Patents Represented by Attorney, Agent or Law Firm Donald T. Black
  • Patent number: 6464827
    Abstract: A method for producing pulp, comprising digesting lignocellulosic wood, containing one or more xylan derivatives selected from the group consisting of xylan bound with lignin, xylan bound with hexenuronic acid, and mixtures thereof, with an aqueous alkaline pulping solution containing sulfide and having an initial free hydroxyl ion concentration of at least 1 mole per liter, under conditions whereunder xylan is dissociated from said one or more xylan derivatives and the pH of the solution remains above 12.5; and then while the pH of said solution is above 12.5, adding a sufficient amount of an acidic agent to said pulping solution to precipitate dissociated xylan from said pulping solution while minimizing precipitation of lignin from said pulping solution. Carbon dioxide is a preferred acidic agent.
    Type: Grant
    Filed: November 28, 2000
    Date of Patent: October 15, 2002
    Assignee: Praxair Technology, Inc.
    Inventor: Jorge Luiz Colodette
  • Patent number: 6455102
    Abstract: Silica-based refractories are impregnated with protective material that is more resistant towards attack by corrosive species. The protective material coats the surface of the refractory matrix and fills some of the cavity volume of its pores, crevices, surfaces imperfections and irregularities. The protective material is positioned by impregnating the refractory with a precursor which, under the input of energy, is converted into the corrosion resistant protective material.
    Type: Grant
    Filed: September 20, 2000
    Date of Patent: September 24, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: William Thoru Kobayashi, Elson Longo Da Silva, Carlos Alberto Paskocimas
  • Patent number: 6394790
    Abstract: A combustion method for carrying out combustion with reduced generation of NOx wherein high velocity fuel and oxidant in a very low substoichiometric ratio are combusted and thereafter secondary oxidant mixes and combusts with the resulting combustion reaction products.
    Type: Grant
    Filed: May 13, 1996
    Date of Patent: May 28, 2002
    Assignee: Praxair Technology, Inc.
    Inventor: Hisashi Kobayashi
  • Patent number: 6382763
    Abstract: The tendency of gas-propelled ink jet printing systems to clog, and to consume increased amounts of vehicle, is relieved in systems wherein the ink contains one or more components which increase in particle size upon contact with water, by employing gas and vehicle which either contain no water or together contain less water than would be sufficient to cause said increase in particle size.
    Type: Grant
    Filed: January 24, 2000
    Date of Patent: May 7, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Alexandre Albuquerque, Elcio Bien, Marcelo Santos
  • Patent number: 6368413
    Abstract: Disclosed is a process for preparing an improved sugar product comprising (a) providing a raw sugar solution having color of 50 to 1,000 Icumsa units and a concentration of 10 to 70 Brix; (b)(1) injecting ozone into the raw sugar solution while imparting agitation to the solution effective to reduce the size of said color-imparting particles into smaller particles, and then (b)(2) discontinuing said injection, but continuing said agitation for a period of time in excess of the duration of step (b)(1), wherein said smaller particles react with ozone, and (c) optionally repeating steps (b)(1) and (b)(2) at least once, wherein the solution is at no point subjected to a precipitation or carbonation step.
    Type: Grant
    Filed: July 26, 2000
    Date of Patent: April 9, 2002
    Assignees: Praxair Technology, Inc., Dulcini S/A
    Inventors: Philippe Georges Charlet, Jorge Luiz Colodette, Carlos Roberto Xavier, Julio Cesar Mascioli
  • Patent number: 6369192
    Abstract: The present invention relates to a method for treating plastic polymers to reduce or remove organic contaminants. More particularly, the present invention relates to a method of treating, by continuous means, a flowable polymer mass with a solvating fluid in an environment at which the solvating fluid is in a supercritical state and is subject to conditions sufficient to preferentially solvate and extract organic, and especially non-volatile, contaminants from the polymer mass.
    Type: Grant
    Filed: October 25, 1996
    Date of Patent: April 9, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Louise Anne Dufresne, Rajat Darshan Agrawal
  • Patent number: 6355292
    Abstract: The tendency of carbonated beverage to generate excessive foam when it is produced and bottled is reduced in a process including: (a) providing water or a mixture of water and syrup, which contains oxygen or air dissolved therein, and maintaining a pressure greater than atmospheric thereon; (b) saturating said mixture with carbon dioxide, and feeding the resultant mixture to step (c), while maintaining sufficient pressure thereon that no dissolved gas evolves therefrom; and (c) removing dissolved oxygen or air from the mixture formed in step (b) while dissolving additional carbon dioxide into said mixture and maintaining over said mixture a pressure greater than atmospheric.
    Type: Grant
    Filed: January 27, 2000
    Date of Patent: March 12, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Alan T. Cheng, Pedro L. Durao
  • Patent number: 6348129
    Abstract: An aqueous stream such as pulp mill condensate containing one or more sulfur compounds is treated by (a) reacting an aqueous feed stream containing TRS contaminant selected from the group consisting of hydrogen sulfide, methyl mercaptan, dimethyl sulfide, dimethyl disulfide, and mixtures thereof, with ozone to produce a first liquid product stream and a first gaseous product stream, wherein the total amount of said one or more contaminants in said first liquid product stream is less than 1% of the amount thereof in said feed stream, and wherein said first gaseous product stream contains ozone and one or more of said contaminants; and (b) treating said first gaseous product stream with an alkaline aqueous stream to remove essentially all of said one or more contaminants from said first gaseous product stream. Preferably, a second gaseous stream produced in step (b) and containing ozone is reacted with an aqueous stream containing one or more of said contaminants, to consume all the ozone in said stream.
    Type: Grant
    Filed: April 28, 2000
    Date of Patent: February 19, 2002
    Inventors: Jorge Luiz Colodette, Philippe Charlet
  • Patent number: 6334330
    Abstract: A cooling tunnel system that includes a conveyor for carrying objects through a tunnel chamber. The conveyor enables a cooling fluid to pass therethrouqh and about the objects. A plurality of slot means feeds the cooling fluid to the conveyor means. Each slot means includes at least one aperture for enabling vapor flow onto and about the objects. A plenum adjacent the plurality of slot means distributes the cooling fluid. And at least one fan in the tunnel chamber causes a flow of the cooling fluid into the plenum and through the slot means with sufficient velocity to impinge upon and cool the objects and to recirculate the cooling fluid within the tunnel chamber.
    Type: Grant
    Filed: January 22, 2001
    Date of Patent: January 1, 2002
    Assignee: Praxair, Inc.
    Inventors: Gary Dee Lang, Theodore Hall Gasteyer, III, Yeu-Chaun Simon Ho
  • Patent number: 6335074
    Abstract: A thermal insulation panel exhibits little or no warping due to temperature differences between different portions of the panel. The panel comprises insulation material and an envelope for encapsulating the insulation material. The envelope comprises a base member and a cover member. The cover member is supported by the base member in a floating and sealing engagement with the base member. The cover member can slide relative to the base member to compensate for differential thermal expansion effects on the respective base member and cover member. In an alternative embodiment the cover member is adapted to be exposed to a temperature significantly below the temperature to which the base member is exposed. The cover member is formed of a metal having a low coefficient of thermal expansion to compensate for differential thermal expansion effects in the respective base member and cover member. The cover member and the base member are joined to provide the envelope with a hermetic seal.
    Type: Grant
    Filed: February 29, 2000
    Date of Patent: January 1, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Theodore Hall Gasteyer, III, Gary Dee Lang
  • Patent number: 6274102
    Abstract: A small system for efficiently producing low flow rates of a nitrogen or nitrogen/hydrogen stream from an initial feed which also contains oxygen, employing a defined catalytic reactor unit producing product at very high space velocities.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: August 14, 2001
    Assignee: Praxair Technology, Inc.
    Inventor: Jaak Stefaan Van den Sype
  • Patent number: 6253578
    Abstract: A glassmelting apparatus which reduces alkali corrosion comprising: a glassmelting furnace having a plurality of walls, a crown, a charge end, a batch melting area and a fining area; at least two low momentum oxy-fuel burners located in at least one of the walls of the glassmelting furnace, each burner having at least one gas exit port, the lowest point of each gas exit port of each burner having a vertical position that is raised to a height of about 18 inches to about 36 inches above the surface of the glass; each oxy-fuel burner generating a flame along a path directed towards an opposite vertical wall of the glassmelting furnace; and said interior intersection of said walls and said crown of said glassmelting furnace being located at a height of between about 5.5 feet and 9 feet above the glassmelt surface.
    Type: Grant
    Filed: April 12, 1996
    Date of Patent: July 3, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Hisashi Kobayashi, Kuang-Tsai Wu
  • Patent number: 6245196
    Abstract: The process of the present invention purposefully precipitates a portion of the dissolved lignin onto pulp fibers to improve pulp yield of unbleached pulp. The resulting retention of lignin on the pulp creates an increase in pulp yield. Washing the pulp in a series of washer stages sequentially removes entrained lignin. Between each of the washer stages, adding dilution water repulps a pulp mat that exits from a prior washer stage and creates a pulp stream for a next washer stage. After at least one of the washer stages, adding an acidifying agent to the pulp stream forms a pulp product by precipitating the entrained lignin onto cellulosic fibers contained in the pulp stream. Finally, the process removes the pulp product from the series of washer stages with the pulp product having at least about a 1 unit increase in Kappa number.
    Type: Grant
    Filed: February 2, 1999
    Date of Patent: June 12, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Pierre Henri Rene Martin, Jacobo Kogan, Ka Kee Ho, Peter Campbell
  • Patent number: 6210157
    Abstract: A regenerative furnace without flue gas circulation to the regenerator beds is heated by combusting synthesis gas with an oxidant. The synthesis gas is produced from steam and methane in a first regenerator bed, heated in the previous cycle while a second regenerator bed, cooled in the previous cycle, is heated by passing through it a hot flue gas from a source other than the furnace. Once the first regenerator bed is cooled through the endothermic chemical reaction of the steam and methane, it is heated by hot flue gas, while steam and methane are reacted in the second, now hot, bed thereby cooling it.
    Type: Grant
    Filed: April 7, 2000
    Date of Patent: April 3, 2001
    Assignee: Praxair Technology, Inc.
    Inventor: Hisashi Kobayashi
  • Patent number: 6205813
    Abstract: A natural gas purification system which can produce both fuel and high purity hydrocarbon product such as high purity methane or high purity natural gas wherein high temperature carbon dioxide removal is followed by cryogenic rectification to produce fuel and high purity hydrocarbon product.
    Type: Grant
    Filed: July 1, 1999
    Date of Patent: March 27, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Minish Mahendra Shah, James Joseph Maloney, Raymond Francis Drnevich
  • Patent number: 6200631
    Abstract: Silica-based refractories are impregnated with protective material that is more resistant towards attack by corrosive species. The protective material coats the surface of the refractory matrix and fills some of the cavity volume of its pores, crevices, surfaces imperfections and irregularities. The protective material is positioned by impregnating the refractory with a precursor which, under the input of energy, is converted into the corrosion resistant protective material.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: March 13, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: William Thoru Kobayashi, Elson Longo Da Silva, Carlos Alberto Paskocimas
  • Patent number: 6200416
    Abstract: A method for the manufacture of paper products includes the feeding of a carbon dioxide stream to a product flow which includes a material containing an aluminum compound. The material is preferably wastepaper containing aluminum sulfate or papermaker's alum. The material may also be a product flow of wastepaper (containing aluminum sulfate) to which a supply of virgin pulp has been added. The carbon dioxide addition to the product flow reduces the pH of the product flow to a level of acidity which allows a dissolution of the aluminum compound and incorporation thereof throughout the product flow.
    Type: Grant
    Filed: June 10, 1997
    Date of Patent: March 13, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Jefferson Luis Brotto, Douglas Barbosa Madeiros, Alexandre Sayao Valladares, John Allen Slocumb
  • Patent number: 6200128
    Abstract: A method and apparatus for recovering sensible heat from a hot exhaust gas having an oxygen concentration of less than 21 vol % in a fuel-air fired combustion device. An oxidant stream comprising a gas having an oxygen concentration of greater than 21 vol % is introduced into the combustion process to form an oxidant mixture comprising the hot exhaust gas, the oxidant and any air present, the mixture having an average combined oxygen concentration of less than 21 vol %.
    Type: Grant
    Filed: June 9, 1997
    Date of Patent: March 13, 2001
    Assignee: Praxair Technology, Inc.
    Inventor: Hisashi Kobayashi
  • Patent number: 6192706
    Abstract: A system for producing carbon monoxide wherein a carbon monoxide containing feed stream is processed in a membrane separation unit for partial removal of carbon dioxide, cooled to complete the removal of carbon dioxide, and then processed in a cryogenic separation system comprising a first cryogenic separation column and a second cryogenic separation column for the production of product carbon monoxide.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: February 27, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Thomas John Bergman, Jr., John Fredric Billingham, Michael Robert Couche, Minish Mahendra Shah
  • Patent number: 6190632
    Abstract: A system for producing ammonia by integrating blast furnace ironmaking with ammonia production wherein cryogenic rectification links the two systems enabling the production of ammonia synthesis gas from blast furnace gas for use in the ammonia production.
    Type: Grant
    Filed: February 25, 1999
    Date of Patent: February 20, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Minish Mahendra Shah, Raymond Francis Drnevich