Spray Dryer Working Principle
Spray dryer atomizes liquid materials into tiny droplets, which contact with high-temperature hot air to complete moisture evaporation within seconds. The core process includes four steps:
Feed Atomization Stage
Liquid materials (solution/suspension/emulsion) are dispersed into 10-200μm droplets by high-pressure pump or centrifugal atomizer to maximize contact area with hot air.
Heat Exchange Stage
Droplets contact with 120-350℃ clean hot air in countercurrent/cocurrent flow to achieve rapid heat and mass transfer (moisture vaporization).
Drying & Forming Stage
Moisture evaporates completely within 1-5 seconds to form powder or granular products without thermal denaturation.
Product Collection Stage
Dried products are separated by cyclone separator or bag filter, and tail gas is purified before emission.
This principle is especially suitable for heat-sensitive materials (e.g., probiotics, herbal extracts) to maximize retention of active ingredients and nutrients.
