Page 117 - Boiler plant and distribution system optimization manual

102 Boiler Plant and Distribution System Optimization Manual

or carbon monoxide. • Consult the boiler operation and mainte-
nance manual supplied with the unit for
SAFETY details on the combustion control system or
methods of varying burner excess air.
• Extremely low excess oxygen operation can
result in catastrophic results.

• Know at all times the impact of the modifi-
FINDING THE SMOKE AND CO THRESHOLD
cation on fuel flow, air flow and the control
system.
Once your boiler is in good working order,
• Observe boiler instrumentation, stack and the next major step in improving efficiency and
flame conditions while making any changes reducing emissions is to establish the lowest level
engineering personnel or the boiler manu- of excess oxygen at which the unit can operate
facturer. safely and meet clean air laws.

Figure 9.26—Desirable smoke spot numbers for various fuels

Figure 9.27—The effect of smoke spot number on soot build up rate