FIELD: chemistry.
SUBSTANCE: invention relates to separation of disperse loose medium, of different size, and can be applied to agriculture for removal of foreign impurities when cleaning cereals (as wheat, rye, barley, etc.) from finely dispersed medium (dust), and also to chemical industry, construction industry, and other industries, for separation of loose materials. Method for removing small particles from coarse layer of loose materials comprises feeding material, separation of impurities during bottom to top purging by vertical air flow with formation of high and low-speed air blowing zones, and discharge of removed fractions along direction of air flow. Material is fed in amount sufficient for formation of dense fixed layer, which then is blown with air flow of rate close to speed for beginning of boundary grain fluidisation in removed impurities, with formation of fluidised bed. High speed blowing air zone is created using hollow cylinder submerged into formed fluidised bed, whereupon discharge and transportation of removed particles is performed.
EFFECT: technical result is increase of uniformity and improved quality of separation of disperse loose materials by size, without additional costs for discharge and transportation of fine particles.