TY JOUR TI PNEUMATIC SEPARATOR FOR FRACTIONAL SEPARATION AND GRAIN CLEANING KW pneumatic separator KW separation zone KW grain material KW light fraction KW heavy fraction KW air flow KW pneumatic separation channel JO Vestnik of Omsk SAU AU KOROSTELEV, D.N. AU CHERNYAKOV, A.V. AU KOVAL, V.S. PY 2024 IS 55 PB FSBEI HE Omsk SAU