Question: An industrial furnace uses natural gas (assume 100% CH4) as a fuel. The natural gas is burned with 20% excess air, and is converted completely to CO2 and water. The combustion products leave the furnace at 500°F and pass into the stack, which is 150 ft high and 3.0 ft ID. The temperature of the air outside of the stack is 65°F and barometric pressure is 745 mm Hg.
a. If the gases in the stack were standing still, what would be the stack draft (difference in pressure inside and outside the bottom of the stack)?
b. If the gases were moving upward in tbe stack at a rate of 10 Ws, what would be the stack draft., neglecting friction?
c. Including tbe effect of friction, estimate the expected flow rate. (The 10 ft/s given previously no longer applies). Make whatever simplifying assumptions you may feel necessary. µ = 0.03 CP.