Patent attributes
A frustro-conical chamber for separating particles in a fluidized bed for blood component or cell separation. The chamber is characterized by an injection-directing surface for directing inflowing fluid along a frustro-conical wall of the chamber. A dam adjacent the cell-injection port may be circumferentially disposed within the chamber and may have its maximum height adjacent an injection port, and the height may diminish away from the injection port. The injection directing surface may comprise a shelf extending into the interior of the chamber from the injection port, thereby impeding fluid flow in the direction of an outlet port.