AU733265B2

AU733265B2 - A hand dryer and a method of disinfecting and deodorising the dryer and air emitted from it

Info

Publication number: AU733265B2
Application number: AU77349/98A
Authority: AU
Inventors: Roger Basil Lawson Scheepers
Original assignee: CASTLEGATE TRADING Ltd
Current assignee: CASTLEGATE TRADING Ltd
Priority date: 1996-12-17
Filing date: 1997-12-15
Publication date: 2001-05-10
Anticipated expiration: 2017-12-15
Also published as: NZ331469A; WO1998026703A1; ZA9610586B; AU7734998A

Description

WO 98/26703 PCT/GB97/03343 1 A HAND DRYER AND A METHOD OF DISINFECTING AND DEODORISING THE DRYER AND AIR EMITTED FROM IT BACKGROUND OF THE INVENTION THIS invention relates to a hand dryer and a method of disinfecting and deodorising the dryer and air emitted from it.

Electrically operated hot air hand dryers are convenient to use in washrooms because, unlike towel dispensers, they do not require continual recharging.

Thus, the servicing required is reduced. However, it is increasingly thought that they may be unhygienic as they provide an ideal warm wet environment for the growth of bacteria and other disease-causing pathogens.

SUBSTITUTE SHEET (RULE 26) Summary of the Invention According to one aspect, the invention provides a method of disinfecting a hand dryer, and a stream of air emitted from the hand dryer comprising dispensing vaporised disinfectant into or in proximity to the dryer so that the disinfectant circulates in an area in proximity to and within the dryer and is entrained in the stream of air emitted from the dryer, the disinfectant including triethylene glycol.

Preferably, the method also comprises the step of deodorising the hand dryer and the stream of air emitted from the hand dryer by dispensing vaporised deodorant into or in proximity to the dryer so that the deodorant circulates in an area in proximity to and within the dryer and is entrained in the stream of air emitted from the dryer.

The disinfectant and/or deodorant is preferably in the form of a vaporisable liquid contained within a carrier.

15 The vaporisable liquid preferably contains each of the deodorant and disinfectant.

The carrier is preferably located within the dryer.

More preferably, the carrier is attached to an inner surface or sidewall of the dryer or dryer housing and out of a direct air stream.

According to another aspect, the invention provides A hand dryer comprising a housing and a liquid or solid carrier impregnated with a disinfectant including triethylene glycol positioned in or on the housing for disinfecting the dryer and a stream of air emitted from the dryer.

Preferably the carrier is also impregnated with a liquid or solid 25 deodorant. The disinfectant and/or deodorant may be in the form of a vaporisable liquid. The vaporisable liquid may comprise each of the disinfectant and the deodorant.

WO 98/26703 PCT/GB97/03343 3 The housing may comprise a base and a cover.

The base may define an air inlet and the cover may define an air outlet and a carrier may be positioned on each of two opposed side walls of the cover and out of a direct air stream.

The cover may define an air inlet and an air outlet and the carrier may be positioned on the base and out of a direct air stream.

The carrier may be a fibrous material or a plastics material impregnated with the deodorant and/or disinfectant and/or fragrance. If it is a fibrous material, it is preferably contained within a sleeve which transmits the deodorant and/or disinfectant and/or fragrance in the carrier to the atmosphere.

The carrier may be retained within a carrier retainer.

If the housing is moulded from a plastics material, the carrier retainer may be moulded integrally with the housing.

The carrier retainer may comprise a base and a cover slideably received :within the base.

The cover preferably has an exposed surface and a number of apertures defined in its exposed surface to allow a passage of air into the cover and over the carrier to facilitate the vaporisation of the liquid or solid deodorant and/or disinfectant and/or fragrance within the carrier.

The apertures near one side of the cover are preferably larger than the other apertures.

The carrier retainer may be angled in such a way in position in or on the housing that the larger apertures are in a lower position to allow a greater passage of air over the carrier in this region where the deodorant and/or disinfectant and/or fragrance tends to accumulate. Alternatively, the cover of the carrier retainer may be rotated through 1800 so that the larger apertures are in an upper position to restrict the passage of air over the carrier in this region and thus to restrict evaporation from the carrier.

The sleeve may be made of a plastics material, more preferably polyethylene.

The rate of transmission of the deodorant and/or disinfectant and/or fragrance may be controlled by varying the thickness of the plastics material.

The carrier may comprises a particulate material contained within an elongate envelope made of a flexible porous material.

The elongate envelope preferably has attachment means associated 15 with one end thereof.

The attachment means preferably comprises an eyelet defined in the envelope within which a hook can be received.

The particulate material may be a cellulosic material, such as wood shavings or sawdust, or a powder or vermiculite.

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i ooee WO 98/26703 PCT/GB97/03343 The envelope preferably comprises a non-woven plastics material or a nonwoven fibrous cellulosic material which may be viscose or rayon or a mixture thereof or polypropylene.

The envelope is preferably dimensioned to prevent the particulate material from collecting at the base thereof. The dimensions of the envelope will vary according to the particulate material it is filled with.

The carrier retainer may be a hollow body made of a porous material.

The hollow body may be an open ended tube made of a cardboard material.

The hollow body may contain a carrier which may be a fibrous material shaped and sized to fit within the hollow body and impregnated with a vapourisable deodorant and/or disinfectant and/or fragrance.

The carrier may be a hollow body made of a porous material and impregnated with a vapourisable deodorant and/or disinfectant and/or fragrance.

The hollow body may be an open ended tube made of a cardboard material.

At least one of the open ends of the tube may be sealed by an end cap.

Preferably, both of the open ends of the tube are sealed by end caps.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will now be described in more detail, by way of example WO 98/26703 PCT/GB97/03343 6 only, with reference to the accompanying drawings in which: Figure 1 is a pictorial view of one type of hand dryer of the invention with a plastics carrier retainer and carrier mounted on the back plate of the dryer housing; Figure 2 is a plan view of the interior of the dryer showing the location of the carrier retainer and carrier; Figure 3 is a sectional side view on 3-3 in Figure i; Figure 4 is a pictorial view of the dryer of Figure 1 with a carrier envelope mounted on the back plate of the dryer housing; Figure 5 is a plan view of the interior of the dryer showing the location of the carrier envelope; Figure 6 is a sectional side view on 6-6 in Figure 4; Figure 7 is a pictorial view of another type of hand dryer of the invention with a pair of plastics carrier retainers and carriers mounted on the opposed side walls of the dryer housing; Figure 8 is a plan view of the interior of the dryer on 8-8 showing the location of the carrier retainers and carriers; WO 98/26703 PCT/GB97/03343 7 Figure 9 is a sectional side view on 9-9 in Figure 7; Figure 10 is a pictorial view of the dryer of Figure 7 with a pair of carrier envelopes mounted on the opposed side walls of the dryer housing; Figure 11 is a plan view of the interior of the dryer on 11-11 showing the location of the carrier envelopes; Figure 12 is a sectional side view on 12-12 in Figure Figure 13 is an exploded pictorial view of the carrier retainer and carrier(s) shown in Figures 1 to 3 and 7 to 9; Figure 14 is a pictorial view of the carrier envelope(s) shown in Figures 4 to 6 and 10 to 12; Figure 15 is a cross-section through the carrier envelope shown in Figure 14; Figure 16 is a pictorial view of the hand dryer of Figure 1 with a tubular carrier retainer and carrier mounted on the back plate of the dryer housing; Figure 17 is a plan view of the interior of the dryer showing the location of the tubular carrier; Figure 18 is a sectional side view on 18-18 in Figure 16; WO 98/26703 PCT/GB97/03343 Figure 19 Figure 20 Figure 21 Figure 22 Figure 23 Figure 24 Figure 25 Figure 26 is a pictorial view of the dryer of Figure 7 with a pair of tubular carrier retainers and carriers mounted on the opposed side walls of the dryer housing; is a plan view of the interior of the dryer on 20-20 showing the location of the carrier retainers and carriers; is a sectional side view on 21-21 in Figure 19; is a pictorial view of the tubular carrier retainer and carrier shown in Figures 16 to 21; is a pictorial view of a tubular carrier of the invention including end caps; is a side view of a carrier system in the form of a plastic or glass receptacle containing a liquid deodorant and/or disinfectant and/or fragrance and also containing a wick; is a side view of a carrier system comprising an openable container containing the deodorant and/or disinfectant and/or fragrance; is a side view of a carrier system comprising an openable container containing the deodorant and/or disinfectant and/or fragrance; and WO 98/26703 PCT/GB97/03343 9 Figure 27 is a pictorial view of the hand dryer of Figure 1 with a carrier retainer and carrier mounted at the bottom of the dryer housing.

DESCRIPTION OF PREFERRED EMBODIMENTS The method of disinfecting and/or deodorising and/or imparting a fragrance to air emitted from a hot air hand dryer involves placing a disinfectant and deodorant and fragrance mixture-impregnated carrier within the dryer, so that the deodorant/disinfectant/fragrance mixture circulates within the dryer and is entrained in hot air emitted from the dryer to disinfect and/or deodorise and/or impart a pleasant fragrance to it. It has been found that with this method the interior of the dryer and the surfaces of the dryer are also continuously disinfected thereby preventing the growth of disease-causing bacteria and other pathogens in the moist warm interior of the dryer. It also imparts a pleasant fragrance to the air emitted from the dryer which makes it pleasant to use.

The figures show six alternative forms of deodorant/disinfectant/fragrance mixture-impregnated carrier in two different types of hot air hand dryer.

In Figures 1 to 3 the hot air hand dryer 10 comprises a housing formed by a base in the form of a back plate 12 which is attachable to a wall or other support structure and a cover 14 which is pivotally attached to the back plate 12. The cover 14 defines a cool air inlet 16, shown clearly in Figure 3, and a hot air outlet 18. A fan arrangement 20 is attached to the cover 14. A carrier retainer 19, of the type shown in Figure 13, containing a carrier impregnated with a liquid deodorant/disinfectant and fragrance imparting- WO 98/26703 PCT/GB97/03343 mixture, is attached to the back plate 12. The carrier retainer 19 is substantially as described in South African Patent Application No. 96/8157.

It is located at some distance from the air inlet 16 and the air outlet 18 to prevent rapid evaporation of the mixture and desiccation of the carrier which would occur if it was in the direct path of the inlet or outlet. In this position, there is still sufficient air passing over the carrier and sufficient heat to cause sufficient of the mixture to be entrained in the hot air emitted through the air outlet 18.

The carrier retainer 19 shown in Figure 13 comprises a polypropylene cover 31 and a base 40. The base 40 may be attached to the surface of the dryer by adhesive. The A.B.S or polypropylene base 40 has a series of clips 42 extending from it. The clips 42, which hold the cover against the surface of the dryer, clip into recesses 44 formed in the cover 31. The cover 31 is sized to accommodate and retain a carrier 26 in the form of a fibrous web of a liquid deodorant/disinfectant/fragrance-mixture impregnated material.

The carrier can also be in the form of a solid plastics material, for example polyvinyl chloride (PVC), which has been impregnated with the deodorant/disinfectant/fragrance-mixture or admixed with this mixture prior to moulding. The plastics carrier controls the release of the mixture, helping to ensure its sustained release.

The carrier 26 is contained within a polyethylene sleeve 48. This sleeve 48 ensures that the liquid disinfectant/deodorant/fragrance mixture does not leak into the interior of the dryer and is also not evaporated too quickly.

However, it also has an osmotic- or wick-type effect on the liquid mixture, allowing its transmission through the sleeve and into the atmosphere. The rate of transmission of the liquid mixture can be controlled by increasing or decreasing the thickness of the polyethylene sleeve.

WO 98/26703 PCT/GB97/03343 11 A plurality of apertures 37 are defined in the exposed surface 33 of the cover 31 so that as air passes over the apertures 37, the liquid within the carrier 26 is vaporised. The apertures 37 are arranged in three parallel rows.

The bottom row contains the largest apertures. These larger apertures are at the bottom when the carrier retainer is mounted in position and ensure a greater flow of air to the carrier, and thus greater entrainment of the disinfectant/deodorant/fragrance mixture. The liquid deodorant/disinfectant/fragrance mixture within the carrier tends to accumulate at the bottom edge of the carrier, where the larger apertures are situated, thus ensuring a greater entrainment of disinfectant/deodorant/fragrance mixture. Alternatively, the cover of the carrier retainer may be rotated through 1800 so that the larger apertures are in an upper position to restrict the passage of air over the carrier at its bottom edge and thus to restrict evaporation from the carrier.

The size of the carrier retainer, the size of the carrier and the thickness of the sleeve within which the carrier is contained may be varied, depending on the specifications of the dryer, to regulate the amount of mixture that is evaporated.

The carrier 21 shown in Figures 4 to 6 is of the type shown in Figures 14 and 15. It is positioned in substantially the same place as the carrier retainer and carrier in Figures 1 to 3.

The carrier 21 shown in Figures 14 and 15 (not to scale) comprises an elongate envelope 50, approximately 120mm long and 50mm wide, which is made of a flexible porous material. The flexible porous material is a nonwoven fibrous material which may be viscose or rayon or a mixture of the two or which may be a non-woven plastics material such as polypropylene.

WO 98/26703 PCT/GB97/03343 12 The envelope is heat sealed closed along its bottom end and along one of its sides. Its top end is also sealed and contains an eyelet 52 which can be used to suspend it within the dryer.

The envelope 50 of the carrier 21 contains a particulate biodegradable carrier material 54, which is sawdust or wood chips or wood shavings or a powder, such as sodium sulphate, which is not an environmental pollutant, or vermiculite, which is impregnated with the mixture containing a disinfectant/deodorant/fragrance mixture. The rate of evaporation of the mixture from the carrier within the envelope can be regulated by varying the thickness of the envelope and by varying the amount of liquid that is impregnated into the carrier material.

The fact that the mixture is impregnated into a carrier, and is therefore dry, allows it to be incinerated after use. This is an advantage over liquid disinfectants which present disposal problems as they may contaminate ground water. The porous material of the envelope 50 allows the gradual passage of vaporised mixture through it to the surrounding air. Chemical additives may be added to the particulate material or to the mixture to retard chemically the vaporisation of the mixture. This ensures that there is prolonged and even vaporisation of the mixture.

In Figures 7 to 9 and Figures 10 to 12 a different hot air hand dryer, generally designated 30, is shown. It also comprises a housing formed by a base in the form of a back plate 32 which is attachable to a wall or other support structure and a cover 34. A fan arrangement 38 is attached to the base plate 32. The back plate 32 has air inlet vents 33 defined in it and an air outlet 36 is defined in the cover 34. In Figures 7 to 9 two carrier retainers and carriers 19, as described above, are attached to opposed side WO 98/26703 PCT/GB97/03343 13 walls of the cover 34. In Figures 10 to 12, two carrier envelopes 21, as described above, are attached to opposed side walls of the cover 34. Again, in this position they are located at some distance from the air inlet vents 33 and air outlet 36 to prevent rapid evaporation of the mixture and desiccation of the carrier.

The carrier retainer 60 shown in Figures 16 to 22 comprises an open ended cardboard tube 62 which is approximately 1.5mm to 2mm thick and which has a length of approximately 150mm and an outer diameter of from to 20mm. The carrier pad 64 is a tubular pad, approximately 4mm thick and made of a viscose or rayon fibre, and which is dimensioned to be inserted into the tubular cardboard carrier retainer 62 along the entire length thereof or part of the length thereof. The carrier 64 is impregnated with the mixture once it is in position in the carrier retainer 62. It is impregnated by introducing the fluid through the hole in the centre of the tube 62. The mixture permeates gradually through the cardboard tube. The tube may also be filled with gypsum in a dry or gel form which is impregnated with the mixture and which delays release of the mixture.

The rate of evaporation of the mixture is controlled chemically by the inclusion of isopropyl myristate (IPM), an oily base, into the mixture. An example of a formulated mixture is 8ml of IPM, 10 ml of disinfectant and 32 ml of fragrance.

The rate of evaporation of the mixture from the carrier could also be controlled by the density of the cardboard used for the carrier retainer 62 or the thickness of the carrier retainer or the thickness of the tubular pad 64.

The carrier shown in Figure 23 comprises the same open ended cardboard WO 98/26703 PCT/GB97/03343 14 tube 62 shown in Figures 16 to 22. However, it contains no carrier pad.

Instead, the tube itself forms the carrier and is impregnated with a liquid deodorant/disinfectant/fragrance mixture. The ends of the tube are sealed by plastic end caps 63 which effectively retard the speed of evaporation of the liquid disinfectant/deodorant/fragrance mixture. The cost of the carrier is reduced because no carrier pad is required. Production and assembly is also made easier. The length of the tube and the thickness can be varied depending on the dimensions of the dryer and the desired rate of vapourisation.

As can be seen from Figures 16 to 21, the carrier retainer 60 is held in position on the back plate or side wall of the hand dryer by clips 66 which are dimensioned to hold the tubular carrier 62 in position while also allowing its easy removal and replacement.

The carrier may also be a plastic or glass receptacle 70 containing liquid deodorant and/ordisinfectant and/or fragrance and also containing a wick 72 made of felt or other fibrous material inserted through an aperture in the receptacle, typically the neck 74 of the receptacle, into the liquid in the receptacle to facilitate evaporation of the liquid. This alternative carrier system is illustrated in the attached Figure 23.

The rate of evaporation of the liquid from the receptacle 70 is controlled by varying the length of the wick 72 exposed to the air. The rate of evaporation of the liquid from the receptacle 70 could also be controlled by the inclusion of isopropyl myristate (IPM) into the liquid. The receptacle is held in position by a holder 76, which may be made of plastic or metal and which is dimensioned to fit snugly around the receptacle 70. The holder 76 is attachable to the back plate 12 of the housing of the hot air hand dryer WO 98/26703 PCT/GB97/03343 or to a side wall of the cover 34 of the hot air hand dryer 30 by way of screws or adhesive. A typical holder is about 50mm wide, 20mm deep and about 40mm high.

Another alternative form of carrier system is illustrated in the attached Figures 24 and 25. It comprises an openable container 80a or 80b, which may be shaped as shown in Figure 24 or Figure 25, containing the deodorant and/or disinfectant and/or fragrance admixed with a heavy gel or wax to control the evaporation or vaporisation of the deodorant and/or disinfectant and/or fragrance. The containers 80a and 80b have lids 82a and 82b respectively with apertures 84a and 84b respectively defined therein. The evaporation or vaporisation is controlled by varying the density of the gel or wax and also by varying the surface area of the mixture exposed to the air.

This is achieved by varying the shape of the container or the size of the aperture 84a or 84b in the lid. These carriers can also be held in position by a holder 83 which may be made of plastic or metal and which is dimensioned to fit snugly around the openable container 80a or The holder 83 comprises flexible fingers 86 which are adapted to fit around the openable container 80a or 80b to keep it in position. The holder 83 may be attached to the back plate 12 of the housing of a hot air hand dryer 10 or to a side wall cover 34 of the hot air hand dryer 30 or to the base of the cover 14, adjacent the air inlet 16, as shown in Figure 26, by way of screws or adhesive.

The liquid deodorant/disinfectant/fragrance mixture contains a pleasant smelling perfume as well as a disinfectant and a biocide. It will be appreciated that the percentages of the constituents of the deodorant/disinfectant/biocide may be varied depending on local conditions WO 98/26703 PCT/GB97/03343 16 and applicable environmental regulations, and also on the degree of disinfectant/biocidal efficacy required. The mixture is a liquid which may comprise about 80% deodorant/fragrance, and about 20% of disinfectant/biocide. The biocide typically comprises the following constituents: triethylene glycol (less than 98% glutaraldehyde (less than 4% phenyl ethyl alcohol (less than 3% and glycerolpolyethylene-glycoloxystearate (less than 3% m/m).

The deodorant/disinfectant/fragrance mixture is specially formulated to be effective against Escherichia coli, Staphylococcus aureus, Streptococcus feacalis and Proteus vulgaris.

The entrained disinfectant/deodorant/fragrance mixture ensures that no bacteria is transferred to the hands of a user drying his or her hands. It also acts as an aerial bactericide, killing bacteria and other microorganisms floating the space within the dryer and around it. The general washroom and toilet environment in and around a hand dryer of the invention is thus deodorised and disinfected, typically for between 30 and 35 days. However, if the dryer is extensively used, the period may be decreased to a week or a fortnight.

Claims

1. A method of disinfecting a hand dryer, and a stream of air emitted from the hand dryer comprising dispensing vaporised disinfectant into or in proximity to the dryer so that the disinfectant circulates in an area in proximity to and within the dryer and is entrained in the stream of air emitted from the dryer, the disinfectant including triethylene glycol.

2. A method according to claim 1 which also comprises the step of deodorising the hand dryer and the stream of air emitted from the hand dryer by dispensing vaporised deodorant into or in proximity to the dryer so that the deodorant circulates in an area in proximity to and within the dryer and is entrained in the stream of air emitted from the dryer.

3. A method according to claim 1 or 2, wherein the disinfectant and/or deodorant is in the form of a vaporisable liquid contained within a carrier. 15

4. A method according to claim 3, wherein the vaporisable liquid comprises each of the deodorant and disinfectant.

A method according to claim 3 or 4, wherein the carrier is located within the dryer.

6. A method according to claim 5, wherein the carrier is attached to an inner surface or sidewall of the dryer and out of a direct air stream.

7. A hand dryer comprising a housing and a liquid or solid carrier impregnated with a disinfectant including triethylene glycol positioned in or on the housing for disinfecting the dryer and a stream of air emitted from the dryer.

8. A hand dryer according to claim 7, in which the carrier is also impregnated with a liquid or solid deodorant.

9. A hand dryer according to claim 8, wherein the disinfectant and/or deodorant is in the form of a vaporisable liquid.

A hand dryer according to claim 9, wherein the vaporisable liquid comprises each of the disinfectant and the deodorant.

11. A hand dryer according to any one of claims 7 to 10, wherein the housing comprises a base and a cover.

12. A hand dryer according to claim 11, wherein the base defines an air inlet and the cover defines an air outlet and wherein a carrier is positioned on each of two opposed side walls of the cover and out of a direct air stream.

13. A hand dryer according to claim 11, wherein the cover defines an air inlet and an air outlet and wherein the carrier is positioned on the base and out of a direct air stream.

14. A hand dryer according to any one of claims 7 to 13, wherein the carrier is a fibrous material or a plastics material impregnated with a vaporisable deodorant and/or disinfectant and/or fragrance.

A hand dryer according to claim 14, wherein the carrier is an insert made of a fibrous material impregnated with a vaporisable deodorant and/or disinfectant and/or fragrance and contained within a hollow carrier retainer made of a porous material.

16. A hand dryer according to any one of claims 7 to 13, wherein the carrier is a hollow body made of a porous material.

17. A hand dryer according to claim 16, wherein the hollow body is an open ended tube made of a cardboard material.

18. A hand dryer according to claim 17, wherein at least one of the open :ends of the tube is sealed by an end cap.

19. A hand dryer according to claim 17 or claim 18, wherein both of the open ends of the tube are sealed by end caps.

A hand dryer according to any one of claims 7 to 13, wherein the 20 carrier is a particulate material contained within an elongate envelope made of a flexible porous material.

21. A hand dryer substantially as herein described with reference to and/or as illustrated in the accompanying Figures. Dated this second day of March 2001 Castlegate Trading Limited Patent Attorneys for the Applicant: F B RICE CO