Abstract: The invention relates to a composition comprising mica and glass, said glass comprising: 10 to 30 mol % of SiO2 5 to 40 mol % of BaO 15 to 30 mol % of B2O3, the sum of the concentrations of zinc oxide, alkali metal oxide and alkaline earth oxide in the glass extending from 15 to 65 mol %. This composition is intended to be molded at a temperature above the Tg of the glass so as to form composite parts that can serve as an electrical insulator.

Abstract: The invention relates to a filtering media having a photocatalytic action which has a thickness of at least 2 mm, which is homogeneous and which is devoid of orifice apparent to the naked eye, comprising a felt of inorganic fibers, the fibers of which are coated with a coating comprising a catalyst having a photocatalytic action, said felt exhibiting a weight per unit area of between 30 and 80 g/m2, said coating representing 5 to 80% of the weight of said media, said media exhibiting a gas pressure drop of less than 150 Pa at 1 m/s in unpleated condition. This media is intended to be incorporated in a purifier of gas, such as air, furthermore comprising a system for illuminating said media with UV radiation. The media exhibits an excellent purification efficiency and a very low pressure drop.

Abstract: The invention relates to an arc melted silica crucible having a polygonal opening, in particular square or rectangular, and its method of fabrication, which comprises preforming the silica powder in a hollow mold having a polygonal opening, said mold being provided with a multiplicity of channels passing through its bottom and its walls, said channels being distributed over its whole internal surface, to constitute a preform, then melting the silica by an electric arc inside the preform, sucking the gases through the mold and the preform, generating a gas speed of at least 0.15 m/second at every point of the inner surface of the preform at the onset of the melting.

Abstract: The invention relates to a method and a device for the purification of air by passing a flow of the air through a filter having a photocatalytic action subjected to UV lighting, said filter comprising a felt of mineral fibers, the fibers of which are coated with a material having a photocatalytic action, the residence time of the air in contact with the filter being greater than 70 msec and the UV lighting having a power of less than 35 mW per cm2 of lit surface of filter having a photocatalytic action. The invention is particularly effective in removing volatile organic compounds from the air.

Abstract: The invention relates to a composition comprising mica and glass, said glass comprising: 10 to 30 mol % of SiO2 5 to 40 mol % of BaO 15 to 30 mol % of B2O3, the sum of the concentrations of zinc oxide, alkali metal oxide and alkaline earth oxide in the glass extending from 15 to 65 mol %. This composition is intended to be molded at a temperature above the Tg of the glass so as to form composite parts that can serve as an electrical insulator.

Abstract: The invention relates to a filtering media having a photocatalytic action which has a thickness of at least 2 mm, which is homogeneous and which is devoid of orifice apparent to the naked eye, comprising a felt of inorganic fibers, the fibers of which are coated with a coating comprising a catalyst having a photocatalytic action, said felt exhibiting a weight per unit area of between 30 and 80 g/m2, said coating representing 5 to 80% of the weight of said media, said media exhibiting a gas pressure drop of less than 150 Pa at 1 m/s in unpleated condition. This media is intended to be incorporated in a purifier of gas, such as air, furthermore comprising a system for illuminating said media with UV radiation. The media exhibits an excellent purification efficiency and a very low pressure drop.

Abstract: The present invention relates to a gas purifier containing a filtering media having a photocatalytic action, a system for illuminating said media with UV radiation, a time-delay means or a volatile organic compound analyzer, and a means for automatically adjusting the speed of the gas passing through the media or for adjusting the intensity of the UV illumination, said adjusting being carried out as a function of the time determined by the time-delay means or as a function of the content of a volatile organic compound analyzed by the analyzer.

Abstract: The invention relates to a particulate filter comprising a cartridge and a filter media placed in the cartridge in the prefiltering position, said filter media being essentially mineral. Thanks to the absence of any organic compound, the filter media generates no volatile organic compound. The filter media may also be of the type having a photocatalytic action.

Abstract: The invention relates to a gas purifier comprising a filtering media having a photocatalytic action, a system for illuminating said media with UV radiation, a time-delay means or a volatile organic compound analyzer, and a means for automatically adjusting the speed of the gas passing through it or for adjusting the intensity of the UV illumination, said adjusting being carried out as a function of the time determined by the time-delay means or as a function of the content of a volatile organic compound analyzed by the analyzer. The invention also relates to a process for the purification of gas using a purifier comprising a filtering media having a photocatalytic action and a system for illuminating said media with UV radiation, according to which, when the concentration of a compound in the gas is greater than a value V1, the operating capacity of the purifier is lower than its capacity when the concentration of the compound in the gas is less than the value V2, V2 being less than or equal to V1.

Abstract: The invention relates to a silica yarn and to woven or nonwoven fabrics produced from said yarn, which comprises 30 to 1500 ppm by weight of aluminum and 10 to 200 ppm by weight of titanium in oxidized form, the sum of the mass of the chemical elements different from Si and O being less than 5000 ppm by weight, the following elements being absent or present in a very small quantity: boron, sodium, calcium, potassium and lithium. The fabrics comprising this silica yarn have an excellent high-temperature withstand and thus retain their flexibility for a long time at above 600° C. They are useful especially in uses requiring good high-temperature flexibility, such as for furnace seals.