Material handling dryers system controls

In gas dynamic atomization, a liquid stream is broken-up into small entities which are dried very quickly. Because the formation of droplets occurs in aerodynamic suspension, the material experiences no shear and the liquid temperature does not rise above the local dew point, despite high gas temperatures. Since drying and subsequent cooling are rapid, organic materials do not have time to oxidize, degrade, or experience any other damage. Food powders often exhibit better flavor, texture, and instant characteristics than comparable powders from other spray dryers. Because a low pressure stream of slurry is pumped and dispensed, the system can also handle corrosive and abrasive products easily. Control over particle size is normally better. Fig. 7.82 depicts SEM photographs of some typical products. 

Spray dryers can be controlled either by manual control system (MCS) or by automatic control system (ACS). MCS is restricted to small spray dryers or when the handled material dries easily. In other cases ACS should be adopted. The outlet air temperature from the drying chamber is the parameter that is controlled as it represents the quality of... 

---