Method and apparatus for conveying and metering solid material

Abstract

A solid material pump or conveyance apparatus and method including a pump housing an inlet and an outlet with a passageway between them. The passageway is formed and defined by a friction drive wall which is movable relative the pump housing towards the outlet and a wall stationary relative the pump housing. The friction drive wall has a greater surface area for contacting the solid material than the stationary wall. The friction drive wall exerts frictional forces upon the solids material introduced through the housing inlet which exceed the frictional drag exerted upon the material by the stationary wall, so that the net frictional force drives the material in a forward direction toward the housing outlet. The solid material is compacted or compressed prior to or upon entry into the pumping apparatus to a sufficient level so that the solid material exhibits some of the properties of a liquid. Due to the semi-hydrostatic behavior of the solid material, the frictional forces exerted by the drive wall conveys the entire mass of material through the passageway. This provides a convenient method and apparatus for conveying solid materials which is non-jamming. Additionally, since there is little or no slippage between the friction drive wall and the semi-hydrostatic solid mass, the amount of solid material flowing through the passageway may be metered according to conventional techniques.