GB2040167A

GB2040167A - Air treatment device

Info

Publication number: GB2040167A
Application number: GB8002079A
Authority: GB
Original assignee: TRADEX
Current assignee: TRADEX
Priority date: 1979-01-26
Filing date: 1980-01-22
Publication date: 1980-08-28
Also published as: FR2447221B1; BE881346A; IT1130900B; DE8001946U1; FR2447221A1; GB2040167B; IT8019389A0

Abstract

An air treatment device, primarily a deodoriser for use in a refrigerator, comprises a receptacle containing a predetermined charge of a treatment substance, such as activated charcoal comprising a hollow central body 1 having an annular peripheral flange 4, 4' at each end arranged to clip into a groove formed in a corresponding end cap or plate 2, 3 to hold the plates on the body 1. Two foil elements 7 and 7' with a high permeability to air, a high resistance to humidity, and capable of retaining particles of the order of a micron, are held between the end plates and the corresponding ends of the central body. Each end plate has apertures 6, 6' to allow air to permeate into and out of the body through the foils, the activated charcoal being retained in the body by the foils. The charge is such that it fills the body 1 to the horizontal median plane when the receptacle rests on its side, and in this way ensures the largest possible contact surface area between the air to be treated and the charge. <IMAGE>

Description

SPECIFICATION Air treatment device The present invention relates to an airtreatment device of the kind comprising a receptacle which allows the air to be treated to pass through it and into contact with a substance contained in the receptacle for effecting the desired treatment. The substance may be solid, in block or granular form, or may be fluid, in the form of a gel, liquid or paste.

Such a device may have any one of a number of different functions such as a humidifier, a dehydrater, a disinfectant, a deodoriser or an air freshener, or a distributor or perfume or insecticide, but the invention is particularly concerned, although not exclusively, with a device for use in a refrigerator with a view to fixing the odours and thus preventing the migration of odours from foodstuffs to other foodstuffs.

Various forms of air treatment devices are known including devices for the adsorption of odours, but in general there is some disadvantage which has meant that they have not become as widely accepted by the public as perhaps they might. In particular, an odour adsorption device is known consisting of a hermetically sealed metallic receptacle formed by crimping a bottom and a cover on a section of tube, the receptacle containing a granular air treatment substance, such as activated charcoal, disposed loosely in the receptacle. To render the device operative, the user is obliged to make perforations in the receptacle by means of an appropriate tool, such as a punch or the like, but this operation is not without certain disadvantages. First of all, because of this preliminary operation, the device cannot be used immediately.Then, there is a risk of accidental injury arising from the tool used in making the perforations, and moreover, the perforations may not be made in the optimum manner. Either they may be too small or inadequate in number, which may hamper a satisfactory circulation of the air, or they may be too large and a certain amount of the treatment substance, particularly if it is activated charcoal in granular form, may escape from the receptacle with possibly harmful, and certainly annoying, consequences. Also, the receptacle is not re-usable and has to be thrown away when its contents no longer function.

Furthermore, the manufacture of the device necessitates various operations: manufacture of a receptacle with a bottom fixed by crimping or in some other sealed manner; introduction into the receptacle of a predetermined charge of activated charcoal; then hermetically fixing the cover in position by crimping or the like. The more manufacturing operations there are, the greater the cost of production.

A deodorising device is also known consisting of a receptacle which is generally spherical in shape and which is provided with apertures for permitting the passage of the air, the receptacle being contained in an envelope of foil material. This device also has a certain number of disadvantages. First of all, as in the previous case, the device cannot be used until perforations are made in the envelope, such as by means of a pin or a needle, the perforations registering with the apertures in the receptacle.

Although the risk of accidental injury is less than in the previous case, there is still the disadvantage that the perforations either may be too small or inadequate in number, which compromises a satisfactory circulation of the air, or may be too large in which case the contents can escape. Also, if the charge of treatment substance, in this case activated charcoal, becomes overloaded with humidity,for example during defrosting, this humidity affects the behaviour of the envelope which may tear and release the particles of activated charcoal. Consequently the manufacturers of such devices recommend the user to withdraw them from the refrigerator during defrosting. Finally, as in the previous case, after the device no longer works the receptacle is not reusable, either to permit a refill charge to be disposed therein orto be adapted to a different use.

According to the present invention we propose an air treatment device comprising a hollow body containing a charge of a substance for effecting the desired treatment of the air, the body having a pair of openings at opposite ends thereof, each of which is closed by an air permeable foil held across the opening by an end plate which is attached to the body and which is provided with apertures for the passage of air into and out of the body, the charge occupying only a portion of the internal volume of the body so as to facilitate the shaking of the charge and the renewal of the contact surface between the air and the charge.

By using as the charge a polyvalent substance, such as activated charcoal, for absorbing or adsorbing odours, a deodorising device is obtained which does not suffer the disadvantages of the prior devices described above. In particular, an air treat- ment device is provided which is simple to manufacture, is long lasting and consequently more economical, permits the use of refill charges, and is generally more effective than the known devices.

Also, the receptacle itself need not be thrown away after use, but may be used for other purposes if desired.

The hollow body may be tubular in shape, having any transverse external shape, e.g. polygonal, or consisting of a series of arcs, or of a combination of arcs and straight lines, and likewise any suitable internal cross-section. Preferably the hollow body is a body of revolution, the external generatrix being a straight line (producing a cylinder or a frustrum of a cone), or having the shape of a concave or convex arc to produce a diabolo or barrel shaped body respectively. The internal generatrix may have any general shape but, for obvious reasons of production, it is preferably straight so that the interior is cylindrical.

The body may be made of any suitable material such as metal or plastics, and by any suitable process, such as by moulding, stamping, or plastic deformation.

The end plates will generally be made of the same material as the body, but may be made of a different material if desired. They may be made by moulding, stamping, plastic deformation, or any other suitable way, the apertures for the passage of air being formed as an integral part of the manufacture or being formed subsequently by a punching or cutting operation.

The end plates may be fixed to the ends of the body, such as by an adhesive bond, but preferably the end plates are attached to the body in such a way that they can be removed and replaced when desired. For example the plates can be arranged to clip on to the ends of the body, or alternatively they can be arranged to be screwed on.

The foils consist of a material having a high permeability to air, which encourages an optimum circulation of the air, but nevertheless retains the charge of the air treatment substance in the body.

Preferably the foils also have a very high resistance to humidity. The foils may be clamped between each of the end plates and the corresponding end of the body. The foils may be stuck to the end plates or to the ends of the body. Alternatively each foil may be disposed in a removable manner in the corresponding end plate, the periphery of the foil being located in a groove in the end plate.

The charge of air treatment substance is preferably placed loosely in the body in such a manner that the centre of gravity of the device is below its horizontal median plane, which means that the device always adopts a position of stableequilibrium when it rests on its side on a horizontal surface.

in particular, the charge fills the body preferably to about the level of the horizontal median plane, so that the contact surface between the air to be treated and the treatment substance is as large as possible, thus ensuring an optimum treatment effect of the air.

Preferably the air treatment substance is activated charcoal in loose granular form.

A preferred example of the device in accordance with the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a longitudinal section through the device, showing the end plates slightly spaced from the ends of the body to which they are to be attached; and, Figure 2 is a view showing the body in side elevation, and showing the end plates in end elevation and detached from the body.

The device, which is generally designated by the reference R, comprises a central hollow body 1 made of expanded or lightened polystyrene, although any suitable plastics or metal could be used. This central body 1 has a shape of revolution, formed by an external generatrix in the general form of a convex arc, which gives it the general configuration of a small barrel having a number of peripheral circumferentially extending ribs. For reasons of production, the interior of the body 1 is in the form of a straight cylinder. At each of its two ends the body 1 has a peripheral annular flange 4, 4' which is arranged to be a snap fit in a corresponding annular groove 5, 5' formed in a cap-like end plate 2, 3 designed to fit on to the end of the body. The end plates 2 and 3 are made of the same material as the central body 1 for practical reasons, but this is not essential.The plates 2 and 3 are provided with apertures 6 and 6' for the passage of air. In the present case the apertures are in the form of parallel slots, but may be of any shape provided the total area thereof is fairly large for reasons explained below. An oblong diametral aperture could be provided of dimensions which would permit the subsequent re-use of the empty receptal cle R as a money-box.

Foil elements 7 and 7' are provided of such a ' shape and size that they can be retained between the ends of the central body 1 and the corresponding end plates 2 and 3 when the plates are fitted on the body. If desired these foil elements 7, 7' may be arranged to fit into the grooves 5 and 5' respectively.

The foil elements 7, 7' are made of a fabric which is permeable to air and resistant to humidity, and which is capable of retaining the particles of activated charcoal which will be introduced into the body as described later. Such a fabric may be a non-woven fabric of polyester, such as Reemay R manufactured by the Dupont Company of Nemours.

This fabric is permeable to air and is endowed with an exceptional resistance to humidity. It is also capable of arresting particles of very small dimensions of the order of a micron. It goes without saying that any other non-woven fabric having generally the same properties as indicated above would likewise be suitable.

As mentioned earlier, the apertures 6 and 6' formed in the end plates should have the largest possible area so that the contact area between the air and the particles in the plane of the foil elements is as large as possible, with a view to ensuring an optimum supplementary treatment effect of the air.

In order to make the receptacle R, the end plate 2 is first fixed to the central body 1, the foil element 7 being interposed between the end plate 2 and the corresponding end of the central body, by clipping the flange 4 into the groove 5. Then the receptacle, orientated vertically, is filled with a predetermined charge of granulated activated charcoal 8, and the end plate 3 is fixed by clipping the flange 4' into the groove 5' so that the foil element 7' is interposed between the end plate 3 and the corresponding end of the central body 1. The device so formed is intended for use as a deodoriser particularly for use in refrigerators. As will be seen from Figure 1 the predetermined charge 8 is such as to approximately half fill the interior of the body 1, i.e. so that it reaches the level of the horizontal median plane when the device is resting on its side.

Instead of providing flanges 4 and-4', it is possible to provide on the ends of the central body 1 projections distributed over the periphery and designed to penetrate into the grooves 5 and 5' of the end plates by being deformed elastically.

It should be noted that when the device is in a refrigerator, the vibrations caused by the motorcompressor assembly may be communicated to the granular charge of activated charcoal to cause a certain stirring of the particles in such a manner that the contact surface between the air and the charcoal charge is constantly renewed and these particles participate more completely in the treatment of the air. This stirring effect may be intensified by the shocks which occur when the door of the refrigerator is opened and closed. This beneficial advantage is not found in the known devices in which the charge of activated charcoal occupies the whole interior volume of the envelope or substantial part of the internal volume of the metallic receptacle, thus preventing a relative stirring of the charge which is thus not used in an optimum manner.Only those particles close to the external surface of the charge contribute intensively to the treatment of the air.

When it is considered that the charge of activated charcoal should be replaced, it is sufficient to unclip one of the end plates from the body 1 and to remove the corresponding foil. The receptacle is then emptied and refilled with the requisite amount of a fresh charge, before replacing the foil and clipping the end plate back on to the body. If necessary this opportunity is taken to replace the "Reemay" R type foil element which is held between the end plate and the end of the body.

It goes without saying that if the receptacle R is not re-used as an air treatment device it can find very numerous other uses after having been emptied and cleaned. By using appropriate end plates and removing one or other of the foils as necessary, the device can be used as a salt cellar, a pepper pot, a toy cup, a detergent dosimeter, or a pot for various uses. This may promote great interest in the device and make it a very commercial proposition.

Claims

1. An air treatment device comprising a hollow body containing a charge of a substance for effecting the desired treatment of the air, the body having a pair of openings at opposite ends thereof, each of which is closed by an air permeable foil held across the opening by an end plate which is attached to the body and which is provided with apertures for the passage of air into and out of the body, the charge occupying only a portion of the internal volume of the body so as to facilitate the shaking of the charge and the renewal of the contact surface between the air and the charge.

2. A device according to claim 1, in which the amount of the treatment charge contained in the body is such that the centre of gravity of the device is below its horizontal median plane when the device is on a horizontal surface, thus affording a stable position of equilibrium.

3. A device according to claim 2, in which the treatment charge fills the body substantially to the level of the horizontal median plane.

4. A device according to any one of the preceding claims, in which the end plates are clipped on to the body so that they can be removed when desired.

5. A device according to any one of claims 1 to 3, in which the end plates are screwed on to the body so that they can be removed when desired.

6. A device according to any one of the preceding claims, in which each foil is disposed in a removable manner in the corresponding end plate, the periphery of the foil being located in a groove in the end plate.

7. A device according to any one of claims 1 to 5, in which the foils are stuck to the end plates.

8. A device according to any one of claims 1 to 5, in which the foils are stuck to the ends of the body.

9. A device according to any one of the preceding claims, in which the charge is a polyvalent substance, such as activated charcoal, for absorbing odours whereby the device performs a deodorising function.

10. A device according to claim 1, substantially as described with reference to the accompanying drawings.