Different methods of response data analysis in the time and frequency
domain were compared in a study of local and overall liquid mixing pro
perties of a gas-liquid-solid internal loop airlift reactor with low d
ensity particles. The reactor was analysed using the axial dispersion
model as a system consisting of five interrelated zones: draft, annulu
s and three top sections. Convolution in the time domain was the simpl
est and most accurate method of response data analysis, based on the p
redictions of the mean residence time. This method requires an analyti
cal solution in the time domain of the non-ideal flow model. In cases
when such a solution is not available (e.g. for the air Lift reactor a
s a whole), analysis in the frequency domain was used with almost the
same results.