In order to meet clients' requirements for different fineness, Longyi R&D team developed the new upgraded classifier to classifying powder. It adopts direct-connected motor style impeller classifying system technology, also could collocates with electronic frequency converter to achieve step less speed adjustment to suitable for classifying different fineness powder, after that to realize high degree automation. Longyi air classifier with a compact structure could save space, even could match with different kinds grinding mills flexibly such as (grinding roller mills, ball mills, Raymond mills) etc, and works in a closed circuit system.