Sulphuric acid mfr. from sulphur, pyrite(s) etc. - by three stage contact oxidn. of sulphur di:oxide in five plate plant to reduce atmos. pollution

摘要

Sulphuric acid mfr. from S, pyrites or other sulphurous raw materials involves multistage oxidn. of SO2, with removal of the SO3 formed in the intermediate and final stages. A five plate plant is used for conversion, the first contact stage taking place on 3 plates and the second and third stage on the 4th and 5th plates. After the third contact and adsorption stages, the gases are discharged into the atmos. A suitable temp. distribution is maintained in the contact zones by utilising pt. of the heat from the SO2 conversion process in a heat exchange system. A high degree of oxidn. of SO2 and absorption of SO3 is attained, so that atmos. pollution is reduced 10 times cf. the double conversion method, using gases with ca. 15% higher concn. Heat exchanges with steel tubes (without cast iron sheath) can be used and catalyst consumption is reduced.