Boiler stack gas temperature could be higher...

Boiler stack gas temperature could be higher...

Question 1 of 270705eccefa0bacbc34ba4d46e62

Boiler stack gas temperature could be higher than normal if __________.

Question 1 of 27070

Q

Boiler stack gas temperature could be higher than normal if __________.

🔍 Key Concepts

• combustion efficiency and where the main heat release is happening • difference between heat loss (to casing/air) vs. extra heat added to the gas stream • effect of secondary or delayed combustion on stack gas temperature

💭 Think About

• For each choice, ask yourself: does this condition tend to REMOVE heat from the gas flow, or ADD more heat to it before it leaves the stack? • Think about where the flame and combustion should normally be located, and what happens if significant burning is shifted farther downstream into the gas passages. • Consider which options would more likely cool the gases (through leakage or poor heat transfer) rather than actually raising their temperature at the stack.

✅ Before You Answer

• For each option, decide whether it mainly causes cooling/heat loss or additional burning/heat gain in the path to the stack. • Mentally trace the path: furnace → generating tubes → uptakes → stack, and ask where an abnormal hot-spot or delayed flame could occur. • Verify which condition could make the furnace region less efficient but leave more combustion to occur higher up, closer to the stack, raising the measured stack gas temperature.