The working principle is to achieve gradual separation through the linkage of multiple roller screens. Material enters the multi-stage roller screen from the top of the machine, and the motor drives the rollers mounted on the screen plates to rotate. There are gaps between the rollers, allowing large materials to be moved forward by the screen plates, while small materials fall through the gaps to the bottom and are discharged by the conveyor belt. The gaps between each roller screen are adjustable to separate materials of different sizes. Specifically, it is divided into three stages: dirt or debris leaks through the gaps in the roller screens in the first stage, forming a soil pile; larger materials enter the second stage, where materials of appropriate particle size are discharged to form a small aggregate pile; finally, the large materials are conveyed out to form a large material pile, achieving three or two
separations.