Patents Represented by Attorney Chung K. Pak
  • Patent number: 5601425
    Abstract: A combustion method is provided for carrying out combustion with reduced generation of nitrogen oxides. The combustion method involves partially combusting a fluid fuel stream with a low velocity oxidant and thereafter mixing and combusting the resulting product with a secondary oxidant stream diluted with ambient gas. The velocity of the secondary oxidant stream is either increased to reduce the nitrogen oxides emission level or adjusted to provide the desired secondary oxidant/low velocity oxidant ratio which is useful for further decreasing the formation of nitrogen oxides. Normally, increasing the ratio and/or velocity further decreases the nitrogen oxides emission level. When liquid fuel is employed, it is atomized with atomizing fluid in such a manner to produce a liquid fuel stream having a very narrow spray angle. The production of such a stream allows the burner to be operated without water cooling.
    Type: Grant
    Filed: June 13, 1994
    Date of Patent: February 11, 1997
    Assignee: Praxair Technology, Inc.
    Inventors: William T. Kobayashi, Arthur W. Francis, Jr., Hisashi Kobayashi
  • Patent number: 5486383
    Abstract: A process and system for shielding a turbulent fluid stream, comprising emitting a laminar flow of a shielding gas transversely to the flow direction of the turbulent fluid stream preferably from a porous wall. The turbulent fluid stream may be hot and may contain a coating material. By projecting or directing the turbulent fluid stream at the surface of a substrate to be coated, the heated coating material is deposited on the surface of the substrate.
    Type: Grant
    Filed: August 8, 1994
    Date of Patent: January 23, 1996
    Assignee: Praxair Technology, Inc.
    Inventors: Mark S. Nowotarski, Don J. Lemen, William J. Snyder, David B. Leturno
  • Patent number: 5459994
    Abstract: A system and method of operating a system comprising an air separation plant and a gas turbine engine, the method comprising: providing a nitrogen-rich stream from the air separation plant; expanding and thereby cooling the nitrogen-rich stream; and delivering the expanded stream to the inlet of the compressor of the gas turbine engine to combine with the air stream entering the inlet of the compressor to form a total feed stream with reduced temperature and oxygen content so as to increase power output, increase efficiency and reduce NOx emissions of the gas turbine.
    Type: Grant
    Filed: May 28, 1993
    Date of Patent: October 24, 1995
    Assignee: Praxair Technology, Inc.
    Inventor: Raymond F. Drnevich
  • Patent number: 5460003
    Abstract: A turboexpander, particularly suited for use in a cryogenic rectification system, comprises a center housing rotatably supporting an elongated shaft to opposite ends of which are mounted a turbine wheel within a turbine housing and a compressor wheel within a compressor housing or a brake within a load housing. The turbine wheel has circumferentially spaced turbine blades. Process fluid is introduced so as to flow through annular nozzles or guide vanes which encompass the turbine wheel. The guide vanes direct the process fluid through the turbine blades and each extends between a leading edge more distant from the turbine wheel and a trailing edge less distant from the turbine wheel. Each guide vane is substantially uncontoured between its leading edge and the trailing edge and is substantially thicker at the leading edge than at the trailing edge.
    Type: Grant
    Filed: June 14, 1994
    Date of Patent: October 24, 1995
    Assignee: Praxair Technology, Inc.
    Inventor: Neno T. Nenov
  • Patent number: 5458672
    Abstract: A Process for combusting sulfur vapor released from a sulfur bearing material, comprising:(a) introducing a sulfur bearing material into a furnace having a combustion zone;(b) ejecting at least one fuel stream with or without a substoichiometric amount of at least one primary oxidant stream and combusting said at least one fuel stream with the substoichiometric amount of the primary oxidant stream or ambient gas in the combustion zone to produce heat sufficient to release some sulfur vapor from the sulfur bearing material and to form combustion products containing unburned fuel;(c) ejecting at least one secondary oxidant stream angled away or spaced from the fuel stream and primary oxidant stream;(d) causing a recirculating flow within the combustion zone to dilute at least a portion of the combustion products, secondary oxidant, sulfur vapor, unburned fuel and ambient gas in the furnace; and(e) combusting the sulfur vapor and the unburned fuel with said secondary oxidant.
    Type: Grant
    Filed: June 6, 1994
    Date of Patent: October 17, 1995
    Assignee: Praxair Technology, Inc.
    Inventor: Maynard G. Ding
  • Patent number: 5452583
    Abstract: A system and process for recovering high purity coolant gas from at least one fiber optic heat exchanger, characterized by controlling a flow of coolant gas into and out of the heat exchanger using a pressure, impurity and/or flow rate monitoring or transmitting means in conjunction with a flow adjusting or controlling device to limit air or other gas infiltration into at least one fiber optic passageway of the heat exchanger. A sealing means may also be used at at least one end of the fiber optic passageway to further reduce air or other gas infiltration into the passageway. The resulting high purity coolant gas from the outlet of the heat exchanger is delivered to the inlet of the heat exchanger. Optionally, the resulting coolant gas from the outlet of the heat exchanger may be cooled, filtered and/or purified before being delivered to the inlet of the heat exchanger.
    Type: Grant
    Filed: September 8, 1994
    Date of Patent: September 26, 1995
    Assignee: Praxair Technology, Inc.
    Inventor: Thomas R. Schulte
  • Patent number: 5411662
    Abstract: The invention relates to a hollow fiber membrane fluid separation assembly having an integral purge control valve or a purge fluid reflux system, which provides a sweep fluid port internal to the assembly. This assembly is useful for, among other things, separating water vapor from a gas stream.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: May 2, 1995
    Assignee: Praxair Technology, Inc.
    Inventors: Patrick S. Nicolas, Jr., Benjamin Bikson, Salvatore Giglia, David R. Thompson
  • Patent number: 5401866
    Abstract: The invention relates to a process for recovering heat from deodorized edible oils and stabilizing the same comprising: introducing or injecting non-condensible inert gas into hot deodorized edible oil as the hot deodorized edible oil is cooled by indirectly heat exchanging with crude oil to be deodorized.
    Type: Grant
    Filed: January 7, 1994
    Date of Patent: March 28, 1995
    Assignee: Praxair Technology, Inc.
    Inventors: Alan T. Y. Cheng, Jose R. Calvo, Ramon R. Barrado
  • Patent number: 5393220
    Abstract: Processes and apparatus for combusting fluid fuel, e.g., liquid fuel, in at least two combustion zones, wherein the fluid fuel is partially combusted with a fluid fuel atomizing or dispersing fluid containing oxygen in an initial combustion zone and is completely combusted with oxidant in at least one subsequent combustion zone.
    Type: Grant
    Filed: December 6, 1993
    Date of Patent: February 28, 1995
    Assignee: Praxair Technology, Inc.
    Inventors: Ludo J. C. Couwels, Eddy J. A. Lauwers
  • Patent number: 5390500
    Abstract: A cryogenic liquid vaporizer system 10 comprising an outer tube 22 for exposure to the atmosphere and enclosing an inner tube 16 to form an annulus 36. The fluid enters the inner tube 16 as liquid, flows in the inner tube 16 where it is at least partially vaporized, and discharges into the outer tube 22. In one embodiment the fluid discharges near the end 34 of the outer tube 22 and counterflow in the annulus 36 where it is usually completely vaporized and partially superheated. In another embodiment, the fluid discharges into the outer tube 22 and continues to flow in the longitudinal space 38 provided by the length of outer tube 22. The annulus 36 is occupied by quiescent fluid.
    Type: Grant
    Filed: December 29, 1992
    Date of Patent: February 21, 1995
    Assignee: Praxair Technology, Inc.
    Inventors: Norman H. White, Boris Pevzner, Thomas D. High
  • Patent number: 5391358
    Abstract: Processes and systems for purifying high purity helium group gas which may have been contaminated with water, oxygen and/or hydrogen during its transmission to customers' sites.
    Type: Grant
    Filed: August 21, 1992
    Date of Patent: February 21, 1995
    Assignee: Praxair Technology, Inc.
    Inventor: Carl J. Heim
  • Patent number: 5386706
    Abstract: A low heat-leak cryogenic system comprising a cryogenic fluid, a first lamina having an external side facing toward and exposed directly to, or indirectly to, the cryogenic fluid and an internal side facing away from the cryogenic fluid; a second lamina spaced apart from the first lamina, and at least one block or layer of coherent aerogel extending from the first lamina to the second lamina. In another version, the aerogel is in a gaseous environment having a pressure not greater than 250,000 micrometers of mercury. In another version, at least one of the lamina is flexible so as to at least partially transmit an external load, such as that imposed by the atmosphere, to the coherent aerogel, and the coherent+ aerogel is capable of at least partially transmitting a load imposed on it from one lamina to the other.
    Type: Grant
    Filed: June 10, 1993
    Date of Patent: February 7, 1995
    Assignee: Praxair Technology, Inc.
    Inventors: Victor E. Bergsten, John Notaro, Richard B. Mazzarella, Christian F. Gottzmann
  • Patent number: 5386707
    Abstract: A method for withdrawing from a vessel pressurized cryogenic helium fluid with an objectionable impurity concentration of less than 5 ppmv. The method comprises pressurizing at or near the top of the vessel with helium fluid from an external source having a concentration of up to 1000 ppmv of the objectionable impurity, and withdrawing from a port near the bottom of a vessel helium fluid at a cryogenic temperature below the temperature at which the withdrawn fluid has an objectionable impurity of 5 ppmv.
    Type: Grant
    Filed: December 31, 1992
    Date of Patent: February 7, 1995
    Assignee: Praxair Technology, Inc.
    Inventors: Thomas R. Schulte, Robert E. Goelz, Jr.
  • Patent number: 5383956
    Abstract: The present invention relates to processes and apparatuses for starting up and shutting down membrane gas separation systems comprising at least one gas separation membrane module and at least one membrane dryer module.
    Type: Grant
    Filed: October 12, 1993
    Date of Patent: January 24, 1995
    Assignee: Praxair Technology, Inc.
    Inventors: Ravi Prasad, Pauline J. Cook
  • Patent number: 5377491
    Abstract: A system and process for recovering high purity coolant gas from at least one fiber optic heat exchanger, characterized by controlling a flow of coolant gas into and out of the heat exchanger using a pressure, impurity and/or flow rate monitoring or transmitting means in conjunction with a flow adjusting or controlling device to limit air or other gas infiltration into at least one fiber optic passageway of the heat exchanger. A sealing means may also be used at at least one end of the fiber optic passageway to further reduce air or other gas infiltration into the passageway. The resulting high purity coolant gas from the outlet of the heat exchanger is delivered to the inlet of the heat exchanger. Optionally, the resulting coolant gas from the outlet of the heat exchanger may be cooled, filtered and/or purified before being delivered to the inlet of heat exchanger.
    Type: Grant
    Filed: December 11, 1992
    Date of Patent: January 3, 1995
    Assignee: Praxair Technology, Inc.
    Inventor: Thomas R. Schulte
  • Patent number: 5374751
    Abstract: The invention relates to a process for deodorizing edible oils and/or fats comprising: heating edible oil and/or fat to an elevated temperature; introducing or injecting non-condensible inert gas into said edible oil and/or fat to strip or remove substances that impart disagreeable odor and taste to said edible oil and/or fat; and recovering the resulting deodorized edible oil and/or fat, wherein an amount of said non-condensible inert gas introduced or injected is substantially less than the theoretically required amount for deodorizing said edible oil and/or fat. The condensible gas may be preheated before its introduction into the edible oil and/or fat.
    Type: Grant
    Filed: June 22, 1993
    Date of Patent: December 20, 1994
    Assignee: Praxair Technology, Inc.
    Inventors: Alan T. Y. Cheng, Jose R. Calvo, Ramon R. Barrado
  • Patent number: 5363782
    Abstract: Apparatus and process for improving atomization and combustion of fuel containing solid particles, wherein the fuel containing solid particles is ejected from an outlet port having a conical or trumpet end-like internal wall surface and a fuel atomizing fluid is ejected from a plurality of bores present in the conical or trumpet end-like internal wall surface of the outlet port.
    Type: Grant
    Filed: December 6, 1993
    Date of Patent: November 15, 1994
    Assignee: Praxair Technology, Inc.
    Inventor: Ludo J. C. Couwels
  • Patent number: 5363779
    Abstract: The invention relates to combusting contaminants on foundry sand in a container (13) rotating about an axis (A) at a particular angle with a particularly placed oxygen-fuel burner (32). As the container (13) rotates about the axis (A), the oxygen-fuel burner (32) fires a flame and excess oxygen at a particular angle to enhance pyrolysis of the contaminants. The amount of excess oxygen is such that the resulting off gas contains at least 2% oxygen by volume, thus preventing or substantially minimizing products of incomplete combustion from leaving the container (13). After having pyrolyzed the contaminants, the firing of a flame and excess oxygen from the oxygen-fuel burner (32) may be replaced with oxidant dispersion an the bottom of the foundry sand. The resulting off gas from the container (13) may be treated in a post combustion furnace (7), a flue gas cooling means (8), a filtering device (9) and/or a pollutant removing means (11).
    Type: Grant
    Filed: December 1, 1993
    Date of Patent: November 15, 1994
    Assignee: Praxair Technology, Inc.
    Inventor: Roland P. A. G. Bury
  • Patent number: 5364454
    Abstract: The present invention relates to fluid separation composite membranes prepared from sulfonated aromatic polymers in lithium salt form with sulfonic acid groups attached to aromatic rings that are incorporated into the main polymeric backbone.
    Type: Grant
    Filed: June 30, 1993
    Date of Patent: November 15, 1994
    Assignee: Praxair Technology, Inc.
    Inventors: Benjamin Bikson, Joyce K. Nelson
  • Patent number: 5360603
    Abstract: The present invention relates to processes and apparatus for mixing oxidizable reactants with oxidant and/or oxidizing oxidizable reactants. Through using particular mixing and/or oxidizing arrangements, the risk of flammable or explosive reactions can be significantly reduced or prevented. When ammonia is used as the reactant, nitric acid can be obtained.
    Type: Grant
    Filed: August 23, 1993
    Date of Patent: November 1, 1994
    Assignee: Praxair Technology, Inc.
    Inventors: Raymond F. Drnevich, Douglas R. Dreisinger