Abstract: Apparatus (10) and method to separate a loose mass formed by elements or materials (11) of different sizes, such as woody strands or wafers, comprising a separation chamber (13) into which the mass is inserted, a plurality of riddling rolls (16), mounted inside the chamber (13) rotating on axes of rotation parallel to each other and lying sybstantially on a same plane (X). Each of the riddling rolls (16) comprises a plurality of riddling elements (20), each of which is substantially square in shape, so as to form four cusps (22) in correspondence with the four tips of the square. The riddling elements (20) are adjacent to each other so that the cusps (22) form a plurality of grooves (24), and the riddling rolls (16) are axially staggered therebetween so that the cusps (22) of each roll (16) are constantly inserted, more or less deeply into the corresponding grooves (24) of the adjacent riddling roll (16), so as to define discharge apertures (25) with an alternated profile.

Abstract: Apparatus (10) and method to separate a loose mass formed by elements or materials (11) of different sizes, such as woody strands or wafers, comprising a separation chamber (13) into which the mass is inserted, a plurality of riddling rolls (16), mounted inside the chamber (13) rotating on axes of rotation parallel to each other and lying sybstantially on a same plane (X). Each of the riddling rolls (16) comprises a plurality of riddling elements (20), each of which is substantially square in shape, so as to form four cusps (22) in correspondence with the four tips of the square. The riddling elements (20) are adjacent to each other so that the cusps (22) form a plurality of grooves (24), and the riddling rolls (16) are axially staggered therebetween so that the cusps (22) of each roll (16) are constantly inserted, more or less deeply into the corresponding grooves (24) of the adjacent riddling roll (16), so as to define discharge apertures (25) with an alternated profile.

Abstract: Device incorporating rollers to separate particles of different gradings a plurality of adjacent rollers (11) forming a selection bed where each roller (11) has a surface conformation defining a plurality of circumferential peaks (12) alternating with circumferential grooves (13), the rollers (11) including at least a working position where the grooves (13) of one roller are facing and at least partly penetrated by the peaks (12) of the adjacent roller (11), the discharge gap (18) between the two adjacent rollers (11) having a substantially zig-zag development, in at least some rollers (11) the connection surface (26) between the peaks (12) and grooves (13), and/or the peaks (12) and/or the grooves (13) themselves being at least partly worked with protuberances, protrusions, hollows and/or facets (23, 24, 25).