Abstract: A tank with an upwardly concave bottom, a rotatable center shaft running on the vertical axis of the tank from the top of the tank to the bottom, middlings outlets at the side of the tank, a sands discharge outlet at the bottom of the tank, an overflow means connected at the side of the tank, a sand rake connected to the center shaft to rotate with the shaft and positioned to move settled sand toward the sand discharge outlet and a means for rotating the center shaft, the improvement which comprises a combination of two or more saucer-shaped deflecting baffles located in the cell and concentric with the shaft and affixed thereto, the lowest baffle being located immediately above the sand rake, and inverted to the bottom of the cell and having a skirt extending downward from the outer periphery thereof and at least one other deflecting baffle being located in between the feed well and the lower baffle.