FIELD: concentration of minerals; separation of fine fractions according to their sizes. SUBSTANCE: vortex flow of pulp is formed on inner surface of sieve in form of helical spiral made by compression spring located coaxially between upper and lower cylindrical parts of housing. Liquefied water is fed to circular clearance between helical spring and central tube through tangential branch pipe in form of ascending flow. Inter-turn gap of compressed helical spiral is adjusted by threaded device found in upper portion of housing; it is made in form of rod passed through central tube; said rod is provided with thread at upper end and with handwheel at other end. Vibration transmitted from vibrator through rocker arm, rod and upper part of housing are transformed to axial oscillations of helical spiral in form of compression and release of spring; deviations of size of its inter-turn gap and volume of outer circular passage between working spring and inner surface of outer engageable parts of housing form radial pulsating flow of pulp. Consumption of oversizes and undersizes is regulated by means of changeable attachments fitted on tangential branch pipes. EFFECT: enhanced efficiency; reduction of idling periods. 3 cl, 1 dwg
