Page 312 - Wastewater Solids Incineration Systems

Incinerator Maintenance 273

TABLE 11.1 Items for inspection of fluid bed incinerators.

Refractory Check all refractory for cracks or broken pieces. This includes all openings for
nozzles. Repair or replace.
Bed support If hot wind box, inspect arch for cracks and loose or broken fluidizing air tuyeres
(nozzles). Repair refractory, replace loose or broken nozzles, and regrout.
If cold wind box, inspect refractory on construction plate for cracks and loose or
broken fluidizing tuyeres (nozzles). Repair refractory and replace loose or broken
nozzles.
Outer shell Buckling or bulging of shell and/or peeling paint indicate refractory failure. Locate
refractory failure and repair.
Preheat burner Inspect burner tile. Remove any clinker. If tile is damaged, patch.
Wind box Inspect fluidizing air nozzles from below for plugging.
Remove any sand that has accumulated on the floor of the wind box. This sand will
have leaked from the bed through the fluidizing air nozzles. Check that no fuel has
leaked from the bed into the wind box.
Sand removal may be required more often. Excessive accumulation of sand
indicates that one or more fluidizing air nozzles are defective.
Bed fuel guns Inspect each bed fuel gun. Deposits of carbon may form near the tip of the gun if
fuel oil is used. Rod out this obstruction.
Bed fuel guns can be inspected and cleaned during operation. However,
compressed air should be connected to the gun while reinserting to the bed.
Otherwise, reinsertion will be difficult and sand could lodge within the gun,
restricting fuel flow.

Bed pressure taps Inspect and clean bed pressure taps. This may be required during operation.
Freeboard water Inspect water sprays. Replace worn nozzles. If hoses are used, inspect and replace
sprays worn hoses.

Expansion joints Inspect all expansion joints on ducting. Remove any ash that has accumulated
between the liner and the expansion piece. If expansion joints are metallic, inspect
for cracks.
Instrumentation All instrumentation must be checked and recalibrated where necessary: pressure
transmitters, level transmitters, and flow transmitters. Inspect and, where damaged,
replace thermocouples and their wells. Replace gauge glasses if scratched or
otherwise damaged.

Gaskets Before closing inspection doors on the incinerator, inspect door gaskets. If damaged,
replace.