Abstract: A gas-consuming unit (HF) is fed partially by a flow delivered directly by a compression unit (21) and partially by one delivered by a separation apparatus (25) which is itself fed by a flow delivered directly by the compression unit. Another flow produced by the separation apparatus, but at lower pressure, is returned to a compression unit before being sent to the consumer unit.

Abstract: There is provided a unit capable of simultaneously producing nitrogen of ra high purity and oxygen of ultra high purity from air as a feed material. Feed air is introduced into to the bottom 15 of a first rectification column 6. Liquid nitrogen of ultra high purity is recovered from between the upper rectifying part 12 and middle rectifying part 13, and liquid air free of high boiling point components is recovered from between the middle rectifying part 13 and lower rectifying part 14. Oxygen-rich liquid air collected in the bottom 15 is reduced in pressure by an expansion valve 31, and then introduced into a nitrogen condenser 8 as a refrigerant. After a portion of said liquid air is reduced in pressure by an expansion valve 33, it is introduced into the second rectification column 7, where low boiling point components are separated from the top part 21 and liquid oxygen of ultra high purity is recovered from the bottom 23.

Abstract: An air separation plant includes a product nitrogen compressor, a gas turbine and a steam turbine. The gas turbine and the steam turbine are operatively associated with the product nitrogen compressor so as to be able to drive the product nitrogen compressor. The steam turbine has an inlet communicating with a steam generator adapted to recover heat from the gas turbine. The air separation plant also includes an air compressor which is typically similarly operatively associated with a gas turbine and a steam turbine. The steam turbine has an inlet communicating with a steam generator adapted to recover heat from the gas turbine.

Abstract: A blast furnace (1) is supplied with a flow of optionally oxygen-enriched air coming from an isothermal compressor (3) or a (radial) centrifugal compressor (11).

Abstract: An annular column, particularly useful for cryogenic rectification, comprising coaxially oriented, radially spaced cylindrical column walls defining a first column region, and a second column region between the walls, wherein different fluid mixtures are rectified in each of the first column and second column regions.

Abstract: A process for liquefying a gas, wherein the gas is compressed, cooled, then expanded in a first turbine and at least partially liquefied, wherein a portion of the liquid produced is also cooled, and then expanded in a second turbine, wherein the second turbine operates with a higher inlet temperature than the first turbine and the first turbine operates at an outlet pressure different than that from the second turbine.

Abstract: A method of separating air in a liquid nitrogen assist plant in which oxygen rich waste stream produced by the plant is used to partially pressurize adsorbent beds in a pre-purification unit operating in accordance with a pressure swing adsorption cycle.

Abstract: An air separation plant having prefabricated heat exchanger and distillation column sections. The heat exchanger can be used in air expansion, waste expansion and product expansion plants by simply connecting the appropriate piping to the heat exchanger. The air separation unit is built up of standardized sections preferably utilizing structured packing. Simplified liquid distributors and supports are used in order to distribute liquid to the packing and to support the packing within the column, respectfully.

Abstract: Disclosed is a technique which makes it possible to restrain as much as possible the pressure loss, in particular, the pressure of return gas, generated in the main heat exchanger actually used when performing air separation and to reduce the power of the material air compressor as much as possible. In an air separation method of the type in which compressed air cooled through a main heat exchanger is supplied to a lower column of a rectifying tower equipped with upper and lower columns and in which return gas from the upper column of the rectifying tower is passed through the main heat exchanger to utilize it to cool the compressed air, an open end passage is provided in the main heat exchanger, and wherein the return gas is entirely or partly caused to flow through the open end passage, whereby a reduction in the pressure loss of the return gas is achieved.

Abstract: The present invention teaches an efficient and easier to operate distillation embodiment to separate mixtures containing three or more components into streams enriched in one of the components. In this invention, from one end of an earlier distillation column, a liquid or a vapor stream containing two or more components is sent to a subsequent column, then a return vapor or a liquid stream is implemented between the same locations of the two columns. This establishes a two-way communication between one end of the earlier distillation column and the subsequent distillation column. From the other end of the earlier distillation column, a vapor or a liquid stream is eventually fed to another location of the subsequent distillation column; no return stream is implemented between the same locations of the two columns. This establishes the one-way communication between the other end of the earlier distillation column and the subsequent distillation column.

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: A technique is set forth to reduce the heat requirement of conventional distillation processes which separate feed mixtures containing three or more components. The technique provides a great deal of flexibility in adjusting the temperatures of the required utilities including a scenario where the heat requirement is reduced without a need for additional higher temperature (and more costly) heat utility. In this technique, when a liquid bottoms stream (or gaseous overhead stream) containing two or more components is sent from an earlier column to a subsequent column, then a return vapor (or liquid) stream is implemented between the same locations in the two columns.

Abstract: Packing elements with a low pressure drop for mass transfer column internals of the internal diameter of the column and of a height of from 40 to 300 mm made of dimensionally stable layers, which have an ordered structure and are in mutual contact, of cloth material or cloth-like material with a specific surface area of from 100 to 2000 m.sup.2 /m.sup.3, whereina) the shaped layers of cloth material or cloth-like material, preferably made of metal cloth, which are in mutual contact are arranged so that they form a multiplicity of narrow flow channels, preferably virtually triangular, virtually rectangular or else virtually equilateral hexagonal flow channels, in which the angle of inclination of the serration of the individual cloth layers of the packing to the column axis is only 0 to 25.degree., preferably 3 to 14.degree.

Abstract: A cryogenic air separation system wherein separation inefficiencies resulting from feed air flow disturbances due to discontinuous prepurifier operation are reduced or eliminated by inhibiting column liquid drainage during such disturbances using mesh packing having interspacial regions which hold up the liquid during the disturbances using surface tension.

Abstract: An annular column, particularly useful for cryogenic rectification, comprising coaxially oriented, radially spaced cylindrical column walls defining a first column region, and a second column region between the walls, wherein different fluid mixtures are rectified in each of the first column and second column regions.

Abstract: The present invention is an improvement to a nitrogen generator enabling the process to efficiently coproduce oxygen with low recovery, typically less than 70% and preferably less than 55%, in addition to the primary product, nitrogen. In the nitrogen generator process, air is distilled in a distillation column system having a higher pressure column and a lower pressure column. The feed air is compressed, treated to remove water and carbon dioxide, cooled to near its dew point and fed to the higher pressure column of the distillation column system. The nitrogen product is produced by removing an overhead vapor stream from at least one of the columns of the distillation column system. At least one oxygen-enriched stream is removed from the lower pressure column.

Abstract: An activated alumina adsorbent used in a PSA air prepurification process for removal of carbon dioxide from the air is thermally regenerated when the carbon dioxide content remaining in the adsorbent following an adsorbent regeneration step of the PSA process reaches a certain level.

Abstract: Air is separated in a double rectification column including a lower pressure rectification column. A first oxygen product containing less than 3.5% by volume of argon impurity is withdrawn through an outlet of the column which has a packed section below the level of the outlet. The argon impurity is striped from liquid descending through the packed section and a second relatively pure oxygen product containing less than 100 volumes per million is withdrawn from below the section through an outlet thereof. Impurities less volatile than oxygen are preferably separated from the second oxygen product in a side rectification column.

Abstract: A compressor assembly for cryogenic gas separation wherein the assembly comprises a compressor, an expansion turbine and an electric motor integrally connected via a gear drive, and processes for using the compressor assembly.

Abstract: A heat exchange apparatus, typically for use in association with a double rectification column for the separation of air, has a downflow reboiler with boiling passages. In addition, there is a condenser in a position at a higher elevation than the reboiler. The condenser is fed with liquefied gas to be reboiled from the sump of a lower pressure column forming part of the double rectification column. A first conduit feeds the liquefied gas under gravity to the reboiler. The feeding of the condenser is effected by a vapor lift pump comprising a second conduit and an expansion valve disposed therein. Some of the liquefied gas is vaporized by passage through the expansion valve, and this vapor provides the vapor lifting pumping effect. The vapor is recondensed in the condenser.

Abstract: A method for operating a cryogenic rectification column for the separation of the components of air by cryogenic rectification, whereby the column may be operated above its design capacity without encountering flooding, by passing vapor upward through the column at a flowrate which generates a pressure drop within the column of at least 0.7 inches of water per foot of packing height through a height of defined structured packing sheets having a different structure in their upper and lower portions.

Abstract: A method for producing a small amount of oxygen, related to a nitrogen generator unit, is provided. In a nitrogen rectification column which cools down and liquefies feed air after moisture and carbon dioxide contained therein are removed, thereby producing nitrogen, oxygen-rich liquid air is used as a cold source for a nitrogen condenser and the thus-obtained oxygen-rich air is then used as a heating source for a reboiler in an oxygen rectification column.

Abstract: A method for directly producing lower purity oxygen with high recovery, employing a non-adiabatic distillation device within a distillation column to provide high purity liquid nitrogen reflux to the upper section of the column. This invention provides for a variety of feed air options to the non-adiabatic distillation device and to the distillation column.

Abstract: A cryogenic rectification system for producing argon employing an argon stripping column which receives a feed in its upper portion from an associated cryogenic air separation plant, and which is reboiled by another fluid taken from the cryogenic air separation plant.

Abstract: A structured packing is disclosed. The structured packing has a plurality of packing elements stacked together as "building blocks" to provide the packing for an exchange column. Each packing element comprises a polyhedron (e.g., a cube) having a plurality of edges formed by elongated rods. At least one transfer sheet is disposed within the polyhedron (e.g., a cube), wherein the first end of each transfer sheet connects to a different edge of the polyhedron and the second end of each transfer sheet connects to another edge of the polyhedron. In one embodiment, the intersection of the transfer sheets forms two pyramids within the cube-shaped packing element, the bases of the pyramids being opposite sides of the cube and the apices of the pyramids intersecting substantially at the center of the cube. In the preferred embodiment, at least one side of each pyramid is open and the other sides of the pyramids formed by the intersecting transfer sheets provide flow surfaces within the packing element.

Abstract: A single or double dephlegmator is used to transfer heat between condensing nitrogen and rich liquid in a single column nitrogen generator.

Abstract: A cryogenic rectification system for producing oxygen having a feed air preparation system and a plurality of same size cold box modules operating in parallel and in conjunction with the feed air preparation system.

Abstract: Air is separated in a double rectification column comprising a higher pressure rectification column, a lower pressure rectification column and a condenser-reboiler placing the higher pressure rectification column in heat exchange relationship with the lower pressure rectification column. At least one stream of air is introduced into the double rectification column, a stream of pressurized liquid comprising oxygen and nitrogen is reduced in pressure by passage through a valve and is partially or totally vaporized in a vaporizer-condenser, a stream of resulting vapor from the partial or total vaporization is compressed in a compressor at cryogenic temperature and is introduced into the double rectification column, and an oxygen produce is withdrawn from the lower pressure rectification column through an outlet.

Abstract: A liquefied gas mixture comprising at least two components of which one is more volatile than the other or others is boiled in an apparatus including stripping passages for vaporising part of a flow of the mixture. The passages are arranged alternately with condensing passages. The stripping passages each have at least one heat exchange surface which is heated to a temperature which causes the liquid to boil and along which the liquefied gas mixture flows in countercurrent mass exchange relationship with a vapour flow evolved from such liquid. The more volatile component is progressively stripped from the liquefied gas mixture such that the vapour flow is enriched in its direction of flow in the more volatile component and the mixture itself is depleted of the more volatile component in its direction of flow. Accordingly, separation of the mixture takes place in addition to its boiling.

Abstract: A process is set forth for the cryogenic distillation of an air feed to produce at least two oxygen-rich gaseous streams having different oxygen purities. The process uses a mixing column system in addition to a distillation column system. A key to the process is that at least two oxygen-rich liquid streams having different oxygen purities are transferred from the distillation column system to the mixing column system in order to produce the oxygen-rich gaseous streams.

Abstract: A method and apparatus for separating air in which a compressed and purified air stream is cooled in a main heat exchanger. Thereafter, the compressed and purified air is separated in a distillation column system to produce product streams. The product streams warm within the main heat exchanger by indirectly exchanging heat with the compressed and purified air stream. One or more of the product streams is distributed to a plurality of vortex tubes at successively warmer temperatures so that warm and cold streams produced thereby become successively warmer and one or more of the warm streams has a temperature warmer than that of said compressed and purified air stream upon its introduction into said main heat exchanger. All but the warm stream(s) having the warmer temperature are recycled back to said main heat exchanger to participate in the indirect heat exchange and heat is rejected by discharging said warm stream(s) so that heat is rejected at the warmer temperature and refrigeration is produced.

Abstract: A system for achieving a low level of nitrogen in a lower pressure column in the feed to the argon column in a cryogenic air separation system by use of two beds of structured packing of about equal height in the lower pressure column, with mixing and redistribution of liquid between them. The packed beds are located between the feed from the argon column top condenser and the point where the argon column feed is withdrawn.

Abstract: A cryogenic rectification system employing two rectifying sections in parallel within either the lower pressure column of a double column or in a side column, for producing product oxygen at both low and high purity.

Abstract: Air is supplied to an air separation apparatus via a heat exchanger in which the entering air is cooled against an air gas separated in the separation apparatus. The air is first compressed in an adiabatic compressor. The air gas separated in the separation apparatus is humidified after it leaves the separation apparatus but before it reaches the heat exchanger.

Abstract: A heat exchanger for use within a sump to condense an vapor and to vaporize the liquid. The heat exchanger includes a core having alternating passages to vaporize the liquid and to condense the vapor. Liquid is distributed into passages through a liquid distributor and the passages involved in vaporizing the liquid are provided with a down flow, stage and one or more thermosiphon stages situated below the down flow stage. In such manner, part of the liquid is vaporized within the down flow stage and the remainder is vaporized within the thermosiphon stage or stages.

Abstract: A process is set forth for the cryogenic distillation of an air feed to produce nitrogen, particularly high pressure nitrogen of ultra high purity (less than 100 parts per billion of oxygen). A key to the present invention is that, in addition to the conventional reboiler/condenser which links the high and low pressure column, the present invention utilizes two additional reboiler/condensers such that the oxygen rich liquid which collects at the bottom of the low pressure column is reboiled at three different pressure levels.

Abstract: A unit capable of simultaneously producing liquid nitrogen of ultra high purity and liquid oxygen of ultra high purity, is provided. The inside of a first rectification column 6 is demarcated to an upper rectifying part 12, a middle rectifying part 13 and a lower rectifying part 14. To the upper part 11 above the upper rectifying part 12 is connected a nitrogen condenser 8. A second rectification column 7 has a reboiler 24 provided under its rectifying part 22. Ultra high purity liquid nitrogen is recovered from between the upper rectifying part 12 and middle rectifying part 22 of the second rectification column 7, where it is brought in countercurrent contact with gas evaporated by the reboiler 24 provided below the rectifying part 22 so that lower boiling point components are separated therefrom. Thus, ultra high purity liquid oxygen is recovered from below the rectifying part 22 of the second rectification column 7.

Abstract: The present invention provides for a structured packing element, the element being corrugated with corrugations which form alternating peaks and troughs across the element, the corrugations having a longitudinal axis, the element having plural portions of first fluting at an angle between 0.degree. and 180.degree. to the longitudinal axis of the corrugations and plural portions of second fluting at an angle between 0.degree. and 180.degree. to the longitudinal axis of the corrugations, the fluting of the first portions being at an angle greater than zero to the fluting of the second portions, the respective first and second portions alternating both laterally and longitudinally of the element with respect to each other. The element preferably has a plurality of holes through the element. The foregoing structured packing is suited for use in processes requiring a contact device for accomplishing mass and/or heat transfer.

Abstract: A downflow heat exchanger, particularly applicable as the main condenser/reboiler of a double column cryogenic air separation plant, wherein liquid distribution for uniform flow is carried out above the vapor passages and the well distributed liquid is passed into the liquid passages, preferably angularly onto the bridge fins, and then down through the liquid passages cocurrently with vapor in adjacent vapor passages.

Abstract: A liquid-vapor contact apparatus has pairs of vertical outer walls disposed in the manner of the vertical faces of a cuboid. The apparatus includes a plurality of spaced, parallel, vertical plates. Between each pair of adjacent plates there is a packing comprising a vertical array of corrugated liquid-vapor contact elements of the type that are used in structured packing. The corrugations in each element slope from top to bottom in a direction opposed to that in which the corrugations in contiguous elements slope. The two outermost plates form the walls of the apparatus. The walls comprise alternate edge portions of plates and of spacer bars. The plates define first and second sets of passages, respectively. One set of passages performs a first fractionation duty, and the other set another fractionation duty.

Abstract: A liquid-vapour contact apparatus has pairs of vertical outer walls disposed in the manner of the vertical faces of a cuboid. The apparatus includes a plurality of spaced, parallel, vertical plates. Between each pair of adjacent plates there is a packing comprising a vertical array of corrugated liquid-vapour contact elements of the type that are used in the assembly of structured packing, and having the apexes of the elements in fluid tight engagement with the respective plates. The corrugations in each element slope from top to bottom in a direction opposed to that in which the corrugations in contiguous elements slope. The two outermost walls form the walls of the apparatus. The other walls comprise alternate edge portions of plates and of spacer bars. Liquid is distributed appreciably evenly between the passages formed by adjacent vertical plates at the top of the apparatus and flows over the elements and effectively vertically downwards.

Abstract: In a process for liquid evaporation by heat exchange with a gas which condenses, the pressure of the liquid to be evaporated is reduced and it is enriched in a constituent which has little volatility after evaporation. According to an alternative form, the gas to be condensed can be enriched in the constituent which has little volatility.

Abstract: A process is set forth for the cryogenic distillation of an air feed to produce nitrogen, particularly high pressure nitrogen of various purity, varying from low purity (up to 98% nitrogen) to ultra-high purity (less than 1 part per billion of oxygen). The nitrogen may be produced at two different pressures and two different purities. The process uses an auxiliary low pressure separation zone in addition to the conventional high pressure column and low pressure column. The auxiliary low pressure separation zone, which is operated at the same pressure as the low pressure column and which is heat integrated with the top of the high pressure column by means of its bottom reboiler/condenser, pretreats the crude liquid oxygen from the bottom of the high pressure column.

Abstract: Ultra-high purity nitrogen is generated by removing, from feed air, carbon dioxide, moisture and catalyst poisons of an oxidation catalyst contained therein by a decarbonating drier (4). The feed air is then introduced into a low-pressure rectification column (6), where it is roughly rectified to further remove the carbon dioxide, moisture and catalyst poison. Then raw nitrogen gas obtained in the low-pressure rectification column (6) is introduced into an oxidation column (8) so that carbon monoxide in the raw nitrogen gas is converted to carbon dioxide and hydrogen also contained therein to water. Thereafter the raw nitrogen gas is introduced into an adsorption column (10) so that carbon dioxide and water are removed by adsorption to provide feed raw nitrogen gas, which is fed into an intermediate-pressure rectification column (11), where it is rectified.

Abstract: A process is set forth for the cryogenic distillation of an air feed to produce high pressure nitrogen of various purity, varying from moderately high purity (99.9% nitrogen) to ultra-high purity (less than 1 part per billion of oxygen). The process is particularly suited for cases where the high pressure nitrogen is needed directly from the distillation column system to avoid contamination concerns associated with compressing nitrogen that is produced at lower pressures. The process uses a high pressure column, which operates at a pressure to directly produce the nitrogen at the desired high pressure, and one or more lower pressure columns which produces a portion of the nitrogen product at a lower pressure. At least a portion of the lower pressure nitrogen is compressed and fed to the high pressure column at a location which is below the removal location of the high pressure nitrogen.

Abstract: A method for producing ultra high purity liquid oxygen from standard grade liquid oxygen which integrates the oxygen purification process with a nitrogen purification process by utilizing the condensing duty of liquid nitrogen, thereby causing the nitrogen to vaporize which is desirable prior to delivery to a nitrogen purification unit. The method of the present invention includes pressurizing a source of liquid nitrogen and vaporizing at least a portion of the pressurized liquid nitrogen. The resulting high pressure gaseous nitrogen stream is introduced to at least one bottom reboiler/condenser of a high purity liquid oxygen unit, which also purifies standard grade liquid oxygen into ultra high purity liquid oxygen. The gaseous nitrogen provides the needed heat to the distillation columns of the high purity liquid oxygen unit.

Abstract: A cryogenic rectification system employing an additional rectifying section in parallel with the lower section of the lower pressure column of a double column for producing product oxygen at both low and high purity.

Abstract: A heat exchanger is provided which is suitable for use as a condenser/reboiler in a double distillation column. The heat exchanger has alternating first and second passages and a reservoir located above the first and second passages for receiving a first fluid and for containing a froth. A series of orifices can be provided by a distributor tray to provide flow communication between the reservoir and the first passages to allow at least a liquid phase of the froth to weep into the first passages and to be partly vaporized through indirect heat exchange with a second fluid flowing through the second passages. The partial vaporization produces a vapor phase of the froth which can at least in part escape from the orifices and interact with the first fluid to thereby form the froth. A remaining part of the liquid phase, not vaporized through the indirect heat exchange, is discharged from the bottom of the first passages into a sump.

Abstract: The air distillation double column (1,2) includes an apparatus for vaporizing oxygen and condensing nitrogen which comprises on one hand a running type main heat exchanger (7) which is partially immersed during stoppage of the equipment and on the other hand an auxiliary heat exchanger (20) which alone is responsible for liquid vaporization when the equipment is restarted.

Abstract: This column, of the type having a cross-undulating lining, includes means for returning liquid to the vicinity of the edges of the lining and liquid and gas distribution means which contribute to decrease substantially the height of the column. Application to plants for separating gases from air.