INSTALLATION AND METHOD FOR PRODUCTION OF NANODISPERSED POWDERS IN MICROWAVE PLASMA Russian patent published in 2005 - IPC

FIELD: production of nanodispersed powders of refractory inorganic materials and compounds, in particular, installations and methods for realization of plasmochemical processes of production of nanodispersed powder products.

SUBSTANCE: the installation comprises production-linked: microwave oscillator 1, microwave plasmatron 2, gas-flow former 3, discharge chamber 4, microwave radiation absorber 5, reaction chamber 6, heat-exchanger 7, filter-collector of target product (powder) 8, device for injection of the source reagents in a powdered or vapors state into the reaction chamber, the installation has in addition a device for injection of the source reagents in the liquid-drop state, it has interconnected proportioner 9 in the form of cylinder 10, piston 11 with gear-screwed electric drive mechanism 12 adjusting the speed of motion of piston 1, evaporative chamber 13 with a temperature-controlled body for regulating the temperature inside the chamber that is coupled to the assembly of injection of reagents 14 in the vaporous state and to the assembly of injection of reagents 15 in the liquid-drop state, injection assembly 14 is made with 6 to 12 holes opening in the space of the reaction chamber at an angle of 45 to 60 deg to the axis of the chamber consisting at least of two sections, the first of which is connected by upper flange 16 to the assemblies of injection of reagents, to discharge chamber 4, plasmatron 2, with valve 17 installed between it and microwave oscillator 1, and by lower flange 18, through the subsequent sections, it is connected to heat exchanger 7, the reaction chamber has inner water-cooled insert 20 rotated by electric motor 19 and metal scraper 21 located along it for cutting the precipitations of powder of the target product formed on the walls of the reaction chamber, and heat exchanger 7 is made two water-cooled coaxial cylinders 22 and 23, whose axes are perpendicular to the axis of the reaction chamber and installed with a clearance for passage of the cooled flow, and knife 24 located in the clearance, rotating about the axis of the cylinders and cleaning the working surfaces of the cylinders of the overgrowing with powder, powder filter-collector 8 having inside it filtering hose 25 of chemically and thermally stable material, on which precipitation of powder of the target product from the gas flow takes place, in the upper part it is connected by flange 26 to the heat exchanger, and in the lower part the filter is provided it device 27 for periodic cleaning of the material by its deformation, and device 28 with valve 29 for sealing the inner space of the filter. The method for production of nanodispersed powders in microwave plasma with the use of the claimed installation consists in injection of the source reagents in the flow of plasma-forming gas of the reaction chamber, plasmochemical synthesis of reagents, cooling of the target product and its separation from the reaction chamber through the filter-collector, the source reagents are injected into the flow of plasma-forming gas, having a medium-mass temperature of 1200 to 3200 K in any state of aggregation: vaporous, powdered, liquid-drop or in any combination of them, reagents in the powdered state are injected in the form of aerosol with the gas-carrier into the reaction chamber through injection assembly 35 with a hole opening into the space of the reaction chamber at an angle of 45 to 60 deg to the chamber axis, reagents in the liquid-drop or vaporous state are injected into the reaction chamber through injection assemblies 15 or 14, respectively, in the form of ring-shaped headers, the last of which is made with 6 to 12 holes opening into the space of the reaction chamber at an angle of 45 to 60 deg to the chamber axis, each of them is blown off by the accompanying gas flow through the coaxial ducts around the holes, at expenditure of the source reagents, plasma-forming gas, specific power of microwave radiation, length of the reaction zone providing for production of a composite system and individual substances with preset properties, chemical, phase composition and dispersity.

EFFECT: universality of the industrial installation, enhanced capacity of it and enhanced duration of continuous operation, as well as enhanced yield of nanodispersed powders and expanded production potentialities of the method.

20 cl, 1 dwg, 4 ex