Abstract: A device for separation of gas by adsorption, of the so-called VSA or MPSA type, comprises, between a utilization line (L) and a source (S) of gaseous mixture to be separated, at least one module (M) comprising in series a reversible rotary machine (R), typically a Roots machine, an adsorber (A) and a shut-off valve (V), the rotary machine (R) being alternately actuated, in one direction during a first phase of pressurization and of production and then, in the other direction, during a second phase of depressurization and desorption. Used particularly in the production of small and medium volumes of oxygen in modular installations.

Abstract: A fluid distributor for heat and material exchange columns, more particularly of the packed type, comprising profiled elements (2) of inverted U shape with substantially vertical walls (4), and a base (1) in which are formed a plurality of parallel slots (9). Each slot is covered by one of the profiled elements, secured to the base by the walls (4) in a permanent and sealed manner. The base (1) is a flat plate. Each profiled element (2) is fixed to the two opposite edges of its slot (9) by welding. Each of the walls (4) terminates in at least one foot (7) turned inwardly of the element (2) and parallel to the surface of the base (1), the feet (7) serving to attach the elements to the base.

Abstract: A composite structure comprising:(i) a solid electrolyte which is an O.sup.2- anion conductor and essentially impermeable to gases;(ii) a cathode; and(iii) an anode, wherein the cathode and anode are porous to gases and wherein the electrolyte is in contact with the cathode and anode,wherein at least one of the cathode and anode is a voluminal electrode comprising (a) at least one BIMEVOX compound and (b) an electronic conductor, forming a distinct solid phase, dispersed in the BIMEVOX compound so as to define, within respective volumes of the voluminal electrode, a plurality of triple contact points between an ambient gaseous atmosphere, the electrolyte, and the electronic conductor.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: An installation for the production of argon comprising a double column (1, 3) and an argon purification column (5). An auxiliary column (9) serves to effect the nitrogen-oxygen separation, and is supplied by a stream from the low pressure column (3). Therefore, nitrogen does not contaminate the stream sent to the argon purification column (5).

Abstract: A process for melting glass in a horseshoe-flame furnace including a rear, a forward and a lateral wall and a longitudinal axis comprising the steps of: introducing a charge into a region of the rear wall of the furnace; running the charge, in succession in a longitudinal direction, through a melting zone to completely melt the charge and form a glass bath, through a homogenization zone and then through a refining zone; evacuating the melted and refined glass into a region of the forward wall of the furnace; sending an air-fuel flame from a first region in the rear wall which is staggered with respect to the longitudinal axis of the furnace, evacuating smoke from a second region of that same rear wall essentially symmetrically to the first region with respect to the axis; periodically alternating the first and second regions; and sending at least one oxidized fuel flame above the refining zone from a point on the lateral wail adjacent to the second region which is situated opposite the refining zone.

Abstract: Process for treating a gas mixture by pressure swing adsorption wherein for each adsorber (1), the duration (T.sub.R) of the countercurrent recompression step is much less than that (T.sub.D) of the cocurrent decompression step. The process is particularly useful in the production of oxygen from atmospheric air.

Abstract: The burner comprises a tap-hole block (1), a burner body (C) substantially comprised of a tubular element (2), at least one injection blowpipe (3) extending through the burner body and into the cavity (P) of the tap-hole block (1), and unlockable quick mounting means (22, 20, 16, 23, 26, 28) for mounting the injection blowpipe (3) to the tubular elements (2) and the tubular element (2) to the tap-hole block (1). Application particularly to the oxicombustion in glass furnaces.

Abstract: A sterilizable installation for supplying at least one dose of a cryogenic liquid to a use station, wherein said installation comprises, along a fluid transfer line;a source of a first cryogenic liquid;a reservoir, suitable for temporary storage of the first cryogenic liquid, comprising a plural number of parts which are assembled using welds executed according to welding techniques that produce total penetration with no lap between two welded parts, such that the reservoir does not include rough spots or other sites of bacterial contamination and providing resistance to temperature fluctuations; andmeans for withdrawing, in continuous or discontinuous fashion, the first liquid from the reservoir to supply the use station.

Abstract: A fluid circulation apparatus comprises a body part (2) in the shape of a dihedron with, on a first face of the dihedron, at least one opening for input/output of this fluid covering over the opening in a leaktight way. The bulb projects with respect to the body part (2) beyond the edge (13) of the dihedron and is produced by combination of metal sheets, of cylindrical, spherical and/or ellipsoidal shape, welded to one another. The apparatus is applicable to the integration of phase separators with heat exchangers of the brazed-plate type or alternatively to the input/output of fluids in such exchangers.

Abstract: Processes and systems to recover at least one perfluorocompound gas from a gas mixture are provided. In one embodiment the inventive process comprises the steps of a) providing a gas mixture comprising at least one perfluorocompound gas and at least one carrier gas, the gas mixture being at a predetermined pressure; b) providing at least one glassy polymer membrane having a feed side and a permeate side; c) contacting the feed side of the at least one membrane with the gas mixture; d) withdrawing from the feed side of the membrane as a non-permeate stream at a pressure which is substantially equal to the predetermined pressure a concentrated gas mixture comprising essentially the at least one perfluorocompound gas; and e) withdrawing from the permeate side of the membrane as a permeate stream a depleted gas mixture comprising essentially the at least one carrier gas.

Abstract: A method of bleaching recycled paper containing pulp wherein said pulp is contacted with ozone in an ozone stage (Z) treatment with a brightness stabilizing step during or at the end of said ozone stage (Z), said stabilizing step consisting of contacting a small amount of hydrogen peroxide with said pulp, the amount of hydrogen peroxide contacted with said pulp being small compared to the amount of hydrogen peroxide usually in an hydrogen peroxide stage, no washing step of the pulp being provided between the ozone contacting step with said pulp and the hydrogen peroxide contacting step. The pulp is first submitted to a test procedure to determine whether the pulp is more reactive to ozone in acidic or alkaline conditions, and if necessary the pH is accordingly adjusted.

Abstract: According to the invention, the content of peracid, in the presence of hydrogen peroxide, in a solution 2 in which the molar ratio between the concentration of hydrogen peroxide and the concentration of peracid is not higher than 100, is adjusted by means of a process according to which it is drawn by means of a pump 3 into the suction circuits of two pumps 5, 6 which operate at the same flow rate and may draw simultaneously a dilution and/or pH control liquid 9, pump 5 feeding the reference vat 7 of a two-beam photometer and pump 6 feeding its measuring vat 8, and the flow rates of the pumps 3, 5, 6 being adjusted so that the concentration of peracid in the measuring flow 10 is lower than about 100 ppm by weight, an excess of iodide 11 is added to the measuring flow 10 which exits from the pump 6 by means of a pump 13, a measuring unit 14 to which are connected the cells of the photometer compares the intensity of the iodine color formed in the measuring vat 8 to the reference in the reference vat 7 and tran

Abstract: A device for creating a deposit of silicon oxide on a traveling solid substrate, wherein the substrate is subjected to an electrical discharge with a dielectric barrier in the presence of a controlled atmosphere containing a silane and an oxidizing gas, the atmosphere being at a pressure higher than 10,000 Pa, and wherein the atmosphere is maintained in the immediate vicinity of an electrode in the region where the electrical discharge is produced and further wherein any entrainment of oxygen other than that forming part of the atmosphere in the region is prevented.

Abstract: The shielding gas mixture for the TIG or GTAW arc welding of stainless steels, in particular of duplex or super duplex steels, comprises, in argon, from 3 to 18%, advantageously approximately 10%, of helium and from 1 to 3%, advantageously approximately 2%, of nitrogen. This gas mixture makes it possible to ensure good corrosion resistance of the metal deposited, acceptable solidity of the welds and excellent arc stability, as well as a suitable viscosity of the molten metal appropriate to manual welding in all positions.

Abstract: A process and a plant in which gaseous oxygen is produced directly at the desired high pressure by pumping liquid oxygen drawn off in the vessel of the low-pressure column (11). The air to be distilled is split into three flows: a flow at the medium pressure of the double distillation column (1), a flow at a high pressure, higher than approximately 60 bars, and a flow at an intermediate pressure which, after partial cooling, is expanded to the medium pressure in a turbine (8). The intermediate pressure is chosen so that the air treated in the turbine is near its dew point at the entry of the turbine wheel. Liquid product is simultaneously drawn off (at 24) from the plant.

Abstract: A plant for generating a nitrogen-based gas is provided. The plant includes a source of impure nitrogen under pressure containing a residual oxygen concentration; a main gas conduit; a catalytic deoxygenation reactor; a secondary gas line connected to a source of a secondary reducing gas at one end thereof and to the main gas conduit at a point situated upstream of the catalytic deoxygenation reactor at another end thereof; and a device for removing water vapor present in a gas. The source of impure nitrogen is connected to the catalytic deoxygenation reactor via the main gas conduit. The main gas conduit between the source of impure nitrogen and the point where the secondary gas line is connected is devoid of any flow control device.

Abstract: Wave soldering or tinning machine comprising:a solder reservoir;a means that forms at least one solder wave having a laminar form and including a flat surface;a means for bringing a piece to be soldered or tinned into contact with the laminar wave; andmeans for injection of a gas in the vicinity of the wave comprising an injector located in a position adjacent to and downstream from the wave and provided with a wall facing the solder wave, wherein the wall has at least a first group of openings positioned so as to produce a first gas jet directed toward the flat surface of the solder wave.

Abstract: A method for wave soldering a circuit having two or more faces comprising the steps of:(i) passing at least one initial gas mixture comprising at least one of an inert gas, a reducing gas and an oxidizing gas into at least one apparatus for forming excited or unstable gas species;(ii) converting the at least one initial gas mixture into at least one primary gas mixture comprising excited or unstable gas species and substantially free of electrically charged species;(iii) treating each of the two or more faces of the circuit with the at least one primary gas mixture at a pressure close to atmospheric pressure; and(iv) contacting the two or more faces of the circuit with at least one wave of a liquid soldering alloy.

Abstract: A motor is supplied with electricity across a transformer (T) which outputs on a busbar (J) which is connected to the motor (M) and to other electrical energy consuming devices, the motor by itself consuming an active power greater than or equal to 20% of the available electric power. During at least a part of the starting period of the motor, the motor is supplied with reduced voltages taken on intermediate taps (P.sub.1, P.sub.2, P.sub.3) in the secondary windings of the transformer (T).