Flue gas purification   WET Flue gas cleaning is determined by the waste to be removed and the local regulations! A two or multi-stage wet washer is normally connected in serial mode for widely differing or unknown waste materials or if high levels of pollutants are present. Chlorine and hydrogen fluorides, in addition to heavy metals, are mainly washed out in the first stage with an acidic solution (pH 1-3) and sulphur dioxide in the second stage with a basic solution (pH 7-8). The pollutants present in form of dust, salts and heavy metals and washed out by the chemical reaction are fed to a corresponding sewage treatment process and eliminated in concentrated form. CONFIGURATION FLUE GAS EMISSION ADVANTAGE incinerator post-combustion chamber waste heat boiler quencher wet scrubber exhaust fan stack Dust SO2 HCI HF heavy metals dioxins mg/Nm3 mg/Nm3 mg/Nm3 mg/Nm3 mg/Nm3 ng/Nm3 20 50 10 2 1 0.5 low flue gas emission without filter dust »» see flue gas purification systems - overview