ブロワーとダンパー

蒸気機関車 では、燃料 を燃焼する強さ、即ち火室 の温度は、取り入れる空気の流れに大きく依存します。より具体的には、空気中の酸素量に依存することを意味します。

The primary way to feed air to the firebox is by opening the regulator and cutoff fully, and propelling the vehicle. As the steam is expelled from cylinders out into the atmosphere through the chimney, with every gear cycle, it creates a vacuum in the firebox, drawing in fresh air.

さらに、風量を制御するために、ブロワーとダンパーという2つの制御装置が用意されています。

The blower is usually operated by a valve. When open, it releases some steam from the boiler to the chimney. This creates vacuum in the firebox, drawing in fresh air. However, since this airflow is vastly inferior to the acceleration airflow, the blower is only efficient when used on a stationary engine.

The damper is usually operated by a lever. When closed (pushed down) it chokes the airflow, drastically reducing fire temperature, even if the vehicle is accelerating. This is used to intentionally cut steam production when it is no longer needed, although doing so with a well-timed water injection is an even more efficient alternative.