3. Agitation of liquid-solid systems

3.1 Issues

Liquid-solid systems are frequently encountered in the mineral, chemical and pharmaceutical industries. The objectives vary widely, from dissolution, crystallization, catalyzed chemical reaction... to suspension. Transfer phenomena can be limiting, whether between the solid particle and the liquid, or between the suspension and the wall.

Depending on the application, the requirements in terms of solid distribution in the tank differ, and several degrees of suspension can be distinguished (figure 5 ). Complete suspension exists when all particles are in motion in the tank, and no particle remains at the bottom of the tank for more than 1 to 2 sec. Under these conditions, the...