Patent ID: 7267049

Claim:
A screw press ( 1 ) for pressing fibrous material or sugar beet pulp, comprising: a feeding end and a discharge end, said fibrous material being urged during pressing according to a material advancement direction from said feeding end to said discharge end; at least one pair of helical elements ( 20 , 30 ) disposed mutually parallel and side by side, each of said helical elements ( 20 , 30 ) comprising at least one helix ( 22 , 23 , 32 , 33 ) disposed about a rotary shaft ( 21 , 31 ) which extends along a predetermined axial direction (X-X, X′-X′); a perforated walled filtering cage ( 5 ) supported by a series of equidistant hoops ( 13 , 14 ) and enclosing said pair of helical elements ( 20 , 30 ) as an exact fit; for feeding the fibrous material to the press, a loading hopper ( 8 ) fixed to the hoops ( 13 , 14 ) supporting the cage ( 5 ); for exit of the pressed fibrous material, a discharge opening ( 9 ) positioned in proximity to said discharge end of the press ( 1 ) with respect to said material advancement direction; a collection sump ( 10 ) positioned externally to said filtering cage ( 5 ), to collect a liquid component of the pressed fibrous material; characterised in that said filtering cage ( 5 ) having an upper part and a lower part, said upper part is supported by upper hoops of said series of equidistant hoops and said lower part is supported by lower hoops of said series of equidistant hoops ( 13 , 14 ), the upper part being of modular structure having a plurality of modules, a distance between axes of each module (M) of said plurality of modules is constant and is a sub-multiple of, or equal to, a dimension of the loading hopper ( 8 ) measured along said predetermined axial direction, each of said plurality of modules (M) comprising at least two of said upper hoops ( 13 ), said loading hopper ( 8 ) being shiftable to a place that was occupied by one or more of said plurality of modules (M) in which one or more of the modules replaced a place that was occupied by the loading hopper before it was shifted.