COLD APPLIANCE
A cold appliance, such as a household refrigerator or freezer, comprising a cooling module (102) and a cabinet (101). The cabinet has been assembled from pre-foamed panels comprising two opposite side wall panels (1), a rear wall panel (4), a top part (2), and a bottom part (103), which are connected essentially perpendicular to each other e.g. by means of mechanical and/or or glue joints, and a door (6). The cabinet comprises a condensation preventing device (160) comprising a heat carrier tube (28, 160) being positioned at a front frame portion of the cabinet of the cold appliance, preferably adjacent to a part of the door (6). The heat carrier tube being filled with a heat carrier fluid, being closed and having a boiler portion (172), which is arranged in thermal contact with a heat generating means (32) of said cooling module for boiling the heat carrier fluid.
Latest AKTIEBOLAGET ELECTROLUX Patents:
The invention relates to a cold appliance.
BACKGROUND OF THE INVENTIONWhen manufacturing household cold appliances, such as refrigerators, comprising also pantries and wine coolers, and freezers, comprising also chest freezers, which are in the form of an openable cabinet and which are primarily adapted for domestic use but also can be used in for example restaurants and laboratories, hereinafter referred to as cold appliances for sake of simplicity, it is common practice to locate the production rather close to the customers, since the costs of transportation are considerable. This results in a comparatively large amount of production sites. It is desirable to rather have a few large production plants, and then distribute the products from these plants to the rest of the world. In this way it is possible to take advantage of large-scale benefits. For example, one problem associated with transporting cold appliances is that they represent bulky products containing a lot of air, which has to effect that the transport costs per weight unit will be considerable. It has been suggested to manufacture cold appliances in a modular fashion, such that the products can be transported in a disassembled state and assembled at the place of installation or at a nearby store, an assembling plant or other service facility. However, no functional modular system has ever been developed for such products. This is due to the various requirements that the cabinet must fulfil. For instance the cabinet must be constructed to be easily assembled to form a rigid and resistant cabinet having good heat insulating properties and being substantially impermeable to moisture migration as well as having an aesthetically attractive appearance. Additionally, a cooling cabinet contains a lot of technical equipment for performing different functions. This equipment, when having the present structure, is difficult to provide as modules which are easy to assemble and interconnect.
Another problem associated with conventional manufacturing of cold appliances, is that it involves high investment costs for development of product lines and the like. This results in a very poor flexibility, primarily with regard to the possibility of producing cold appliances having different dimensions and variable equipment options in small series. Normally, new product designs necessitate large production series to be feasible for economic reasons. This also has to effect that the producers are unwilling to develop products having a new approach since the economic risk is so large, with a uniformed product line as a result, alternatively that a more odd product will be very expensive to produce and purchase.
Another problem associated with a modular cold appliance is how to arrange a condensation preventing device at the front of the cold compartment(-s). In a non-module cold appliance that is conventionally manufactured, as disclosed in U.S. Pat. No. 6,666,043, a condensation preventing device is arranged as a heat carrier tube extending along a front frame portion, which surrounds the cold compartment(-s) of the cabinet. The tube is filled with a heat carrier fluid, and is provided with a heat exchanger box, which is placed under a compressor included in the cooling system of the cold appliance. In U.S. Pat. No. 6,666,043 there is no information about how the tube is actually mounted at the front frame portion, but on the other hand there is no problem involved in the mounting thereof. To the contrary, when the cold appliance is not completed in the originating factory, but delivered in pieces and assembled on arrival, a problem arises of how to manufacture the pieces in order to facilitate the assembly.
When building a cold appliance in the conventional way, where the cabinet is built on site it is easy to obtain complex built in functions. However, when providing separate parts which are going to be mounted later on, new solutions are needed. One problem to be solved is how to obtain the complex interface between the cabinet and the door, where for example the above mentioned condensation preventing device is to be mounted.
In conventional cold appliances the evaporator is formed as a rather flat and rectangular device, which is mounted inside of the cabinet. The present invention is within the field of dynamic cooling, where the cooling module is a separate module which comprises all cooling devices, including the evaporator, and is subsequently assembled with the cabinet. Then the cooled air is circulated within the cabinet in order to cool the food. The air is cooled by having it pass through or around the evaporator, depending on its construction, by means of a fan. Then the conventional rectangular and rather flat shape is not optimal.
When manufacturing separate cabinet panels which are to be subsequently mounted, instead of manufacturing a cabinet shell and fill it with foam, it should be possible, and would be desirable to find a way to automate this manufacture, at least for some of the types panels involved.
In a cold appliance where the cooling effect is generated by a cooling module according to a self-contained type, and is distributed by an air flow inside the cabinet, it is a desire to make the cooling module compact. In order to make the cooling module as compact as possible it would be desirable to arrange the largest parts, i.e. the evaporator and the compressor beside each other, though of course thermally insulated from each other. This placement may result in that at least a part of the evaporator is positioned lower than an upper portion of the compressor. This mutual positioning will have some negative impact on the defrost system, i.e. the system which effects warming of the evaporator for melting of frost and ice aggregated thereon, drainage of the resulting defrost water, and evaporation of the defrost water. Conventionally, the defrost water is evaporated from a basin on top of the compressor as the warm compressor casing is heating up the water. The water is led by gravity from the evaporator to the basin by a tube or the like. However, when the evaporator, at least partly, is positioned lower than the compressor, this is not a possible solution. Consequently, there is a need of another solution.
Furthermore, when placing the cooling module below the cabinet, which is desirable in many applications, there are air ducts for circulating air to and from the cabinet may cause warming of the cold compartment of the cabinet when defrosting the evaporator, due to warm air rising, by natural convection, through the air duct normally delivering cold air. A straight forward solution would be to restrict this heat leakage by providing air shutters in the air ducts, which will close the air ducts during the defrost periods. A drawback with such a solution is that it necessitates the arrangement of more movable parts as well as control equipment, which will increase the costs for the cooling module.
In a modular cold appliance where a system for forced air circulation in the cold compartment(s) of the cabinet is necessary there arises a need for providing an efficient circulation of the air.
SUMMARY OF THE INVENTIONAn object of the invention is to solve the above-mentioned problem associated with the condensation preventing device, and provide a cold appliance having an easily mountable condensation preventing device.
The object is achieved, in accordance with the present invention, by a cold appliance as defined in claim 1. Advantageous improvements of the method are achieved in accordance with the dependant claims of claim 1.
Thus, there is provided a cold appliance, such as a household refrigerator or freezer, comprising a cooling module, a cabinet, which cabinet has been assembled from separate cabinet panels comprising two opposite side wall panels, a rear wall panel, a top part, and a bottom part, which are connected essentially perpendicular to each other e.g. by means of joints and/or glue, a door, and a condensation preventing device including a heat carrier tube being positioned at a front frame portion of the cabinet of the cold appliance, preferably adjacent to a part of the door. The heat carrier tube is filled with a heat carrier fluid and is closed and has a boiler portion, which is arranged in thermal contact with a heat generating means of said cooling module for boiling the heat carrier fluid.
By providing the condensation preventing device as an independent unit, which is not interconnected with the cooling system of the cold appliance but has its own boiling portion that is merely arranged in thermal contact with a heat generating means of the cooling module, it is easy to assemble the cold appliance as a whole and to mount the heat carrier tube. Additionally, these features can make the mounting of the condensation preventing device more or less independent of the mounting of the cooling module. It is to be noted that the heat generating means can be, for example, a compressor, a condenser or a condenser plate of the cooling module. The invention can be carried out in many different ways within the scope of the claims. For instance, the heat carrier tube can be formed from different materials although a metal is preferred to achieve good thermal conductivity.
In accordance with an embodiment of the cold appliance, the heat carrier tube is closed in a loop. Then the heat carrier medium is able to circulate within the tube without contact with other corresponding medium of devices of the cold appliance.
In accordance with an embodiment of the cold appliance, the heat carrier tube is a one-way tube, which has two closed ends. This embodiment provides for even more simple solutions of the condensation prevention.
In accordance with an embodiment of the cold appliance, the cabinet comprises a profiled bar, which is mounted at the front frame portion e.g. at the front edge surfaces of the cabinet panels, and which is provided with support means for receiving the heat carrier tube. By providing the profiled bar, and by providing the profiled bar with the support means for receiving the heat carrier tube, the mounting of the heat carrier tube is further enhanced.
In accordance with an embodiment of the cold appliance, the heat carrier tube is snap-in connected to the support means, which underlines the easiness of mounting. However, also other ways of attachment could be conceivable, such as gluing or clamping.
In accordance with an embodiment of the cold appliance, the support means are arranged in a recess of the profiled bar, which ascertains that no excessive room is used by the heat carrier tube between the front frame portion and the door. Alternatively, the at least one side wall panel is provided with a recess for receiving the heat carrier tube.
In accordance with an embodiment of the cold appliance, when the heat carrier tube is mounted in the support means, it is covered by an elongate cover member, preferably of a metal for good thermal conductivity. Preferably the cover member is mounted with its inner surface in abutment with or at least close to the tube and the outer surface of the cover member is part of the surface of the front frame portion of the cabinet.
According to another aspect of the present invention, there is provided a condensation preventing device comprising a heat carrier tube having a boiler portion, said heat carrier tube being filled with a heat carrier fluid and being closed. The condensation preventing device is arranged to be mounted in the front frame portion of a cabinet made of pre-foamed side wall panels, a rear wall panel, a top part and a bottom part.
In accordance with embodiments of the condensation preventing device, the heat carrier tube is closed in a loop, preferably in the shape of a rectangle. The loop comprises a bottom section, a first vertical section, a top section, a second vertical section, and an end section. The top section is inclined and/or the end section is inclined. Thereby a self-circulation of the heat carrier fluid within the tube is obtainable, where the inclined section/sections enhance(s) the return circulation of liquid state heat carrier fluid.
According to another aspect of the invention, there is provided a cold appliance, wherein the cabinet further comprises a middle section adapted to divide the cabinet into more than one compartment and wherein the heat carrier tube is provided with a mid section adapted to be arranged on the front edge of the middle section.
According to another aspect of the invention, there is provided a condensation preventing device, wherein heat carrier tube is provided with a mid section and the front frame portion of a cabinet further comprises at least one middle section dividing the cabinet into more than one compartment.
In this way, a condensation preventing device can be arranged in an efficient manner also on cold appliances divided into more than one compartment. The heat carrier tube may according to this embodiment be arranged in the front frame opening of each compartment of the cabinet due to a mid section tube arranged on the heat carrier tube.
An embodiment of a modularly composed cold appliance including the invention, will hereinafter be described by way of example with reference to the accompanying drawings, in which:
In another embodiment, as shown in
In the embodiment of the cold appliance illustrated in
Preferably, the panels 1, 2, 3, 4, 103 are interconnected by means of an adhesive, or glue, which provides strong as well as tight joints. Additionally, the glued joints provide thermally good properties. Furthermore, the tightness of a glued joint ensures a high hygienic level of the cold appliance, which typically will contain foods. The reinforcing fittings 5 are mounted in the corners between the side wall panels 1 and the top panel 2 as well as the inner floor panel 103. The fittings 5 are glued to the surfaces or attached by means of appropriate fastening elements. The fittings 5 will give strength to the cabinet 101 during use as well as during curing of the glue, which preferably is used to attach the panels to each other. The fittings are also utilized as reinforcement parts for attaching e.g. door hinges or the like. It should be noted though that, as will be further explained herein, it may not be necessary to add the fittings. The cabinet may achieve a high enough stability without them as well.
According to the herein described and illustrated embodiment, the side wall panels 1 and the rear wall panels 3, 4 of the cabinet, are formed by a panel manufacturing method, as is illustrated in a schematic flowchart in
As an alternative, before the foaming operation the sheet materials are prepared for mounting of said additional attachment parts at a later stage. Thus, the sheet materials are provided with borings and the like which are to be used for mounting the attachment parts. Optionally, the sheet materials are also provided with fastening details, such as reinforcement elements, screw seats, etc., on their surfaces facing the interior of the cabinet panels to be. During the following foaming these details are embedded by the foam.
The method of manufacturing panels is advantageous in many respects. For example, the energy requirements on a cold appliance are high, and will probably increase even more in the future. By means of this method a good foam filling of the cavities is ensured. The risk of air bubbles and non-filled cavities is reduced in comparison with conventional injection moulding. Furthermore the insulating property is higher. It is possible to choose a certain orientation of the foam. All in all these advantages provide for a minimum thickness of the insulation, i.e. the foam, and thus of the panels.
As shown most schematically in
When assembling the cabinet, the cabinet panels may be connected to each other in different ways. For example; by at least one of gluing, screw fitting, and riveting. Preferably, the outer sheet layer 8 is a painted metallic sheet whereas the inner sheet layer 9 is a plastic sheet but also other variants could be conceivable, such as plastic sheets or metallic sheets on both the inner and outer surface. In
In
Thus, in
In
In
In accordance with another embodiment of the joint between cabinet panels, as shown in
All the wall panels described in relation to
A top panel is preferably attached to the side wall panel and the rear wall panel by gluing. In this way the stability of the cabinet will be enhanced and the air as well as moisture tightness will be ensured. The joints can be formed according to the embodiments disclosed in
It is sometimes desirable to form the cabinet with a separating mid wall panel, to divide the space into two different compartments having separate doors, e.g. for forming separate freezer and refrigerator compartments, or to arrange fixed shelves inside the compartments. It is also here advantageous to glue the mid wall panel or the fixed shelf to the inner surfaces of the cabinet. In the herein described and illustrated embodiment, the cooling module forms the bottom of the cabinet and preferably the cooling module is glued to the side wall and rear wall panels.
Reference is now made to
The thermosiphon tube, or heat carrier tube, 28 is part of a condensation preventing device, which is a front frame heating system arranged to avoid condensation on cold surfaces close to the door of the cold appliance or in other areas of the cold appliance where condensation may occur. In the illustrated embodiment the tube 28 is closed in an endless loop and located around the opening of the cabinet, as is illustrated in
A further embodiment of the profiled bar 140 is similar to the profiled bar 23 described above with reference to
There are many alternative shapes of the condensation preventing device, or thermosiphon tube, and some are illustrated in
According to other embodiments, as shown in
Reference is now made to
Thus, the air circulation is as follows. Cooled air flows from the evaporator 33, through the first fan 42, via the outlet air duct 43, the cold air duct 51 and the inlet air vent openings 53a into the space of the cold compartment 104. The air is distributed throughout the interior space of the cold compartment 104. Within the cold compartment 104 the interior parts, such as shelves (not shown for reasons of clarity), contributes to a substantial extent to the guidance and mixing of the air. Humidified and slightly warmed air is forced out of the cold compartment 104 through the outlet air vent openings 53b, via the warm air duct 52 and the inlet air duct 44 back to the evaporator 33. Optionally, the front inlet opening 45 is used for the humidified return air as well. However, primarily the front inlet opening 45 is used in case of a cold appliance having a refrigerator on top of and separated from a freezer, in which case the front inlet opening 45 guides air only from the freezer to the cooling module 102.
There are alternative solutions to the air circulation, including different arrangements of vent openings, differently formed lining or another solution to the air distribution within the cold compartment, different arrangement of air ducts in the cooling module, etc., as is understood by a person skilled in the art. Further, a part of the warmed up air that is ventilated from the cold compartment can be let out at the rear side of the cold appliance, in order to avoid condense at the back of the cold appliance. However, the herein described and illustrated embodiment is advantageous and presently preferred.
The rear wall lining 50 has further purposes in addition to providing opportunities for distributing cold air into as well as drawing warm air out of the cold compartment 104 through the air vent openings 53a, 53b. For instance, the rear wall lining 50 may have an aesthetic purpose. Since the rear wall panel 4 is manufactured by the manufacturing method of this invention, it can be difficult to vary the appearance of the inner surface and the rear wall lining can also be used to cover any defects which might arise especially in the inner corners of the cabinet 101 during assembling. The rear wall lining 50 can also be utilized for other kinds of installations such a lighting and control means or for hiding cabling used for such parts, and it can also be provided with supports for shelves inside the cabinet. In the illustrated embodiment shelf supports 59, which provides for a flexible positioning of the shelves, are arranged on the inner side walls of the cabinet 101.
The cooling module 102 further comprises a warm section 35, which inter alia holds a compressor 36, which is connected to an output of the evaporator 33, and a condenser tube 32, which is connected to an output of the compressor 36, as well as to an input of the evaporator, via a pressure lowering valve, as is common knowledge. The connections between the cold and the warm sections 34, 35 are made via properly sealed via-holes through the insulating wall 105. Further the warm section 35 holds a second fan 37, which is arranged at a front portion of the warm section 35, in front of the compressor 36.
The compact cooling module 102 sets tough requirements on the different solutions involved. One such solution is related to the condenser tube 32. Despite the limited space the condenser tube 32 has to be efficiently cooled. The condenser tube 32 has an extended length and is laid in windings, in one or more layers, over a metallic bottom plate 31 for enhanced cooling. The condenser tube 32 uses as large part of the area of the bottom plate 31 as possible, thereby, inter alia, partly extending beneath the cold section 34. This condenser tube—plate structure is advantageous, inter alia, in that no particular cooling flanges have to be used, and in that the overall area of the cooling structure becomes large relative to the volume occupied thereby. During operation, an air flow is drawn by means of the second fan 37 through an inlet opening 38 in the lower front portion of the cooling module 102, as is best seen in
As is apparent from the drawings, and as described above, the cooling module 102 is well insulated around the evaporator 33 and towards the cold compartment 104 in order to restrict thermal transmission between the warm section 35 of the cooling module 102 and the cold section 34 and the cold compartment 104, respectively.
In a cold appliance where the cooling effect is generated by a cooling module according to the herein described and illustrated self-contained type, and is distributed by an air flow inside the cabinet, it is a desire to make the cooling module compact. In the illustrated embodiment this results in that at least a part of the evaporator 33 is positioned lower than an upper portion of the compressor 36. This has some negative impact on the defrost system, i.e. the system which effects warming of the evaporator 33 for melting of frost and ice aggregated thereon, drainage of the resulting defrost water, and evaporation of the defrost water. Normally the defrost water is evaporated from a basin on top of the compressor as the warm compressor casing is heating up the water. The water is led by gravity from the evaporator to the basin by a tube or the like. However, when the evaporator, at least partly, is positioned lower than the compressor, this is not a possible solution. To solve this problem in the present embodiment, the condenser is structured as a condenser plate, which is also a bottom plate, 31 of metal having a length of the condenser tube, i.e. a refrigerant conduit, 32 laid in windings on the condenser plate 31 for cooling purposes, as is illustrated in
In a cooling module according to a self-contained type, as described and illustrated herein, the cooling is accomplished by dynamic cooling by which cool air is circulated in the cold appliance to cool the articles which are stored in the cold compartment. The air is cooled by passing through the evaporator 33 and the first fan 42 is used to draw the air through the evaporator 33. For the purpose of increasing the cooling capacity of the cooling module 102, the form of the evaporator 33 and the first fan 42 is adapted to each other. In the illustrated embodiment, the evaporator 33 has a substantially quadratic cross sectional shape perpendicular to the air flow, with a maximum cross-sectional dimension which is only slightly larger than the diameter of the fan. This is best seen from
A domestic cold appliance of the dynamic cooling type, as in this embodiment, is normally causing a considerable amount of frost and ice on the surface of the fins of the evaporator 33. The return airflow from the cold compartment, in particular the cold compartment of a refrigerator, is relatively warm and humid and when this air is brought to the cold evaporator the humidity is forming frost and ice on the evaporator. To avoid or at least reduce this problem, a pre-defroster plate 47 is arranged above the evaporator 33 in contact with it, as is illustrated in
In accordance with an alternative embodiment of the cooling module, as shown in
During defrosting of the evaporator 33, the heat leakage into the cold compartment 104 would normally be considerable due to air circulations in the air ducts 43, 44. With the evaporator in the very low position in the cabinet, as in this embodiment, this risk is even more evident due to natural convection of the air. One way to restrict this heat leakage is to provide air shutters in the air ducts, which will close the air ducts during the defrost periods. A drawback with such a solution is that it necessitates the provision of more movable parts as well as control equipment, which of course will increase the costs for the cooling module. Another drawback is a fall of pressure across the air shutters also when fully open. However, the cooling module according to the present embodiment will prevent, to a large extent, such heat leakage without any need for air shutters or the like. The reason for this will be explained below.
Before the defrost period the air circulation in the evaporator and cold compartment is slowed down by stopping the fan 42. When the fan is stopped the air will, after a short time, essentially stop circulating. The air movements in the cabinet will be few and small. When the defrost period start the evaporator is heated to melt ice and snow in and on the evaporator, and if there is a pre-defrost device also melt snow and ice on that one. The air inside and close to the evaporator will also be heated, and heated air expands and raises since it is lighter than colder air. This will start a movement of hot air from the evaporator to the cold compartment. If to much warm air enters the cold compartment the temperature raises and eventually this could damage the goods inside.
In order not to raise the temperature in the cold compartment to much the evaporator 33 is kept in a restricted and well insulated space with relatively small inlet and outlet openings and corresponding air ducts 43, 44. The amount of air in this restricted space is therefore quite small. During use the temperature in the evaporator is lower than the lowest temperature in the cold compartment. The movement of the air into the cold compartment is mainly passing the outlet and the air duct 43. The air duct 43 has a relatively small cross section, the air duct has a smaller cross section compared to the cross section of the evaporator, and also small openings into the cold compartment, the cross section of at least one opening into the cold compartment is smaller than the cross section of the air duct 43. Since the air has been stable for some time there have been layers of air with different temperature in the ducts, layers which are quite stable. During the beginning of the defrosting period the temperature in the evaporator and the lower part of the air duct 43 will be lower than the temperature in the cold compartment. This cold air is heavier than the air in the cold compartment and will act as a lid. When the small amount of heated air from the evaporator tries to raise in the air duct the layers will prevent air circulation upwards. This effect is also enhanced due to the small openings into the cold cabinet.
The fan could also be used to help preventing air movements up in the air ducts, since it is possible to use the fan to stabilize the airflow during defrosting. This is done by using the fan to minimize the amount of hot air leaving the cooling module or distributing hot air in a controlled way so that it is mixed with the cool air in the compartment in such a way that the temperature in the cold compartment is not raising to a level affecting the goods inside the compartment. The use of the fan could also be used in combination with shutters in the air ducts.
More particularly, according to the present invention there is provided a cold appliance comprising a cooling module, and a cabinet, which comprises a cold compartment, wherein the cooling module is arranged at the bottom of the cold appliance, wherein the cooling module comprises a cold section and a warm section, which is separated from the cold section by an insulating wall, an evaporator arranged in the cold section, and a compressor and a condenser arranged in the warm section, and wherein the cooling module comprises an air outlet for supplying cool air from the cold section to the cold compartment and an air inlet receiving air from the cold compartment to the cold section. The cold appliance is characterised in that the air outlet comprises an air duct having at least on opening into the cold compartment, said air duct extending essentially in a vertical direction and are arranged in such a way that cold air in the air duct provides a temperature layer of air which prevents entrance of heated air into the cold compartment during a period of defrosting of the evaporator.
According to a further embodiment the air in the air duct has a lower temperature than the air in the evaporator during defrosting.
According to a further embodiment, the air duct comprises at least one, preferably 3 or more, openings arranged at different heights in the cold compartment.
According to a further embodiment the air duct has a smaller cross section compared to the cross section of the evaporator.
According to a further embodiment the cross section of at least one opening into the cold compartment is smaller than the cross section of the air duct.
According to a further embodiment the cooling module comprises a fan for circulating the air through the evaporator, and cold compartment, and during defrosting of the evaporator the fan stabilises the air in the cooling module and the cold compartment such that the air circulation between the cooling module and the cold compartment is low.
The cold appliance can allow manufacturing of a cold appliance as a modular system, which is manufactured in separate modular units, to allow transporting the modular units in a cost effective, space saving way, and to allow assembling of the modular units in an uncomplicated way into a complete cold appliance near the place of use.
Thus, there is provided a cold appliance construction kit comprising a cooling module, a plurality of cabinet panels, including wall panels, to be assembled into a cabinet, and at least one door. Each cabinet panel comprises an inner sheet, an outer sheet and an intermediary layer of a foamed insulating material. Each cabinet panel has an inner surface, an outer surface, and four edge surfaces. At least one of the edge surfaces of at least a first wall panel of the wall panels is formed such that at least one of said outer and inner sheets comprises an edge portion that extends beyond the edge surface of the foamed insulating material and provides an attachment area for attachment to another cabinet panel.
Further, there is provided a cabinet for a cold appliance, which cabinet has been assembled from separate cabinet panels comprising two opposite side wall panels, a rear wall panel, a top panel, and a bottom panel, which are connected essentially perpendicular to each other by means of joints. At least the side wall panels and the rear wall panel each have an inner surface, an outer surface and four edge surfaces, and comprise an inner sheet defining the inner surface, an outer sheet defining the outer surface and an intermediary layer of a foamed insulating material. At least one of the joints between the side wall panels and the rear wall panel is designed such that at least one of the inner sheet and the outer sheet of at least a first wall panel of the wall panels involved in the joint has an edge portion that extends beyond the edge surface of foamed material and provides an attachment area at which a second wall panel involved in the joint is attached.
By means of the construction kit and cabinet, respectively, a joint which is inexpensive and easy to perform, gives stability to the cabinet, is air and moisture tight, is well insulated and presents an aesthetic pleasant appearance is obtainable.
Accordingly, by arranging an edge portion of the outer sheet of the wall panel such that is extends beyond the edge surface of the panel. In this way the extended outer sheet can optionally be bent over the edge surface, to wholly or partially cover the edge surface of the wall panel, or maintained projecting from the edge surface to utilize it as an overlapping portion. In both cases the edge portion provides the attachment area.
In accordance with embodiments of the cold appliance construction kit and the cabinet, the edge portion extends at an angle to the rest of the sheet and covers, at least partly, the edge surface of the foamed insulating material. For example, one of the wall panels involved in the joint has its outer sheet bent over the edge surface while the outer sheet of the other wall panel is projecting such that the projecting sheet is overlapping the bent over sheet.
In accordance with embodiments of the cold appliance kit and the cabinet, at least a part of an engagement area between the two wall panels at the joint is lacking any inner or outer sheet such that the wall panels are connected foam to foam in this part in order to prevent any thermal bridge between the interior of the cabinet and the ambient air.
In accordance with embodiments of the cold appliance kit and the cabinet, the outer sheet of both the first and the second wall panel at a joint, adjacent to each respective edge portion, is provided with an elongated groove formed of the outer sheet being curve shaped into the foam material, and wherein the cabinet further comprises a connection strip, which comprises two parallel longitudinal rib portions, which have been inserted into one groove each for connecting the two wall panels together.
The grooves are adapted to receive the respective elongated rib of the connection strip, preferably of plastics, which is placed over the joint between the wall panels and attached by means of for example gluing, snap fit attachment, screwing or a combination of these. The strip enhances the strength of the joint and is useful for fixing the two panels close to each other when they are being adhesively joined.
The cold appliance can relate to the above-mentioned problem associated with the condensation preventing device, and provide a cold appliance having an easily mountable condensation preventing device.
Thus, there is provided a cold appliance, such as a household refrigerator or freezer, comprising a cooling module, a cabinet, which cabinet has been assembled from separate cabinet panels comprising two opposite side wall panels, a rear wall panel, a top part, and a bottom part, which are connected essentially perpendicular to each other e.g. by means of joints and/or glue, a door, and a condensation preventing device including a heat carrier tube being positioned at a front frame portion of the cabinet of the cold appliance, preferably adjacent to a part of the door. The heat carrier tube is filled with a heat carrier fluid and is closed and has a boiler portion, which is arranged in thermal contact with a heat generating means of said cooling module for boiling the heat carrier fluid.
By providing the condensation preventing device as an independent unit, which is not interconnected with the cooling system of the cold appliance but has its own boiling portion that is merely arranged in thermal contact with a heat generating means of the cooling module, it is easy to assemble the cold appliance as a whole and to mount the heat carrier tube. Additionally, these features can make the mounting of the condensation preventing device more or less independent of the mounting of the cooling module. It is to be noted that the heat generating means can be, for example, a compressor, a condenser or a condenser plate of the cooling module. For instance, the heat carrier tube can be formed from different materials although a metal is preferred to achieve good thermal conductivity.
In accordance with an embodiment of the cold appliance, the heat carrier tube is closed in a loop. Then the heat carrier medium is able to circulate within the tube without contact with other corresponding medium of devices of the cold appliance.
In accordance with an embodiment of the cold appliance, the heat carrier tube is a one-way tube, which has two closed ends. This embodiment provides for even more simple solutions of the condensation prevention.
In accordance with an embodiment of the cold appliance, the cabinet comprises a profiled bar, which is mounted at the front frame portion e.g. at the front edge surfaces of the cabinet panels, and which is provided with support means for receiving the heat carrier tube. By providing the profiled bar, and by providing the profiled bar with the support means for receiving the heat carrier tube, the mounting of the heat carrier tube is further enhanced. In accordance with an embodiment of the cold appliance, the heat carrier tube is snap-in connected to the support means, which underlines the easiness of mounting. However, also other ways of attachment could be conceivable, such as gluing or clamping.
In accordance with an embodiment of the cold appliance, the support means are arranged in a recess of the profiled bar, which ascertains that no excessive room is used by the heat carrier tube between the front frame portion and the door. Alternatively, the at least one side wall panel is provided with a recess for receiving the heat carrier tube.
In accordance with an embodiment of the cold appliance, when the heat carrier tube is mounted in the support means, it is covered by an elongate cover member, preferably of a metal for good thermal conductivity. Preferably the cover member is mounted with its inner surface in abutment with or at least close to the tube and the outer surface of the cover member is part of the surface of the front frame portion of the cabinet.
In accordance with an embodiment of the cold appliance there is provided a condensation preventing device comprising a heat carrier tube having a boiler portion, said heat carrier tube being filled with a heat carrier fluid and being closed. The condensation preventing device is arranged to be mounted in the front frame portion of a cabinet made of pre-foamed side wall panels, a rear wall panel, a top part and a bottom part.
In accordance with embodiments of the condensation preventing device, the heat carrier tube is closed in a loop, preferably in the shape of a rectangle. The loop comprises a bottom section, a first vertical section, a top section, a second vertical section, and an end section. The top section is inclined and/or the end section is inclined. Thereby a self-circulation of the heat carrier fluid within the tube is obtainable, where the inclined section/sections enhance(s) the return circulation of liquid state heat carrier fluid.
The cold appliance can provide an interface between the cabinet and the door, which interface is capable of providing the desired functions.
Thus, there is provided a cold appliance comprising a cooling module; a cabinet comprising two opposite side wall panels, a rear wall panel, a top part, and a bottom part, and a door. Each panel comprises an inner sheet, an outer sheet and an intermediary layer of a foamed insulating material. Each cabinet panel has an inner surface, an outer surface, and four edge surfaces. The side wall panels, the rear wall panel, the top part, and the bottom part are assembled to form a cold compartment, which is closable with the door. The cold appliance further comprises a profiled bar, which is mounted at an edge surface of at least one of the panels. Preferably, the bar is mounted at the edge surfaces of a front frame portion of the cabinet.
Thus, a separate interface constituted by the profiled bar is provided. The profiled bar is manufactured separate from the cabinet panels and can be provided with different desired functions.
In accordance with an embodiment of the cold appliance, the profiled bar is made of a material, preferably a plastic material, reducing the thermal bridge between the inner surface and the outer surface of the panels during use of the cold appliance. Consequently, an appropriate choice of material improves the properties of the cold appliance, in particular when the outer and inner panel surfaces are made of metal.
In accordance with an embodiment of the cold appliance the profiled bar is attached to the edge of the panel by glue, e.g. double sided tape, which facilitates the mounting of the bar.
In accordance with an embodiment of the cold appliance the profiled bar is in abutment with the door when the door is closed, and it is provided with support means for receiving a condensation preventing device. By means of this integration of support means for the condensation preventing device in the profiled bar, the mounting thereof is simple.
In accordance with an embodiment of the cold appliance, the support means comprises a recess in which a heat carrier tube included in the condensation preventing device is received, and a cover member covering the recess. Thereby a smooth front surface is obtainable.
In accordance with an embodiment of the cold appliance, the cover member is made of a first magnetic material, and the door comprises a strip of complementary second magnetic material. Thereby the cover member and the strip in cooperation form a magnetic lock reliably keeping the door closed. In accordance with an embodiment of the cold appliance, the profiled bar provides additional functionality by having a first chamber extending along the length thereof, and a second chamber extending in parallel with the first chamber, wherein the first chamber holds the support means and is covered by the cover member, and wherein the second chamber is located closer to the interior of the cabinet than the first chamber. The second chamber can be closed and filled with an insulating material, such as air or foam.
In accordance with an embodiment of the cold appliance, the bar comprises a wing extending over an edge portion of the outer surface of a panel. This wing thus covers an outer corner, and an edge portion of the panel, which facilitates cleaning of the cold appliance and increases the appearence thereof. Additionally, it protects the insulating material.
The cold appliance can provide a cold appliance wherein the problem of the shape of the evaporator has been alleviated.
Thus, there is provided a cold appliance, such as a domestic refrigerator or freezer, comprising a cabinet having a cold compartment and a cooling module. The cooling module comprises an air outlet delivering cooled air to the cold compartment, an air inlet receiving air from the cold compartment, an evaporator, and an evaporator fan, which generates an air flow from the air inlet, through the evaporator, and to the air outlet. The cross-sectional shape of the evaporator is adapted to the airflow such that the rate of the highest air velocity to the lowest air velocity through different portions of the evaporator is minimized.
In accordance with an embodiment of the cold appliance, the cross-section of the evaporator is most preferably square, while a rectangular shape where a difference in length of the sides less than 20% works well. This is the best approximation of the shape of the cross-section swept by the evaporator fan that is available without causing excessive costs. On the other hand, according to another embodiment the cross-section of the evaporator is circular, which however adds to the costs.
In accordance with an embodiment of the cold appliance, the width of the evaporator advantageously corresponds to or is less than the cross-section swept by the evaporator fan.
In accordance with an embodiment of the cold appliance, the evaporator comprises a plurality of fin plates. The fin plates substantially increases the efficiency of the evaporator. By arranging a pre-defrost device adjacent to the evaporator, such that the air from the cold compartment is guided by the pre-defrost device before reaching the evaporator such that at least some humidity in the air from the cold compartment sticks to the pre-defrost device, several advantages are achieved. For instance, it takes longer time before the evaporator is clogged with frost/ice or the fins can be placed closer to each other without causing any shortage of the time between defrosting operations. By providing a larger number of fins, the efficiency is further raised.
It is possible to provide an automated manufacturing process for manufacturing the cabinet panels.
Thus, there is provided a method of manufacturing panels for a cold appliance, such as a household refrigerator or freezer, comprising two side wall panels, a rear wall panel, a top part and a bottom part attached together to form a cabinet, wherein each panel comprises an inner sheet, an outer sheet and an intermediary layer of foamed insulating material. The manufacturing of the panels comprises a continuous double belt foaming process and the steps of:
-
- feeding an upper and a lower sheet from respective upper and lower sheet rollers at an inlet end of a sheet forming and foam application machine;
- holding the upper and lower sheets at a distance from each other while feeding them from the inlet end towards an outlet end of the machine;
- profiling each sheet, if desired, to a profile shape,
- dispensing thermally insulating foam over the lower sheet surface in the space between the sheets;
- curing the foam, thereby obtaining a continuous sandwich web;
- cutting the sandwich web into cabinet panels, and
- controlling the cooling of the panels, such that the panel does not buckle.
By means of the method it is possible to manufacture panels as a continuous process.
In accordance with an embodiment of the method the step of profiling comprises bending an edge portion of at least one of the sheets relative to the rest of the sheet. Thereby different edge structures of the panels are obtainable for reasons of, for instance, panel assembling or reinforcement.
In accordance with an embodiment of the method further comprises at least one of:
-
- pre-machining the sheets, before the step of dispensing, to prepare them for subsequent mounting of separate parts; and
- providing the sheets, before the step of dispensing, with fastening details.
This embodiment is advantageous in that details arranged on or protruding into the inside of the sheets will be embedded in the foam subsequently applied.
According to another aspect, there is provided a method of manufacturing a cold appliance, such as a household refrigerator or freezer, comprising panels manufactured according to the method of manufacturing panels for a cold appliance, comprising the steps of assembling a cabinet, and attaching a cooling module to the cabinet, wherein the step of assembling a cabinet comprises the steps of:
-
- connecting the two side wall panels and the rear wall panel with glue along most of the length of the edge of the rear wall panel or the side wall panel; and
- connecting a top part and a bottom part to the side walls and rear wall.
The cold appliance can provide a cold appliance alleviating the above-mentioned problem which arises when the evaporator is at least partly arranged below the compressor.
Thus, there is provided cold appliance comprising a cooling module, and a cabinet, which comprises a cold compartment, wherein the cooling module comprises an air outlet delivering cooled air to the cold compartment, and an air inlet receiving air from the cold compartment. The cooling module is arranged at the bottom of the cold appliance, and it comprises a cold section, a warm section, which is separated from the cold section by an insulating wall, an evaporator arranged in the cold section, and a compressor and a condenser arranged in the warm section. The condenser comprises a condenser tube, which is arranged in windings on, or is integrated with, a bottom plate of the cooling module.
Thereby a heat generating device, i.e. the condenser tube, is available at a bottom level of the cooling module, which is usable for purposes of evaporating the defrost water.
In accordance with an embodiment of the cold appliance the cooling module comprises a drain water tray, which is arranged adjacent to the condenser tube, and which receives defrost water from the evaporator. This is an advantageous way to use the heat generated by the condenser tube for evaporating the defrost water, in combination with cooling the condenser tube efficiently.
In accordance with an embodiment of the cold appliance the drain water tray is constituted by a portion of the bottom plate. This is a simple realization of the drain water tray, where the basic structure of the cooling module is employed.
On the other hand, in accordance with an embodiment of the cold appliance, the drain water tray is constituted by a separate tray arranged on top of the condenser tube.
In accordance with an embodiment of the cold appliance the cooling module further comprises a defrost water collecting plate arranged below the evaporator, and a draining pipe extending from the defrost water collecting plate to the drain water tray, and guiding the defrost water to the drain water tray. Thereby the defrost water is safely collected and transported between the cold section to the warm section with a minimal impact on the thermal partitioning between the sections.
In accordance with an embodiment of the cold appliance the condenser tube is arranged inside the drain water tray, whereby its heat is effectively transferred to the water.
The cold appliance can provide a solution to post-mounting of parts, such as cables and air ducts, properly within the cold appliance.
Thus, there is provided a cold appliance comprising a cooling module; a cabinet comprising cabinet panels including two opposite pre-foamed side wall panels, a pre-foamed rear wall panel, a top part, and a bottom part; and a door. The cooling module comprises an air outlet delivering cooled air to the cold compartment, and an air inlet receiving air from the cold compartment. The cold appliance further comprises a rear wall lining, which is arranged at the inside of the pre-foamed rear wall panel, and which forms a space between the rear wall lining and the rear wall panel.
The lining is realisable as a separate part that is easy to mount, and many post-mounted parts can be hidden in the space between the rear wall lining and the rear wall panel.
In accordance with an embodiment of the cold appliance, the rear wall lining comprises an inlet air duct connected with said air outlet, and an outlet air duct connected with said air inlet, which ducts are arranged in said space, first air vent openings connected with said inlet air duct and with the cold compartment, and second vent openings connected with said outlet air duct and with the cold compartment. Thereby the rear wall lining is useful for arranging the air circulation within the cold compartment in a desired way.
In accordance with an embodiment of the cold appliance the rear wall lining is used for hiding cables running in the space. Thus, an additional functionality of the lining is provided. That is the case for another embodiment as well, where the cold appliance further comprises electric elements mounted at the rear wall lining. Such elements are for instance a fan, lighting, a temperature sensor, and a motor.
In accordance with an embodiment of the cold appliance, it further comprises shelf supports arranged on the rear wall lining.
In accordance with an embodiment of the cold appliance, the rear wall lining is attached to the rear wall by mechanical means, e.g. press fitting or snap fitting. This solution provides a fast and simple attachment.
The cold appliance can provide a device for increasing the thermal as well as the cost efficiency of an evaporator and to avoid or at least reduce the forming of frost and ice on the evaporator.
Thus, there is provided a cold appliance, such as a refrigerator or a freezer, comprising a cabinet having a cold compartment and a cooling module, wherein the cooling module comprises an air outlet delivering cooled air to the cold compartment, an air inlet receiving air from the cold compartment, an evaporator, and an evaporator fan, which generates an air flow from the air inlet, through the evaporator, and out of the air outlet. The cooling module further comprises a pre-defrost device, which is arranged adjacent to the evaporator, such that the air from the cold compartment is guided by the pre-defrost device before reaching the evaporator, such that at least some humidity in the air sticks to the pre-defroster device.
Accordingly, by arranging a pre-defrost device, which is in contact with or close to the evaporator and/or the cold airflow from the evaporator, letting the return airflow from the cold compartment pass the pre-defrost device, at least a part of the humidity contained in the airflow will condensate and freeze on the pre-defrost device before it reaches the evaporator.
In accordance with an embodiment of the cold appliance, the pre-defroster device is arranged in thermal contact with the evaporator such that when the evaporator is heated for defrosting the pre-defrost device also is defrosted. Consequently, no separate defrosting of the pre-defrost device is necessary.
In accordance with an embodiment of the cold appliance, the pre-defrost device includes a plate, and is positioned on top of the evaporator. Thereby it forms a lower wall defining an air duct for the return airflow. However, the pre-defroster member could also have many other shapes, e.g. as a circular or square tube surrounding the evaporator and/or the cold airflow from the evaporator, such that the warm and humid return airflow is brought to flow on the outside around the tube before entering the evaporator.
In accordance with an embodiment of the cold appliance air is admitted to pass through the pre-defrost device, e.g. by arranging it with spaced flanges, or by making it of a porous material.
In accordance with an embodiment of the cold appliance the pre-defrost device comprises a first end and a second end, the air from the cold compartment passes the first end before the second end, and the first end is located at a distance from the main inlet to the evaporator. This means that air is admitted to freely contact an upper portion of the evaporator, or passing through a portion of the evaporator from above in addition to entering the evaporator from the main inlet end.
In accordance with an embodiment of the cold appliance the distance between fin plates in the evaporator is between 2-10 mm, and preferably between 3-5 mm. These distances are rather small compared to what would be appropriate if the pre-defrost device would not have been provided.
The cold appliance can provide a cabinet design that has a good stability and strength although it has been assembled from separate parts.
Thus, there is provided a cold appliance, such as a household refrigerator or freezer, comprising a cabinet and a cooling module, which cabinet comprises cabinet panels including two opposite side wall panels, a rear wall panel, and a top part, which are connected essentially perpendicular to each other by means of mechanical and/or glue joints. Each cabinet panel comprises an inner sheet, an outer sheet and an intermediary layer of a foamed insulating material, wherein each cabinet panel has an inner surface, an outer surface, and four edge surfaces. The cooling module comprises a cold section and a warm section, which is separated from the cold section by an insulating wall, an evaporator arranged in the cold section, and a compressor and a condenser arranged in the warm section. The cooling module comprises a bottom part comprising support means, such as wheels and/or feet, and the bottom edge surface of at least one of the side wall panels is attached to the bottom part.
In accordance with an embodiment of the cold appliance, each one of the side wall panels are glued together with the rear wall panel over a major part of the vertical edge surface of the side wall panel or the rear wall panel. The glue joints thus having a significant area, distribute the tensions generated in the cabinet by the thermal loads occurring during use of the cold appliance.
In accordance with embodiments of the cold appliance, each joint between one of the side wall panels and the rear wall panel comprises a vertical elongated groove formed at one of the side wall panel and the rear wall panel, and a connection strip arranged at the other and inserted into the groove such that the vertical edge surface of the side wall panel or the rear wall panel is pressed against the inner surface of the rear wall panel or the inner surface of the side wall panel. The groove—strip connection further strengthens the joints.
In accordance with an embodiment of the cold appliance, a reinforcing fitting is attached in the front corner between the side wall panel and the top part for e.g. attachment of a door hinge.
In accordance with an embodiment of the cold appliance, at least one of the pre-foamed side wall panels is manufactured by means of a method which comprises a continuous double belt foaming process, preferably also the rear wall panel.
In the drawings and specification, there have been disclosed preferred embodiments and examples of the invention. Features and details described in the different embodiments and examples are not limited to be used in that specific embodiment or example unless explicitly so stated. If not stated otherwise, features in one embodiment or example can therefore be used in another embodiment or example. It will also be evident to the person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.
Claims
1. A cold appliance, such as a household refrigerator or freezer, comprising a cooling module (102), a cabinet (101), which cabinet has been assembled from pre-foamed panels comprising two opposite side wall panels (1), a rear wall panel (4), a top part (2), and a bottom part (103), which are connected essentially perpendicular to each other e.g. by means of mechanical and/or glue joints, and a door (6), characterized in that the cabinet comprises a condensation preventing device (160) comprising a heat carrier tube (28, 160) being positioned at a front frame portion of the cabinet of the cold appliance, preferably adjacent to a part of the door (6), the heat carrier tube being filled with a heat carrier fluid, being closed and having a boiler portion (172), which is arranged in thermal contact with a heat generating means (32) of said cooling module for boiling the heat carrier fluid.
2. A cold appliance according to claim 1, wherein the heat carrier tube (28, 160) is closed in a loop.
3. A cold appliance according to claim 1, wherein the heat carrier tube (180, 190) is a one-way tube having two ends, which each is closed.
4. A cold appliance according to claim 1, wherein the cooling module (102) comprises a condenser, preferably the condenser comprises a condenser tube (32) arranged in windings on a bottom plate (31) of the cooling module, arranged in thermal contact with the boiler portion (172) of the heat carrier tube.
5. A cold appliance according to claim 1, wherein the cabinet (101) comprises a profiled bar (23), arranged at the front frame portion, e.g. at the front edge surfaces (16) of the cabinet panels (1), and which comprises a support means (27) for receiving the heat carrier tube (28).
6. A cold appliance according to claim 5, wherein the heat carrier tube (28) is snap-in connected to the support means (27).
7. A cold appliance according to claim 5, wherein the support means are arranged in a recess (25) of the profiled bar (23), which recess is closable by means of an elongate cover member (26).
8. A cold appliance according to claim 7, wherein the heat carrier tube (28) is in abutment with the cover member (26).
9. A cold appliance according to claim 1, wherein the at least one side wall panel (1) is provided with a recess (25) for receiving the heat carrier tube.
10. A cold appliance according to claim 1 wherein the cabinet (101) further comprises a middle section (7) adapted to divide the cabinet into more than one compartment and wherein the heat carrier tube (160) is provided with a mid section (165, 180′, 190′) adapted to be arranged on the front edge of the middle section.
11. Condensation preventing device comprising a heat carrier tube (160) having a boiler portion (172), said heat carrier tube being filled with a heat carrier fluid and being closed, wherein the condensation preventing device is arranged to be mounted in a front frame portion of a cabinet (101) made of pre-foamed side wall panels (1), a rear wall panel (4), a top part (2) and a bottom part (103).
12. Condensation preventing device according to claim 11, wherein the heat carrier tube (160) is closed in a loop, preferably in the shape of a rectangle.
13. Condensation preventing device according to claim 12, wherein the loop comprises a bottom section (162), a first vertical section (164), a top section (166), a second vertical section (168), and an end section (170).
14. Condensation preventing device according to claim 13, wherein the top section (166) is inclined and/or the end section (170) is inclined.
15. Condensation preventing device according to claim 11, wherein the heat carrier tube comprises at least one one-way tube (180) having two ends, which each is closed, and preferably two one-way tubes (180, 190) having two ends, which each is closed.
16. Condensation preventing device according to claim 11, wherein the cross-section of the boiler portion (176) is larger than the cross-section of the major part of the rest of the tube (160).
17. Condensation preventing device according to claim 1, wherein heat carrier tube is provided with a mid section (165, 180′, 190′) and the front frame portion of a cabinet (101) further comprises at least one middle section (7) dividing the cabinet into more than one compartment.
Type: Application
Filed: May 19, 2009
Publication Date: Jul 28, 2011
Applicant: AKTIEBOLAGET ELECTROLUX (Stockholm)
Inventors: Bernt Andersson (Stockholm), Klas Andersson (Lidingo)
Application Number: 12/992,161
International Classification: F25D 21/04 (20060101); F25D 23/02 (20060101);