Patents Assigned to Philip D. Lindahl
  • Labyrinth seal coal injector
    Patent number: 5558473
    Abstract: The labyrinth seal coal injector is a safe, cost-effective means of continuously injecting dry, sized, coal and other mined materials into a pressurized hydraulic pipeline for transport. The injector consists of a rotor or screw rotated by a motor. Coal is compacted in the injector and forms a hydraulic seal against the pressure in the pipeline. A knife valve is used in initiation of the flow of coal into the pipeline.
    Type: Grant
    Filed: August 15, 1994
    Date of Patent: September 24, 1996
    Assignee: Philip D. Lindahl
    Inventor: Philip D. Lindahl