Patents by Inventor David G. Ritchie

David G. Ritchie 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).

  • Photocatalytic fluid purification apparatus having helical nontransparent substrate
    Patent number: 5069885
    Abstract: Apparatus for the purification of a fluid, such as water, which in the presence of light of an activating wavelength brings the fluid into contact with surfaces with fixed photoreactive coatings of anatase (TiO.sub.2) or other photoreactive semiconductors, thereby detoxifying, reducing or removing organic pollutants therefrom. The apparatus includes a nontransparent substrate coiled longitudinally and helically around a transparent sleeve. The nontransparent substrate has photoreactive semiconductor material bonded thereto. The nontransparent substrate defines a helical path through an annular cylindrical housing.
    Type: Grant
    Filed: April 23, 1990
    Date of Patent: December 3, 1991
    Inventor: David G. Ritchie