Abstract: A method for purifying a silicon-based load to obtain extra-pure silicon, includes: a) directing a plasma jet from an initial non-transferred arc torch onto a solid wall of a volume having an outlet to generate a homogeneous plasma flow, b) continuously injecting a silicon-based load having particles and/or grains, or crushed, into the homogeneous plasma flow to obtain an assembly, c) continuously directing the assembly from the outlet towards a melting pot having heating elements and stirring the crushed load into a molten state, d) once the entire crushed load has been injected and a molten bath formed inside the melting pot, directing the plasma jet from at least a second non-transferred arc torch onto the surface of the bath, e) removing the slag on the surface of the bath, and possibly repeating steps d) and e) to volatilize some of the bath impurities brought to the surface due to stirring.

Abstract: The present invention relates to a vitrification process for a pulverulent material and an apparatus for implementing said process. The process consists in introducing the pulverulent material into the fusion area of a furnace via injection means, where it is melted by means of at least one plasma torch to obtain a melt, and where the melt is removed from the furnace via a casting zone, the material being introduced laterally into the fusion zone in a direction comprising a horizontal component, and the melt being removed from the furnace by overflowing via the said casting zone, more or less along said horizontal component and away from the means for injecting the material into the furnace, in relation to the fusion zone.

Abstract: DC arc plasma torch, in particular intended for obtaining a chemical substance from a plasma-generating gas (P) which includes said substance.According to the invention:the electrode (2A) is in communication with the chamber (3) for injecting the plasma-generating gas via a tubular piece (2B) through which the arc (10) passes and which constitutes the reaction chamber in which said plasma-generating gas (P) gives rise to the plasma (13) under the action of the electric arc (10); andmeans (7, 8) are provided which make it possible to form a fluid barrier (14) between the electrode (2A) and the plasma (13).

Abstract: The present invention concerns a plasma torch of the type including:two tubular and axially spaced coaxial electrodes (5 and 6), each electrode being arranged in a support (3 and 4) in which a cooling circuit (8 and 9) of the corresponding electrode is fitted; anda passageway for injecting a plasmagene gas between said electrodes, said passageway including a revolution piece (17) coaxial with said electrodes and defining with the latter and their supports a chamber (18) into which the plasmagene gas is injected via transverse orifices (17B) provided in the piece.According to the invention, the revolution piece (17) is not provided with internal cooling means.

Abstract: A plasma torch includes two tubular coaxial electrodes, at least one of which is axially movable between an operating position in which the movable electrode is spaced from the other electrode and an initiating position in which the movable electrode is in contact with the other electrode, thus establishing an electric short circuit so as to generate an electric arc upon rupture of the electric short circuit hen the mobile electrode is brought back to its operating position. Each electrode is contained in a support provided with a cooling circuit, through which a cooling fluid circulates. The cooling circuit associated with the movable electrode is provided with a seal which permits the electrode to be moved without creating any leaks in the cooling circuit.

Abstract: A plasma torch includes two axially spaced tubular electrodes and an electromagnetic coil for rotating an electric arc formed between the electrodes. Each electrode is held in a support, at least one support containing a cylindrical cooling chamber through which an electrically nonconductive cooling fluid can be passed. The electromagnetic coil divides the cooling chamber into two annular spaces which are interconnected at one end.

Abstract: This invention relates to a process and device for injecting at least one stream of a fluid matter into a hot gaseous flow, such as a plasma jet. According to the invention, said hot gaseous flow has the shape of an envelope of revolution communicated thereto, and the nozzle for injection of the stream of fluid matter is dispsoed coaxially to the axis (X--X) of said envelope of revolution. The invention is more particularly applicable to plasma chemistry.

Abstract: This invention relates to a plasma torch and a first and second electrode for use in a plasma torch. Each electrode includes a tubular intermediate part which is intended to come into contact with the arc feet and a pair of end parts which are intended to facilitate connection of the electrode to the other parts of the torch. Each electrode is disposed within an enclosed fluid circulation chamber within which a cooling fluid circulates. The intermediate and end parts of each electrode are at least ten millimeters thick. The individual parts of each electrode are connected together by a moisture-impervious, disassemblable, mechanical assembly which prevents the cooling fluid from coming in contact with the interior of the electrodes.

Abstract: The invention concerns plasma torches comprising an upstream electrode (12), a downstream electrode (11), a chamber (15) for the injection of plasma producing gas, a priming electrode (13) and optionally a magnetic field coil (14), in which the upstream root of the arc is displaced on the upstream electrode. According to the invention, in order to control a continuous or reciprocating and/or an oscillatory translation, the field coil is supplied with a variable direct current, if need be a pulsatory undulatory current, and/or a diffuser is placed at the inner end of the upstream electrode which is supplied with a modulated flow of gas which it causes to whirl. Application in high power plasma torches for regularizing and rendering uniform the wear of the electrodes so as to prolong the life thereof.

Abstract: This invention relates to a process and device for destroying solid waste by pyrolysis, in which a column of such waste is upwardly traversed at least partially by a stream of hot gas blown in at the base of said column, wherein said stream of hot gas is generated by at least one plasma jet. The invention results in the destruction of non-burned residues and in the improved flow of the molten residues.

Abstract: The present invention relates to an ionized gas generator with supersonic homogeneous flow. This generator comprises unitary modules comprising:two coaxial electrodes of cylindrical form, the downstream electrode being open and having the flow passing therethrough;means for injecting as vortical gas along planes perpendicular to the axis common to said electrodes, the gas thus injected passing through an electric arc which consequently takes an elongated form;means for striking the arc between the two coaxial electrodes;means for cooling the electrodes, the gas injection devices and the coupling chamber;coils creating around the first upstream electrode a magnetic field ensuring the displacement of the base of the arc around the inner surface of said upstream electrode.The invention is applicable to testing of heat-protection materials.