TM 5-815-1/AFR 19-6
belt, chain, bucket, or screw conveyor, or a
protected with abrasion resistant refractory in regions
combination of these.
where the gas flow changes directions.
(3) Coal can be stored in open piles or storage
c. Cyclone. In the circulating fluidized bed unit, the
silos. From storage, coal is fed to a crusher or
cyclone separator is lined with refractory to minimize
dryer as required for efficient burning. Crush-
abrasion and prevent heat losses.
ing of the coal is required when it is run-of-
d. Ash cooler. The ash cooler is also refractory lined
mine, for efficient burning, elimination of
to increase life of the unit due to abrasion of the solids
rocks in the bed, high moisture content, high
being handled.
ash content and when pneumatic conveying is
13-6.
Auxiliary equipment
necessary.
a. The following briefly describes the major compo-
(4) Drying of the coal is recommended when the
nents of auxiliary equipment for the fluidized bed
fuel moisture content exceeds fifteen percent
for all fluidized bed boilers except the
(1) Materials handling for fuel and limestone.
circulating fluidized bed boiler. The flue gas
The handling of fuel and limestone will vary
from the fluidized bed can be used for drying
depending on the source of supply and the
the fuel.
type of delivery. Delivery is usually by truck
b. Coal feed stream slitter. The dual bed unit has a
or rail car.
proprietary stream slitter which permits accurate feed
(2) The conveying systems for the fuel and lime-
of coal to multipoints under the bed for maximum
stone can be either a pneumatic or a mechan-
combustion efficiency.
ical system. The mechanical system may be
13-9
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