ABSTRACT
Chapter 1 discussed two major types of separation processes, component and phase separation. In component separation, the components are separated from a single phase by mass transfer. An example is gas absorption where one or more components are removed from a gas by dissolving in a solvent. In phase separation, two or more phases can be separated because a force acting on one phase differs from a force acting on another phase or because one of the phases impacts on a solid barrier. The forces are usually gravity, centrifugal, and electromotive. Examples are removal of a solid from a liquid by impaction (filtration), gravity (settling), centrifugal force, and the attraction of charged particles in an electrostatic precipitator. One exception to these mechanisms is drying by evaporating unbonded water from a solid. In this case, separation of a liquid from a solid occurs by mass transfer. For example, the water mixed with sand can be removed by evaporating the water. Because many component separations require contacting two phases, like liquid-liquid extraction, component separation is frequently followed by phase separation. Phase separators can be classified according to the phases in contact: liquid-gas, liquid-liquid, liquid-solid, solid-gas, and solid-solid. Some of the more common phase separators will be discussed.
