Oxygen trim systems can be used to optimise the mix of flue gases by adjusting the ratio of air to fuel. The optimum percentages of oxygen (O2), carbon dioxide (CO2) and excess air in exhaust gases are shown in Table 1.
Fuel | O2 | CO2 | Excess Air |
Natural Gas | 2.2 % | 10.5 % | 10 % |
Coal | 4.5 % | 14.5 % | 25 % |
Liquid petroleum | 4.0 % | 12.5 % | 20 % |
Reduce excess air in the system by routine checks for leaks, as air from leaks will decrease optimisation.
