🔍 Key Concepts

• Location and function of main generating tubes in a water-tube boiler • Where superheater and screen tubes are usually placed in relation to the furnace and gas flow • Appearance and placement of soot blower elements compared with water/steam-carrying tubes

💭 Think About

• Look at where arrow "O" is pointing in relation to the furnace and drum. Are these tubes directly forming the main evaporation surface between drum and lower headers, or are they in the hotter gas path above? • Compare the tube bank at "O" with the tube banks on the gas-outlet side where superheaters are often located. Which side of the boiler gas path is typically used for superheating versus generating steam? • Ask yourself: do soot blowers or screen tubes usually appear as large grouped banks like this, or as smaller elements/nozzles placed among other tubes?

✅ Before You Answer

• Verify whether the tubes at "O" connect directly between the steam drum and a mud drum/lower header, which is typical of generating tubes. • Confirm that the tubes at "O" are not located in the upper gas‑outlet region where superheater tubes are usually found. • Check that there are no soot blower nozzles or lance elements drawn at "O"; those are typically small devices inserted between tube rows, not entire tube banks.