Column Patents (Class 62/905)

Cross-Reference Art Collections

Packing (Class 62/906)
  • Patent number: 8448463
    Abstract: The present invention provides a method of rectifying an oxygen, nitrogen and argon containing feed stream that employs high and low pressure columns and an argon column. Refrigeration is imparted through turboexpansion of a nitrogen-rich vapor stream withdrawn from the high pressure column. The nitrogen-rich vapor stream has a sufficiently high flow rate that the flow of both vapor and liquid within the low pressure column is decreased to such an extent that the diameter of the low pressure column can be made substantially equal to or less than that of the high pressure column. The use of the argon column allows recovery of the oxygen to be increased over that which would otherwise be obtained given the draw of the nitrogen-rich vapor. The argon column can be an argon rejection column in which the separated argon is discarded as waste.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: May 28, 2013
    Assignee: Praxair Technology, Inc.
    Inventors: Neil Mark Prosser, Wei Zhang
  • Patent number: 8408026
    Abstract: An apparatus for collecting/redistributing a flow of liquid descending in an exchange column containing a layer of packing that includes: a plurality of horizontally spaced longitudinal members, each member having an inner side and an upper end adjacent a bottom of the layer of packing; at least one plate vertically spaced from the bottom of the layer of packing, each plate adapted to collect a portion of the flow of the descending liquid and having opposing ends connected to the inner sides of a pair of the longitudinal members; and at least one vapor riser in fluid communication with the plate and adapted to receive and transmit at least a portion of a stream of a vapor ascending in the exchange column from below to above the plate, each vapor riser having a cap vertically spaced apart from the bottom of the layer of packing.
    Type: Grant
    Filed: August 21, 2007
    Date of Patent: April 2, 2013
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Kenneth William Kovak, Clive Chalk, Stephen Graham Sawyer
  • Patent number: 7954339
    Abstract: An apparatus for the cryogenic distillation of air includes an assembled unit that has a first distillation column module within which is provided a cryogenic distillation column; a heat exchange module within which is provided heat exchange means for cooling column feed air to a cryogenic distillation temperature; and at least one further processing unit. The or each distillation column, the heat exchange means, and the or each further processing unit are operationally interconnected, and the assembled unit is suitable for transportation to and erection at the site for a cryogenic air separation plant. Construction of a cryogenic air distillation plant is simplified resulting in a reduction in construction cost and time of construction. In addition, as components of the apparatus are self-contained within modules, the risk of contamination of the internal components is reduced, thus improving control of the quality of the construction.
    Type: Grant
    Filed: March 29, 2004
    Date of Patent: June 7, 2011
    Assignee: Air Products & Chemicals, Inc.
    Inventor: Stephen John Gibbon
  • Patent number: 7263858
    Abstract: The present invention provides generally a method and apparatus for purifying a liquid. More particularly, purification of a bulk liquid is performed by introducing a liquid stream to a purification vessel, which comprises both a distillation chamber for forming a purified vapor and an annular chamber for collecting a purified liquid that is condensed from the purified vapor. A refrigerant system provides thermodynamic efficiency in the purification method by directing waste heat generated in one part of the refrigerant system for heating duty in another part of the refrigerant system. The method and apparatus can be applied to producing purified carbon dioxide, nitrous oxide, ammonia and fluorocarbons.
    Type: Grant
    Filed: May 20, 2005
    Date of Patent: September 4, 2007
    Assignee: The BOC Group, Inc.
    Inventor: Walter Whitlock
  • Patent number: 6948337
    Abstract: The invention relates to a low temperature air fractionation system comprising several modules consisting of at least one heat exchange unit, a pressure column and a low pressure column, in addition to the accessories belonging to the respective modules and at least two cold-boxes, wherein the module and/or the accessories are arranged. The invention is characterized in that at least one of the cold-boxes is embodied in the form of a main box and at least one of the cold-boxes is embodied in the form of a secondary box. The secondary box contains at least one module and the accessories of the module disposed in the secondary box are mainly located in the main box.
    Type: Grant
    Filed: August 13, 2001
    Date of Patent: September 27, 2005
    Assignee: Linde AG
    Inventors: Stefan Moeller, Wolfgang Bader
  • Patent number: 6912872
    Abstract: The present invention provides generally a method and apparatus for purifying a liquid. More particularly, purification of a bulk liquid is performed by introducing a liquid stream to a purification vessel, which comprises both a distillation chamber for forming a purified vapor and an annular chamber for collecting a purified liquid that is condensed from the purified vapor. A refrigerant system provides thermodynamic efficiency in the purification method by directing waste heat generated in one part of the refrigerant system for heating duty in another part of the refrigerant system. The method and apparatus can be applied to producing purified carbon dioxide, nitrous oxide, ammonia and fluorocarbons.
    Type: Grant
    Filed: August 23, 2002
    Date of Patent: July 5, 2005
    Assignee: The BOC Group, Inc.
    Inventor: Walter H. Whitlock
  • Patent number: 6907751
    Abstract: Liquid is distributed substantially uniformly in a liquid-vapour separation column 22 located on an off-shore floating platform using a liquid distributor 24 characterised in that (i) the distance between the two apertures that are furthest apart in the or each secondary distributor is such that the liquid distributor provides, at each angle of tilt, a standard deviation of liquid flow rates through the apertures of the or each secondary distributor that is less than a first predetermined maximum for all angles of tilt; and (ii) the difference in flow rate between the aperture having maximum liquid flow and the aperture having minimum liquid flow in the or each secondary distributor at each angle of tilt is less than a second predetermined maximum for all angles of tilt.
    Type: Grant
    Filed: July 14, 2003
    Date of Patent: June 21, 2005
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Mohammad A. Kalbassi, Ian R. Zone
  • Publication number: 20040237582
    Abstract: The invention relates to a process for producing oxygen or air enriched with oxygen, in which process: The air entering the process is cooled in a heat exchanger to near to the condensation point of air and the air is led to a separation unit formed of two or more chambers connected thermally to each other and comprising A and B halves, in which it is divided, using liquidization and evaporation processes, into two or more gaseous fractions. The process air is maintained at normal temperature, except for small pressure differences to maintain the flow of the air and to optimize the process.
    Type: Application
    Filed: April 7, 2004
    Publication date: December 2, 2004
    Inventor: Matti Nurmia
  • Publication number: 20040020238
    Abstract: Liquid is distributed substantially uniformly in a liquid-vapour separation column 22 located on an off-shore floating platform using a liquid distributor 24 characterised in that (i) the distance between the two apertures that are furthest apart in the or each secondary distributor is such that the liquid distributor provides, at each angle of tilt, a standard deviation of liquid flow rates through the apertures of the or each secondary distributor that is less than a first predetermined maximum for all angles of tilt; and (ii) the difference in flow rate between the aperture having maximum liquid flow and the aperture having minimum liquid flow in the or each secondary distributor at each angle of tilt is less than a second predetermined maximum for all angles of tilt.
    Type: Application
    Filed: July 14, 2003
    Publication date: February 5, 2004
    Inventors: Mohammad A. Kalbassi, Ian R. Zone
  • Patent number: 6662594
    Abstract: An apparatus and process for producing gaseous oxygen under elevated pressure utilize a distillation column system which has a high-pressure column (106), a low-pressure column (107) located above the high-pressure column (106), and a side condenser (102), which has a liquefaction space and a vaporization space, used to vaporize a liquid oxygen fraction from the low-pressure column (107). The side condenser (102) is located below the high-pressure column (106).
    Type: Grant
    Filed: December 16, 2002
    Date of Patent: December 16, 2003
    Assignee: Linde Aktiengesellschaft
    Inventors: Augustin Rampp, Michael Lauter
  • Patent number: 6543252
    Abstract: The invention relates to a vaporizer-condensor (4) of the bath type, comprising at least one heat exchange body (13), having a multitude of flat passages (18) for the countercurrent circulation of two fluids in a same direction, and a sealed chamber (14) for confining a fluid containing the or each heat exchange body, the confinement chamber comprising a central section (50) of generally cylindrical shape along a longitudinal axis (Y—Y). The longitudinal axis of the central section of said or each confinement chamber is orthogonal to the direction of countercurrent circulation of the fluids in the flat passages of the corresponding heat exchange body. Use in double column air distillation installations.
    Type: Grant
    Filed: August 10, 2000
    Date of Patent: April 8, 2003
    Assignee: L'Air Liquide - Societe Anonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Francois Fuentes, Marc Wagner, Claude Gerard
  • Patent number: 6536233
    Abstract: A mixture containing oxygen is introduced into a distillation column (1); an intermediate stream, substantially free from impurities heavier than oxygen, is withdrawn (at 17) at a level of the column located above the point (4) of introduction of the air, the point (22) of withdrawal being separated from this point (4) of introduction by a distillation section (6), particularly with packing; the stream withdrawn (at 17) is sent to an oxygen purification column (2), and a reflux liquid is distributed over the section (6) by a distributor (9). A predetermined non-uniformity of the distribution of the reflux liquid over the upper surface (8) of the section (6) is effected in at least one localized region (23) of this surface.
    Type: Grant
    Filed: March 15, 2002
    Date of Patent: March 25, 2003
    Assignee: L'Air Liquide - Societe Anonyme a Directoire et Conseil de Surveillance pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Bernard Darredeau, Alain Briglia
  • Patent number: 6378332
    Abstract: A corrugated structured packing for forming into modules for use in a rectification column, having both high and low corrugations which reduce the contact points when formed into modules, serving to improve mass transfer effectiveness and thus reduce the requisite column height.
    Type: Grant
    Filed: September 7, 2000
    Date of Patent: April 30, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: John Fredric Billingham, Michael James Lockett
  • Patent number: 6351968
    Abstract: The process and the apparatus serve for evaporating liquid oxygen. In the normal operation liquid oxygen is introduced into a main evaporator (3) and there partially evaporated, a first flushing stream (5) is removed in the liquid state from the main evaporator (3), the first flushing stream (5) is partially evaporated in an auxiliary evaporator (6) and a second flushing stream (7) is taken off in the liquid state from the auxiliary evaporator (6). The normal operation is interrupted by a heating operation in which no liquid (5) is passed from the main evaporator (3) into the auxiliary evaporator (6) and the auxiliary evaporator (6) is brought to a temperature which is markedly higher than its temperature in the normal operation.
    Type: Grant
    Filed: July 28, 2000
    Date of Patent: March 5, 2002
    Assignee: Linde Aktiengesellschaft
    Inventors: Franz Habicht, Gerhard Pompl
  • Patent number: 6347533
    Abstract: A fully thermally coupled distillation structure designed to overcome hydraulic limitations in the past has been revealed for separating a multi-component feed stream into three product streams. The fractionation apparatus is equipped with at least one condenser and one reboiler to provide fractionation efficiency surpassing the PETLYUK system. Further, the fractionation apparatus includes innovative designs to enable hydraulically balanced and energy efficient operation at various feed rates, compositions and product specifications.
    Type: Grant
    Filed: March 4, 2000
    Date of Patent: February 19, 2002
    Inventor: Peter Tung
  • Publication number: 20020017111
    Abstract: A distillation apparatus comprises a reboiler/condenser (30), cleanable in operation, being duplicated by another reboiler/condenser (40).
    Type: Application
    Filed: December 26, 2000
    Publication date: February 14, 2002
    Inventors: Francois Fuentes, Marc Wagner
  • Publication number: 20010018829
    Abstract: Apparatuses which, in steady-state operation, are at temperatures very different from ambient temperature, are each supported by a base support device, or are secured by a separating support device, and are linked by a pipe device. In order to reduce the mechanical stresses on the pipe device, at least two components of the structure among the support devices and the pipe device are made of different materials having an expansion coefficient and/or a thermal conductivity coefficient which are different so that when the plant goes from inactivity at ambient temperature to steady-state operation the variations in length of the components made of different materials are concomitant. Such structures are usable in air distillation plants.
    Type: Application
    Filed: February 21, 2001
    Publication date: September 6, 2001
    Applicant: L'Air Liquide, Societe Anonyme
    Inventor: Marc Wagner
  • Patent number: 6250106
    Abstract: A process uses a multizone distillation column for the separation of a multicomponent feed into one stream enriched in the most volatile component, one stream enriched in the least volatile component, and at least two other streams enriched in a component of intermediate volatility. The multizone distillation column has at least two vertical partitions, thereby creating a primary distillation zone and at least two secondary distillation zones. Each of the secondary distillation zones is fed with a mixture from another distillation zone, and a product stream enriched in a component of intermediate volatility is produced from each of the secondary distillation zones. At least one secondary distillation zone receives either at least a portion of the vapor boilup or a portion of the liquid reflux from a source external to the multizone distillation column or through heat exchange with a utility source that is external to the multizone distillation column.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: June 26, 2001
    Assignee: Air Products and Chemicals, Inc.
    Inventor: Rakesh Agrawal
  • Patent number: 6240744
    Abstract: A process separates a multicomponent feed by distillation into at least one stream enriched in the most volatile component, one stream enriched in the least volatile component, and one stream enriched in a component of intermediate volatility. In one embodiment, the process produces an argon-enriched stream from a cryogenic air separation process. The distillation system includes at least one distillation column that produces a nitrogen-enriched stream from the top of the column, an oxygen product stream from the bottom of the column, and an argon-enriched stream from a partitioned section. The geometry of the partitioned section minimizes vapor and liquid distribution, and includes a vertical separating element and an end separating element to isolate the partitioned section from the intermediate distillation section.
    Type: Grant
    Filed: December 13, 1999
    Date of Patent: June 5, 2001
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Rakesh Agrawal, Donn Michael Herron, Jung Soo Choe
  • Patent number: 6212891
    Abstract: Process components, containers, and pipes are provided that are constructed from ultra-high strength, low alloy steels containing less than 9 wt % nickel and having tensile strengths greater than 830 MPa (120 ksi) and DBTTs lower than about −73° C. (−100° F.).
    Type: Grant
    Filed: June 18, 1998
    Date of Patent: April 10, 2001
    Assignee: ExxonMobil Upstream Research Company
    Inventors: Moses Minta, Lonny R. Kelley, Bruce T. Kelley, E. Lawrence Kimble, James R. Rigby, Robert E. Steele
  • Patent number: 6205815
    Abstract: A plant for separation of a gas mixture comprises at least two columns which are of the same length. The tops of two of the columns are at the same height.
    Type: Grant
    Filed: May 15, 2000
    Date of Patent: March 27, 2001
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Olivier Bruder, Bernard Darredeau, Jean-Yves Lehman
  • Patent number: 6173586
    Abstract: A cryogenic air separation system for producing very high purity oxygen employing a lower pressure column having a volume in its lower portion set off by a diaphragm, and an upgrader column communicating with the lower pressure column in a defined manner relative to the diaphragm.
    Type: Grant
    Filed: August 31, 1999
    Date of Patent: January 16, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Dante Patrick Bonaquist, John Fredric Billingham
  • Patent number: 6167723
    Abstract: In this installation (1) for the distillation of air in a double column, the low pressure column and the medium pressure column are disposed side by side and the base of the low pressure column (3) is above the base of the medium pressure column (2). The low pressure column is disposed above an element for confining a cryogenic fluid which can be a mixing column (5), an argon column, a column operating at a pressure intermediate the medium pressure and the low pressure, a storage (32) or an exchanger.
    Type: Grant
    Filed: April 30, 1999
    Date of Patent: January 2, 2001
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventor: Alain Guillard
  • Patent number: 6155078
    Abstract: In an air distillation apparatus having a main heat exchanger 7 for cooling down feed air, a rectification column 9S comprising a rectifying portion 13 for separating the thus-cooled feed air to an oxygen-enriched component and a nitrogen component and a condenser 35S for partially condensing the latter, and a liquid nitrogen storage tank 31S for supplying liquid nitrogen by way of a supply valve V3, anda transport route 18 for transporting an oxygen-enriched liquid flowing down from said rectifying portion 13 to the bottom into said condenser 35S, the said oxygen-enriched liquid is not reserved at the bottom of the column.
    Type: Grant
    Filed: August 20, 1998
    Date of Patent: December 5, 2000
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Kazuhiko Miyashita, Tadatoshi Aida
  • Patent number: 6148637
    Abstract: The plant (1) comprises at least three assemblies (10, 11, 12) arranged one beside the other, namely a first assembly (10) comprising a medium-pressure column (2), a second assembly (11) comprising a low-pressure column (3), and a third assembly (12) comprising a heat-exchange line (5). The plant further comprises a liquid pump (6) for making a liquid flow between one of the columns (3) and the vaporizer-condenser (4). Application to the distilling of air using columns with structured interior packing.
    Type: Grant
    Filed: February 8, 1999
    Date of Patent: November 21, 2000
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventors: Alain Guillard, Patrick Le Bot, Jean-Marc Tsevery, Gilles Bracque, Benoit Rousseau
  • Patent number: 6134915
    Abstract: A packaged column arrangement for an air separation plant in which a cold box is filled with an insulating material and higher and lower pressure columns are mounted within the cold box. The lower pressure column has an intermediate reboiler connected to the higher pressure column for condensing nitrogen enriched tower overhead formed within the higher pressure column in order to produce reflux for the columns. The higher and lower pressure columns are positioned within the cold box so that the higher and lower pressure columns are in a sufficiently staggered relationship that the reflux stream to the higher pressure column flows under gravitational influence. Moreover, auxiliary equipment such as vaporizer and subcooling heat exchange units can be conveniently connected to the columns when themselves may be mounted within the cold box by a simple I-beam mounting.
    Type: Grant
    Filed: March 30, 1999
    Date of Patent: October 24, 2000
    Assignee: The BOC Group, Inc.
    Inventors: Arthur R. Denzau, Andrew B. McKenzie
  • Patent number: 6101840
    Abstract: The air separation plant is provided with a housing for containing cryogenic equipments, at least one free-standing column to be disposed in the housing, at least one column to be disposed in the housing on a frame constituting the housing, and a powdery thermal insulator packed in the housing, having a packing density to be obtained by packing under atmospheric pressure; the free-standing column being set to have a first natural frequency of not more than 0.7 times or not less than 1.0 times as large as that of the housing. Further, the packing density of the powdery thermal insulator is 55 to 80 kg/m.sup.3.
    Type: Grant
    Filed: May 4, 1998
    Date of Patent: August 15, 2000
    Assignee: Nippon Sanso Corporation
    Inventors: Akimasa Watanabe, Kazushige Arai
  • Patent number: 6023945
    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.
    Type: Grant
    Filed: June 11, 1999
    Date of Patent: February 15, 2000
    Assignee: Praxair Technology, Inc.
    Inventors: Kenneth Kai Wong, John Frederic Billingham, Dante Patrick Bonaquist, Bayram Arman, Raymond Francis Drnevich, Minish Mahendra Shah, Todd Alan Skare
  • Patent number: 5946942
    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.
    Type: Grant
    Filed: August 5, 1998
    Date of Patent: September 7, 1999
    Assignee: Praxair Technology, Inc.
    Inventors: Kenneth Kai Wong, John Frederic Billingham, Dante Patrick Bonaquist, Bayram Arman, Raymond Francis Drnevich, Minish Mahendra Shah, Todd Alan Skare
  • Patent number: 5802858
    Abstract: A cryogenic cooling tower in which a process liquid from which heat is to be removed is supplied to the tower interior that has a plurality of plates vertically stacked one above the other, alternating in opposite directions and tilted downwardly at an angle relative to the tower vertical axis. A cryogenic cooling medium is supplied to the tower interior. The process liquid forms a film on the upper surface of the plate and drops from its front end to the next lower plate. While on a plate the process liquid spread into a film provides a greater surface area to react with the cooling medium to effect the heat transfer. The tilt angle of the plates can be adjusted to control the residence time of the process liquid in the tower.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: September 8, 1998
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Donald Leonard Devack
  • Patent number: 5735141
    Abstract: A method and apparatus for purifying a substance in which the substance is rectified within first and second distillation columns to produce a tower overhead in the second distillation column, lean in both heavy and light impurities. The column bottoms produced within the second distillation columns is boiled to provide boil-up within the second distillation column, thereby to initiate formation of an ascending vapor phase. A vapor stream in removed from the second distillation and then fed into a bottom region of the first distillation column to initiate formation of the ascending vapor phase therein. The vapor stream removed from the second distillation column is formed from the ascending vapor phase produced within the second distillation column. The second distillation column is reboiled by a reboiler that can include a reservoir containing a heat exchange fluid that condenses against boiling the column bottoms provided in the second distillation column.
    Type: Grant
    Filed: January 10, 1997
    Date of Patent: April 7, 1998
    Assignee: The BOC Group, Inc.
    Inventor: Walter H. Whitlock
  • Patent number: 5730002
    Abstract: A gas containing at least two constituents A and B having different temperatures is fractionated by carrying out at least the two cooling and contacting phases as follows:a) during a first stage, said gas is at least partly cooled to cause condensation of at least a first liquid fraction and said gas is brought into contact with said liquid fraction in at least a first zone of contact and heat exchange Z1, and at least a liquid fraction enriched in constituent A and at least a gaseous fraction are collected at the outlet of said first zone of contact and heat exchange Z1,b) during a second stage, said gaseous fraction from stage a) is at least partly cooled to cause condensation of at least a second liquid fraction and said gaseous fraction is brought into contact with said second liquid fraction in at least a second zone of contact and heat exchange Z2, and at least a liquid fraction enriched in constituent B and at least a gaseous fraction are collected at the outlet of said second zone.
    Type: Grant
    Filed: October 11, 1996
    Date of Patent: March 24, 1998
    Assignee: Institut Francais du Petrole
    Inventors: Jean-Claude Collin, Alexandre Rojey
  • Patent number: 5704228
    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.
    Type: Grant
    Filed: March 15, 1996
    Date of Patent: January 6, 1998
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventor: Jean-Pierre Tranier
  • Patent number: 5666824
    Abstract: A double column cryogenic rectification system for producing lower purity oxygen wherein a minor portion of the feed air is successively condensed in two vertically oriented stages within the lower pressure column before undergoing rectification.
    Type: Grant
    Filed: March 19, 1996
    Date of Patent: September 16, 1997
    Assignee: Praxair Technology, Inc.
    Inventor: Dante Patrick Bonaquist
  • Patent number: 5649433
    Abstract: An improved cryogenic liquefied gas container, or a so-called cold evaporator (CE) for containing a plurality of different liquefied gases such as oxygen and nitrogen gases can be installed on a site with a limited surface area and can store the gases at a substantially equal and constant temperature level to ensure a stable gas supply to consumers that may include medical facilities and manufacturing plants. A plurality of inner tanks 4 are vertically arranged and surrounded by an insulation layer 3 in an outer shell 2 in order to economically utilize the site. The temperature of the high boiling point liquefied gas LG1 contained in the upper inner tank 4a and hence the internal pressure of the upper inner tank are stabilized by means of a heat exchanger section 11 to which the low boiling point liquefied gas LG.sub.
    Type: Grant
    Filed: April 30, 1996
    Date of Patent: July 22, 1997
    Assignee: Daido Hoxan Inc.
    Inventors: Hiroaki Suzuki, Yuji Morimoto, Yasuo Tanaka, Taturu Yamauchi
  • Patent number: 5617740
    Abstract: A method and unit for easily and continuously producing high pressure gaseous monosilane and high pressure liquid monosilane, each having an ultra high purity. In the ultra high purity monosilane producing method, a feed monosilane gas is pressurized, cooled down and subjected to a gas-liquid phase separation. The separated gas phase is introduced to a lower rectification column 1 so as to be rectified. The gas obtained through this rectification is introduced to an upper rectification column 2 so as to be rectified, wherein a gaseous monosilane product or liquid monosilane product having an ultra high purity is taken out of the bottom portion of the upper rectification column.
    Type: Grant
    Filed: December 27, 1995
    Date of Patent: April 8, 1997
    Assignee: L'air Liquide, Societe Anonyme Pour L'Etude Et L'Exploitation Des Procedes Georges Claude
    Inventors: Takashi Nagamura, Shinji Tomita
  • Patent number: 5590543
    Abstract: The present invention relates to an improvement to cryogenic air separation processes which produce an ultra-high purity oxygen product and nitrogen and/or commercial purity oxygen products. In particular, the improvement of the present invention is characterized by removing a portion of liquid descending the distillation column system from the distillation section proximate to the location for withdrawing the oxygen-containing side-draw stream.
    Type: Grant
    Filed: August 29, 1995
    Date of Patent: January 7, 1997
    Assignee: Air Products and Chemicals, Inc.
    Inventors: Rakesh Agrawal, Donn M. Herron, Thomas R. White