Method for a continuous dry milling operation of a vertical grinding mill and vertical grinding mill

A vertical grinding mill comprising

• a vertical, closed milling container (1);
• a screw conveyor (2) which is arranged centrally in the milling container (1), the screw conveyor (2) comprising
• a drive shaft (4) with a central axis (3) and
• at least one screw flight (5) which is arranged on the drive shaft (4), extends along a height (hs) up to an upper end (6) and covers the cross-section of the milling container (1) only partially;
• a package of grinding bodies (17), the package having an upper surface (39);
• a grinding stock inlet (19) which projects into the milling container (1) above the package of grinding bodies (17);
• a gas inlet (24, 24′, 24″) which projects into the milling container (1) for introducing gas;
• a grinding stock outlet (11) which projects out of the milling container (1) and has a lower edge (18) and a height (h13) for discharging grinding stock (22) and gas;
• and
• a motor (7) for driving the screw conveyor (2) in a direction of rotation (8) where the at least one screw flight (5) conveys grinding bodies (17) upwards, wherein
• the grinding stock outlet (11) comprises an outlet opening (13) with a screen (14);
• the upper end (6) of the at least one screw flight (5) is arranged on a level with the screen (14);
• and
• the gas inlet (24, 24′, 24″) is arranged above the upper end (6) of the at least one screw flight (5).