A DEVICE FOR DIRECTING CONVECTIVE AIR CURRENTS IN REFRIGERATORS

Abstract: A device for directing convective air currents in refrigerators of the type comprising a refrigerating compartment (40) and a freezing compartment lodging an evaporator (30) with a lateral profile in the form of a "C" turned to the front of said compartment. According to the invention, there is mounted, to the front edge of the upper wall (31) of the evaporator (30), a plurality of fins (60) arranged in vertical planes, which are parallel and spaced from each other and orthogonal to the rear wall (12) of the freezing compartment (10).

Description: A DEVICE FOR DIRECTING CO VECTIVE AIR CURRENTS IN REFRIGERATORS Field of the Invention The present invention refers to a device for directing the flow of air currents of natural convection inside the cabinet of refrigerators comprising a freezing compartment, provided with a plate type evaporator with a lateral profile in the form of a "C" turned to the front of said compartment, and with a refrigerating compartment having an evaporating plate provided close to the rear wall of the refrigerating compartment, each of said compartments being closed by a respective front door usually provided with inner shelves . Background of the Invention There are known from the art the refrigerators using natural convection and with a cabinet provided with a usually superior freezing compartment and with a usually inferior refrigerating compartment, these compartments being separated from each other by a thermically insulated horizontal dividing wall. The refrigerating compartment is designed for storing fresh products, while the freezing compartment reaches negative temperatures, in order to keep the food stored therein in a frozen condition. Due to the below zero temperature conditions existing inside the freezing compartment, there occurs the undesirable side effect of ice formation on the evaporator surface, mainly from the humidity of the air which circulates, by natural convection, inside the freezing compartment, the ice formation in this evaporator also resulting, although in a smaller degree, from the humidity of the air which penetrates in the freezing compartment upon opening of the respective front door. In this evaporator of the plate type with a lateral profile in the form of a "C" turned to the front door, the ice tends to form more markedly in the center of the front edge of the upper wall of the evaporator, concentrating in this region and rapidly becoming visible to the user when he opens the front door of said compartment. This non-homogenous formation of ice in the evaporator of the freezing compartment, besides giving to the product a negative aspect, which is associated with an operational inefficiency, usually leads to a premature obstruction of the door, impairing or making inefficient the closing of the freezing compartment. The problem cited above results from the formation of convective currents inside the freezing compartment, flowing from the lateral walls thereof towards the upper central region of the evaporator. Disclosure of the Invention It is a general object of the present invention to provide a device for directing convective air currents in refrigerators having a freezing compartment and a refrigerating compartment, in order to guarantee a homogeneous formation of ice in the front upper edge of the evaporator of the freezing compartment. The device for directing convective air currents of the present invention is applied to refrigerators of the type considered herein and comprises a plurality of fins arranged in vertical planes, which are parallel and spaced from each other and orthogonal to the rear wall of the freezing compartment, said fins being mounted to the front edge of the upper wall of the evaporator, in order to be projected rearwardly, but more markedly forwardly from said front edge, and downwardly, but more markedly upwardly from the upper wall of the evaporator. With the above described constructive arrangement, it is avoided, inside the freezing compartment, the formation of convective currents flowing from the sides to the center of the upper wall of the evaporator, these currents then being rearwardly directed, over the upper wall of the evaporator, towards the rear wall of the freezing compartment, when said currents form a descending cold air current, flowing along the rear wall of the evaporator, until reaching the lower windows of said rear wall, said windows allowing the descending cold air current to pass to the inside of the "C" profile of the evaporator, starting a new cycle of relative heating and formation of hot air currents to be directed by the fins . Brief Description of the Drawings The invention will be described below, with reference to the attached drawings, in which: Figure 1 is a partially cut front perspective view of a refrigerator of the type considered herein and provided with the device for directing convective air currents of the present invention; and Figure 2 is a vertical sectional view of the freezing compartment illustrated in figure 1. Description of the Illustrated Embodiment As illustrated in the appended figures, the device for directing convective air currents of the present invention is applied to a refrigerator of the type comprising a freezing compartment 10, which is usually superior and parallelepipedic, with an upper wall 11, a rear wall 12, lateral walls 13 and a bottom wall 14, and which is closed at the front with a front door 20 provided with inner shelves 21. The freezing compartment 10 is internally refrigerated by an evaporator 30, usually of the plate type with a lateral profile in the form of a "C" turned to the front door 20 and having an upper wall 31 and a rear wall 32 spaced from the upper wall 11 and rear wall 12, respectively, of the freezing compartment 10, and also a lower wall 33 usually seated against the bottom wall 14 of the freezing compartment 10. The rear wall 32 of the evaporator 30 is inferiorly provided with windows 34, in order to allow the descending cold air current, which is formed between the rear wall 12 of the freezing compartment 10 and the rear wall 32 of the evaporator 30, to pass into the latter and freeze the products stored in said freezing compartment. The refrigerator further comprises a refrigerating compartment 40, which is generally provided under the freezing compartment 10 and separated therefrom by its own thermically insulated bottom wall 14, and which is closed by a front door 50 and refrigerated by a rear evaporating plate (not illustrated) . According to the invention, the device for directing convective air currents comprises a plurality of fins 60 arranged in vertical planes, which are parallel and spaced from each other and orthogonal to the rear wall 12 of the freezing compartment 10, these fins 60 being mounted to the front edge of the upper wall 31 of the evaporator 30 and constructed in any adequate material, such as plastic. The fins 60 are arranged and dimensioned to be projected rearwardly, but more markedly forwardly from the front edge of the upper wall 31 of the evaporator 30 and also downwardly, but more markedly upwardly from the upper wall 31 of the evaporator 30, whereby these fins 60 usually occupy substantially the whole height of the gap defined by the spacing between the upper wall 31 of the evaporator 30 and the upper wall 11 of the freezing compartment 10. The projection of the fins 60 forwardly from the front edge of the upper wall 31 of the evaporator 30 is dimensioned so that the fins occupy substantially the entire spacing existing between the evaporator 30 and the front door 20. The dimensioning of the fins 60, in the form as mentioned above, allows said fins to "rectify" the flow by natural convection which is established inside the freezing compartment, deviating the usual transversal currents of humid air and directing them towards the rear wall 12 of the freezing compartment 10, over the upper wall 31 of the evaporator 30, preventing the humid air from flowing to the center of the front edge of the upper wall 31 of the evaporator 30, provoking ice accumulation thereon. As illustrated in the drawings, the fins 60 have a preferably funnel-shaped front portion, in order to adjust to the inner profile of the freezing compartment 10, projecting forwardly from the front edge of the upper wall 31 of the evaporator 30, said projecting front portion having an extension of about 50-70 mm, which may vary in function of the project characteristics of the freezing compartment 10. The projection of the fins 60 rearwardly from the front edge of the upper wall 31 of the evaporator 30 is usually of 30 mm, but it can vary in function of the refrigerator project. According to the illustrated embodiment, the fins 60 are affixed to a transversal rod 70, which is designed in order to be easily and securely mounted to the front edge of the upper wall 31 of the evaporator 30. However, it should be understood that this constructive solution is only illustrative, since the fins 60 may be affixed to the evaporator 30 in different ways.

Claims: CLAIMS 1. A device for directing convective air currents in refrigerators, comprising a refrigerating compartment (40) and a freezing compartment (10) provided with an upper wall (11), a rear wall (12), lateral walls (13) and a bottom wall (14) and lodging an evaporator (30) with a lateral profile in the form of a "C" turned to a front door (20), and with an upper wall (31) and a rear wall (32), which are spaced from the upper wall (11) and rear wall (12) of the freezing compartment (10), characterized in that it comprises a plurality of fins (60) arranged in vertical planes, which are parallel and spaced from each other and orthogonal to the rear wall (12) of the freezing compartment (10), said fins being mounted to the front edge of the upper wall (31) of the evaporator (30), in order to be projected rearwardly, but more markedly forwardly from said front edge, and downwardly, but more markedly upwardly from the upper wall (31) of the evaporator (30) . 2. Device, as in claim 1, characterized in that the fins (60) project upwardly from the upper wall (31) of the evaporator (30), by a height which is substantially equal to the spacing between said upper wall (31) of the evaporator (30) and the upper wall (11) of the freezing compartment (10). 3. Device, as in claim 1, characterized in that the fins (60) project forwardly from the front edge of the upper wall (31) of the evaporator (30) by a distance which is sligthly smaller than the spacing between said front edge and the front door (20) of the freezing compartment (10). 4. Device, as in claim 1, characterized in that the fins (60) have a funnel shaped front portion, projecting forwardly from the front edge of the upper wall (31) of the evaporator (30). 5. Device, as in claim 1, characterized in that the fins (60) are affixed to a transversal rod (70) mounted to the front edge of the upper wall (31) of the evaporator (30) .

Inventors: LOPES LUIZ ANTONIO DIEMER, LOPES, LUIZ, ANTONIO, DIEMER
Applicants: MULTIBRAS ELETRODOMESTICOS SA, MULTIBRAS S.A. ELETRODOMESTICOS
Application year: 2000
Main classification: F25D17
IPC codes: F25D11, F25D17