Abstract：A computational fluid dynamics method was used to perform single phase flow in a impeller-type turbulence mill. The internal flow field features including gas temperature, pressure,velocity, velocity gradient, turbulence kinetic energy, etc was analyzed with different rotating speed and back pressure to gain a preliminary knowledge of the material crushing mechanism and operating characteristic of the mill. The results indicate that circumferential velocity gradient in the gap of the impeller and the stationary casing is bigger than 15 000 s^-1. There exists a cliff structure in the gap which constitute the main grinding zone. The temperature rise is relatively large when the rotating speed is bigger than 6 000 r/min and it becomes more and more violent with the increment of the rotating speed. There exists a strong rotation of gas flow in the exit section which behaves as a forced vortex flow. As a result, pressure gradient develops along radial direction and negative pressure appears in the central part of the outlet pipe which causes back flow.

Keywords: turbulence mill; numerical simulation; single-phase flow; turbulent flow; back flow