Abstract: 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.

Abstract: A screw press (1) for pressing fibrous material, in particular sugar beet pulp, comprising: at least one pair of helical elements (30) which are disposed mutually parallel and side by side and comprise at least one helix (32, 33) disposed about a rotary shaft which extends along a predetermined axial direction; a perforated walled filtering cage (5) supported by equidistant hoops (13, 14) and enclosing the helical elements (30) as an exact fit; a loading hopper (8); a discharge opening (9) for the exit of the pressed material; a collection sump (10) positioned externally to the filtering cage (4); in which the filtering cage (5) presents a modular structure having a distance between the axes of each module (M) which is constant and is a sub-multiple of, or equal to, the dimension of the loading hopper (8) measured along the predetermined axial direction, the loading hopper (8) being shiftable by its replacing one or more modules (M) of the filtering cage (5).