Dispersing or emulsifying apparatus

In such an apparatus wherein a rotor (1) sucks in liquid axially and flings it out radially through slots (5) formed in a stator ring (2), so subjecting the particles in the liquid to substantial shearing and resultant comminution, the width of the slots (5) of the stator (2) or slots (4) formed in the rotor (1) is adjustable. In the embodiments, shown, a ring (9), rotatable with respect to the stator (2), has teeth (11) which can cover the stator slots (5) to a greater or lesser degree. Ring (9) may be rotated by means of knob (15) acting via an eccentric (14) on a projection (13) on ring (9) (Fig. 5).