Patents by Inventor Takatatsu Shimokawa

Takatatsu Shimokawa 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).

  • Process for concentrating aqueous urea solutions
    Patent number: 4316767
    Abstract: Disclosed is a process for concentrating aqueous urea solutions in which an aqueous urea solution is allowed to flow as a falling film in countercurrent contact with a stream of hot inert gas to concentrate it to 95-99% by weight and the aqueous urea solution so concentrated is then passed through a packed zone in cocurrent contact with a stream of hot inert gas to concentrate it to not less than 99.5% by weight.
    Type: Grant
    Filed: September 11, 1980
    Date of Patent: February 23, 1982
    Assignees: Toyo Enginnering Corporation, Mitsui Toatsu Chemicals Incorporated
    Inventors: Toyoyasu Saida, Takatatsu Shimokawa, Yuzuru Yanagisawa, Takashi Nagahama, Koji Ishida