Abstract: In this process for vaporizing a liquid in first ducts, or vaporization ducts, which are opened at top and bottom, of a plate type heat exchanger, by heat exchange with a main calorigenic fluid which circulates in second ducts of the exchanger, additional gas is generated permanently in the lower end part of the first ducts, for example by means of a compartment in which there is a circulation of an auxiliary fluid which is warmer than the main calorigenic fluid. Application to the main vaporizer-condensers of apparatuses for the distillation of air with double column.

Abstract: The liquefaction process comprises the stages of pre-cooling (3) the gas, of cooling it by heat exchange (6, 7, 8) and by fractional expansion (10, 11), under supercritical conditions, then of expanding it in a turbine (9) which delivers a volume of subcooled liquid (2). The process is especially applicable to the refrigeration of superconductive elements.

Abstract: A gas under pressue is sent to a first compartment of a separation module having permeation membrane, the first modified gas mixture which exits from the first compartment being introduced into the enclosure to constitute therein a controlled atmosphere which is removed and circulated in counter-current in the second compartment of the module towards the discharge orifice of the latter so as to substantially recombine the two gaseous modified mixtues before discharging same thereby increasing the performances of the separation module.

Abstract: To compensate for load losses in a downstream part of a line for supplying gas under controlled pressure through a valve which is controlled by a pick-up upstream of the line, the pressure read by the pick-up is supplied by a pressure intake which is formed in a tube extending in the line and which is angularly orientable with respect to the flow of gas delivered. Application for example to systems of supplying breathing gas to the passengers of an airship.

Abstract: The invention relates to a process for preparing interconnection substrates of hybrid circuits, comprising effecting on a support the deposition of a thick layer of ink or paste based on a non-noble metal, such as copper or other material having a "copper compatible" formulation, by carrying out in succession a preliminary drying for eliminating solvents at a temperature on the order of 100.degree. C. to 150.degree. C., a firing comprising:a) a temperature rise incorporating a stage for eliminating polymer resins,b) a sintering step at a temperature on the order of 600.degree. C. to 1000.degree. C., andc) a timed cooling,the firing being carried out under a substantially inert gas atmosphere (nitrogen and/or argon and/or helium), the atmosphere of the stage for eliminating the polymer resins having a content of water vapor lower than 15,000 ppm, preferably between 1,000 and 10,000 ppm, while the atmosphere for sintering at high temperature has a content of water vapor in any case lower than 1,000 ppm.

Abstract: A metallic oxide catalyst, containing cupric oxide and an amount of one or more of AgO, HgO or CdO effective for enhancing the ability of the catalyst for removing gaseous hydrides from a gas stream.

Abstract: An adsorber having an upright longitudinal extent includes two perforated parallel panels extending within the vessel formed therein and spaced apart defining an adsorbent mass chamber. The adsorbent mass is in two longitudinal parts having a first part of fine particles and a second part of larger particles. The gas to be treated is circulated horizontally between the two perforated panels. This device allows the treatment cycle to be less than 60 seconds with the same or better performance. This adsorber and process are preferably used for the separation of oxygen from air.

Abstract: Process for melting a furnace charge, with post-combustion of the smokes by njecting an oxygenated gas in the furnace atmosphere as a series of jets flowing according to a tangential component in the space between electrodes and cylindrical furnace partition of the furnace, in a direction of injection so as to produce a rotary gas current about the vertical axis of the furnace and preferably in at least two series as two stepped levels to produce gas currents which rotate in opposite directions. Applications to electrical furnaces for the production of steel or ferro-alloys.

Abstract: A device for providing a non-oxidizing atmosphere above a soldering bath in a vat of a machine for wave soldering, includes a hooding assembly closing the vat, an inner space and a conveyor for electronic circuits extending through the inner space. The inner space is separated from the surrounding atmosphere through seals disposed along the path of the circuits. There is structure for providing and maintaining a non-oxidizing atmosphere in the inner space, for example an inert gas or a mixture of inert and reducing gas.

Abstract: A protective structure for a shut-off valve of a transportable toxic gas container having a metallic hood unlockably mounted on the container around the shut-off valve, comprises a cover made of a shock absorbent material, which is unlockably mounted, typically by a hoop, on the hood and entirely closing the latter. The cover includes an inner recess substantially following the outlines of the hood and an end area resting on the area of the container at the base of the hood.

Abstract: Temperature maintenance and metallurgical treatment furnace for a metal in liquid state, comprising a closed container for liquid metal provided with a burner of the oxygen-combustible type, a porous plug for the bottom of the container for injecting a neutral stirring gas, and openings for the introduction and/or the removal of metallurgical treatment products. The container is in the form of an insulated enclosure which is rockable about a support axis, with two ducts with vertical component, one which is in the form of a chimney opening in the enclosure close to the vault of the enclosure and serving for the introduction of liquid metal and metallurgical treatment products, the other which is in the form of a chute opening at the level of the bottom of the enclosure and in which the upper opening is in position of liquid metal removal in a rocked position of the enclosure. The burner is mounted in the vault of the enclosure.

Abstract: Alkaline aqueous liquid bleaching detergents that remain stable during storage contain monohydrated sodium perborate, a Mg 3.5 SiO.sub.2 magnesium silicate, sodium acid pyrophosphate and a viscosity regulator composed of dialkylether polyethyleneglycol copolymers.The detergents can be used for washing and bleaching at temperatures between 40.degree. and 90.degree. C.

Abstract: Metallization of ceramics of the type comprising depositing a metallic paste based on molybdenum and/or tungsten and manganese on a ceramic substrate and effecting the sintering of the paste in an atmosphere having a predetermiend oxido-reduction potential, with a rise in and a maintenance of a temperature between 1300.degree. C. and 1600.degree. C., then cooling to ambient temperature, with production of an atmosphere by the addition to a pure neutral gas of a quantity of additional oxygen and a quantity of hydrogen at least sufficient to subsequently obtain by catalytic reaction the desired content of water vapour and contingently the excess content of hydrogen.

Abstract: The incoming compressed air is partly expanded in a high pressure turbine, after which a portion of the expanded air is again expanded in a low pressure turbine. The inlet temperature of the latter is clearly higher than that of the high pressure turbine. Application to the production of liquid nitrogen and liquid oxygen.

Abstract: As soon as the apparatus is started, a flow of liquid nitrogen which is at least equal to the nominal flow of gaseous nitrogen is introduced in the head portion of the column, then the flow of liquid nitrogen is adjusted to a small fraction of this nominal flow. Application to the production of a flow of gaseous nitrogen which is variable and moderate.

Abstract: Process for melting and refining a charge which is continuously introduced in raw condition at the inlet of a furnace and extracted in liquid condition at the bottom thereof, with heat transfer towards at least a substantial portion thereof by wall mounted flame burners directed towards the charge in which at least part of the flames result from the combustion of an industrial mixture of fuel and oxygen. For one or more of the flames in the refining zone, there is provided a pulsating combustion with cyclic variations of the oxygen and fuel feeds, including periods of maximum activity with flames of high heat capacity which alternate with periods of rest with substantially reduced and even completely nullified heat capacity. Application for example to the preparation of glass.

Abstract: Process for heat treating articles by hardening them in a recirculating gas medium which is in contact with the treated articles, the hardening gas being cooled by means of a heat exchanger, of the type in which helium is used as hardening gas, and is stored under holding pressure in a buffer container, wherein at the end of a hardening operation, a helium load is extracted from the treatment enclosure, in final phase by means of pump until a primary vacuum is obtained, the extracted helium is brought to purifying pressure by means of a compressor associated to a mechanical filter, and the helium under purifying pressure is sent to a purifier in which impurities are removed, after which it is transferred, if desired, after recompression in the buffer container.

Abstract: The present invention provides a process for producing standard gas mixtures which entails purifying a raw gas using a gas purifier (3) such as a known two stage gas purifier system, thereby generating a high-purity diluent gas;mixing the high-purity diluent gas and at least one high-concentration standard gas, by generating a medium-concentration gas mixture;dividing the medium-concentration gas mixture into a first flow and a second flow;selectively mixing the first flow with a sample gas or a high-purity diluent gas or a mixture thereof, thereby obtaining a standard low-concentration gas mixture; andcontrolling the pressure of the sample gas, the second flow of the medium-concentration gas mixture and the standard low concentration gas mixture.

Abstract: A jacket encloses a packet of corrugated plates (3) each disposed in a generally vertical plane, the corrugations being oblique and descending in opposite directions from one plate to the following plate. Each corrugation valley (5) has a lower end opening out laterally which includes a projecting obstacle (7) in the vicinity of this lower end. In this way, liquid that would otherwise accumulate on the vertical walls of the jacket, where it would participate relatively little in heat and material exchange, is instead diverted toward the interior.

Abstract: The apparatus for determining the quantity of impurity in a gas by chromatography in gas phase comprises a device for cryogenically trapping impurities, which is provided with a column filled with granular particles of a product capable of adsorbing the impurities, refrigerating means capable of keeping the column at low temperature during passage of the gas loaded with impurities and reheating means for an ulterior desorption;a first chromatographic adsorber in gas phase intended for a preliminary analysis and provided with a filling column for each impurity;a device for the cryogenic recentering of the purities, which is provided with a capillary column, refrigerating means capable of keeping the column at low temperature during the passage of a carrier gas which has gone through the first chromatographic adsorber, and desorption reheating means;and a second chromatographic adsorber in gas phase provided with a capillary column, a detection device being mounted at the outlet.