Abstract: A scrubber for desulfurization of gases, in particular flue gases of a boiler furnace includes two scrubbing zones each having a plurality of spaced arrays of nozzles for washing the gas with a respective washing liquid containing sulfur compound binding additives. At the bottom portion of the scrubber, the liquid discharged from the nozzles and containing sulfur compounds forms a sump to which limestone is added. From the sump two circulation systems extend. Each circulation system includes a pump which draws off a respective washing liquid from the sump and conveys the latter to the associated one of the scrubbing zones whereby whitewash or lime milk is introduced into one of the circulation systems.

Abstract: Desulfurization sludge from a flue-gas scrubber operating with calcium-containing additives is dewatered in a thin layer with precipitatable impurities in the liquid phase being precipitated out by neutralization and collected in a thin layer which is then rinsed. The presence of these precipitated impurities on the gypsum which is recovered by this process has not been found to be detrimental to the use of it as a construction material.

Abstract: A method of and an apparatus for the desulfurization of an industrial flue gas wherein the recirculating scrubbing liquid is sprayed with atomization into the scrubbing zone of a column and the droplet size, degree of atomization and gas flow velocity are controlled so that the pH of the scrubbing liquid within the scrubbing zone is substantially 3 to 6, preferably 4 to 5. In the sump oxidation is carried out by the introduction of oxygen to oxidize the calcium sulfite and calcium hydrogen sulfite which is formed to calcium sulfate.