The incense cones create backflow smoke by using an incense burner. It’s called “backflow” because the smoke goes down instead of up like regular smoke.
Backflow burners use a simple natural phenomenon. No tricks are required to create the effect; all you need is an Incense cone with a small hole in the bottom. The waterfall is created using these backflow cones and a special burner design.
We all know that burning incense releases warm air. Normally, the heat generated when we burn incense releases smoke and the difference in atmospheric pressure between the surrounding air and smoke (warm air) rises and carries the smoke.
Because the backflow cone is hollow, the cold air inside the burner also reaches the smoke. This cool air draws smoke through the burner holes, creating a waterfall effect.