Patents by Inventor Prasad S. Apte

Prasad S. Apte 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: 7781049
    Abstract: A hydrogen transport membrane in which a porous ceramic support supports a dense layer of palladium or an alloy of palladium serving as a hydrogen transport material. The ceramic support has a first porous layer and a second porous layer. The first porous layer has a first thickness of about 1 mm, a first set of pores have a first average pore size of between about 10 microns and about 50 microns and a first porosity of about 40 percent by volume. The second porous layer has a second thickness of about 3 microns, a second set of pores having a second average pore size of between about 10 nanometers and about 100 nanometers and a second porosity of about 50 percent by volume. The dense layer has a thickness of about 3 microns.
    Type: Grant
    Filed: March 26, 2009
    Date of Patent: August 24, 2010
    Assignee: Praxair Technology, Inc.
    Inventors: Prasad S. Apte, Joseph Michael Schwartz, Shawn W. Callahan
  • Publication number: 20090214844
    Abstract: A hydrogen transport membrane in which a porous ceramic support supports a dense layer of palladium or an alloy of palladium serving as a hydrogen transport material. The ceramic support has a first porous layer and a second porous layer. The first porous layer has a first thickness of about 1 mm, a first set of pores have a first average pore size of between about 10 microns and about 50 microns and a first porosity of about 40 percent by volume. The second porous layer has a second thickness of about 3 microns, a second set of pores having a second average pore size of between about 10 nanometers and about 100 nanometers and a second porosity of about 50 percent by volume. The dense layer has a thickness of about 3 microns.
    Type: Application
    Filed: March 26, 2009
    Publication date: August 27, 2009
    Inventors: Prasad S. Apte, Joseph Michael Schwartz, Shawn W. Callahan
  • Patent number: 7531215
    Abstract: A method of forming a hydrogen transport membrane to separate hydrogen from a hydrogen containing feed in which a porous ceramic support is formed to support a dense layer of palladium or an alloy of palladium serving as a hydrogen transport material. Isolated deposits of palladium, a palladium alloy or a component of such alloy are produced on a surface of the porous ceramic support that bridge pores within the porous ceramic support without penetrating the pores and without bridging regions of the surface defined between the pores. The isolated deposits of the metal are produced by an electroless plating process.
    Type: Grant
    Filed: November 15, 2005
    Date of Patent: May 12, 2009
    Assignee: Praxair Technology, Inc.
    Inventors: Prasad S. Apte, Joseph Michael Schwartz, Shawn W. Callahan
  • Patent number: 7279025
    Abstract: A method of separating oxygen from an oxygen containing feed and reacting the oxygen with a reactive substance and an oxygen ion transport membrane element utilized for such purposes. The oxygen ion transport membrane element has a self-supporting dense layer and a surface porous feature in contact with and supported by the dense layer. The porous surface feature may be a layer, a layer having discontinuities or a series of repeating geometrical forms. The dense layer and the porous surface feature are capable of conducting oxygen ions and electrons. The porous surface feature at least in part forms the anode side of the oxygen ion transport membrane element at which the reactive substance reacts with the separated oxygen and has a thickness less than that of the dense layer and a greater surface area than that of a surface of the dense layer adjoining the porous layer. Pores within the porous surface feature have a pore aspect ratio of pore size to pore length of between about 0.1 and about 5.
    Type: Grant
    Filed: December 21, 2004
    Date of Patent: October 9, 2007
    Assignee: Praxair Technology, Inc.
    Inventors: Prasad S. Apte, Joseph M. Schwartz, James E. White
  • Patent number: 6776941
    Abstract: A cold isopressing method and mold for compacting a granular ceramic material in which the granular ceramic material is introduced into a cylindrical pressure bearing element of an isopressing mold. The cylindrical pressure bearing element is sufficiently rigid so as to maintain its shape during the introducing of the granular ceramic material. Such element is also sufficiently resilient in a radial direction thereof to deform and bear against the granular ceramic material upon the application of the hydrostatic pressure and to substantially return to its original shape upon the relaxation of the hydrostatic pressure, thereby to allow retraction of the cylindrical pressure bearing element from the granular ceramic material after compaction. In a further aspect, an isopressing method and mold is provided in which the cylindrical pressure bearing element thereof is provided with an enlarged end bore to form an enlarged end section in the finished ceramic tube for sealing purposes.
    Type: Grant
    Filed: June 6, 2002
    Date of Patent: August 17, 2004
    Assignee: Praxair Technology, Inc.
    Inventors: Prasad S. Apte, Shawn W. Callahan, James S. Schneider, Jack C. Chen
  • Publication number: 20030039601
    Abstract: A reaction vessel for the production of synthesis gas that contains four subassemblies: (1) a first heat exchanger that transfers heat between two low pressure streams (an oxygen containing stream and an oxygen depleted stream); (2) a second heat exchanger that transfers heat between two high pressure fluid streams (a hydrocarbon-containing reactant stream and a synthesis gas product stream); (3) mixed conductor ceramic membranes; and (4) a catalyst bed. Each of these subassemblies are configured so that they freely expand or contract independently from each other, and to thus avoid inducing high mechanical loads and damaging material stresses.
    Type: Application
    Filed: August 10, 2001
    Publication date: February 27, 2003
    Inventors: Thomas Gilbert Halvorson, Victor Emmanuel Bergsten, Prasad S. Apte, Nitin Ramesh Keskar, Christo Steyn, Richard Andrew Vanslooten
  • Publication number: 20030006537
    Abstract: A cold isopressing method and mold for compacting a granular ceramic material in which the granular ceramic material is introduced into a cylindrical pressure bearing element of an isopressing mold. The cylindrical pressure bearing element is sufficiently rigid so as to maintain its shape during the introducing of the granular ceramic material. Such element is also sufficiently resilient in a radial direction thereof to deform and bear against the granular ceramic material upon the application of the hydrostatic pressure and to substantially return to its original shape upon the relaxation of the hydrostatic pressure, thereby to allow retraction of the cylindrical pressure bearing element from the granular ceramic material after compaction. In a further aspect, an isopressing method and mold is provided in which the cylindrical pressure bearing element thereof is provided with an enlarged end bore to form an enlarged end section in the finished ceramic tube for sealing purposes.
    Type: Application
    Filed: June 6, 2002
    Publication date: January 9, 2003
    Inventors: Prasad S. Apte, Shawn W. Callahan, James S. Schneider, Jack C. Chen
  • Patent number: 6372165
    Abstract: A cold isopressing method in which first and second layers of at least two layers are formed within an isopressing mold and the second of the layers is isostatically pressed against the first of the layers to compact the second layer. The layers can be formed from different materials, for instance granular materials or slurries. Each layer can additionally have different levels of materials. The granular materials can have pore formers to produce intermediate porous layers. Channel forming materials can be positioned between layers during isopressing. Alternatively, the first layers can be preformed by extrusion, slip casting or injection isopressing molding. One or more of the layers can have two or more regions of different ceramic materials.
    Type: Grant
    Filed: September 22, 2000
    Date of Patent: April 16, 2002
    Assignee: Praxair Technology, Inc.
    Inventors: Prasad S. Apte, Shawn W. Callahan
  • Patent number: 5902429
    Abstract: Novel processes are provided for the production of porous ceramic preforms, metal activated porous ceramic preforms and intermetallic/ceramic/metal composites. These products are all manufactured using processes which are based on tape casting techniques.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: May 11, 1999
    Assignee: Westaim Technologies, Inc.
    Inventors: Prasad S. Apte, Stephen F. J. Corbin
  • Patent number: 5846664
    Abstract: A process is provided for the manufacture of porous metal components. The process involves preparing a colloidal suspension comprising a metal-containing powder in admixture with a binder system, and a plasticizer in an organic solvent. Optionally, a particulate pore forming agent may be added to the suspension. The suspension is cast into a thin sheet and air dried to thereby form a tape. The tapes are layered and formed by compacting at predetermined pressures to laminate the tapes, thus forming a green body. Optionally, a second pore-forming agent may be introduced between, or associated with, the tape layers. The green body is heated at a controlled rate to form a brown body, and finally sintered under controlled conditions to produce the finished component.
    Type: Grant
    Filed: January 6, 1997
    Date of Patent: December 8, 1998
    Assignee: Westaim Technologies, Inc.
    Inventors: Christine E. Third, Stephen F. J. Corbin, Prasad S. Apte
  • Patent number: 5711833
    Abstract: A process is provided for the manufacture of thin walled ceramic structures, particularly conical or near conical shaped structures. The process involves a tape casting technique wherein a green tape is prepared from a colloidal suspension containing a ceramic powder, a binder system, a plasticizer and a solvent. The suspension is cast into a thin sheet and dried to form a pliable tape. The tape is cut into planar, shaped pieces. Non-planar components of the final structure are preformed from the cut planar tape pieces into predetermined three dimensional shapes. The planar and preformed components are sequentially assembled within a die and compacted under pressure to form a green body. The green body is subjected first, to a burnout cycle to form a brown body, and then sintered to form the unitary, cohesive, thin walled ceramic structure.
    Type: Grant
    Filed: July 25, 1995
    Date of Patent: January 27, 1998
    Assignee: Thermicedge Corporation
    Inventors: Prasad S. Apte, Ernesto S. Tachauer, Travis Kyle Solomon
  • Patent number: 5202541
    Abstract: A method of heating a workpiece assembly and a load assembly suitable for heating by the method. The method involves heating the workpiece assembly in a microwave cavity surrounded by one or more rings made of electrically conductive material. The rings fix the electrical field in such a way that uniform heating of the workpiece assembly can be achieved. Large workpieces or assemblies can be heated and, if sinterable, sintered in this way without the problems normally caused by lack of uniform fields when microwaves are used to heat large loads.
    Type: Grant
    Filed: January 28, 1991
    Date of Patent: April 13, 1993
    Assignee: Alcan International Limited
    Inventors: Mark C. L. Patterson, Raymond Y. Roy, Robert M. Kimber, Prasad S. Apte
  • Patent number: 5072087
    Abstract: A process for preparing a heat-treated body from a material (preferably a dielectric ceramic) that does not couple well with microwaves while nevertheless using microwave energy for the heating step. The process involves the use of a microwave susceptor (i.e. a material that couples well with microwaves) as a means for generating heat in the material. To avoid contamination of the final product, a susceptor is chosen which is converted, during the heating step, to a substance which is substantially the same as the material itself, both the susceptor and the material are converted to the same desired final product, or the material is converted to a substance substantially the same as the susceptor. The resulting substantially pure heat-treated (and preferably sintered) bodies can be used for a variety of purposes, e.g. as substrates for micro-electronic devices. The process can also be used for joining bodies of non-susceptor materials without contaminating the resulting joint.
    Type: Grant
    Filed: October 4, 1989
    Date of Patent: December 10, 1991
    Assignee: Alcan International Limited
    Inventors: Prasad S. Apte, Robert M. Kimber, Aniket Pant, Raymond Roy, David N. Mitchell
  • Patent number: 5010220
    Abstract: A process and apparatus for heating bodies to high temperatures at high pressures. The process involves locating the body in a chamber capable of acting as a resonant cavity for microwave radiation of a predetermined frequency. The body is then irradiated in the cavity with microwave energy of the predetermined frequency for a time sufficient to raise the temperature of the body to a suitable high temperature. Then, either subsequently or simultaneously, a fluid at high pressure is introduced into the cavity to pressurize the body. The apparatus provides the equipment necessary for the operation of the process. The process and apparatus can be used for sintering and/or hot isostatic pressing of bodies made of ceramic powders and for similar purposes.
    Type: Grant
    Filed: August 30, 1990
    Date of Patent: April 23, 1991
    Assignee: Alcan International Limited
    Inventors: Prasad S. Apte, Aniket Pant