WO1994008496A1

WO1994008496A1 - Cooled storage apparatus

Info

Publication number: WO1994008496A1
Application number: PCT/AU1993/000527
Authority: WO
Inventors: Ian Thomas George Mcgrath
Original assignee: King, Stephen, Lawrence
Priority date: 1992-10-14
Filing date: 1993-10-14
Publication date: 1994-04-28

Abstract

Apparatus for storing products comprising a number of shelves (62, 64, 66) within which chilled or heated water is circulated, the arrangement being such that products placed upon the shelves are cooled or heated by direct heat conduction between the products and the circulated fluid.

Description

COOLED STORAGEAPPARATUS

This invention relates to cool storage apparatus for storage of articles, products, or materials at low or high temperatures.

The present invention relates to cooled or heated storage apparatus particularly but not exclusively cabinets of the type which are used for displaying products in supermarkets or shops.

The general object of the invention is to provide novel storage apparatus which is relatively cheap to construct and operate and which provides flexibility in use.

According to the present invention there is provided cooled storage apparatus comprising a plurality of shelves and means for circulating a chilled fluid within the shelves whereby products placed on the shelves are cooled by heat conduction from the products to the chilled fluid.

Preferably, the shelves are arranged one above the other whereby products on the lower shelves are additionally cooled by convection currents from the upper shelves.

Preferably further, the chilled fluid comprises water having an anti-freeze agent therein.

The invention also provides cooled storage apparatus comprising a chiller for chilling a fluid, storage means for storing the chilled fluid, circulating means for circulating the chilled fluid to at least one display cabinet, and control means for controlling the flow of chilled fluid to said at least one cabinet.

Preferably, each of the cabinets is individually controlled. Preferably further, the chilled liquid comprises water having an anti-freeze agent therein.

Preferably further, the chiller is supplied from a mains supply and is arranged to operate during periods of low tariffs.

Preferably further, the chiller does not utilise CFCs such as the refrigerant R12. Preferably further, the chiller uses the refrigerant R22.

Preferably further, each cabinet has a three-way control valve for selectively controlling the flow of said circulating fluid from a supply line from the storage means, a return line to the storage means and a bypass line therebetween such that chilled water from the supply line is only introduced into the cabinet when the temperature within the cabinet exceeds a predetermined level.

The invention also provides a display cabinet for cool storage of products characterised in that the side walls and rear wall are formed from a single sheet of plastics material.

Preferably a plurality of shelves are connected to the rear wall along the rear edges of the shelves.

Preferably further, the ends of the shelves are received within manifolds which are adhered to the sidewalls of the cabinet, the manifolds being arranged to circulate a chilled fluid through the shelves.

The invention also provides storage apparatus comprising a plurality of shelves and means for circulating a heated fluid within the shelves whereby products placed on the shelves are heated by heat conduction to the products from the heated fluid.

The invention will now be further described with reference to the accompanying drawings, in which: ^• FIGURE 1 is a schematic view of cooled storage apparatus in accordance with the invention;

FIGURE 1A shows a preferred form of control valve; FIGURE 2 is a schematic side view through a storage cabinet of the invention; FIGURE 3 is a simplified plan view along the line 3-3;

FIGURE 4 is a more detailed view showing the connection of a shelf to a manifold;

FIGURE 5 is a schematic side view of an alternative embodiment of the invention.

The cooling apparatus 2 shown in Figure 1 comprises a chiller 4 which chills a circulating fluid supplied to it by a supply line 6. The circulating fluid preferably comprises water having an anti-freeze agent such as ethanol therein. If ethanol is used, it preferably comprises a 20% by volume solution so that the temperature can be reduced to about -10°C without freezing. The chiller preferably uses the refrigerant R22 which is normally used for air conditionings and is not traditionally used for cool rooms or refrigerators. The system of the invention, however, is arranged such that this refrigerant can be used and therefore the apparatus of the invention will pass regulations banning the use of CFCs which are being progressively introduced. The apparatus includes a pump 8 for pumping chilled water from the chiller 4 via supply line 10 to a thermally insulated tank 12. The chiller 4 can be arranged to operate at offpeak periods such as between 11.00pm and 7.00am so as to chill all of the water within the tank 12 to a predetermined temperature, say -10°C.

If during use of the apparatus the temperature in the tank exceeds a predetermined temperature the chiller 4 can be operated so as to return the water in the tank to the desired storage temperature, -10°C. It is thought, however, that if the capacity of the tank 12 is selected to match the load then the chiller 4 would need to be operated only rarely outside the offpeak periods. This of course enables much reduced running costs to be achieved.

Chilled water from the tank 12 is pumped by a circulating pump 14 to a supply line 16. The supply line 16 supplies chilled water to a plurality of cabinets 18, 20, 22 and 24 via input branch lines 26, 28, 30 and 32 respectively. Chilled water flows through the cabinets and then returns via branch return lines 34, 36, 38 and 40 to a main return line 42 which returns the chilled fluid to the top of the tank 12. The various supply and return lines can be provided with isolating valves or the like for selective removal of the cabinets and/or for provision of additional cabinets to be chilled.

Each of the cabinets includes a thermostatically controlled three-way valve 44 which is arranged to control the flow of chilled liquid therethrough. Figure 1A illustrates this for the first cabinet 18, the others being the same or similar. It will be seen that a bypass line 46 is connected between the supply branch line 26 and the return branch line 34 via the valve 44. A remote sensing element 48 is located in the cabinet or in the circulating system in the cabinet to control the valve 44. The valve 44 is arranged to dilute the water in the line 26 to the cabinet with return water from the line 34 such that the water is supplied to the cabinet at -1°C and water returning to the valve 44 via the bypass line 46 is at say 1°C. In this way the volume for the tank 12 can effectively be reduced thus making installation cheaper and reducing the flow rates of chilled water to be circulated by the pump 14. If the temperature sensed by the sensor 48 increases owing to increased cooling load in the cabinet 18, the proportion of chilled water at -10°C from the main supply line 16 is increased to thereby maintain the temperature of the chilled water delivered to the cabinet at the selected temperature, -1°C.

Each of the cabinets 18, 20, 22 and 24 has its own control valve and each can, if desired, be set at a different operating temperature. This of course affords considerable flexibility in the manner in which the apparatus is used.

Figures 2, 3 and 4 diagrammatically illustrate novel features of the cooling cabinet 18 of the invention. The cabinet 18 has sidewalls 50 and 52 and rear wall 54 integrally formed from a single sheet of plastics material such as extruded acrylic sheet, say 6mm in thickness. The material may for instance comprise PLEXIGLAS manufactured by Rohm GmbH. The frontal edges of the sidewalls 50 and 52 are formed with frontal face portions 56 and return legs 58. The frontal portions 56 and return legs 58 form internal channels 60 and 61, as best seen in Figure 3. The provision of the channels 60 and 61 contribute to the strength and appearance of the cabinet.

The cabinet 18 is provided with a number of shelves including a bottom shelf 62, intermediate shelves 64 and a top shelf 66. A layer of insulating material 67 is located beneath the lower shelf 64 for strength and thermal insulation. The layer 67 may comprise polyurethane or polystyrene foam say 30mm in thickness. The shelves are connected to the rear wall 64 by means of L-shaped acrylic brackets 68 which are permanently bonded to the rear wall 54 by means of a solvent based acrylic adhesive. As best seen in Figure 2, the brackets 68 are located beneath the intermediate shelves 64 and top shelf 66 but above the bottom shelf 62.

Each of the shelves 62, 64 and 66 is of hollow construction, that is to say is provided with a plurality of longitudinally extending ducts 63 through which the chilled water to the cabinet is arranged to pass. More particularly, the shelves can be made from a commercially available material known as double skin sheet PLEXIGLAS SDP14 "non drop" made by Rohm GmbH. This material is coated so as to prevent formation of droplets when water condenses thereon. It is preferred that other parts of the cabinet are similarly coated to prevent formation of droplets. The ends of the shelves are coupled to headers or manifolds 70 and 71 which are bonded to the sidewalls 50 and 52 of the cabinet. As best seen in Figure 3, the front ends of the manifolds 70 are received within and bonded to the channel 60 and the front ends of the manifolds 71 are received within and bonded to the channel 61. The manifolds perform two important functions, namely as part of the circulating system for chilled fluid but also add considerable strength to the cabinet.

As best seen in Figure 4, the manifolds 70 and 71 are preferably formed from extruded acrylic material which is of the same type as the shelves and sidewall, the material being extruded as a hollow square section having an outer size of say 50mm x 50mm. The inwardly disposed faces 72 of the manifolds are provided with slots 74 which receive the ends 76 of the shelves 62, 64 and 66. Acrylic adhesive material 78 is used to physically bond the shelves to the manifold and to form water tight seals therewith. The manifolds 70 connected to the sidewall 50 are interconnected by means of a vertically extending pipe 80 whereas the manifolds 71 connected to the sidewall 52 are connected to a vertically extending pipe 82. As best seen in Figure 4, the pipes 80 and 82 are provided with holes 84 within the manifolds so as to provide fluid communication therewith. The pipes are joined and sealed to the manifolds by means of acrylic adhesive bonds 86, as seen in Figure 4. The pipes 80 and 82 may comprise extruded acrylic pipes having an outer diameter of say 19mm. The pipes 80 and 82 are connected to the supply and return branch lines 26 and 34 respectively, the arrangement being such that the chilled water is circulated through the ducts which extend through the hollow shelves.

The cabinet is preferably provided with upper and lower illuminated signs 88 and 90.

A prototype cabinet has been tested and has been found to operate Satisfactorily with relatively low flow rates of chilled water through the shelves. For instance, for a typical display case for a supermarket of a width of about 2 metres, a volume of chilled liquid of the order of 0.2 litres per second for storage of products such as dairy products or the like. With these relatively low flow rates, flow through the shelves 62 is essentially laminar and therefore there is a generally uniform distribution of flow through the hollow ducts in the shelves. Thus there is no need for special steps to be taken to ensure equal distribution of chilled water through the various ducts of the shelves or from shelf to shelf.

Figure 5 is a schematic cross-section through a modified form of apparatus of the invention. This device includes a coil 100 and fan 102 to increase the cooling but is otherwise the same as the device illustrated in Figures 1 to 4. Accordingly, the same reference numerals are used to denote corresponding parts. • In Figure 5, the top shelf 66 is omitted and the coil 100 is fitted instead. The ends of the coil are connected to the chilled water supply and return pipes 80 and 82 so that chilled water flows through the coil 100. A fan 102 is provided above the coil so as to force air therethrough and significantly increase the cooling capacity in the top of the cabinet. The cabinet thus can be used as a freezer unit. Alternatively, the fan 102 can be used to ensure that there is more uniform circulation of chilled air within the cabinet.

It will be appreciated that the principles of the invention can be applied to other types of equipment where heat transfer takes place.

For instance, the shelves could be fabricated from aluminium or stainless steel or extruded from aluminium. Further, hot fluid such as water could be circulated through some or all of the cabinets to achieve heating of articles placed in the cabinets.

Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims

CLAIMS:

1. Cooled storage apparatus (2) comprising a plurality of shelves (62,64,66) and means (70,71,80,82,84) for circulating a chilled fluid within the shelves whereby products placed on the shelves are cooled by heat conduction from the products to the chilled fluid.

2. Apparatus as claimed in claim 1 wherein the shelves are arranged one above the other whereby products on the lower shelves are additionally cooled by convection currents from the upper shelves.

3. Apparatus as claimed in claim 1 or 2 wherein the chilled fluid comprises water having an anti-freeze agent therein.

4. Apparatus as claimed in any one of claims 1 to 3 wherein the shelves comprise extruded bodies having a plurality of ducts (63) extending therethrough and wherein the ends of the ducts are coupled to manifolds (70,71) for circulating the chilled fluid through the ducts.

5. Apparatus as claimed in claim 4 wherein for each shelf the manifold (70) at one end thereof is coupled to a chilled liquid supply line (80) and the manifold (71) at the other end thereof is coupled to a chilled liquid return line (82).

6. Apparatus as claimed in claim 5 wherein the liquid supply and return lines comprise supply and return pipes (80,82) which pass through the respective manifolds and wherein the supply and return pipes include holes (84) for fluid communication with the interior of the manifolds.

7. Apparatus as claimed in claim 4, 5 or 6 wherein the extruded bodies are extruded from plastics material.

8. ^* Apparatus as claimed in claim 7 wherein the plastics material comprises acrylic material.

9. Apparatus as claimed in any preceding claim including a coil (100), means for circulating the chilled fluid through the coil (80,82) and fan means for causing a flow of forced air adjacent to the coil to provide additional cooling.

10. Apparatus as claimed in any preceding claim including a cabinet (18) and means (68) for supporting the shelves in the cabinet.

11. Apparatus as claimed in claim 10 wherein the cabinet has sidewalls (50,52) and a rearwall (54) and wherein the sidewalls and rearwall are integrally formed from a sheet of plastics material.

12. Apparatus as claimed in claim 11 wherein frontal edges of the sidewalls (50,52) are integrally formed with strengthening channels (60,61).

13. Cooled storage apparatus (12) comprising a chiller (4) for chilling a fluid, storage means (12) for storing the chilled fluid, circulating means (8) for circulating the chilled fluid to at least one display cabinet (18,20,22,24), and control means (44) for controlling the flow of chilled fluid to said at least one cabinet.

14. Apparatus as claimed in claim 13 wherein each of the cabinets is individually controlled.

15. Apparatus as claimed in claim 13 or 14 wherein the chilled liquid comprises water having an anti-freeze agent therein.

16. Apparatus as claimed in claim 13, 14 or 15 wherein each cabinet comprises apparatus as claimed in any one of claims 1 to 12.

17.- Storage apparatus (2) comprising a plurality of shelves (62,64,66) and means (70,71,90,82,84) for circulating a heated fluid within the shelves whereby products placed on the shelves are heated by heat conduction to the products from the heated fluid.