Abstract: Capacitive electrical heating of a fluidized bed enables the individual solid particles within the bed to constitute the hottest portion thereof. This effect is achieved by applying an A. C. voltage potential between dielectric coated electrodes, one of which is advantageously the wall of the fluidized bed rejection zone, sufficient to create electrical currents in said particles so as to dissipate heat therein. In the decomposition of silane or halosilanes in a fluidized bed reaction zone, such heating enhances the desired deposition of silicon product on the surface of the seed particles within the fluidized bed and minimizes undesired coating of silicon on the wall of the reaction zone and the homogeneous formation of fine silicon powder within said zone.

Abstract: Fuel, fertile material and/or absorber material containing particles for fuel and/or absorber elements in nuclear reactors are coated by a process comprising introducing thermally cleavable gases in the reaction space heated to above 1000.degree. C. of a fluidized bed unit with the help of a gas inlet nozzle cooled with a cooling medium and having an elongated inlet tube, decomposiing the cleavable gases after leaving the nozzle, depositing the decomposition products on fuel, fertile material or absorber particles present in the fluidized bed and bringing these coated particles into fuel elements or absorber elements. The cooling medium is solely gaseous and only the portion of the inlet tube for the nozzle tips of the gas inlet nozzles within the axis are cooled and the heat glow penetrating from outside is reduced by heat insulation. An apparatus for carrying out the process is also described.

Abstract: In a fluidized bed reactor total gas feed is through a constricted opening at the bottom of the reactor. A carrier gas supply duct communicates with said bottom. A reaction gas supply tube, disposed within said duct, has an outlet spaced from said bottom and is comprised of a bundle of tubes arranged to dispense an annular stream.

Abstract: One shot coating of powdered material with a metal film is achieved by allowing the material to fall through a vertical refractory cylinder, the inside of which is covered with the metal. The process takes place in a vacuum chamber and the cylinder is heated to evaporate the metal onto the falling material as it passes through the cylinder.

Abstract: Apparatus for suspending particles in a fluidized bed within a coating chamber where the particles are coated with a substance contained in a reactant gas introduced into the chamber by means of a centrally arranged nozzle extending upwardly from the coating chamber floor. Levitating gas for suspending the particles in the fluidized bed is introduced into the chamber from around the centrally arranged nozzle and generally parallel with the chamber base to promote particle circulation through the fluidized bed and minimize deposition within the chamber in one species of the apparatus, the nozzle is supported upon a movable probe which forms a closure for an opening in the chamber base through which coated particles are unloaded.