Patents by Inventor Robert Joel Hoffman

Robert Joel Hoffman 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).

  • Production of sodium sulfite
    Patent number: 4003985
    Abstract: Anhydrous sodium sulfite is made by a process involving introducing substantially anhydrous sodium carbonate concurrently with sulfur dioxide-containing gas into a saturated solution of sodium sulfite maintained at pH of between about 6.5 and about 7.6 at temperature above about 35.degree. C. to form a slurry of anhydrous sodium sulfite crystals, and withdrawing the crystals from the slurry. The process is initiated using a concentrated sodium sulfite solution containing less than about 3 ppm of dissolved iron.
    Type: Grant
    Filed: January 30, 1976
    Date of Patent: January 18, 1977
    Assignee: Allied Chemical Corporation
    Inventors: Robert Joel Hoffman, Samuel Louis Bean, Philip Seeling, James William Swaine, Jr.
  • Production of ammonium nitrate
    Patent number: 3987150
    Abstract: A process for the production of ammonium nitrate is provided wherein ammonium chloride is contacted with a gaseous stream containing nitrogen dioxide, in an inert liquid dispersing medium.
    Type: Grant
    Filed: November 20, 1975
    Date of Patent: October 19, 1976
    Assignee: Allied Chemical Corporation
    Inventors: Lawrence Peabody Gould, deceased, Robert Joel Hoffman