Most products are filtered, washed and subsequently dried. To this extent filtration and drying are interrelated. There are many individual pieces of equipment available that can accomplish the unit operations of filtration, washing and drying. The pressure-nutsche filter-dryer, designed for toxic chemical production, offers the optimum solution for conducting those multiple operations in a single process vessel.

An overview of conventional drying methods is presented followed by an examination of a new approach to filtration, washing and drying in pressure nutsche filter-dryers. The classic drying curve is used to illustrate the drying techniques. Design parameters for toxic chemical processing, equipment cleaning, automated controls, and validation are also described.

A methodology for formulating a test program to analyze filtration, washing, and drying systems is presented. The program describes the feasibility of this technology for improved product quality, reduced production cycle time, minimized worker and environmental exposures, and improved safety.