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 water film cooling modular nozzle for high temperature testing of specimens or similar comprising a rather long divergent in relation to the throat diameter, consisting of a metal section including the convergent, the throat and the beginning of the divergent and one or several divergent sections also metallic, the various sections being end to end assembled, and in that the outer wall of each section is independently cooled with a thin water film, the unit consisting of the sections and the separators being enclosed in a fixed outer shell defining, opposite each section, an independent cooling fluid circulation chamber containing the separator, the arrangement being such that a clearance with respect to the longitudinal axis of said unit in relation with said shell is allowed in order to absorb the thermal expansion of the nozzle.

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: A method and device for forming a modifiable closed volume (16) by means of an extensible and retractable tubular element (16) fixed around the orifice of a sleeve (3) closed by a valve (5) on the upstream side of the valve, and detachably fixed around the nose (12) of the torch (4), and balancing the pressure in the volume (16) on the upstream side of the valve with the pressure prevailing on the downstream side of the valve by a device (20, S), opening the valve and reducing the volume (16) by advancing to the mounted position the nose (12) of the torch and locking the torch (4) on a sealing element (7) of the sleeve.

Abstract: The device for mounting and withdrawing a plasma torch in an apparatus at high pressure and temperature comprises in combination: at least one circular sealing element (2) interposed between the inner surface of a sleeve (3) and a nose (12) of the torch (4) and surrounding the nose, devices (6, 13) for balancing the pressures on each side of a valve (5) within the sleeve, and devices (18,23) for cooling the sealing element. The devices for balancing the pressures on each side of the valve comprise a communication pipe (6) by-passing the valve (5) and a tap valve (13) inserted in the pipe.

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 relates to a process and device for injecting at least one stream of a finely divided material into a hot gaseous flow, such as a plasma jet. According to the invention,--there is interposed on the path of said hot gaseous flow a screen pierced with a plurality of orifices spatially distributed about said hot gaseous flow so as to fractionate the latter into a plurality of elementary flows at least approximately in the same general direction; and--said stream of finely divided material, is led to at least one nozzle at least partially surrounded by said orifices, in order to create at least one stream of finely divided material whose direction is at least approximately similar to that of said elementary hot gaseous flows and surrounded by at least certain of them. The invention is particularly applicable to plasma chemistry.