Question

Potato slices weighing 50 kg is dried from 60% moisture content (wet basis) to 5% moisture content (dry basis). The amount of dried potato slices obtained (in kg) is ............ (Answer in integer)

Hint:

Drying problems usually preserve the dry matter. Always check which moisture basis is used (wet vs dry) and convert accordingly.

Answer 1

We are given:
- Initial weight of wet product = 50 kg 
- Initial moisture content = 60% (wet basis) 
- Final moisture content = 5% (dry basis)
Step 1: Convert initial moisture content from wet basis to dry basis
Moisture content (dry basis) is: \[ MC_{db} = \frac{MC_{wb}}{1 - MC_{wb}} = \frac{0.60}{1 - 0.60} = \frac{0.60}{0.40} = 1.5 \] Step 2: Use drying equation \[ {Final dry weight} = \frac{{Initial wet weight} \times (1 - MC_{wb})}{1 + MC_{db}^{{final}}} \] Here, final moisture content = 5% dry basis = 0.05 \[ {Dry matter in initial sample} = 50 \times (1 - 0.60) = 20 \, {kg} \] Now, dry matter remains constant. So for final dried product: \[ {Final weight} = {dry matter} \times (1 + MC_{db}^{{final}}) = 20 \times (1 + 0.05) = 20 \times 1.05 = 21 \, {kg} \] \[ \boxed{{Final dried weight} = 21 \, {kg}} \]