Abstract: Process and apparatus for the purification of hydrogen by cryogenic treatment of a gas containing also nitrogen oxides and unsaturated hydrocarbons as two types of constituents which react together in an undesirable fashion when cooling achieves an intermediate temperature higher than the low temperature of the treatment. The process comprises cooling the gas to a first temperature higher than that intermediate temperature; eliminating from the gas one of the two types of constituents at this first temperature; and continuing the cooling of the gas to the low temperature. The elimination of one type of component is effected by washing the gas with a liquid adapted to dissolve it. This liquid contains at least one saturated hydrocarbon and is obtained by a partial condensation of an auxiliary gas which contains at least one of hydrogen and a heavy constituent whose value can be increased.

Abstract: A column for production of nitrogen by the distillation of air, adapted to produce high purity nitrogen at its head, is associated with an external source of medium purity liquid nitrogen that is fitted with a device for the liquid phase adsorption of carbon monoxide, and with a reservoir for the storage of high purity liquid nitrogen. The column produces medium purity gaseous nitrogen and high purity gaseous nitrogen by direct withdrawals, optionally supplemented by vaporization of liquid nitrogen.

Abstract: In this process for the production of gaseous oxygen under pressure by air distillation in a double column, pumping liquid oxygen withdrawn at the bottom of the low pressure column, and vaporization of compressed liquid oxygen by heat exchange with air at high pressure, all the air to be distilled is compressed at the high air pressure, followed by expanding, at the pressure of the mean pressure column, the excess fraction of this air in a turbine which is decelerated by means of an air booster, and at least one liquid product is withdrawn from the apparatus.

Abstract: A process for producing gaseous nitrogen from a mixture to be treated in a distillation column, said mixture comprising nitrogen and oxygen, said process comprising the steps of:a) compressing the mixture to be treated to a pressure at least equal to the column pressure;b) cooling the compressed gas mixture and subjecting at least a first portion of said cooled mixture to expansion through a turbine to produce the required refrigeration and thereafter fractionated distillation in the column to obtain at the bottom of the column, an oxygen-enriched fraction and, at the top of the column, a nitrogen-enriched fraction,c) drawing off at least a portion of the nitrogen-enriched fraction as nitrogen product;d) compressing the remaining portion of the nitrogen-enriched fraction;e) recycling at least a portion of the compressed remaining portion of the nitrogen-enriched fraction to the bottom reboiler of the column where it condenses to provide reboil for the column;f) introducing at least a portion of the condensed

Abstract: Process for the recovery of galvanized steel sheet, by remelting with substantial elimination of zinc coating, in which the remelting operation is effected in a rotating furnace (1) under the heating action of at least one flame of fuel and an oxidizing agent which is industrial oxygen. The flame is oxidizing. The furnace is provided with at least one burner (2) for the fuel and industrial oxygen, and a dust catching device (8) in the fume conduit (7) adapted to retain at least a substantial portion of the particles of zinc oxide thus produced. The burner (2) is disposed centrally in an axial end wall (3) of the furnace opposite the fume conduit (7) and the furnace (1) turns in operation about a horizontal axis.

Abstract: Compressed air, feeding a unit for the separation of gases present in air, releases calories to a refrigerating unit which operates by absorption while cooling a flow of liquid in heat exchange relationship with a gas of the apparatus to cool the latter so as to ensure a reduction of the global energy consumption of the apparatus.

Abstract: Heat exchanger with streaming liquid to vaporize a liquid by heat exchange with a second fluid, of the type comprising a parallelepipedal body formed form an assembly of parallel vertical plates (4) defining between them a multitude of flat passages (18, 19) distributed in an assembly of vaporization passages (18), and in an assembly of heating passages (19). Each passage contains an undulant-spacer (20) with vertical generatrices. Structure for distribution of the liquid is provided at the upper end of the exchanger (2) to distribute the liquid over all the length of the vaporization passages (18). Structure (9) is provided to direct the second fluid into the heating passages (19). The distribution structure is disposed in compartments (23) closed at their upper end and situated each above a heating passage (19), from which the compartment is separated by a horizontal strip (22).

Abstract: The apparatus includes two permeators mounted in series, namely a simple permeator with an inlet and two outlets, and a reflux permeator. The production gas results from the combination of the two permeated products. Application to the production of impure hydrogen.

Abstract: The network comprises cells each constituted by a first channel (4, 4') of a material having selectively a superconductive state and a resistive state, refrigeration apparatus to maintain the first channel at a temperature below that which ensures superconductivity of the material below a critical current intensity in the channel, an electrical supply for the channel, and a second channel (5) branched in parallel to the first and having an electrical resistance (R). According to the invention, the two cells are coupled by at least one interconnection channel (8, 9, 10, 11; 8', 9', 10', 11') with unidirectional electrical conduction, extending from the input of one cell to the input of the other cell to input current into this latter or to derive it, a voltage control regulating the intensity of the current flowing from one cell toward the other in the interconnection channel.

Abstract: Transfer line for cryogenic fluid comprising a transfer conduit (1) for cryogenic fluid and a conduit (3) for cooling fluid surrounded by a metallic shield (4) coupled thermally to the cooling conduit (3). The metal shield (4) is a thin strip wound in unsecured manner about the conduits (1, 3) and locally connected to the cooling conduit (3) by resilient clips (5) or by a layer (6) of connecting material. The metallic strip has a thickness no greater than 0.1 mm and can be of aluminum.

Abstract: The line of gas to be analyzed, the "zero" gas line and calibration gas line are each provided with a restriction operating in sonic rate supplying a nominal constant flow and downstream, have a discharge duct provided with a flow regulator. The nominal flows in the first and second lines are higher than the given flow supplied to the analyzer so that during each of the calibration and analysis steps, the whole of the circuit portion of the device is permanently flushed with the nominal gas of the line and/or by a portion of the recirculated flow of gas originating from another line.

Abstract: A membrane nitrogen gas generator, containing a feed stream compressor, one or more filtering membranes, each having a permeate side and a non-permeate side, in fluid connection with and downstream of the feed stream compressor, and one or more product storage containers capable of storing a product having a higher purity than is required by customer demand, and which generator is capable of generating an increased flow rate during periods of high demand.

Abstract: In at least one of the ducts for feeding a fuel and an oxidant to a burner, a device for flow pulsation is provided to cause in the duct a pulsation of the flow of fluid which is fed at a frequency lower than 3 Hz, typically lower than 1 Hz. Application for example to oxycombustible burners of industrial furnaces having high yield and low emission of nitrogen oxides.

Abstract: Process for freezing a product in which said product is contacted with a film made of a liquefied gas of which the boiling point is below -30.degree. C., disposed at the surface of a vibrating support, and the frozen product is at least in part separated from said film of liquefied gas.Device for freezing a product including a vibration generator (7) connected to a support (2) at the surface of which there is disposed a film of liquefied gas (3) of which the boiling point is below -30.degree. C.

Abstract: The process of welding at least two elements of thermoplastic materials includes the step of heating, for projection on the welding area, a flow of projection gas comprising at least 20% helium, the balance consisting of a neutral gas or a mixture of neutral gases. For welding applications with a welding strand, the projection gas is heated at a temperature between 200.degree. and 350.degree. C. For applications involving the production of filamentary windings, the projection gas is heated at a temperature higher than 1000.degree. C.

Abstract: A process for coating powders with ultrafine particles of silicon, silicon oxide, silicon nitride or alloys thereof, entailing:a) introducing a reactant gas into a bed of core powders, thereby uniformly suspending the core powders in the reactant gas,b) entraining the uniformly suspended core powders into a chemical vapor deposition (CVD) reactor,c) selectively forming ultrafine particles of silicon, silicon oxide, silicon nitride or alloys thereof in the gas phase by homogeneous deposition of the reactant gas, while minimizing core powder growth by CVD at surfaces of suspended core powders, andd) coating the core powders with the ultrafine particles of silicon, silicon oxide, silicon nitride or alloys thereof, by introducing hot inert gas into the uniformly suspended core powders in the reactant gas.

Abstract: The heating and/or the cooling of the three columns is ensured by a closed nitrogen cycle. Carbon monoxide is withdrawn in liquid form from the third column, then is brought through a pump at the pressure of utilization and is warmed under this pressure.

Abstract: A process for separating dioxygen from a gaseous mixture containing dioxygen, which entails:a) absorbing dioxygen by one or more transition metal complexes at a low oxidation state of the formula (A):(L.sub.n (M.sup.+p).sub.m (X.sup.-z).sub.x.sup.mp-xz (A)the absorption causing formation of a peroxo dihapto deoxygenated product complex of the formula (B):(L.sub.n '(M.sup.p+2 O.sub.2).sub.m' (X.sup.-z).sub.x).sup.m'p-x'z(B)b) desorbing oxygen from the complex by electrochemically oxidizing the peroxo dihapto product complex obtained by reaction of the complex of the formula (A) wiht O.sub.2 : andc) recovering the absorbed oxygen.

Abstract: The present invention concerns a polyphase particulate composite material containing a microporous phase which is essentially carbon whose microporous volume is between 0.1 cm.sup.3 /g and 1 cm.sup.3 /g, which is associated with an amorphous mineral dispersed phase essentially consisting of an oxide of silicon, aluminum, titanium or magnesium disposed on the carbon phase, at a thickness of less than 10 nm. The invention is also concerned with a process for the preparation of these composite materials, and the use thereof as a molecular sieve.

Abstract: The apparatus is of the type having a double column and a mixing column. The latter is fed at the bottom portion with auxiliary air that is compressed at a pressure different from that of the mean pressure column, and at the top by means of a liquid withdrawn from the bottom of the low pressure column and pumped at the same pressure as the auxiliary air. Impure oxygen is withdrawn at the top of the mixing column as production gas, and substantially pure oxygen is produced at the bottom of the low pressure column.