Tertiary Air Calculator

A third stage of air for advanced combustion control

Some multi-stage combustion systems - cement kiln calciners and certain low-NOx burner designs among them - inject a third stage of air (tertiary air) to complete combustion gradually, reducing peak flame temperatures that drive thermal NOx formation.

Worked example

For 1,000 kg/hr total combustion air with 20% primary and 50% secondary air:

Tertiary % = 100 - 20 - 50 = 30%

Tertiary Air = 1000 x 30% = 300.0 kg/hr (30.0% of total)

Staging combustion air across three phases like this gives combustion engineers finer control over flame shape, temperature profile, and fuel flexibility than a simple two-stage primary/secondary air split allows.