Centrifugal flotation separator

A multi-stage, recycling, centrifugal, flotation separator system, comprising a circular cylindrical vessel with vertical axis, having a horizontal tray positioned inside the vessel near the top, the tray having an axial opening. Means for introducing air under pressure into the vessel at the top thereof, and means for introducing contaminated liquid into the vessel through a tangential pipe, under pressure, at a level below the tray. Means to recycle air from the top of the vessel into the inlet line and to mix the recycled air with the contaminated liquid before entry into the vessel. Means to recycle liquid from the bottom of said vessel, through a tangential pipe into the vessel at a level below that of the contaminated liquid, and means to mix recycled air with the recycled liquid prior to entry into the vessel.