What controls the amount of water flowing into the steam generating tubes in a controlled circulation boiler?

In a controlled circulation boiler, the flow of water into the steam generating tubes is regulated primarily by orifices. Orifices are components that create a specific flow rate and pressure drop within the system, ensuring that water is supplied to the steam generating tubes at the correct rate necessary for efficient operation and heat transfer.

Orifices help maintain the desired flow characteristics by providing resistance to flow, which in turn helps in managing the circulation of water. This is crucial in a controlled circulation boiler, where maintaining an optimal flow rate is essential for preventing issues such as overheating or uneven heating of the tubes.

While valves, pipes, and pumps all play significant roles in the overall operation of a boiler, they do not specifically regulate the flow into the steam generating tubes in the same manner that orifices do. Valves can open or close to control flow but do not inherently regulate flow rates like orifices. Pipes facilitate the transport of water but are not responsible for controlling the flow rate directly. Pumps create the necessary pressure to move water through the system but do not manage the flow rates entering the steam generating tubes independently; that function is specifically handled by orifices.