Abstract: This invention is directed to a method for annealing strand wires or strips in a fluidized bed reactor having an atmosphere of fluidized gases flowing through fluidized particles. The method provides for stratifying the atmosphere of fluidized gases by passing a reducing gas through the fluidized particles in the fluidized bed. The wires are passed between the fluidized particles at a location near the bottom of the fluidized bed. Finally, an amount of oxygen-containing gas is injected on top of said fluidized bed reactor.
Abstract: This invention is directed to a method and system for using laminar barrier inerting techniques to shroud a selected area in an open space covering the polymeric film outlet and/or raw material inlet with inert gas.
Type:
Grant
Filed:
February 16, 1999
Date of Patent:
August 7, 2001
Assignee:
Praxair Technology, Inc.
Inventors:
Robert Marcel De Wilde, Pascal Yves Duro
Abstract: This invention is directed to a method, and a system therefor, for recovering PFC using condensation by passing a PFC-containing feed stream into a condenser, preferably reflux condenser, to effect liquefaction into a PFC-containing condensate and a carrier gas stream, and passing the PFC-containing product into a mass transfer unit to fractionate the PFC-containing condensate into a high volatility PFC stream and a PFC product.
Type:
Grant
Filed:
June 28, 1999
Date of Patent:
July 10, 2001
Assignee:
Praxair Technology, Inc.
Inventors:
Richard Martin Kelly, Dante Patrick Bonaquist
Abstract: This invention is directed to a method of making supersaturated oxygenated liquid by introducing a high oxygen content gas to an ozone generator to produce ozone, passing the ozone to a contact tank at atmospheric pressure to produce an oxygenated and ozonated liquid, and passing the oxygenated and ozonated liquid in a contacting loop of an in-line supersonic mixer to produce a substantially pure supersaturated oxygenated and ozonated liquid.
Type:
Grant
Filed:
June 30, 1999
Date of Patent:
June 26, 2001
Assignee:
Praxair Technology, Inc.
Inventors:
Alan Tat Yan Cheng, Timothy Michael Lewis, Russell Steve Plancich
Abstract: The invention is a method of removing materials such as carbon and metallic elements from a substrate surface via heating in an atmosphere of molecular chlorine and steam. In a preferred embodiment, carbon residue is removed from the surface of a Si or GaAs substrate material.
Type:
Grant
Filed:
November 5, 1999
Date of Patent:
June 5, 2001
Assignee:
Praxair Technology, Inc.
Inventors:
Arthur Edward Holmer, Michael Mark Litwin, Kevin Bruce Albaugh
Abstract: A method and apparatus for controlling the temperature of a freeze drying chamber shelves and chamber in a refrigeration system having a condenser operatively associated therewith using the circulation of a cryogen through the condenser and of a cryogenically cooled heat transfer fluid through the chamber shelves for controlling the temperature therein, and also where the temperature of the cryogenically cooled heat transfer fluid having been regulated by an exchange of heat with the cryogen.
Type:
Grant
Filed:
September 21, 1998
Date of Patent:
April 24, 2001
Assignee:
Praxair Technology, Inc.
Inventors:
Donald Stuart Finan, Sr., Alan Tat Yan Cheng
Abstract: The amount of a ballast gas needed, to prevent combustion, deflagration, and/or detonations during a liquid phase reaction of molecular oxygen and a flammable process liquid, is reduced by using a ballast gas other than nitrogen. The ballast gas is selected to have a boiling point lower than the boiling point of the flammable process liquid and selected to produce a higher limiting oxygen value (LOV) in a mixture with the flammable process liquid vapor and molecular oxygen than the LOV for the corresponding mixture substituting just nitrogen for the inerting gas.
Type:
Grant
Filed:
October 20, 1998
Date of Patent:
April 10, 2001
Assignee:
Praxair Technology, Inc.
Inventors:
Vasilis Papavassiliou, William Robert Williams, Matthew Lincoln Wagner
Abstract: A process is described for producing nitric acid involving oxidizing ammonia gas to form dinitrogen tetroxide gas, reacting the dinitrogen tetroxide with water in an absorption zone to form aqueous nitric acid and nitric oxide gas, removing a nitric acid/nitric oxide stream from the absorption zone and feeding the stream into a nitric acid bleaching zone, removing impurities from the nitric acid in the bleaching zone to form nitric acid product and adding supplemental oxygen gas to one or more of the reaction streams to increase nitric acid production and or strength. The improvement involves injecting the supplemental oxygen into a nitric acid-containing process stream to form a gas bubble/liquid mixture in the stream, the mixture forming a fine dispersion of gas bubbles having diameters of less than about 0.1 mm.
Type:
Grant
Filed:
December 24, 1998
Date of Patent:
December 26, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
Diego Fernandez Echegaray, Antonio Augusto M. Velloso, Matthew Lincoln Wagner
Abstract: A system provides an oxygen-bearing gas and a gaseous reactant stream to a fluidized bed reactor. A sparger causes an entraining of the oxygen bearing gas into the reactant gas stream. A feed line couples the sparger to the reactor's fluidized bed and introduces the reactant gas stream and entrained oxygen-bearing gas directly into contact with the fluidized bed. A controller controls both the amount of oxygen-bearing gas and the gaseous reactant so that, at the point of feed injection, the fluidized bed catalyst does not experience an oxygen deficiency. To assure safety, the reactant content of the combined feed and oxygen stream is maintained above an upper flammability limit, preferably with a safety margin of at least 25%. In one embodiment, the system enables the production of acrylonitriles from a feed stream comprising ammonia, propylene and oxygen.
Type:
Grant
Filed:
March 9, 1998
Date of Patent:
December 5, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
Matthew Lincoln Wagner, Thomas John Bergman, Jr.
Abstract: A combustion or partial oxidation process for using an oxidant with a low nitrogen concentration. An oxygen-containing gas is introduced into an ion transport module including an ion transport membrane having a retentate side with a first pressure and a permeate side with a second pressure to separate a purified oxygen gas stream on the permeate side and correspondingly depleting the oxygen on the retentate side to produce the oxygen-depleted gas stream. A purge gas stream containing a low concentration of nitrogen is passed to the permeate side to form an oxidant stream containing less than about 40% oxygen. The oxidant stream and a fuel are then introduced into a combustion or reaction chamber to produce heat and products of combustion or partial oxidation.
Abstract: A system for the dissolution of gas in a large body of liquid comprising an impeller positioned below the surface of the large body of liquid; a floating hood positioned over the impeller and of sufficient size to capture undissolved gas; a conduit for introducing a feed gas stream beneath the floating hood and directly into the large body of liquid; at least one segregation ring positioned under the floating hood and extending below the surface of the large body of liquid such that a first inner region between the ring and the impeller, and a second outer region between the ring and an outer diameter of the floating hood are created, and a back pressure regulator located in the floating hood adjacent to the outer diameter of the floating hood.
Type:
Grant
Filed:
December 2, 1998
Date of Patent:
November 14, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
Alan Tat Yan Cheng, Steven Donald Clark, Paolo Sergio Bon, Thomas John Bergman, Jr., Jeffrey Paul Kingsley, Mark Herbert Kirby, Mitchell Adis, Victor Alexander Coppola
Abstract: Oxygen or other gases are dissolved in large bodies of liquid by injection under a baffle for passage into a submerged hollow draft-tube-impeller means assembly for downward passage therein. Liquid containing dissolved gas is dispersed throughout the body of liquid, while any undissolved gas is effectively recovered and recycled.
Type:
Grant
Filed:
April 24, 1998
Date of Patent:
October 24, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
Thomas John Bergman, Jr., Jeffery Paul Kingsley, Mark Herbert Kirby, Mitchell Adis, Victor Alexander Coppola
Abstract: This invention is directed to a method for producing UHP tungsten hexafluoride by introducing an amount of crude tungsten hexafluoride to an evaporating process for separation into an amount of tungsten hexafluoride-containing volatile impurities and an amount of non-volatile metallic impurities; passing the amount of tungsten hexafluoride-containing volatile residue to a gas phase adsorption process for separation into an amount of semi-crude tungsten hexafluoride product and an amount of hydrogen fluoride non-volatile residue; and passing the amount of semi-crude tungsten hexafluoride product to a sparging system using UHP helium for separation into a non-volatile UHP tungsten hexafluoride product.
Abstract: A shell and tube heat exchanger reactor with forced circulation is used to improve heat and mass transfer for exothermic liquid--liquid, gas-liquid and gas-liquid-solid reactions. Enhanced productivity and selectivity are obtained.
Type:
Grant
Filed:
July 23, 1998
Date of Patent:
July 4, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
Jeffrey Paul Kingsley, Mitchell Adis, Friedrich E. Purkert
Abstract: A process for producing synthesis gas and hydrogen by passing a compressed and heated oxygen-containing gas mixture into a reactor having at least one solid electrolyte oxygen ion transport membrane to separate transported oxygen Organic fuel reacts with the oxygen to form synthesis gas. The resulting synthesis gas is separated into hydrogen gas through at least one solid electrolyte hydrogen transport membrane to separate the transported hydrogen in the same or different separator.
Type:
Grant
Filed:
September 15, 1999
Date of Patent:
May 23, 2000
Inventors:
Nitin Ramesh Keskar, Ravi Prasad, Christian Friedrich Gottzmann
Abstract: A process for the generation of a protective nitrogen-based atmosphere for the performance of heat treatments of metal articles in three phases, including an initial phase in which a gaseous hydrocarbon feed and an oxidant containing oxygen react on a first catalyst to form a reaction product, a second phase in which the reaction product is added to nitrogen contaminated by the presence of oxygen and a third phase in which the reaction product is conveyed to a second catalyst to form a low-dew point gaseous mixture as a protective atmosphere.
Type:
Grant
Filed:
March 11, 1998
Date of Patent:
April 18, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
Jaak Stefaan Vandensype, Gianluca Porto
Abstract: This invention is directed to a method for producing ethylene oxide comprising feeding ethylene, high purity oxygen and a ballast gas with a recycle gas in a catalyst filled reactor to form a gaseous mixture; passing the gaseous mixture from the reactor to a recovery unit to selectively separate ethylene oxide and carbon dioxide containing gas; passing at least a portion of the carbon dioxide containing gas to a stripping unit to selectively separate carbon dioxide and a waste gas; passing at least a portion of the waste gas to purge and another portion for recycling as the recycle gas; and recovering ethylene oxide from the recovery unit.
Type:
Grant
Filed:
July 24, 1997
Date of Patent:
March 21, 2000
Assignee:
Praxair Technology, Inc.
Inventors:
Vasilis Papavassiliou, Matthew Lincoln Wagner, Roger William Day
Abstract: A method for producing vinyl acetate using ethylene, acetic acid and argon containing oxygen that maximizes selectivity and minimizes ethylene loses to purge.
Type:
Grant
Filed:
December 31, 1997
Date of Patent:
September 14, 1999
Assignee:
Praxair Technology, Inc.
Inventors:
Vasilis Papavassiliou, Matthew Lincoln Wagner, Roger William Day
Abstract: A solid electrolyte ion transport membrane composite for separating a gaseous species from a gaseous mixture in which the composite has a dense matrix material and a porous coating. The dense membrane is comprised of a matrix material which conducts at least one type of ion, and at least one membrane constituent. The porous coating is disposed on the membrane to enhance the rate of surface reactions involving the gaseous species.
Type:
Grant
Filed:
May 2, 1997
Date of Patent:
August 17, 1999
Assignee:
Praxair Technology, Inc.
Inventors:
Chieh Cheng Chen, Ravi Prasad, Christian Friedrich Gottzmann
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.