AU2003229992B2

AU2003229992B2 - Dehumidifying device

Info

Publication number: AU2003229992B2
Application number: AU2003229992A
Authority: AU
Inventors: David Bedford; Richard Peter Harbutt
Original assignee: Reckitt Benckiser UK Ltd
Current assignee: Reckitt Benckiser UK Ltd
Priority date: 2002-05-04
Filing date: 2003-05-02
Publication date: 2009-01-08
Anticipated expiration: 2023-05-02
Also published as: WO2003092866A1; MXPA04010897A; KR100938360B1; AU2003229992A1; ZA200409678B; GB0210315D0; KR20050008704A; BR0309584A

Description

WO 03/092866 PCT/GB03/01944 1 DEHUMIDIFYING DEVICE The present invention relates to a device for absorbing water vapour. Particularly, although not exclusively, it relates to a device for dehumidifying air in a confined or limited space; and to associated methods.

Humidity, or water vapour in air, is often undesirable as it may interfere with the storage of moisture sensitive materials, such as foodstuffs, cosmetics, pharmaceuticals, household goods and clothes, or it may adversely effect the operation of moisture sensitive equipment. This problem may be particularly pronounced in those areas where humidity levels are particularly high, such as those countries having hot humid climates.

It is therefore often desirable to dehumidify air.

Traditional methods for dehumidifying air include the use of mechanical refrigeration equipment and water absorbent materials, such as silica gel.

Typically, methods employing refrigeration equipment involve cooling air to a predetermined temperature below its dew point, so that water condenses from the air and the water may be drained away. Thereafter, the air may be reheated to a predetermined warmer temperature. Techniques including absorbent materials may include continuous operation systems so that water is absorbed by the absorbent in a first cycle and then water desorbed from the absorbent by the application of heat in a second cycle.

WO 03/092866 PCT/GB03/01944 2 Suitably, these techniques suffer from various disadvantages as they typically require bulky and heavy equipment, such as compressors, fans and heaters, which are interconnected by a network of pipes so that water vapour is absorbed continuously from air. Typically, such systems are ill-suited for operation in a confined or limited space. Moreover, the cost associated with such systems may prohibit their use in a domestic environment.

In an attempt to overcome the disadvantages associated with using the aforementioned systems in a confined or limited space, alternative techniques have been developed that include exposing air to an absorbent material. In particular, portable smaller devices comprising a container housing an absorbent material have been employed for dehumidifying air in a limited or confined space, particularly in a domestic environment.

Although absorbents such as silica gel may be employed in these devices, typically silica gel only absorbs up to its weight of water and it is necessary to employ an absorbent having a higher capacity for water vapour absorption to prolong the life and improve the efficiency of the device. Suitably, dessicants, such as calcium chloride, which may absorb 4 to 5 times its weight of water, have been employed in such devices. On absorption of water vapour the dessicant forms a liquid or gel, and is such that liquid seeps from it.

Although devices including a dessicant have gone some way to solving the problems associated with absorbing water vapour in a confined space, particularly in a domestic environment, a major drawback associated with WO 03/092866 PCT/GB03/01944 3 these devices is they usually only function satisfactorily, or function most efficiently, when they are orientated in a single normal operating position.

For example, a device which is designed to be positioned horizontally with respect to a level surface does not usually operate satisfactorily or efficiently if it is tilted, particularly placed vertically, with respect to a horizontal surface. Whereas, a device which is designed to be positioned vertically with respect to a horizontal surface does not usually operate satisfactorily if it is positioned horizontally with respect to a level surface.

Suitably, when such a device is moved from its single normal operating position the drainage of liquid from the deliquescent agent may be impaired. Moreover, liquid that has previously drained from the deliquescent agent while the device is in its single normal operating position may subsequently contact the dessicant when the device is moved. Consequently, the absorptive capacity of the dessicant may be significantly reduced if such a device is not orientated in its single normal operating position.

Suitably, the utility of a dehumidifying device which functions most efficiently in a single operating position may be significantly reduced, as it may be necessary to use a different type of device each time the device has to be orientated differently. This is not only inconvenient for the user but also typically results in increased unnecessary expenditure.

00 4 oO C The present invention desirably seeks to solve the 3 aforementioned problems associated with absorption of water vapour employing a desiccant, in particular, 1 absorption of water vapour from air in a confined space, particularly in a domestic environment.

h Any discussion of documents, acts, materials, c-I devices, articles or the like which has been included in the present specification is solely for the purpose of 10 providing a context for the present invention. It is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

According to a first aspect, the present invention provides a dehumidifying device for absorbing water vapour from ambient air, the device comprising a container having an opening to permit water vapour to enter the container, wherein the container comprises a desiccant reservoir having a desiccant therein and a liquid collection cavity that is laterally displaced from and in fluid communication with the desiccant reservoir, the device when either positioned in a first operating position in which the device is oriented in a substantially horizontal plane, or a second operating position in which the device is not oriented in a substantially horizontal plane, permitting liquid to pass from the desiccant reservoir to the liquid collection cavity.

00 4A

<DA

c- Throughout this specification the word "comprise", or O variations such as "comprises" or "comprising", will be Sunderstood to imply the inclusion of a stated element, cI integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

C- Suitably, the desiccant reservoir may permit drainage O of liquid from the desiccant not only when the C- 10 dehumidifying device is placed on a horizontal surface but also when the dehumidifying device is not orientated horizontally, for example it is upstanding, with respect to a level surface. Conveniently, the dehumidifying device may function satisfactorily when it is orientated in more than one operating position and when it is moved from one WO 03/092866 PCT/GB03/01944 operating position to another operating position.

Consequently, the utility of the device may be significantly improved compared with a device which only functions satisfactorily, or most efficiently, when it is orientated in a single normal operating position, as the dehumidifying device of the present invention typically negates the need for using a different device each time it has to be orientated differently.

In "a first operating position, in a substantially horizontal plane" the device is typically located on a level surface, for example a shelf, drawer bottom or table top.

In "a second operating position, not in a substantially horizontal plane" we mean when the device is tilted or, especially, upstanding. Suitably, we may regard the device as not being orientated in a substantially horizontal plane when the device is placed on a nonhorizontal surface, when the device is tilted or upstanding from a horizontal surface, and when the device is hung such that the device is in a substantially vertical plane.

Suitably, we regard the dehumidifying device as not being orientated in a substantially horizontal plane when the device is tilted or upstanding from a level surface, or suspended, such that the device, particularly the membrane covering the desiccant reservoir and liquid collection cavity as described hereinafter, forms an angle of inclination of greater than or equal to 10', preferably greater than or equal to 150, more preferably greater than or equal to 20', even more preferably greater than or WO 03/092866 PCT/GB03/01944 6 equal to 40°, even more preferably greater than or equal to 60°, most preferably greater than or equal to 75' with respect to a level surface.

Suitably, we regard the dehumidifying device as not being orientated in a substantially horizontal plane when the device is tilted or upstanding from a level surface, or suspended, such that the device, particularly the membrane covering the desiccant reservoir and liquid collection cavity as described hereinafter, forms an angle of inclination of less than or equal to 170°, preferably less than or equal to 175°, more preferably less than or equal to 160°, even more preferably less than or equal to 150°, even more preferably less than or equal to 135°, even more preferably less than or equal to 120°, most preferably less than or equal to 105" with respect to a level surface.

Especially, we regard the dehumidifying device as not being orientated horizontally with respect to a level surface when the device is substantially perpendicularly disposed with respect to the level surface. For example, the dehumidifying device is suspended or upstanding from a level surface such that the device, particularly the membrane covering the desiccant reservoir and liquid collection cavity as described hereinafter, is in a substantially vertical plane i.e. approximately 90° to a level surface.

Preferably, the desiccant reservoir is adapted to permit liquid to pass from the desiccant reservoir to the liquid collection cavity when the dehumidifying device is positioned in all positions as mentioned herein.

WO 03/092866 PCT/GB03/01944 7 Preferably, the desiccant reservoir includes a first inner surface that slopes downwardly towards the liquid collection cavity when the dehumidifying device is placed in the first operating position e.g. the device is placed on a level surface. More preferably, the first inner surface defines the base of the desiccant reservoir.

Conveniently, such a surface may permit increased drainage of liquid from the deliquescent agent when the device is placed on a horizontal surface.

Preferably, the desiccant reservoir includes a second inner surface that slopes downwardly towards the liquid collection cavity when the dehumidifying device is placed in the second operating position e.g. the device is suspended or upstanding with respect to a level surface.

More preferably, the second inner surface defines a side wall of the desiccant reservoir.

Conveniently, the second inner surface may permit increased drainage of liquid from the deliquescent agent when the device is suspended or upstanding with respect to a horizontal surface.

Most preferably, the desiccant reservoir includes a first inner surface that slopes downwardly towards the liquid collection cavity when the dehumidifying device is placed in the first operating position and a second inner surface that slopes downwardly towards the liquid collection cavity when the device is placed in the second operating position.

WO 03/092866 PCT/GB03/01944 8 Preferably, the liquid collection cavity includes a first inner surface that slopes downwardly and away from the desiccant reservoir when the dehumidifying device is placed in the first operating position e.g. the device is placed on a level surface. More preferably, the first inner surface defines the base of the liquid collection cavity. Conveniently, the inclusion of such a first inner surface may restrict liquid in the liquid collection cavity from passing to the desiccant reservoir when the device is moved between different operating positions.

Furthermore, the first inner surface may permit increased drainage of liquid away from the desiccant reservoir into the base of the collection region when the device is placed in different operating positions.

Preferably, the liquid collection cavity includes a second inner surface that slopes downwardly and away from the desiccant reservoir when the dehumidifying device is placed in the second operating position e.g. the device is suspended or upstanding with respect to a level surface.

More preferably, the second inner surface defines a side wall of the liquid collection cavity. Conveniently, the inclusion of such a second inner surface may restrict liquid in the liquid collection cavity from passing to the desiccant reservoir when the device is moved between different operating positions. Furthermore, the second inner surface may permit increased drainage of liquid away from the desiccant reservoir into the base of the collection region when the device is placed in different operating positions.

Most preferably, the liquid collection cavity includes a first inner surface that slopes downwardly and away from WO 03/092866 PCT/GB03/01944 9 the desiccant reservoir when the dehumidifying device is placed in the first operating position and a second inner surface that slopes downwardly and away from the desiccant reservoir when the device is placed in the second operating position.

Suitably, the liquid collection cavity is separate from and in fluid communication with the desiccant reservoir. Preferably, the desiccant reservoir is vertically displaced with respect to the liquid collection cavity when the dehumidifying device is positioned in the first operating position. Most preferably, the desiccant reservoir is displaced above the liquid collection cavity when the dehumidifying device is positioned in the first operating position.

Preferably, the dehumidifying device includes one or more passageways between the liquid collection region and the desiccant reservoir to permit liquid to pass from the desiccant reservoir to the liquid collection cavity.

Preferably, the dehumidifying device includes a flowthrough means to permit liquid to pass from the desiccant reservoir to the liquid collection cavity and to prevent the deliquescent agent from passing from the desiccant reservoir to the liquid collection cavity when the device is orientated in any position as described herein.

Suitably, the flow-through means is perforate and includes holes or pores which are dimensioned to permit liquid to pass therethrough and prevent the deliquescent agent from passing therethrough. Typically, the openings in the flow-through means have a minimum width of 0.1 to WO 03/092866 PCT/GB03/01944 2mm. Examples of suitable flow-through means include an open-cell sponge or a web such as an open weave membrane formed from plastic materials, such as polyolefins and polyamides. Preferably, one or more passageways, most preferably each of the passageways, between the liquid collection cavity and the desiccant reservoir include a flow-through means as defined herein.

According to a preferred embodiment of the present invention, the desiccant reservoir is surrounded by the liquid collection cavity.

In accordance with a further preferred embodiment of the present invention the dehumidifying device includes a first liquid collection cavity and a second separate liquid collection cavity. Suitably, the first and second liquid collection cavities are in fluid communication, preferably by one or more passageways as described herein, with the desiccant reservoir.

When the dehumidifying device includes said first and second separate liquid collection cavities, the desiccant reservoir may be adapted to permit liquid to pass from the desiccant reservoir to the first liquid collection cavity only, to the second separate liquid collection cavity only, or to both the first and second liquid collection cavities simultaneously when the device is placed in the first operating position.

Preferably, the desiccant reservoir is adapted to permit liquid to pass from the desiccant reservoir to both of the first and second liquid collection cavities simultaneously when the dehumidifying device is placed in WO 03/092866 PCT/GB03/01944 11 the first operating position e.g. placed on a level surface.

Suitably, the desiccant reservoir may include a first inner surface that slopes downwardly and towards the first liquid collection cavity only, the second liquid collection cavity only, or both the first and second liquid collection cavities when the device is placed in the first operating position e.g. placed on a level surface. Preferably, said first inner surface defines the base of the desiccant reservoir.

Preferably, the desiccant reservoir includes a first inner surface that slopes downwardly and towards both the first and second liquid collection cavities when the device is placed on a level surface. For example, the base of the desiccant reservoir may be bowed or dome-shaped.

When the dehumidifying device includes said first and second liquid collection cavities, the desiccant reservoir may be adapted to permit liquid to pass from the desiccant reservoir to the first liquid collection cavity only, to the second separate liquid collection cavity only, or to both the first and second liquid collection cavities simultaneously when the dehumidifying device is positioned in the second operating position e.g. suspended or upstanding with respect to a level surface.

Suitably, the desiccant reservoir may include a second inner surface that slopes downwardly and towards the first liquid collection cavity only, the second liquid collection cavity only, or both the first and second liquid collection cavities when the device is positioned WO 03/092866 PCT/GB03/01944 12 in the second operating position. Preferably, said second inner surface defines a side wall of the desiccant reservoir.

Preferably, the desiccant reservoir is adapted to permit liquid to pass selectively from the desiccant reservoir into either the first or second separate liquid collection cavities when the device is positioned in the second operating position.

A particularly preferred dehumidifying device having first and second separate liquid collection cavities comprises first and second separate liquid cavities laterally and vertically displaced with respect to the desiccant reservoir when the device is positioned in the first operating position. More preferably, both the first and second cavities are displaced laterally from and below the desiccant reservoir when the device is positioned in the first operating position. Preferably, the first liquid collection cavity is substantially opposite to the second liquid collection cavity.

Suitably, the second liquid collection cavity may independently include any feature of the first liquid collection cavity as described herein.

Preferably, the dehumidifying device includes a foot to permit the device to upstand with respect to a level surface. Preferably, the foot permits the device to be stood on a level surface such that the liquid collection cavity is below the desiccant reservoir. Preferably, the foot permits the device to be stood on a level surface such that the device, particularly the membrane covering WO 03/092866 PCT/GB03/01944 13 the desiccant reservoir and liquid collection cavity or cavities as defined hereinafter, is in a substantially vertical plane. More preferably, the foot forms a part of the liquid collection cavity(ies) Alternatively, or additionally, the device includes a formation to permit the device to be suspended, preferably from one end of the device, above a level surface such that the liquid collection cavity is below the desiccant reservoir. Preferably, the formation permits the device to be suspended such that the device, particularly the membrane covering the desiccant reservoir and liquid collection cavity as defined hereinafter, is in a substantially vertical plane. The formation may, for example, be an aperture to receive a wall hook.

Alternatively, and preferably, it may itself be a hook formation. Preferably, the formation forms a part of the desiccant reservoir.

In a preferred embodiment, the device includes a formation as described above that is moveable about a fold line. Conveniently, the formation may permit the device to be suspended and when the formation is folded about the fold line it may act as a stand as described above to permit the device to be positioned in a first operating position in a substantially horizontal plane.

Preferably, the dessicant absorbs at least its own weight of water, at 250C. Preferably, the deliquescent agent forms a liquid or gel on absorption of water vapour, such that liquid may drain from it.

WO 03/092866 PCT/GB03/01944 14 Preferred dessicants comprise calcium chloride and/or magnesium chloride as these exhibit an acceptable water absorption capacity. This does not exclude other deliquescent salts, for example when intended for use in other environments, for example industrial environments.

One preferred dessicant is calcium chloride alone.

Another is magnesium chloride. Especially preferred is calcium chloride providing up to 20 wt% of the total content and the balance comprising a different waterabsorbing agent, preferably magnesium chloride.

Suitably, the dessicant as defined above may include other components selected from a binder or thickener, for example starch, a pest control agent, a perfume, and odour absorbing agent (for example a zeolite), an antimicrobial agent, and combinations thereof. Preferably, an antimicrobial agent is included to prevent microbe formation in liquid formed by dissolution of the deliquescent agent.

Preferably, the dessicant is in the form of granules and/or a powder disposed in the desiccant reservoir.

Preferably, the desiccant reservoir is covered with a vapour-permeable liquid-impermeable membrane to permit water vapour to enter the container and prevent liquid from exiting the container.

Unexpectedly, we have found that the rate of absorption of water vapour by the dessicant may be increased when the dessicant is in contact with the vapour-permeable liquid-impermeable membrane. Thus, WO 03/092866 PCT/GB03/01944 according to a preferred embodiment of the present invention, the dessicant contacts the vapour-permeable liquid-impermeable membrane.

Preferably, the liquid collection cavity(ies) is covered with a liquid-impermeable membrane to act as a barrier to vapour and liquid. Thus it may be, for example, a metal foil or vapour- and liquid-impermeable plastics film. However, the vapour-permeable liquid-impermeable membrane which closes the desiccant reservoir is, as stated, liquid-impermeable and may be used to close the liquid collection cavity(ies) as well. It will be appreciated that although a vapour-permeable liquidimpermeable membrane may be relatively expensive there are likely to be manufacturing complications in applying one type of membrane over the desiccant reservoir and another type of membrane over the liquid collection cavity(ies).

Manufacturing is eased by using a single membrane to cover both the desiccant reservoir and liquid collection cavity(ies), and such embodiments are preferred.

Preferably the membrane, or membranes, are secured in place by adhesive or heat sealing. Heat sealing is preferred. The dehumidifying device is preferably formed with a rim or flange around its periphery to provide a flat band against which the membrane(s) may engage.

Suitable vapour-permeable liquid-impermeable membranes are well known to those skilled in the art, such as polytetrafluoroethylene (PTFE) membranes available from W L Gore and Associates Inc., or polyolefin films available under the trade mark TYVEK, or polyurethane films.

WO 03/092866 PCT/GB03/01944 16 Preferably, a membrane used in the present invention is of a type which provides moisture transmission of at least 1000 g, preferably at least 5000 g, and most preferably at least 10000 g water/m 2 through the membrane/day.

Suitably, the inlet of the container includes a removable fluid tight seal so that it may be stored without degradation of dessicant. Suitably, the fluid tight seal extends across the desiccant reservoir.

Preferably, the fluid type seal extends across both the desiccant reservoir and the liquid collection cavity(ies).

Suitably, the dehumidifying device of the present invention is dimensioned so that it may be used in a confined space, particularly a confined space in a domestic environment, such as a drawer, chest, wardrobe, cupboard, packing case, refrigerator, freezer, cool box, caravan, car, car boot or boat. Suitably, the dehumidifying device of the present invention is 5 to cm high, 10 to 50 cm long, and 5 to 30 cm wide.

Typically, the device includes 50-1000 g of waterabsorbing agent, preferably 100-500 g.

Suitably, the container is rigid or flexible. Most preferably, the container is rigid.

Preferably, the container comprising the desiccant reservoir and liquid collection cavity(ies) is formed from a plastics material, for example a polyolefin, by techniques well known to those skilled in the art such as injection moulding, blow moulding and vacuum forming.

WO 03/092866 PCT/GB03/01944 17 According to a further aspect, the present invention provides a method for removing water vapour from a locus, preferably an enclosed locus, comprising locating a dehumidifying device as described herein in the locus.

The present invention will now be illustrated by way of the following non-limiting examples, in which: Figure 1 is a front view of a first embodiment of the dehumidifying device of the present invention, orientated in a second operating position such that the device is in a substantially vertical plane; Figure 2 is a side-sectional view of the device of Figure 1, orientated in a first operating position such that the device is substantially horizontally disposed with respect to a level surface; Figure 3 is a side-sectional view of the device of Figure 1, orientated in the second operating position such that the device is upstanding in a substantially vertical plane; Figure 4 is a top-plan view of a second embodiment of the dehumidifying device of the present invention, orientated in a first operating position such that the device is substantially horizontally disposed with respect to a level surface; Figure 5 is a perspective view of the device of Figure 4 orientated in the first operating position; WO 03/092866 PCT/GB03/01944 18 Figure 6 is a perspective view of a third embodiment of the dehumidifying device of the present invention orientated in a first operating position such that the device is substantially horizontally disposed with respect to a level surface; and Figure 7 is a side-sectional view of the device of Figure 7 orientated in the first operating position.

The dehumidifying device 1 as shown in Figures 1 to 3 comprises a container 2 that is formed by injection moulding a thermoplastics material. The container 2 comprises an integral desiccant reservoir 3 in fluid communication with a liquid collection cavity 4 via passageway 6. The passageway 6 includes an open-cell sponge 8 to permit liquid to pass from the desiccant reservoir 3 to the liquid collection cavity 4 and to prevent deliquescent agent 10 (not shown in Figure 1) in the desiccant reservoir 3 from passing to the liquid collection cavity 4.

As is best shown in Figure i, the device 1 is generally arch-shaped in frontal appearance. The desiccant reservoir 3 is generally oval-shaped in frontal appearance and the liquid collection cavity 4 is generally archshaped in frontal appearance.

The desiccant reservoir 3 includes a side wall 12 that defines an inner surface which slopes downwardly and towards passageway 6, and consequently towards the liquid collection cavity 4, when the device is in the second operating position as shown in Figures 1 and 3. The liquid collection cavity 4 includes a side wall 14 that defines WO 03/092866 PCT/GB03/01944 19 an inner surface which slopes downwardly and away from passageway 6, and consequently away from the desiccant reservoir 3, when the device is in the second operating position as shown in Figures 1 and 3. As shown in Figures 1 and 3, the liquid collection cavity 4 is below the desiccant reservoir when the device is in the second operating position.

As is more clearly shown in Figure 2, the desiccant reservoir 3 is laterally disposed from and above the liquid collection cavity 4 when the device is positioned in the first operating position e.g. generally horizontally with respect to a level surface. The base 16 of the desiccant reservoir 3 defines an inner surface which slopes downwardly and towards passageway 6, and subsequently downwardly and towards liquid collection cavity 4, when the device is positioned in the first operating position. The base 18 of the liquid collection cavity 4 defines an inner surface which slopes downwardly and away from passageway 6, and subsequently downwardly and away from desiccant reservoir 3, when the device is positioned in the first operating position.

The base 18 of the liquid collection cavity 4 includes an integral foot 20 extending downwardly therefrom, so that the device 1 may be stood substantially perpendicular to a level surface in the second operating position as shown in Figure 3. The base 16 of the desiccant reservoir 3 includes an integral stand 22 extending downwardly therefrom such that its lower end is level with the lower end of foot 20, so that the device may be placed substantially horizontal to a level surface i.e. in the first operating position as shown in Figure 2.

WO 03/092866 PCT/GB03/01944 The device has a rim 24 extending all around its periphery. At its upper end the rim 24 includes an aperture 26, for hanging.

A single vapour-permeable liquid-impermeable membrane 27 (not shown in Figures 1 to 3) comprising a TYVEK material (Trade Mark; HDPE material from DuPont) is heatsealed to the whole of rim 24, so as to close the desiccant reservoir 3, liquid collection cavity. 4 and the passageway 6 therebetween.

The desiccant reservoir 3 is filled with calcium chloride, as deliquescent agent The operation of the device 1 shown in Figures 1 to 3 is simple. After purchase the user removes an impermeable plastics cover (not shown). This is provided during manufacture in order to maintain the calcium chloride material in a substantially desiccated condition, prior to the commencement of use. The desiccant reservoir 3, liquid collection cavity 4 and passageway 6 therebetween, remain covered by the vapour-permeable liquid-impermeable membrane 27. Conveniently, the device may function satisfactorily and efficiently when it is orientated in more than one operating position and when it is moved from one operating position to another operating position.

As shown in Figure 2, when the device is placed in the first operating position such that the device is placed on a level surface i.e. the membrane 27 is substantially horizontal to a level surface, water vapour passes through membrane 27 and is absorbed by the dessicant 10 in the WO 03/092866 PCT/GB03/01944 21 desiccant reservoir 3. After substantial absorption of water vapour, liquid 28 is given up by the dessicant The liquid 28 drains away from the dessicant along the downwardly sloping inner surface of the desiccant reservoir 3, through passageway 6 and sponge 8, and into the liquid collection cavity 4. Thus liquid 28 collects in the liquid collection cavity 4, in particular the liquid collection cavity 4 in the region of foot 20 due to the downwardly sloping inner surface of the liquid collection cavity 4.

When the device (is placed in the second operating position such that the device is stood substantially vertically on a level surface (Figure 3) or hung in place so that the device is substantially vertically disposed with respect to a level surface the membrane 27 is in a generally vertical plane in both cases), with the liquid collection cavity 4 lowermost, liquid 28 drains away from the dessicant along the downwardly sloping side wall 12 of the desiccant reservoir 3, through passageway 6 and sponge 8, and into the liquid collection cavity 4.

Thus liquid collects in the liquid collection cavity 4 in the region of foot 20 i.e. away from the desiccant reservoir 3.

If the device 1 is moved from the first operating position as shown in Figure 2 to the second operating position as shown in Figures 1 and 3 or an intermediate position therebetween, and vice-versa, then the downwardly sloping inner surface of the base 18 of liquid collection cavity 4 restricts liquid 28 in the liquid collection cavity 4 from passing to the desiccant reservoir 3.

WO 03/092866 PCT/GB03/01944 22 Conveniently, the device may function satisfactorily and efficiently when it is orientated in more than one operating position and when it is moved from one operating position to another operating position.

Conveniently, the sponge 8 prevents the calcium chloride deliquescent agent from falling into the liquid collection cavity 4 when the device is not placed in the first operating position and when the device is moved between different operating positions, even at the commencement of use when the deliquescent agent 10 is dry.

There is shown in Figures 4 and 5 an alternative embodiment of the dehumidifying device of the present invention and corresponding features are indicated with identical reference numerals. As shown in Figure 4 the device is generally oval-shaped in frontal appearance and comprises an integral oval-shaped desiccant reservoir 3 surrounded by an oval-shaped liquid collection cavity 4.

The liquid collection cavity 4 is laterally displaced from and below the desiccant reservoir when the device is placed on a level surface. The desiccant reservoir 3 includes a number of passageways 6 each having a sponge therein (not shown) to permit liquid to pass from the desiccant reservoir 3 to the liquid collection cavity 4 and to prevent deliquescent agent 10 in the desiccant reservoir 3 from passing into the liquid collection cavity 4.

Although not shown, it will be appreciated from Figure 4 that the desiccant reservoir 3 includes an oval-shaped side wall 12 that defines inner surfaces which slope downwardly and towards passageways 6, and consequently WO 03/092866 PCT/GB03/01944 23 towards the liquid collection cavity 4, when the device 1 is positioned in a non-horizontal plane i.e. the membrane 26 is in a non-horizontal orientation with respect to a level surface and the device is in a second operating position.

The oval-shaped side wall 12 of the desiccant reservoir 3 defines outer surfaces which slope downwardly and towards the liquid collection cavity 4. The outer surface of the oval-shaped side wall aids drainage of liquid from the desiccant reservoir 3 to the liquid collection cavity 4 when the device is positioned in various operating positions.

Although not shown, the base 16 of the desiccant reservoir 3 has a dome-shaped inner surface which slopes downwardly and away from the centre of the desiccant reservoir 3 to each of the passageways 6. Such a domeshaped base 12 permits drainage of liquid 28 from the desiccant reservoir 3 to at least one of passageways 6, and hence to liquid collection cavity 4, when the device is positioned in various operating positions.

There is shown in Figures 6 and 7 a further alternative embodiment of the dehumidifying device of the present invention and corresponding features are indicated with identical reference numerals. As shown in Figure 7 the device is generally oval-shaped in plan view and comprises an integral oval-shaped desiccant reservoir 3 in fluid communication with generally arch-shaped first 4 and second 4' liquid collection cavities via passageways 6, Each of first 4 and second 4' liquid collection cavities are displaced laterally and below the desiccant WO 03/092866 PCT/GB03/01944 24 reservoir 3 when the device is placed on a level surface.

Passageways 6, 6' include a sponge (not shown) to permit liquid to pass from the desiccant reservoir 3 to the liquid collection cavities 4, 4' and to prevent deliquescent agent 10 in the desiccant reservoir 3 from passing to the liquid collection cavities 4, 4'.

Although not shown, it will be appreciated from Figure 6, the desiccant reservoir 3 includes a generally ovalshaped side wall 12 that defines inner surfaces which slope downwardly towards passageways 6 or passageway 6', and consequently towards the liquid collection cavities 4 and 4' respectively, when the device is positioned in a generally non-horizontal plane i.e. the membrane is not substantially horizontal with respect to a level surface and the device is in a second operating position.

As is more clearly shown in Figure 7, the device 1 is bow-shaped. Conveniently, the base of the desiccant reservoir defines an inner surface which slopes downwardly and towards both the passageways 6, and consequently towards both liquid collection cavities 4, when the device is placed in a first operating position such that the device is positioned on a generally level surface i.e.

the membrane is substantially horizontally disposed with respect to a level surface. The base 18, 18' of each liquid collection cavity 4, 4' defines a surface which slopes downwardly and away from desiccant reservoir 3, when the device is positioned generally in a first operating position such that the device is positioned on a level surface.

WO 03/092866 PCT/GB03/01944 In use, the device may be positioned on a level surface, so that liquid 28 formed by dissolution of the deliquescent agent drains from the desiccant reservoir 3 into each liquid collection cavity 4, Alternatively, the device may be placed on a non-level surface, so that liquid 28 formed by dissolution of the deliquescent agent drains from the desiccant reservoir 3 into liquid collection cavity 4 or liquid collection cavity 4'.

Claims

2. A dehumidifying device as claimed in claim 1 wherein the base of the desiccant reservoir defines a first inner surface that slopes downwardly and towards the liquid collection cavity when the device is positioned in the first operating position.
3. A dehumidifying device as claimed in claim 1 or claim 2 wherein the base of the liquid collection cavity defines a first inner surface that slopes downwardly and away from the desiccant reservoir when the device is positioned in the first operating position. 00 27 c O
4. A dehumidifying device as claimed in any one of the 0 preceding claims wherein the device includes one or C-i more passageways between the liquid collection 5 cavity and the desiccant reservoir to permit liquid c-i to pass from the desiccant reservoir to the liquid collection cavity. c, c-i A dehumidifying device as claimed in any one of the preceding claims further including flow-through means to permit liquid to pass from the desiccant reservoir to the liquid collection cavity and to prevent the desiccant in the desiccant reservoir from passing to the liquid collection cavity.
6. A dehumidifying device as claimed in any one of the preceding claims wherein the desiccant reservoir is laterally circumscribed by the liquid collection cavity.
7. A dehumidifying device as claimed in any one of claims 1 to 5 further including a second separate liquid collection cavity.
8. A dehumidifying device as claimed in claim 7 wherein the second liquid collection cavity is laterally displaced from the desiccant reservoir when the device is positioned in the first operating position.
9. A dehumidifying device as claimed in claim 7 or wherein the second liquid collection cavity is 00 28 O O substantially opposite said first liquid collection cavity. 0 c- 10. A dehumidifying device as claimed in any one of the preceding claims wherein the desiccant reservoir is covered with a vapour-permeable liquid-impermeable C membrane. M
11. A dehumidifying device as claimed in any one of the O 1 preceding claims wherein the device is positioned in the second operating position in an upright plane.
12. A dehumidifying device as claimed in any one of the preceding claims wherein a side wall of the desiccant reservoir defines a second inner surface that slopes downwardly and towards the liquid collection cavity when the device is positioned in the second operating position.
13. A dehumidifying device as claimed in any one of the preceding claims wherein a side wall of the liquid collection cavity defines a second inner surface that slopes downwardly and away from the desiccant reservoir when the device is positioned in the second operating position.
14. A method of absorbing water vapour from a locus, preferably an enclosed locus, comprising locating a dehumidifying device as defined in any one of the preceding claims in the locus. 17/12 2008 WED 16:40 FAX +61 2 8231 1099 FBRice Co 1002/002 00 29 O O
15. A dehumidifying device as described herein with reference to the description and accompanying drawings.
16. A method of absorbing water vapour substantially as described herein c with reference to the description and accompanying drawings. Ca 0 O C COMS ID No: ARCS-217473 Received by IP Australia: Time 16:40 Date 2008-12-17