Prasad S Apte

US Patent:

6372165, Apr 16, 2002

Filed:

Sep 22, 2000

Appl. No.:

09/668329

Inventors:

Prasad S. Apte - East Amherst NY
Shawn W. Callahan - Tonawanda NY

Assignee:

Praxair Technology, Inc. - Danbury CT

International Classification:

D04H 120

US Classification:

264112, 264122, 264259, 264635, 264667

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.

US Patent:

6395206, May 28, 2002

Filed:

Jun 5, 2000

Appl. No.:

09/586897

Inventors:

Prasad Apte - East Amherst NY
Ravi Prasad - East Amherst NY

Assignee:

Praxair Technology, Inc. - Danbury CT

International Classification:

C04B 3332

US Classification:

264 82, 264656, 264234

Abstract:

A method of removing an organic binder from a green ceramic form in which a green ceramic form is subjected to a flowing carbon dioxide containing atmosphere having a sufficiently low oxygen content to allow about 60% or more of the organic binder to be oxidized by carbon dioxide. The green ceramic form is heated to the oxidation temperature at a rate greater than about 0. 1Â C. and is maintained under oxidizing temperature conditions until at least about 90% of the organic binder oxidizes.

US Patent:

6454274, Sep 24, 2002

Filed:

Mar 15, 2001

Appl. No.:

09/809389

Inventors:

James Eric White - Amherst NY
Prasad Apte - East Amherst NY
Thomas Gilbert Halvorson - Lockport NY
Victor Emmanuel Bergsten - East Amherst NY
Ajit Yeshwant Sane - Medina OH
Terry Joseph Mazanec - Solon OH

Assignee:

Praxair Technology, Inc. - Danbury CT
BP Amoco Corporation - Chicago IL

International Classification:

F16J 1502

US Classification:

277630, 277650

Abstract:

A joint assembly for joining a ceramic membrane of tubular form to a tube sheet used in supporting the ceramic membrane within a reactor. The ceramic membrane is received within a fixture connected to the tube sheet and a follower, extending into the fixture, exerts a force on a high temperature sealing element located between the fixture and the ceramic membrane to effect a seal and to hold the ceramic membrane in place. The force can be exerted directly on the sealing element or on the ceramic membrane itself.

US Patent:

6776941, Aug 17, 2004

Filed:

Jun 6, 2002

Appl. No.:

10/162632

Inventors:

Prasad S. Apte - East Amherst NY
Shawn W. Callahan - Tonawanda NY
James S. Schneider - Akron NY
Jack C. Chen - Getzville NY

Assignee:

Praxair Technology, Inc. - Danbury CT

International Classification:

B29C 4310

US Classification:

264 71, 264544, 264570, 264109, 4254052

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.

US Patent:

6844798, Jan 18, 2005

Filed:

Nov 19, 2002

Appl. No.:

10/299964

Inventors:

Prasad Apte - East Amherst NY, US
Wendell W. Isom - Grand Island NY, US
Michael M. Litwin - Cheektowaga NY, US

Assignee:

Praxair Technology, Inc. - Danbury CT

International Classification:

H01P 108

US Classification:

333252

Abstract:

A device for efficient transmission of electromagnetic waves comprising two layers of dielectric separated by a gap or space. The layers may be uniform or laminar, orthogonal or non-orthogonal to the direction of wave propagation, and made of Teflon, quartz, polypropylene, and the like. The preferred distance between layers is an odd multiple of quarter wavelength in the environment between the layers. The preferred thickness of the layers is an odd multiple of half of the effective wavelength for the layer. The device allows over 95% efficiency for transmission into a pressurized vessel for evaporation under high pressure and temperature and does not require a cooling system. The separating space may be connected with a pressure-sensing subsystem to monitor the device's integrity and shut down the system in the event of a breach. A sleeve connecting the device to the vessel may be coated with conductive material for improved efficiency.

US Patent:

7279025, Oct 9, 2007

Filed:

Dec 21, 2004

Appl. No.:

11/017041

Inventors:

Prasad S. Apte - East Amherst NY, US
Joseph M. Schwartz - Williamsville NY, US
James E. White - Amherst NY, US

Assignee:

Praxair Technology, Inc. - Danbury CT

International Classification:

B01D 53/22

US Classification:

95 54, 96 4, 96 10, 96 11, 205763, 205764, 205765, 204295

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.

US Patent:

7332057, Feb 19, 2008

Filed:

Dec 10, 2001

Appl. No.:

10/344610

Inventors:

Wendell Isom - Grand Island NY, US
Prasad Apte - East Amherst NY, US
Arthur Edward Holmer - Rensselaerville NY, US

Assignee:

Praxair Technology, Inc. - Danbury CT

International Classification:

B01D 1/00
B01D 3/42
H05B 6/68

US Classification:

159 471, 159 44, 159DIG 26, 219679, 219702, 203 2, 203100

Abstract:

This invention is directed to a method for vaporizing a liquid by slowly evaporating the liquid from a liquid phase to a vapor phase below the boiling point of the liquid; and applying an effective amount of microwave power to maintain the slow evaporation of the liquid to produce a purified liquid.

US Patent:

7879457, Feb 1, 2011

Filed:

Feb 7, 2008

Appl. No.:

12/027651

Inventors:

Prasad Shrikrishna Apte - East Amherst NY, US
James Patrick Meagher - Buffalo NY, US
Shawn W. Callahan - Tonawanda NY, US

Assignee:

Praxair S. T. Technology, Inc. - North Haven CT

International Classification:

B32B 15/04

US Classification:

428633, 428678, 416241 R

Abstract:

This invention relates to coatings for a metal or non-metal substrate comprising (i) a thermal sprayed bondcoat layer applied to the substrate, and (ii) a thermal sprayed ceramic layer applied to the bondcoat layer; wherein said coating has a helium leak rate of less than 6×10standard cubic centimeters per second. The thermal sprayed bondcoat layer comprises an alloy of MCrAlM′ wherein M is an element selected from nickel, cobalt, iron and mixtures thereof, and M′ is an element selected from yttrium, zirconium, hafnium, ytterbium and mixtures thereof. The alloy is thermally sprayed from a powder having a mean particle size of 50 percentile point in distribution of from about 5 microns to about 100 microns. The coatings are useful for extending the service life under severe conditions, such as those associated with metallurgical vessels' lances, nozzles and tuyeres.