ABSTRACT
Of the various types of mechanical defoaming devices, the most commonly used employ a rotary action. Such devices include rotating discs, various impeller arrangements, centrifugal baskets, spinning cones, and cyclones. However, other types of devices have also been investigated. These latter include ultrasonic devices (see, e.g., reference [7] and references cited therein), application of vacuum through a suitable membrane [1,9-11], use of packing materials of appropriate wettability (see Section 7.4), and even application of liquid sprays [1,10,12]. Here we review the use of most of these mechanical defoaming devices and include speculation concerning the mechanisms by which they function.
