Q$\mathrm{.}3.$ A $2$ wt $\%$ aqueous salt solution is concentrated to $5wt\%$ in a single$-$effect evaporator. The feed rate to the evaporator is $5000k\frac{g}{h}$ and the feed is at $70C.$ The evaporator operates at $1$atm. Saturated steam at $170$kPa heats the evaporating solution. What heat transfer area is required if the overall heat transfer coefficient $($U$)$ is $3000\frac{W}{m^2}.K.$

$($Assumption: Since the feed is dilute, the solution has the same specifications as water$)$