Ascension pipe (AP) is an important pipe for guiding raw gas produced from oven to gas collection main (GCM) during coking.When opening AP water seal cap, due to the presence of residual volatiles from coke and residual raw gas in the carbonization chamber, it is inevitable that unorganized smoke and dust will be discharged into the atmosphere.The diffusion point of smoke and dust will change with the change of coke charging&pushing number. The main components of residual raw gas are C and H inorganic substances and a small amount of organic matter. By igniting and burning it, its pollution to the atmosphere can be greatly reduced. The automatic ignition device of the AP water seal cap the raw gas through a multi-point igniter installed at the outlet of the AP water seal cap, while avoiding the occurrence of "blasting".