Using a double effect evaporator, the concentration of a jus is to be increased from $5-$

$40wwt\%.$ The feed flow rate is $32000k\frac{g}{h}$ and enters the first effect at $40C.$ Steam at

$3\mathrm{.}5$atm is available as the heating medium for the first effect. A vacuum of $600mmHg$

is maintained in the second evaporator. Overall heat transfer coefficient is $500$ and $300$

kca$\frac{l}{h}.m^2.C$ in first and second effects respectively. Specific heat of the concentrated

solution is $0\mathrm{.}87$kca$\frac{l}{g}.$ C$.$ Calculate the heat transfer area of the two effects. The

calculated areas will be different; however, the commercial multiple effect evaporators

are designed to have the same heat transfer areas. How can you achieve the same

heat transfer area in both effects? Explain in detail.

The evaporators are cylindrical in shape and the residence time is $100$ seconds. Allow $5$

feet free space on top of the liquid level in the reactor. The ratio of the liquid height to

the reactor diameter is $1-3.$ The maximum coil diameter is $80\%$ of the evaporator

diameter $($this is not the pipe diameter$).$ Use the following table to find the coil diameter.

Also, you may use steam tables or properties of steam.

Make necessary assumptions followed by your justification.

Prepare a technical drawing.