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.
According to a first embodiment the channel closure means is configured as a water-soluble film 1a, which is drawn over the end face of the tube at the outlet end 12 of the defrost water channel.
According to a third embodiment illustrated in
Alternatively a plug or tab 1d—as likewise shown in FIG. 5—can also be inserted into a separate channel section piece 3b according to the fourth embodiment. The channel section piece 3b shown in
According to
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.
Number | Date | Country | Kind |
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102008040430.6 | Jul 2008 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2008/067946 | 12/18/2008 | WO | 00 | 1/5/2011 |