Disadvantage: High Capital and Overhead Costs
Spray drying racks up huge costs from the equipment required and from its continuous operation. Main and auxiliary equipment are equally expensive, regardless of atomizer type and dryer capacity. Spray dryers generally have low thermal efficiencies, due to the large volume of hot air that circulates in the chamber without contacting the particles. Additionally, spray dryers that utilize two-fluid nozzles require compressed gas for atomizing. Without factoring in labor and maintenance costs, the high energy and pressure requirements already add greatly to the overhead costs.
Disadvantage: Maintenance Issues
Spray dryer maintenance mostly involves issues with the nozzle used. One-fluid and two-fluid nozzles are particularly prone to clogging and abrasion at the nozzle mouth. Rotary disc atomizers, due to the number of moving parts in direct contact with the powders, suffer from internal corrosion. Finally, issues with powders sticking to the internal chamber walls further contribute to cleaning costs and profit losses.