A forward feed double effect evaporator concentrates $200$ kg$/$h of solution from $10\%$ to $50\%$ by weight solids. The feed temperature is $313$ K and the gauge pressures of the steam in the calandria$$s are $300$ kN$/$m$2$ and $60$ kN$/$m$2$ respectively. The condenser operates at a pressure of $14\mathrm{.}7$ kN$/$m$2.$

The heat transfer area in each effect is $14\mathrm{.}0$ m$2.$

Using the data given, calculate:$-$

a$)$ The steam economy

b$)$ The heat transfer coefficients in each effect

Data

Take Cp for all solutions as $4\mathrm{.}2$ kJ$/$kg K

Boiling point elevation in effects $1$ and $2$ are $5\backslash$deg and $12\backslash$deg C respectively.

Atmospheric pressure $=101.$