Concerns on centrifugal classifiers, of which have cut sizes are below few micrometers, have been increased and it is prospected to be used in extensive industries, such as manufacturing the fine minerals, cosmetics, advanced electric materials, and life science. This paper reviews the recent progress of research and development on the centrifugal classifiers. General categorization of classifiers for feeds was assessed and separation mechanism of the classifiers was followed. History of centrifugal classifiers was explored and some points to be improved were briefly indicated. Fundamental theory of the classification by centrifugal classifiers was pearly studied, and advanced and further understandings on factors affecting the separation or grading efficiency are described. Factors determining the classification precision and efficiency of centrifugal classifiers, such as geometry, rotational speed and inclined angle of rotating vanes, feed and air flow rates, and rotor dimensions are reviewed.

In this study, we devoted to kinetic measurement of the catalytic oxidation of iron-containing flame soot particles and better understanding the role of catalytic particles on carbon oxidation in particular at low temperature, targeting on autothermal regeneration of diesel particulate filter by diesel exhaust gas. Carbon-based Fe-containing particles generated by spraying ferrocene-doped diesel fuel in an oxy-hydrogen flame are tested and compared with a commercial carbon black powder for thermogravimetric analysis (TGA), secondary ion mass spectrometry (SIMS), Fourier-transform infrared spectroscopy (FTIR), Induced coupled plasma-Atomic emission spectroscopy (ICP-AES), and High-resolution transmission electron microscopy (HR-TEM). As a result, we found that a small amount of the ferrocene addition led to significant reductions in a on-set temperature and an activation energy of the carbon oxidation as well. An oxygenated surface complex forming at the particle surface could be thought as active species that would be readily consumed in particular at low temperature.

Nanosize ZnO particles were prepared by oxidation of zinc vapor and the particle growth was modeled by a coagulation model by assuming that the characteristic time for reaction was much shorter than coagulation time and residence time (${\tau}_{reaction}{\ll}{\tau}_{coagulation}{\ll}{\tau}_{residence}$). Experimental measurement of zinc oxide particles diameter was consistent with the predicted result from the coagulation model. For practical purpose of predicting zinc oxide size in areosol reactor, the constant kernel solution is concluded to be sufficient, Uniqueness of nano-scale property of zinc oxide was confirmed by the higher photocatalytic activity of zinc oxide than nanosize titania particles.