Piston pump for use in gasifying fine grained and dust-like solids fuels

Abstract From the Canadian patent

Fine grained fuel such as coal dust is gasified at an elevated pressure by passing the fuel from a supply tank which is at atmospheric pressure by a pump into a pressure lock basin and therefrom into the gasifier, the fuel during such movement retaining its loose consistency. The pump in this case comprises an outer cylinder; a piston movable in said cylinder; and inlet opening for said fuel in the top of said cylinder; a hollow space in said piston for receiving said fuel, the said hollow space being open at the top and bottom, an opening in said top wall of the cylinder for receiving or releasing a gaseous medium under pressure; an outlet passage for said fuel in the bottom of said …