Please check the video
I, you need to wait 15 seconds after the ad. in chinese
and Video II
Cover is sealed by thread. There is no gasket there. Eventhough smoke is out of cover, the fire can not come up to the fuel bin.
Please note that burner is reverse flow. If you turn off the fan, there is not flame coming out. It is good for low&Slow smoking.
The flame is so strong that the burner can be used to build stove too
Please check the color of walls of burner. Walls above air inlet are not burnt,
no fire inside this section.