Abstract：In order to analyzed the acceleration characteristic of particle accelerated via supersonic nozzle in fluidized bed superheated steam jet mill, Fluent software was used to simulate the steam flow field of gas and particles and the particle acceleration features under the condition of different particle size and density were obtained. The results show that due to the influence of nozzle exits a airflow pressure matching with the environment, leading to shock and expansion wave in accelerating regional appear alternately which made the superheated steam flow velocity fluctuates up and down, the biggest swings around 5%. In the same acceleration of superheated steam flow field, the accelerate process of four different particles size is similar. The smaller of the particles size, the better of the acceleration performance and in the speed of the material having a diameter of5 μm diameter is about 2 times 45 μm. Besides, particle acceleration is inversely proportional with the density of particles.

Keywords: superheated steam jet mill; numerical simulation; Largrange model; particle acceleration characteristic