FIELD: ventilation systems. SUBSTANCE: plant for treatment of food stuff is closed in its form but one inlet and one outlet holes. Excess pressure required for circulation of processing air is created by air flow through inlet and outlet tunnels which are in communication with inlet and outlet holes. Tunnel has upper wall with injectors of opposite direction as compared with above-mentioned direction and lower wall provided with holes for evacuation of excessive air from tunnel created by air jets generated by fan injected by injectors. Method of reduction of air flow through inlet and outlet tunnels consists in directing many air jets from upper boundary surface of tunnel towards indicated direction and evacuating excessive air from tunnel created by air jets through holes in lower boundary surface of tunnel. EFFECT: enhanced efficiency. 7 cl, 6 dwg
