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: An air separation process of the "pumped" type, in which liquid oxygen is removed from a double distillation column and is pumped to a higher production pressure and then vaporized under that pressure. The incoming air is divided into several streams. A first stream is compressed to the medium pressure, cooled and sent to the double distillation column (7). A second stream is compressed above about 25 bars, but below its condensation pressure during vaporization of the liquid oxygen under pressure, then cooled to an intermediate temperature, at which a portion of the air continues its cooling and is liquified (in 20A), then expanded (in 21A) and sent to the double column, while the rest is work expanded (in 4). Use in large size installations for the production of oxygen.

Abstract: A process and installation for the separation of air in a cryogenic distillation apparatus (24) comprising a distillation column (30, 42) and in which the supplied air is separated to produce a fraction rich in oxygen and a fraction rich in nitrogen as products. The purities of these products are maintained substantially constant during variations of demand of either product or of the flow rate or of the pressure of the supplied air by introducing an excess of liquid rich in nitrogen into the distillation apparatus when the demand for the product or the flow rate of the supplied air increases, and by withdrawing an excess of liquid rich in nitrogen from the distillation apparatus, and storing this liquid, when the demand for the product or the flow rate of the supplied air decreases.

Abstract: A process for distributing ultra high purity gases with minimized contamination and particulates including; (a) purging said distribution network or any part thereof with dry inert high purity gas comprising less than 1 ppm of any impurity; (b) evacuating said distribution network or any part thereof at a pressure which is lower than 5.times.10.sup.4 Pascal; (b') optionally wet cleaning a gas distribution network or any part thereof with a wet cleaning agent, thereafter (c) liquid drying the gas distribution network or any part thereof with an H.sub.2 O desorbing liquid drying agent selected from the group including acetone dimethylacetal DMP, 2-2 dichloropropane DCP or 2-2 dibromopropane DBP, mixtures thereof and any equivalent thereof, and (d) distributing an ultra high purity gas through the distribution network or any part thereof.

Abstract: In a process for the preparation of high-purity liquid nitrogen substantially free from at least one of the impurities hydrogen, carbon monoxide and oxygen, liquid nitrogen to be purified is placed in contact with an adsorbent and high-purity liquid nitrogen is recovered. A device for making use of this process includes a source of liquid nitrogen to be purified connected by a conduit to the entry of a reactor containing an adsorbent, the reactor exit being provided with a connecting conduit.

Abstract: Apparatus for measuring the relief profile of a score line mode in a subste such as a paper board. A hand-held measuring head containing a light source illuminates the score line and the back-scattered light reflected therefrom is recorded by a CCD imager. The digital output of the imager is sent to a processor to determine one or more physical characteristics of the score line.

Abstract: A novel process for supplying a gas to an analyzer for measuring traces of impurities in the gas is provided. The process includes the steps of supplying the analyzer with: (i) a gas to be analyzed; (ii) a pure gas; and (iii) a standardizing gas obtained by dilution of one or more impurities in the pure gas as follows: (A) dividing a flow of pure gas into a set of at least first and second bypass lines, arranged in parallel, each of the bypass lines having an entry including a calibrated restriction, the flow of pure gas into the set of bypass lines being regulated by a flow regulator placed upstream of the set, (B) charging the pure gas of the first bypass line with a predetermined quantity of at least one impurity to obtain, after dilution with the pure gas of the second bypass line, a flow of the standardizing gas, which is directed from an exit of the set of bypass lines towards the analyzer along a feed line.

Abstract: Process and installation for the production of gaseous oxygen under pressure by cryogenic distillation of air in a double column (5) comprising a medium pressure column (6) and a low pressure column (7). Rich liquid from the medium pressure column is divided into first and second liquid fractions which are sent to different levels in the low pressure column (7). These different levels are both below the level of withdrawal of impure nitrogen from the low pressure column (7). A fluid enriched in argon is withdrawn from the low pressure column (7) and distilled in an argon column (16). Liquid enriched in oxygen is withdrawn from a lower portion of the low pressure column (7). The two fractions of rich liquid are cooled to different temperatures before being sent to the low pressure column (7). A portion of the supply air is blown into an intermediate level of the low pressure column (7) and the levels of injection of the rich liquid are not below this intermediate level.

Abstract: In a combustion process permitting reducing the production NO.sub.x, there is ejected via a burner (1) at least one flow of combustible gas, at least one flow of an oxygenated gas supporting combustion and at least one flow (10) of one of these gases in liquid phase. In an oxyburner, one portion (between 13 and 35%) of the oxygen is injected in liquid phase. In an aeroburner for natural gas, one portion (10 to 30%) of this latter is ejected in a coherent liquid jet. Use particularly in glass furnaces and heaters.

Abstract: The present invention relates to an electrochemical cell comprising a solid electrolyte conductive for O.sup.2- anions in contact with an anode and a cathode of identical or different composition, the electrolyte solid being comprised of a composition derived from Bi.sub.4 V.sub.2 O.sub.11 of which at least one of the cationic constituent elements is substituted by at least one substituting element chosen such that the gamma phase structural type of Bi.sub.4 V.sub.2 O.sub.11 is maintained, as well as the equilibrium of charges, at least one of the anode or the cathode including two parts, a first part being of a mixed electronic and ionic conductive material in contact with the solid electrolyte, the second part being an electronic conductive material superposed on the first part. The invention equally relates to the use of the electrochemical cell with a view towards the separation or the extraction of oxygen.

Abstract: A process and apparatus for the liquefaction of hydrogen, of the type using a refrigeration cycle whose cycle fluid comprises mostly hydrogen, and a closed liquid nitrogen refrigeration cycle. The cycle fluid is hydrogen and a mixture of C.sub.2 + hydrocarbons. The hydrocarbons are liquefied and expanded to form fluids which vaporize in a substantially continuous manner between a temperature of the order of -120.degree. C. and a temperature adjacent ambient temperature. More particularly, the mixture of hydrocarbons is saturated C.sub.2, C.sub.3, and C.sub.5 hydrocarbons, and if desired C.sub.4, and separated liquefied fractions of these hydrocarbons are expanded at respective temperatures before expansion of the order of 0.degree. C. to -10.degree. C., -40.degree. C. to -50.degree. C. and -110.degree. C. to -120.degree. C., to form refrigerant liquids adapted to be vaporized.

Abstract: A regenerator is provided which has an annular heat-storage medium composed of bulk material (16) and disposed between two coaxial cylindrical gratings (2 and 3, respectively), a hot collecting chamber (4) enclosed by the inner, hot grating (3) and a cold collecting chamber (6) enclosed between the outer, cold grating (2), on the one hand, and the housing wall (1) of the regenerator, on the other, in which regenerator the hot collecting chamber (4) is closed off by a lid (9) resting on the upper rim of the hot grating (3) and there is provided, at a distance above the lid (9), a shield (11) which is attached to the housing wall (1) of the regenerator and is not physically linked to the lid (9).

Abstract: According to the process the substrate (2) is subjected to an electrical discharge with a dielectric barrier, for example a discharge in the presence of an atmosphere containing a silane, an oxidizing gas, NO, N.sub.2 O, CO.sub.2 or O.sub.2, in particular, and a neutral carrier gas such as nitrogen or argon. A controlled atmosphere containing the silane and the oxidizing gas is maintained in the immediate vicinity of the electrode, around the electrode (6) employed for the electrical discharge, while avoiding the process being perturbed by atmospheric air entrained, for example, by the substrate (2) as it travels (3).

Abstract: The present invention relates to an electrochemical cell comprising a solid electrolyte which conducts O.sup.2- anions in contact with an anode and a cathode of identical or different composition, the solid electrolyte being comprised of a composition derived from Bi.sub.4 V.sub.2 O.sub.11 of which at least one of the constituent cationic elements is substituted by at least one substituting element such that the gamma phase structural type of Bi.sub.4 V.sub.2 O.sub.11 is maintained as well as the equilibrium of charges, at least one of the anode or of the cathode is a material containing at least one element of substitution of said composition derived from Bi.sub.4 V.sub.2 O.sub.11, that element being in a metallic or cationic state. The invention equally relates to the use of the electrochemical cell with a view towards the separation or extraction of oxygen.

Abstract: Process and installation for supplying at least one pure active gas to at least one utilization station (P.sub.i) in a first building (A) at a utilization site. It comprises the steps of providing, at the utilization site, a second safety building (B) at a distance from the first building (A), providing at least one source (2; 7; 10) of said gas in the second building (B), and transferring, by at least one safety conduit (C) of high cleanliness, the gas, at a low pressure, to the utilization station (P.sub.i). There is also taught the step of purifying (4; 11) the gas in the second building (B) before transfer to the conduit (C). The pure gas is prepared in situ (2, 4; 10, 11) in the second building (B). There can alternatively be provided, adjacent to the second building (B), at least one source of vector gas (1), with mixing in controlled fashion (6; 9), in the second building (B), the pure active gas with the vector gas before transfer of the mixture to the conduit (C).

Abstract: A gas injection apparatus and process to form a controlled atmosphere in a confined space, comprising at least one assembly of ducts installed in series and/or in parallel, of which at least a part (2, 12, 13) of a duct comprises gas injection apertures. The assembly is supplied by at least one gas supply main (9, 14, 15), each main being connected to the assembly at the level of a primary connection node (8, 16, 17), the dimensions of the assembly observing the following relationship:.SIGMA..omega..sub.i /.SIGMA..phi..sub.i .gtoreq.1, preferably .gtoreq.1.5;wherein .SIGMA..omega..sub.i represents the sum of internal sections of the gas supply mains feeding the assembly and .SIGMA..phi..sub.i represents the sum of the cross-sections of the gas injection apertures of the ducts assembly.

Abstract: Air is distilled in a distillation apparatus (13) associated with a heat exchange line (11) in which is circulated a heat transfer fluid under high pressure. A storage (20, 23) is supplied, at least intermittently, with gas in liquid phase; and gas in liquid phase withdrawn from the storage is raised to a vaporization pressure, and vaporized under this pressure in the heat exchange line (11). The supply of liquefied gas to the storage can be from the distillation apparatus (13) and/or from an external source such as a tank truck (29, 34). It is useful particularly for the supply of oxygen, nitrogen and argon under pressure to installations for the production of stainless steel such as electric arc furnaces.

Abstract: Two electrovalves (7A, 7B) are grouped in a same block (7) and disposed in parallel between a supply conduit (5) and a distribution conduit (6). Each electrovalve is provided with a micrometric adjustment screw (9A, 9B) which can be actuated from outside the block. When one of the electrovalves is in operation to deliver successive identical quantities of liquid, the other electrovalve is adjusted as a function of a new value and, during changeover, it suffices to switch the electrovalves. The same block (7) can contain a third electrovalve (7C) for blowing gas under pressure to expel the remaining drops within the distribution conduit. The liquid and the gas are two phases of the same fluid.

Abstract: A device making it possible to carry out wettability measurements under a controlled atmosphere, comprising an apparatus (5) for measuring the wettability of at least one surface portion of a sample by a liquid metallic solder, at least partially included in an enclosure (6) which includes a gas injector which comprises at least one set of ducts (10) mounted in series and/or in parallel, at least one portion of which includes gas injection orifices, and is fed by at least one gas supply pipe connected to the set at a primary connection node, the dimensioning of the set respecting the following relationship:.SIGMA..omega..sub.i /.SIGMA..phi..sub.i .gtoreq.1 preferably.gtoreq.1.5;where .SIGMA..omega..sub.i represents the sum of the internal cross sections of the gas supply pipes which feed the set and .SIGMA..phi..sub.i represents the sum of the cross sections of the gas injection orifices of the set of ducts.

Abstract: Process and installation for the compression and expansion of at least one gaseous stream, in which a first stream of a gaseous mixture is compressed in a compressor (5) having at least one compression stage (5A, 5B, 5C); a second stream of a gaseous mixture is supercharged in a supercharger (7); a third stream of a gaseous mixture is expanded in an expansion engine (9); at least a portion of the energy generated by the expansion engine is recovered with the supercharger (7) and at least a portion of the second supercharged stream is sent upstream of one stage (5B) of the compressor. The first and second streams are compressed in at least one stage (5A) of the compressor before sending the second stream to the supercharger. The second stream comes from upstream of one stage of the compressor and at least a portion of the supercharged second stream is returned downstream of this stage.