ISM-eto bezreshetny pneumatic separators of new generation which in the basis have impeller — the impeller machine concluded in ring. Such design allows to lower significantly air overflowing on the ends of blades and by that to reduce losses of power on inductive resistance. Besides, the ring allows to reduce some noisiness of air krylchatka, unlike separators of similar type where radial . fans are used; Specialists of our company have come To such design decision as a result of long-term researches of the aerodynamic processes influencing grain calibration. The powerful contribution to creation of separators was made also by the staff of the Kharkov aviation institute.