Abstract
A shelf for a refrigerator is provided, the shelf comprising: a first surface for receiving items when the shelf is in use; the first surface being spaced apart from a second surface to form a duct between the first and second surfaces; wherein the duct allows fluid communication between an air inlet and an air outlet, the duct being flared to form the air inlet such that the cross sectional area of the air inlet is larger than that of the duct.
Claims
1. A shelf for a refrigerator, the shelf comprising: a first surface for receiving items when the shelf is in use; and a second surface spaced apart from the first surface to form a duct configured to channel air from an air inlet to an air outlet, the duct being flared such that the duct has a maximum a cross sectional area at the air inlet.
2. The shelf of claim 1, wherein at least a part of the air outlet is formed in the second surface of the shelf.
3. The shelf of claim 2, wherein at least a part of the air outlet is formed in an edge of the shelf that is opposite the air inlet.
4. The shelf of claim 1, further comprising a diverter that is positioned at and extends into the air outlet.
5. The shelf of claim 1, wherein the first surface is planar and the second surface is flared to form the air inlet.
6. The shelf of claim 1, wherein the first surface is flared to form the air inlet and the second surface is planar.
7. The shelf of claim 1, further comprising a blanking plate disposed above the first surface and extending in a direction that is away from the second surface.
8. The shelf of claim 1, further comprising a blanking plate disposed below the second surface and extending in a direction that is away from the first surface.
9. The shelf of claim 7, wherein the blanking plate extends away from a surface of the first shelf in the same plane as the air inlet.
10. A refrigerator comprising: a back wall of a refrigerated interior space, the back wall defining a perforation configured to expel cold air into the refrigerated interior space; and a shelf attached to the back wall, the shelf including a first surface for receiving items when the shelf is in use, and a second surface spaced apart from the first surface to form a duct configured to channel air from the perforation, through an air inlet, and to an air outlet, the duct being flared such that the duct has a maximum a cross sectional area at the air inlet.
11. The refrigerator of claim 10, wherein the perforation is a first perforation defined by the back wall, the refrigerator further comprising: a blanking plate disposed above the first surface of the shelf and extending in a direction that is away from the second surface of the shelf, the blanking plate covering a second perforation.
12. The refrigerator of claim 11, wherein the blanking plate is a first blanking plate, the refrigerator further comprising: a second blanking plate disposed below the second surface of the shelf and extending in a direction that is away from the first surface of the shelf, the second blanking plate covering a third perforation.
13. The refrigerator of claim 10, wherein the perforation is a first perforation defined by the back wall, the refrigerator further comprising: a blanking plate disposed below the second surface of the shelf and extending in a direction that is away from the first surface of the shelf, the blanking plate covering a second perforation.
14. The refrigerator of claim 10, wherein air in the refrigerated interior space is separated from air in a space exterior to the open display refrigerator by an air curtain established by a fan that blows air through an air curtain outlet towards a corresponding air curtain inlet which recovers air from the air curtain for recirculation to the air curtain outlet.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIG. 1 shows an open display refrigerator with conventional shelves.
[0033] FIG. 2 shows the airflow through an open display refrigerator with conventional shelves.
[0034] FIG. 3 shows an open display refrigerator fitted with shelves in accordance with an embodiment of the invention.
[0035] FIG. 4 shows the airflow through a shelf in accordance with an embodiment of the invention.
[0036] FIG. 5 shows a known, prior art, ducted shelf.
[0037] FIG. 6 shows how the air inlet of a shelf in accordance with an embodiment of the invention covers an enhanced number of perforations.
[0038] FIG. 7 shows the enhanced cooling of items stored in a refrigerator that uses a shelf in accordance with an embodiment of the invention.
[0039] FIG. 8 shows the enhanced cooling of items stored in an open display refrigerator that uses a shelf in accordance with an embodiment of the invention as well as airflow through the open display refrigerator.
DETAILED DESCRIPTION
[0040] FIG. 1 shows a cross-section through a conventional open display refrigerator 1. The refrigerator has an interior space which is maintained at a lower than ambient temperature. Within the interior space, there are five shelves 3 and a base. In use, the refrigerator 1 establishes an air curtain (as shown in FIG. 2) by blowing cold air from an air outlet 2 towards an air inlet 4. In use, air inlet 4 recovers air from the air curtain and at least one fan 5 within the refrigerator 1 recirculates the air to the air outlet 2 via a cooling heat exchanger 6 and a duct 8. The cooling heat exchanger 6 is typically placed within the refrigerator 1 and maintains the recirculated air (and hence the air blown through the air outlet 2 to form the air curtain) at a desired temperature below ambient temperature. In use, cooled air from the duct 8 also passes through the perforations in the perforated rear wall 7 of the refrigerator to help cool items stored in the refrigerator 1.
[0041] FIG. 2 shows the flow of air through the conventional open display refrigerator 1 of FIG. 1. In particular, the arrows in FIG. 2 shows how an air curtain 9 is established between the air outlet 2 and the air inlet 4 and how the at least one fan 5 within the refrigerator 1 recirculates the air to the air outlet 2 via a cooling heat exchanger 6 and a duct 8. Further, FIG. 2 shows how cooled air in the duct 8 (arrow 10) passes from the duct 8 and through perforations in the rear wall of the refrigerator (arrow 11). The air then passes over the shelves 3 of the refrigerator 1 (arrow 12) and finally, this air hen passes over the edge of the shelf 3 (arrow 13) and then down towards the air inlet 4. Air from the air curtain 9 prevents at least some of the air from exiting the refrigerator 1 via the open front of the refrigerator.
[0042] FIG. 3 shows an open display refrigerator 1 fitted with five shelves 14 in accordance with the present invention. Although shown attached to an open display refrigerator in this example, the shelves can be fitted to any refrigerator with a perforated wall through which air passes. The shelves 14 comprise an air inlet 15 which, in use, covers one or more perforations in the perforated rear wall 7. Although the figure shows the air inlet covering the height of two perforations, as discussed above, the perforations may be of any size. The shelves also comprise a flared portion 16, such that the air inlet has a larger cross section than the duct formed between a first surface 17 and a second surface 18 of the shelf 14. The flared portion 16 is shown as extending in a downwards direction towards the base of the refrigerator 1. Although not shown, it is contemplated that the flared portion 16 may alternatively extend in an upwards direction towards the top of the refrigerator 1 or there may be two flared portions that extend away from the shelf 14 in opposite directions.
[0043] In use, air flows through the perforations, through the air inlet 15, through the duct formed between the first 17 and second 18 surfaces and, optionally, out of an air outlet 19. Although not shown here, other arrangements are contemplated. If the shelf does not comprise the air outlet 19, air may circulate in the interior of the shelf and also leave through the air inlet 15. The shelf 14 also comprises an optional diverter 20 for directing air out of the air outlet 19. Also shown is an optional blanking plate 21 for covering perforations above the shelf 14. Although not shown, it is contemplated that the blanking plate 21 may extend in a downwards direction towards the base of the refrigerator 1 or the shelf may comprise two blanking plates extending away from the shelf 14 in opposite directions. The blanking plate 21 may be integral to the shelf or, alternatively, the blanking plate and the shelf may be provided separately as part of a kit for retrofitting to existing refrigerators. It is contemplated that shelves made in accordance with the present invention can be retrofitted to existing refrigerators with perforated walls. The shelves may be provided with tabs for slotting into a receiving portion in a refrigerator. The shelves may be provided with appropriate “male” and/or “female” attachment portions that are received by corresponding “female” or “male” attachment portions on the refrigerator wall in use. Alternatively, the shelves may be screwed or riveted onto the rear wall of a refrigerator in use.
[0044] FIG. 4 shows the airflow through a shelf 14 for a refrigerator in accordance with the present invention. As can be seen, in use, air passes through perforations in the perforated rear wall 7 (arrow 11). In use, the air passes through the duct formed by the first 17 and second 18 surfaces of the shelf 14 (arrow 22) and out of the air outlet 19. In use, the diverter 20 directs the air that passes out of the air outlet 19 in a downwards direction.
[0045] FIG. 5 shows a known ducted shelf 23 for a refrigerator (as described above). The known ducted shelf 23 differs from the shelf of the present invention in that the air inlet is not flared. Instead, the known ducted shelf 23 makes use of a diverter 24 to help collect air from a duct behind the rear wall 26 of a refrigerator. Air flows through the interior of the shelf (arrow 25) and out of an air outlet. As can be seen, it is difficult to retrofit such a ducted shelf 23 to a refrigerator with a standard perforated rear wall, as typically the perforations will not be large enough to receive the diverter 24. As such, the standard perforated rear wall would need to be replaced.
[0046] FIG. 6 shows the shelf 14 of FIG. 4. As indicated by the arrow proximate the air inlet 15, the flared portion 16 ensures that more perforations are covered than if the air inlet was the same height as the shelf, as in FIG. 5. This increase in covered perforations allows more cooled air to enter the interior of the shelf 14 and negates the need for the diverter shown in FIG. 5. As such, the shelf 14 can be retrofitted to existing refrigerators with perforated walls, because the air inlet simply covers the perforations and arrangement to receive a diverter (as with the known shelf shown in FIG. 5) is not needed.
[0047] FIG. 7 shows the shelf 14 of FIGS. 4 and 6 in use. As before, in use, cooled air flows from the duct and through perforations in the perforated wall 7 (arrow 11). In use, items 28a on the first surface 17 are cooled by the cooled air that passes through the interior of the shelf 14. In use, items 28b that are located on a shelf below the present shelf 14 are cooled by the cooled air that passes out of the air outlet 19 and directed by the diverter 20. This arrangement is more efficient that simply allowing air to pass through the perforations of the perforated rear wall 7, not least because this arrangement makes use of conduction as well as convection, in that the cold air cools the first surface 17 of the shelf and the cold first surface 17 conducts the heat away from the items 28a. The air outlet 19 and diverter 20 direct air onto items at the front of the shelf, which provides additional cooling which would not be achieved by air passing out of the perforations and over items on the shelf. Typically, items at the front of the shelf would be warmer than items at the rear of the shelf as they are further away from the perforations and hence the cooled air passing out of the perforations. As can be seen, in typical use, the flared portion does not interfere with the way a shelf is loaded as items are typically not loaded right to the rear of a refrigerator. FIG. 7 also shows how the blanking plate 21 deflects cooled air back into the duct and prevents it from exiting through perforations above the shelf. In use, this causes more air to exit through shelves that are located above the present shelf.
[0048] FIG. 8 shows an open display refrigerator fitted with shelves 14 in accordance with the present invention. As can be seen, in use, an air curtain 9 is established between the air outlet 2 and the air inlet 4. In use, cooled air passes from the duct 8 through perforations in the perforated wall 7, through the air inlets 15 of the shelves 14, through the interior of the shelves 14 and out of the air outlets 19 of the shelves 14. As shown in FIG. 7, in use, the shelves 14 cool items 28a placed on the first surfaces 17 of the shelves 14 by conduction and cool items 28b placed on the shelf below by directing cooled air onto the items 28b. As discussed above, in use, this provides more effective cooling than a conventional open display refrigerator and the shelves 14 are able to be retrofitted to existing refrigerators with perforated walls.
