Air classifying process and air classifier
AssigneeChristian Pfeiffer
InventorErnst W. Hanke
Life of this patent
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Abstract
The invention relates to a process and to an air classifier for the separation of classifying material into coarse material and fine material. Known air classifiers suffer from considerable deficiencies with regards to the throughput and the separation efficiency. To avoid this, the invention provides for the performance of a separate reclassification, which takes place in the same way as the pre-classification, whilst incorporating mechanical centrifugal rejection of coarse material particles, particularly through the impact ledges of a centrifuge basket.
Claims11
Air classifier with at least one air classifier stage having a centrifuge basket drivable about a substantially vertical rotation axis and said stage having air ducts and radially outwardly positioned ledges through which ledges the classifying air from the air ducts flows from the outside to the inside of the basket, with a circular classifying chamber surrounding the centrifuge basket and a coaxial ring of guide vanes on the outside of the chamber, the classifying air being spirally introducable into the classifying chamber through the guide vanes, with a classifying material inlet above the classifying chamber and an outlet for the classified coarse material below the classifying chamber and with substantially coaxial suction removal for the fines-laden classifying air from the centrifuge basket,
- characterized in that said one air classifier stage (1), constructed as the upper, first air classifier stage (2) with a centrifuge basket (14) for the reclassification of the coarse material from the first air classifier stage, the centrifuge basket (14) of the second air classifier stage (2) having different dimensions to the centrifuge basket (9) of the upper first air classifier stage (1) and the second classifier stage comprises different vertically separated air ducts (18, 18', 19, 19') from which the classifying air is supplied to the second centrifuge basket.
Air classifier with at least one air classifier stage having a centrifuge basket drivable about a substantially vertical rotation axis and said stage having air ducts and radially outwardly positioned ledges through which classifying air from the air ducts flows from the outside to the inside of the basket, with a circular classifying chamber surrounding the centrifuge basket, a coaxial ring of guide vanes on the outside of the chamber, the classifying air passing through the guide vanes being spirally introducable into the classifying chamber, a classifying material inlet above the classifying chamber and an outlet for the classified coarse material below the classifying chamber and with substantially coaxial suction removal for the fines-laden classifying air from the centrifuge basket, characterized in that said one air classifier stage (1), constructed as the upper, first air classifier stage (1), is followed by at least one further, second air classifier stage (2) with a centrifuge basket (14) for the reclassification of the coarse material from the first air classifier stage, the centrifuge basket (14) of the second air classifier stage (2) having different dimensions to the centrifuge basket (9) of the upper, first air classifier stage (1), and said second air classifier stage comprising air ducts, which are constructed spirally with a tangential inflow direction for supplying classifying air to the second classifying chamber.
Dependencies are inferred from the claim text.