An apparatus (10) for removing particulates from a fluid is described. The apparatus (10) includes a rotatable vessel (12) for receiving a dirty fluid containing the particulates in suspension, the vessel (12) having a plurality of side walls (14) arranged to form a polygonal cross-sectional shape in a plane orthogonal to an axis of rotation of the vessel. The vessel (12) has a fluid inlet port (16) through which the dirty fluid enters the vessel, and a fluid outlet port (18) through which a clean fluid exits the vessel after removal of particulates. The apparatus (10) also comprises a solids discharge port (20) provided at each of the vertices of the polygonal cross-section wherein, in use, when the vessel is rotated the particulates in the fluid entering the vessel (10) migrate to the vertices, from where they can be discharged through the discharge ports.

A blood washing system including a rotor defining an internal chamber and a skimmer assembly configured to move a withdrawal needle within the internal chamber. A multi-component fluid, such as a whole blood sample, can be fed into the internal chamber via a feed tube, where the rotor can be rotated to fractionate the multi-component fluid. A brake can be applied to the rotor to cease rotation or rotated at a slower speed to allow the fractions of the multi-component to settle on a bottom wall of the rotor. The withdrawal needle is moveable within the internal chamber to align an orifice of the withdrawal needle for withdrawing the liquid fractions and isolate the solid fractions. Wash fluids can be added to the internal chamber to repeat the wash cycle without removing the solid fractions. The washed solid fractions can be withdrawn via the feed tube and collected.

A blood washing system including a rotor defining an internal chamber and a skimmer assembly configured to move a withdrawal needle within the internal chamber. A multi-component fluid, such as a whole blood sample, can be fed into the internal chamber via a feed tube, where the rotor can be rotated to fractionate the multi-component fluid. A brake can be applied to the rotor to cease rotation or rotated at a slower speed to allow the fractions of the multi-component to settle on a bottom wall of the rotor. The withdrawal needle is moveable within the internal chamber to align an orifice of the withdrawal needle for withdrawing the liquid fractions and isolate the solid fractions. Wash fluids can be added to the internal chamber to repeat the wash cycle without removing the solid fractions. The washed solid fractions can be withdrawn via the feed tube and collected.

A self-emptying separator includes an emptying mechanism, having a piston valve, which is designed to intermittently open and close the solid emptying openings of the separator. A control arrangement for the emptying mechanism includes a chamber for a fluid and a valve arrangement having at least one valve in communication with the chamber in order to operate the piston valve. As the fluid, the product to be clarified can be fed from a distributor or the separation chamber of the centrifugal drum via a supply channel in the drum to the chamber. The valve is a centrifugal force valve, which closes against a spring force by centrifugal force at the operating speed of the centrifugal drum and is opened by this spring force at a lower speed of the centrifugal drum than the operating speed, or the valve is an electromagnetically actuable valve.

A self-emptying separator includes an emptying mechanism, having a piston valve, which is designed to intermittently open and close the solid emptying openings of the separator. A control arrangement for the emptying mechanism includes a chamber for a fluid and a valve arrangement having at least one valve in communication with the chamber in order to operate the piston valve. As the fluid, the product to be clarified can be fed from a distributor or the separation chamber of the centrifugal drum via a supply channel in the drum to the chamber. The valve is a centrifugal force valve, which closes against a spring force by centrifugal force at the operating speed of the centrifugal drum and is opened by this spring force at a lower speed of the centrifugal drum than the operating speed, or the valve is an electromagnetically actuable valve.