US20110107783A1

US20110107783A1 - Channel closure means for a defrosting water channel of a refrigeration unit, defrosting water channel of a refrigeration unit, and refrigeration unit

Info

Publication number: US20110107783A1
Application number: US13/002,655
Authority: US
Inventors: Thomas Bischofberger; Martin Buchstab; Hans Ihle
Original assignee: BSH Bosch und Siemens Hausgeraete GmbH
Current assignee: BSH Hausgeraete GmbH
Priority date: 2008-07-15
Filing date: 2008-12-18
Publication date: 2011-05-12
Also published as: WO2010006662A1; RU2011101447A; EP2313720A1; EP2313719A2; WO2010007044A3; ES2394993T3; RU2499206C2; CN102099643A; DE102008040430A1; EP2313719B1; WO2010007044A2

Abstract

A channel closure means for a defrosting water channel of a refrigeration unit, such as a NoFrost refrigeration unit, is provided, wherein the channel closure means is water-soluble. Further, a defrosting water channel of a refrigeration unit is provided, wherein the defrosting water channel includes a channel closure means. In addition, a refrigeration unit, such as a NoFrost refrigeration unit is provided, wherein the refrigeration unit has a defrosting water channel.

Description

The invention relates to a channel closure means for a defrost water channel of a refrigeration unit, particularly of a NoFrost refrigeration unit, a defrost water channel of a refrigeration unit and a refrigeration unit, particularly a NoFrost refrigeration unit.
In a refrigeration unit of the abovementioned type the air is supplied by means of a circulating air system in the refrigeration compartment to an evaporator, which is in particular disposed outside the actual refrigeration compartment. Ice forms on the evaporator. The evaporator defrosts regularly, the defrost water being discharged by way of a defrost water channel into an evaporation tray. To prevent an inflow of ambient air by way of the defrost water channel into the refrigeration compartment or in the case of a NoFrost appliance into the evaporator chamber, a siphon for example is integrated in the defrost water channel.
This has the disadvantage that in particular before the refrigeration unit is brought into operation and up to the time when the siphon is full of water, ambient air and moisture can flow through the defrost water channel into the refrigeration compartment or to the evaporator and cause ice to form on the evaporator.
The object of the invention is therefore to prevent a flow of ambient air through a defrost water channel to an evaporator of a refrigeration unit, in particular until the water siphon is full of defrost water and carries out its function.
The object is achieved with a channel closure means for a defrost water channel of a refrigeration unit, particularly of a NoFrost refrigeration unit, wherein the channel closure means is water-soluble.
A refrigeration unit within the meaning of the invention can in particular be defrosted automatically and is for example a refrigerator, upright freezer or combined fridge/freezer or chest freezer. A NoFrost refrigeration unit within the meaning of the invention is a refrigeration unit, in which the evaporator is disposed outside the refrigeration compartment in an evaporator chamber and the cooling air is circulated by means of a fan between the evaporator chamber and refrigeration compartments. The evaporator of such a refrigeration unit can be defrosted by a defrosting heater.
The defrost water channel of the refrigeration unit transports defrost water produced in the refrigeration unit, particularly on the evaporator, to the exterior of the refrigeration unit, so that the defrost water can evaporate outside the refrigeration unit, in particular utilizing the waste heat from a compressor. The defrost water channel is for example a tube, hose or gutter and preferably opens into an evaporation tray, which is advantageously disposed above the compressor.
To prevent an inflow of ambient air by way of the defrost water channel into the refrigeration compartment or in the case of a NoFrost appliance into the evaporator chamber a siphon is preferably integrated in the defrost water channel. This fills with defrost water and then prevents the ingress of ambient air into the refrigeration compartment or in the case of a NoFrost appliance into the evaporator chamber.
An inventive channel closure means dissolves due to contact with water, in particular due to contact with defrost water of a refrigeration unit. It therefore seals off the defrost water channel of a refrigeration unit temporarily so that ambient air and moisture cannot flow through the defrost water channel, until it dissolves due to contact with water. The defrost water channel can therefore be closed off at least temporarily by means of the channel closure means.
The channel closure means is preferably configured as a film, in particular as a starch film. Alternatively the film can contain any other water-soluble material, e.g. organic materials such as saccharose and polysaccharose or inorganic materials, e.g. NaCl or other salts. The film does not have to be made entirely of the water-soluble material; it simply has to be ensured that the channel closure means becomes water-permeable on contact with water. It would also be conceivable to use a net or fabric structure, the mesh of which is closed with a water-soluble material. It is therefore conceivable, if not preferred, for residues of the film to remain in the defrost water channel, as long as they do not impede the discharging of the defrost water.
However any other channel closure means which can be used to close off the defrost water channel temporarily are also suitable. For example a plug or plate is also suitable, its geometry being tailored to the cross section of the defrost water channel in such a way that it can be used to close off the defrost water channel and being made of any water-soluble material. The abovementioned organic or inorganic water-soluble materials such as starch and salt are suitable for example. Such a plug is preferably held with a form fit or force fit in a section of the defrost water, its periphery being in contact in a sealing manner with the inner wall of the channel.
According to a first preferred embodiment the plug is configured as a tab, for example a tablet or pill, made at least essentially of a water-soluble organic or inorganic material. The tab preferably has a peripheral shape tailored to the cross section of the defrost water channel, particularly preferably being rounded, e.g. roughly spherical or ellipsoid or ring-shaped or plate-shaped.
According to another embodiment the plug is configured as a gas-filled blister, the outer skin of which is formed by a water-soluble film. The water-soluble film can be made of the abovementioned materials, e.g. starch. The gas is preferably air or nitrogen. This embodiment has the advantage that the blister can adjust to different cross-sectional shapes of defrost water channels and be easily introduced into these and be held therein with a form or in particular friction fit.
Should the dissolving material of the channel closure means leave residues in the defrost water, which could result in a biological growth in the evaporation tray where the defrost water collects, as a countermeasure a substance that inhibits biological growth can be placed in the evaporation region of the defrost water, e.g. salt or other suitable chemicals such as cationic tensides or the like. The substance preventing biological growth can also be a biocide, in particular a bactericide or fungicide. This substance can be secured in the defrost water tray in a small packet or as a tablet, so that the substance is released on contact with the defrost water.
It is however particularly advantageous to integrate a substance that prevents biological growth in the defrost water in the channel closure means.
Since the channel closure means comprises the substance, the substance is only activated when the biological growth actually has to be prevented due to the dissolving channel closure means. The channel closure means comprises the substance in tablet form for example, the tablets being secured in the channel closure means or said substance is integrated in the channel closure means in some other form. If the channel closure means is a tab, the substance inhibiting biological growth is preferably compressed into a tablet together with the water-soluble material.
The channel closure means can also feature a composite structure, the substance for example forming part of the channel closure means.
Alternatively the substance can be provided in the defrost water channel separately from the channel closure means, for example before and/or behind the channel closure means in the flow direction of the defrost water. The substance can also form the channel closure means or is an additional channel closure means temporarily closing off the defrost water channel.
The object is further achieved with a defrost water channel of a refrigeration unit, the defrost water channel comprising an inventive channel closure means for closing off the defrost water channel. Such a defrost water channel is closed off with the channel closure means until said channel closure means comes into contact with water and dissolves as a result. As soon as the channel closure means dissolves, defrost water can flow through the defrost water channel and be discharged to the exterior of the refrigeration unit.
The channel closure means is preferably disposed in the defrost water channel essentially perpendicular to the flow direction of the defrost water. The external geometry of the channel closure means here is essentially congruent to the internal geometry of the defrost water channel so that the channel closure means reliably seals the defrost water channel until it dissolves due to contact with water. The size of the required channel closure means is therefore essentially determined by the size of the defrost water channel, so that the channel closure means can be embodied as small and cost-effective. The defrost water channel can have any cross section but the preferred cross sections are round, square or oval.
The defrost water channel preferably comprises a siphon. It is particularly preferable for the channel closure means to be disposed behind the siphon in the flow direction of the defrost water. When the evaporator of the refrigeration unit is defrosted therefore the siphon fills with water first. Only after this does the channel closure means come into contact with the water and dissolve. Since the siphon is already full of defrost water, ambient air can no longer flow through the defrost water channel to the evaporator even after the channel closure means has dissolved. It is particularly preferable for the channel closure means to be disposed in the defrost water channel in such a manner that it dissolves completely, for example because it comes into contact with the water along its entire surface facing the water.
It is further preferable for the substance for preventing biological growth to be disposed in particular additionally in front of the siphon in the flow direction of the defrost water, so that it also acts on the water held in the siphon. The substance can be disposed in the defrost water channel for example in tablet form or in any other form, for example as a salt, gel or liquid. Alternatively or additionally the channel closure means can likewise comprise the substance.
The siphon can be configured for example as a tubular siphon, in other words having a U-shaped tube, the lower bend of which always remains full of defrost water, thereby preventing the ingress of ambient air into the evaporator chamber. This configuration is particularly simple to manufacture.
Alternatively the siphon can also be configured as a bottle, cup, baffle or bell siphon. Particularly preferable is an arrangement in which the tube of the defrost water channel opens from above into a cup-shaped vessel, the outlet opening of the defrost water channel being disposed as far below the cup edge as possible, so that defrost water collecting in the cup closes off the outlet opening. Such a configuration is referred to as a cup or bottle siphon. It is particularly preferable for the cup to be disposed in the evaporation tray so that defrost water from the cup flows directly into it.
According to the preferred embodiment a cover is disposed above the siphon, allowing water to overflow but slowing down the drying out of the siphon or cup.
The channel closure means can be introduced into the defrost water channel in different positions and in different ways, some of the preferred embodiments being illustrated below:
According to a first preferred embodiment the channel closure means is configured as a water-soluble film drawn over the outlet end of the defrost water channel. The film can be fixed there by moistening the end face at the outlet end of the tube and then pressing the film onto the end face.
According to a second preferred embodiment the channel closure means is configured as a water-soluble film in a channel section piece, which as a separate component forms part of the defrost water channel. The defrost water channel is therefore not a single piece but features a separate channel section piece, for example a piece of tube that is attached to the defrost water channel at its outlet for example or is inserted between the defrost water outlet of the refrigeration unit and the defrost water channel. The water-soluble film is already integrated in this channel section piece, in which process it can also be drawn over an end face of the channel section piece. This solution has the advantage that the defrost water channel can be manufactured in the conventional manner.
According to a third embodiment the channel closure means is configured as a plug, which is introduced into a hose or tube-type section of the defrost water channel. In order then to hold the plug in the defrost water channel with a friction fit, it is advantageous if the hose or tube-type section is at least slightly elastic, so that for example a spherical tab or a blister filled with gas can be pushed into it.
According to a fourth embodiment the channel closure means is preferably configured as a plug in a channel section piece, which as a separate component forms part of the defrost water channel. This solution has the advantage that the channel section piece can have for example a ring-shaped holder for the channel closure means, which is therefore held with a form fit and therefore particularly securely in the channel section piece. The channel section piece itself can be disposed in the same manner on the outlet or inlet end of the defrost water channel, as described above with reference to the channel section piece with integrated water-soluble film.
According to a fifth preferred embodiment the channel closure means is configured as a plug provided with at least one throughflow opening in the defrost water channel, the at least one throughflow opening being closed off with a water-soluble film. The channel closure means here can be configured for example as a perforated ring inserted into the defrost water channel. However a spherical plug is also possible, if it has at least one corresponding throughflow opening.
In the case of a cup siphon the plug can also be disposed in the manner of a sealing ring between the outlet end of the defrost water channel and the inner wall of the cup.
The object is further achieved with a refrigeration unit, particularly a NoFrost refrigeration unit, the refrigeration unit featuring an inventive defrost water channel. With such a refrigeration unit it is not possible for ambient air and moisture to flow through the defrost water channel to the evaporator even before the first defrosting of the evaporator.

The invention is described below by means of figures. The figures are only exemplary and do not restrict the general inventive concept.

FIG. 1 shows a schematic diagram of a section from a defrost water channel of a refrigeration unit.

FIG. 2 shows a schematic diagram of a defrost water channel of a refrigeration unit and an evaporator connected to the defrost water channel.

FIG. 3 shows a schematic diagram of a cross-sectional view of an arrangement consisting of a defrost water channel, evaporation tray and compressor at the rear of a refrigeration unit, having a channel closure means according to the abovementioned first embodiment.

FIG. 4 shows a schematic diagram of a cross-sectional view of an arrangement consisting of a defrost water channel, evaporation tray and compressor at the rear of a refrigeration unit, having a channel closure means according to the abovementioned second embodiment.

FIG. 5 shows a schematic diagram of a cross-sectional view of an arrangement consisting of a defrost water channel, evaporation tray and compressor at the rear of a refrigeration unit, having a channel closure means according to the abovementioned third embodiment.

FIG. 6 shows a cross-sectional diagram of an arrangement having a defrost water channel and evaporation tray on the rear wall of a refrigeration unit, having a channel closure means according to the abovementioned fourth embodiment.

FIG. 7 shows a cross-sectional diagram of an arrangement having a defrost water channel and evaporation tray on the rear wall of a refrigeration unit, having a channel closure means according to the abovementioned fifth embodiment.

FIG. 1 shows a schematic diagram of a section from a defrost water channel 2 of a refrigeration unit. A channel closure means 1 is disposed in an in particular separate tube part 3 of the defrost water channel 2 to close the defrost water channel 2 off against the ingress of ambient air and moisture, until it comes into contact with water and dissolves. The channel closure means 1 comprises a substance 4 preventing biological growth, in tablet form here, which is integrated in the channel closure means 1. When the channel closure means 1 comes into contact with defrost water, the tablet 4 dissolves so that the substance preventing biological growth is washed into the evaporation tray together with the residues of the channel closure means 1, where it prevents the residues becoming a breeding ground for bacteria or the like. The arrows show the flow direction F of the defrost water schematically. The defrost water channel 2 has an essentially oval cross section, so the channel closure means 1 also has an oval cross section and the outer periphery of the channel closure means 1 corresponds to the inner periphery of the defrost water channel 2. The channel closure means 1 therefore seals the defrost water channel 2 off against ambient air and moisture flowing counter to the flow direction F into the defrost water channel, so that ambient air or moisture cannot flow through the defrost water channel 2 counter to the flow direction F to the evaporator 6 (see FIG. 2) and cause ice to form thereon.
FIG. 2 shows a schematic diagram of a further embodiment of a defrost water channel 2 of a refrigeration unit and an evaporator 6, to which the defrost water channel 2 is connected. Such an evaporator 6 is disposed for example on the interior face of the rear wall of a refrigeration unit, for example a refrigerator or upright or chest freezer, or for example below the compartments or drawers of a refrigerator or upright freezer. In particular in a NoFrost appliance the evaporator 6 is disposed in an evaporator chamber of the refrigeration unit that can be heated separately. During operation of the refrigeration unit the moisture from the interior of the refrigeration unit condensing on the evaporator 6 turns to ice. Periodic heating of the evaporator 6 causes the moisture to melt and flow as defrost water through the defrost water channel 2 in the flow direction F into an evaporation tray outside the refrigeration unit. The defrost water channel 2 has a U-shaped siphon 5. The channel closure means 1 is disposed behind the siphon 5 in the flow direction F of the defrost water so that it does not come into contact with the defrost water and dissolve until the siphon 5 fills up. It is therefore not possible at any time for ambient air or moisture to flow through the defrost water channel 2 counter to the flow direction F to the evaporator 6 and cause ice to form thereon. A tablet containing a substance 4 preventing biological growth is also disposed in the siphon.
FIG. 3 shows a schematic diagram of the insulated wall 7 of a refrigeration unit. In the refrigeration unit defrost water collects in the defrost water guide 8 when the evaporator is defrosted to be discharged through a passage 9 out of the refrigeration unit. The defrost water then flows through a drain channel 2 configured as a tube or hose and featuring a U-shaped siphon 5. At its outlet end 12 the defrost water channel opens into an evaporation tray 10, which is disposed at least partially above a compressor 11, in order to utilize the latter's waste heat to evaporate the defrost water.
According to a first embodiment the channel closure means is configured as a water-soluble film 1 a, which is drawn over the end face of the tube at the outlet end 12 of the defrost water channel.
FIG. 4 shows a similar arrangement to the one in FIG. 3, with the channel closure means here integrated as a film 1 b in a separate channel section piece 3 a, which is inserted between the siphon 5 and an end tube piece 14 of the defrost water channel. The channel section piece 3 a can in particular be pushed onto the tube of the siphon and the tube piece 14 or be screwed or attached by adhesive to these.
According to a third embodiment illustrated in FIG. 5 the channel closure means is configured as a plug in the form of a roundish tab 1 c. The tab 1 c is pushed into the defrost water channel in a simple manner from the latter's outlet end 12 and held therein with a friction fit.
Alternatively a plug or tab 1 d—as likewise shown in FIG. 5—can also be inserted into a separate channel section piece 3 b according to the fourth embodiment. The channel section piece 3 b shown in FIG. 5 is disposed in front of the siphon 5 in the flow direction. This has the disadvantage that the plug 1 d in some circumstances dissolves before the siphon is full of water. This means advantageously that any biocide or salt contained in the plug reaches the water retained in the siphon and prevents biological growth there.
FIG. 6 shows an arrangement in which the defrost water channel 2 is provided with a cup siphon 15. A defrost water guide 8 passes through a passage 9 in the appliance insulation 7 here too. Connected to this is a defrost water channel 2, which opens downward into a cup-type vessel 17 at its outlet end 16. The cup 17 is disposed in an evaporation tray 10 and covered at the top with a cap 18, which protects the siphon 15 against drying out.
According to FIG. 6 the channel closure means is again configured as a plug 1 d, which here is however inserted into a separate channel section piece 3 b, which has a ring-shaped holder for the plug 1 d. The channel section piece 3 b is connected between the defrost water guide 8 and the defrost water channel 2.
FIG. 7 shows an arrangement of the channel closure means according to a fifth embodiment. Here a ring-shaped plug le is inserted between the outlet end 16 of the defrost water channel 2 and the cup 17 of the siphon 15, being provided with at least one through opening 19. This is initially closed off with a water-soluble film, which however dissolves on first contact with defrost water.
Alternatively instead of the ring-shaped plug le with through openings, it is also possible to provide a ring-shaped plug if without through openings, which dissolves in its entirety in water.
It is evident that the embodiments of the channel closure means shown in conjunction with a tubular siphon can also be used with a cup siphon and vice versa.

LIST OF REFERENCE CHARACTERS

1 Channel closure means
1 a-1 f Different embodiments of the channel closure means
2 Defrost water channel
3 Tube part of defrost water channel
4 Substance for preventing biological growth
5 Siphon
6 Evaporator
7 Appliance insulation
8 Defrost water guide
9 Passage through the appliance insulation
10 Evaporation tray
11 Compressor
12 Outlet end of defrost water channel
15 Cup siphon
16 Outlet end of defrost water channel
17 Cup-shaped vessel
18 Cover
19 Through opening
F Flow direction of defrost water

Claims

1-19. (canceled)

20. A channel closure means for a defrost water channel of a refrigeration unit, wherein the channel closure means is water-soluble.

21. The channel closure means of claim 20, wherein the refrigeration unit is a NoFrost refrigeration unit.

22. The channel closure means of claim 20, wherein the channel closure means is a film.

23. The channel closure means of claim 20, wherein the channel closure means is a plug that closes off the defrost water channel.

24. The channel closure means of claim 23, wherein the plug is a tab which includes an at least essentially water-soluble organic or inorganic material.

25. The channel closure means of claim 23, wherein the plug is a gas-filled blister, and wherein an outer skin of the gas-filled blister is formed by a water-soluble film.

26. The channel closure means of claim 20, wherein the channel closure means is a substance preventing biological growth.

27. A defrost water channel of a refrigeration unit, the defrost water channel comprising a channel closure means to close off the defrost water channel.

28. The defrost water channel of claim 27, wherein the defrost water channel is a siphon.

29. The defrost water channel of claim 28, wherein the channel closure means is disposed behind the siphon in a flow direction of defrost water.

30. The defrost water channel of claim 28, wherein the siphon is a tubular siphon.

31. The defrost water channel of claim 28, wherein the siphon is a cup siphon.

32. The defrost water channel of claim 27, wherein the channel closure means is a water-soluble film drawn over an outlet end of the defrost water channel.

33. The defrost water channel of claim 27, wherein the channel closure means is a water-soluble film in a channel section piece, and wherein the channel section piece is a separate component that is part of the defrost water channel.

34. The defrost water channel of claim 27, wherein the channel closure means is a plug that is introduced into one of a hose and a tube-type section of the defrost water channel.

35. The defrost water channel of claim 27, wherein the channel closure means is a plug in a channel section piece, and wherein the channel section piece is a separate component that is part of the defrost water channel.

36. The defrost water channel of claim 27, wherein the channel closure means is a plug with at least one throughflow opening in the defrost water channel, and wherein at least one throughflow opening is closed off with a water-soluble film.

37. The defrost water channel of claim 27, wherein a substance for preventing biological growth is disposed additionally in front of a siphon in a flow direction of defrost water.

38. A refrigeration unit, comprising a defrost water channel that has a channel closure means to close off the defrost water channel.

39. The refrigeration unit of claim 38, wherein the refrigeration unit is a NoFrost refrigeration unit.

40. The refrigeration unit of claim 38, wherein the defrost water channel opens into an evaporation tray.