2-PHASE CLEANING FLOW DYNAMICS IN AIR INJECTED MILKLINES

The results of a study of slug flow dynamics in air injected milkline Clean-in-Place (CIP) systems are presented. Experimental measurements of slug velocity, slug length, and air admission rate made on 48, 73, and 98 mm ID milklines are presented. The air injector must be left op en long enough for the slug to travel the entire milkline in order to ensure contact between the slug and all pipe surfaces. Optimal mechani cal cleaning action is produced by slug velocities of 7 to 10 m/s. The rate of air admission through the air injector should be controlled t o produce superficial air velocity of 8 to 12 m/s to achieve these slu g velocities.