In a thermal oxidizer, the exhaust air needing treatment is first pre-heated in an integrated heat exchanger using exhaust air that has already been treated. Subsequently, the pollutants in the exhaust air are oxidized at a temperature of 750 °C in the thermal oxidizer’s combustion chamber. The quantity of additional fuel required depends on the amount of pollutants in the exhaust air and the temperatures achieved in the pre-heating stage.
Further heat recovery systems can be installed downstream. Effective arrangements include heating circulating air or fresh air, supplying hot or warm water, heating heat transfer oil and steam generation.
Fitting a thermal oxidation system with a downstream oxidation catalyst cuts fuel consumption and lower carbon monoxide concentrations in the treated gas.
In practice, the oxidation combustionchamber often operates at temperatures that are far higher than those used by other manufacturing processes (such as drying systems). In other words the energy demand from the production is well below the possible energy recovery of the thermal oxidation system. To overcome this problem, the combustion chamber would need to operate on lower temperature. But this would lead to non-compliance with statutory emission thresholds as complete combustion of the volatile organic compounds (VOC) and other pollutants would not be achieved.