EP1267137A1

EP1267137A1 - Upright freezer and refrigerator comprising same

Info

Publication number: EP1267137A1
Application number: EP02010284A
Authority: EP
Inventors: Enrica Monticelli; Giuseppe Panighini; Mauro Piloni
Original assignee: Whirlpool Corp
Current assignee: Whirlpool Corp
Priority date: 2001-06-12
Filing date: 2002-05-21
Publication date: 2002-12-18
Anticipated expiration: 2022-05-21
Also published as: ES2312506T3; EP1267137B1; ITVA20010006U1; BR0202179A; DE60229026D1; BR0202179B1

Abstract

A domestic upright freezer comprises a cavity in which, at various levels, there are arranged flat portions (10a, 10b, 10c) of the cooling coil, said portions commonly being known as "grids". One of said portions, and preferably the upper portion, comprises a metal plate (12), on the lower face of which is accommodated the associated evaporator portion.

Description

The present invention relates to a domestic freezer of the type comprising a cavity in which, at different levels, there are arranged flat members for the products to be frozen, said members essentially being constituted by evaporator coil portions interconnected in series. A domestic freezer is taken to mean here either an upright freezer or a refrigerator comprising same, for example refrigerators with two or more compartments in which at least one compartment is at a temperature substantially below 0°C, either of the superimposed type ("fridge/freezer" refrigerators) or of the side-by-side type.
In known freezers, the shelves for the deep-frozen and/or frozen products which are kept at low temperatures for extended periods are constituted by the above-stated "grids", i.e. horizontal evaporator portions defined by a looped course of the evaporator tubing to which there are attached (for example by welding or brazing) a plurality of metal rods or wires. These latter cooperate with the evaporator tube to increase the heat-exchange surface thereof, to stiffen the structure thereof and, in some cases, act as a support for the foodstuffs when the latter are not contained in suitable sliding boxes or baskets arranged between the grids. Such an embodiment offers the advantage of ensuring good air circulation (and thus good heat exchange) between the grids, but suffers from non-uniform temperatures within the chamber primarily due to the arrangement of the upper grid, which is located close to the top of the chamber.
The object of the present invention is to provide a freezer of the type defined above at the beginning of the description, which freezer offers advantages both in terms of energy saving and in terms of reducing product costs.
Said object and other advantages are achieved by a freezer as defined in the attached claims.
Using a metal plate which accommodates the tubing of the highest portion of the evaporator (i.e. that which is closest to the top of the freezer cavity) makes it possible to achieve more efficient cooling of the upper part of the freezer compartment, which is typically hotter than the other zones. Thanks to said more efficient cooling, the temperature gradient within the cavity is reduced and thus so too is the energy wastage associated with an uneven temperature distribution within the compartment. Another advantage of the freezer according to the invention is the elimination of the separate holding tank (or "canister") which is conventionally fitted beside the grid stack for the purpose of collecting the refrigerant fluid in the liquid phase prior to input into the compressor, so as to avoiding damaging the compressor valves. This is possible by incorporating said tank into the metal plate acting as the upper grid. Providing the plate instead of a conventional "grid" allows the user to make better use of the small space defined by the upper grid and of the top of the cavity (currently used to contain eutectic packs). Since, according to the invention, the metal bars or wires of the grid are eliminated, so too are cleaning problems and the user is able to make better use of this space, albeit small.
Further advantages and features of a freezer according to the invention will be obvious from the following detailed description, which is provided merely by way of non-limiting example, with reference to the attached drawings, in which:

Figure 1 is a perspective view of a grid stack used in a freezer of conventional design;
Figure 2 is a view similar to Figure 1 and shows a grid stack of a freezer according to the invention;
Figure 3 is a plan view from beneath (with reference to its in-service configuration) of a plate used in the freezer of Figure 2 in its state prior to folding into an L-shape of a rear portion thereof along a line indicated P;
Figure 4 is a plan view (according to the arrow IV) of the metal plate shown in the grid stack of Figure 2; and
Figure 5 is a view according to arrow V of the metal plate shown in the grid stack of Figure 2.

In the solution according to the invention, shown in Figures 2-5, the evaporator comprises an upper metal plate 12 exhibiting a horizontal portion 12a (in the in-service configuration of the evaporator inside a freezer chamber) and a portion folded into an L shape 12b which, in the installed configuration of the evaporator 10, is suitable to fit close to a rear vertical wall of the freezer chamber. Both the portions 12a and 12b of the metal plate 12 provide tubing K accommodated in association with the faces respectively facing downwards and towards the vertical wall of the chamber (not shown). In particular, the tubing K may be obtained for example by means of one of the techniques used in the production of roll-bond or Z-bond type evaporators, in which two superposed metal sheets are deformed under pressure in predetermined zones to form the coil or tubing for passage of the refrigerant fluid.
With particular reference to Figure 3, 14 is the inlet connection of the capillary tube C into the vertical portion 12b of the plate 12. The refrigerant fluid expands in the tubing K provided in association with the horizontal portion 12a of the plate 12 in the direction shown by the arrows. On leaving the horizontal portion 12a of the plate 12 at the outlet A, the refrigerant fluid continues to expand in portions 10b and 10c beneath, which are entirely similar to those used in the conventional solution described in Figure 1. On leaving the lower portion 10c of the evaporator, the return tube is connected at B to the vertical portion 12b of the plate 12, in which is accommodated an elongate holding tank 16 obtained by the same technique used to obtain the tubing K. The tank 16 does not communicate with the connection 14 and with the portion of the evaporator downstream from the connection, but is connected at 18 to a return tube 20 to the compressor. A portion of the capillary tube is wound around the tube 20 before the input connection 14, for the purpose of improving heat exchange between the gaseous refrigerant fluid leaving the tank 16 and the refrigerant fluid being input into the plate 12 of the evaporator 10.
It is obvious how the flat, smooth surface of the upper side of the portion 12a of the plate 12 readily lends itself to easy cleaning within the space constraints allowed by the small distance between the plate 12 and the ceiling of the freezer chamber. Moreover, inserting or removing small items, for example ice-cube trays, is much easier in comparison with conventional metal wire grids.
Although the description refers to an upper plate in which the tubing is obtained by means of plastic deformation of one of two facing metal sheets integral one with the other, the results of the present invention are also understood to extend to solutions in which the coil is welded onto a(n under)side of a metal sheet or to the solution in which the plate is formed from two facing sheets with opposing half-channels forming the coil.

Claims

A domestic freezer of the type comprising a cavity in which, at various levels, there are arranged flat members (10a, 10b, 10c) defined by portions of coil evaporator in the form of grids, characterised in that at least one of said supports (10a) comprises a metal plate (12), on one of the faces of which there is accommodated or arranged the associated evaporator portion.
A freezer according to claim 1, characterised in that the evaporator portion is substantially accommodated in association with a lower face of the plate (12).
A freezer according to claim 1 or 2, characterised in that said plate (12) is arranged close to an upper wall of the freezer cavity.
A freezer according to claim 1 or 3, characterised in that a holding tank (16) to collect the refrigerant fluid upstream from the compressor is integral with the plate (12).
A freezer according to claim 4, characterised in that the plate comprises a vertical portion (12b) folded into an L shape and is arranged close to a vertical wall at the back of the cavity, said holding tank (16) being accommodated in association with said vertical portion (12b).
A freezer according to claim 5, characterised in that the connection between the capillary of the refrigerant circuit and the evaporator is provided in association with said vertical portion (12b) of the plate (12).
A freezer according to claim 5 or 6, characterised in that the connection of the return tube (B) of the lower portion (10c) of the evaporator (10) is provided in association with said holding tank (16).
A freezer according to any one of the preceding claims, characterised in that the evaporator portion of the metal plate (12) is manufactured by means of plastic deformation of a coil-shaped zone of said plate.