Patents by Inventor Alan Tat Yan Cheng

Alan Tat Yan Cheng 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: 7279319
    Abstract: A sparger for delivering fluid comprising a sparger pipe for carrying the fluid from a fluid source and downwardly directed nozzles to direct the delivery of fluid is disclosed. A substantially vertical connection pipe connects the sparger to the nozzles. Also, a method of delivering oxygen to an oxygen-depleted zone in the bottom of the fermenter using the sparger is disclosed.
    Type: Grant
    Filed: November 12, 2004
    Date of Patent: October 9, 2007
    Assignee: Praxair Technology, Inc.
    Inventor: Alan Tat-Yan Cheng
  • Patent number: 7048262
    Abstract: A sparger for delivering fluid including a sparger pipe for carrying the fluid from a fluid source and downwardly directed nozzles to direct the delivery of fluid is disclosed. A substantially vertical connection pipe connects the sparger to the nozzles. Also, a method of delivering oxygen to an oxygen-depleted zone in the bottom of the fermenter using the sparger is disclosed.
    Type: Grant
    Filed: November 1, 2001
    Date of Patent: May 23, 2006
    Assignee: Praxair Technology, Inc.
    Inventor: Alan Tat-Yan Cheng
  • Patent number: 6622496
    Abstract: This invention is directed to an external loop nonfreezing heat exchanger for cooling a heat transfer fluid with cryogenic fluid. The cryogenic fluid is first pre-vaporized with the spent cryogenic fluid. The heat transfer fluid is then cooled by the vaporized cryogenic fluid instead of the cryogenic fluid feed directly.
    Type: Grant
    Filed: July 12, 2001
    Date of Patent: September 23, 2003
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Donald Leonard DeVack
  • Publication number: 20030101736
    Abstract: This invention is directed to an external loop nonfreezing heat exchanger for cooling a heat transfer fluid with cryogenic fluid. The cryogenic fluid is first pre-vaporized with the spent cryogenic fluid. The heat transfer fluid is then cooled by the vaporized cryogenic fluid instead of the cryogenic fluid feed directly.
    Type: Application
    Filed: July 12, 2001
    Publication date: June 5, 2003
    Inventors: Alan Tat Yan Cheng, Donald Leonard DeVack
  • Publication number: 20030080446
    Abstract: A sparger for delivering fluid comprising a sparger pipe for carrying the fluid from a fluid source and downwardly directed nozzles to direct the delivery of fluid is disclosed. A substantially vertical connection pipe connects the sparger to the nozzles. Also, a method of delivering oxygen to an oxygen-depleted zone in the bottom of the fermenter using the sparger is disclosed.
    Type: Application
    Filed: November 1, 2001
    Publication date: May 1, 2003
    Inventor: Alan Tat-Yan Cheng
  • Patent number: 6280996
    Abstract: A method for carrying out fermentation comprising the steps of providing a vessel with elevated pressure up to 25 atm which contains a broth comprising a constituent capable of undergoing fermentation, lowering the vessel pressure within the vessel to lower the equilibrium oxygen partial pressure, adding pure oxygen into the vessel to raise the equilibrium oxygen partial pressure therein, and utilizing the pure oxygen to carry out the fermentation of the constituent.
    Type: Grant
    Filed: March 22, 1999
    Date of Patent: August 28, 2001
    Assignee: Praxair Technology, Inc.
    Inventor: Alan Tat Yan Cheng
  • Patent number: 6273402
    Abstract: An apparatus and method for mixing a gas and a liquid while concomitantly mixing and suspending solids and sludge at the bottom of a deep tank. The present invention includes a gas-liquid aerator which is adapted to be submerged below the surface of wastewater in a deep tank. An expanding high velocity gas-liquid mixture is caused to exit from the bottom of the submerged aerator device with enough force to mix and suspend settling solids and sludge at the bottom of the deep tank.
    Type: Grant
    Filed: January 10, 2000
    Date of Patent: August 14, 2001
    Assignee: Praxair Technology, Inc.
    Inventor: Alan Tat Yan Cheng
  • Patent number: 6250609
    Abstract: This invention is directed to a method of making supersaturated oxygenated liquid by introducing a high oxygen content gas to an ozone generator to produce ozone, passing the ozone to a contact tank at atmospheric pressure to produce an oxygenated and ozonated liquid, and passing the oxygenated and ozonated liquid in a contacting loop of an in-line supersonic mixer to produce a substantially pure supersaturated oxygenated and ozonated liquid.
    Type: Grant
    Filed: June 30, 1999
    Date of Patent: June 26, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Timothy Michael Lewis, Russell Steve Plancich
  • Patent number: 6220048
    Abstract: A method and apparatus for controlling the temperature of a freeze drying chamber shelves and chamber in a refrigeration system having a condenser operatively associated therewith using the circulation of a cryogen through the condenser and of a cryogenically cooled heat transfer fluid through the chamber shelves for controlling the temperature therein, and also where the temperature of the cryogenically cooled heat transfer fluid having been regulated by an exchange of heat with the cryogen.
    Type: Grant
    Filed: September 21, 1998
    Date of Patent: April 24, 2001
    Assignee: Praxair Technology, Inc.
    Inventors: Donald Stuart Finan, Sr., Alan Tat Yan Cheng
  • Patent number: 6145815
    Abstract: A system for the dissolution of gas in a large body of liquid comprising an impeller positioned below the surface of the large body of liquid; a floating hood positioned over the impeller and of sufficient size to capture undissolved gas; a conduit for introducing a feed gas stream beneath the floating hood and directly into the large body of liquid; at least one segregation ring positioned under the floating hood and extending below the surface of the large body of liquid such that a first inner region between the ring and the impeller, and a second outer region between the ring and an outer diameter of the floating hood are created, and a back pressure regulator located in the floating hood adjacent to the outer diameter of the floating hood.
    Type: Grant
    Filed: December 2, 1998
    Date of Patent: November 14, 2000
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Steven Donald Clark, Paolo Sergio Bon, Thomas John Bergman, Jr., Jeffrey Paul Kingsley, Mark Herbert Kirby, Mitchell Adis, Victor Alexander Coppola
  • Patent number: 5985652
    Abstract: A gas driven fermentation system wherein a gas such as air is passed heterogeneously upwardly through the fermentation broth to agitate and recirculate the broth, provide oxygen for fermentation and strip off carbon dioxide, and a second gas such as oxygen is passed homogeneously upwardly through the broth proximate the heterogeneous air flow to provide supplemental oxygen for fermentation.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: November 16, 1999
    Assignee: Praxair Technology, Inc.
    Inventor: Alan Tat Yan Cheng
  • Patent number: 5943869
    Abstract: Method and apparatus for effectively and safely using cryogenic liquid to cool a reactor vessel housing an exothermic reaction wherein the cryogenic liquid is subcooled, valved into the reactor in a downward direction, and shielded by annular coaxial shielding gas upon injection into the reactor.
    Type: Grant
    Filed: May 12, 1998
    Date of Patent: August 31, 1999
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Deepak Lumba
  • Patent number: 5939313
    Abstract: A method for efficiently providing supplemental oxygen to a reaction mixture which is oxidized by or otherwise uses air, wherein the reaction mixture is agitated to create one or more stationary vortices, oxygen is injected into the reactor vessel at a stationary vortex, and air bubbles are circulated within the reaction mixture in the reactor vessel and outside the stationary vortex or vortices into which the oxygen is injected.
    Type: Grant
    Filed: September 12, 1997
    Date of Patent: August 17, 1999
    Assignee: Praxair Technology, Inc.
    Inventor: Alan Tat Yan Cheng
  • Patent number: 5937656
    Abstract: A heat exchanger unit having a housing into which a cryogenic liquid is introduced and permitted to evaporate and vaporize into a cryogenic cold gas. A process fluid to be cooled flows in a heat exchanger and heat exchange to cool the process fluid takes place between the cold gas and the heat exchanger, without making direct contact between the cryogenic liquid and the heat exchanger which would cause freezing. The refrigerating capacity of the cryogenic cold gas is replenished by heat exchange contact with the evaporating cryogenic liquid.
    Type: Grant
    Filed: May 7, 1997
    Date of Patent: August 17, 1999
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Donald Leonard Devack
  • Patent number: 5802858
    Abstract: A cryogenic cooling tower in which a process liquid from which heat is to be removed is supplied to the tower interior that has a plurality of plates vertically stacked one above the other, alternating in opposite directions and tilted downwardly at an angle relative to the tower vertical axis. A cryogenic cooling medium is supplied to the tower interior. The process liquid forms a film on the upper surface of the plate and drops from its front end to the next lower plate. While on a plate the process liquid spread into a film provides a greater surface area to react with the cooling medium to effect the heat transfer. The tilt angle of the plates can be adjusted to control the residence time of the process liquid in the tower.
    Type: Grant
    Filed: March 27, 1997
    Date of Patent: September 8, 1998
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Donald Leonard Devack
  • Patent number: 5798254
    Abstract: A gas driven fermentation method is disclosed wherein a gas, such as air, is passed heterogeneously upwardly through a fermentation broth to agitate and recirculate the broth. Further, the provision of oxygen for fermentation permits the carbon dioxide to be stripped off; and in addition a second gas, such as a fluid-containing oxygen is passed homogeneously upwardly through the broth to provide for supplemental air flow for the fermentation. The heterogeneously flow is carried out at a superficial velocity greater than 0.03 meter/second (m/sec); and the homogenous flow is carried out at a superficial velocity less than 0.05 m/sec.
    Type: Grant
    Filed: September 13, 1996
    Date of Patent: August 25, 1998
    Assignee: Praxair Technology, Inc.
    Inventor: Alan Tat Yan Cheng
  • Patent number: 5763544
    Abstract: Method and apparatus for effectively and safely using cryogenic liquid to cool a reactor vessel housing an exothermic reaction wherein the cryogenic liquid is subcooled, valved into the reactor in a downward direction, and shielded by annular coaxial shielding gas upon injection into the reactor.
    Type: Grant
    Filed: January 16, 1997
    Date of Patent: June 9, 1998
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Deepak Lumba
  • Patent number: 5701745
    Abstract: A cryogenic cold shelf for use in a freeze drying system having a cryogen distributor for passing cryogenic fluid into the shelf volume of the cold shelf at differing rates so as to even refrigeration provided over the entire shelf resulting in a uniform temperature over the cold shelf.
    Type: Grant
    Filed: December 16, 1996
    Date of Patent: December 30, 1997
    Assignee: Praxair Technology, Inc.
    Inventors: Alan Tat Yan Cheng, Donald Leonard DeVack