The boiler or steam generator

In the boiler the coal is fired and steam is produced. Since dry, pulverized coal burns more completely and more quickly than chunks of coal, the coal is first ground to dust in large mills and dried with hot air. Then the pulverized-coal and air mixture is blown through the burners into the boiler, where combustion ensues. The energy contained in the coal is released during combustion. The boiler walls consist of a system of tubes through which water is pumped. The flue gas transfers its heat to the water, generating steam which then leaves the boiler at a temperature of well over 500 degrees and a pressure of 200 bar or more. The flue gas is cleaned subsequently.