Patent ID: 6845867

Claim:
A classifier for the classification of granular material comprising: a classifier housing having a V-shape in vertical section with first and second legs and including a stairway cascade in said first leg, said stairway cascade lying obliquely at an angle departing from the vertical and said stairway cascade being permeable for passage for classifying gas there through, a classifying gas intake duct in said first leg directing classifying gas to said stairway cascade including a louver partition in upstream relation to said stairway cascade, and classifying flues lying one above the other and obliquely downwardly inclined in louver fashion in said second leg, said classifying flues defining classifying ducts there between and being positioned to define a classifying zone between said stairway cascade and said classifying flues, a feed inlet opening for a classification feed on the top of said housing and above said classifying zone, an oversize fraction discharge opening on the bottom of said housing below said classifying zone for the discharge of an oversize fraction of said granular material and upwardly extending guide vanes at the upper end of said classifying flues, said guide vanes being adjustable to control the velocity of said classifying gas passing through said classifying ducts.