Maulik R Shelat

US Patent:

20100192628, Aug 5, 2010

Filed:

Dec 29, 2009

Appl. No.:

12/648775

Inventors:

Richard John Jibb - Amherst NY, US
Maulik R. Shelat - Katy TX, US
Lyda Zambrano - Buffalo NY, US

International Classification:

F25J 3/00
F28F 3/08

US Classification:

62640, 165166

Abstract:

The present invention relates to an apparatus and air separation plant in which a pumped liquid oxygen stream is heated within a heat exchanger through indirect heat exchange with compressed air to produce an oxygen product. The liquid oxygen stream is pressurized in a range above about 55 bar(a) and no greater than about 150 bar(a) and is a supercritical fluid after having been heated within the heat exchanger. The air is compressed to an air pressure that is a function of the oxygen pressure that will result in a minimum power being expended in the compression of the air. The heat exchanger can be a brazed fin heat exchanger fabricated from aluminum in which the fins located in heat exchange passages have an undulating configuration to increase the flow path length and induce flow separation and thereby increase the heat transfer coefficient within the heat exchanger.

US Patent:

20100192629, Aug 5, 2010

Filed:

Jan 30, 2009

Appl. No.:

12/363279

Inventors:

Richard John Jibb - Amherst NY, US
Maulik R. Shelat - Katy TX, US
Lyda Zambrano - Buffalo NY, US

International Classification:

F25J 3/00

US Classification:

62654

Abstract:

The present invention relates to a method of producing an oxygen product by heating a pumped liquid oxygen stream within a heat exchanger through indirect heat exchange with compressed air. The liquid oxygen stream is pressurized to an oxygen pressure in a range above about 55 bar(a) and no greater than about 150 bar(a) and heated within the heat exchanger to form a supercritical fluid. The air is compressed to an air pressure upon entering the heat exchanger that is a function of the oxygen pressure that will result in a minimum power being expended in the compression of the air. The heat exchanger can be a brazed fin heat exchanger fabricated from aluminum in which the fins located in heat exchange passages have an undulating configuration to increase the flow path length and induce flow separation and thereby increase the heat transfer coefficient within the heat exchanger.

US Patent:

20140000841, Jan 2, 2014

Filed:

Jun 29, 2012

Appl. No.:

13/538387

Inventors:

Robert L. Baker - Williamsville NY, US
Arun Suryanarayanan - Tonawanda NY, US
Maulik R. Shelat - Williamsville NY, US
Jeffrey C. Goodband - Niagara Falls NY, US

International Classification:

F25B 29/00

US Classification:

165 59

Abstract:

A compressed gas cooling apparatus in which gas from an upstream compression stage enters an inlet section from an inlet opening and flows to a heat exchanger that cools the gas. The cooled gas then flows from the heat exchanger to the outlet section where the gas is discharged from an outlet opening. Pressure drop within the apparatus is decreased by providing the inlet and outlet sections with ever increasing and decreasing cross-sectional flow areas. In order to further decrease pressure drop due to a swirl within the gas flow imparted from the upstream compression stage, the inlet section is provided with first and second subsections wherein the cross-sectional flow area of the first subsection increases at lesser rate than the second subjection. Alternatively, or in addition, the inlet section can be provided with partitions to divide the gas flow into subflows in order to lessen pressure drop from swirl.

US Patent:

8397535, Mar 19, 2013

Filed:

Jun 16, 2009

Appl. No.:

12/485235

Inventors:

Henry Edward Howard - Grand Island NY, US
Richard John Jibb - Wheatfield NY, US
David Ross Parsnick - Amherst NY, US
Todd Alan Skare - Madrid, ES
Maulik Shelat - Williamsville NY, US

Assignee:

Praxair Technology, Inc. - Danbury CT

International Classification:

F25J 3/02

US Classification:

62652

Abstract:

The present invention relates to a method and apparatus for producing a pressurized product stream product by cryogenic rectification. A main heat exchanger, used in the cryogenic rectification, warms a pumped product stream composed of oxygen-rich or nitrogen-rich liquid and thereby produces the pressurized product stream. Layers of the main heat exchanger are designed such that a reduction in the heat transfer area provided within the main heat exchanger for warming the pumped product stream occurs at a location at which the temperature of the pumped product stream exceeds either the critical or a dew point temperature of such stream. The reduction in heat transfer area leaves regions of the layers able to heat or cool another stream that is used in connection with the cryogenic rectification. Such other stream can be a refrigerant stream that allows the introduction of additional refrigeration to increase production of liquid products.

US Patent:

20220290815, Sep 15, 2022

Filed:

Nov 2, 2021

Appl. No.:

17/516984

Inventors:

Hanfei Tuo - East Amherst NY, US
Chao Liang - East Amherst NY, US
Maulik R. Shelat - Williamsville NY, US
Sang Muk Kwark - Holly Springs NC, US
Seth A. Potratz - Grand Island NY, US

International Classification:

F17C 9/02

Abstract:

A cryogenic vaporization system and method are provided. A first heat exchanger heats a liquid cryogen via indirect heat exchange to output a cryogenic vapor at a first temperature. A second heat exchanger receives the cryogenic vapor at the first temperature. The second heat exchanger heats the cryogenic vapor via indirect heat exchange to a second temperature. The cryogenic vapor at the second temperature is recirculated to the first heat exchanger to heat the liquid cryogen and cool the recirculated cryogenic vapor to a third temperature. A third heat exchanger receives the cryogenic vapor at the third temperature. The third heat exchanger heats the cryogenic vapor to a fourth temperature. The third heat exchanger outputs the cryogenic vapor at the fourth temperature.

US Patent:

20230070799, Mar 9, 2023

Filed:

Dec 18, 2020

Appl. No.:

17/790161

Inventors:

- Danbury CT, US
Sadashiv M. Swami - Williamsville NY, US
Maulik R. Shelat - Macungie PA, US
Ines C. Stuckert - Grand Island NY, US
Steven M. Brown - Amherst NY, US
Shrikar Chakravarti - East Amherst NY, US
Juan Li - Clarence NY, US
Digna Vora - Buffalo NY, US

International Classification:

C01B 3/38
C01B 3/48
C01B 13/02

Abstract:

A method and system for decarbonization of a hydrocarbon conversion process such as steam methane reforming process for hydrogen production utilizing oxygen transport membrane reactors. The system employs catalyst-containing reforming reactors for converting natural gas into synthesis gas which is further treated in high temperature or medium temperature water gas shift reactors and fed to a hydrogen PSA to produce hydrogen product. The system further employs oxygen transport membrane reactors thermally coupled to reforming reactors and configured to oxy-combust about 90% to about 95% of combustibles in PSA tail gas that may be optionally mixed with natural gas. The oxy-combustion product stream leaving the oxygen transport membrane reactors contains about 90% of the carbon provided to the feed of the reforming reactor. The carbon dioxide in the oxy-combustion product stream can be recovered and further purified for utilization or geologic storage or liquefied to form a liquid carbon dioxide product.

US Patent:

20200333050, Oct 22, 2020

Filed:

Jul 7, 2020

Appl. No.:

16/922067

Inventors:

Neil M. Prosser - Lockport NY, US
James R. Dray - Buffalo NY, US
Paul W. Belanger - Clarence Center NY, US
Maulik R. Shelat - Williamsville NY, US

International Classification:

F25B 9/02
F25B 9/10
F25J 1/00
F25J 1/02
F25B 25/00
B64G 1/40
F25B 40/00

Abstract:

Closed-loop refrigeration cycles for liquid oxygen densification are disclosed. The disclosed refrigeration cycles may be turbine-based refrigeration cycles or a Joule-Thompson (JT) expansion valve based refrigeration cycles and include a refrigerant or working fluid comprising a mixture of neon or helium together with nitrogen and/or oxygen.

US Patent:

20200080773, Mar 12, 2020

Filed:

Sep 7, 2018

Appl. No.:

16/124636

Inventors:

Zhengrong Xu - East Amherst NY, US
Maulik R. Shelat - Williamsville NY, US
Nick J. Degenstein - The Woodlands NY, US
Hanfei Tuo - East Amherst NY, US

International Classification:

F25J 3/04

Abstract:

A cryogenic air separation unit that provides flexibility in the production of liquid products is disclosed. The present cryogenic air separation unit and associated operating methods involves the use of a dual nozzle arrangement for the main heat exchanger that allows a turbine air stream draw from the main heat exchanger at different temperatures to provide refrigeration to the cryogenic air separation unit which, in turn, enables different production modes for the various liquid products.