Spray drying involves both particle formation and drying, which makes it a special drying process. The feed is transformed from the fluid state into droplets and then into dried particles by spraying it continuously into a hot drying medium. Similar to fluid bed drying, flash drying, spray granulation, spray agglomeration, spray reaction, spray cooling, and spray absorption, spray drying is a suspended particle processing operation (Masters, 1991). The main differences between spray drying, fluidized bed drying and flash drying are the feed characteristics (fluid in spray drying versus solids); residence time (5 to 100 s for spray drying versus 1 to 300 min for fluidized bed) and particle size (10 to 500 pm for spray drying versus 10 to 3000 µm for fluidized bed).
KeywordsFeed Rate Droplet Size Wheel Speed Spray Drying Liquid Sheet
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