L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des

L'air Liquide, Soci&#xe9;t&#xe9; Anonyme Pour L'etude Et L'exploitation Des Proc&#xe9;d&#xe9;s Georges Claude

L'air Liquide, Societe Anonyme a Directoire Et Conseil De Surveillance Pour L'etude Et L'exploitation Des Procedes Georges Claude

Daniel Guerin

Christian Larquet

Bruno Marie

Antoine Willemot

Michel Moisan

Jean-Christophe Rostaing

Pierre Karinthi

Alain Villermet

Michel Gastiger

Frederic Bernard

Pierre Didier

Valerie Borg

Thierry Sindzingre

Stephane Rabia

Zenon Zakrzewski

Roxane Etemadi

Dariusz Czylkowski

Mariusz Jasinski

The invention relates to a microwave plasma exciter device which includes a waveguide () for concentrating the microwaves; and a plasma generator () for forming a plasma, which are disposed in a microwave concentration zone.

Microwave plasma exciters

A section of pipe, for a device for treating a gas by exciting the latter by way of incident microwave radiation suitable for producing a surface-wave plasma in the gas, including a discharge tube made of dielectric material intended to pass through the device in a region for concentrating the incident radiation. The tube comprises, over at least part of its length, a double wall.

Section of pipe for a gas treatment device and device incorporating such a section of pipe

The invention relates to a process for the dry surface treatment of at least one metal surface portion, according to which the portion is treated at a pressure close to atmospheric pressure by a gaseous treatment atmosphere comprising excited or unstable species and substantially devoid of electrically charged species, obtained from a primary gaseous mixture and if necessary an adjacent gaseous mixture, the primary gaseous mixture being obtained at the gas outlet of at least one device for the production of excited or unstable gaseous species, in which an initial gaseous mixture comprising an inert gas and/or a reducing gas and/or an oxidizing gas has been converted, the adjacent mixture not having passed through the device.

Process and apparatus for the dry treatment of metal surfaces

The gas mixture leaving the laser apparatus (1) is recycled to a permeator (45) which separates it into two flows. The discharge from the permeator is expanded in an expansion turbine (27) coupled to a compressor (35) for exerting suction on the recycled mixture, which makes it possible to obtain the desired reduced pressure in the laser apparatus. Applications to power laser apparatuses with nitrogen/carbon dioxide mixture, intended for cutting materials.

Device for feeding a gas-mixture laser apparatus, and laser apparatus

The invention relates to a process for producing disilane from monosilane, according to which gaseous monosilane is passed into a reaction zone where it is subject to an electric discharge generated by a high-frequency current.

Process for preparing disilane from monosilane by electric discharge and

A process for producing disilane from monosilane comprising introducing monosilane into a reaction zone in which the monosilane is subjected to an electric discharge generated by a high frequency current. The monosilane is mixed with at least one inert gas selected from the group consisting of helium and argon. The pressure of the gaseous mixture in the reaction zone is between 0.1 and 3 bar, and the gaseous mixture is contacted in the reaction zone under electric discharge with a wall cooled to a temperature which is sufficiently low for the saturation vapor pressure of the disilane to be negligible, but not low enough for the monosilane to condense at the working partial pressure. Apparatus for conducting this process is provided.

Apparatus for the formation of excited or unstable gaseous molecules, comprising a tubular gas passage (5) having an axis, formed between a first electrode (1) and a dielectric tube (3) coaxial to the first electrode and supporting a second electrode (4), the electrodes being connected to a high voltage high frequency source (13). The first electrode (1) surrounds the dielectric tube (3) and comprises an elongated gas inlet (7) and outlet (8) parallel to the axis and diametrically opposed to each other on opposite sides of the dielectric tube (3). The second electrode (4) is a layer of metal applied to the internal wall of the dielectric tube (3). The second electrode (4)is formed by metallization of the internal wall of the dielectric tube (3). The gas inlet (7) and outlet (8) have a height not exceeding the radial thickness (e) of the gas passage (5). The external wall of the dielectric tube is covered with a thin layer (21) of enamel. A refrigerant such as Freon circulates within the dielectric tube (3) and the second electrode (4). Used for the production of ozone, to supply a mixed CO.sub.2 laser, or for the production of atmospheres for nitriding metal, or for the production of reducing atmospheres.

Apparatus for the formation of excited or unstable gaseous molecules and

Mixing power laser apparatus, comprising a generator of a flow of excited nitrogen (1), and structure (6; 19) to introduce a flow of CO.sub.2 into the flow of excited nitrogen. The generator (1) is of the cold corona electric discharge type operating at a pressure greater than 0.3.times.10.sup.5 Pa, and is coupled to a waveguide (2) with mirrors (3, 4) opposed along a principal direction of the waveguide. For use particularly in cutting material.

Gaseous mixture power laser apparatus

A power laser has a cavity (2) delimited at its opposite ends by a first partially transmitting window (3) and a second reflecting window ( 4). The first window (3) is constituted by at least one diamond wafer (5) with uncoated flat parallel surfaces, having a controlled thickness whose variations do not exceed 0.2 micron. The diamond wafer (5; 6) is mounted in an annular support (9; 10) of material which is a good heat conductor and is provided with a cooler (11; 12). The window (3) can comprise two parallel wafers (5.sub.A, 5.sub.B) of diamond separated by a calibrated distance (14) which is an uneven multiple of .lambda./4n, .lambda. being the laser wavelength and n the index of refraction of the medium between the wafers. Or the second window (4) can also be constituted by a diamond wafer (6) with a reflective metallic coating (60). A sweeping gas can be blown over the internal surface of at least one of the windows.

Growing community of inventors

Chelles, France

Daniel Guerin