Abstract: Disclosed is a process system and a process for converting the sulfur-containing flue gas into the sulfuric acid. The process system comprises: a flue gas preheater, which for preheating the sulfur-containing flue gas to 15˜30° C. above its dew point, and the flue gas preheater has a glass tube as a heat exchange tube; a flue gas fan for boosting the pressure of the preheated acid process gas and transporting one part of which to a combustion furnace, and the other part of which to a process gas steam heater; a sulfuric acid steam condenser for condensing SO3 generated by the combined reactor into sulfuric acid. The device of the present invention can resist the fluctuation of SO2 concentration in the feed gas, and can realize considerable economic benefits and rational utilization of energy.

Abstract: Disclosed is a process system and a process for converting the sulfur-containing flue gas into the sulfuric acid. The process system comprises: a flue gas preheater, which for preheating the sulfur-containing flue gas to 15˜30° C. above its dew point, and the flue gas preheater has a glass tube as a heat exchange tube; a flue gas fan for boosting the pressure of the preheated acid process gas and transporting one part of which to a combustion furnace, and the other part of which to a process gas steam heater; a sulfuric acid steam condenser for condensing SO3 generated by the combined reactor into sulfuric acid. The device of the present invention can resist the fluctuation of SO2 concentration in the feed gas, and can realize considerable economic benefits and rational utilization of energy.