Subtopic: Regeneration efficiency in HTST pasteurizer
Question Statement:
In a continuous HTST plate pasteurizer, incoming raw cold milk at $5.0^\circ\text{C}$ is pre-heated in the regenerator section to $60.0^\circ\text{C}$ by outgoing pasteurized hot milk leaving the holding tube at $72.0^\circ\text{C}$. The regeneration efficiency of the pasteurizer is ________ $\%$ (round off to one decimal place).
Answer Key:
82.1
Step-by-Step Solution & Explanation
The regeneration efficiency $\eta_{reg}$ is defined as:
$\eta_{reg} = \frac{T_{regen} - T_{raw}}{T_{past} - T_{raw}} \times 100$
Given $T_{raw} = 5.0^\circ\text{C}$, $T_{regen} = 60.0^\circ\text{C}$, and $T_{past} = 72.0^\circ\text{C}$:
$\eta_{reg} = \frac{60.0 - 5.0}{72.0 - 5.0} \times 100 = \frac{55.0}{67.0} \times 100 = 82.1\%$