THEORETICAL AND EXPERIMENTAL STUDY ON COAL COMMINUTION BY WATER JET

摘要

Water jetting used for coal excavation has been well known for a long time, but it used for coal comminuting is a new kind of application developed in resent years. As current traditional comminuting equipment is both energy intensive and inefficient, creating new method of comminuting may lead to significant energy saving. The comminuting system mainly composed two sets of chambers and enhancing pipes, during the comminuting process, granular coal particles are fed into the chambers, air bubbles accompanied with coal particles provide the chamber with air kernels for cavitations. The coal particles are comminuted to smaller pieces by the following forces: cavitation and hydro-wedge in the chamber, scraping forces between the particles and the inner wall of the pipe, and the colliding forces with its counterpart at the outlet of the accelerating pipe. In the paper, the authors give a detailed study on the self-resonated water jet comminuting system; several factors that influence the efficiency of the comminuting system have also been discussed. The result indicates that it works effectively and may have a potential market in the coal comminuting industry.