BOILERS
DOE-HDBK-1018/2-93
Miscellaneous Mechanical Components
Fuel Boiler Components
Figure 9 illustrates a typical fuel boiler. Some of the components are explained below.
Steam drum -
The steam drum separates the steam from the heated water. The
water droplets fall to the bottom of the tank to be cycled again,
and the steam leaves the drum and enters the steam system.
Feedwater enters at the bottom of the drum to start the heating
cycle.
Downcomers -
Downcomers are the pipes in which the water from the steam
drum travels in order to reach the bottom of the boiler where the
water can enter the distribution headers.
Distribution headers -
The distribution headers are large pipe headers that carry the
water from the downcomers to the risers.
Risers -
The piping or tubes that form the combustion chamber enclosure
are called risers. Water and steam run through these to be
heated. The term risers refers to the fact that the water flow
direction is from the bottom to the top of the boiler. From the
risers, the water and steam enter the steam drum and the cycle
starts again.
Combustion chamber - Located at the bottom of a boiler, the combustion chamber is
where the air and fuel mix and burn. It is lined with the risers.
ME-05
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