Fortschritte verfahrenstechnischer Forschung durch die Radionuklidtechnik

Abstract

AbstractAdvances in Process Research by Radionuclide Techniques. Modifications and transformations of materials and their technical implementation in process systems require movement of materials. Radionuclide techniques can greatly help in understanding and describing these mechanisms. Their advantage lies in the contactless measurement of radioactively labeled flows of materials by the radiation emitted even through thick walls of equipment. Even under rigorous process conditions (high pressures, high temperatures), for instance, residence time distribution functions can be determined at any point in a process system without interfering with the system. This specialized measuring technique is demonstrated by three examples selected from various fields of process technology. Radioactive tracer studies performed on a rotary kiln helped, inter alia, to establish a subdivision into process zones and to pinpoint areas of dust generation. Mixing and feeding actions were studied in a twin screw extruder equipped with a special screw and mixer disk arrangement. Tracer experiments conducted in two secondary settling basins indicate the differences in the mechanisms of movement of the aqueous phase if the mean residence time and the residence time distribution may be influenced not only by hydraulic loads, but also by design variants of the overflow flumes.