So far, we have merely mentioned ashes and flue gas. These have to be removed
continuously. In the days of hand firing the removal of ash was simple though laborious.
The fireman merely raked the ashes out of the ash pit and carried it away in wheelbarrows.
Today, in large plants, the removal of ash is a complicated process requiring rather elaborate
equipment. So, we must add ash removal equipment to our diagram; also a chimney for the
removal of flue gas.