The present invention refers to a condenser of the tube-plate type to be used in the refrigeration system of appliances, such as refrigerators and freezers presenting an internally refrigerated cabinet with external walls that are at least partially defined in a metallic plate.
There are well known in the prior art the refrigeration appliances presenting a cabinet with external walls made of a metallic plate and a refrigeration system comprising a condenser of the tube-plate type that uses at least one of said external walls of the cabinet as a heat dissipating fin, against which is internally seated the tubing for conducting the refrigerant gas pumped by the compressor and which will be condensed before entering an evaporator of the refrigeration system.
As it can be noted from
However, this known condenser construction of the tube-plate type presents some disadvantages, one of which resulting from the fact that the cylindrical tube 10 is seated against the flat surface of the external wall 20, whereby only one tangential contact line is formed between the tube 10 and the external wall 20, requiring the provision of the tape 30 in order to assure not only the fixation of the tube 10, but a greater thermal contact between these two condenser parts, namely the tube 10 and the respective external wall 20.
Another great disadvantage of the known construction results from the high cost of the adhesive aluminum tape 30.
Yet a further disadvantage of said tube-plate condenser construction results from the slow assembly process thereof.
Due to the above mentioned deficiencies related to the constructive system of the condensers of the tube-plate type, it is an object of the present invention to provide a condenser of the type considered herein, with a construction that is simple and rapid to produce, requiring reduced manual operations and eliminating the usual tapes for affixing the tube to the respective external wall of the cabinet.
It is a further object of the present invention to provide a condenser as mentioned above, which allows an efficient thermal exchange between the compressed refrigerant gas and the external environment of the cabinet, without requiring the provision of elements projecting outwardly from the contour of the external walls of the cabinet.
In order to attain the objectives mentioned above, the present invention proposes a condenser comprising at least one condensation coil formed by a plurality of tube extensions for conducting the refrigerant gas, which are seated and retained in respective grooves formed by bending the metallic plate of a respective external wall of the cabinet.
Each groove is configured and dimensioned to tightly “embrace” preferably more than half the perimeter of the outer face of the respective tube extension, so as to maximize the contact area between the tube extensions and the metallic plate that defines the respective external wall of the cabinet.
The retention of the tube extensions is now made by interference, dispensing the fixation tapes.
The invention will be described now, with reference to the enclosed drawings, in which:
As already mentioned, the present condenser of the tube-plate type is applied to the refrigeration system of different refrigeration appliances, such as refrigerators and freezers presenting a cabinet G to be internally refrigerated and which has external walls 20, generally in a metallic plate, and internal walls 40 usually defined in a single piece of plastic material and denominated inner box. Between the internal walls 40 and the external walls 20 a filler 50 of polyurethane foam is inserted to provide the required thermal insulation to the cabinet G.
In order to eliminate the disadvantages of the prior art construction already discussed at the introduction of the present application jointly with
In the illustrated embodiment, the grooves 21 are opened to the outside of the respective external wall 20 of the cabinet G. The external wall 20 used can be the one that defines the rear closing part of the cabinet G, considering that this external wall 20 is generally made of a steel plate as a separate piece from the single metal sheet that defines the lateral and upper external walls of a parallelepipedic cabinet G. It should be understood that the grooves 21 can open to the interior of the respective external wall 20, which would present ribs on the outer face thereof, resulting from the bottom of the grooves 21 projecting outwardly from the plane of said external wall 20.
Aiming at maximizing the contact area between each tube extension 10 and the respective groove 21, the latter presents a cross section that is configured and dimensioned to tightly “embrace” the tube extension 10, by preferably contacting more than half the external perimeter of the latter.
In order to form the condenser, the tube extensions 10 of the condensation coil S are lodged inside the respective grooves 21 of an external wall 20, whose metallic plate is previously stamped. Subsequently, the metallic plate is submitted to a localized pressing, in order to partially close the grooves 21 around the tube extensions 10, embracing the latter and assuring a larger contact area and the retention of the tube extensions 10 inside the grooves 21, since the opening 21a of the latter now presents a width that is smaller than the largest transversal dimension of the tube extension 10, taken according to a direction parallel to the respective external wall 20. However, it should be understood that the tube extensions 10 can be seated inside the grooves 21 and affixed therein by an additional common fixation element, which is coupled to the external wall and acts against the exposed surface portion of the tube extensions 10.
The tube extensions 10 generally present a circular cross section, making the grooves 21 present the same cross section shape, in order to operate as a cradle, in which the respective tube extensions 10 will be tightly seated.
In the illustrated embodiment, the grooves 21 present a depth that is substantially equal to the largest transversal dimension of the tube extension 10, taken at a direction that is orthogonal to the respective external wall 20. Thus, the external surface of the tube extension 10 is generally arranged in a tangential way in relation to the plane of the external wall 20, allowing the formation of a condenser that is entirely contained in the external contour of the cabinet and with the constructive and assembly advantages mentioned above.
The increase in the thermal efficiency of the construction proposed herein allows this condenser of tube-plate type to have its positioning changed from the lateral external walls of the cabinet G of a refrigerator or a freezer to be associated to the rear external wall 20 of said cabinet G, avoiding the problem of leaving marks on the lateral external walls upon injection of polyurethane in the conventional, constructions, in which the tube extensions are internally affixed to said lateral external walls.
Depending on the characteristics of the refrigeration system, the provision of one or more additional condensation coils S1, S2 may be required, arranged in series with the condensation coil S and associated with the top and bottom external walls 20 of the cabinet G. In this case, the tube extensions 10 can be seated and affixed against the flat inner face of the external walls 20 that define the top and bottom of the cabinet G, according to the prior art construction, as illustrated in
Although only one form of carrying out the invention has been described, it should be understood that the invention can have different embodiments, resulting in the same advantageous effects over the solutions known up to now. Thus, the protective scope of the invention should not be limited to the described illustrated form, but solely to the constructive concept contained in the appended claims.
Number | Date | Country | Kind |
---|---|---|---|
PI 0107297-8 | Nov 2001 | BR | national |
PI 0203671-1 | Aug 2002 | BR | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/BR02/00147 | 11/5/2002 | WO |