Abstract: An exchanger comprises a plurality of plates (8) made of copper, nickel or aluminium or an alloy of these metals, which are separated by exchange corrugations made of copper or a copper alloy (6) and two outer sheets (7). The distance between the plates is more than 6 mm, optionally 8 mm.

Abstract: A film-type vaporizer (2) in a vaporization enclosure (1), for example the upper column of a double air-distillation column, is associated with a measurement and analysis box (3) where a polished surface (4) and a spillway (6) reconstruct the flow of liquid in the vaporizer in order to check for the absence of the deposition of impurities in the liquid that is to be evaporated or, if such a deposition occurs, to quantify and analyse the impurities involved and take appropriate action on the settings of the machine.

Abstract: A film-type vaporizer in a vaporization enclosure, for example the upper column of a double air-distillation column, is associated with a measurement and analysis box where a polished surface and a spillway reconstruct the flow of liquid in the vaporizer in order to check for the absence of the deposition of impurities in the liquid that is to be evaporated. If deposition occurs, the impurities involved are quantified and analyzed and appropriate action taken on the settings of the machine.

Abstract: A fin (9) includes a perforated and/or recessed corrugated product which has a main direction of corrugation (F1) and which is bounded by two lateral edges (13). The main direction of corrugation (F1) is oblique with respect to the two lateral edges (13). The fin is useful in the main heat-exchange lines of air distillation plants.

Abstract: Column for the cryogenic separation of gaseous mixtures comprising:

Abstract: Provided is a process for measuring the amount of impurities in a gas sample filling a laser absorption spectroscopy analysis cell. The process includes calculating the value of a characteristic representative of the absorbance of the gas sample, from a measurement of the gas sample at a single given pressure, and quantifying the impurities on the basis of a predetermined law for the variation of the characteristic as a function of the amount of impurities. The characteristic is the ratio of the difference between the luminous intensity (Iana) of a light beam transmitted through the gas and the luminous intensity (Iref) of the incident beam to the luminous intensity (Iref) of the incident beam. The impurities are quantified on the basis of a value of the coefficient of proportionality between the amount of impurities and the characteristic, determined on the basis of a table of variation of the characteristic as a function of pressure, for a given amount of impurities.

Abstract: The invention relates to a process for the manufacture of improved active charcoal exhibiting a high resistance to sulphur-comprising products, such as H2S, COS and mercaptans; to the improved active charcoal thus obtained; and to a process for the purification of a gas stream comprising sulphur-comprising compounds. The gas to be treated is air, nitrogen, hydrogen produced by reforming or cracking of alcohols, of ammonia or of hydrocarbons, natural gas, combustion gas or fermentation gas.

Abstract: In an air separation apparatus comprising at least two columns (104, 105) and optionally a mixing column (107), a liquid containing between 22 and 70 mol % oxygen is vaporized in a reboiler/condenser (109) against a stream of air (86) which condenses therein at least partially. The stream of at least partially condensed air is sent to at least one column (104, 105, 107) of the column system.

Abstract: A liquid distributor includes a principal container with a perforated bottom, as well as transport members to transmit, by gravity, the liquid from at least one opening in the perforated bottom, to a supply point not in vertical alignment with this opening.

Abstract: Process for separating nitrogen from a gas mixture containing nitrogen and at least one gas which is less polar than nitrogen, and employing a differential gas adsorption technique, called PSA process, using an adsorbent of zeolite type, according to which the PSA process is used at a temperature of at least 40° C. by employing as adsorbent a zeolite whose nitrogen adsorption isotherm at 20° C.

Abstract: This device comprises a closed heating chamber (36) extending through the wall (3, 4, 5) of the tank and connected to this wall, a feed pipe (22) suitable for feeding the heating chamber (36) with a heating fluid having a temperature above the temperature of the cryogenic fluid, and an exhaust pipe (23) intended for discharging the heating fluid, each of the pipes intended for discharging the heating fluid, each of the pipes (22, 23) passing through an outer wall (20) of the heating chamber (36). The device is particularly useful in the delivery of ultrapure helium.

Abstract: Process and unit for the arc working, particularly plasma cutting, of a workpiece, in which a plasma torch is supplied with an electric current and with a gas mixture containing hydrogen and nitrogen and/or argon, and a plasma jet obtained by the ionization of the gas mixture by the electric current is delivered by means of the plasma torch. The hydrogen concentration in the gas mixture containing hydrogen and nitrogen and/or argon is less than 50%. The gas mixture is obtained by adding a defined amount of hydrogen to nitrogen and/or argon, immediately before the gas mixture is introduced into said torch. The defined amount of hydrogen is defined according to the thickness of the workpiece, to the grade of the constituent material of the workpiece, to the desired work rate and/or to the intensity of the electric current.

Abstract: Installation for analyzing the level of at least one element, from at least two initial gas sources (S1, S2, . . . ) in a sampling procedure, using at least one analyzer (A1, A2, . . . ) capable of analyzing the element, including: at least two sources (S1, S2, . . . ) of initial gases to be analyzed; at least two tapping lines (Lp1, Lp2, . . . ), each line being connected in its upstream part to one of the initial gas sources, and in its downstream part to a respective flow-directing component (V1, V2. . . ); at least two discharge lines (LE1, LE2, . . . ), each discharge line being connected in its upstream part to one of the directing components and in its downstream part to a discharge or to a storage point (E1, E2, . . . ); at least two secondary lines (Ls1, Ls2, . . .

Abstract: A PSA, especially VSA, plant for separating a gas stream, operating in a production cycle and comprising at least one adsorber, preferably two or three adsorbers, and several valves having long and heterogeneous operating times. More specifically, the average operating time (&mgr;) of the valves is such that: 0.5 s<&mgr;<2 s and the operating time (&Dgr;t) of each of the valves is such that: &mgr;−x<&Dgr;t<&mgr;+x, with 0.1 s<x<0.5 s. The invention also relates to the use of such a PSA plant for producing a gas stream rich in oxygen, in nitrogen or in hydrogen, particularly a stream comprising more than 80% oxygen, which is then sent to an oxygen-consuming plant chosen from a combustion furnace, a paper-pulp manufacturing unit and a water treatment unit.

Abstract: Provided is a process for the manufacture of technical glass. The process includes, heating a glass bath with at least one flame, wherein the at least one flame is a non-hard flame which is blue in color and includes substantially no reducing species.

Abstract: A PSA, especially VSA, process for separating a stream of gas, such as air, containing at least one first compound, such as nitrogen, which is preferentially adsorbed on at least one adsorbent and at least one second compound, such as oxygen, which is adsorbed less preferentially on the adsorbent than the first compound. The adsorbent comprises at least particles of a zeolite having a Si/Al ratio of less than or equal to 5 and chosen from zeolites of X or A type, the zeolite having a kinetics coefficient (ak) and an intrinsic strength (&agr;), with: ak>0.5 s−1 and 0.10<&agr;<2. The invention also relates to an adsorbent for the non-cryogenic separation of gases, especially the gases from air and from syngas.

Abstract: The treatment of a food product is carried out using ozonized water in at least two containers, each container possibly being associated with a set value of the dissolved-ozone content that it is desirable to maintain therein, by ozonizing a stream of water so as to obtain a dissolved-ozone content of the stream of ozonized water greater than or equal to the highest of the set values of the dissolved-ozone content which are associated with each of said containers, and the dissolved-ozone content in each of the solution containers is analyzed in order to compare the result of each of the analyses with the associated set value and to carry out a feedback operation, where appropriate, depending on the result of each comparison, on the control of the flow of ozonized water injected into the container in question, so as to reestablish the dissolved-ozone content of this solution container at its associated set value.

Abstract: Provided is a novel method of and system for recovering and recirculating a deuterium-containing gas. According to the inventive method, a deuterium-containing feed gas is introduced into a chamber. An exhaust gas containing deuterium is removed from the chamber. The deuterium concentration of the exhaust gas is adjusted to a predetermined value, thereby producing a concentration-adjusted gas stream. Finally, the concentration-adjusted gas stream is introduced into the chamber as the deuterium-containing feed gas. The invention makes the use of deuterium, for example, in the mass production of semiconductor devices, commercially feasible.

Abstract: Process for partial oxidation in a Claus furnace of at least one gas stream having hydrogen sulphide, and including the steps of: (a) injecting at least one gas stream including hydrogen sulphide and at least one oxygen-enriched gas stream into the Claus furnace, wherein each of the streams is injected at a speed of injection which is substantially parallel, and (b) controlling the speed of injection of the gas stream including hydrogen sulphide and the speed of injection of the oxygen-enriched gas stream such that the speeds have a ratio between 0.8 and 1.2.

Abstract: Hybrid welding process and unit for welding metal workpieces, such as tailored blanks, by using a laser beam and an electric arc, preferably a plasma arc, in which process, after a welded joint has been produced, the laser beam is sent and/or deflected into radiation absorption means, such as an absorption cavity, allowing the radiation of the said beam to be absorbed. The beam continues to be deflected during the welding stop phase after producing one welded joint and before starting to weld a second welded joint. The process and the unit of the invention are particularly suitable for the mass production of workpieces for the motor-vehicle industry, such as tailored blanks that can be used to manufacture, for example, motor-vehicle body components, or for the mass production of pipes.