26 September 2006
Do not pile low-grade coal higher than 3 m (10 ft) and best grade
coal not higher than 4.6 m (15 ft), unless they are piled by roll-packing method.
Locate yard piles at least 15.3 m (50 ft) from other combustibles and important
Construct coal bins, silos, or bunkers entirely of noncombustible
material, preferably concrete. The structure should be roofed over to keep out
rain and snow, and the space above the coal sufficiently ventilated to prevent the
accumulation of gases given off by the coal. An elevated cone-shaped bin in
which the coal is fed at the top and removed at the bottom is recommended.
This arrangement prevents fine materials from collecting and remaining in the bin
for long periods. The coal at the bottom, which is most likely to be troublesome,
is the first to be removed. Coal bins, and when possible, bunkers and silos,
should be emptied during the summer shutdowns and other prolonged idle
periods. Provide automatic sprinkler protection if the existing storage facility has
combustible construction or occupancy other than coal. Provide access
openings for manual fire fighting operations.
Compact inactive coal piles, regardless of height to prevent
Provide the following where combustible conveyor belts are used to transport
An automatic sprinkler system. Hydraulically design the system to
operate 10 automatic sprinklers and 2 hand-held hose lines (e.g., two 35-mm (1-
1/2-in) hose lines). Sprinkler coverage cannot exceed 9.3 m2 (100 ft2) per
sprinkler. The system must be designed using a pressure of 70 kPa (10 psi) on
the end sprinkler. Water supply should be adequate for at least one-hour
duration. Interlock systems with the belt drive to shut down on sprinkler water
flow. In a conveyor enclosure less than 4.6 m (15 ft) wide, install a single line of
Provide either 35-mm (1-1/2-in) hose lines or hydrants at suitable
intervals such that the entire belt is accessible for fire fighting.
Provide each conveyor belt system with tamperproof devices
arranged to automatically shut off driving power in the event of greater than 20
percent belt slow down or misalignment of belts. Use interlocking devices to shut
off power to contributing conveyors.
In a pulverized fuel system, use components designed and constructed in
accordance with requirements of NFPA 85, Boiler and Combustion Systems