Refrigerator Having a Disbursed Cooling Air Stream Directed Upwardly From a Pressurized Plenum

Abstract

In a refrigerator, warm air is collected or drawn into a warm air return duct opening located at or near the top of the refrigerated space instead of the bottom. The warm air is passed through an evaporator where it cools. The cooled air is driven into a pressurized plenum located at the bottom of the refrigerated space. The plenum is defined by a screen extending across the bottom of the refrigerated space. Air in the plenum passes through holes in the screen and driven upward. The air flow inside the refrigerator is thus upwardly, i.e., from the bottom to the top.

What is claimed is: 
     
         1 . A refrigerator having an interior defined by first and second sides, a rear side, a front opening having a door, a top and a bottom, the refrigerator comprising:
 a first inclined screen portion located proximate to the bottom and between the first and second sides of the interior and between the rear side of the interior and the front opening, the first inclined screen portion having a front edge proximate the front opening and a rear edge proximate the rear side, the inclined screen portion having a first inclination angle, relative to horizontal defining a converging first duct portion, the first duct portion having a first height at the rear edge and a smaller second height at the front edge, the first duct portion having an opening at the rear edge;   wherein the inclination angle and openings in the screen establish an air flow profile in the refrigerator cabinet.   
     
     
         2 . The refrigerator of  claim 1 , wherein the first inclined screen portion extends to first and second sides and extends to the rear side. 
     
     
         3 . The refrigerator of  claim 1 , wherein the screen is comprised of:
 a panel having a top surface and a bottom surface, a first thickness between the top and bottom surfaces, and a number of first openings, the number of openings having a first area and extending through the top and bottom surfaces;   wherein, the number of first openings, the first thickness, the first area, and the first inclination angle being selected and configured to provide a distribution of air flow through the first inclined screen portion responsive to an input air stream at the duct opening.   
     
     
         4 . The refrigerator of  claim 3 , wherein the first openings are substantially uniformly spaced apart from each other. 
     
     
         5 . The refrigerator of  claim 3 , wherein the first openings are substantially uniformly sized. 
     
     
         6 . The refrigerator of  claim 3 , wherein the first openings are non-uniformly spaced apart from each other. 
     
     
         7 . The refrigerator of  claim 3 , wherein the first openings are non-uniformly sized. 
     
     
         8 . The refrigerator of  claim 1 , wherein the first thickness, first area and number of first openings and the first inclination angle are configured to provide a distribution of air flow through the first inclined screen portion that is substantially uniform across the area of the first inclined screen portion. 
     
     
         9 . The refrigerator of  claim 1 , wherein the first thickness, first area and number of first openings and the first inclination angle are configured to provide a non-uniform distribution of air flow through the first inclined screen portion. 
     
     
         10 . The refrigerator of  claim 1 , wherein the first thickness, first area and number of first openings and the first inclination angle are configured to provide an increased air flow through at least some of the openings proximate the front edge, to provide an increased air flow toward the door. relative to the air flow through a region of the first inclined screen portion. 
     
     
         11 . The refrigerator of  claim 1 , wherein the first thickness, first area and number of first openings and the first inclination angle and dimensions of the first inclined screen portion within a perimeter region are configured to provide an increased air flow through at least some of the openings that are within the perimeter region. 
     
     
         12 . The refrigerator  claim 1 , wherein the first inclined screen section is coupled to a second inclined section having a second inclination angle greater than the first inclination angle and extending downwardly from the front edge toward the bottom, the second inclined section being comprised of a second thickness and second openings having a second area. 
     
     
         13 . The refrigerator of  claim 12 , wherein the first and second thicknesses are substantially the same and wherein the first and second areas are substantially the same. 
     
     
         14 . The refrigerator of  claim 12 , wherein the first and second thicknesses, the first and second areas and the first and second inclination angles are configured to provide an increased air flow through at least some of the first and second openings proximate the front edge, to provide an increased air flow toward the door. relative to the air flow through a region of the first inclined section. 
     
     
         15 . The refrigerator of  claim 1 , wherein the first duct portion has an inlet with a first cross sectional area and is coupled to a second duct portion having an outlet coupled to the inlet of the first duct portion and having an inlet, the second duct portion being configured to provide an air stream at the outlet of the second duct portion that flows into the inlet of the first duct portion, the air stream provided to the inlet of the first duct portion having a substantially uniform air flow distribution over the cross sectional area of the inlet of the first duct portion. 
     
     
         16 . The refrigerator of  claim 13 , wherein the air stream has a direction through the first and second duct portions and wherein the direction and the cross sectional area are substantially orthogonal. 
     
     
         17 . The refrigerator of  claim 14 , wherein the second duct portion has a converging section located between the outlet and the inlet of the second duct portion, the inlet of the second portion being coupled to a fan, the converging section being configured to evenly distribute an air flow from the fan, substantially uniformly across the cross sectional area of the outlet of the second duct portion. 
     
     
         18 . The refrigerator of  claim 13 , wherein the first duct portion and the second duct portion are comprised of separate duct sections, joined to each other at the inlet of the first duct portion and the outlet of the second duct portion. 
     
     
         19 . The refrigerator of  claim 13 , wherein the inlet of the second duct portion is located proximate to the top of the refrigerator cabinet, whereby refrigerated air flows upwardly from the first inclined screen portion into the inlet of the second duct portion. 
     
     
         20 . A method of circulating air in a refrigerator cabinet having first and second sides, a rear side, a front opening having a door, a top and a bottom, the method comprising the steps of:
 forcing air into a plenum located proximate to the bottom of the refrigerated cabinet, the plenum defined by a bottom, upwardly extending sides, an air input port coupled to an air duct and an inclined panel extending between the upwardly extending sides and facing upwardly toward the top of the refrigerator cabinet, the inclined panel having a thickness and perforated with a plurality of openings distributed across the inclined top panel, each opening defining an open area in the inclined panel through which air from below the inclined panel can pass and flow upwardly in the refrigerator cabinet, the thickness of the top panel, the number, open area and spacing of the openings and a flow rate of air driven into the plenum creating a positive pressure below the inclined panel that is greater than the pressure outside the plenum such that air in the plenum below the inclined panel flows upwardly through the plurality of openings and upwardly through the refrigerator cabinet;   collecting upwardly flowing air in the refrigerator cabinet at an inlet of a duct located near the top of the refrigerator cabinet; and   routing air collected at the duct inlet through the duct to an evaporator and from the evaporator back into the plenum.