Question

Which type of drier is widely used for the production of dry yeast?

(a) Spray driers

(b) Roto–Louvre drier

(c) Fluidized bed drier

(d) Simple drier

This question was posed to me during an online interview.

This intriguing question comes from Aerobic Bioprocesses in chapter Mixed Cultures & Traditional Industrial Bioprocesses of Bioprocess Engineering

Answer 1

The correct option is (a) Spray driers

To explain I would say: Spray driers are the most widely used. A suspension with 10–20% yeast is atomized into a drying chamber and dried with hot air. The drying temperature and time are 50°C and 10–20 min, respectively.