METHOD OF PORTION SCREENING OF AGGREGATED POWDER-LIKE MATERIALS AND DEVICE FOR REALIZATION OF THIS METHOD Russian patent published in 2005 - IPC

FIELD: screening powder-like materials for freeing them from agglomerates.

SUBSTANCE: proposed method includes cyclic feed of portions of powder to central part of sieve. Powder is distributed over entire surface of sieve for obtaining thickness δ_l=(2-4)d_ag, where d_ag is average size of agglomerates. Each cycle of portion screening is continued to breakage of all agglomerates and complete screening of powder at time reserve before delivery of next portion. Upon completion of screening, signal for loading the next portion is formed. Device proposed for realization of this method includes upper and lower boxes with sieve secured in between them and drive for imparting vibratory motion to them. Upper loading box is made in form of closed cylindrical shell which is provided with cover having central loading hatch. Located on sieve is rubbing member acting on entire area of sieve. Rubbing member is made in form of multi-beam structure with strips located between beams in parallel to tangents of circles of box shells at distance of (0.5-0.6)L from center of rubbing member, where L is length of beam; strips are located above plane of sieve creating clearance δ_l=(2-4)d_ag, where δ_l is thickness of layer for rubbing the agglomerate and d_ag is average size of agglomerates. Ratio of mass M of rubbing member to area of contact of all beams S with sieve cloth satisfies condition 2ς_m.p.≥M/S≥1.5ς_a, where ς_m.p. is strength of monoparticles of powder and ς_a is strength of agglomerates.

EFFECT: increased productivity; avoidance of impairment of proportioning in case of impaired looseness of powder.

5 cl, 3 dwg