Under the extraction of exhaust fan, the air with dust powder comes into the dust precollection chamber.
The air with dust would flow down to dust drawer under the percussion of dam-board, and the speed will slow down, under the effect of intertance and dust powder, the big dust powder will fall down directly into the drawer.
Other thin dust powder will flow up together with the air, and will be attached on the surface of filter bag.
The filtered air will be exhaust out from upper part of cabin.
After a certain time, the dust power will be more and more on the surface of filter bag, the running resistance will become bigger.
At this time, the pulse blowback system will work automatically, the high pressure air could shock down the dust powder down from the filter bag's surface.