Converging/Diverging Front Intake

Abstract

An air supply system for a refrigerator cabinet, which reduces temperature differences through-out the cabinet generates air currents in the cabinet by a panel that extends across the inside of the cabinet. The panel is set an angle that directs air downwardly and terminates with an upwardly-inclined air-diverting surface or baffle. The panel and baffle define a converging/diverging air intake for the air supply system, the input of which is located at the front of the refrigerated cabinet.

Description

BACKGROUND

Commercial refrigerator cabinets in common use today provide a refrigerated interior region with shelves that hold products to be sold. A problem with prior art commercial refrigerators is that it is difficult to provide uniform airflow within the cabinet. Air currents frequently develop such that regions of the cabinet are colder than others. A cool-air supply system that provides a more uniform cold air distribution within a refrigerator cabinet would be an improvement over the prior art.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a refrigerator cabinet;

FIG. 2 is a front elevation of the refrigerator cabinet shown in FIG. 1;

FIG. 3 is side view of the refrigerator cabinet shown in FIG. 1 and FIG. 2; and

FIG. 4 is a side view of the refrigerator cabinet depicting a converging/diverging front intake, which aids in the even distribution of refrigerated air flow in the refrigerator cabinet.

DETAILED DESCRIPTION

FIG. 1 is a perspective view of a refrigerator 100. The refrigerator 100 is comprised of a first or left side 101 (not visible in FIG. 1), a second or right side 102, a third or top side 104, a fourth or bottom side 106 (not visible in FIG. 1), a rear panel 108 and a front door 110. Wheels 112 attached to the bottom side 106 enable the refrigerator 100 to be rolled about. The front door 110 pivots on two hinges 114 located at and attached to the top edge 116 and bottom edge 118 of the door 110, which enable the door 110 to be opened by grasping a handle 120. The door 110 provides access to the interior of the refrigerator 100 where food items are to be refrigerated.

A thin, inclined, substantially planar air-diverting panel 150 is located inside the refrigerator 100 and fixed in the refrigerator 100. The panel 150 is mounted in the refrigerator at an angle relative to horizontal, which was empirically determined to aid in the deflection of air currents inside the refrigerator 100 and significantly reduce temperature differences through-out the refrigerator 100.

In a preferred embodiment, the panel 150 is made of thin sheet metal. In an alternate embodiment, the panel 150 is made of plastic. The panel 150 is preferably a solid sheet, however, in alternate embodiments the panel 150 is perforated with holes or slots.

The panel 150 is sized, shaped and arranged to extend from close to the bottom of the refrigerator and close to the door, inwardly and upwardly into the refrigerator 100 to a lower rear surface 152 of the interior of the cabinet. Stated another way, the panel 150 extends outwardly and downwardly from the lower rear surface 152 toward the bottom of the refrigerator, near the door 110.

When the panel 150 is viewed from the lower rear surface 152, the panel 150 appears to be declined relative to horizontal. Stated another way, the panel 150 is inclined at a negative angle relative to the lower rear surface 152. When the panel is viewed from the door 110, the panel is inclined relative to horizontal.

The panel 150 preferably abuts both the between the left side 101 and the right side 102 of the refrigerator 100. The panel 150 also extends almost all the way from its point of attachment to the lower rear panel 152 to the front door 110.

A downward-sloping portion of the panel 150 terminates or “ends” at an edge 154, best seen in FIG. 3, beyond which there extends a relatively short, inclined planar surface referred to herein as a “baffle” 156. The edge 154 constitutes a line of demarcation between the downwardly sloping panel 150 and the upwardly sloping baffle 156. Experiments show that the panel 150 formed with the edge 154 and baffle 156, reduce temperature gradients in the refrigerator. The panel 150, edge 154 and baffle 156 are believed to operate collaboratively to direct cold air currents in the cabinet upwardly in the cabinet. The panel 150, edge 154 and baffle 156 also define an air passage 158, which when viewed from the side converges to a narrow point just below the edge 154 and then diverges defining in the process, a venturi wherein air pressure is reduced.

FIG. 2 is a front elevation of the cabinet shown in FIG. 1. The panel 150 can be seen extending between and abutting the first or left side 101 and the second or right side 102 of the refrigerator 100. An air passage 158 exists in the open space between the edge 154 and bottom surface of the refrigerator 100.

An air circulation fan 200 is located proximate the top surface 104 of the cabinet. It is mounted in an upper back wall 202 of the refrigerator 100 and is configured with ducting to pull air through an evaporator coil (not shown) behind the back wall and into the refrigerator, i.e., toward the door. The fan 200 thus drives air into the interior of the refrigerator 100 creating a positive pressure inside the refrigerator 100 relative to the volume below the panel 150.

FIG. 3 is a side view of the refrigerator 100. The fan 200 can be seen mounted into the top portion of the upper back wall 202 to pulls chilled and therefore relatively dense air (identified by arrows labeled with reference numeral 304) through an evaporator 306 behind the upper back wall 202. The cold air 304 flows downwardly in the cabinet, i.e. towards the panel 150. When the cold air 304 reaches the panel 150, it strikes the panel 150, flows over the panel 150 toward the front edge 154 and toward the baffle 156. Since the baffle 304 is a solid or virtually solid surface, air 304, which continues to fall downwardly, is believed to curl upwardly from the baffle 156 in a counterclockwise rotation as shown by reference numerals 304. The curl of the air flow thus provides a turbulence, which deflects at least some of the air 304 upwardly in the cabinet.

Those of ordinary skill in the art will recognize that the cold and relatively dense air from the fan 200 creates a slightly positive pressure in the interior volume 306 of the refrigerator 100. Air flows into the fan 200 after being drawn through the evaporator 306. And, air flows into the evaporator from a duct 314 defined by the rear panels 152, 153 and 202 of the refrigerator 100. Air flows into the duct 314 from a plenum 316 formed by the sloping panel 150. Air flows into the plenum 316 from the interior 306 of the refrigerator 100 after passing through the narrow air passage 158 defined by the lower edge 154 and the bottom 106 of the refrigerator 100. The narrow air passage 158 defines a venturi. The duct 314 thus draws air from the plenum 316 and routes the air into the evaporator 306, back to the fan 200. The fan 200 thus acts as a cold air supply.

Those of ordinary skill in the art will recognize that the fan 200 creates a negative pressure inside the plenum 300, the duct 314, and the evaporator 306 at the same time that it creates a positive pressure inside the cabinet interior. Air 304 in the interior 306 of the refrigerator 100 thus eventually flows over the distal end 314 of the baffle 156, through the venture, continually circulating responsive to the fan 200.

Air that flows over the distal or farthest end 314 of the baffle 156 flows into a converging nozzle 320 formed by the baffle 156 and the relatively flat bottom surface 106. The converging nozzle 320 terminates at the lower edge 154 of the panel 150, which defines the aforementioned passage 158, which is also where the lower edge 154 creates the venturi. Air flows through the passage 158 and into the plenum 316 where the upwardly inclined panel 150 defines a diverging nozzle 322.

In tests of the refrigerated refrigerator 100, it was determined that the panel 150 improves cold air distribution in the interior 306 of the refrigerator 100. The upwardly inclined baffle 156 is believed to redirect air current as described above.

In the preferred embodiment, the panel 150 and baffle 156 are made from a single solid panel of thin sheet metal, which is stamped or folded to define the edge 154. Alternate embodiments include the use of a single panel of sheet metal that is stamped or rolled such that the edge 154 is actually curved or arcuate. Curved edges 154 include those which are substantially elliptic, substantially parabolic or substantially circular.

The panel 150 and baffle 156 are preferably made from a solid panel of sheet metal. Alternate embodiments use a panel 150 and baffle formed from perforated metal or plastics, perforations of which are so small as to be impervious or substantially impervious to air flow in order to have the panel 150 and baffle 156 be able to deflect air currents effectively.

The panel 150 and baffle 156 preferably extend all the way between the left side 101 and the right side 102 of the refrigerator 100. Alternate embodiments include the use of a panel and hence the use of a converging/diverging nozzle that does not extend all the way to the sides but instead leaves a small open space on one side, the other or both. Other alternate embodiments include the use of multiple panels, i.e., two or more panels, inclined at the same or different angles and mounted side-by-side each other in the refrigerated space.

The rear panels 152, 153 and 202 conduct or route air from the plenum 316 back to the evaporator 306. The rear panels 152, 153 and 202 thus define a warm air return duct. The warm air return duct thus effectively routes the air supplied by the fan 200 back to the evaporator.

Those of ordinary skill in the art will recognize that when the fan 200 is operating and drawing air through the passage 158 near the front door 110, a low pressure zone exists in front of the passage 158. The door 110 thus prevents the induction of warm room air into the plenum 316 and to the evaporator 306. In order to improve thermal efficiency, in one embodiment, an interlock switch is operatively coupled to the door 110, the switch being configured to shut-off power to the blower 200 whenever the door 110 opens.

The panel 150 is fixed in the refrigerator 100 at an angle of approximately negative 15 degrees relative to horizontal, with the origin of the angle being defined by the intersection of the panel 150 with the lower rear surface 152 of the cabinet. The negative fifteen degree angle was determined experimentally due to the fact that food storage shelves, commonly used in refrigerated cabinets are inclined at an angle of approximately fifteen degrees. The fifteen degree angle of the panel 150 thus conforms to the inclination of storage shelves used in the refrigerator 100. Alternate embodiments of the cool air supply system that is depicted in the figures and described above have panels fixed at steeper and flatter angles. In one extreme, the panel 150 can be inclined at about negative 80 degrees up to about positive 80 degrees.

As shown in the figures, the baffle 156 is inclined relative to horizontal at an angle of approximately 30 degrees, the origin of that angle being at the front edge 154 of the panel 150. Alternate embodiments include having a baffle 156 at angles that are between about zero degrees and vertical or 90 degrees relative to horizontal.

Those of ordinary skill in the art will recognize that the panel 150 and baffle 156 define an angle between them. As shown in the figure, the panel 150 and baffle 156 define an angle between them of about 120 degrees. Alternate angles between those two structures range from about just under 180 to 90 degrees.

The foregoing description is for illustration purposes. The scope of the invention is set forth in the appurtenant claims.

Claims

1. An air supply system for a refrigerator cabinet, the refrigerator having an interior defined by first and second sides, a rear side, a front opening, a top and a bottom, the air supply system comprising:

at least one panel extending between the first and second sides of the interior and extending from proximate the rear side of the interior toward the front opening, the at least one panel having a front edge proximate the front opening and having an inclined surface that extends upwardly from the front edge at an angle, the at least one panel, front edge and baffle defining an air passage proximate the front opening.

2. The air supply system of claim 1, wherein the at least one panel and the bottom of the refrigerator cabinet comprise a converging/diverging nozzle.

3. The air supply system of claim 2, wherein the converging/diverging nozzle extends substantially all the way between the left and right sides.

4. The air supply system of claim 3, further comprising:

an evaporator configured to cool air passing through the evaporator;

fan configured to move air through the evaporator; and

a warm air return duct that carries air between the converging/diverging nozzle and at least one of the fan and the evaporator.

5. The air supply system of claim 4, wherein the warm air return duct is comprised of the at least one panel and an interior surface of the refrigerator.

6. The air supply system of claim 4, wherein the cabinet is further comprised of a door, pivoting on a hinge proximate to one of the left and right sides of the cabinet.

7. The air supply system of claim 6, further comprising:

a blower, configured to move air through the cabinet; and

a switch operatively coupled to the door, the switch being configured to disable the blower when the door is open.

8. The air supply system of claim 1, wherein the at least one panel is fixed at a first angle, relative to horizontal.

9. The air supply system of claim 8, wherein the first angle is between about negative ninety degrees to about positive ninety degrees.

10. The air supply system of claim 1, wherein the baffle is at a second angle, relative to horizontal.

11. The air supply system of claim 10, wherein the second angle is between about zero degrees and ninety degrees, relative to horizontal.

12. The air supply system of claim 1, wherein the at least one panel is fixed at a first angle relative to horizontal, the baffle is inclined at a second angle relative to horizontal, the panel and baffle defining a third angle between them, the third angle being between zero degrees and ninety degrees.

13. The cool air supply system of claim 1, wherein the at least one panel is perforated.

14. The cool air supply system of claim 13, wherein the at least one panel is perforated and wherein the at least one perforated panel is substantially impervious to air.

15. The cool air supply system of claim 1, wherein the at least one panel abuts at least one of the left and right sides.

16. The cool air supply system of claim 1, wherein the at least one panel abuts the rear surface.

17. The cool air supply system of claim 1, wherein space between front edge, the baffle and the bottom define a venturi.

18. A method of circulating air in a refrigerator having an interior with first and second sides, a rear surface, a front, a top and a bottom, the method comprising the steps of:

driving cold air into the interior; and

collecting warm air through a converging/diverging nozzle located proximate the bottom, the converging/diverging nozzle being comprised of the bottom and, a panel located between the first and second sides and extending from proximate the rear surface of the interior toward the front opening, the panel having a front edge proximate the front opening and having a baffle extending upwardly from the front edge at an angle.

19. The method of claim 18, wherein the converging/diverging nozzle extends substantially all the way between the first and second sides.

20. The method of claim 18, further comprising the step of:

returning warm air to the cold air supply through a duct connected between the converging/diverging nozzle and the cold air supply.