US Patent 6837912 Cyclone separator with surface vanes

A cyclone separator including vanes along the inside wall of the conical section of the separator to regulate the pitch and thus the axial velocity of the gas flow stream in the separator. By adjusting the pitch of the gas flow stream, the collection efficiency of the separator can be optimized so as to minimize the amount of dust particles which are re-entrained in the gas flow stream exiting the separator.