SCREW CONVEYOR COMPRISING TWO CONCENTRIC SHAFTLESS SCREWS

摘要

A conveyor comprising a pipe and a first screw (10) which is arranged inside and essentially conentrically with the pipe and which is rotatable relative to the pipe and comprises at least on vane (11) which in the radial direction extends between a first inner radius and a first outer radius and which describes a first helix on a first geometric cylinder with said first inner radius. Moreover, the conveyor comprises a second screw (20) which is arranged essentially concentrically with said pipe (30) and said first screw (10). The second secrew (20) is arranged inside said first geometric cylinder and is rotatable relative to the first screw (10).