What are the basis for the flow type of centrifugal spray dryer

1. Downstream dryer
  In the downstream dryer, the sprayer enters the hot air and passes through the chamber in the same direction. The spray evaporates quickly, and the temperature of the dry air is quickly reduced by water evaporation. The product will not be thermally degraded, because once the moisture content reaches the target level, the temperature of the pellets will not increase much because the surrounding air is now colder. Dairy products and other heat-sensitive food products are best dried in a downstream dryer.

2. Countercurrent dryer

  The design of the spray dryer introduces spray and air into the two ends of the dryer, and enters the air as the nozzles are installed at the top and bottom. Countercurrent dryers provide faster evaporation and higher energy efficiency than current designs. Since dry particles are in contact with hot air, this design is not suitable for heat-sensitive products. Countercurrent dryers usually use nozzles for atomization, and the spray can be directed at air movement. Soaps and detergents are often used in countercurrent dryers.

3. Mixed flow drying

  This type of dryer combines co-current and counter-current. The air enters the mixed flow dryer, the upper and lower nozzles. For example, the counter-flow design, the mixed-flow dryer allows the hot air to dry the particles, so this design is not used for heat-sensitive products.