622 Fermentation and Biochemical Engineering Handbook The spray dryer is normally dry heat sterilized by a hot air system that is used for drying the product. All lines entering the spray dryer must be sterilizable. The selection of spray dryer size and solution atomizing device is best determined by trial runs on sized pilot equipment. As with freez drying, operational expense may limit spray drying operations to specific product applications. a flow diagram illustrating the spray drying process is shown in Fig 3 PRODUCT FEED AIR PRE- BLOWER/ HEPA FILTER HEATER FILTER ATOMIZER AIR FILTER DRYER CYCLONE PRODUCT COOLER PRODUCT OUT Figure 3. Spray drying process 9.0 EQUIPMENT PREPARATION All portable equipment and tools used in a sterile area must be thoroughly pre-washed with proper cleaning agents, final rinsed with WFl, and wrapped if required. These items are usually passed into the sterile are through a double door autoclave. Elimination of all particulate matter fre any object entering the sterile area should be a major design consideration622 Fermentation and Biochemical Engineering Handbook FILTER The spray dryer is normally dry heat sterilized by a hot air system that is used for drying the product. All lines entering the spray dryer must be sterilizable. The selection of spray dryer size and solution atomizing device is best determined by trial runs on sized pilot equipment. As with freeze drymg, operational expense may limit spray dyng operations to specific product applications. A flow diagram illustrating the spray drying process is shown in Fig. 3 DRYER CYCLONE PRODUCT FEEC b-21 Figure 3. Spray drying process 9.0 EQUIPMENT PREPARATION All portable equipment and tools used in a sterile area must be thoroughly pre-washed with proper cleaning agents, final rinsed with WFI, and wrapped if required. These items are usually passed into the sterile area through a double door autoclave. Elimination of all particulate matter from any object entering the sterile area should be a major design consideration