| 摘要 |
Hitherto, waste gases were conditioned by the catalytic conversion of sulphur dioxide into sulphur trioxide and introduction of the sulphur trioxide into the waste gas flow. The particles entrained in the waste gas were then deposited in an electrostatic filter (3). The sulphur trioxide is introduced in a novel manner in that, before entering the electrostatic filter (3), the waste gas is guided through a gas discharge section (4) having coronae. In the coronae, OH radicals are generated from the water vapour entrained in the waste gas and react with the sulphur dioxide which is still present in the waste gas to form sulphur trioxide. The latter in turn reacts with water vapour to form sulphuric acid which condenses on the particles and increases the electrical conductivity of the filter cake deposited on the deposition electrodes of the electrostatic filter. In this way, the deposition capacity of the filter is considerably improved, even when waste gases from low-sulphur fuel combustion plants are purified, without chemicals having to be added to the waste gas. |
