HEAT TRANSFER SYSTEMS AND METHODS

Abstract

A heat transfer enclosure for receiving articles to be processed or stored under conditions of reduced temperature, comprising one or more members of thermally conductive material having a thermal conductivity of at least 10 Wm.sup.1 K.sup.1, the one or more members having a contact surface for contacting articles located in the enclosure and including projections extending generally away from the surface; wherein in use heat is conducted between an article contacting the contact surface with an upper surface of the article and a heat exchange fluid in the heat transfer enclosure via an articlecontact surfaceprojectionsheat exchange fluid heat transfer path.

Claims

1. A heat transfer enclosure for receiving articles to be processed or stored under conditions of reduced or elevated temperature, comprising one or more members of thermally conductive material having a thermal conductivity of at least 10 Wm.sup.1K.sup.1, said one or more members having a contact surface for contacting articles located in the enclosure and including projections extending generally away from said surface; wherein in use heat is conducted between an article contacting said contact surface with an underside or an upper surface of said article and a heat exchange fluid in said heat transfer enclosure via an articlecontact surfaceprojectionsheat exchange fluid heat transfer path.

2. The enclosure according to claim 1, further comprising means to convey said heat exchange fluid through said heat transfer enclosure past said projections.

3. The enclosure according to claim 1, wherein the projections are in the form of a plurality of ribs, fins or columns extending transversely to said contact surface; wherein the projections comprise an array of a plurality of parallel, spaced ribs.

4. (canceled)

5. The enclosure according to claim 1, wherein the projections are integral with and made of the same material as said contact surface.

6. The enclosure according to claim 1, wherein the contact surface is one of a planar surface or a substantially planar surface.

7. The enclosure according to claim 1, wherein the one or more members comprise a horizontally extending planar contact surface in the form of a shelf or tray on which an article can be placed to contact the underside of the article.

8. The enclosure according to claim 1, wherein the member is configured to be used with the contact surface in contact with the upper surface of the article.

9. The enclosure according to claim 1, wherein the member comprises a generally vertically extending contact surface configured to contact the side of articles.

10. The enclosure according to claim 1, wherein the member comprises a horizontal spacer having parallel, spaced apart horizontally extending contact surfaces, to be placed between articles stacked on top of each other, with projections extending between the contact surfaces.

11. The enclosure according to claim 1, further comprising a depressor arrangement to urge the article and contact surface into engagement.

12. The enclosure according to claim 1, wherein a first said member is inverted compared to an orientation of a second said member, wherein said second member is configured to engage with an article surface opposite to the surface of the article with which said first member engages, and wherein in use said first or second member applies a force to urge said article and said contact surfaces of said first and second members, respectively, into engagement.

13. The enclosure according to claim 1, wherein the member is fixed in position in the enclosure.

14. The enclosure according to claim 1, wherein the member is movable within the enclosure in use thereof.

15. The enclosure according to claim 1, further comprising a blast freezer, tunnel freezer, belt freezer, spiral freezer or helix freezer for use in batch, semi-batch or continuous mode.

16. A member for use in a heat transfer enclosure, the member being of thermally conductive material having a thermal conductivity of at least 10 Wm.sup.1K.sup.1 and comprising a contact surface for contacting an article located in the enclosure and projections extending generally away from said surface; wherein (i) the member is configured to be used with the contact surface in contact with an upper or lower surface of the article; or wherein (ii) the member comprises a horizontal spacer having parallel, spaced apart horizontally extending contact surfaces, to be placed in an interleaving configuration between articles stacked on top of each other, with projections extending between the contact surfaces.

17. (canceled)

18. A method of reducing or increasing the temperature of an article in a heat transfer enclosure, the article being in contact with a contact surface of a member of thermally conductive material having a thermal conductivity of at least 10 Wm.sup.1K.sup.1 that includes projections extending generally away from the contact surface, comprising contacting the projections with a heat exchange fluid at a lower temperature than the article for cooling or at a higher temperature than the article for heating, such that heat is conducted between said article contacting said contact surface with an underside or upper surface of said article and said heat exchange fluid in said heat transfer enclosure via an articlecontact surfaceprojectionsheat exchange fluid heat transfer path.

19. The method according to claim 18, wherein the article is in contact with a member configured for use in a heat transfer enclosure, the member being of thermally conductive material having a thermal conductivity of at least 10 Wm.sup.1K.sup.1 and comprising a contact surface for contacting an article located in the enclosure and projections extending generally away from said surface; and wherein the member is configured to be used with the contact surface in contact with an upper or lower surface of the article; or wherein the member comprises a horizontal spacer having parallel, spaced apart horizontally extending contact surfaces, to be placed in an interleaving configuration between articles stacked on top of each other, with projections extending between the contact surfaces.

20. The method according to claim 18, wherein the heat exchange fluid is conveyed past the projections.

21. The method according to claim 18, wherein the article and contact surface are urged into engagement with each other.

22. The method according to claim 18, wherein the member is fixed in position in the enclosure or wherein the member is moved within the enclosure.

23. (canceled)

24. (canceled)

25. (canceled)

26. (canceled)

27. (canceled)

28. (canceled)

29. (canceled)

30. (canceled)

31. (canceled)

32. (canceled)

Description

[0072] The invention will be further described, by way of illustration with reference to the accompanying drawings, in which:

[0073] FIG. 1 is a schematic end view of part of a member in accordance with embodiments of the invention supporting articles in the form of rectangular containers, with FIG. 1A being an enlarged scale fragment of region C illustrating heat flow;

[0074] FIG. 2 is a schematic end view of a member as shown in FIG. 1 in a heat transfer enclosure supporting articles in the form of rectangular containers;

[0075] FIG. 2A is a schematic perspective view of the arrangement of FIG. 1;

[0076] FIG. 3 is a schematic end view of a member and containers as shows in FIG. 2, with a further member in inverted condition located on the containers;

[0077] FIG. 3A is a schematic perspective view of the arrangement of FIG. 3;

[0078] FIG. 4 is a schematic end view of a member in accordance with embodiments of the invention in the form of a spacer located between layers of containers;

[0079] FIG. 4A is a schematic perspective view of the arrangement of FIG. 4;

[0080] FIG. 5 is a schematic end view of a further spacer in accordance with embodiments of the invention;

[0081] FIG. 6 is a schematic end view of a further spacer in accordance with embodiments of the invention;

[0082] FIG. 7 is a schematic graph of temperature versus time;

[0083] FIG. 8 is a schematic perspective view of a depressor arrangement in accordance with embodiments of the invention;

[0084] FIG. 9 is a schematic cut-out perspective view of an enclosure with a conveying means in accordance with embodiments of the invention;

[0085] FIG. 10 is a schematic perspective view of an arrangement in accordance with embodiments of the invention; and

[0086] FIG. 11 is a schematic end view of part of a member in accordance with embodiments of the invention supporting an article in the form of a rectangular container, with FIG. 11A being a schematic perspective view of the member of FIG. 11.

DETAILED DESCRIPTION OF THE DRAWINGS

[0087] The drawings are highly schematic, and not to scale, to illustrate representative members in accordance with embodiments of the invention.

[0088] The member 10 shown in FIGS. 1, 2 and 2A comprises a planar member 12 having an upper face 14 constituting a contact surface with an array of parallel, spaced apart elongate planar ribs or fins 16 constituting projections extending at 90 from the opposed face 18 of the member. The member is made of metal, e.g. aluminium. The fins may be integral with, or secured to, face 18. In a typical embodiment, the fins have a fin length (extending away from face 18) of 25 mm, a fin width of 0.3 mm and spacing between the fins of 2 to 8 mm.

[0089] The member 10 is for use in a heat transfer enclosure represented at 30 in FIG. 2, such as a freezer or chiller, with the member being shown secured in position within the enclosure by mountings 32, and with articles in the form of rectangular boxes 34 containing goods such as food products or foodstuffs to be chilled or frozen. In practice, a typical chiller or freezer enclosure would contain a plurality of members 10, which need not be fixed in position but which could be mechanically movable within the enclosure in use thereof in known manner, as in an automated carton freezer.

[0090] The member 10 is designed to be able to support the load of the articles with which it is intended for use.

[0091] In use of the enclosure, a heat exchange fluid, typically chilled air, is brought into contact with the fins 16, typically being caused to flow past the fins along the length thereof, in a direction perpendicular to the plane of the paper of the figures, e.g. under the action of a fan.

[0092] The fins 16 can be considered effectively to increase the surface area of the boxes 34 and so to enhance heat exchange across the member 12 and so promote cooling of the boxes 34, as discussed shove. The arrows of FIG. 1A illustrate this heat flow.

[0093] FIGS. 3 and 3A illustrates a further similar member 10 in position on top of the boxes 34, with heat exchange fluid also being caused to flow past the fins of member 10 along the length thereof in use.

[0094] FIGS. 4 and 4A illustrate an alternative member 40 in the form of a spacer having parallel planar upper and lower plates 42, 44 connected by an array of parallel, spaced apart planar ribs or fins 46 extending perpendicularly to the plates. The spacer member 40 is located between two layers of boxes 34. The spacer member 40 is made of aluminium and functions in the same manner as members 10 and 10, with heat exchange fluid flowing along the length of the fins 46 in use.

[0095] Optional corner or edge supports (not shown) may be provided extending between the plates to provide additional structural rigidity if required.

[0096] FIGS. 5 and 5A illustrates an alternative spacer member 50 formed from a sheet of metal, e.g. aluminium, deformed to produce a zig zag arrangement defining upper and lower planar contact surfaces 52, 54.

[0097] FIG. 6 illustrates an alternative aluminium space member 60 having parallel planar upper and lower plates 62, 64 the outer faces of which constitute contact surfaces connected by a regular array of columns 66 extending at right angles to the plates, the columns extending through and being connected to an array of spaced apart apertured plates 68 oriented to lie parallel to the plates 62, 64.

[0098] FIG. 7 is a schematic graph of temperature versus time showing changes in temperature over a 24 hour time period of an article to be frozen placed in a freezer enclosure on a conventional shelf and on a shelf in accordance with embodiments of the invention, with the upper line showing the profile for charges in the article core temperature on a conventional shelf and the line below showing the profile for a similar article on a shelf in accordance with embodiments of the invention. The two lower lines show profiles for changes in the temperature of ambient air (heat exchange fluid) in the enclosure, with the upper of these lines showing results using a shelf in accordance with embodiments of the invention and the lower line showing results for a conventional shelf. The ambient air temperature is higher with the shelf according to embodiments of the invention because more heat is extracted from the article, with higher efficiency. The article cools more quickly on the shelf according to embodiments of the invention compared with a conventional shelf (in both cases going through a relatively level temperature stage during the latent phase change state).

[0099] FIG. 8 is schematic perspective view of an arrangement 800. The arrangement has, in this example, a member 804 having projections extending generally away from the contact surface onto which article 802 is placed. The depressor member 806 exerts in this example a downward force (indicated by the arrow 808) onto the article 802 to urge the article 802 and contact surface of the member 804 into engagement. In this example, the depressor member 806 has projections generally extending away from its contact surface with which it contacts the article 802. This allows for further increasing heat transfer between the article 802 and, for example a heat exchange fluid, such as, e.g. an unconfined intervening fluid.

[0100] FIG. 9 shows a schematic cut-out perspective view of an enclosure 900 with a conveying means 904. In this example, the conveying means is a fan 904 which conveys the heat exchange fluid (which in this example is an intervening fluid, for example air) through the heat transfer enclosure 900 past the projections of the members 804 and 806, as indicated by arrows 906. This may allow for advantageously removing, for example heat from the article 802 more efficiently, i.e. at a higher rate. In this example, the arrangement for cooling the article 802 is identical to the arrangement of FIG. 8.

[0101] FIG. 10 shows a schematic perspective view of an arrangement 1000 for cooling articles 1002a, 1002b, 1002c and 1002d. The arrangement 1000 combines members shown, for example in FIGS. 1, 4, 5, and in some examples FIG. 6. In some examples, article 1002a may merely be used to function as a depressor to urge the articles 1002b, 1002c and 1002d and contact surfaces of respective members into engagement (as indicated by the vertical arrow 808). An intervening fluid can flow through the projections of the members 1004a, 1004b and 1004c, as indicated by arrows 1006. This embodiment may be combined with the conveying means shown in FIG. 9.

[0102] FIGS. 11 and 11A show a schematic end view and perspective view, respectively, of part of a member 1100 supporting an article 1102 in the form of a rectangular container. In this example, the projections 1104, which extend generally away from the contact surface of the member 1100 onto which article 1102 is placed, have a substantially L-shaped form. The projections are in some examples between approximately 0.25 and 0.35 mm thin, such that attaching the projections to a plate functioning as the contact surface onto which the article is placed may be difficult. Therefore, providing the projections with a substantially L-shaped form may advantageously allow for simplifying attaching the projections 1004 to the plate to form the member. This may further improve the stability of the member 1100.

[0103] In some examples, the projections 1104 are attached to each other, whereby a part of the L-shaped projection overlaps with a part of the neighbouring projection(s). A separate plate which may function as a contact surface for supporting an article may not be needed in this example.

[0104] The material of the projections 1104 may be chosen such that it is compatible with the material of a chip (or other device) onto which the member 1100 is placed. In some examples, the material of the projections 1104 and the chip is identical. The material may be, e.g. aluminium.

[0105] Further aspects of the invention are described in the following clauses: