Patents by Inventor Septimus H. C. Liang

Septimus H. C. Liang 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: 5462908
    Abstract: A novel organic amine-impregnated activated carbon composition is disclosed which may be used in breathing gas filters to enhance removal of various toxic perfluorocarbons. Three processes for impregnating activated carbon with organic amines are also disclosed. One of these processes comprises the steps of placing the amine in contact with substantially dry activated carbon, subjecting the carbon and amine to an environment devoid of oxidizing gases or vapors (such as oxygen gas), and then heating the carbon and amine for an extended period while maintaining this oxidizer-free environment. Pretreatment procedures to enhance both the shelf-life and service-life of the amine-impregnated activated carbon are also disclosed.
    Type: Grant
    Filed: June 16, 1993
    Date of Patent: October 31, 1995
    Assignee: Her Majesty the Queen in right of Canada, as represented by the Minister of National Defence
    Inventors: Septimus H.-C. Liang, Brian H. Harrison, Jack Pagotto
  • Patent number: 5192735
    Abstract: Activated charcoal, or ASC whetlerite charcoal for use in providing protection against chemical warfare agents, contains chromium VI, which is a known carcinogen, as well as other metal impregnants. Thus disposal of the charcoal can present problems. The charcoal is usually impregnated with the chromium and other active metals by placing the charcoal in a solution of the metals, and oven drying the charcoal so that crystals are deposited thereon. It has been found that if the charcoal is freeze-dried the quantity of the metals such as chromium VI can be reduced by as much as 50% without compromising the performance of the charcoal.
    Type: Grant
    Filed: February 20, 1992
    Date of Patent: March 9, 1993
    Assignee: Minister of National Defence of Her Majesty's Canadian Government
    Inventors: Jack G. Pagotto, Septimus H. C. Liang