Experimental study on evaporation and combustion of single coal slurry droplet: (1st Report, behavior on a hot surface in a elevated temperature environment)

The combustion characteristics of a single CWM and COM droplet on a hot surface were investigated in a test furnace in which the ambient and surface temperatures were equivalent; this is to say, were at a uniform temperature. The droplet was simply set on the hot surface without using any suspending equipment like a silica thread. The following results were obtained. The ignition delay time of the COM droplet was shorter than that of the CWM droplet. The total burning time of the COM droplet was only slightly shorter than that of CWM. When the initial diameter of a droplet decreased, the total burning time was proportionally decreased by the square of the initial diameter. The effect of size distribution of the pulverized coal appeared on a surface combustion process of fixed carbon. The effect of coal properties on the surface combustion process was also studied using ten kinds of coals.