Sulzer offers a range of coalescers designed to accelerate the separation of either primary or secondary immiscible liquid dispersions. Today, coalescers are often considered preferable to conventional gravity separators.

Drops of liquids in blue light
The simplest forms of equipment used to separate dispersions are horizontal or vertical settling tanks. The capacity of such vessels will decrease when the rate of coalescence and separation decreases. This may lead to uneconomic vessel dimensions for some applications, and methods to improve the separation kinetics have to be applied. These can be directed to increasing the driving force or towards accelerating the steps of the basic coalescence mechanism.