Blending is an important operation in process industries. Under turbulent conditions, it occurs via convection and turbulent dispersion. In the present work, attempts have been made to identify the controlling mechanism, by comparing the blending performance of three different equipments: stirred tanks, jet mixers and ultrasound mixers. It is seen that jet mixers offer lower mixing time as compared with impeller mixers, whereas ultrasonic horns show higher mixing time as compared with impeller mixers, when compared at the same level of power consumption in tanks having the same size. (C) 2003 Elsevier Science Ltd. All rights reserved.