During reduction, the ozone-containing gas is passed through a heated tube. In the process, ozone is split into oxygen. This method has the advantage over a pure metal oxide catalyst that moisture and impurities in the gas flow do not impair the efficiency of the ozone reduction in the long term, or only to an insignificant extent. Impairment can only be caused by deposits that deteriorate or even prevent heat transfer from the tube wall to the gas.
The efficiency of the reduction furnace depends on the gas flow and the ozone concentration. The higher the gas flow, the worse the efficiency.
The higher the ozone concentration, the better the efficiency.