Spray drying has many benefits including the ability to control the dry particle size easily, the fluid-like flow properties of the spherical shape of the spray-dried particle, and the ability of the dryer chamber to remain dry. The surface area produced by the atomization of the liquid feed enables a short gas residence time, ranging from three to 40 seconds. The corrosion potential is also reduced.
The heat and mass transfer during drying occurs in the air as vapor films surround the droplet. This protective envelope of vapor keeps the particle at the saturation temperature. As long as the particle does not become completely dry, evaporation takes place and the temperature of the solids does not approach the dryer outlet temperature. The surface area produced by atomization of the liquid feed allows a short gas residence time, ranging from three to 40 seconds depending upon the application, which permits spray drying without thermal degradation. This allows for fast turn-around times.
The dryer chamber remains dry by design since a spray dryer is a gas-suspended process. Therefore, many corrosive materials can be processed with carbon steel as the primary material of construction of the spray dryer chamber, reducing capital costs.
Spray drying produces the most homogenous product for multi-component solutions and slurries. Each particle has same chemical composition as the mixed feed.