The number of actual equilibrium stages determines the number of flashes that will occur. The more stages, the more complete the split, but the taller and more costly the tower. Most condensate stabilizers will normally contain approximately five theoretical stages. In a refluxed tower, the section above the feed is known as the rectification section, while the section below the feed is known as the stripping section. The rectification section normally contains about two equilibrium stages above the feed, and the stripping section normally contains three equilibrium stages.
Theoretical stages within a tower are provided by actual stage devices (typically either trays or packings). The actual diameter and height of the tower can be derived using manufacturer’s data for the particular device. The height of the tower is a function of the number of theoretical stages and of the efficiency of the actual stages. The diameter of the tower is a function of the hydraulic capacity of the actual stages.
