Fifty-thousand pounds per hour of a 20 wt% aqueous solution of NaOH at 120F is to be

Question:

Fifty-thousand pounds per hour of a 20 wt% aqueous solution of NaOH at 120°F is to be fed to an evaporator operating at 3.7 psia, where the solution is concentrated to 40 wt% NaOH. The heating medium is saturated steam at a temperature 40°F higher than the exiting temperature of the caustic solution. Determine:

(a) Boiling-point elevation of the solution

(b) Saturated-heating-steam temperature and pressure

(d) Heat-transfer rate

(e) Heating-steam flow rate

(f) Economy

(g) Heat-transfer area if U = 300 Btu/h-ft2-oF