NZ260339A - Refrigerated display cabinet: dual airflow above and below food trays - Google Patents

Description

Patents Form# 5 Priority Datev's): 3.0*1.33.,..

Compile Spv»cKtc:<«:dn F«?ad: .'•aSi.: (.v)..0.4:5.£2>|,cas}> i)Joo; ...Ess.x>.n.|.«?^.;.....f:.?.§..???..i Publication Date: 2-6--J-U.L- .1936.. !'\0. .Journal No: ,;s> o\\ f ^ !n iU-.- £ \ 18 APR 1994 g NF.W 7F,AT,AND Patents Act 1953 COMPLETE SPECIFICATION Refrigerated Cabinet We, Noble Australia Pty Limited, an Australian company, of 2 Greg Chappell Drive, Burleigh Gardens Estate, Queensland 4210, Australia, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement: The following page is numbered "la" FF05JWP FEE CODE -1050 26 0 3 3 la A refrigerated cabinet for preserving and displaying foodstuffs, the cabinet supporting rows of trays which carry the foodstuffs an providing a cool air flow both over the trays and under the trays to cool the foodstuffs from above and directly cool the trays. The cabinet may also include an overhead duct through which cool air flows to create an air curtain over the trays.

The following page Is numbered "lb" Ztj U -3 lb Technical Field THIS INVENTION relates to a method and means for chilling which may be embodied in a refrigerated cabinet or unit and in particular in a refrigerated display cabinet of 5. the type for displaying fresh foods in a restaurant or retail environment. The present invention also relates to a method and means for draining refrigerated cabinets or units.

Background Art It has become common place for restaurants, shops or other food outlets to provide refrigerated cabinets in which foods to be consumed such as salads, fruit or meat are displayed for selection either by patrons or shoppers. For preserving such foodstuffs the refrigerated cabinets usually employ some means for maintaining the containers for the foodstuffs at a low temperature so as to prevent their deterioration. Generally, however, the refrigerated cabinets which have been proposed in the past have not proved particularly 20 efficient so that the foodstuffs stored and displayed are not sufficiently protected from deterioration. Additionally, some of the refrigerated cabinets often do ' not satisfy health authority requirements.

In the above type of cabinets, usually a 25 considerable amount of condensation occurs and drains are provided to drain the condensed water into a tray provided with a heating element so that the water is evaporated. Often however the drain also directs spilt food into the tray which, when subject to heating from the heating 30 element, deteriorates and creates a hygiene problem. Difficulties in flushing and cleaning cabinets of the above type also occur. A further disadvantage arises because the drain also tends to direct warm air back to the chilling part of the cabinet which reduces the chilling efficiency. 35 Summary of the Invention The present invention aims to overcome or alleviate the above disadvantages by providing a method and means for chilling or cooling for the purposes principally 260339 of preserving foodstuffs from deterioration. The method and means of the present invention in a particular aspect may be incorporated in a refrigerated cabinet or unit which ensures that food or other product stored and displayed therein is protected against deterioration. The present invention also aims in a 5 preferred aspect to provide a unit in which the displayed food or product is readily accessible to consumers. The present invention in yet a further preferred aspect aims to provide a refrigerated cabinet or unit having means which allow for effective draining of condensed moisture and additionally enables more rapid cleaning and flushing. The present invention in a further preferred aspect aims to 10 provide a unit incorporating a drainage system which prevents warm air being directed back to the chilling part of the cabinet so that the chilling efficiency of the cabinet remains substantially unaffected by the drainage system. Other objects and advantages of the invention will become apparent from the following description.

The present invention thus provides a refrigerated cabinet or unit including an upper wall, said wall having a plurality of spaced apart openings therein, a plurality of spaced apart removable open top trays for carrying foodstuffs or other products to be chilled, said trays being supported by said upper wall and being received in respective said openings, an air chamber on 20 the underside of said wall and said trays, first air outlet means on one side of said trays and comprising first air outlet means disposed above the upper level of said trays for directing air over the top of said trays and second air outlet means adjacent to but disposed below said first air outlet means for directing air to and about the underside of said trays, air inlet means on the side of said tray opposite 25 said first and second air outlet means, air cooling means and air circulating means, said air circulating means being adapted to draw air in through said air inlet means and cause said air to pass through said air cooling means for cooling of said air a rui further cause said cooled air to be forced through said first-and second air outlet means to flow in a direction towards said air inlet means and 30 above and below said trays for cooling or chilling said tpjsc^nd-the contents 3 260339 thereof from above and below.

The trays suitably have side walls and a base which extend into the chamber so as to be cooled by the cooled air flow for the second air outlets. The air cooling means is suitably arranged within a passage below the 5 trays, the passage communicating at one end with the air inlet means and the chamber at its other end with the air circulating means such that air from the inlet means and the chamber is drawn through the air cooling means by the circulating means. The passage may be defined by a wall above the cooling means, the wall defining the base of the chamber.

The cool air flow suitably passes above the passage towards the one end of the passage and is drawn into the passage and through the air cooling means.

The circulating means suitably comprise one or more fans and the air cooling means suitably comprise refrigeration coils. The refrigeration coils 15 are suitably associated with a refrigeration unit located in the base of the cabinet.

In one particularly preferred arrangement, means for establishing a further cool air flow are provided, being arranged above the trays to direct a cool air flow downwardly towards the air inlet means and thereby create an air curtain over the trays. Duct means are suitably disposed above the 20 trays and include outlet means through which the further cool air flow may pass downwardly toward the air inlet means.

Suitably, the duct means comprises an elongated elevated duct having a plurality of outlets through which air may flow. The duct is preferably supported at each end by further upright ducts which provide 25 communication with a cold air source. The upright ducts are suitably connected to a generally horizontal duct or channel extending longitudinally of the cabinet or unit. The horizontal duct includes the aforesaid air outlet means which are suitably in the fonn of slots or alternative apertures through which the cooled air flows. The horizontal duct or channel may extend centrally and longitudinally of 30 the cabinet or unit with the trays located on opposite sides thepeSSfjfflTfie duct of /V h *12JUN1996 *j I? t 26 0 3 3 9 the channel may include the air outlets on opposite sides for directing cooled air above and below the trays on opposite sides of the duct or channel.

A canopy may be supported over the overhead duct to extend on opposite sides thereof. If desired lighting elements may be provided on 5 opposite sides of the overhead duct to illuminate the foodstuff supporting means.

The trays for the foodstuffs are thus directly cooled from underneath by the cold air flow from the second air outlets wliilst the cold air flow from the fust outlets passes over the top of the trays to further enhance the cooling effect on foodstuffs within the trays and thereby isolate the trays from the ] 0 temperature of the outside atmosphere.

The fan or fans also preferably circulate cool air through the central elevated duct and for this purpose are suitably located adjacent the lower end of the upright ducts. The upright support ducts for the elevated duct may also be provided with air outlets for directing cool air downwardly and outwardly to the 15 ends of the unit which may also include air inlets to draw in the air for cooling.

In an alternative configuration the further air flow establishing means may be provided on one side only of the unit to create a curtain of air on one side, such as from the rear of the cabinet downwardly over the trays. In this arrangement only one row of trays may be provided. In an 20 alternative configuration further or alternative ducts may be provided to extend at least part way around the perimeter of the cabinet at an elevated position, the ducts having air outlets to create an air curtain to the air inlets about the trays.

The present invention provides in a further preferred aspect in a refrigerated cabinet or unit, a base and drain means for draining liquid or 25 other materials from the base and seal means within the drain means permitting liquid and other materials to pass through the drain means but preventing the passage of air through the drain means. Most preferably, the drain means drains liquid or other materials into a holding tank which may be provided with an outlet which extends to a position externally of the unit so as to permit drainage 30 of the tank to waste. Preferably, the outlet is provided with a removable cap i ^ 0 *Ci\ U { *2JUN 1990^1 V*.%- 260 3 3 y which is externally accessible and which may be removed to permit liquid and other materials to be drained into say a bucket or the like.

Preferably, the seal means comprises a liquid seal and for this puipose, the drain means preferably incorporates a trap containing liquid which 5 acts as a seal. The liquid in the trap thus permits drain liquids to pass to waste or to the holding tank but acts as a seal to prevent hot air passing back through Hie drain means which would reduce the chilling efficiency. The trap suitably is in the form of a P-trap.

Alternatively, the drain means may drain directly through the liquid 10 seal to an external waste such as a floor waste in the vicinity of the cabinet.

Brief Description of the Drawings In order that the invention may be more readily understood and put into practical effect, reference will now be made to the accompanying drawings which illustrate a preferred embodiment of the invention and wherein:-15 Fig. 1 is a perspective view of a first form 6 26 0 3 3 of display and cooling unit of a refrigerated cabinet according to the invention with one foodstuff tray removed; Fig. 2 is a schematic plan view of the unit of 5. Fig. 1 showing the preferred location of the fans; Figs. 3 and 4 are partial cross-sectional views of the cabinet in the longitudinal and transverse directions; Fig. 5 illustrates portion of the central duct of 10 the cabinet with fan removed; and Figs. 6 and 7 illustrate alternative forms of refrigerated cabinet according to the invention. Detailed Description of the Embodiments Referring to the drawings and firstly to Figs. 1 15 to 4 there is illustrated a refrigerated cabinet 10 according to one form of the present invention including a casing 11 which is normally supported on a ground or floor surface and which includes a refrigeration unit 12 associated with refrigeration coils 13. Supported on or 20 formed with the casing 11 is a display and cooling unit 14 which in this embodiment includes a pair of spaced apart troughs 15 divided by transversely extending dividers 16, the troughs 15 being adapted to receive a number of pans or trays 17 in a single level on either side of the cabinet 10 25 for carrying food stuffs to be displayed and dispensed. As is conventional, the trays or pans 17 are provided with peripheral supporting flanges 18 to enable their support on upper edges of the troughs 15 and are removable to allow for emptying or refilling the contents of the trays 17. 30 Extending longitudinally of the cabinet 10 and between the troughs 15 is a hollow elongated duct 19 of generally rectangular section form and having in its opposite side walls 20, upper and lower rows 21 and 22 of air outlets in this instance in the form of slots/23,/ the rows 21 and 22 35 being disposed above and below the^Crays 17 respectively. The duct 19 additionally incorporates a longitudinally extending horizontal dividing wall 24 (see Fig. 5) arranged below the lower rows 22 of slots 23. A pair of spaced apart 26 0 3S 7 fans 25 are supported on the wall 24 adjacent openings 26 through the wall 24 to draw air upwardly in the manner described further below. Further upright wall portions 27 are provided below or comprise extensions of the duct side 5. walls 20 and include a longitudinally extending row 28 of openings or slots 29.

The cooling unit 14 at its opposite longitudinal sides is provided with air inlets in the form of longitudinally extending rows of slots 30 arranged adjacent 10 the upper level of the trays 17. Further air outlet openings or slots 31 may also provided in opposite end walls 32 of the duct 19 and air inlets 33 may be provided at opposite ends of the cooling unit 14.

The opposite sets of refrigeration coils 13 are 15 disposed beneath a horizontal wall 34 which is aligned with or comprises an extension of the wall 24 and which forms with an insulated base wall 35 of the cooling unit 14 opposite passages 36 in which the coils 13 are located. The air inlet openings 30 communicate with the lower side 20 of the wall 34 and thus the passage 36 and coils 13 on their outer side whilst the coils 13 on their inner sides communicate with the duct 19 and the fans 25 through the slots 29 in the rows 28 and openings 26.

The duct 19 may be provided with a pair of 25 opposite longitudinally extending baffles 37 (see Fig. 5) which separate the slots 23 in the upper rows 21 from direct communication with the fans 25. The baffles 37 are provided with a series of openings 38 v»hich limit air flow to the slots 23 in the upper rows 21. This will ensure 30 that the velocity of air flowing outwardly of the slots 23 in the upper rows 21 is reduced and will undergo a tumbling action from the outlet slots 23 to the inlet slots 30 on the outer side of the cabinet 10.

Supported on the duct 19 is an overhead duct 35 assembly 39 including an elongated generally horizontal overhead duct 40 spaced above and extending longitudinally of and generally parallel to the duct 19 and joining, or formed integrally at each end with upright ducts 41 which CO U J 8 are mounted at spaced apart positions to the duct 19 adjacent the fans 25 and communicate with the interior of the duct 19.

The end ducts 41 are provided with a plurality of Ej outlet openings 42 so as to direct cold air downwardly towards the inlet openings 33 provided at opposite ends of the unit 14. The central overhead duct 40 is provided with a series of openings 43 on its underside for directing air downwardly on both sides over the trays 17 and towards the 10 inlets 30 on opposite sides of the unit 14, this air undergoing a generally tumbling motion.

In use and during operation of the fans 25 external air will be drawn in through the inlets 30 to pass through the refrigeration coils 13 to thus be cooled and be 15 drawn into the duct 19 through the rows 28 of slots 29. The cooled or chilled air is then forced by the fans 25 out through the outlet slots 23 in the lower rows 22 to pass about the underside of the trays 17 and then be drawn back through the cooling coils 13 as indicated by the arrows in 20 Pig. 4. The cool or chilled air is also forced out through the outlets 23 in the upper rows 21 (via the baffles 37 where used) to flow over the trays 17 in a tumbling manner to cool from the upper side and be drawn in through the inlets 30. Further chilled air is forced 25 upwardly through the upright ducts 41 to pass out of the openings 42 and the overhead duct 40 to pass out through the openings 43 down towards the inlets 30 and 33 to create an air curtain to insulate the region about the tray 17 from the outside atmosphere. The entire products held 30 within the trays 17 and thus encased in air whilst the trays 17 are subject to the cooling or chilling effect of the air flowing both above the trays 17 and below and around the trays 17.

The cabinet 10 is preferably provided with a 35 canopy 44 arranged above the overhead duct 40 and extending on opposite sides and ends thereof to constrain the air flow in and around the trays 17. The canopy 44 is preferably formed of a transparent material such as perspex. Lighting elements 45 may be provided on opposite sides of the overhead duct 40 to extend longitudinally thereof for illumination of the trays 17 and their contents. 5i In an alternative version of the cabinet 10 of the invention as shown in Fig. 6, the overhead duct 40 may be provided to the rear of the cabinet 46 which effectively comprises half of the cabinet 10 to create an air curtain on one side only of the cabinet 46 which in this embodiment 10 includes only a single row of trays 17. Of course, in this embodiment, or in the embodiment of Figs. 1 to 4 more than one row of pans or trays 17 may be used.

In yet an alternative embodiment the overhead duct 40 may be extended either partially or fully around 15 the perimeter of the unit 14 for example as at 47 to direct cold air downwardly towards the inlets 30 and 33 and create an air curtain about the periphery of the unit 14. In this arrangement the central overhead duct 40 may be eliminated.

The outlet and inlet openings may be of any 20 form such as slots, apertures or the like. In the embodiments illustrated, the openings are provided in rows. The inlet openings 30 and 33 are preferably arranged on an inclined angle directed upwardly as shown in Fig. 4 to improve air collection, however they may be in a horizontal 25 plane. The inlet openings 30 and 33 are preferably in the form of slots.

In some embodiments the overhead duct assembly 39 is eliminated with the full chilling effect achieved in this instance by the cold air flow above and below the 30 trays 17 as previously described.

A drain assembly 50 (see Fig. 3) is preferably provided in the cabinet 10 to drain condensed liquids or other substances from the cabinet 10 for cleaning purposes. The drain assembly 50 includes an inlet 51 which opens 35 through the base wall 35 to receive liquid say which condenses along with other waste materials such as spilt food which collects beneath the trays 17. To direct such materials to the inlet 51 of the drain assembly 50, the - o U 6 6 base wall 35 may be inclined say by being creased from opposite sides and ends of the cabinet 14 towards the inlet 51. The inlet 51 is connected to a trap 52 in this embodiment in the form of a P-trap which forms a liquid 5 seal 53. The outlet side of the trap 52 is directed into a holding tank 54 so that liquid and other materials passing through the inlet 51 are collected. The holding tank 54 is provided with an outlet duct 55 which extends to the outside of the cabinet and which is provided with a 10 removable end cap 56.

In use, any liquid collecting on the base wall 35 of the cabinet 10 is directed towards the inlet 51 to pass through the trap 52 for collection in the tank 54. At the same time, air within the cabinet 10 which is usually hot 15 air due to it being heated by the refrigeration unit 12 is prevented by the trap 52 and the liquid seal 53 therein from passing back up the inlet 51 into the chilling unit 14 of the cabinet. Thus cooling efficiency of the cabinet 10 is maintained.

For drainage purposes, the cap 56 is removed at regular intervals so that the contents of the tank 54 may be drained say into a bucket or the like for disposal. Additionally, a flushing or cleaning liquid when used to clean the cooling unit of the cabinet 10 is also directed 25 by the base wall 35 to the inlet 51 into the holding tank 54 for drainage into a bucket or other similar container for discharge. At the end of the cleaning process, the cap 56 may be replaced so that liquids or other materials may again collect in the holding tank 54.

The drain assembly 50 described above has been shown in combination with a specific design of refrigerated cabinet. The drain assembly 50 however may be used with ) any form of refrigerated or other cabinet where drainage of condensed liquid and other materials and/or flushing 35 liquids is required. The drainage assembly 50 may be incorporated at any position in a cabinet to collect condensed water or flushing liquids and of course depending upon the design of cabinet, more than one drainage assembly t " A 7 11 " ' 0 50 may be provided. In some instances also, the holding tank 54 may be eliminated and the outlet of the trap 52 directed to an external drain such as a floor waste for example by a duct 55 (shown in dotted outline in Fig. 3.

. The trays 17 for supporting the foodstuffs may be of any suitable form and in the embodiment illustrated of shallow dish-like form. The trays 17, however, may have a deeper configuration or alternatively be in the form of a planar shallow body. The trays may also be fixed in 10 position or formed integrally in the unit or cabinet. The trays are suitably formed of metal suitably stainless steel.

Whilst the above has been given by way of illustrative embodiment of the invention, all such 15 modifications and variations thereto as would be apparent to persons skilled in the art are deemed to fall within the broad scope and ambit of the invention as herein defined in the appended claims. 9c f! " 0 i™ w u 0 12

Claims (16)

1. A refrigerated cabinet or unit including an upper wall, said wall having a plurality of spaced apart openings therein, a plurality of spaced apart removable open top trays for carrying foodstuffs or other products to be chilled, 5 said trays being supported by said upper wall and being received in respective said openings, an air chamber on the underside of said wall and said trays, first air outlet means on one side of said trays and comprising first air outlet means disposed above the upper level of said trays for directing air over the top of said trays and second air outlets adjacent to but disposed below said first air outlet 10 means and communicating with said chamber for directing air to said chamber and about the underside of said trays, air inlet means on the side of said trays opposite said air outlet means, air cooling means and air circulating means, said air circulating means being adapted to draw air in tlirough said air inlet means and cause said air to pass through said air cooling means for cooling of said air 15 and further cause said cooled air to be forced tlirough said first air outlets to flow in a direction towards said air inlet means for cooling or chilling said trays and the contents thereof from above, and through said second air outlets into said chamber and about the underside of said trays for cooling said trays from below. 20

2. A cabinet or unit according to Claim 1 wherein each said tray comprises a shallow tray having side walls and a base which extend into said chamber to be exposed to cool air flowing tlirough said second air outlets into said chamber. 25

3. A cabinet or unit according to Claim 2 wherein said air cooling means is arranged in a passage below said trays, and wherein said air circulating means is adapted to draw in air through said air inlet means and cause said air to be passed through said passage for cooling thereof. 30

4. A cabinet or unit according to Claim 3 wherein^ffi^^spge is A* v ^ 12 J UN 1998 •*** A 13 defined by a wall above said cooling means, said wall defining the base of said chamber.

5. A cabinet or unit according to any one of Claims 1 to 4 and 5 including substantially horizontal elongated duct means adjacent said trays, said elongated duct means including said air outlet means.

6. A cabinet or unit according to Claim 5 wherein said elongated duct means includes a side wall and wherein said air outlet means comprise 10 openings in said side wall.

7. A cabinet or unit according to Claim 5 or Claim 6 wherein said air circulating means comprise one or more fans. 15

8. A cabinet or unit according to Claim 7 wherein said duct means includes an internal substantially horizontal dividing wall below said air outlets and wherein said one or more fans are supported on said dividing wall.

9. A cabinet or unit according to any one of the preceding claims 20 and including means for establishing a further cool air flow from a position spaced above said trays to said air inlet means to provide an air curtain over said trays.

10. A cabinet or unit according to Claim 9 and including elevated 25 duct means located above said trays and including air outlet means, said elevated duct means communicating with a source of cool air whereby said cool air may be directed tlirough said air outlet means in said elevated overhead duct means towards said air inlet means to establish said further cool air flow. 30

11. A cabinet or unit according to Claim 10 wherein sayj^j^ited 14 260339 duct means is supported at each end by upright duct means which communicate said cool air to said elevated duct means.

12. A cabinet or unit according to Claim 5 wherein said horizontal duct 5 means extends longitudinally and centrally of said cabinet or unit, said trays being arranged on opposites sides of said horizontal duct means, and wherein said outlet means in said horizontal duct means directs cool air above and below said trays on opposite sides of said duct means. 10

13. A cabinet or unit according to any one of the preceding claims and including a base wall below said air cooling means and drain means connected through said base wall for draining liquids therefrom, said drain means including a liquid seal. 15

14. A cabinet or unit according to Claim 13 wherein said liquid seal is formed in a trap.

15. A cabinet or unit according to Claim 13 or Claim 14 and including a holding tank for receiving liquid from said drain, said holding tank 20 having an outlet arranged externally of said unit.

16. A refrigerated cabinet or unit substantially as hereinbefore described with reference to Figs. 1 to 5, Fig. 6 or Fig. 7 of the accompanying drawings. JAMES W PIPER & CO Attorneys for the applicant Noble Australia Pty Limited i*. t V teJUNl996 *J