Patents by Inventor Stephen Rudolf Alexander Zwart

Stephen Rudolf Alexander Zwart 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: 8283494
    Abstract: Process for the preparation of urea from ammonia and carbon dioxide in a urea production process comprising, in a high-pressure synthesis section: a. a reactor, wherein ammonia and carbon dioxide react to form a urea-comprising synthesis solution; b. a stripper, wherein the urea-comprising synthesis solution is heated and stripped, optionally in counter-current with a stripping agent; c. a submerged condenser, wherein the gas leaving the top of the stripper is, at least partially, condensed to form a condensate solution and d. an ejector, in the line connecting the submerged condenser and the reactor, supporting the transport of the condensate solution from the submerged condenser to the reactor, wherein a gas stream leaving the top of the submerged condenser is controlled by one or more controlling elements.
    Type: Grant
    Filed: December 3, 2007
    Date of Patent: October 9, 2012
    Assignee: Stamicarbon B.V.
    Inventors: Stephen Rudolf Alexander Zwart, Johannes Henricus Mennen
  • Publication number: 20100168473
    Abstract: Process for the preparation of urea from ammonia and carbon dioxide in a urea production process comprising, in a high-pressure synthesis section: a. a reactor, wherein ammonia and carbon dioxide react to form a urea-comprising synthesis solution; b. a stripper, wherein the urea-comprising synthesis solution is heated and stripped, optionally in counter-current with a stripping agent; c. a submerged condenser, wherein the gas leaving the top of the stripper is, at least partially, condensed to form a condensate solution and d. an ejector, in the line connecting the submerged condenser and the reactor, supporting the transport of the condensate solution from the submerged condenser to the reactor, wherein a gas stream leaving the top of the submerged condenser is controlled by one or more controlling elements.
    Type: Application
    Filed: December 3, 2007
    Publication date: July 1, 2010
    Inventors: Stephen Rudolf Alexander Zwart, Johannes Henricus Mennen