Patents by Inventor Pieter C. Veenstra

Pieter C. Veenstra 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).

  • Apparatus for exchange of substances between two media on opposite sides of a membrane
    Patent number: 3977976
    Abstract: An apparatus for exchanging substances through a membrane which is permeable thereto has a drum or the like rotatably disposed in a housing, a membrane in spaced relation with the housing and drum about the drum, inlet means for introducing a liquid containing a substance which is to be replaced with another substance and a discharge means spaced from the inlet means to cause tangential flow of the liquid between the drum and membrane, and means for introducing fresh fluid into the housing.
    Type: Grant
    Filed: August 5, 1974
    Date of Patent: August 31, 1976
    Inventors: Josef A. E. Spaan, Pieter C. Veenstra, Johannes M. M. Oomens