Which device is used to remove dissolved gases from boiler feedwater in a steam system?

Which device is used to remove dissolved gases from boiler feedwater in a steam system?

• A. Deaerator
• B. Boiler drum
• C. Strainer
• D. Separator

Answer: (A)

Dissolved gases in boiler feedwater, especially oxygen and carbon dioxide, cause corrosion in the boiler and steam system. The device that removes these gases is the deaerator. It heats the incoming feedwater and brings it into contact with steam, driving out the dissolved gases and venting them away. By lowering the amount of oxygen in the feedwater, the deaerator protects heat-transfer surfaces and piping from corrosion, helping the system run more reliably. There are atmospheric and vacuum designs, but the essential idea is the same: remove non-condensable gases before the water enters the boiler. The other items have different roles. A boiler drum separates steam from water within the boiler and stores steam; a strainer filters out solid debris from the water; a separator removes droplets or separates phases in steam or feedwater, but none are specifically for removing dissolved gases from feedwater.

Dissolved gases in boiler feedwater, especially oxygen and carbon dioxide, cause corrosion in the boiler and steam system. The device that removes these gases is the deaerator. It heats the incoming feedwater and brings it into contact with steam, driving out the dissolved gases and venting them away. By lowering the amount of oxygen in the feedwater, the deaerator protects heat-transfer surfaces and piping from corrosion, helping the system run more reliably. There are atmospheric and vacuum designs, but the essential idea is the same: remove non-condensable gases before the water enters the boiler.

The other items have different roles. A boiler drum separates steam from water within the boiler and stores steam; a strainer filters out solid debris from the water; a separator removes droplets or separates phases in steam or feedwater, but none are specifically for removing dissolved gases from feedwater.