Subtopic: Concentration and drying of liquid foods – evaporators, tray, drum and spray dryers
Question Statement:
In a spray dryer used for producing instant milk powder, atomization of the liquid feed into fine droplets is typically accomplished using:
Options:
(A) Rotary centrifugal disk or high-pressure swirl nozzle
(B) Plate and frame press
(C) Fluidized bed sparger
(D) Screw press auger
Answer Key:
A
Step-by-Step Solution & Explanation
Spray dryers require rapid atomization of liquid concentrate into microscopic droplets ($10 - 200\;\mu\text{m}$) to maximize surface area for instantaneous moisture evaporation within milliseconds. This is achieved via high-speed rotary wheel/disk atomizers or high-pressure pressure nozzles.