$2.$ A sugar solution containing $8$ wt$\%$ solids was concentrated

to $40$ wt$\%$ using a triple effect feed forward evaporator. The

feed rate is $22680$ kg$/$h at $70$ C $.$ The BPR os solutions

$($independent pressure$)$ can be estimated from BPR C $=1\mathrm{.}78$

x $+6\mathrm{.}22$x$2,$ where x is mass fraction of sugar in solution

Saturated steam was used as the heating medium and was

supplied into the shell side of the first effect at $104\mathrm{.}4$ kPa $($g$)$

The pressure in the vapor space of the third effect is $-87\mathrm{.}9$ kPa

$($g$).$ The heat capacity of the liquid solutions is Cp $=4\mathrm{.}19-$

$2\mathrm{.}35$ x kJ$/$kg$.$oK$.$ The heat solution is considered to be

negligible. The overall heat transfer coefficients in each

vessel has been estimated as Un $=3123,$ U$2=1987,$ and U$3=$

$1136$ W$/$m$?.$ K$.$

f each effect has

stating all your assumptions

$1$ Calculate the total area required.

$2.$Determine the steam rate used.

the same surface area,

$3.$ Determike the stream economy