Residence time distribution analysis of gas flow in irradiation chamber using radiotracer technique

The dry process to purify flue gases using electron beam accelerators was developed and is now in the status of industrialization. The proper design of the irradiation vessel and resultant gas flow pattern is very important to get high removal efficiency of toxic materials from flue gases. Radioisotope tracer experiments were conducted to study the residence time distribution of gas flow in a cylindrical irradiation vessel. A few mCi of gaseous radioisotope tracer Ar-14 was injected to the upstream of the vessel and the input and output response were measured with the NaI scintillation detectors. The same experiment was conducted after modification of the vessel by introducing 4 baffles. The experimental data were analyzed to calculate mean residence times and mixing characteristics of each system using a RTD analysis software. A method to estimate pollutant removal efficiencies of a irradiation vessel from the residence time distributions measured by radiotracer experiments was suggested. The analytical results were compared to evaluate the effect of the baffles on the removal efficiency of the plant. (author)