Abstract: 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.

Abstract: A furnace comprises a space overlying a charge into which space opens at least one oxygenated gas injector passing through the periphery of the furnace to deliver within this space a jet of gas that is nonradial relative to a vertical axis of the space. Each injector comprises a) a head (14) disposed within the thickness of the wall (1) of the furnace and having a gas passage having an axis (11) inclined at a predetermined angle (.alpha.) to an axis (15) that is substantially radial relative to the vertical axis of the space overlying the charge and b) a substantially cylindrical body (16) prolonging the head and the gas passage within the furnace along this substantially radial axis (15), itself substantially perpendicular to the wall (1) through which it passes. The injector is useful in an electric furnace for melting scrap for the production of steel.

Abstract: Particular mixed vanadium/other metal catalysts, well suited for the desulfurization of gaseous effluents containing contaminating amounts of objectionable sulfur compounds, typically via the Claus reaction and notably in the presence of oxygen, comprise a support substrate, e.g., titanium dioxide, having an active catalytic phase deposited thereon, such active catalytic phase being constituted of an electroneutral solid solution having the average composition:A.sub.4.+-.y V.sub.2.+-.x O.sub.9in which A is a metal other than vanadium, e.g., magnesium, calcium or zinc, 0.ltoreq.x.ltoreq.0.2 and 0.ltoreq.y.ltoreq.0.5.

Abstract: Avoidance of the corrosion initiation sites consisting of Mn particles deposited on the TiG welded inner tube surface is achieved through suppression of emission of manganese fumes by addition of a protective non corrosive metallic layer. The latter melts during the welding and arises in a non-corrosive internal metallic coating of the welded zone.

Abstract: A process for thermal debinding and sintering of a workpiece made by molding a mixture of a binder and a powder, the process entailing the steps of injection molding a workpiece entailing at least 30% vol. of binder, the binder containing from about 70% to about 90% wt. of at least one wax and from about 10% to 30% wt. of high molecular weight polymer, introducing the molded workpiece in an enclosure at ambient temperature, injecting an atmosphere of at least 95% vol. hydrogen and less than 5% vol. water vapor, heating the enclosure and/or the workpiece until reaching a temperature between about 150.degree. C. to about 200.degree. C., maintaining the temperature during a period of time sufficient to substantially decompose all the waxes in the binder, then heating again the enclosure and/or the workpiece to reach a temperature of about 700.degree. C.

Abstract: A generator produces ultra-high purity nitrogen and ultra-high purity oxygen simultaneously by the liquefaction and rectification of feed air. Feed air is rectified in a first rectification column, and nitrogen gas separated to the top of that column is liquefied, in a nitrogen condenser, by oxygen-enriched liquid air separated to the bottom portion of the first rectification column. The oxygen-enriched liquid is fed to the upper portion of a second rectification column having a reboiler at its bottom, so that through rectification oxygen gas is fed from above a liquid reservoir to the lower portion of a third rectification column. Through rectification of the oxygen gas in the third rectification column, high purity oxygen gas, from which impurities having boiling points higher than that of oxygen have been removed by liquefaction, is fed to the center portion of a fourth rectification column which has a condenser in its top portion and a reboiler in its bottom portion.

Abstract: In this process of the liquid nitrogen/rich liquid HPN swing type, the connection between the head of the column (4) and the liquid nitrogen holding tank (7) is effected, for the two flow directions of the liquid nitrogen, by a single conduit (12) equipped with a pressure reducing device (13). The direction and the flow rate of the liquid nitrogen flow are controlled by the variations of the pressure of the column, and the holding tanks of liquid nitrogen and rich liquid are maintained at constant pressures.

Abstract: The injection of a second gas, in a flow of a first gas which flows in a portion of a main channel, is carried out by an ejection head which is coaxial with respect to the axis of the channel portion and causes a deflection, typically by radial vanes, of the second gas in at least two flows which are directed substantially radially towards the outside, with a tangential component. Application for example to the over-oxygenation of air in processes of oxidation in gas phase.

Abstract: The invention concerns a process for freezing an article, such as a food according to which said article is contacted with the surface of a porous support which is impregnated with a cryogenic liquid. The invention also concerns a device for freezing an article including a conveyor of porous material, which is insulated by means of an enclosure as well as means for impregnating said conveyor with a cryogenic liquid.

Abstract: A cryogenic unit for the separation of gases includes at least one distillation column (1) is preassembled in the factory. The column (1) with added tubing elements (2) constitutes a pre-equipped subassembly which is transported and installed at the worksite. The tubing elements are disposed so as to be inscribed in at least one elongated volume (3; 3.sub.1, 3.sub.2) lateral to the column and of reduced section. The subassembly (1,2) is disposed on at least one transport cradle (4, 4') and transported to the worksite on the cradle and mounted at the worksite in a cold box (10) Preferably, all the tubing elements are disposed in the cradle. The subassembly, with or without the cradle, is mounted adjacent one side wall of the cold box (10) and is spaced by insulation (13) from at least one liquid gas reservoir (11; 12) also in the cold box (10).

Abstract: A first flow of gas (C) accompanying a flow of solid particles (S), is sent at supersonic speed into a first conduit (1) prolonged by a third conduit (8) and intersecting a second conduit (6) supplying a second flow of gas (G) which is deflected into the third conduit (8) to accompany the flow of particles (S) whose trajectory is not substantially modified, the flow of the first gas (C) being deflected, downstream of an oblique shockwave (13) into a fourth conduit (9) forming a separator nose (10) with the third conduit (8). The invention is particularly applicable to the injection, into a reaction chamber (16), of solid particles with a highly oxygenated gas (G) replacing an inert gas (C) for conveying the particles.

Abstract: The invention concerns the preparation of an optical structure. On a polymeric substrate there is first provided a surface activation, and the deposit of a layer of SiO.sub.2, 2000 .ANG. thick after which there is a deposit of a plurality of functional layers and finally a deposit of SiO.sub.2, 3 microns thick followed by a deposit of Si.sub.3 N.sub.4 /SiO.sub.x N.sub.y 3 microns thick, the latter being produced under radio-frequency polarization. The thus obtained optical structure has properties of adhesiveness, resistance to abrasion and to thermal impacts.

Abstract: The tubular rod (7) for sampling, mounted in a duct for the evacuation of fumes for example from a heat treatment or a melting furnace, includes an extractor tube (8) extending in a closed sleeve (9) comprising an inlet (11) and an outlet (12) of cooling fluid, the extractor tube having an end part opening outside the sleeve by means of an opening (10) for sampling fumes and a connecting part (14) extending outside the sleeve for connection to a circuit of analysis including a suction pump. The opening (10) is advantageously directed in counter-current with respect to the direction of circulation (F) of the fumes (11). Application such as for process control in an electrical furnace for the production of steel with injection of oxygenated gas.

Abstract: According to the process of the invention, after heating, nitrogen which exits from a pressure column is compressed under elevated pressure by means of a single nitrogen compressor, and the low pressure column is operated at a pressure of about P.sub.N /.rho..sub.N, where P.sub.N represents the elevated pressure of nitrogen and .rho..sub.N the compression ratio of the nitrogen compressor. Application to the simultaneous production on the one hand of high purity nitrogen at a pressure between 50 and 60 bars, and on the other hand, of oxygen at 65 bars, so as to supply a unit for the production of ammonia.

Abstract: Process and installation for transferring a liquid, via a rising conduit (6, 9, 11, 12) provided with an expansion valve (7, 10, 13), from a first distillation column (2), operating at a first pressure, to equipment (3), particularly a second distillation column, operating at a pressure lower than the first pressure. There is injected into the rising conduit, downstream of the expansion valve, a lift gas available at a pressure greater than the pressure created by a column of liquid between the point of injection of the gas and the point of introduction of the liquid into the equipment (3). The lift gas is available at the pressure of the first distillation column (2) and is injected into the liquid in the rising column above the point of withdrawal of this liquid. There is used as lift gas a gas withdrawn from a point in the first column (2) and so chosen as not to modify substantially the composition of the transferred liquid, or a portion of the air feed to the installation can be used for this purpose.

Abstract: In this nitrogen-cycle installation, the cycle compressor provides a supply of high-pressure nitrogen which serves to heat oxygen supplied in liquid form from the reservoir of a low-pressure column and raised in pressure by a pump to the desired high production pressure. Oxygen gas may be produced at a pressure exceeding about 50 bars.

Abstract: Indirect heat exchanger, of the type comprising a series of parallel plates (7) delimiting between themselves passages (8A, 8B; 28, 42, 60) of generally plate form containing undulant spacers (9; 32, 34, 36, 37, 44, 47, 48, 53 to 56). A first assembly (8A; 28, 60) of these passages constitutes thermal exchange passages having structure (3 to 5; 39 to 41, 51) for inlet and outlet of fluids adapted to exchange heat with each other. Over at least a portion of its length and of its width, the exchanger has added passages (8B; 42), in reduced or no heat exchange relation with the thermal exchange passages (8A; 28, 60) and provided to fulfill at least one function in addition to the exchange of heat, namely a function of storing liquid and/or recirculation of liquid and/or liquid-vapor separation.

Abstract: A process for controlling the carbon content in a metallic piece molded by injection or other process comprising,a) heating the shaped piece under a 100% hydrogen atmosphere up to about 200.degree. C.,b) replacing the 100% H.sub.2 atmosphere by a substantially 100% nitrogen atmosphere and heating the pieces from 200.degree. C. to 450.degree. C.,c) maintaining the temperature in the enclosure at substantially 450.degree. C. while subjecting the pieces to an atmosphere comprising from 15% to 100% vol. hydrogen, the complement being nitrogen, thend) replacing the atmosphere by a substantially 100% nitrogen ande) heating the pieces from 450.degree. C. to substantially 700.degree. C. in order to further eliminate the remaining binder.

Abstract: 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.

Abstract: Process for lubricating a surface for the manufacture of a glass object, in which a layer of lubricant is periodically deposited on the surface.This layer of lubricant is produced with the aid of a source of heat such as an oxyfuel flame having a temperature higher than 2000.degree. K. through which there is injected during a given period of time a gaseous hydrocarbon or a mixture of gaseous hydrocarbons comprising at least 15% of a constituent in respect of which the ratio .[.fo.]. .Iadd.of .Iaddend.the number .[.oc.]. .Iadd.of .Iaddend.carbon atoms to the number of hydrogen atoms C/H is higher than 0.75. The rate of injection of the hydrocarbon through the flame and the temperature of the latter are controlled in such manner as to obtain a porous layer of carbonaceous particles capable of burning in the air when they are deposited on the glass object when the latter is still hot.