WO1979000063A1

WO1979000063A1 - Container for cold subliming solids used in garments

Info

Publication number: WO1979000063A1
Application number: PCT/GB1978/000006
Authority: WO
Inventors: A Rowe
Original assignee: Individual
Current assignee: Individual
Priority date: 1977-07-25
Filing date: 1978-07-25
Publication date: 1979-02-22
Anticipated expiration: 1980-01-25
Also published as: GB2036346A; ZA774469B

Abstract

A container (20) for cold subliming solids (22) comprising insulating material (24), (26) and being characterised in that the insulating material (24), (26) is so arranged that there will be a greater heat exchange taking place through a part thereof in a selected direction than in other directions. The container may be used in garments for miners.

Description

COLD SUBLIMATING SOLIDS This invention relates to cold subliming. solid such as solid carbon dioxide and to containers therefor.

It is known to use solid carbon dioxide blocks for cooling workmen, the blocks being contained in articles of clothing such as jackets, jerkins and the like. Typical examples wherein such an arrangement as described include my U.S. Patent Specification No. 3,802,215 dated 9th April, 1974 and U.S. Patent 3,950,789 to S.A. Konz et al dated 20th April, 1976 (hereinafter referred to as Konz). In . Konz, the carbon dioxide block is contained within a container formed of "air bubble" material.

By "air bubble" Material is meant a commercially available insulating material which is formed from two laminated layers of plastic, one of the layers being provided with air bubbles and which is described in, inter alia, U. S. Specification 3,405,020 to Marc A Chavannes dated 8th

October, 1968. The plastic layer containing the bubbles comprise a base and bubbles formed thereon, there being flat portions between the bubbles, which flat portions are herein called "the field" and in referring to the field reference is being made not only to the flat portions of layer containing the bubbles, but the adjacent portions of the other layer.

In Konz the container for the carbon dioxide block comprises two layers of a sheet of air bubble material and is sealed at the sides having an open upper end. Sublimating carbon dioxide gasses must pass up to the opening and then escape from the container. Further the heat exchanges through the container are equal on both sides of the container.

An object of the invention is to provide a more satisfactory container for solid carbon dioxide blocks to be used in cooling clothing.

According to present invention there is provided a container for cold subliming solids comprising insulating material and being characterised in that the insulating material is so arranged that there will be greater heat exchange taking place through a part thereof in a selected direction than in other directions. The insulating material preferably comprises at least partially of "air bubble" material. This "air bubble" material is preferably a foraminous material being punctured between the bubbles to permit the subliming gasses to pass therethrough. Such punctures are preferably small perforations of the size of pin pricks. The container may be wholly formed by the air bubble material and in such an arrangement, the apertures are conveniently provided in one part only of the container. In addition reflectant means may be provided on one side of the container to inhibit heat exchange through that side.

According to another aspect of the invention, there is provided the combination of a container as set forth therein with a block of cold subliming solid therein.

An embodiment of the invention will now be described by way of example with reference to the accompanying drawings.

In the drawings:- Figure 1 is a section through a container including solid carbon dioxide in accordance with the invention,

Figure 2 is a similar section of another container including solid carbon dioxide of the indention, and

Figure 3 is a diagrammatic perspective view of an article of clothing in which the arrangement of Figure 1 or 2 can be used, being a partly inside and a partly outside view.

Container 20 closely bounding a block of solid carbon dioxide 22 and comprising two sheets 24 and 26 of a laminated cellular material known as "air bubble material" which are welded together at their edges. Each sheet of air bubble material may be as described with reference to Figure 11 of the abovementioned patent to Chavannes comprises a base sheet 28 and laminated thereto a second sheet 30 in which are formed many cells containing air bubbles 32.

The bubbles 32a on the sheet 24 are larger than the bubbles on sheet 26. Thus, sheet 24 has greater insulating properties than sheet 26. The sheet 24 is a foraminous sheet i.e. small perforations 34 in the form of pin pricks are provided in the field i.e. between the bubbles 32b through the sheets 28 and 30. A layer of reflectant material (indicated in dotted lines at 36) may be provided adjacent or laminated to the base sheet 28 of the cellular sheet 26. This provides additional insulation at this sheet.

If desired, and as an alternative to the foregoing, a separate sheet of reflectant material may be inserted between the cellular sheet 26 and the carbon dioxide block 18. The reflectant sheet serves to assist the features of the container mentioned above to ensure that the bulk of the heat transfer takes place through the cellular sheet 24 which has the smaller air bubbles and the pin prick apertures therethrough.

In use, the carbon dioxide block 22 is heated by heat conduction through the environment through the container 10. This heating causes the carbon dioxide to sublime. The sublimation gasses pass through the perforations in the foraminous sheet 24. Heat is also conducted to the block 22 through the slow moving sublimation gasses passing through the foraminous sheet 24. This achieves utilisation of the sensible heat cooling available in the sublimating gasses. There will be a much less amount of heat transfer through the sheet 26. This will provide the most efficient use of the cooling effect of the carbon dioxide block 22.

The bubbles 28 are conveniently on the outside of the container 20, but they could be on the inside as shown in Figure 2 which shows a modified container 20a wherein the same reference numerals are used for the same parts but are distinguished by the suffix "a".

The containers 20 and 20a may with advantage be used in mining applications with an article of clothing as will be described below and here the air bubble construction shows certain advantages, viz the thickness of the air bubbles is sensitive to air pressure, the insulation properties of the air bubbles are dependent upon their thickness and the termal conductivity of the air is essentially insensitive to pressure. This means that as the container is subject to increased pressure at depths within a mine, the thickness of the air bubbles is reduced as is the insulating effect of the air bubble material. Thus the rate of sublimation from the carbon dioxide block will be regulated in dependance upon the depth of the container within the mine.

It will also be noted that by providing an excess number of cells 28 so that increased insulation is provided, the insulation can be reduced by puncturing some of the air bubbles 28 prior to the use of the container.

Further both the containers mentioned above are inexpensive, to manufacture and thus are disposable. They provide sufficient insulation to permit the carbon dioxide to be handled without the person holding the blocks being "burned" on his bare hands. The insulate the carbon dioxide until it is ready for use, thereby reducing waste of coolant. Both provide a suitable support for the carbon dioxide in the event that the block may facture. Reference is now made to Figure 3 wherein is shown a garment for use by miners to utilize the containers 20 and 20a. The garment illustrated is a jerken 40. This jerkin 40 comprises a square of heavy industrial nylon having an opening 42 through which the head of a wearer can pass. pair of rods 44 extend along the sides of the front 46 and rear of the jerkin and strings 47 extend from eyes 48 at the ends of the rods 44 to secure the jerkin in position on the wearer. On the inside of both the front and the rear of the jerkin 40 is a pair of pockets 52. The upper open ends of the pockets 52 are closable by "Velcro" strips 34. Received in each .pocket 52 is a container containing a block of solid carbon dioxide. The container is either the block 20 or the block 20a. described above. The container is located in the pocket 52 in such a way that the foraminous sheet will be closer to the body of the wearer. Thus, the subliming gasses escape therefrom towards the body of the wearer, and serve to cool the body of the workman

Additional insulation is provided by a sheet of water impervi plastics material 50 sewed on to the outside of the jer n over the pockets. Insulating material, such as down (not shown) is packed between the nylon material of the jerkin and the water impervious material 50. Thus material 50 will protect the insulating material against water or damp and will further direct the subliming gassesagainst the body of the wearer. It will be noted that as the jerkin comprises woven nylon the fibres do not swell when subjected to the passage therethrough of the subliming gasses or by the water in the atmosphere. The woven cloth therefore does not clog to prevent the movement of the subliming gasses through the porous woven nylon cloth.

It will also be noted that the subliming gasses being dry will also additionally cool the wearer .by evaporative cooling.

The wearer preferably wears a vest under the jerkin to protect against the coolness of the gasses. However, as the sublimating gasses passing through the nylon are heated by the air passing towards the carbon dioxide, there is improved thermal efficiency of the operation and the carbon dioxide gasses will not be excessively cold when they reach the body of the wearer.

The wearer preferably also wears a thick cotton jacket over the jerkin while working. The cotton jacket mentioned is conveniently that widely used in the mining industry and known as a "pneumonia jacket". This jacket will assist in directing the subliming gasses against the body of the wearer.

It will be seen that as the direction of the subliming gasses by the construction of the container, the jerkin can be made without using the water impervious material. Thus the jerkin can be made from relatively inexpensive material. Such a jerkin can be discarded after a certain amount of use. Additionally it can be relatively light and it will not unduly interfere with the movement of the wear er. ^;

In yet a further modification, the jerkin which would otherwise be similar to the above, may have pockets on the outside. These pockets may be comprised by water impervious material or plain material as desired.

The garment can also be a poncho or a jacket. Further it will be noted that the drawings are diagrammatical in character so that, for example, the thickness of the air bubble sheets is grossly exaggerated and the number of bubbles shown and their size is minimal as compared to what would be seen in an exact drawing. However, the exaggeration is used in order to illustrate more clearly the invention.

The foraminous air bubble material may be put to other uses, for example, in the construction of light weight sleeping bags or clothing.

Claims

1. A container for cold subliming solids comprising insulating material and being characterised in that the insulating material is so arranged that there will be greater heat exchange taking place through a part thereof in a selected direction than in other directions.

2. A container as claimed in claim 1 characterised in that the insulating material is air bubble material.

3. A container as claimed in claim 2 characterised in that the air bubble material if foraminous material.

4. A container as claimed in claim 3 in which the container is wholly formed from air bubble material characterised in that only the air bubble material forming the said part is foraminous material.

5. A container as claimed in claim 3 or 4 characterised in that reflectant means is provided on one side of, the con- . tainer to inhibit heat exchange through that side.

6. A cooler pack comprising a container as claimed in any one of the previous claims with a block of cold sublimating solid therein.

7. A pack as claimed in claim 6 characterised in that the cold subliming solid is solid carbon dioxide.

8. A garment having pockets thereon and within the garment a cooler pack as claimed in claim 6 or claim 7, the part of the garment which in use is closer to the wearer comprising gas impervious material characterised in that the said part of the container faces towards the wearer when thegarment is in use

9. A garment as claimed in claim 8 characterised in that it wholly comprises gas permeable material.

10. A container substantially as hereinbefore described with reference to and as illustrated in Figure 1 or 2 of the accompanying drawings.

11. A garment substantially as hereinbefore described with reference toand as illustrated in Figure 3 of the accompanying drawings.

12. A garment as claimed in claim 11 modified as described herein.

13. A sheet of foraminous air bubble material as hereindefined.