EP0804964B1 EP97114161A EP97114161A EP0804964B1 EP 0804964 B1 EP0804964 B1 EP 0804964B1 EP 97114161 A EP97114161 A EP 97114161A EP 97114161 A EP97114161 A EP 97114161A EP 0804964 B1 EP0804964 B1 EP 0804964B1 Authority EP European Patent Office Prior art keywords accordance classifier vanes housing mill …