(28b) Distillation Tray Fundamentals

Distillation column internals, such as trays or packings, are used as phase contacting devices. The most common types of distillation trays are sieve trays, valve trays, bubble cap trays, and dual flow trays. Of these, sieve and valve trays are the most common.

An understanding of the fundamentals of trays is the key to successful design, operation, and troubleshooting of trayed distillation columns. This paper provides an overview of distillation tray design and operations for the practicing engineer. A brief history of trays and trayed columns will be presented. New generations of high performance trays, including augmented crossflow, counter current flow and cocurrent flow trays, will be discussed. The performance differences between trays and packings will be summarized. Column designs that provide high energy-efficiencies will be briefly discussed.

Extensive video footage of tray operations will be shown, from commercial size columns with various distillation systems ranging from deep vacuum to high pressure