The production of dry dairy powders and infant/baby formulas requires extremely sanitary design of the equipment. The system provided must handle a wide variety of difficult flowing and temperature-sensitive ingredients, including vitamins, nutrient additives and even probiotics. In addition, dependent upon the type of process and the processing environment, the equipment must be able to be cleaned by either dry or wet cleaning methods. Coperion pneumatic conveying systems and material handling components are utilized for the transfer of the raw ingredients as well as the final blended/spray dried product prior to packaging. The pneumatic conveying systems include both positive pressure and vacuum, dilute and dense phase.
Powdered infant formula is generally manufactured via dry blending or wet blending with subsequent spray drying. In the spray drying process the pasteurized and homogenized liquid is atomized in the spray dryer chamber. Water is evaporated and then dry powder deposits on the spray dryer bottom, where it is discharged with a sanitary Coperion rotary valve to a fluidized bed. There the product is typically dried further, cooled, sifted and then pneumatically conveyed to storage silos or packaging lines. The outlet air from the spray drying chamber still carries product (fines) which is normally ducted into cyclones and bag filters. From there the product is discharged with sanitary Coperion rotary valves into the fines return line. The fines can either be transported with pneumatic conveying to the fluidized bed or back to the top of the spray dryer for agglomeration purposes. The actual conveying path is selected by the sanitary Coperion WYK diverter valve. Moisture and warm temperatures are conducive to bacterial growth, therefore wet cleaning is normally applied in this process while dry cleaning is often typical in the process after the fluid bed dryer.