Paper fibres lifted from grading sieve by relative motion between grooved wing profile and sieve surface

摘要

A paper manufacturing process sieves fibres into two or more fractions under pressure. Fibres are lifted from the sieve (2) by a wing profile remover element (1). The profile (1) has a surface (3) directed to the sieve (2) with a series of transverse grooves (4). Relative motion of the element (1) and the surrounding suspended fibres creates moving micro-vortices (5). Relative motion of the profiles (1) and the surrounding suspended fibres creates moving micro-vortices (5). The vortices promote hydraulic exchange between the sieve surface (6) and profile (1). The vortex axis of rotation (9) is parallel to the sieve surface (6) and perpendicular to the profile (1) direction of travel (10). The grooves (4) are pref. 2-5 mm deep (b) and no less than the gap between the profile (1) surface and sieve surface (6). Grooves are pref. 2-10 mm wide (a) in the direction of travel (10). The sieve round apertures (8) are 1.5-10 mm in diameter.