Experiments presented in Fig.3 are marked bold. Outlying result is
underlined (it was detected as in the Section A).
Both for non-packed and packed sample tube, the values of axial
dispersion coefficients (the Peclet numbers values are of several tens)
indicate that the flow is neither plug flow nor perfect mixing under
operation conditions applied. It is rather unexpected result for the
packed vessel, the literature [15] indicates a high probability of
plug flow.
The results show that the transfer function and inverse Laplace
transform are very effective technique for solution of the model. It
helps in easier way to develop model of high precision. In the Appendix
2 we discuss results obtained for the same experiment and CFD model of
gas flow. The results presented show that transfer function-based model
fits the experiments better - deviations and confidence interval are few
times smaller. So, the models based on transfer function can be
recommended as the alternative for models coded using CFD programs.
Summarizing, the method discussed can be recommended to determine of gas
flow and axial dispersion coefficients. It should be pointed that the
method is fast. Excluding operation condition stabilization time, the
total time of measurement and calculations is in the order of minutes
(less than 15 minutes).