Patents by Inventor Jean-Mathieu de Rigaud

Jean-Mathieu de Rigaud 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).

  • Publication number: 20020148581
    Abstract: Processes for manufacturing a paper product from cellulose pulp, part of which comes from a broke and part of which comes from a fresh pulp are provided. The processes involve first redissolving in a broke pulper, with stirring and in an alkaline medium, cellulose fibers contained in said broke to form a broke pulp. Next, the broke pulp is brought to a concentration and a pH close to that characteristic of the fresh pulp by (1) diluting said broke pulp with a white water and (2) acidifying said broke pulp by injecting carbon dioxide into said broke pulp after the broke pulp has left the broke pulper and before admixing said broke pulp with said fresh pulp. Then the broke pulp is admixed with the fresh pulp to form a pulp mixture and the pulp mixture is dewatered to form a paper product and a white water.
    Type: Application
    Filed: June 17, 2002
    Publication date: October 17, 2002
    Inventors: Jean-Mathieu De Rigaud, Alain Sauvage
  • Patent number: 6287471
    Abstract: The present invention relates to a process for treating more or less concentrated aqueous effluents, such as processing waters, industrial or urban waste waters, and sludges, in particular sludges derived from these waste waters. The said process comprises at least one step of physical separation of a liquid phase and of a solid phase dispersed in the said liquid phase and at least one addition of chemical conditioning reagents and optionally of antifoaming agents. The process also comprises the injection of carbon dioxide (CO2) into the said aqueous effluents, in an amount which is sufficient to give them a pH of less than 7.8.
    Type: Grant
    Filed: September 7, 1999
    Date of Patent: September 11, 2001
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventor: Jean-Mathieu De Rigaud
  • Patent number: 6207062
    Abstract: The present invention relates to a process for treating more or less concentrated aqueous effluents, such as processing waters, industrial or urban waste waters, and sludges, in particular sludges derived from these waste waters. The said process comprises at least one step of physical separation of a liquid phase and of a solid phase dispersed in the said liquid phase and at least one addition of chemical conditioning reagents and optionally of antifoaming agents. The process also comprises the injection of carbon dioxide (CO2) into the said treated aqueous effluents, in an amount which is sufficient to give them a pH of less than 7.8.
    Type: Grant
    Filed: March 8, 1999
    Date of Patent: March 27, 2001
    Assignee: L'Air Liquide, Societe Anonyme pour l'Etude et l'Exploitation des Procedes Georges Claude
    Inventor: Jean-Mathieu de Rigaud