Coal particle combustion studied by holography.

The application of holography to the study of burning coal particles in free flight was examined. Resolution to about 3 microm was attained in the combustion zone of a flat flame burner. Both size and velocity of particles up to 75 microm in diameter were measured holographically. Holographic interferometry was also used. Basic combustion events in coal were recorded and are presented here which have not been observed previously. A comparison of images produced by in-line and off-axis holography also resulted from the study.