TM 5-810-15
overflows into a surge tank which is the third and
than an ash pond system. Climatic conditions may
final stage of the closed recirculation system. The
require this system to be enclosed and piping heat
surge tank is sized to accommodate the overall
traced to avoid freeze up problems.
coaling and conveying water demands of the
bottom ash system. The decanted ash sluice water
6-4. Bottom ash handling system alternatives.
is returned to the ash conveying system for
a. Submerged drag chain mechanical transport
recycling. The ash sludge which is collected in the
system. Mechanical transport systems collect bot-
settling and surge tanks are returned to the
tom ash in a water impounded hopper. The hopper
dewatering bins by the use of sludge return pumps.
includes a water seal to prevent escape of the boiler
A dewatering system is much more compact but
furnace flue gases into the environment and to
usually more expensive to purchase and operate
prevent ambient air from entering the boiler. The
6-3
Previous Page
