How does the sweeper work? Is it clean? Will it raise a lot of dust?

The specific working principle is as follows:

 Working principle of road sweeper

The road sweeper is equipped with four sweeping brushes, with suction nozzles at the rear. The left and right front sweeping brushes sweep the garbage at the corner from the outside to the inside and focus on the scope that the middle brush can sweep. The middle brush sweeps the garbage to the front of the suction nozzle, and the suction nozzle sucks the garbage into the dustbin for storage.   

 In order to reduce the two dust pollution during the cleaning process, the road sweeper is equipped with a spray nozzle above the left and right front sweeping discs to produce spray to suppress dust.