Patents by Inventor Cha P. Doh

Cha P. Doh 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: 8091618
    Abstract: An exchange apparatus comprised of hollow perfluorinated thermoplastic tubes fusion bonded into a perfluorinated thermoplastic material to form unified terminal end blocks is disclosed. The hollow tubes are shaped by plaiting the tubes into cords and thermally annealing the cords to set the bends of the plait. The apparatus can have a housing bonded to the unified terminal end blocks. In use a first fluid enters the hollow tubes at openings in a first unified terminal end block, flows through the lumens of the tubes, and exits the tubes through a second unified terminal end block. A second fluid enters the housing, is separated from the first fluid by the wall of the tubes, and substantially fills the space between the inner wall of the housing and the outer diameters of the hollow tubes. Energy is transferred between the first and second fluids through the tube walls.
    Type: Grant
    Filed: October 31, 2007
    Date of Patent: January 10, 2012
    Assignee: Entegris, Inc.
    Inventors: Cha P. Doh, Kwok-Shun Cheng, Alicia Briggs LaForge
  • Publication number: 20080135219
    Abstract: A heat exchanger comprising hollow thermoplastic tubes, which are fusion bonded with a thermoplastic resin to form unified terminal end blocks (32, 34), is disclosed. The hollow tubes may be shaped by plaiting or braiding the tubes into cords (70, 72) and then thermally annealing the cords (70, 72) to set the crests and bends of the plait or braid. The cords (70, 72) provide improved flow distribution of fluid about the hollow tubes in the heat exchanger. The heat exchanger is chemically inert and is useful for cross-flow filtration, as well as for heat- and mass-transfer applications in harsh chemical environments.
    Type: Application
    Filed: October 31, 2007
    Publication date: June 12, 2008
    Inventors: Cha P. Doh, Kwok-Shun Cheng, Alicia Briggs LaForge
  • Patent number: 7347937
    Abstract: A filtration cartridge having a housing with an inlet and an outlet and a filtration membrane contained within the housing and located between the inlet and the outlet is described. The membrane is sealed in such a manner that all fluid must flow through the membrane between entering the inlet and leaving the outlet of the housing. The entire cartridge, housing, membrane and any other components are all formed of one or more perfluorinated thermoplastic resins. These resins preferably are PFA, MFA, FEP and blends thereof. The membrane may be in the form of hollow fibers, wound fibers such as in a depth filter, or a flat sheet which may be formed into various configurations such as spiral filters, pleated filters, spiral pleated filters, disks and the like. These cartridges provide an inert, high temperature and acid/oxidative chemical resistant filter having properties similar to that of PTFE resins.
    Type: Grant
    Filed: January 28, 2000
    Date of Patent: March 25, 2008
    Assignee: Entegris, Inc.
    Inventors: Kwok-Shun Cheng, Cha P. Doh, Larry Y. Yen, Rajnikant B. Patel, T. Dean Gates
  • Patent number: 7308932
    Abstract: An exchange apparatus comprised of hollow thermoplastic tubes infusion bonded into a thermoplastic material is disclosed. In a preferred embodiment the hollow tubes are shaped by plaiting the tubes into cords and then thermally annealing the cords to set the crests and bends of the plait. The cords provide improved flow distribution of fluid about the hollow tube tubes in the exchange apparatus. The exchange apparatus is chemically inert and is useful for cross flow filtration, as well as heat and mass transfer in harsh chemical environments.
    Type: Grant
    Filed: September 26, 2002
    Date of Patent: December 18, 2007
    Assignee: Entegris, Inc.
    Inventors: Cha P. Doh, Kwok-Shun Cheng, Alicia Briggs LaForge
  • Publication number: 20040251010
    Abstract: An exchange apparatus comprised of hollow thermoplastic tubes infusion bonded into a thermoplastic material is disclosed. In a preferred embodiment the hollow tubes are shaped by plaiting the tubes into cords and then thermally annealing the cords to set the crests and bends of the plait. The cords provide improved flow distribution of fluid about the hollow tube tubes in the exchange apparatus. The exchange apparatus is chemically inert and is useful for cross flow filtration, as well as heat and mass transfer in harsh chemical environments.
    Type: Application
    Filed: March 10, 2004
    Publication date: December 16, 2004
    Inventors: Cha P Doh, Kwok-Shun Cheng, Alicia Briggs LaForge
  • Patent number: 6805731
    Abstract: A fully perfluorinated thermoplastic hollow fiber membrane fluid-fluid contactor and a process for manufacturing the contactor is described. The contactor has a unitary end structure produced by a single step potting and bonding process. The contactor can be operated with low surface tension liquids and in harsh chemical environments.
    Type: Grant
    Filed: March 6, 2003
    Date of Patent: October 19, 2004
    Assignee: Mykrolis Corporation
    Inventors: Kwok-Shun Cheng, Cha P. Doh
  • Publication number: 20040094466
    Abstract: A method for producing a filter element of a plurality of hollow fiber membranes made of perfluorinated thermoplastic polymer with a pot or seal made of perfluorinated thermoplastic polymer. A bundle of hollow fiber membranes is prepared with the fibers substantially aligned, with at least one end sealed. The sealed end is placed in a temporary recess made in a molten pool of perfluorinated thermoplastic potting material and held in the molten pool while potting material flows around and up the fibers to form a unified pot after cooling and solidification of the potting material.
    Type: Application
    Filed: November 7, 2003
    Publication date: May 20, 2004
    Inventors: Kwok-Shun Cheng, Cha P. Doh
  • Patent number: 6663745
    Abstract: A method for producing a filter element of a plurality of hollow fiber membranes made of perfluorinated thermoplastic polymer with a pot or seal made of perfluorinated thermoplastic polymer. A bundle of hollow fiber membranes is prepared with the fibers substantially aligned, with at least one end sealed. The sealed end is placed in a temporary recess made in a molten pool of perfluorinated thermoplastic potting material and held in the molten pool while potting material flows around and up the fibers to form a unified pot after cooling and solidification of the potting material.
    Type: Grant
    Filed: July 26, 2001
    Date of Patent: December 16, 2003
    Assignee: Mykrolis Corporation
    Inventors: Kwok-Shun Cheng, Cha P. Doh
  • Publication number: 20030192428
    Abstract: A fully perfluorinated thermoplastic hollow fiber membrane fluid-fluid contactor and a process for manufacturing the contactor is described. The contactor has a unitary end structure produced by a single step potting and bonding process. The contactor can be operated with low surface tension liquids and in harsh chemical environments.
    Type: Application
    Filed: March 6, 2003
    Publication date: October 16, 2003
    Applicant: Mykrolis Corporation
    Inventors: Kowk-Shun Cheng, Cha P. Doh
  • Patent number: 6582496
    Abstract: A fully perfluorinated thermoplastic hollow fiber membrane fluid-fluid contactor and a process for manufacturing the contactor is described. The contactor has a unitary end structure produced by a single step potting and bonding process. The contactor can be operated with low surface tension liquids and in harsh chemical environments.
    Type: Grant
    Filed: July 24, 2001
    Date of Patent: June 24, 2003
    Assignee: Mykrolis Corporation
    Inventors: Kwok-Shun Cheng, Cha P. Doh