Numerical Study of Smoldering Combustion of Activated Carbon in Ⅱ Iodine Absorber

T. Liang[1], M. Liu[1], X. Liu[1], Z. Meng[1]
[1]Safety Engineering, Zheng Zhou University, Zheng Zhou, Henan, China
Published in 2014

Iodine absorber is a widely used purification equipment for purifying air in a nuclear power plant. In China, the common type is Ⅱ iodine absorber. Impregnated activated carbon is the main absorber within the iodine absorber. Because of the decays exothermic of radioactive iodine, heat is generated in the adsorption process. Carbon is a combustible material. Moreover, air is always supplied in the process. The three elements a fire needs to ignite are present. So it is necessary to study the fire risk of iodine absorber. COMSOL Multiphysics® software was adopt in the study. The effects of inlet velocity on smoldering combustion, the distribution characteristics of the velocity field, and the effect of thermal conductivity on the smoldering combustion were investigated in the study .The results showed that smoldering combustion is more stable when the wind speed was about 2m/s; that the utilization rate of activated carbon is uneven in the absorber; and that the smoldering flame is very hard to spread when the thermal conductivity was larger than 0.10Wm-1 • k-1.