Patent attributes
A screw press for pressing fibrous material, in particular sugar beet pulp, having a pair of adjacent counter-rotating shafts parallel axes, the shafts each having a helical structure winding in the opposite direction to the helical structure of the other shaft, a perforated filtering cage enclosing said helical structures, a loading hopper for feeding the fibrous material to the press, a discharge aperture for the exit of the pressed material, the helical structures having a helix (22, 32) and a helical element (23, 33), which has at least one perforated surface and a helical interspace with the outer surface of the shaft, the perforated surface having a length (L) along the axis of the shaft which is less than the pitch (P) of the helix so as to receive the helix of the adjacent shaft.