Due to the shutdown of some coke ovens,the coke oven gas volume drops sharply,which directly causes temperature drop of Claus furnace.For this reason,COG must be added to maintain normal temperature of Claus furnace.The content of carbonyl sulfur (COS) in Claus tail gas is high after blending with COG.By continuously adjusting the gas blending amount into the Claus furnace,it can not only ensure normal temperature of Claus furnace,but also control the COS in tail gas not too high.