DECAULKING METHOD

PURPOSE:To enable to easily control the oxygen density of hot air by a method wherein the sensible heat in the gas generated during the decaulking work performed with the hot air specially produced for decaulking work is recovered in the heat recovery system in the form of steam and said steam and exhaust gas after decaulking work are added to the hot air for controlling the oxygen density of the hot air. CONSTITUTION:The hot air for decaulking work is produced at a hot blast generating furnace 7 and sent from a line 23 through lines 20 and a gas collecting pipe 3 and to a line 24 during regular decaulking work against caulking, which incidentally generates during the recovery of heat performed by the gas of a coke oven 1. In this case, the oxygen density of the hot air is controlled by adding the steam from the line 28 and the recycled exhaust gas after decaulking work from the line 38 to the hot air so as to obtain the hot air with the oxygen density of 3-10% measured with an oxygen densitometer O2I by sampling the hot air from the line 23. Said steam obtained from the line 28 is the sum of the sensible heat of the hot air and the combustion heat produced by decaulking work during the operation of a jet steam layer cooler 5 in the same manner as its operation at the heat recovery of raw coke oven gas.