Patents by Inventor Leif U. F. Thorsell

Leif U. F. Thorsell 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 preparing cellulose pulp from lignocellulosic material while removing high molecular weight substances from the pulping liquor
    Patent number: 4670098
    Abstract: A process is provided for preparing cellulose pulp by delignification of lignocellulosic material, which comprises subjecting particulate lignocellulosic material in a pulping zone to the pulping action of a pulping liquor at a temperature at which pulping reactions leading to formation of cellulose pulp proceed, and substances having a molecular weight above about 3500, preferably above about 2000, and preferably above about 1500, are physically separated and removed from the lignocellulosic material and become dispersed in the pulping liquor; in the course of the pulping, withdrawing pulping liquor containing such dispersed substances, and removing such dispersed substances therefrom; and then returning the pulping liquor to the pulping zone.
    Type: Grant
    Filed: December 23, 1985
    Date of Patent: June 2, 1987
    Assignee: Mo och Domsjo AB
    Inventors: Leif U. F. Thorsell, Nils O. Nilsson