| In this paper, the tortuosity and the effective diffusion coefficient of porous particles in packed column under conditions of capillarity condensation was studied. The tortuosity of the porous particles is obtained by the single pellet string reactor (SPSR) method. Two kinds of porous particles that are alumina and Nickel loaded catalyst are selected for the experiments to get a better comparison. Set different column temperatures and bain-marie temperatures to get different conditions of capillarity condensation. Besides, The values of Kelvin radius are calculated under different experimental conditions. Analyse the data of tortuosity and the effective diffusion coefficient, combined with the Kelvin radius and pore size distribution of porous particles, and then discuss the trend of the tortuosity under conditions of capillarity condensation.The experiments and theory deduction conducted in this paper as well as the results are shown as follows:(1) Kelvin radius which calculated under the condition that column temperature is 120 degrees are all very small. It takes very little proportion in the pore size distribution of porous particles so that the effect of capillarity condensation can be ignored, so can be the change of tortuosity.(2) Kelvin radius which calculated under the condition that column temperature is 60 degrees are much larger. It takes more proportion in the pore size distribution of porous particles as the bain-marie temperature increases so that the effect of capillarity condensation are very notable,so are the change of tortuosity.(3) Two groups of experiments have been done to study the effects of increased and decreased bain-marie temperature on tortuosity of Nickel loaded catalyst.The results show that basic trend is similar in two kinds of conditions. The datas of tortuosity of decreased bain-marie temperature are a bit larger than the tortuosity of increased bain-marie temperature.
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