WICKE-KALLENBACH 法による高温でのコークスおよび黒鉛のガス有効拡散係数の測定

概要

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The WICKE-KALLENBACH method had not been applied to the high temperature measurement due to the difficulty of preventing gas leakage from the portion between the diffusion cell and a sample. However, this problem was overcome by devising the Na_2O-SiO_2 cement containing liquid phase at elevated temperatures. This technique made it possible to evaluate the effective diffusivity of Ar-He system through coke and graphite in a wide temperature range from 20 to 1300℃. The effective diffusivity for CO-CO_2 up to 300℃ and permeant fluxes for Ar and He up to 1000℃ were also measured. From these measurements, molecular, KNUDSEN and surface diffusion through pores could be evaluated distinctively, the results of which showed the temperature dependence of molecular diffusivity as T^<1.66>∿T^<1.69> in coincidence with the theoretical value by CHAPMAN-ENSKOG. The technique proposed in the present work was also applied to the in situ measurement of effective diffusivity of Ar-He through coke in the course of oxidation with CO_2 at 900℃. The variation of diffusivity with the increase in degree of reaction was found to be several times larger than that expected by the "Parallel pore" model.
社団法人日本鉄鋼協会の論文
1987-03-01