holes opening for coating cleaning which avoids false air ingress at inlet chamber
leading to lower oxygen content resulting in lower NOx generation. Inlet chamber
refractory /castable must be anti-coating.
Also the kiln inlet seal should be leak-proof so that no atmospheric oxygen can
enter inside inlet chamber thus avoiding possibility of NOx generation from this
reason.- Higher Kiln Length: - Due to higher kiln length fuel fired by burner is fully burnt
which ensures better heat transfer resulting in lower fuel firing and air requirement
and zero CO at kiln inlet require less oxygen at kiln inlet help in reduction of
thermal NOx.
8.3 Primary Measures (^)
- NOx can be controlled by reducing the flame temperature of the main
and calciner burners, by maintaining a reducing zone at the back end of the
kiln, or (if all else fails) by dosing of a reducing agent to chemically destroy
the NOx eg. ammonia or urea solution - Low NOx burners are designed to generate a small amount of CO which
chemically reduces the NOx compounds to CO2 and N2. i.e. 2 NO2 + 4 CO
----> 4 CO2 + N2. - Utilization of AFR in pyro process can significantly reduce NOx emission
- Presence of Higher Volatile Matter in Fuel can significantly reduce NOx emission
- Removing NOx precursors
- Reduction of N in PC fuel
- Reduction of N in Raw material
- Process Control
- Stable operation (Expert system)
- Optimize Excess Air
- Avoid over burning
Burner Optimization - Low NOx design due to optimized flame control
- Minimize Primary and transport air
Kiln Feed burnability - Adjust LSF,SR, fineness
Installation of Low NOx Calciner - Split of Fuel, Raw Material
- Split of combustion Air
- Strong Reduction / Oxidation Zone
- High Temperature Combustion