A solution of organic colloids $($solid material$)$ in water at $60\backslash$deg C is fed to a single$-$effect evaporator to produce $30\%$ wt concentrated solution. Saturated steam at $2$ bar absolute pressure is supplied to the heating system of the evaporator at a flow rate of $15250$kg $/$ h$.$ The operating temperature of the evaporator is $60$ deg $*$ C $($i$.$e$.$ the temperature in the evaporator$).$ The specific heat of the feed solution is $3\mathrm{.}8$J $/$ g $*$ K and the latent heat of vaporization of the solution may be taken equal to that of water. The solution has negligible boiling point elevation and all kind of heat losses to the environment may be neglected.

a$)$ Calculate the required feed flow rate $($kg $/$ h$)$ and solid content $($wt$\%$ solids$)$ of the feed solution in order to produce $2000$kg $/$ h $30\%$wt concentrated product solution.

b$)$ If the estimated overall heat transfer coefficient is $2200$W $/($m $^2)*$ K $,$ calculate the required heat transfer area in m $^2$

c$)$ Write down your recommendations $($maximum two$)$ to improving the operation $($i$.$e$.$ improving its efficiency$)$ of this evaporator.