Falling film evaporators are universally favored over rising film and batch pans for concentrating heat-sensitive liquid milk because:
Options:
(A) Liquid milk descends as a thin gravity-driven turbulent film inside tubes with an exceptionally short residence time (10 to 30 seconds), preventing heat scorching
(B) They operate under positive gauge pressures of 10 bar
(C) They do not require any condensing vacuum system
(D) They eliminate the need for steam
Answer Key:
A
Step-by-Step Solution & Explanation
Gravity spreading milk into a thin film enables high heat transfer coefficients and single-pass residence times under $30\text{ seconds}$, minimizing whey protein denaturation and Maillard browning.