Axial mixing coefficients in gas phase under nitrogen-water two-phase flow conditions at high pressure were measured in a packed column (0.15?m diameter,8.4?m high, with a 2.1?m packed section) by the technique of pul...Axial mixing coefficients in gas phase under nitrogen-water two-phase flow conditions at high pressure were measured in a packed column (0.15?m diameter,8.4?m high, with a 2.1?m packed section) by the technique of pulse injection of hydrogen. The packing was 350?Y Mellapak, manufactured by the Tianjin UnivTech Co. Ltd.. Nitrogen and water flowed countercurrently through the column at gas rates from 0.03 to 0.15?m·s -1 ,and liquid rates from 17.0 to 75.0?m 3·m -2 ·h -1 . The operation pressure varied from 0.10 to 1.70?MPa.The hydrogen concentration in gas phase was detected continuously by means of thermal conductivity. The one dimensional diffusion model was used for smoothing the experimental response curves with 7 per cent average errors. The experimental data showed that the axial mixing coefficient in gas increased with the increase of the interstitial velocity and the operation pressure. This trend may be due to the increase of the density and the viscosity of the nitrogen under high pressure. Practically no effect of the water loading on the axial mixing coefficient was observed.展开更多
X-ray Photoelctron spectroscopy (XPS) is used to study BSA adsorption on polysulfone (PS) membrane in static and dynamic conditions. The atomic compositions from XPS measurement show that the adsorption ratio, which i...X-ray Photoelctron spectroscopy (XPS) is used to study BSA adsorption on polysulfone (PS) membrane in static and dynamic conditions. The atomic compositions from XPS measurement show that the adsorption ratio, which is defined as the number of made of BSA over that of PS in the test scope, increases with the adsorption time, and dynamic adsorption is more severe than static adsorption at the same adsorption time. The fitting spectra indicate that there are chemical interactions with electron transfer between BSA and PS membrane. Further analysis shows that O 2 dissolved in BSA solution also participates in chemical interaction. These results can explain why the fouling of PS membrane by BSA solution is serious.展开更多
文摘Axial mixing coefficients in gas phase under nitrogen-water two-phase flow conditions at high pressure were measured in a packed column (0.15?m diameter,8.4?m high, with a 2.1?m packed section) by the technique of pulse injection of hydrogen. The packing was 350?Y Mellapak, manufactured by the Tianjin UnivTech Co. Ltd.. Nitrogen and water flowed countercurrently through the column at gas rates from 0.03 to 0.15?m·s -1 ,and liquid rates from 17.0 to 75.0?m 3·m -2 ·h -1 . The operation pressure varied from 0.10 to 1.70?MPa.The hydrogen concentration in gas phase was detected continuously by means of thermal conductivity. The one dimensional diffusion model was used for smoothing the experimental response curves with 7 per cent average errors. The experimental data showed that the axial mixing coefficient in gas increased with the increase of the interstitial velocity and the operation pressure. This trend may be due to the increase of the density and the viscosity of the nitrogen under high pressure. Practically no effect of the water loading on the axial mixing coefficient was observed.
文摘X-ray Photoelctron spectroscopy (XPS) is used to study BSA adsorption on polysulfone (PS) membrane in static and dynamic conditions. The atomic compositions from XPS measurement show that the adsorption ratio, which is defined as the number of made of BSA over that of PS in the test scope, increases with the adsorption time, and dynamic adsorption is more severe than static adsorption at the same adsorption time. The fitting spectra indicate that there are chemical interactions with electron transfer between BSA and PS membrane. Further analysis shows that O 2 dissolved in BSA solution also participates in chemical interaction. These results can explain why the fouling of PS membrane by BSA solution is serious.
