Spray drying of foodstuffs

Spray drying is a relatively gentle method used in various industries where temperature-sensitive products are handled. These products are in solution form and are fed into the spray dryer. Although the temperature inside the spray dryer is high, the short residence time makes the method still gentle.

The spray drying process consists of four steps, briefly described below:

1. Atomization of the Solution:
   The solution is atomized and finely dispersed into small droplets. This is often achieved using high gas flows combined with the solution or by passing the solution through a rapidly rotating nozzle.
2. Contact with Hot Gas:
   When the small droplets come into contact with hot gas inside the spray dryer, small particles form.
3. Evaporation of Moisture:
   The small particles dry from the surface, and it is essential for the particles to be small enough to ensure effective drying.
4. Particle Separation:
   The dry particles are separated from the gas. This separation is accomplished using cyclone separation, which utilizes centrifugal forces to collect particles in the gas. After the cyclone, any remaining small particles in the gas can be captured using bag filters.

Spray drying may need to be customized depending on the specific product to be dried, and additives or pretreatment of the material may be necessary.

RISE (Research Institutes of Sweden) can assist you and your company in developing raw materials, optimizing your spray drying process, and providing expertise. We have a pilot-scale spray dryer in our food-grade facility.