Patents by Inventor Ravi Prasad

Ravi Prasad has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6649235
    Abstract: A method for producing a coated polymeric article by co-extruding polypropylene and a maleic anhydride modified polypropylene, corona-treating, and applying a polysilicate barrier is described. Also provided are films and bottles produced using this method.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: November 18, 2003
    Assignee: Hoechst Trespaphan GmbH
    Inventor: Ravi Prasad
  • Patent number: 6638575
    Abstract: Oxygen and hydrogen transport membranes fabricated by plasma spray deposition of a micro-crack-free coating on a substrate. Also disclosed is a multi-layer composite comprising a dense or porous substrate coated with a coating provided by supersonic plasma spray deposition. Also disclosed is subsonic plasma spray deposition of single phase or dual phase nanocrystalline particles to form a crack-free oxygen transport membrane on a substrate.
    Type: Grant
    Filed: July 24, 2000
    Date of Patent: October 28, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Jack Chieh-Cheng Chen, Hancun Chen, Ravi Prasad, Glenn Whichard
  • Publication number: 20030194369
    Abstract: A gas generation system includes a chemical reactor integrated with a liquid/gas separator. The reactor is configured to receive a continuous stream of aqueous solution.
    Type: Application
    Filed: April 16, 2002
    Publication date: October 16, 2003
    Inventors: Ravi Prasad, John A. Devos, Philip Harding, Joseph W. Tsang
  • Publication number: 20030194368
    Abstract: A hydrogen production system includes a reactor having an inlet and an outlet and a catalyst disposed in the reactor.
    Type: Application
    Filed: April 16, 2002
    Publication date: October 16, 2003
    Inventors: John A. Devos, Philip Harding, Ravi Prasad, Joseph W. Tsang
  • Publication number: 20030143443
    Abstract: Two co-catalysts selected from the transitional metals can be employed in proton exchange membrane fuel cells to catalyze a borohydride anolyte, such that diatomic hydrogen produced on the surface of a particle of a first catalyst is diffused to an adjacent surface of a particle of a second catalyst. At the second catalyst the diatomic hydrogen is catalyzed to produce hydrogen ions, which are employed as the mobile ion transported across the electrolyte concurrent with the generation of electrical current. The apparatus operates without the accumulation of hydrogen gas, except as adhered to the surface of the two catalysts.
    Type: Application
    Filed: January 28, 2002
    Publication date: July 31, 2003
    Inventors: Joseph W. Tsang, Ravi Prasad
  • Publication number: 20030134058
    Abstract: A method for producing a coated polymeric article by co-extruding polypropylene and a maleic anhydride modified polypropylene, corona-treating, and applying a polysilicate barrier is described. Also provided are films and bottles produced using this method.
    Type: Application
    Filed: August 17, 1998
    Publication date: July 17, 2003
    Inventor: RAVI PRASAD
  • Publication number: 20030134161
    Abstract: A protective case is disclosed that has a preventative agent disposed therein for safely housing an object or material with an adverse characteristic such as high heat or volatility is disclosed. The preventative agent normalizes the adverse characteristic from the object or material before that characteristic can reach the outside environment.
    Type: Application
    Filed: October 28, 2002
    Publication date: July 17, 2003
    Inventors: Makarand P. Gore, L. Chris Mann, Lawrence R. Plotkin, Ravi Prasad, Richard B. Peterson
  • Publication number: 20030134097
    Abstract: A barrier film for separating liquid and air, including a liquid crystalline polymer layer having a glass transition temperature less than about 115° C., and having a thickness less than about 15 microns. The barrier film further including a heat-sealable layer, and an adhesive layer interposed between the liquid crystalline polymer layer and the heat sealable layer, forming the barrier film.
    Type: Application
    Filed: January 17, 2003
    Publication date: July 17, 2003
    Inventor: Ravi Prasad
  • Patent number: 6575170
    Abstract: A process for exapanding tobacco employs gaseous impregnant at elevated pressure. Tobacco is passed through a gaseous impregnant atmosphere using mechanical devices (e.g., pressure locks, pocket feeders). Tobacco gets impregnated with pressurized gaseous impregnant during the “pass-through”. Uniformity of impregnation is obtained by passing small batches of tobacco having uniform bulk density, and uniform gas properties at or near the tobacco exit point of the “Pass-through”. Natural buoyancy of the impregnant gas assures that gas temperature uniformity is achieved quickly and without any elaborate control system, and in a simplified, self controlling and self regulating process. Significant equipment cost and size reduction results. An apparatus that uses the improved process is also provided. For carbon dioxide impregnated tobacco, expansion occurs when the impregnated tobacco is subjected to conditions that cause rapid release of the impregnated gas.
    Type: Grant
    Filed: November 27, 2000
    Date of Patent: June 10, 2003
    Inventor: Ravi Prasad
  • Patent number: 6565632
    Abstract: An ion-transport membrane assembly including a tubular, ion-transport membrane that is fabricated from one or more ion-transport, ceramic materials capable of ionic transport at an operational temperature of greater than 400° C. The membrane may be an oxygen transport membrane or a hydrogen transport membrane. A plurality of structural supporting members, fabricated from an open porous material and having an outer cylindrical surface, are inserted within the membrane, without being bonded to the membrane, to inhibit inward collapse of the membrane under application of a pressure applied to an exterior surface of the membrane. The structural supporting members are configured to permit relative movement between the outer surface of the structural supporting member and the interior surface of the tubular membrane during heating to or cooling from the operational temperature thereof.
    Type: Grant
    Filed: December 17, 2001
    Date of Patent: May 20, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Bart Antonie van Hassel, Ravi Prasad, Jack Chen, Jonathan Lane
  • Publication number: 20030082427
    Abstract: The present invention concerns a fuel supply for a fuel cell. The fuel supply includes a fuel storage area configured to hold a fuel solution, a fuel solution outlet configured to pass the fuel solution from the fuel storage area, a waste storage area, a waste inlet configured to pass waste into the waste storage area, and a movable barrier separating the fuel storage area and the waste storage area. The movable barrier is configured to move as fuel solution is passed from the fuel storage area and waste solution is passed into the waste storage area to simultaneously decrease the volume of the fuel storage area and increase the volume of the waste storage area.
    Type: Application
    Filed: October 29, 2001
    Publication date: May 1, 2003
    Inventors: Ravi Prasad, Qin Liu, Loren E. Johnson, Michael L. Bullock, Winthrop D. Childers, L. Chris Mann, Joseph W. Tsang
  • Publication number: 20030081090
    Abstract: In one embodiment of the invention, a structure for preventing ink shorting of conductors connected to a printhead is provided. The structure includes a layer of insulating material shaped to at least partially encapsulate the conductors on the printhead. The insulating material includes a first surface and a second surface, with each of the surfaces having an adhesive coated thereon. The adhesive includes a polymer of ethylene and glycidyl methacrylate. The adhesive may also further include an acrylic ester. Alternatively, a first adhesive may be coated onto a first surface of the insulating material or coverlayer and a second adhesive (distinct in composition from the first adhesive) may be coated onto a second surface of the insulating material or coverlayer.
    Type: Application
    Filed: October 31, 2001
    Publication date: May 1, 2003
    Inventors: David L. Erickson, Gary J. Watts, Ravi Prasad
  • 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: 6539719
    Abstract: An oxygen selective ion transport membrane is integrated with a boiler furnace to generate steam and, optionally, high purity oxygen and nitrogen. The heat required to drive the system is obtained by the combustion of an oxygen transported through the oxygen selective ion transport membrane with a high BTU fuel such as methane or natural gas. NOx compound formation is minimized either by utilizing a combustion products diluted air/fuel mixture for combustion in the boiler furnace or by limiting combustion to a mixture of oxygen and a fuel.
    Type: Grant
    Filed: October 26, 2001
    Date of Patent: April 1, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Ravi Prasad, Hisashi Kobayashi, Pauline Jane Cook
  • Patent number: 6537514
    Abstract: In a method for the production of carbon dioxide, an oxygen-containing first process gas is flowed along a cathode side of a first oxygen selective ion transport membrane. The membrane is at operating conditions effective to transport a first permeate oxygen portion from the cathode side to an opposite anode side. A carbon-containing second process gas is flowed along the anode side at a flow rate effective to provide a stoichiometric surplus of oxygen on combination with the first permeate oxygen portion. A first mixture of a second process gas and the first permeate oxygen portion is combusted such that substantially all of the second process gas is converted into a second mixture of water and carbon dioxide. The carbon dioxide is separated from such second mixture.
    Type: Grant
    Filed: October 26, 1999
    Date of Patent: March 25, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Ravi Prasad, Christian Friedrich Gottzmann, Nitin Ramesh Keskar, Joseph Michael Schwartz
  • Patent number: 6537465
    Abstract: Methane is formed into synthesis gas through a combination of a partial oxidation reaction and a steam reforming reaction. Oxygen for the partial oxidation reaction is obtained by contacting air with an oxygen transport membrane and recovering the oxygen transported through the membrane. To increase the oxygen flux through the membrane, steam is utilized as a sweep gas on the anode side of the membrane. The steam reduces the oxygen partial pressure on the anode side increasing the flux. The efficiency and cost benefit of the process is enhanced by utilizing in-line combustors to heat gases being delivered to the oxygen transport membrane. Membrane integrity is enhanced by conducting the reactions in a reactor that is remote from the oxygen transport membrane.
    Type: Grant
    Filed: December 29, 2000
    Date of Patent: March 25, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Christian Friedrich Gottzmann, Ravi Prasad, Joseph Michael Schwartz
  • Patent number: 6524421
    Abstract: A cold isopressing method in which two or more layers of material are formed within an isopressing mold. One of the layers consists of a tape-cast film. The layers are isopressed within the isopressing mold, thereby to laminate the layers and to compact the tape-cast film. The isopressing mold can be of cylindrical configuration with the layers being coaxial cylindrical layers. The materials used in forming the layers can contain green ceramic materials and the resultant structure can be fired and sintered as necessary and in accordance with known methods to produce a finished composite, ceramic structure. Further, such green ceramic materials can be of the type that are capable of conducting hydrogen or oxygen ions at high temperature with the object of utilizing the finished composite ceramic structure as a ceramic membrane element.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: February 25, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Jack C. Chen, Valerie M. Stawisuck, Ravi Prasad
  • Publication number: 20030008966
    Abstract: The preparation and usefulness of polymer-ceramic mixed matrix composite materials comprising one or more organic polymers and a nano sized dispersion of inorganic metal oxide particles throughout the polymer(s) are described. The mixed matrix materials are used as mass transfer agents by fabricating the matrix materials into thin membranes and using them to dehydrate organic streams by pervaporation/vapor permeation separation processes. In addition, mixed matrix gels of similar composition are prepared in a variety of shapes and show a remarkable degree of reversible water absorbing properties. Mechanical and physical properties of the gels, such as extent of swelling in water, can be controlled by controlling the mixed matrix material composition.
    Type: Application
    Filed: May 15, 2002
    Publication date: January 9, 2003
    Inventors: Leland Morris Vane, Ravi Prasad Ponangi
  • Publication number: 20020155061
    Abstract: A method of producing a crude syngas product stream or a syngas product stream by further processing of the crude syngas product stream. Both the crude and syngas product stream comprise carbon monoxide and hydrogen. The crude syngas product stream additionally comprises carbon dioxide and moisture. In accordance with the method, methane in a feed stream is converted into the hydrogen and carbon monoxide in at least two stages, thereby to form a crude syngas stream. An initial stage has an oxygen transport membrane reactor having a catalyst to promote carbon dioxide or steam methane reforming. Since, the conversion is shared between two stages, the oxygen transport membrane reactor can be operated at a sufficiently low temperature to avoid ceramic membrane deterioration due to creep effect. The subsequent stage can be operated at a higher temperature with more favorable equilibrium conditions to complete the conversion of the methane.
    Type: Application
    Filed: April 24, 2001
    Publication date: October 24, 2002
    Inventors: Ravi Prasad, Joseph Michael Schwartz, Earl T. Robinson, Christian Friedrich Gottzmann
  • Patent number: 6457820
    Abstract: A printer has a print engine with an ink supply chamber connected to the print engine. The supply chamber has an exit aperture to which a suction device is connected. A gas permeable film associated with the aperture separates the chamber from the suction device. The suction device may be a resilient spring member that occasionally is composed during winter carriage reciprocation to maintain suction, or may be a vacuum pump. A porous may support the film.
    Type: Grant
    Filed: June 19, 2001
    Date of Patent: October 1, 2002
    Assignee: Hewlett-Packard Company
    Inventors: Edward Z. Cai, Ravi Prasad, Isaac Farr, Jenny Li