Abstract: A process, for purification of a combustion flue gas from a garbage incineration plant having a chloride content and further contaminated with HF, SO.sub.2, NO.sub.

Abstract: A process for cleaning the surfaces of interior parts of two-stage flue gas desulfurization plants, which employ limestone as absorbent to form gypsum as the final product, such as guide plates and baffle plates and/or the discharge pipe and the bottom side of the feed hoppers, said interior parts being contacted by flue gas stream(s) and liquid absorbent. The process is characterized in that the parts and/or areas of said interior parts to be cleaned are washed periodically with process water or first with a portion of the absorbent suspension of the upper absorbent circulation and then with a portion of the process water.

Abstract: A method for determining the carbonate content of washing suspensions of flue gas desulfurization plants using limestone is carried out by first admixing the samples, being at a temperature of from 40.degree. C. to 70.degree. C., with an excess amount relative to the maximum possible sulfite content, of an iron(III) chloride solution for the oxidation of the sulfite to sulfate, and then by addition of an excess amount of sulfuric acid or another acid, measuring the amount of escaping gas corresponding to the carbonate content.

Abstract: A process for the removal of carbon-containing or nitrogen oxide-containing pollutants in low-dust flue gases by catalytic reduction, which is characterized in that a reducing agent is injected through nozzle(s) into the intermediate space of one stage of the economizer, said reducing agent is mixed with the low-dust flue gas in the tube bundles of the economizer, and the resultant reduction flue gas mixture passes catalyst layers located downstream of the economizer at a local velocity greater than 6.5 m/s.

Abstract: A method for measuring parameters in suspensions containing particles which have a specific gravity greater than the liquid, by means of measuring probes in the interior of a quiescent-flow vessel. The method includes tangentially introducing a stream of the suspension into the flow vessel at one end thereof and tangentially withdrawing it therefrom at the other end thereof, under the same direction of rotation. The device is adapted for measuring a descending or an ascending stream, whereby, for measuring an ascending stream, the diameter at the top of the vessel is larger than the diameter at the bottom.