Lighting means and method for obtaining lighting means

Lighting means and method for obtaining lighting means .

The invention relates to lighting means suitable for purifying the air and a method for obtaining this means. In domestic and industrial environments, or also in offices, shops or on public premises in general, lighting means with various conformations is used to take account of particular lighting requirements .

In such environments the need furthermore very often arises to purify and/or filter air, for example to remove smoke present on public premises, or the particulate generated for example by industrial processing, or the pollutants present in the air, such as NO_x, CO, VOC, SO_x, etc., or odours caused by a kitchen, to make the stay in such environments more pleasant . Furthermore, especially in public or humid environments, there is the need to eliminate possible viruses or bacteria present, to maintain a high standard of hygiene within such environments . The above functions are not performed by known lighting means .

An object of the invention is to provide improved lighting means .

A further object is to provide lighting means that prevents the proliferation of bacteria and viruses present in the environments in which it is provided for and enables them to be eliminated.

Another object is to provide lighting means that enables, in the environments in which it is installed, the formation of unpleasant odours to be prevented and/or enables them to be eliminated.

Still another object is to provide lighting means that has photocatalytic and/or anti-polluting properties . Another object is to provide lighting means that has durable self-cleaning properties in relation to organic compounds. In a first aspect of the invention, lighting means is provided comprising lighting source means for emitting radiation at least in the visible field, air treatment means for purifying the air in an environment in which said lighting means is provided, characterised by the fact that it comprises air circulating means for generating circulation of air in said lighting means .

In an embodiment, said air circulating means comprises air moving means arranged for moving the air in said lighting means . In another embodiment, said air treatment means comprises photocatalytic treatment means .

This enables lighting means to be obtained that in addition to lighting a given environment in which it is provided, treats the air in this environment, causing and accelerating the decomposition reactions of the substances, in particular of the gaseous and/or particulate polluting substances, which are completely oxidised until they prevalently form carbon dioxide (CO2) and water (H₂O) , and causing and accelerating the oxidising reactions of the inorganic substances, like NO_x and SO_x, in the atmosphere surrounding these lighting means. In an embodiment, said lighting means comprises lighting sources for emitting radiation in the wavelength interval comprised between 300 - 500 nm.

In particular, said lighting sources emit radiation in the length interval that is typical of ultraviolet radiation A (UVA) .

This enables the photocatalytic properties of the lighting means to be enhanced.

In another embodiment, said air treatment means comprises filter means arranged for filtering the air of said environments .

In a further embodiment said photocatalytic treatment means comprises layer means containing titanium dioxide, preferably in the form of Anatase. In a still further embodiment, said photocatalytic treatment means furthermore comprises further layer means in titanium dioxide in the form of Rutile or in other compounds with strong power of adhesion that are not oxidisable. The further layer means are interposed between said titanium dioxide photocatalytic treatment means in the form of Anatase and supporting means to which said layer means in titanium dioxide in the form of Anatase is applied. The further layer means enables the supporting means to be preserved from any chemical attacks, increases the insulating properties of the supporting means and promotes the adhesion of the layer means to the supporting means .

In a still further embodiment, said photocatalytic treatment means furthermore comprises still further layer means interposed between the supporting means and the layer means, or between the supporting means and the further layer means, if provided.

The still further layer means provide a better adhesion of the layer means to the supporting means, independently of the material of which the supporting means is made. The still further layer means acts as a "primer" enhancing the adhesion of the layer means and the stability over time thereof.

In a second aspect of the invention, a method is provided for obtaining lighting means comprising providing said lighting means with lighting sources for emitting radiation at least in the visible field, applying to said lighting means air treatment means for purifying the air in an environment in which said lighting means is provided, and furthermore installing air circulating means for generating circulation of air in said lighting means . In an embodiment, said installing comprises installing air moving means arranged for moving the air in said lighting means .

In another embodiment, said applying air treatment means comprises applying layer means comprising photocatalytic treatment means . In a further embodiment said applying comprises further applying further layer means .

In a still further embodiment said applying comprises still further applying still further layer means . This enables improved lighting means to be provided that comprises lighting sources, air treatment means, and photocatalytic means for purifying the air, said lighting means enables the air to be purified in an environment in which it is provided, since the air circulates inside the lighting means, both through convection, i.e. without any moving means of the air, and moved by suitable moving means of the air that circulates the air inside said lighting means .

In a third aspect of the invention, the use of titanium dioxide is provided that has photocatalytic properties for obtaining lighting means .

This enables lighting means to be obtained having photocatalytic properties for purifying the air of an environment in which said lighting means is installed. The invention may be better understood and implemented with reference to the attached drawings, that illustrate some embodiments thereof by way of non limitative example, in which:

Figure 1 is a schematic view of a first embodiment of lighting means according to the invention;

Figure 2 is a schematic view of a second embodiment of lighting means according to the invention.

Figure 3 is a perspective view of a version of the lighting means according to the first embodiment of the invention; Figure 4 is a perspective view of the lighting means of

Figure 3 in which the wall 200B has been removed;

Figure 5 is an exploded view of the lighting means of Figure

3;

Figure 6 1 a schematic view of the lighting means of Figure 2; Figure 7 is a cross section of the lighting means of Figure 6;

Figure 8 is a schematic view of a testing apparatus used for testing the functioning of the lighting means according to the invention;

Figure 9 is a graph showing the NO_x decay [ppm] over time [min] obtained with the testing apparatus in which the lighting means according to the first embodiment had been inserted, and with the lighting means switched off; Figure 10 is a graph showing the NO2 decay [ppm] over time [min] obtained with the testing apparatus in which the lighting means according to the first embodiment had been inserted, and with the lighting means switched off; Figure 11 is a graph showing the NO decay [ppm] over time [min] obtained with the testing apparatus in which the lighting means according to the first embodiment had been inserted, and with the lighting means switched off; Figure 12 is a graph showing the NO_x decay [ppm] over time [min] obtained with the testing apparatus in which the lighting means according to the first embodiment had been inserted, and with the lighting means switched on; Figure 13 is a graph showing the NO2 decay [ppm] over time [min] obtained with the testing apparatus in which the lighting means according to the first embodiment had been inserted, and with the lighting means switched on;

Figure 14 is a graph showing the NO decay [ppm] over time [min] obtained with the testing apparatus in which the lighting means according to the first embodiment had been inserted, and with the lighting means switched on; Figure 15 is a graph showing the NO_x, NO2 and NO decay [ppb] over time [min] obtained with the testing apparatus in which the lighting means according to the second embodiment had been inserted, and with the lighting means switched off; Figure 16 is a graph showing the NO_x, NO2 and NO decay [ppb] over time [min] obtained with the testing apparatus in which the lighting means according to the second embodiment had been inserted, and with the lighting means switched on; Figure 17 is a schematic section of a lamp provided with the lighting means according to the first embodiment of the invention, namely lighting means of Figures 1, 3, 4;

Figure 18 is a perspective view of a portion o the lamp of

Figure 17;

Figure 19 is an exploded schematic view of the lamp of Figure

18. With reference to Figure 1, 3, 4 there is shown a first embodiment of lighting means 1 comprising walls 2, first lighting source means 3 for lighting an environment in which the lighting means 1 is located and consisting, for example, of one or more lighting sources 4 for emitting radiation into the visible field, which may be of any known type, for example incandescent lamps, halogen lamps, fluorescent lamps, dichroic lamps, etc., and air treatment means 5 for treating the air inside the walls 2. The walls 2 comprise a first wall 2C and a second wall 2D that, together with the first opening 2A and the second opening 2B, define first chamber means 200 inside which the air treatment means 5 is inserted, as shown in the embodiment in Figure 1, furthermore, the walls 2 define second chamber means 200A inside which the first lighting source means 3 is fixed through suitable fixing means 31.

The second chamber means 200A comprises a wall 200B facing the zone to be lighted with the first lighting source means 3 shaped so as not to hinder but to enhance the lighting action of the first lighting source means 3, similarly, the second wall 2D of the first chamber means 200 is shaped to enhance the lighting action of the first lighting source means 3.

In the lighting means 1, there can be provided a number of first lighting source means 3 that can be varied freely on the basis of the requests of a user, such first lighting source means 3 can be furthermore actuated in groups independently of one another.

In an embodiment that is not shown, the first lighting source means 3 is inserted into the first chamber means 200 and fixed to the walls 2 by means of corresponding fixing means, in such an embodiment there being provided no wall interposed between the first lighting source means 3 and the zone to be lighted.

Some constructive particular of the lighting means 1 are not shown in the version of Figure 3 and 4.

In Figure 3, and 4 first lighting source means 3 is not present. In this version coupling means 60 arranged for receiving wall means suitable for forming second chamber means 200A shown are provided for. Possibly, first lighting source means 3 can be provided inside said second chamber means 200A.

The air treatment means 5, comprises further lighting sources

6 for emitting radiation suitable for activating Titanium particles as better describe in the following. Further lighting sources 6 can, for example, emit into the ultraviolet (UV) field, in particular the ultraviolet A (UVA) field.

The air treatment means 5, furthermore comprises air moving means, for example a suction fan 7, for sucking air inside the walls 2 shaped so as to generate forced air circulation inside the lighting means 1 in the direction indicated by the arrows F.

As further lighting sources 6 can also be used a LED lamp or any other lighting sources suitable for activating the photocatalytic properties of the photocatalytic treatment means .

The air moving means 7 can be positioned in the lighting means 1 both upstream and downstream of the air treatment means 5. In particular, the fan 7 acts so as to make air enter through the first opening 2A and so as to make it exit from the walls 2 through the second opening 2B.

The wall defining the first opening 2A can also be a grid 2A' , as shown in Figure 4, arranged to allow the passage of the air and also to protect the air treatment means 5 provided in to the first chamber means 200. The fan 7 can be of the axial or radial type. In some embodiments that are not shown, the fan 7 may also not be present, natural convection of the air present in the environment being sufficient to make the air circulate inside the lighting means 1, and in particular through air treatment means 5 for purifying the air of the environment in which the lighting means 1 is positioned. The fan 7 can be shaped in such a way as to operate at different suction speeds.

The air treatment means 5 furthermore comprises a plurality of filtering elements 8 arranged successively inside the walls 2 so as to be successively traversed by the air that enters from the first opening 2A.

The filtering elements 8 are provided with photocatalytic material .

These filtering elements 8 comprise in succession a prefilter 9 suitable for filtering particles of relatively great dimensions present in the sucked air, a filter 10 for particulate of very small dimensions, for example an HEPA® filter, with a desired filtering capacity, a further filter 11 titanium dioxide (TiC>2) -based having bactericide action for eliminating any bacteria present in the filtered air, the further filter 11 can also be of the ceramic type, known by the name "honeycomb", coated with titanium dioxide, a titanium dioxide (TiC>2) -based filter for gas 12 for eliminating any harmful gases present in the sucked air, the filter for gas 12 can also be of the ceramic type known by the name "honeycomb", coated with titanium dioxide, and a still further filter 13 for eliminating any residual unpleasant gases, for example an actived carbon filter of the type known commercially as "Odor Free®" .

The photocatalytic treatment means can be provided on any one filtering elements 8, or it can be also provided on more filtering elements 8.

The number, the characteristics and the spatial layout of the filtering elements 8 can be different from that precedently outlined.

The filtering elements 8, and in particular filters 11 and 12 having photocatalitycal properties, can comprise ceramic filters, possibly reticulated, with square section or with a section differently shaped.

Ceramic filters can be made of refractory materials preferably a material that can be subjected to a Temperature of about 138O⁰C or higher, the refractory material, being preferably present in the filters for about 90%; the remaining part, about 10%, comprising a material having a porosity comprised between about 32% and 36%, with pores with a diameter comprised between about 3 ± l,5μm, and preferably a number of cells for square inch of 16CSI, 25CSI, 50CSI,

64CSI, lOOCSI, 200CSI, 300CSI, 400CSI, 600CSI, the cells having a depth comprised between about 0,3 mm and 1.000 mm.

A mixing of different refractory materials can also be used.

The filters can be made, for example, of Cordierite (chemical formula (Fe,Mg) ₂Al₄Si₅0i₈^#nH₂0) , and/or Mullite (chemical formula AIgSi₂Oi_S) , and/or Aluminium Oxide Al₂θ₃, and/or Spinel

(chemical formula MgAl₂O₄) .

The filtering elements 8 can also be made in polymeric fibers, preferably in polyester synthetic fibers, possibly in foamed polyester synthetic fibers .

The filtering elements 8 could also be impregnated with actived carbon.

The filtering elements 8 can comprises a polyester synthetic fiber, possibly a foamed polyester synthetic fiber, and impregnated with actived carbon, with a thickness comprised between about 0,2 mm and 200mm, a mass per surface unit comprised between about 10 g/m² and 900 g/m².

In use, the filtering material of the filtering elements 8 is traversed at a velocity comprised between about 0,05 m/s and about 2,0 m/s. The value of the effective velocity at which the air to be treated traverse the filtering elements 8 can be chosen, by suitably varying the functioning velocity of the air moving means 7. The filtering elements 8 have a nominal flow rate comprised between about 0,100 m³/s and about 900 m³/s.

The filtering elements 8 have an efficiency of absorption comprised between a minimum of about 75% of benzene (CeH₆) , calculated over a concentration of 160000 μg/Nmc, and a maximum of about 97% of benzene (C₆H₆) , calculated over a concentration of 150 μg/Nmc.

As filtering elements 8 can be used filters classified according to EN 779 standard between Gl and G4, or correspondingly between EUl a EU4 according to the standard Eurovent, that have a flow resistance, considered when the filters works with a flow rate that is equal to the 100% of the nominal flow rate, comprised between about 1 Pa and about 250 Pa.

As filtering elements 8 can also be used filters classified according to EN 779 standard between F5 and F9, or correspondingly between EU5 a EU9 according to the standard Eurovent, that have a flow resistance, considered when the filters works with a flow rate that is equal to the 100% of the nominal flow rate, comprised between about 1 Pa and about 450 Pa. As filtering elements 8 can also be used filters obtained by other different polymeric fibers, for example polyester, thermo-fixed polyester, polyurethane, foamed polyurethane . As filtering elements 8 can be also provided bag filters, rotary filters, and/or cup filters, and/or a paper filters, all these kind of filters may be impregnated with actived carbon, or may be also filled up with actived carbon. The further lighting sources 6 are provided inside the lighting means 1 between the further filter 11 with bactericide action and the filter for gas 12 and may possibly be enclosed within a housing 14 shaped so as not to interrupt the flow of air inside the lighting means 1 and provided with respective walls 14A to which particles 15 of titanium dioxide in the form of Anatase having a photocatalytic function are applied. In general, all the internal surfaces of the lighting means 1 that may come into contact with the air flow, and above all those that are reached by the radiation emitted by the further lighting sources 6, and furthermore the lighting means an/or the lighting sources 6 themselves can be used as a substrate for applying particles of titanium dioxide. Thus also without a housing 14, the lighting means 1 is provided near further lighting means 6 with titanium dioxide in the form of Anatase that, when activated by the lighting of further lighting sources 6, performs a photocatalytic action. In particular, within the housing 14 walls and/or baffles 141 may be provided, shaped so as not to interrupt the flow of air inside the lighting means 1, but possibly to modify it to increase the residence time of the air inside the lighting means and, consequently, the purification of the air, the particles 15 of titanium dioxide are applied to the walls and/or baffles in the form of Anatase to improve the photocatalytic properties of the lighting means 1. Furthermore, also the external surface of the second chamber means 200A in which the lighting source means 3 is inserted, and in particular the external surface 200B of the second chamber means 200A facing the environment to be illuminated, is made of transparent material, and can be coated with particles of titanium dioxide in the form of Anatase, in order to make it self-cleaning. The substrates chosen for receiving the particles of titanium dioxide in the form of Anatase can be coated, before applying titanium dioxide in the form of Anatase, with titanium dioxide in the form Rutile and/or with the primer previously described, so as to enhance the adhesion of titanium dioxide in the form of Anatase to the substrate and to protect the substrate itself.

In other words, before applying layer means having photocatalytic properties (in titanium dioxide in the form of Anatase) can be provided for applying further layer means (in titanium dioxide in the form of Rutile) and still further layer means (the primer solution better described in the following) .

In operation, the air is sucked by the fan 7, enters inside the walls 2 through the first opening 2A, and is successively filtered by the prefilter 9 that retains the particulate of larger dimensions and then by the filter 10 that retains the particulate of smaller dimensions, by the further filter 11 with bactericide action, that eliminates any bacteria, and then goes inside the housing 14 in which the titanium activated by operation of the further lighting sources 6 actuates the desired photocatalytic reactions disclosed in greater detail below, for purifying the air from harmful organic and inorganic substances, both in gaseous form and from particulate that has escaped from the filter 10, the HEPA® filter, from bacteria, from mildews, from microbes that are broken down into the corresponding oxidised non- harmful compounds .

Possibly, the oxidisation compounds obtained can be broken down further or be retained by the filter of the gases 12 and/or by the still further filter 13, both of which are located downstream of the housing 14.

The lighting means 1 can furthermore be provided with a LED that reports the non-operation of the further lighting source

6.

Other LEDs may be furthermore present that indicate the need to replace one or more air treatment means 5 provided in the lighting means 1. With reference to Figures 12, 13, and 14, it is shown a lamp 300 comprising the lighting means according to the invention, and in particular the lighting means 1 of Figures 1, 3, 4. The lighting means 1 are inserted in suitable containing means 301, so shaped as to obtain a lamp 300 having a desired design, and suitable for being used in a desired environment and with desired functions.

Containing means 301 comprises a first portion 301' acting as containing body 302, cylindrically shaped, arranged for containing the lighting means 1, and provided with fixing means 303 that cooperates with further fixing means provided in lighting means 1 for fixing the lighting means 1 to the containing body 302. Containing means 301, furthermore comprises covering means 305 arranged for covering the lighting means 1, and base means 306 that in use lies on a surface on which the lamp is positioned, for example a floor.

The base means is provided with grid means 307, allowing the passage of the air, that therefore traverse the lighting means .

The grid means filters the air sucked by the fan of the lighting means 1 and prevent dust and/or other impurities to traverse the lighting means, so avoiding obstructions of the filtering elements and enhancing the efficiency of the lighting means 1.

The air by the fan of the lighting means 1 flows into the lamp 300 in the direction indicated by the arrows in Figure

12.

For example, the lamp 300 can be used as standing lamp. Inside the containing means 301 can be further provided a light source 308, for example a neon lamp 309 arranged for emitting light in the visible field.

The containing means 301 further comprises a further portion 301'' preferably in transparent material arranged for allowing the light emitted by the neon lamp 309 to diffuse in the environment in which the lamp 300 is provided. With reference to Figure 2, 6, 7, there is shown a second embodiment of the lighting means 100 comprising walls 20 provided with a first opening 2OA and with a second opening 2OB arranged to enable the entry of air from the external environment inside the space enclosed by the walls 20, a first wall 2OC and a second wall 2OD shaped so as to define chamber means 2OE in said lighting means 1, lighting source means 30 for lighting an environment in which the lighting means 1 is located, constituted, for example, by one or more lighting sources 40 for emitting radiation into the visible field, that may be of any known type, for example fluorescent lamps, incandescent lamps, halogen lamps, etc., and air treatment means 50 for treating the air present within the walls 20. The lighting source means 30 and the air treatment means 50 are inserted inside the chamber means 2OE, in particular, the second wall 2OD, positioned so as to be interposed between the lighting source means 30 and a zone to be lighted, being shaped so as not to hinder but to enhance the lighting of the lighting source means 30, the second wall 2OD being for example made of glass or another suitable material. The air treatment means 50 may comprise air moving means, for example a suction fan 70, for sucking air inside the walls 20 shaped so as to generate forced air circulation inside the lighting means 1 in the direction indicated by the arrows F' , making it enter through the first opening 2OA and making it exit through the second opening 2OB, and a plurality of filtering elements 80 arranged in succession inside the walls 20 so as to be successively traversed by the air that enters from the first opening 2OA.

In the event of a lack of air sucking means 7, the path indicated above can be followed by the air moved simply by natural convection motion. The filtering elements 80 comprise in succession a prefilter 90 suitable for filtering the particles of relatively large dimensions present in the sucked air, a filter 91 for the particulate of very small dimensions, for example a HEPA® filter with a desired filtering capacity, a further filter 120 that is a titanium dioxide (TiO₂) -based filter 120. For the filtering elements 80, their composition, their spatial arrangement, their characteristics, the same considerations made in reference with the embodiment of Figure 1 apply.

The lighting source means 30 is provided inside the lighting means 100 between the filter 91 and the further filter 120 and may possibly be enclosed inside a housing 140 shaped so as not to interrupt the flow of air inside the lighting means 1 and provided with respective walls 14A onto which particles 150 of titanium dioxide in the form of Anatase having a photocatalytic function are applied. Also in this case, within the housing 140 baffles or walls can be provided that are arranged for receiving the particles of titanium dioxide, in this way the surface of the lighting means active for photocatalysis is increased, thus increasing the photocatalytic properties of the lighting means 100. Also in this case, any internal surface of the lighting means 100 preferably positioned near the lighting source means 30 can be used as a substrate for applying the particles of titanium dioxide in the form of Anatase 150 that, activated by the lighting of the lighting source means 30, performs a photocatalytic action.

The operation of this embodiment is similar to the one previously provided for the embodiment in Figure 1, and also this embodiment enables the air of an environment to be treated, eliminating any particulate, organic and inorganic harmful substances, bacteria, mildew and microbes that are decomposed in the corresponding non-harmful oxidised compounds .

In both the embodiments of the lighting means 1, 100, furthermore, connecting elements can be provided for connecting the lighting means 1, 100 to the power supply and/or further connecting means for connecting the lighting means 1 to a battery or further energy supply. In this way, it is possible to create lighting means 1 and 100 that can be connected directly to the mains supply and/or that can be connected to a battery and that can accordingly easily be carried to desired use zones and that can continue to operate even in the absence of electric power.

The installations disclosed above enable lighting elements to be created that in addition to lighting an environment in which they are installed, enable the air in such environments to be treated and in particular to be purified.

The air treatment elements provided on lighting means disclosed above, the features and the operating specifications thereof can be selected on the basis of the features of the environment in which the aforementioned lighting means have to be positioned, for obtaining lighting means that better adapt to the features of a given environment .

For the aforementioned lighting means, materials can be used that are also very different from one another to obtain design objects, lighting means that adapts to various types of decoration and that creates desired decorative effects. The lighting means according to the invention can furthermore be provided with sound emitting means that is suitable for producing a desired sound effect, such as multimedia readers, CD readers, cassette means and radio devices.

Said sound emitting means being able to operate completely independently of the lighting means .

Furthermore, the lighting means can be provided with control elements suitable for modulating the light emitted by the lighting means for suitably varying the light emitted by the lighting means in response to particular needs of a user and/or features of the environment in which such lighting means is mounted; such control means being able to be furthermore suitable for obtaining desired light plays. For this purpose said control means can also be incorporated into the emission sources 4, 40. Lamps of various types can also be created with the lighting means according to the invention, to be applied to walls, ceilings, standing lamps, ceiling light fixtures, lamps, chandeliers, wall lamps, table lamps, desk lamps, or still other things .

As previously the titanium dioxide prevalently in the form of Anatase can be applied on any suitable substrate of the lighting means 1, 100, for example on the lighting means 6 itself, on the filtering elements 8, 80, on the wall of the lighting means .

As some materials could be damaged by contact with the titanium dioxide in the form of Anatase, a further layer of titanium dioxide can be provided in the form of Rutile, interposed between such materials and the photocatalytic layer of titanium dioxide. The titanium dioxide in the form of Rutile, is photocatalytic to a very limited extent and does not attack the material and therefore furthermore has excellent adhesive properties promoting adhesion between the material and the layer of Anatase titanium dioxide. Alternatively to the titanium dioxide in the form of Rutile, other compounds can be used that are characterised by great power of adhesion to the substrate and that are not oxidisable by Anatase. In addition, before applying titanium dioxide in the form of Anatase can be provided for applying a still further layer arranged for improving the adhesion of the titanium dioxide in the form of Anatase to the particular material on which it has to be applied, for instance the ceramic of the "Honeycomb" filter, the walls of the lighting means and so on.

The still further layer means can be obtained by applying a solution, a water based binder or a solution in powder form. In a version, the solution of the still further layer means is an amorphous water solution comprising TiC>2 as peroxititanic acid between about 0,05% and 9,70% weight percent, preferably about 0,85% weight percent of TiC>2, and water for the remaining part, this solution is also known with the commercial name of Titanium K is known as the Titanium R.

In a further version, the solution of the still further layer means is a water solution comprising silica gel between about 0,05% and 19,90% weight percent, cationic surfactants between about 0,05% and 5,00% weight percent, acrylic resins between about 0,05% and 9,00% weight percent, Sodium Hydroxide between about 0,005% and 5,00% weight percent, and water for the remaining part, this solution is also known with the commercial name of Titanium R2. Preferably the solution can contain Silica Oxide, preferably in colloidal form, at about 7,5%, cationic surfactants at about 1,0%, acrylic resins at about 1,5%, Sodium Hydroxide at about 0,1%, and water at about 89,9%.

In a still further version, the solution is a crystalline water solution containing TiC>2, preferably as modified Anatase Peroxide, comprised between about 0,05% and 9,90% weight percent, preferably about 0,85% weight percent, and water for the remaining part; this solution is known with the commercial name of Titanium K.

In a still further version, the solution is a water solution obtained by mixing Titanium K and Titanium R, i.e. by mixing about 70% a solution of modified Anatase Peroxide and about 30% of Peroxititanic acid. This solution contains TiC>2 between about 0,05% and 9,90% weight percent, preferably about 0,85% weight percent, and water for the remaining part, and it is also known with the commercial name of titanium KR. In a still further version, the solution is a water solution obtained by mixing about 70% a solution of modified Anatase Peroxide, and about 30% of Peroxititanic acid and Silver Acetate C2H₃AgC>2 present in weight percentage comprised between about 0,1% and 0,009%. The solution contains TiC>2 between about 0,05% and 9,90% weight percent, preferably about 0,85% weight percent and water for the remaining part, and it is also known with the commercial name of Titanium

KR-VB .

In a still further version, the solution is a water solution containing TiC>2 Degussa P25, comprising about 80% of Titanium as Anatase and about 20% of Titanium as Rutile, between about 0,05% and 9,50% weight percent, preferably about 3,0% weight percent and water for the remaining part.

This solution is also known with the commercial name of

Titanium β . It is hereinafter described the process for preparing the solution of Titanium β as non-limitative example for possible procedure for preparing the solution of the still further layer means .

A solution containing distilled demineralised water and a weight percentage of about 2,00% of Titanium Degussa P25

(containing 80% of Titanium in Anatase form and 20% of

Titanium in Rutile form) it is prepared.

Then the water solution is heated, by using a magnetic stirrer, to about 4O⁰C - 6O⁰C, and when the desired temperature is reached, TiC>2 powder is added paying attention not to create clots .

The solution obtained is then sonicated, i.e. it treated with high-frequency sound waves to disrupt the TiC>2 particles in the solution, in order to diminishing the dimensions of the particles and to obtaining a solution with particles having homogeneous dimensions.

The sonication process can last between about 5 to about 30 min, in order to completely homogenizing the solution.

It is hereinafter described the process for preparing a desired support, for example one of the filters of the filtering elements 8, 80, for example the filters 11, 12 of the "honeycomb" type .

The "primer" is sprayed on the filter, for example with a spray gun, so as to cover with the "primer" based for example on colloid silica, in this case the "primer" known as Titanium R2, the surface of the filter. The primer is applied so as to have a superficial density of about 30 g/m².

Therefore the filter is heated to about 8O⁰C for about 30 min in a muffle, so as to speed up the drying process. Then Titanium β is applied on the filter, so as the filter present on the filter, so as to have a superficial density of about 100 g/m² and subsequently the filter is heated to about 8O⁰C for about 30 min in a muffle, so as to speed up the drying process. The filter can also be baked to a Temperature of 400⁰C.

On filter so prepared can be applied layer means and/or further layer means. Furthermore, together with titanium dioxide, as seen, layers of material can be provided on the lamps according to the invention having special desired features, for example layers can be made in anti-microbial materials such as, for example, silver that enables the bactericide action of the lighting means to be increased, and furthermore enables such action to continue even when the radiation source is deactivated. In order to obtain the air treatment means, special solutions can furthermore be used containing, in addition to the titanium dioxide in the form of Anatase, other oxidising or bactericide agents, or with other specific functions in order to reinforce the antibacterial, anti-mildew, air-purifying and surface-protection properties of the titanium dioxide.

In particular, using the following is also provide for: silver acetate, sodium hydroxide, sodium nitrite, heptahydrate sodium sulphite, pentahydrate sodium thiosulphite, lithium oxide and silicon. The titanium oxide TiC>2 can be obtained form many possible sources and in many method, for example those precedently described.

Titanium oxide, TiC>2, can also be obtained with electrochemical methods, for example by oxidising a metallic surface containing metallic titanium. The peculiar feature of the lighting means disclosed above mainly consists of the use of titanium dioxide. Titanium dioxide is a semiconductor material that absorbs electromagnetic radiation, in particular solar radiation or radiation emitted by a luminous lamp or by a U.V. lamp, and if this energy is greater than the energy difference between the valence band with a lower energy content and the conduction band, titanium dioxide is excited. As a result, the excited electron is promoted by the valence band to the conduction band, generating an excess of electronic load (e^~) in the conduction band and an electron gap (h⁺) in the valence band: TiO₂ + hv -^ h⁺ + e^". These pairs of electrons and electron gaps interact with molecules present in the environment that surrounds them, in particular the electrons can reduce substances that are electron acceptors, whilst the electrons gaps can oxidise the molecules of an electrons donor, as exemplified in the reaction patterns below. D + h^{+ ■}* D^{» +}; A + e^{" ■}* A^{» +} .

The electron gaps, have an oxidising power that is so high as to be able to oxidise most of the organic contaminants, they can, for example, react with a molecule of water, generating a highly reactive hydroxyl radical and a hydrogen radical whereas the electrons have a very high reductive power and can react with an oxygen atom to form an oxygen anion or superoxide ion (O₂-) , as shown in the reaction pattern below H₂O + h^{+ ■}* 0H» + H⁺; O₂ + e^{" ■}* 0₂»^"

The titanium dioxide crystallizes in the forms Anatase, Rutile, or brookite, of these, the Anatase form is the one that is the most photocatalytically active and has an energy- value between the valence band and the conduction band of 3.2eV, i.e. if this material is irradiated with photons having energy of >3.2eV, i.e. with a wave length of about 388 nm, an electron is promoted in the conduction band and so the oxidoreduction reactions can be triggered by the electron and by the electronic gap.

The energy value of the band distance is such that the titanium dioxide in the form of Anatase can perform the activity of a catalyst of oxidation-reduction reactions when it is reached by solar radiation or also by artificial radiation of a normal lamp, or also of a U.V. lamp. Furthermore, such a catalyst activity is performed in rather variable temperature conditions and occurs easily around ambient temperature values .

The photocatalytic activity is also performed even when the titanium dioxide is in the other two aforementioned forms of crystallisation, although with less effectiveness than in the Anatase form, the energy difference between the valence band and the conduction band being greater than 3.2eV for these forms .

Titanium dioxide enables most of the organic and inorganic pollutants present in both the air and the water to be oxidised by taking them to the maximum degree of oxidisation, in particular the organic compounds are oxidised to carbon dioxide (CO2) and water (H₂O) , the nitrogen compounds to nitrate ions (NC>₃^~) , the sulphur compounds to sulphate ions (SO₄^2") . Furthermore, many harmful gases or substances such as thiols, mercaptans, formaldehyde, that are decomposed by the titanium dioxide, are also stinking, so the decomposition thereof also eliminates the problem of bad smells. The titanium dioxide furthermore performs a very effective anti-microbial, anti-bacterial and anti-mildew action, as unlike other anti-bacterial agents it does not kill the bacterial or the pollutants but through oxidation-reduction reactions it decomposes them into gaseous substances that are dispersed into the surrounding environment, not accumulating on the catalyst. This furthermore enables the photocatalytic activity of the titanium dioxide to remain unaltered over time. In particular, the bacteria are decomposed by means of the hydroxide radicals (0H» ) and the oxygen anions (C>2^~) generated by the photocatalytic process that attacks the lipid membrane of the bacteria, decomposing it and preventing the aerobic respiration phase of the bacteria.

The microorganisms thus die and are then gradually decomposed until carbon dioxide and water are obtained, that are released into the surrounding environment.

The destruction of the mildews, bacteria, viruses and the other microorganisms, enables the bad smells to be eliminated that are associated with the presence thereof, and enables high hygienic conditions to be maintained in the environment in which the lamps provided with a layer of titanium are located.

The different behaviour of the Rutile titanium dioxide compared with Anatase titanium dioxide is due to the different quantity of energy required to excite an electron from the valence band to the conduction band of these two forms: 388 nm for Anatase and 413 nm for Rutile, and by the different reducing/oxidising power respectively of the excited electron and of the electronic gap generated, that is high for Anatase and low for Rutile. The titanium dioxide formulations that can be used to be applied to a substrate that it is desired to make photocatalytically active are various, preferably the titanium dioxide as said, being in the form of Anatase in such formulations rather than in Rutile. In particular, a water solution can be used containing about 0.85% of TiC>2, 70% in the form of Anatase and the remaining 30% in the form of Rutile, that is dispersed in a substrate by atomisation, using for example an aerograph, a spray gun. In fact some substrates such as, for example the vitreous substrates, have hydroxide groups, also in significant concentrations, that bond with the structures of the titanium dioxide, with an expulsion reaction of a water molecule, promoting effective adhesion of the titanium dioxide to the substrate .

If titanium dioxide has to be applied to a substrate that is not particularly suitable for receiving it, it is possible to interpose between the substrate and the particles of titanium dioxide an intermediate layer that enables the reactions seen above to be achieved with the titanium dioxide, and which bonds in a durable manner with the substrate used. The lighting means disclosed above can be subjected to different modifications that enable them to be adapted to specific features in an environment in which it is desired to position such lighting means. With the lighting means disclosed above ceiling lamps, wall lamps, lamps also with various and complex forms and side- reading lamps, lamps for the home or also for the office, or lamps suitable for industrial environments and public premises can be created. Many experiments have been conducted for testing the functioning of the lighting means 1, 100, according to the invention, using the testing apparatus 300 of Figure 5. The testing apparatus 300 comprises a reaction chamber B, inside which a lighting means 1, or 100 it is positioned, a mixing chamber A, inside which air is mixed with the NO_x coming from the input line E, a pump P arranged for moving the gas mixture, air and NO_x, through the testing apparatus 300, and an analyser C, namely the Nitrogen Oxides Analyser Mod. 8440, produced by Monitor Labs., arranged for analyse the NO_x content in the gas mixture coming through it. The testing apparatus 300 further comprises pipes 302, 303, in polytetrafluoroethylene (PET) , a material that do not alters the concentration of NO_x, for connecting the parts of the apparatus and thus allowing the circulation of the NO_x air mixture across it. As reaction chamber B, can be used a box in Plexiglas having an internal volume of about 157 liter, inside which can be positioned lighting means according to the invention both according the first embodiment and according the second embodiment .

The lighting means used comprises two filter in polyester and two filters with Titanium Oxide particles, i.e. two filters having photocatalytical properties, but it can be also provided with four filters with photocatalytical properties . The lighting means is crossed by a gas mixture moved by the pump P with a nominal flow rate of 180 m³/h and an effective flow rate of 153 m³/h.

The lighting means according to the first embodiment is provided with a further lighting sources irradiating into the UV-A field, namely between a wave length 360 to 420nm. In the testing the NO_x are introduced in the apparatus at the input line E, mixed with air in the mixing chamber A, and moved from the notch 301, firstly through the pipe 302 so as to traverse the analyser C, in which the original content of NO_x in the mixture is analysed. In subsequent experiments the air NO_x mixture is moved from the notch 301 through the further pipe 303 so as to traverse the reaction chamber B and then through the still further pipe 304 through the analyser C in which the content of NO_x in the mixture after the passage through the reaction chamber B is analysed. The first measurements show an original content of NO_x in the mixture of about 0.6 ppm.

The measurements have been firstly repeated after the NO_x air mixture had traversed the reaction chamber into which the lighting means were not functioning, so as to evaluate the possible decrease of the NO_x in the mixture due to the adsorption.

The results of these measurements are shown in Figures 6-8, in the curve obtained with light results, it is removed due to adsorption about 10% of NO, 30% of NO₂ and then 20% of NO_x due to adsorption over about 60 min. Subsequently the measurements with the analyser C have been repeated after the NO_x air mixture had traversed the reaction chamber B into which the lighting means were functioning, so as to evaluate the decrease of the NO_x in the mixture due to the photocatalytical properties of the lighting means .

The results of the measurements obtained inserting a lighting means according to the first embodiment of the invention there are shown in Figures 9-11: about 100% of NO it is removed within 3 minutes, about 70% of NO2 it is removed within 15 minutes, therefore about 90% of NO_x it is removed within 15 minutes.

As can be seen from the graph of figure 9, about 80% of the NO_x it is removed within 7 minutes. The lighting means according to the invention is, therefore very effective in removing harmful gases from the treated air, and this removal happens very fast.

Figures 9-11, and in particular the data of the curve obtained with dark results show that, after a first functioning, the lighting means, maintain a certain efficacy in gas treatment and in particular in NO_x removing also when the lighting sources 3 and/or the further lighting source 6 is switched off.

In other words, after the first functioning of the lighting means according to the invention, a certain photocatalytic property remain and thus a certain treatment of the gases traversing the lighting means is still possible. As can be seen from the graph of figure 9, about 80% of the NO_x it is removed within 7 minutes. The lighting means according to the second embodiment is provided with a lighting source irradiating into the visible field and activating the photocatalytic material. At the beginning a gas mixture, namely cigarettes' smoke has been fed to the testing apparatus, for evaluating the initial decay of the NO_x contained in the smoke. The smoke fed to the testing apparatus contains about 414,2 ppb of NO, about 434,0 ppb of NO_x, about 19,8 ppb of NO₂. As can be seen from the graph of Figure 15 a certain decreasing of the concentration of NO_x occurs.

This is due probably to the absorption of the NO_x and in particular of NO on the substrates of the testing apparatus and of the lighting means. A transformation of NO into NO₂, can be excluded, since the concentration of NO2 does not increase .

A certain absorption by the Tiθ2 present in the lighting means can also occur. Thereafter the testing apparatus is fed with the gas mixture having about the same composition of cigarettes' smoke, namely containing about 477,6 ppb of NO, about 494,5 ppb of NO_x, about 16,9 ppb of NO2, and in correspondence of the point Z of Figure 16, the lighting means 100 has been switched on. The measurements have been firstly repeated after the NO_x air mixture had traversed the reaction chamber into which the lighting means were not functioning, so as to evaluate the possible decrease of the NO_x in the mixture due to the adsorption. The results made on the gas mixture obtained at the output of the lighting means, are shown in Figure 16, about 90% of NO_x and about 100% of NO are removed.

The results show the high efficiency of the lighting means according both the first and the second embodiment of the invention, in decreasing the NO_x content in the air traversing the lighting means.

One of the possible reaction mechanism for converting NO to nitrate ion (NO₃^") , provide the reaction of NO with superoxide ion (O₂*) obtained from the reduction of the oxygen of the air promoted by the electrons of the valence band of the TiO₂, as illustrated by the following reactions scheme: O₂ + e^" -^ O₂'^" NO + 0₂»^{" ■}* NO₃^" According to this hypothesis the reaction kinetic of the reaction decay of the NO could be a pseudo-first order reaction regulated by the following law: ln[NO]_t/[NO]o=k*t where [NO]_t represents the concentration of NO at time t, [NOJo represents the starting concentration of NO, k represent the parameter of the pseudo-first reactions comprehensive of the (02*^~) concentration values.

This hypothesis seems to be validated by the linear behaviour of the In[NOJt/ [NO]₀ rate over time.

The value of the parameter k obtained form the above described experiments suggest that by suitably dimensioning and shaping the lighting means, it is possible to vary the decay time of the NO_x, independently from the initial concentration of the NO_x in the air mixture treated with the lighting means, thus obtaining lighting means with a great efficacy in decreasing, or removing NO_x from air. Experiments similar to the above described ones, have been conducted to evaluate the bactericidal efficacy of the lighting means according to the invention. For these experiments a testing apparatus analogous to the apparatus above described has been used. Lighting means comprising a lighting source of the UV-A kind, interposed between two filters provided with a "honeycomb" ceramic support lOOCSI, and with a layer of Titanium Oxide, have been introduced into the Reaction chamber B. The Reaction Chamber is further provided with two Agar Petri dishes situated at different points of the smoking chamber that are suitable supports for the growing the Escherica CoIi.

Known quantities of Escherica CoIi that had been already grown up on a suitable culture soil LB, have been sprayed into the reaction chamber B, subsequently, the testing apparatus and the lighting sources has been switched on: lighting source has been switched on so as to irradiate and the air moving means, a fan, has been switched on to make the air to circulate through the testing apparatus . The flowing air drags the bacteria present in the reaction chamber making them to circulate into the reaction chamber B and to traverse the lighting means and the filters . After a treatment period of time, the air mixture, possibly containing bacteria, has been analysed by the analyser C and the results obtained are shown in table 1.

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Table 1

As can be seen from the table the filters containing TiC&gt;2 have a great efficacy in removing the bacteria from the air, after 9 hours 100% of the bacteria have been removed, and the filter functions also in dark condition, column 3 of the table 1, in fact, after 9 hours about 39% of the bacteria have been removed.