P$8\mathrm{.}1.$

Background: A boiler has the current blowdown at the rate of $8\%$ of the boiler feed water. Recommendation: Install the automatic blowdown control system and reduce the rate of blowdown to an estimated rate of $6\%.$

Question: What is the estimated cost saving?

Data

Water and sewage costs: $$0\mathrm{.}002$ per gallon

Water treatment cost: $$0\mathrm{.}002/$gal

Pressure of the boiler: $150$ psig

Atmospheric pressure: $14\mathrm{.}7$ psi

Steam generation rate: $100,000lb\frac{m}{h}r$

Makeup water temperature $60F$

Boiler efficiency: $80\%$

Natural gas fuel cost: $$8/$MMBtu

Hours of operation: $8h\frac{r}{?}$ day, $5$ days$/$week$,51$ weeks$/$year $(2040$ hr $)$

$1$ gal$-$water $=8\mathrm{.}34lbm-$water