Page 299 - Wastewater Solids Incineration Systems

260 Wastewater Solids Incineration Systems

FIGURE 11.2 Hearth sagging.

Rabble teeth located within the combustion zone will eventually deform and lose
their effective plowing action. In some cases the cake depth on the hearth will be
thicker than normal and the rabble arm with “bulldoze” the solids from side to side.
Plugged rabble teeth result from either soft slag that has sloughed off or a brick
that has become jammed between rabble teeth. This causes a local “bulldozing” con-
dition that can damage teeth and central shaft drive. The blockage should be
removed by stopping feed to the incinerator and stopping the central shaft.
Jogging the central shaft backward typically frees up the blockage. Remove the
slag/brick from the incinerator. If backwards jogging does not free up the blockage,
use long handled chisels and hoes to release and remove the blockage.