Patents by Inventor Naresh K. Rohatgi

Naresh K. Rohatgi 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: 4846224
    Abstract: Fluidics flow control of a multiphase supply using a cylindrical chamber is achieved by introducing the supply flow radially into the chamber. The supply flow exits through a port in the center at the chamber. A control fluid is then introduced tangentially about 90.degree. upstream from the supply port. A second control fluid port may be added about 90.degree. upstream from the first control fluid port, but preferably two sets of supply and control ports are added with like ports diametrically opposite each other. The control fluid flows against the circular wall of the control chamber, which introduces a vortex in the flow of the supply flow that decays into a spiral path to the exit port in the center of the chamber. The control flow rate may thus be used to control the spiral path, and therefore the supply flow rate through the exit port.
    Type: Grant
    Filed: August 4, 1988
    Date of Patent: July 11, 1989
    Assignee: California Institute of Technology
    Inventors: Earl R. Collins, Jr., Wilbur J. Marner, Naresh K. Rohatgi
  • Patent number: 4664944
    Abstract: An improved deposition method for producing silicon carbide high-temperature semiconductor material comprising placing a semiconductor substrate composed of silicon carbide in a fluidized bed silicon carbide deposition reactor, fluidizing the bed particles by hydrogen gas in a mildly bubbling mode through a gas distributor and heating the substrate at temperatures around 1200.degree.-1500.degree. C. thereby depositing a layer of silicon carbide on the semiconductor substrate.
    Type: Grant
    Filed: January 31, 1986
    Date of Patent: May 12, 1987
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventors: George C. Hsu, Naresh K. Rohatgi
  • Patent number: 4391609
    Abstract: A method of desulfurization is described in which high sulfur coals are desulfurized by low temperature chlorinolysis (12) of coal in liquid media, preferably water, followed by hydrodesulfurization (26) at a temperature above 500.degree. C. The coals are desulfurized to an extent of up to 90% by weight and simultaneously dechlorinated to a chlorine content below 0.1% by weight. The product coals have lower volatiles loss, lower oxygen and nitrogen content and higher fixed carbon than raw coals treated with hydrogen under the same conditions.Heating the chlorinated coal to a temperature above 500.degree. C. in inert gas such as nitrogen results in significantly less desulfurization.
    Type: Grant
    Filed: October 30, 1981
    Date of Patent: July 5, 1983
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: John J. Kalvinskas, Naresh K. Rohatgi
  • Patent number: 4325707
    Abstract: A method of desulfurizing coal is described in which chlorine gas is bubbled through an aqueous slurry of coal at low temperature below 130 degrees C., and at ambient pressure. Chlorinolysis converts both inorganic and organic sulfur components of coal into water soluble compounds which enter the aqueous suspending media. The media is separated after chlorinolysis and the coal dechlorinated at a temperature of from 300 degrees C. to 500 degrees C. to form a non-caking, low-sulfur coal product.
    Type: Grant
    Filed: May 12, 1980
    Date of Patent: April 20, 1982
    Assignee: California Institute of Technology
    Inventors: John J. Kalvinskas, Nick Vasilakos, William H. Corcoran, Karel Grohmann, Naresh K. Rohatgi