GB2300469A - Chilling cartons - Google Patents

Abstract

In the chilling of ice cream or frozen desserts in cartons (6) carbon dioxide stored in a store (1) under conditions of low temperature and high pressure is released under ambient conditions to convert to the solid phase to produce dry ice. The dry ice is directed via a chute (3) to a support (2) on which a container (5) holding cartons (6) is supported to fill interstices (7) between adjacent cartons. Product is thereby chilled from inside the container rather than outside thus facilitating the chilling process and reducing required static cold store capacity.

Description

CHILLING APPARATUS AND METHOD The present invention relates to chilling apparatus and method of chilling.

The apparatus and method are particularly but not exclusively applicable to the chilling of ice cream and frozen desserts. Currently ice cream after being made and packed has a temperature of approximately 2 to -41/2OC. For storage purposes it is necessary to reduce this temperature to approximately -150C. This may be achieved by blast freezing with nitrogen. However blast freezing apparatus is expensive and bulky. The normal alternative to this is to stack the product on pallets and deposit the stacked pallets in a cold store. Not only does this occupy expensive store room capacity reaching the desired low temperature can take up to ten hours and this can adversely affect the products by causing the production of crystals. This is partly due to the chilling process taking place from outside.

The material of the packaging, usually cardboard, acts as an insulator keeping the heat in each individual pack and outer packs prevent heat escaping from packs on the inside of a stack.

According to one aspect of the present invention there is provided a method of chilling including the steps of placing a plurality of products to be chilled in a container with interstices therebetween, supporting the container and products on a surface with the container open to its upper side, depositing carbon dioxide as a solid in the container, distributing the carbon dioxide deposited so that it enters the interstices, closing the container and allowing the carbon dioxide to vaporise to lower the temperature of product in the container.

In a preferred embodiment of the invention, the container comprises a carton made of cardboard or other suitable material. The product is deposited at the end of the production process into tubs which are then placed in the carton leaving interstices between adjacent tubs. At the end of the production process the temperature of the product which may be ice cream, frozen dessert or other similar product may be approximately -40C.

Normally the desired storage temperature is -150C and sufficient carbon dioxide is deposited in the carton to achieve this reduction in a time period of thirty minutes or less. This reduces the possibility of ice crystals forming in the product which might adversely affect the product. After the carbon dioxide is deposited in the carton and the carton closed, the closed cartons are stacked on a pallet to allow chilling to take effect as the carbon dioxide evaporates. Depending on transport and delivery arrangements it may not be necessary for the stacked pallets to be placed in a static cold store at all.

Even if placed in a static cold store, however, the storage time will normally be less resulting in a reduction of cold store capacity for a given production rate. The amount of carbon dioxide required per carton will depend upon the amount of product in the carton given the temperature of the product at the start and finish of the chilling process and the temperature of the carbon dioxide.

In order that the invention may be more clearly understood, one embodiment thereof will now be described, by way of example, with reference to the accompanying drawings, in which: Figure I shows diagrammatically one form of apparatus according to the invention, Figure 2 shows a container to be chilled to a larger scale, and Figure 3 shows a plurality of containers of the sort shown n Figure 2 closed and stacked on a pallet.

Referring to Figure I, liquid carbon dioxide is supplied from a store I, where it is stored under conditions of low temperature and high pressure.

These storage conditions are such that, on release under ambient conditions, the liquid carbon dioxide converts to the solid phase to produce dry ice.

This is then directed down towards a support 2 via a chute 3 on which a container in the form of a carton 5 of tubs 6 is supported. An on/off valve 4 in the outlet from the store I controls the flow of carbon dioxide from the store I. The solid but particulate carbon dioxide (dry ice) is directed into the plurality of interstices 7 formed between adjacent tubs 6 of ice cream, frozen dessert or other appropriate product disposed in the carton 5. The carton 5, which is usually made of cardboard and has flaps 8, is then closed and stacked on a pallet 9. This process is repeated until the pallet is full. As compared with current conventional chilling methods, the chilling source is deposited within each carton to be chilled.Accordingly chilling medium does not have to penetrate the walls of the carton which has a greater or lesser insulating effect depending upon the material from which the carton is made. Furthermore, the insulating shield effect of outer cartons in a stack on inner cartons is avoided. The carbon dioxide temperature, when it is delivered to the carton will usually lie in the range -80 to .90or. As the carbon dioxide evaporates, the temperature of the product in the carton is lowered. The time taken for the product in the carton 5 to reach the desired temperature of -150C will vary depending upon the amount of product and quantity of carbon dioxide delivered.For a carton 5 containing six large or 24 small size tubs, one half kilogram of carbon dioxide is delivered and the time taken for the temperature of the product to reduce from -40C at the end of the production process to the desired storage temperature of -150C is approximately thirty minutes.

This much shorter chilling time compares with a chilling time of approximately ten hours required by chilling conventionally in a cold store.

Not only does this reduce possible deleterious effects on the products, cold store capacity may also be reduced with consequent savings in space and expenditure. In some cases it may be possible for chilling simply to take place on the pallet without having to be placed in cold store at the place of manufacture.

It will be appreciated that the above embodiment has been described by way of example only and that many variations are possible without departing from the scope of the invention.

Claims (9)

1. A method of chilling including the steps of placing a plurality of products to be chilled in a container with interstices therebetween, supporting the container and products on a surface with the container open to its upper side, depositing carbon dioxide as a solid in the container, distributing the carbon dioxide deposited so that it enters the interstices, closing the container and allowing the carbon dioxide to vaporise to lower the temperature of product in the container.

2. Apparatus as claimed in claim I, in which liquid carbon dioxide is stored under conditions of low temperature and high pressure so that on release the liquid carbon dioxide converts to the solid phase to produce dry ice.

3. Apparatus as claimed in claim I or 2, in which the means for directing carbon dioxide comprises a chute.

4. Apparatus as claimed in claim I, in which a valve is provided downstream of the storage of carbon dioxide to control the flow of carbon dioxide to the support.

5. Apparatus for chilling substantially as hereinbefore described, with reference to the accompanying drawings.

6. A method of chilling including the steps of placing a plurality of products to be chilled in a container with interstices therebetween, supporting the container and products on a surface with the container open to its upper side, depositing carbon dioxide as a solid in the container distributing the carbon dioxide deposited so that it enters the interstices, closing the container and allowing the carbon dioxide to vaporise to lower the temperature of product in the container.

7. A method as claimed in claim 6, in which sufficient carbon dioxide is deposited in the container to lower the temperature of the products to less than -150C in the time of thirty minutes or less.

8. A method as claimed in claim 6 or 7, in which a plurality of containers are stacked together.

9. A method of chilling substantially as hereinbefore described with reference to the accompanying drawing.