Multiple choice

A continuous dryer was used to dry 12 kg/min of a blanched vegetable containing 50% moisture (wet weight basis) to give a product containing 10% moisture. As the dryer could handle feed material with moisture content not more than 25%, a part of dried material was recycled and mixed with the fresh feed. The evaporation rate in the dryer will be

  1. 2.08 kg/min

  2. 5.33 kg/min

  3. 3.33 kg/min

  4. 2.93 kg/min
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Using a mass balance around the dryer and the recycle system, the fresh feed moisture and recycle constraints dictate the flow rates. Solving the steady state material balances for water removal yields an evaporation rate of 5.33 kg per minute.

Keep practicing — related questions