Abstract: A cryogenic air separation process and apparatus in a distillation column having a top condenser. Air is compressed, purified and cooled to a temperature suitable for distillation. The air is separated in a distillation column so that an oxygen-enriched liquid and a nitrogen-enriched gas are produced within the column. A stream of cryogenic liquid is sent to the column and an oxygen-enriched liquid is sent from the column to the condenser. The flow rate of cryogenic liquid is regulated as a function of the level of oxygen-enriched liquid at the bottom of the column, and a product stream is withdrawn from the column.

Abstract: A cryogenic air separation system which is subject to periods of significant changes in product demand is controlled during such periods to minimize the impact of transient operation on product purity. The feed air is introduced directly into the higher pressure column of a distillation system having at least two columns, and nitrogen-rich and oxygen-rich vapor products are withdrawn from the lower pressure column. The flow rate of the nitrogen-rich vapor product is controlled as a function of the feed air flow rate by a feed air flow controller which controls the suction pressure of the nitrogen product compressor. The set point of the flow controller is manipulated as a function of the composition of the oxygen-enriched vapor product. A nitrogen-rich liquid is withdrawn from the higher-pressure column and introduced into the lower-pressure column as reflux. An inventory of this liquid is maintained in a holdup tank for storage or withdrawal during periods of transient operation.

Abstract: A method of operating a lower pressure of column of a double distillation column unit. In accordance with the method an ascending vapor phase is initiated within a lower pressure column by vaporizing a descending liquid phase at a column location situated between mass transfer elements and a sump region of the lower pressure column. The liquid phase is vaporized within two or more down-flow reboilers fed with the liquid phase so that the unboiled liquid from one of the down-flow reboilers is fed to another of the down-flow reboilers, thereby to cause vaporization to be distributed between the down-flow reboilers. The down-flow reboilers are configured such that sufficient vaporization occurs to produce a predetermined liquid-vapor ratio at the column location between the transfer elements and the sump without the requirement of recirculating sump liquid to prevent dry out.

Abstract: Up to a certain value (D1) of the demanded flow rate (D), this flow rate is brought to the working pressure and is sent to the consumer pipe. When the demanded flow rate is less than the value (D1), the complement to (D1) is brought to a high pressure, greater than the working pressure, and is sent into a buffer tank. Above the value (D1), the flow rate is supplemented by a flow rate which is drawn from the buffer tank and expanded to the working pressure. The method is useful in supplying oxygen to steel works with electric arc furnaces or to copper refineries.

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 fractionation column has a first vapor inlet to a bottom mass exchange region of the column communicating with a source of vapor mixture to be separated and a second vapor inlet to an intermediate mass exchange region of the column. A valve means is operable to place the second inlet selectively in communication with the source of vapor mixture to be separated. The fractionation column may form part of an air separation apparatus.

Abstract: A method for controlling an integrated cryogenic air separation unit (ASU)/gas turbine system which maintains peak power output in spite of ambient temperature variations. The ratio of air flow to the ASU from a source of supplemental air and a turbine compressor is adjusted to compensate for changes in ambient air temperature and to maintain air flow to the ASU at a level which enables production of the product, a fuel stream is controlled to maintain gaseous output from a combustor at a maximum practical temperature and a flow ratio of waste nitrogen and fuel fed to the combustor is maintained substantially constant.

Abstract: A method of producing gaseous oxygen in accordance with a variable demand cycle in which pumped liquid oxygen from a double column air separation unit is vaporized within a mixing column. During low demand phases, excess liquid oxygen is stored within a storage tank and used to augment the liquid oxygen to vaporized during the high demand phase. Reflux to the lower pressure column of the air separation unit is kept constant by storing liquid with column bottoms produced within the mixing column during the high demand phase for use in the low demand phase when less liquid oxygen is vaporized and therefore less column bottoms is produced in the mixing column.

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 dual capillary inlet cryogenic test chamber having the ability to continuously regulate temperature between about 1.5 K. and 400 K. A controllably heated capillary tube is located in the cryogenic reservoir, spaced from the test chamber and thermally insulated from the cryogen. This capillary tube has a characteristic impedance to fluid flow. A second low temperature, high impedance capillary tube inlet is also in the cryogenic reservoir and is connected between the cryogen reservoir and the test chamber. The combination of a control system with pressure and temperature feedback, combined with the two inlet tubes of different impedance, enables the apparatus to operate continuously and stably at any temperature within its operating range, or to smoothly sweep through any predetermined temperature range.

Abstract: A method for the control of the operation of an installation for the separation of air by cryogenic distillation comprising a double distillation column wherein the top of a medium pressure column and the base of a low pressure column are thermally interconnected by a vaporizer-condenser supplied with liquid oxygen from a bath of liquid oxygen in the base of the low pressure column. Liquid oxygen from the bath is continuously tested to detect the content of nitrous oxide in the bath, and upon the detection of a fall in the nitrous oxide content of the bath when the installation is operating under equilibrium conditions, the flow of liquid oxygen to the vaporizer-condenser is increased to raise the detected nitrous oxide content of the bath. But when the detected nitrous oxide level falls, then either a liquid oxygen purge line is opened farther, or else the operating time or pressure of switching adsorbers in the air supply is changed.

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 and apparatus for recovery of pure argon from air utilize a rectification system comprising at least one air separating column (9) and a pure argon column (25). An argon-enriched mixture (24) of air gases is introduced into the pure argon column (25) in the lower region of which an essentially nitrogen-free argon product (26) is recovered. The head fraction (28) of the pure argon column (25), is liquefied at least partly by indirect heat exchange (29) using the evaporating cooling medium (11, 30). The condensate (28a) formed thereby is returned into the pure argon column. The indirect heat exchange (29) is carried out by means of a cooling medium (11, 30) which has an oxygen content of at least 10%. Independently thereof, the lower region of the pure argon column (25) is heated by indirect heat exchange (27) by means of a heating medium (11) in a liquid state, for example, with sump liquid from a pressure column (8).

Abstract: A system which integrates a cryogenic air separation plant with a blast furnace system enabling efficient oxygen enrichment of the blast air, and, if desired, production of additional higher purity oxygen.

Abstract: Process and installation for the production of variable flow rates of at least one pure component by fractionation of a mixture in a distillation apparatus (15), containing structured packing (17) and dimensioned to handle a nominal flow rate of the mixture at nominal pressure. To obtain higher production than the nominal production, there is increased proportionately to the ratio of the productions, the flow rate of the mixture distilled in the apparatus (15). Also increased is the operating pressure of the apparatus so as to increase the flooding limit of the apparatus under similar proportions. Preferably, the mixture is air. There is a compressor (3) for the mixture to be fractionated designed for nominal capacity and, upstream of the latter, a blower (1). Alternatively, there can be a compressor (3) for the mixture to be fractionated designed for maximum capacity.

Abstract: A cryogenic air separation process generates both an intermediate product and an output product. The intermediate product is produced earlier in time than the output product and variations in output product measurements correlate to earlier variations in intermediate product measurements. The process responds to plural independent variable phenomena. The apparatus includes analyzers for providing measures of the intermediate and output products and the independent variable phenomena. A control processor predicts a measure of the intermediate product, based on the independent variable phenomena and output predicted values therefor. A difference is then determined between the current predicted value for the intermediate product and a measure of the intermediate product, to arrive at a prediction error.