Hirotaka Konno

The influence of particle size distribution of coal on the fluidity of coal—water mixtures

Abstract Experimental studies were carried out to investigate the influence of particle size distribution on the viscosity and maximum coal concentration in coal—water mixtures. The results show that coal—water mixtures prepared by mixing coarse and fine coal in the weight ratio of 7:3 or 6:3 possess excellent fluidity and high coal concentration. It was also discovered that it is desirable to have a large particle size difference between the coarse and fine coal in coal—water mixtures. A simple correlation method is proposed to arrange the apparent viscosity data for coal—water mixtures.

Natural‐convection heat transfer to air from a horizontal array of cylinders with different surface temperatures

Heat transfer measurements were made on natural convection around horizontal in-line arrays of cylinders whose surface temperatures were different from each other. Through the experiments for a three-cylinder array, a correlation was obtained for the heat transfer coefficient of the array-center cylinder. By using the correlation with some assumptions, the heat-flux distributions could be estimated for an array of five cylinders which were heated to their respective temperatures. Consequently, it was found that both the correlation and the method proposed here were useful in the estimation of heat-flux distributions for a horizontal array of cylinders.