Experimental investigation of ignition behavior for coal rank using a flat flame burner at a high heating rate

Abstract

The ignition behavior of pulverized coal particles was investigated as a function of different ranks and sizes using a flat flame burner at high heating rate conditions (>105K/s). A high-speed camera was used to image the ignition process. Five coal types (anthracite, medium-volatile bituminous, high-volatile bituminous, subbituminous, and lignite coals) with particle sizes 150–200, 75–90, and <45μm were tested. The released volatile matter of medium- and high-volatile bituminous coal in the size ranges 150–200 and 75–90μm underwent homogeneous ignition. When the particle size is <45μm, high-volatile bituminous coal underwent homogeneous ignition, while medium-volatile bituminous coal underwent heterogeneous ignition. For particle sizes in the range 150–200μm, anthracite coal exhibited homogeneous ignition after primary fragmentation, whereas lignite coal underwent direct fragmentation and homogeneous ignition prior to ignition without primary fragmentation.