[0001] This invention relates to air purifying means.

|0002] Titanium dioxide when subject to Ultra Violet light has many advantageous results. It acts effectively, yet safely without harmful or toxic effects to

5 human or animal life, as a sterilizer, disinfectant, germicide, antiseptic and sanitizer.

A problem with titanium dioxide is that it is often difficult to place it in position in which it can remain for lengthy periods of time to provide the aforesaid results. For example attempts have been made to mount the titanium dioxide on to a substrate such a wall of a chamber 'containing an ultraviolet light by means of bonding medium. The0 bonding medium tends to coat the titanium dioxide nano particles so that these are unable to act appropriately.

[0003] According to one aspect of the invention there is provided a substrate at least the surface of which is impregnated with titanium dioxide nano-particles. The substrate may comprise a woven or non-woven cloth which is formed with fine fissures and interstices and which is resistant to ultra violet light such as polyester.

[0004] Alternatively the substrate may comprise a material having fine fissures and interstices such ceiling board, into which the nano-particles can be received and retained. A further substrate can be a sheet of paper of paper like material that has at least its outer surface impregnated with titanium dioxide nano-particles. This sheet of ) paper may be applied to the exposed surface of an under-substrate such as a ceiling tile. 10005 J The cloth mentioned above may be formed into strips which may be mounted into direct sunlight so that the ultra violet light in the sunlight activates the titanium dioxide. Advantageously the strips may be arranged to form Venetian blinds and in particular vertical Venetian blinds. These can in use be mounted adjacent a window or the like through which sunlight streams to activate the titanium dioxide. Alternatively one or more strips of the cloth may be mounted in the windows of a vehicle, such as a taxi, bus or minibus and die titanium dioxide will be activated during the day when the sunshine passing through the windows engages the strip or strips.

[0006] According to another aspect of the invention there is provided an air purifying device including a chamber having openings therein through which air in the chamber may pass into the atmosphere, mounting means for mounting an ultraviolet light in the chamber for treating air passing therethrough, and one or more units of substrate, preferably cloth, impregnated with titanium dioxide within the chamber. The cloth units may be mounted in such a way that they do not cover the openings. Typically the chamber may comprise walls surrounding an ultra violet light when mounted in the mounting means, wherein the impregnated substrate units are attached to one or more of the said walls.

[0007J The connection between the impregnated substrate units and the wall is preferably impermanent so that the units may be removed for cleaning or replacement. The chamber may comprise sheet ferro magnetic metal bent into the appropriate shape to form the walls of the chamber. The cloth units may be attached to the wall by means of clips or the like. The units may be clamped between parts of the device or to fit within pairs of facing channels formed in the device. Alternatively the cloth may be attached to magnet means which are applied to one or more of the metal walls to mount the strips on the chamber.

[0008J According to another aspect of the invention there is provided the combination of an air conditioning device as set out in the preceding paragraphs with ultra violet light emitters mounted in the mounting means.

[0009J According to a further aspect of the invention there is provided sterilizing means comprising a member having a surface impregnated with titanium dioxide nano particles and one or more fluorescent lights, the arrangement being such that the light from the fluorescent light tubes when illuminated impinges upon the said surface of the member. The sterilizing means preferably comprises a ceiling consisting of ceiling boards forming the said members, the under surfaces of which ceiling boards are impregnated with titanium dioxide nano particles and the fluorescent light is arranged to direct at least a portion of the light emitted thereby to impinge upon the under surface of the ceiling boards. The fluorescent lamp is preferably an elongated fluorescent light tube.

[OOIOJ The ceiling is preferably a suspended ceiling comprising a plurality of ceiling boards carried by suspension members each of which comprises a vertical carrier that may be attached to a supporting part of the roof and, at its lower end, outwardly directed flanges that carry the ceiling boards. Conveniently each suspension member carries a downwardly open channel at its lower end, the channel incorporating elongated electrical contactors preferably carried by elongated insulated housings. The arms of the channel carry the outwardly directed flanges. Inwardly directed flanges are also carried by the arms of the channel to retain the electrical contactors. In the alternative, the suspension members are in the form of inverted "T" section members, the cross part of the "T" constituting the flanges and there is further provided a downwardly open channel attached to the cross-part of the "T" and carrying therein elongated electrical contactors preferably carried in elongated insulated housings. A connector part is preferably formed on the upper face of the web of the channel, which connector part is adapted to engage the cross-part to secure the channel to the cross-part.

[0011] One or more luminaires including fluorescent tubes may be carried by the channel. Each luminaire preferably comprises a stand part with upstanding ends into which the connection ends of the fluorescent tube may engage. The stand part preferably has, on its side opposite to the ends, projection members which can fit into the channel and these projection members have contacts to engage and be electrically in contact with the electrical contactors.

[0012] We have found that when subjected to visible light at wavelengths close to that of ultra violet light, titanium dioxide has the same affect as when subject to ultra violet light, i.e. it acts effectively yet safely without harmful or toxic effects to human or animal life as a sterilizer, disinfectant, germicide, antiseptic and sanitizer although these results are slightly attenuated. In particular we have found that the light emitted by fluorescent tubes activates titanium dioxide to give these results. Because of the nano particles of titanium dioxide spread over the large area of the ceiling even these attenuated results provide for very satisfactory sterilizing, sanitizing etc.

[0013] The sterilizing means may also comprise a lamp including a fluorescent light and a lamp shade surrounding the light, the inside surface of the lamp shade being impregnated with titanium dioxide nano particles. [0014] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings.

[0015] In the drawings :-

Figure 1 is a perspective view from above of an air conditioning device of the invention;

Figure 2 is a perspective view from below of the device of Figure 1 ; Figure 3 is a side view of the device of Figure 1; Figure 4 is a section on line 4 - 4 of Figure 3; Figure 5 is a perspective view of the substrate; Figure 6 is a perspective view from above, the front, and one side of a freestanding air conditioning device of the invention; Figure 7 is a front view of the device of Figure 6 with the front surface partially broken away;

Figure 8 is a section on line 8 - 8 of Figure 7; Figure 9 is a section on line 9 - 9 of Figure 8; Figure 10 is a front view of a sign embodying the present invention; Figure 11 is an under plan of the sign; Figure 12 is a section on line 12 - 12 of Figure 11 ; Figure 13 is a plan of the sign;

Figure 14 is an under view of a detail of a ceiling of the invention; Figure 15 is a detail section through the ceiling taken along line 15 - 15 of Figure 9 but showing part of a luminaire;

Figure 16 is a detail section through the ceiling taken along line 16 - 16 of Figure 9; Figure 17 is a view in the direction of arrow 17 of Figure 16 with the ceiling panels omitted; Figure 18 is a plan of a detail of the modified ceiling; Figure 19 is a section on line 19 - 19 of Figure 18; Figure 20 is a titanium dioxide nano scale radiation chart; and Figure 21 is a perspective view of a table lamp of the invention.

[0016] Referring now to Figures 1 to 5 there is shown an air purifying device 10 of the invention. The device 10 comprises an elongated container 12 formed from bent, powder coated, sheet ferro magnetic material such as steel. Within the container 12 is a chamber 14 in which is a mounting means 16 that receives a pair of horizontal ultra violet lamps 18. The chamber 14 is defined between upper and lower elongated horizontal plates 20 and 22 and two end plates 24 and 26. The upper plate 20 has its side ends 28 turned up at right angles. The side ends 30 of the lower plate 14 are outwardly inclined towards the upper plate 20 and leave a narrow gap 32 running the length of the chamber 14.

[0017] The upper ends 34 of the end plates 24 and 26 are of slightly reduced width and pass through slots (not shown) in the upper plate 20 and stand proud thereof. A downwardly open channel member 36 is placed above the upper plate 20 to form an upper space 38. It has an opening 40 (see Figure 1) through which a power cable can enter the space 38 and a pair of co-axial arcuate slots 42 through which fastening means can pass to fix the device to a ceiling or the like. Secured to the underside of the web 44 of the channel member 36 is a connector means (illustrated diagrammatically at 46) to which the power cable can be connected and which is connected to a connector cable (not shown) leading to the mounting means 16. The channel member 36 has closed ends (not shown) which rest beside the upper end 34 and are connected thereto by screws. [0018J Formed in the upper plate 20 are a series of windows 50 (best shown in

Figure I.

|00l 9] Carried below the lower plate 22 is another channel member 52 with closed ends 54 that forms a lower space 56. Within the space 56 are a pair of fans 58 contained respectively in ducts 60. The ducts 60 are located adjacent lower openings 62 in the web of the member 52 and upper openings 64 in the lower plate 22. The lower openings 62 are closed by a wire protector 66. The fans 58 draw ambient air into the chamber 14 where it is treated by the lamps 18 and from whence it escapes to the atmosphere through the gaps 32 and windows 50. An air ioniser 68 is provided on the underside of the web of the channel member 36.

[0020] Clamped between the upper surface of the upper plate 20 and the lower edges of the channel member 36 is a cloth member or unit 70. The cloth member 70 extends between the side ends 28 and covers the windows 50.

[0021] The cloth member 70 consists of a loose non-woven material substrate 72 which is of an ultraviolet resistant type such as white or translucent polyester and which has formed therein interstices and/or fissures. The material substrate 72 has an appearance as indicated in Figure 5 with regular small square openings 74. The material substrate 72 is impregnated with titanium dioxide nano-particles (not shown). The material substrate 72 is prepared by soaking it in an emulsion of nano-particles for a period of half an hour and then drying it. In this way the nano-particles will be embedded on both sides of the substrate and will in any case present a greater area to be actuated by the Ultra violet light. The nano-particles will cover the openings 74. The substrate is fairly rigid. Its thickness is about 0,5mm. [0022J It will be noted that the cloth member 70 will be subject to ultra violet light which passes through the windows 50. Therefore the cloth member 70 being polyester must be and is resistant to ultra violet light.

10023] On the upper surface of each of the inclined side edges 30 is a cloth unit being a pleated (or "fan fold") cloth strip 74. The ends of the strip 74 are secured to the ends of the side edges 30 by an elastic clip 78. Each strip 74 comprises the same material as does the cloth member 70, i.e. a substrate impregnated with titanium dioxide nano particles formed in the manner described.

[0024J The air purifier operates as follows: Air is blown through the chamber 14 by the fans 58. As it passes through the chamber 14, the air is treated by the ultra-violet light which kills germs and bacteria in the air. The ultra violet light also acts on the titanium dioxide nano-particles in the cloth member 70 and the pleated cloth strips 74 to form OH radicals to provide stronger oxidation of the air and hence improved air purification.

[0025] I have found that by having a large surface of cloth substrate coated with the titanium dioxide nano-particles the efficacy of the of the catalytic effect of the titanium dioxide is increased. I have further found that having the titanium dioxide embedded in the substrate prevents loss of efficacy of the titanium dioxide due to surface loss as occurs when the titanium dioxide is bonded in a bonding agent which encapsulates the nano-particles limiting their efficacy. By providing the pleated strip 74, an increased area of titanium embedded substrate is provided to increase still further the effect of the titanium dioxide. With use over a period of time, dust may form on the surface of the substrate which may have a deleterious effect on its efficacy. When this occurs, the cloth 70 and/or the pleated cloth strips 74 may easily be removed from the upper surface of the upper plate 20 and the upper surfaces of the inclined side edges 30 of the lower plate 22 and be replaced by fresh member/s which would be clamped in the same manner as described above.

[0026J Reference is now made to Figures 6, 7, 8 and 9.. Here is shown a free standing air purifier device 100 of the invention. The device 100 comprises an elongated container 102 formed from bent powder coated sheet ferro magnetic material such as steel. The front face of the container 102 is open and has its edges formed by channels 104. Within the container 102 is a chamber 106 in which is a platform 108 spaced at its side edges from the side walls of the chamber 106. The platform 108 carries mounting means 110 that receives a pair of vertically arranged ultra violet lamps 1 12. A set of inlet openings 114 are provided at the lower part of one side 116 of the container 102 leading to the chamber 106. Above the chamber 106 is a fan compartment 1 18 containing a fan 120. The fan 120 draws air through the openings 1 14, around the platform 108 and through the chamber 106 and discharges the air into the atmosphere through an outlet opening 122 provided in a rigid plastic plate 124 forming the front face of the container 102. To improve air flow the fan 120 is contained within a duct 126.

[0027] The plate 124 is removably carried by the container 102 by having its edges slidable received in the channels 104.

100281 A tube of titanium dioxide impregnated substrate material 128 lines the inside of the side and rear walls. The edges of the tube are wound around the inner flanges of the channels 104 and are held thereto by means of clips 130 (shown only in Figure 7). The tube partially surrounds the lamps 1 12. An additional, front, panel of substrate material 132 is placed on the inside of the plate 124 with its edges received within the channels 104. Thus the light from the lamps impinges and activates the titanium dioxide to excite it to generate OH radicals. It will be seen that there is a subs- tantial exposed area of substrate material and that this surrounds the lamps 1(38. The material 128 and 132 is substantially identical to the lining material 56 described above.

[00291 I have found that the provision of the titanium dioxide substrate material 128 and 132 significantly enhances the operation of the air purifier device 100 in the same manner as it enhances the that of the device 10.

[0030] It will be seen that the interior of the container is readily accessible to replace the lamps 112. Furthermore the substrate parts 128 and 132 are easily replaceable.

[003 IJ Reference is now made to Figures 10, 11, 12 and 13. Here is shown a free standing sign and air purifier device 200 of the invention. The device 200 com- prises an elongated container 202 formed from bent powder coated sheet ferro magnetic material such as steel which form an internal chamber 204. The front and rear faces 206 and 208 of the container 202 are open and removably receive translucent acrylic panels 210 on to which advertising or similar matter is printed. The container 202 internally carries mounting means 212 that receives a pair of horizontally arranged ultra violet lamps 214. A pair of inlet openings 216 are provided at the lower face 218 of the container 202 leading to the chamber 204. Above the openings 216 are fans 220. The upper surface 222 of the container 202 has a large elongated outlet opening slot 224. The fan 220 draws air through the openings 216 and then through the chamber 204 and discharges the treated air into the atmosphere through a outlet opening 224.

[0032J Removably mounted on the inside surfaces of the panels 210 are sheets 226 of titanium impregnated substrate which are substantially identical to _. the _. lining material 56 described above. The sheets may be plane or may be pleated as shown.

[0033] In use, the ultra violet lamps 214 will give off sufficient light to pass through the illuminate the rear of the panels 210 through the translucent sheets 226. In addition the lamps 214 serve to purify the air being drawn through the chamber 204. The titanium dioxide substrate material 226 enhances the operation of the air purifier device 100 in the same manner as described above.

[0034J In a further embodiment of the invention which is not illustrated a suitably strong substrate is embedded with titanium dioxide nano-particles and formed into strips that may be used as vertical members of a vertical Venetian blind. Such a blind would be mounted near to a window so that the sun's rays, especially those of less than 400nm wavelength, strike it. The air in the room will be circulated past the blinds giving the same germicidal catalytic properties mentioned above. Furthermore if desired one or more strips of the cloth may be mounted on or adjacent the inside of some of the windows of a vehicle, such as a taxi, bus or minibus or a train and the titanium dioxide will be activated during the day to give off OH radicals when the sunshine passing through the windows engages the strip or strips. This serves to disinfect and/or sanitise the. air within the vehicle. [0035] It will be noted that there are large visible metal surfaces on the air conditioning units 10 and 100. Advertising or similar matter can be applied to these surfaces. The advertising may be silk screened on to the surfaces or may be applied to material which is attached to the unit, conveniently having a transparent cover.

[0036| We have found that the provision of the titanium dioxide impregnated sheets 226 enhances the operation of the air purifier device 200 as it enhances that of the device 10.

[0037] The effect of the substrate 96 can be further enhanced by bending it into a "fan-fold" shape before forming it into a tube. This is because the surface area of the substrate will now be greatly increased.

10038] Referring now to Figure 14 there is shown the underside of a suspended ceiling 410 of the invention covering a space such as a room. The ceiling 410 comprises a number of ceiling panels 412 of any desired material and thickness which may be fire proof, acoustic, decorative or otherwise. The size of the panels 412 are conveniently 1200 mm x 600 mm or 600 mm x 600 mm. These panels are porous with fissures and interstices. The panels 412 are arranged in rows. The panels 412 are supported at their edges 414 by metal suspension members 416, which will be described more fully below, and consequently will extend in rows across the ceiling 410. The undersides 418 of the panels 412 are coated or impregnated with titanium dioxide nano particles (indicated at 420) as will be described more fully below.

[0039] Each suspension member 416 may be formed by extrusion or by bent sheet metal. The suspension member 416 comprises a longitudinal extending vertical carrier 422 which may be attached to a supporting part of the construction (not shown). At its lower end the carrier 422 carries a longitudinally extending channel member 424, being attached centrally to the web 426 thereof. The arms 428 of the channel member 424 each terminate in transverse end parts 430 which constitute outwardly directed flanges 432 and shorter inwardly directed flanges 434. The edges 414 of the ceiling panels 412 rest on the outwardly directed flanges 432 so that the ceiling panels 412 are carried thereby.

10040] The channel member 424 carries at each side an elongated electrically insulating plastic housing 438 with grooves 440 in their facing surfaces 442. Elongated copper connectors 444 are carried in the grooves 440. At one end of each channel member 424 is a set of electrical contacts (not shown) by means of which the connectors 444 are connected to a source of electrical power. The electrical contacts for all the channels are conveniently at one end of the room.

[0041 ] Each suspension member 416 carries a series of luminaires 448. Each luminaire 448 comprises an elongated stand part 450 containing the electronic control gear ("ECG") such as the ballast, starter etc. At each end of the stand part 450 is an upstanding end piece 452 with an appropriate socket 454 into which the connection ends of a fluorescent tube 456 may engage. On its side opposite to the ends 454, the stand part 450 has insert members 458 which are received within the channel and which have slip members 460 that engage the copper connectors 454 respectively. These insert members 458 have projecting flanges which fit into corresponding recesses in the facing surfaces 442 of the housings 438. Neither these flanges nor the recesses are shown in the drawings. 10042 J The spacing of the luminaires 448 can be as desired and generally depend upon the amount of lighting required in any particular part of the space. Thus if there is a desk at one part of the space there may be one or two luminaires 448 closely spaced thereabove as shown at 460. Where less light is required, the spacing between the luminaires 448 may be greater.

[0043] Reference is now made to Figures 18 and 19 wherein is shown a modified suspension member 464 which is of inverted T-shape with a vertical carrier 466 and a horizontal cross member 468 forming flanges 470 on either side of the carrier 466. The edges 414 of the ceiling panels 412 rest on the flanges 470 to support the ceiling panels 412 thereon. A channel member 474 which is very similar to the channel member 422 with inside flanges 475 (but without the outside flanges 428) runs beneath the cross member 468. It includes insulating housings 476 and electrical connector means 478 which are identical or substantially identical to the parts 444 and 446 described above. At suitable locations along the length of the channel member 474 there are provided connector plates 480. The connector plate 480 is pivotally mounted on a pivot pin 482 centrally located on the web 484 of the channel member 474. At diagonally opposed corners of the plate 480 there are holding parts 486 bent over the plate 480 with facing parallel inclined edges 488 spaced apart by a distance greater than the width of the cross member 468. The connector plate 480 is swung around the pivot pin 482 so that the cross member 468 can fit between the edges 488. The plate 480 is pressed upward and swung back so that the flanges 470 are received in the spaces between the holding parts 486 and the plate 480. The channel member 474 is thus carried by the flanges 470 through the intermediary of the holding parts 486. The number of connector plates 480 is appropriate to carry the mass of the channel member and parts carried thereby. [0044] The undersurfaces 418 of the ceiling panels 412 in both embodiments above described have titanium dioxide nano particles 420 applied to them. The ceiling panels 412 may comprise any suitable material, as mentioned above, with slight fissures or interstices into which the nano particles may fit and be held. The nano particles are applied by forming a suspension of nano particles in water (approximately 25: IQO v/v). The suspension is applied to the undersurfaces 418 of the ceiling panels 412 by means of a roller or paintbrush. Portions of the nano particles penetrate the ceiling material mechanically and form a continual activatable surface of titanium dioxide. The nano particles project beyond the undersurface of the ceiling panels for the purpose which will be described below. It will be understood that the nano particles are not encapsulated in a carrier but, being held by the ceiling panel material, are exposed therebelow.

[0045] When the fluorescent tubes are activated, light therefrom is directed on to the undersides 418 of the ceiling panels 412. It will be seen in particular that as the stand part 450 is narrow and as there are no side reflectors a substantial part of the light emitted by the fluorescent tube 456 will engage the undersides of the ceiling panels causing hydroxyl radical emission. This will cause the air to be oxidised killing bacteria and viruses present in the air. Consequently there will be a disinfectant and sterilising effect on the air in the space covered by the ceiling 410.

[0046] Reference is now made to Figure 20. This is a titanium dioxide nano-scale radiation chart. It will be seen that the nano particles will be best activated when subjected to ultra violet light. However as can be seen where visible light is emitted by the fluorescent tubes (at a wave length of 400 to 650 nano metres) this causes titanium dioxide also to act as described above although at a somewhat attenuated manner. However in view of the significant area of the ceiling panels against which the light from the fluorescent tubes impinge, sufficient hydroxyl radicals will be formed to sanitize the air in the space.

[0047] The ceiling arrangements as thus described can be used with advantage in hospital wards or in any other place where persons congregate such as doctor's waiting rooms, doctors consulting rooms, theatres, cinemas and even lifts and offices, ft will also be noted that as the space between the edges of the inward flanges of the channel member are small, the arrangements of these channel members are not aesthetically unpleasing.

[0048] Reference now made to Figure 21 wherein is shown a table light 490 of the invention. The light 490 comprises a stand 492 carrying a socket (not shown) in which is fitted a compact fluorescent lamp 494. Surrounding the fluorescent lamp 494 is a generally cylindrical lamp shade 496. The inside surface 498 of the lamp shade 496 is coated with titanium dioxide nano particles which have been applied in the same manner as described above and which are held on this surface mechanically. When the compact fluorescent lamp 494 is illuminated it activates the titanium dioxide nano particles as described above.

[0049] In a ^" further embodiment of the invention the substrate comprises paper impregnated with titanium dioxide nano-particles. This paper can be applied to an under substrate such as the ceiling tiles which therefore would not have themselves to be impregnated with the titanium dioxide nano-particles. The paper may be formed by adding a suspension of titanium dioxide nano particles in water to the stock in the head box of the paper making machine. Alternatively the suspension may be sprayed on to the sheet in the press section of the paper making machine. [0050] The invention is not limited to the precise constructional details hereinbefore described and illustrated in the drawings. For example, the Iuminaires may carry two or more fluorescent tubes. Other holding means may be provided to support a channel member on the inverted T-section supports. Also the lamp shade may be pleated. The light may have other shape and indeed may be a wall mounted or suspended light.

Further the linings can be applied to different air purifier devices using ultra violet light. The nano particles may be applied to the substrate by spraying. The substrate may comprise woven material and may be of different appearance to that mentioned above.

[005 IJ The linings can be applied to different air purifier devices using ultra violet light. The nano particles may be applied to the substrate by spraying or any other suitable means. The substrate may comprise woven material and may be of different appearance to that, mentioned above. The sign 200 need not be an illuminated sign. The substrate may be attached to the container by carrying one or more magnets thereon which adhere to the container.