Environmental Engineering Reference
In-Depth Information
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symptom 12.
Furnace burners are slagging up in the multiple
hearth furnace.
Causal factor:
Burner design
Corrective action:
Replace burners with newer designs that
reduce slagging.
•
symptom 13.
Rabble arms are dropping in the multiple hearth
furnace.
Causal factors:
Excessive hearth temperatures; loss of cooling air
Corrective actions:
Maintain temperatures within proper range;
discontinue injection of scum into the hearth; repair cooling air
system immediately.
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Excessive air pollutants are found in the multiple
hearth furnace stack gas.
symptom 14.
Causal factors:
Incomplete combustion (insufficient air); air pollu-
tion control malfunction
Corrective actions:
Raise air-to-fuel ratio; repair or replace bro-
ken equipment.
•
symptom 15.
Flashes or explosions are occurring in the multiple
hearth furnace.
Causal factor:
Scum or grease accumulation
Corrective action:
Remove scum or grease before incineration.
•
symptom 16.
Fluidized bed temperature is falling.
Causal factors:
Inadequate fuel supply; excessive sludge feed rate;
excessive sludge moisture levels; excessive air flow
Corrective actions:
Increase fuel supply; repair fuel system mal-
function; decrease sludge feed rate; correct sludge dewatering
process problem; decrease airflow rate.
•
symptom 17.
Oxygen level is low (<3%) in fluidized bed exhaust gas.
Causal factors:
Low airflow rate; fuel feed rate too high
Corrective actions:
Increase blower air feed rate; reduce fuel
feed rate.
•
symptom 18.
Oxygen level is high (>6%) in fluidized bed exhaust gas.
Causal factor:
Sludge feed rate too low
Corrective actions:
Increase sludge feed rate; adjust fuel feed
rate to maintain steady bed temperature.
•
symptom 19.
Fluidized bed control panel shows erratic bed depth.
Causal factor:
Bed pressure taps plugged with solids
