Subtopic: Concentration and drying of liquid foods – evaporators, tray, drum and spray dryers
Question Statement:
In spray drying of milk or fruit puree, the process that atomizes the liquid feed into billions of microscopic droplets inside the drying chamber is achieved using a:
Options:
(A) Rotary centrifugal wheel atomizer or high-pressure swirl nozzle
(B) Fluidized bed sparger
(C) Scraped surface blade
(D) Perforated bucket conveyor
Answer Key:
A
Step-by-Step Solution & Explanation
Spray dryers utilize either high-speed rotary disc atomizers ($10000 - 25000\text{ rpm}$) or high-pressure swirl nozzles ($7 - 20\text{ MPa}$) to atomize liquid into a cloud of droplets of $20 - 150\text{ }\mu\text{m}$ diameter.