The minimum feedwater inlet temperature to a...

🔍 Key Concepts

• Economizer purpose: how and why feedwater is heated by exhaust/stack gases before entering the boiler • Dew point of flue (stack) gases: what happens when metal surfaces and incoming feedwater are too cool relative to this temperature • Corrosion in economizer tubes: how low feedwater temperature can cause condensation and acid corrosion

💭 Think About

• Ask yourself: which factor, if it falls below a certain temperature, will cause moisture or acids from the stack gas to condense on economizer surfaces? • Think about which option represents a LIMIT you must stay above, rather than a design feature like surface area or a downstream temperature like superheater outlet. • Which choice is directly tied to protecting the economizer from corrosion caused by condensation, rather than just improving efficiency or heat transfer rate?

✅ Before You Answer

• Verify which choice is linked to condensation and corrosion in the economizer and stack area. • Eliminate any options that are primarily about heat transfer capacity or furnace performance, not about a minimum safe inlet temperature. • Confirm which parameter is commonly used in practice to set a minimum allowable feedwater temperature into the economizer.

The minimum feedwater inlet temperature to a boiler economizer is determined by the __________.

superheater outlet temperature

dew point temperature of the stack gas

surface area of the third stage heater

radiant heat transfer in the furnace

🔍 Key Concepts

💭 Think About

✅ Before You Answer