Patent ID: 6910585

Claim:
A dynamic centrifugal gas classifier comprising: an annular-shaped inner passage having a horizontal axis; an annular-shaped outer passage circumscribing at least a portion of the inner passage; first inlet means for introducing a gas-entrained particulate material substantially tangentially into the inner passage so as to impart a centrifugal force to the particulate material; second inlet means for introducing a gas into the outer passage; means for separating finer and coarser fractions of the particulate material by passing the gas flowing in the outer passage through at least a portion of the particulate material; means for returning the finer fraction to the inner passage; vertical outlet means for receiving the coarser fraction from the separating means and removing the coarser fraction from the dynamic centrifugal gas classifier; horizontal outlet means for removing the finer fraction from the inner passage, the horizontal outlet means being disposed at the horizontal axis of the inner passage and surrounded by the inner passage; and rotating means having a horizontal axis of rotation and disposed in the horizontal outlet means for applying additional centrifugal force to the finer fraction to prevent an intermediate fraction of the particulate material from entering the horizontal outlet means.