Patents by Inventor Junchang Dong

Junchang Dong 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: 5516492
    Abstract: In a reactor and process for the photopromoted catalytic decomposition of compounds in a fluid stream, the area of a catalyst support structure and/or the amount of catalyst on the support structure is varied as a function of distance from a light source to enhance quantum efficiency. In a preferred embodiment, the support structure has a surface area per unit of reaction chamber volume which increases with distance from the light source, or the amount of catalyst on the support structure per unit area increases with distance from the light source to maintain the light intensity on the catalyst within a desired range regardless of dispersion and/or absorption effects. In another embodiment, the support structure includes a plurality of curved plates which may, for example, be spherical, cylindrical or helical.
    Type: Grant
    Filed: June 30, 1992
    Date of Patent: May 14, 1996
    Assignee: ClearFlow Inc.
    Inventors: Junchang Dong, Elliot Berman
  • Patent number: 5189917
    Abstract: A device for monitoring pressure variations for mercury manometers including; a manometer tube with a column of mercury; at least two taps in the tube with one tap in the mercury column and the other above the column; a power supply interconnected between the taps; a resistance element extending between the taps in the mercury; and means for sensing the output voltage across the taps representative of the variations in the shunting effect on the resistance element of the mercury column as it rises and falls with pressure.
    Type: Grant
    Filed: July 22, 1991
    Date of Patent: March 2, 1993
    Assignee: Trustees of Boston University
    Inventors: Kallambella M. Vijayakumar, Junchang Dong
  • Patent number: 5137703
    Abstract: The present invention provides a variety of thermal catalytic methods for the conversion of NO and other NO.sub.x compounds into environmentally compatible products such as molecular nitrogen, molecular oxygen, and carbon dioxide. The catalysts employed are able to remove NO in substantial percentage quantities over a wide temperature range of 0.degree.-1,000.degree. C. and a preferred temperature of 100.degree.-800.degree. C. both in the presence or in the absence of chemical reducing agents.
    Type: Grant
    Filed: September 27, 1990
    Date of Patent: August 11, 1992
    Assignee: Trustees of Boston University
    Inventors: Norman N. Lichtin, Kallambella M. Vijayakumar, Junchang Dong
  • Patent number: 4980040
    Abstract: A method is provided for the photopromoted solid-catalyzed decomposition of oxides of nitrogen such as nitric oxide which are major pollutants of air and the environment at large. By this method, oxides of nitrogen are decomposed into molecular nitrogen and molecular oxygen by reactive passage over a solid metal oxide catalyst at an elevated temperature under irradiation at wavelengths absorbable by the catalyst. In this manner, the major oxides of nitrogen pollutants originating in the exhaust gases produced by automobile engines, jet engines used in the propulsion of aircraft, gas-turbine power generators, and the combustion of fossil fuels generally are controlled and eliminated.
    Type: Grant
    Filed: June 26, 1989
    Date of Patent: December 25, 1990
    Assignee: Trustees of Boston University
    Inventors: Norman N. Lichtin, Kallambella M. Vijayakumar, Junchang Dong
  • Patent number: 4938855
    Abstract: A photopromoted catalytic method of producing ammonia by the reduction of molecular nitrogen is provided using a solid metal oxide catalyst and molecular hydrogen as the reducing agent. Pure gaseous nitrogen can be reduced by gaseous hydrogen in the absence of water using a photopromoted reaction which uses solar and/or artificial photoenergy.
    Type: Grant
    Filed: February 27, 1989
    Date of Patent: July 3, 1990
    Assignee: Boston University
    Inventors: Norman N. Lichtin, Junchang Dong