Patents by Inventor Tapani Niiranen

Tapani Niiranen 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: 4995991
    Abstract: A disc filter and method of operating same is provided in which a liquid jet is intermittently used to detach pulp cake from the disc filter. In operation, mechanical or electrical means actuate a nozzle to spray pressurized fluid at a portion of the boundary between the surface of each disc filter segment and its associated pulp cake. The nozzle is actuated to begin spraying as respective segments move into register with the nozzle and are cause to discontinue spraying prior to moving out of register when the loosened pulp cake falls from the segments by gravity. the improved control of pulp cake removal reduces use of washing fluid and results in improved pulp cake consistency.
    Type: Grant
    Filed: March 21, 1989
    Date of Patent: February 26, 1991
    Assignee: Ahlstrom Corporation
    Inventors: Risto Ljokkoi, Tapani Niiranen, Pekka Purho, Erkki Savolainen, Jari Siitonen
  • Patent number: 4678574
    Abstract: A method for improving the operation of a disc filter used for the filtering of fluids containing solid matter such as fibers. Known filtering methods have the drawback that the rate of water exhaustion is limited, because a vacuum tends to be created inside the sectors when the filtered fluid is drained by suction from the central channel of the disc filter. This drawback is an obstacle to increasing the speed of rotation and therefore to increasing the capacity of the disc filter. With the method of the present invention, this problem is solved by providing the disc filter with a means of admitting ambient air into the disc sectors and the central shaft channel and/or with equipment for blowing air into the sectors and the channel to remove the filtered fluid from them.
    Type: Grant
    Filed: December 3, 1985
    Date of Patent: July 7, 1987
    Assignee: Enzo-Gutzeit OY
    Inventors: Tapani Niiranen, Erkki Savolainen, Raimo Kohonen