How a conduction dryer works and how to select one — Part II
Conduction drying is one way to handle a heat-sensitive material, control your drying process atmosphere to ensure final product quality, or use a waste-heat source to cut drying energy costs. This two-part article can help you determine if a conduction dryer suits your application. Part I, which appeared in the September 1997 issue, discusses classifying drying methods, understanding how a conduction dryer works, and comparing batch conduction dryers. Part II covers comparing continuous conduction dryers, selecting a conduction dryer, and running dryer tests.
A continuous conduction dryer can dry heat-sensitive solutions, slurries, pastes, and granules containing pigments, gypsum, clays, fine chemicals, fine coal, and salts and can be used for relatively short retention times. The dryer conveys as well as dries material; controlling the conveying speed controls the retention time. The continuous conduction dryer requires no material-handling labor, making its operating cost typically much lower than that of a batch unit.