What is Spray Drying?
What is Spray Drying?
Spray drying is an elegant method to dry solid substances from aqueous or organic solutions, emulsions, and suspensions. It is a method of forming a dry powder from a liquid or slurry by rapidly drying with a hot gas.
This is the preferred method of drying and applications are found in all major industries ranging from industrial chemistry, pharmaceutical, biotechnology to food industry or materials which may require extremely consistent, fine particle size.
Dry milk powder, instant soups, solid dosage form pharmaceuticals, instant coffee, detergents and dyes are just a few examples of spray dried products on the market.
Air is the heated drying medium; however, if the liquid is a flammable solvent such as ethanol or the product is oxygen-sensitive then nitrogen is used.
The hot drying gas can be passed in as a co-current, same direction as sprayed liquid atomizer, or counter-current, where the hot air flows against the flow from the atomizer. With co-current flow, particles spend less time in the system and the particle separator (typically a cyclone device). With counter-current flow, particles spend more time in the system.
Spray drying applications
- Food: Milk Powder, Coffee, Tea, Eggs, Cereal, Spices, Flavourings, Blood, Starch and Starch Derivatives, Vitamins, Enzymes, Stevia, Nutraceutical, Colourings, Animal Feed, Infant food, Encapsulation of Flavors
- Pharmaceutical: Antibiotics Vaccines, Medical Ingredients, Additives, Biopharmaceutical products such as enzymes, hormones, amino acids, peptides, and proteins
- Chemical & Industrial: Paint Pigments, Ceramic Materials, Catalyst Supports, Microalgae, Pesticides, herbicides, fungicides, insecticides, fertilizers, Cosmetics.