Abstract: The plasma torch (10; 11, 12, 14) comprises an electrical power supply (20) with an arc circuit (21) and a coil circuit (22) which are mounted in series and with means (30) for controlling the level of the current flowing in the coil (22) consisting, inter alia, mounted in parallel with this coil (14), of a chopper consisting of a battery of capacitors (31) and of at least one electronic power switch (32) which may be placed distant from the coil. The electronic switch is preferably of the thyristor diode (321, 322) type, with a resonant turn-off circuit (31, 323).A variant of this chopper uses at least one electronic switch of the GTO thyristor type, controllable in triggering and in switching off, or at least one conventional thyristor equipped with an auxiliary extinction circuit.Application to high-power torches, for industrial, for example metallurgical, use.

Abstract: The plasma torch (10; 11, 12, 14) comprises an electrical power supply (20) with an arc circuit (21) and a coil circuit (22) which are mounted in series and with means (30) for controlling the level of the current flowing in the coil (22) consisting, inter alia, mounted in parallel with this coil (14), of a chopper consisting of a battery of capacitors (31) and of at least one electronic power switch (32) which may be placed distant from the coil. The electronic switch is preferably of the thyristor diode (321, 322) type, with a resonant turn-off circuit (31, 323).A variant of this chopper uses at least one electronic switch of the GTO thyristor type, controllable in triggering and in switching off, or at least one conventional thyristor equipped with an auxiliary extinction circuit.Application to high-power torches, for industrial, for example metallurgical, use.

Abstract: The invention relates to a molecular distillation apparatus of the type comprising a metallic conical rotor (12) rotatably driven and fed in its center with a liquid to be distilled, a vacuum bell (10) defining an enclosure housing the cone and means for inductively heating the rotor which are located beneath and in proximity to the latter.According to the invention, the heating means comprise at least two concentric inductors (100a, 100b, 100c) supplying different thermal power densities to homologous regions of the rotor and an inner inductor (100a) supplies a greater thermal power density to the rotor than the power density supplied to the rotor by an outer inductor (100c).The invention also relates to a process for manufacturing an assembly of a rotor and inductors for such an apparatus.

Abstract: The apparatus comprises an endless conveyor band (2) of insulating material on which are mounted at even distances apart receptacles (7) composed of a metal adapted to receive separate portions of a dish to be cooked and inductors (10a, 10b) disposed below the upper reach (6) of the conveyor. The inductors have a diameter roughly equal to one-half of the diameter of the receptacles and are disposed in at least two rows in the direction of movement of the conveyor (2) symmetrically relative to the axis of movement of the receptacles. The inner edges of the inductors (10a, 10b) are located beyond a vertical plane containing the axis of movement of the receptacles (7) so as to insure a homogeneous heating of the receptacles.

Abstract: A regulator system for a switching mode inverter generator feeding an inductively coupled load and seeing the load as a series resonant circuit having a resonant frequency which varies with its magnetic state comprises two switches which connect the load to the output of the inverter. Each switch comprises a switching element and switching terminals. A diode shunts the switching terminals of each switching element of each switch. A control loop slaves the output frequency of the inverter to the resonant frequency of the load. A second control loop is responsive to the inverter power output or the inverter supply voltage. The system is suitable for inductive heating furnaces as used in industry.

Abstract: An electromagnetic induction apparatus for heating metal elements has at least one flat loop magnetic circuit open at its two facing ends, with an inductor wound onto the magnetic circuit. The inductor has two windings wound onto the magnetic circuit, respectively in the vicinity of the two ends of the loop, which windings are supplied by in-phase alternating currents. Each end of the flat loop is chamfered, the ends forming an air gap therebetween, in which the element to be heated is placed.