Method of purifying combustion product gases contaminated with dust and noxious gases

摘要

In order to achieve the removal of SO.sub.2 and NO.sub.x together with the entrained dust from the combustion product gases discharged from the combustion chamber of a steam generator in which sulfur-containing fuel, such as for instance lignite or brown coal is being burned, NH.sub.3 and/or NaHCO.sub.3 or chemical substances which release these compounds or react with the combustion product gases to form these compounds are introduced into the already partially cooled combustion product gases in the temperature region below 500 C. upstream of a dry separator, such as for instance a cloth filter. The entrained ashes are to contain CaO or Ca(OH).sub.2 and/or Na.sub.2 CO.sub. 3, especially from a previous desulfurization unit, prior to the introduction of the NH.sub.3 thereinto.