Angle-head centrifuge

In the rotor of an angle-head centrifuge, tubes are held in a fixed position at angles from 25° to 40° to the vertical axis of rotation. Upon centrifugation, particles are driven outward horizontally but strike the side of the tube so that the sediment packs against the side and bottom of the tube with the surface of the sediment parallel to the shaft of the centrifuge. As the rotor slows down and then stops, gravity causes the sediment to slide down the tube usually a poorly packed pellet is formed. 

Leakage from a tube in an angle-head centrifuge rotor resulting from overfilling a tube and placing aslant in the rotor. 

Figure 9-1. Cross-sectional diagram of an angle head rotor showing the distances from the axis of rotation to the top, middle, and bottom of the centrifuge tube. (Courtesy Spinco Division, Beckman Instruments, Inc., Palo Alto, Calif.)...

Montmorillonite, especially the sodium form in low-ionic strength solutions, swells consequently, centrifugation in moderately high fields is needed to separate the clay particles and the solutions. Clay suspensions were usually centrifuged with a DuPont Sorvall RC-5 refrigerated super-speed centrifuge with an angle-head... 

It is supplied with a dual purpose head. The buckets can either swing out to the horizontal position or, by means of a rubber adapter, the buckets can be held at a fixed angle of 45° (M.S.E.) or 51° (International) in the latter case, the instrument acts as an angle centrifuge. This is an alternative to the hand centrifuge. 

If detachment of the particles takes place as a result of forces directed at an angle to the dust-laden surface, then the original substrate is placed at the appropriate angle in the sockets of the centrifuge, or else a holder (Fig. II.8) with a rotating head for the plate is employed. 

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