Impact mill for fine grain grinding - has fine and coarse prod. separator, with coarse fraction recycling for repeated grinding

摘要

The mill with raw material feed (21) has an extract line (51,52) for the fraction which does not pass through the sieve (33). The extract line leads, pref. via a cyclone (53) with cell wheel discharge (55), onto a vibrating sieve (44). From this sieve the coarser material, not passing this sieve, is discharged at an overflow (45) to combine with the material entering (23) from the hopper (21), while the finer material leaves to enter the fine material collecting space (11) around the sieve. Preferably, the raw material from the hopper is fed into the inlet duct (23) from a vibrating tray (22), driven, together with the vibrating sieve (44), by a common drive (42).