Improving the efficiency and reliability of the spraying units for drying dairy products

The study and calculation methodologies for spray drying units used in the production of dry dairy products have been analyzed as one of the most effective and widely adopted methods in drying practice. The directions for improving the efficiency and reliability of spray drying installations are discussed through the enhancement of their technological schemes, specifically transitioning from a single-stage to a three-stage drying process. The reliability of the spray drying unit's operation is confirmed by preventing the accumulation of moist product on the walls of the drying chamber, achieved by employing an "air-bottom" design with the appropriate aerodynamic characteristics for the jet flow. The results of the investigation into the fluidized bed drying process of milk powder, as the second stage of drying, are presented. The working limits of the boiling process and the design and operational parameters of the fluidized bed chamber are determined. An improved methodology for the practical calculation of spray drying units for dairy products is proposed, based on the thermogram of droplet drying and experimental data on the active volume share, derived from tests of a typical dryer prototype. A computational analysis of the joint operation of the drying chamber and the fluidized bed chamber has been carried out. The results of scientific and research-engineering work aimed at improving spray drying installations are presented, with a focus on the transition from outdated single-stage spray drying with product cooling in pneumatic transport to a unified three-stage process, which includes spray drying, drying in a fluidized state, and vibratory cooling. The effectiveness of the implemented technical solutions is confirmed by the results of commissioning tests of the modernized drying units and their subsequent operation. The scientific and technical experience gained by PJSC "Kalynivka Machine Engineering Plant" (Kalynivka, Vinnytsia Region) in modernizing and commissioning spray drying units, along with the experience in manufacturing equipment for dairy product processing, such as high-temperature gas air heaters and vacuum evaporation units, serves as the basis for their serial production.