as a component of the domestic appliance (1), which has a further surface (25), wherein at least a part of the further surface (25) is designed such that on this part of the further surface (25) forming water droplets (1 1) have a retreating angle (9 _R ) of at least 60 °, or

- comprising a heat exchanger, in particular an evaporator (24, 84) of a refrigerant circuit (20, 80) having a surface (25, 85), wherein at least a part of the surface (25, 85) of the heat exchanger is designed such that on this part of the surface (25, 85) of the heat exchanger forming water droplets (1 1) have a retreating angle (9 _R ) of at least 60 °.

Domestic appliance according to claim 1, characterized in that the part of the surfaces (4a, 5a, 56a, 57a) and / or the further surface (25) and / or the surface (25, 85) of the heat exchanger is designed such that on this Part of the surfaces (4a, 5a, 56a, 57a) or the further surface (25) or the surface (25, 85) of the heat exchanger forming water droplets (12, 66) has a retraction angle (9 _R ) of at least 70 °, preferably at least 80 °.

Domestic appliance according to claim 1 or 2, characterized in that the walls of the inner space (3, 53) comprise two side walls (5, 56), a rear wall (4, 57) and a ceiling (6, 65), wherein at least a part of Surfaces (4a, 5a, 56a, 57a) of at least one of the side walls (5, 56) and / or the rear wall (4, 57) is formed such that there forming water droplets (1 1, 66) a retreat angle (GR) of at least 60 °, of at least 70 °, preferably of at least 80 °.

Domestic appliance according to one of claims 1 to 3, characterized in that the part of the surface (4a, 5a, 56a, 57a) and / or the further surface (25) and / or the surface (25, 85) of the heat exchanger with a coating (12, 12a, 64, 86), in particular provided with a plasma coating, a nano-coating, a powder coating and / or a coating, which was produced in particular by means of a wet-chemical process and / or in particular comprises a silicon organic hybrid material and / or in particular a Material from the group of alkyl-functional or partially fluorinated-alkyl-functional polymers comprises and / or is in particular designed as a hybrid polymer coating, in particular polyethylenes, and / or polypropylenes identifies and / or based on organosilicon, organoaluminum or organozirconium basis.

Domestic appliance according to claim 4, characterized in that the coating (12, 12a, 64, 86) has a thickness of at most 10μηι, in particular a maximum of 2μηι, preferably of at most 500nm.

Domestic appliance according to claim 4 or 5, characterized in that the coating (12, 12a, 65) comprises a pattern and / or a label.

Domestic appliance according to one of claims 1 to 6, characterized in that it is designed as a domestic refrigeration appliance (1) having a refrigerant circuit (20) with an evaporator (24, 24a) for cooling the interior (3) and a heat-insulated body with a the inner surface (4a, 5a) having inner container (22), wherein the interior is provided for storing food, and / or wherein the heat exchanger as the evaporator (24, 24a) is formed.

Domestic appliance according to claim 7, characterized in that the evaporator (24) behind the surface (4a) of the inner container (2) is arranged, which is at least partially designed such that there forming water droplets (1 1) a Retraction angle (9 _R ) of at least 60 °, in particular of at least 70 °, preferably of at least 80 °.

Domestic appliance according to claim 7 or 8, characterized in that the inner container (2) has at least one vertically extending wall (4) and the evaporator as a planar evaporator (24a) which is spaced from the vertical wall (4) within the coolable Interior (3) is arranged and which has a surface (25) which is at least partially formed such that there forming water droplets (1 1) a retraction angle (9 _R ) of at least 60 °, in particular at least 70 °, preferably of at least 80 °.

10. Household appliance according to one of claims 1 to claim 6, characterized in that it is designed as a domestic dishwasher (51), which comprises a washing compartment (52) with the surfaces (56 a, 57 a) which limits the interior, wherein the interior (53) is provided for loading items to be washed (55).

Domestic appliance according to claim 10, characterized in that it comprises a water tank (62) which is arranged behind the surface (57a) of the washing container (52), which is at least partially formed such that there forming water drops (66) has a retreat angle (9 _R ) of at least 60 °, in particular of at least 70 °, preferably of at least 80 °.

12. Household appliance according to one of claims 1 to 6, characterized in that it is designed as a condensation drying apparatus (71) having the heat exchanger with the surface (86).

13. Household appliance according to claim 12, characterized by a heat pump (80) having a refrigerant circuit with a heat exchanger formed as the evaporator (85).