$1.$ For a production process, a triple$-$effect evaporator with direct feed is required; It will be used to concentrate a $20\%$ to $70\%$ sodium hydroxide solution. A stream of $70,000$ lb$/$h is fed from an atmospheric storage tank $($T$=77$F$)$; the vapor in the last effect is condensed at $120$F$.$ The values $$of the global heat coefficients $700,800$ and $1000$ Btu$/$ft$2$ h $$F for effects I, II and III.

If you want the economy of this evaporation system to increase, what alternatives would you propose to achieve this?

Calculate the values $$of the transfer area required for each effect, considering that they will all have the same area. The amount of heating steam, if the service area provides saturated steam at $173\mathrm{.}23$ psia; and the economy of the evaporator system.

Results with their formulas, procedure and corresponding units