Figure 4-8.—Vertical superheater.
As the steam passes through the super-
heater tubes, it is heated by the hot gases from
combustion, which flow around the tubes.
In some boilers, the superheater headers are
installed parallel with the water drum; and the
tubes are installed vertically (fig. 4-8). These are
called vertical superheaters.
Another boiler internal fitting is the desuper-
heater. It maybe located either in the steam drum
or in the water drum. All the steam generated in
a single-furnace boiler is led through the
superheater. However, since some auxiliary
machinery is not designed for superheated steam,
the steam must be cooled down. This is done with
a desuperheater. The desuperheater gets steam
from the superheater outlet, as shown in figure
4-9. The desuperheater is submerged in water
either in the steam drum or in the water drum.
As the steam passes through the desuperheater,
Figure 4-9.—Relative position of desuperheater tubes.
it is cooled for use in the auxiliary steam systems.
4-10
