In view of the slag discharge problems in the process of drilling long drillings along the seam, it describes the principles and the basic conditions of the wind force slag discharge method, and illuminates the determination of two parameters: the minimum wind velocity of slag discharge and the required wind pressure. With the FLUENT fluid calculation software, it simulates the pressure loss, the wind velocity variation and the cinder particles motion in the whole flow field in the process of drilling. Finally, it gives the velocity vector of the airflow in the drilling, the motion trace of the cinder particles, the law that the velocity of the airflow in the drilling stem bore varies with the depth, the law that the velocity of the cinder particles varies with the changes of time and the length of the drilling, the law that the velocity of airflow varies with the changes of the drilling's depth, the law that the static pressure of the drilling varies with the changes of the drilling's length. This paper provides basis for solving the problems existed in utilizing the wind force slag discharge method.
