Patents Represented by Attorney, Agent or Law Firm Robert J. Follett
  • Patent number: 6648946
    Abstract: This invention is directed to a process for recovering helium. The process includes a) passing a first gas containing helium to an eductor to produce a second gas; b) passing the second gas through a heat exchanger to produce a third gas; and c) recovering the third gas into the eductor to combine with the first gas.
    Type: Grant
    Filed: May 31, 2001
    Date of Patent: November 18, 2003
    Assignee: Praxair Technology, Inc.
    Inventor: James Joseph Volk
  • Patent number: 6632767
    Abstract: The low stability of some molecular sieves can be overcome during calcination by a solid state reaction between the molecular sieve and a salt. Molecular sieves including zeolites, metal substituted aluminosilicates, and metallosilicates can be stabilized by this method. The inventive process comprises mixing such molecular sieve with a salt, either directly or as a slurry; and then heating the resulting mixture to remove water, organics and adsorbed species.
    Type: Grant
    Filed: December 19, 2000
    Date of Patent: October 14, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Qisheng Huo, Neil Andrew Stephenson
  • Patent number: 6622496
    Abstract: This invention is directed to an external loop nonfreezing heat exchanger for cooling a heat transfer fluid with cryogenic fluid. The cryogenic fluid is first pre-vaporized with the spent cryogenic fluid. The heat transfer fluid is then cooled by the vaporized cryogenic fluid instead of the cryogenic fluid feed directly.
    Type: Grant
    Filed: July 12, 2001
    Date of Patent: September 23, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Donald Leonard DeVack
  • Patent number: 6613949
    Abstract: This invention is directed towards an improved process for the selective gas phase oxidation of a organic reactant using a metal oxide redox catalyst, wherein the organic reactant and air feeds are at a substantially continuous level, the improvement comprising adding a fluctuating flow of oxygen at alternating relatively high and relatively low levels. The invention also teaches means by which a gas may be provided to a reaction process on a fluctuating basis.
    Type: Grant
    Filed: March 10, 1997
    Date of Patent: September 2, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Matthew Lincoln Wagner, Donald Walter Welsh Kirkwood, Kazuo Kiyonaga
  • Patent number: 6581412
    Abstract: This invention is directed to a method for delivering a liquefied compressed gas with a high rate of flow comprising passing a liquefied compressed high-purity semiconductor gas into a storage vessel; positioning a temperature measuring means onto the wall of the compressed gas storage vessel; positioning at least one heating means proximate to the storage vessel; monitoring the resulting temperature with the temperature measuring means; positioning a pressure measuring means at the outlet of the storage vessel and monitoring the vessel pressure; adjusting the heat output of the heating means to heat the liquefied compressed gas in the storage vessel to control the evaporation of the liquefied compressed gas in the storage vessel; and controlling the flow of the gas from the storage vessel.
    Type: Grant
    Filed: August 13, 2002
    Date of Patent: June 24, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Atul Pant, Melvyn Richardson, Mike Leshner
  • Patent number: 6570127
    Abstract: The shielding gas mixture is useful for MIG brazing galvanized steel. The gas mixture having by volume percent, about 0.5 to 4 carbon dioxide, about 0.2 to 1 hydrogen, and the balance is argon and incidental impurities.
    Type: Grant
    Filed: May 3, 2001
    Date of Patent: May 27, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: João Vinicíus de Oliveira Correia, Jeferson Frederico Monteiro Costa
  • Patent number: 6551384
    Abstract: An advanced medical concentrator process and system is provided using fast cycle and advanced adsorbent. Significant improvements achieved results in a smaller, lighter and more efficient system in comparison with the current commercial stationary concentrators. Integrated with a conserver, a small portable concentrator is achieved.
    Type: Grant
    Filed: July 5, 2001
    Date of Patent: April 22, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Mark William Ackley, Guoming Zhong
  • Patent number: 6551573
    Abstract: A low silica AFI zeolite and a high purity gmelinite zeolite that have a SiO2/Al2O3 ratio of about 10 or less are provided.
    Type: Grant
    Filed: March 27, 2002
    Date of Patent: April 22, 2003
    Assignee: Praxair Technology, Inc.
    Inventor: Qisheng Huo
  • Patent number: 6547859
    Abstract: A process for making microporous membranes that incorporate selected gas selective species as surface sites in a controlled spacing and orientation manner and such membranes so formed being suitable for separating and purifying the selected gas from selected gas containing gas mixtures. An example is the use of oxygen selective transition element complexes (TECs) as surface sites for separating and purifying oxygen from oxygen-containing gas mixtures.
    Type: Grant
    Filed: November 21, 2000
    Date of Patent: April 15, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Joseph Timothy Mullhaupt, Neil Andrew Stephenson, Frank Notaro, Ravi Prasad
  • Patent number: 6527830
    Abstract: A pressure swing adsorption process for recovery of a more readily adsorbable component, such as nitrogen, and a larger amount of a less readily adsorbable component, such as oxygen, from a feed gas mixture, such as air, wherein the ratio of nitrogen to oxygen is less than about 3:1 and the ratio of the co-purge:feed gas of the process is maintained at less than about 1.15:1.
    Type: Grant
    Filed: October 3, 2001
    Date of Patent: March 4, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Bernard T. Neu, James Smolarek, Andrew C. Rosinski, Mark William Ackley
  • Patent number: 6527831
    Abstract: A pressure swing process and system for purifying a first gas, preferably argon, from a crude feed gas stream containing the first gas and second gas(es) utilizes two adsorption beds and continuously promotes the crude feed gas to the bed during the process and simultaneous equalization of pressure in the two beds in top-to-top end and bottom-to-bottom end equalizations in each bed following purging of each bed.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: March 4, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Mohamed Safdar Allie Baksh, Alan Barnard Stewart
  • Patent number: 6521772
    Abstract: This invention is directed to a method for producing an alkyl-substituted metallocene complex comprising the steps of mixing a metallocene with a solvent to form a metallocene-solvent mixture; mixing the metallocene-solvent mixture with an effective amount of a metallation reagent to produce a metallated-metallocene; and mixing said metallated-metallocene with an electrophilic alkyl-reagent to form an alkyl-substituted metallocene complex.
    Type: Grant
    Filed: September 27, 2001
    Date of Patent: February 18, 2003
    Assignees: Praxair Technology, Inc., Research Foundation of Suny
    Inventors: Michael Alexander Lienhard, Cynthia A. Hoover, Jim D Atwood, David C. Hoth
  • Patent number: 6506234
    Abstract: A gas separation process incorporating the invention combines use of an adsorbent having high intrinsic diffusivity with a low pressure ratio PSA cycle. Further enhancements to the process are derived from the use of fast cycles, shallow beds and small particles—especially in a radial bed configuration. The combination of low pressure ratio, high rate adsorbents and fast cycles has been found to result in an unexpected simultaneous reduction in bed size factor (BSF) and power consumption. These benefits have been achieved while minimizing a decline in product recovery through use of the high rate adsorbent. The net result is a significant reduction in product cost.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: January 14, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Mark William Ackley, James Smolarek, Frederick Wells Leavitt
  • Patent number: 6503299
    Abstract: This invention provides a two bed pressure swing adsorption process for recovering a primary gaseous component at a purity of over 99% from a feed gas comprising the primary component and one or more impurities.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: January 7, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Mohamed Safdar Allie Baksh, Charles Edward Terbot
  • Patent number: 6500235
    Abstract: An improved pressure swing adsorption process and system for producing a high recovery of a highly purified product gas, such as argon, from a feed gas stream containing the product gas and impurity gases employs first and second adsorption stages with beds for adsorbing impurity gases. The system and process provides for sequential steps of: feed pressurization; simultaneous feed pressurization and product pressurization; adsorption; adsorption and purge; adsorption in the absence of purge; pressure equalization between beds; evacuation and depressurization of adsorbent bed; evacuation with product purge; evacuation without purge; and pressure equalization between beds.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: December 31, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Guoming Zhong, Mohamed Safdar Allie Baksh, Frank Notaro, Frederick Wells Leavitt
  • Patent number: 6500234
    Abstract: The invention is based upon the recognition that intrinsic sorption rates of adsorbent materials have a significant impact upon process performance. In a preferred embodiment an adsorption process uses an adsorbent zone comprising an adsorbent selected from the group consisting of A-zeolite, Y-zeolite, NaX, mixed cation X-zeolite, LiX having a SiO2/Al2O3silica/alumina ratio of less than 3.0, chabazite, mordenite, clinoptilolite, silica-alumina, alumina, silica, titanium silicates and mixtures thereof, wherein the adsorbent has a mass transfer coefficient for nitrogen of kN2≧12 s−1 and an intrinsic diffusivity for N2, when measured at 1.5 bar and 300K, of Dp≧3.5×10−6 m2/s. Other embodiments include the development of process parameters around which such materials should be used and methods of making such materials.
    Type: Grant
    Filed: October 10, 2000
    Date of Patent: December 31, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Mark William Ackley, Frederick Wells Leavitt
  • Patent number: 6497747
    Abstract: A process for preparing polyimide gas separation membranes is disclosed. The process involves preparing polyamic acid salt membrane precursors that are converted into polyimide membranes by mild thermal or chemical treatments. The gas separation processes that utilize these polyimide membranes are further disclosed.
    Type: Grant
    Filed: September 24, 1999
    Date of Patent: December 24, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Yong Ding, Benjamin Bikson, Joyce Katz Nelson
  • Patent number: 6475265
    Abstract: The present invention is a two stage PSA process for producing high purity oxygen from a feed air stream. Water, carbon dioxide and nitrogen are removed in a first stage. An oxygen selective adsorbent is used to adsorb oxygen in the second stage. High purity oxygen product is recovered during regeneration of the second stage. Importantly, the high purity of the oxygen product is achieved without inclusion of an oxygen rinse step in the process cycle. The high purity oxygen product is obtained by collecting the middle cut of the second stage effluent stream during regeneration.
    Type: Grant
    Filed: October 22, 1998
    Date of Patent: November 5, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Mohamed Safdar Allie Baksh, Atanas Serbezov, Frank Notaro, Frederick Wells Leavitt
  • Patent number: 6471748
    Abstract: The invention comprises a PSA process and apparatus wherein the fixed adsorbent bed comprises an equilibrium zone and a mass transfer zone. Further, the equilibrium and mass transfer zones each comprise at least one adsorbent material, selective for the adsorption of a more selectively adsorbable component, that is selected on the basis of the performance of that adsorbent material under the process conditions applicable to the zone.
    Type: Grant
    Filed: November 9, 2000
    Date of Patent: October 29, 2002
    Assignee: Praxair Technology, Inc.
    Inventor: Mark William Ackley
  • Patent number: 6471937
    Abstract: The invention comprises a reactor having a source of a first hot reactant gas, a mixing chamber in which said first hot reactant gas mixes with a second reactant gas to form a reactant gas mixture, but wherein substantially no reaction takes place and a reaction zone wherein said mixture undergoes vapor phase reaction. A process for using the reactor is also disclosed.
    Type: Grant
    Filed: September 4, 1998
    Date of Patent: October 29, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: John Erling Anderson, Arthur Wellington Francis, Jr., Matthew Lincoln Wagner, Christopher Brian Leger