PL Air Classifier is a static powder separator in the real sense, has no transmission parts inside and is mainly composed of a group of stepped parallel plate grids. Materials to be separated fall down to the step in a trapezoid manner and fine powder will be separated from materials by means of separating airflow on the step and then conveyed to fine powder outlet. The particle size distribution and flow rate of coarse material and fine powder can be adjusted via adjusting separating airflow. Besides, coherent materials can be scattered well on the step during separation so that the separation efficiency rises.