What is the function of the steam drum in a water-tube boiler?

What is the function of the steam drum in a water-tube boiler?

• A. It serves as the primary fuel storage and delivery system
• B. It filters feedwater and removes dissolved minerals
• C. It separates steam from water, provides reservoir and distribution for feedwater and steam, and maintains pressure
• D. It acts as an exhaust gas silencer

Answer: (C)

The steam drum is the upper vessel where steam is separated from the water and where both steam and feedwater are gathered and distributed, helping to keep the boiler pressure stable. As water circulates through the tubes and boils, steam bubbles rise into the drum; inside the drum, devices and gravity separate the steam from the liquid so that relatively dry steam exits to the main line while the remaining water is returned down to the lower parts of the boiler to maintain circulation. The drum acts as a reservoir, buffering water level and providing a ready supply of water to the risers, while the steam space sets the pressure that the boiler operates at. Feedwater is introduced into the drum to replenish what is converted to steam, maintaining the proper water level and continuity of the steam supply. This role is distinct from fuel storage, water filtration outside of the drum, or exhaust silencers, which are handled by other parts of the plant.

The steam drum is the upper vessel where steam is separated from the water and where both steam and feedwater are gathered and distributed, helping to keep the boiler pressure stable. As water circulates through the tubes and boils, steam bubbles rise into the drum; inside the drum, devices and gravity separate the steam from the liquid so that relatively dry steam exits to the main line while the remaining water is returned down to the lower parts of the boiler to maintain circulation. The drum acts as a reservoir, buffering water level and providing a ready supply of water to the risers, while the steam space sets the pressure that the boiler operates at. Feedwater is introduced into the drum to replenish what is converted to steam, maintaining the proper water level and continuity of the steam supply. This role is distinct from fuel storage, water filtration outside of the drum, or exhaust silencers, which are handled by other parts of the plant.