Page 286 - Wastewater Solids Incineration Systems

248 Wastewater Solids Incineration Systems

TABLE 10.3 Typical fluid bed incinerator operating problems (continued).
Problem Cause Solution
4. Bed low 4a Cake heating value decreased 4a Increase cake feed rate.
temperature Lower fluidizing airflow rate.
4b Overfeeding of cake or increase in 4b Decrease cake feed rate.
moisture content
4c Fluidizing airflow rate too low and 4c Increase airflow rate and restart cake
feed stopped feed system.
4d Freeboard spray system defective 4d Check that solenoid valves are shut. Check
and water pouring into bed whether spray nozzles are worn; and
replace.
5. Freeboard high 5a Preheat burner firing at too high a 5a Lower firing rate. Increase fluidizing
temperature rate (if located in freeboard) airflow rate.
5b Freeboard spray system defective 5b Check whether water supply is adequate
and booster pump is operating; open all
manual valves. Check whether solenoid
valves are actuated. Check failed or
plugged spray nozzle by removing,
connecting to external water; replace if
defective.
5c Insufficient excess air 5c Decrease cake feed rate or increase airflow
rate.
6. Abnormal high 6a Fluidizing air nozzles plugged 6a Shut down incinerator and cool; remove
bed pressure drop sand and check bed nozzles.
6b Pressure taps clogged 6b Remove pressure taps and clean.
6c Too much sand 6c Open bed solids overflow pipe and drain
sand. Be extremely careful because sand
will be hot.
6d Clinkers formed in bed 6d Shut down incinerator and cool; remove
sand and clinkers.
7. Abnormal low 7a Pressure taps clogged 7a Remove pressure taps and clean.
bed pressure drop
7b Too little sand 7b Add sand to bed.
7c Too low fluidizing airflow rate 7c Increase fluidizing airflow rate
8. Abnormal high 8 Exhaust gas duct plugged 8 Shut down incinerator and cool; check
freeboard pressure ducting. Clean.
9. Abnormal low 9 Heat content of cake increased 9 Increase airflow rate or decrease cake feed
oxygen in gases rate.