Char characterization using image analysis techniques

Three different image analysis techniques for the characterization and analysis of the morphology of chars are presented and discussed in this paper. Each technique attempts to provide objective and repeatable results for the various morphological characteristics of chars produced in a drop-tube furnace or during pulverized fuel combustion. Each technique is described fully, together with the results of several experiments carried out to assess each method for its potential use on a regular basis. The repeatability of the distance transform method is tested and found to be within acceptable limits when 50 images are analyzed. The benefit of automated image-analysis systems is demonstrated by the distance transform method, which produces large quantities of information regarding the whole char sample as opposed to the assessment of single char particles.