典型的干法脱硫系统是将脱硫剂(如石灰石、白云石或消石灰)直接喷入炉内。以石灰石为例，在高温下煅烧时，脱硫剂煅烧后形成多孔的氧化钙颗粒，它和烟气中的SO2反应生成硫酸钙，达到脱硫的目的。
A typical dry desulfurization system is to spray desulfurizer (such as limestone, dolomite or slaked lime) directly into the furnace. Taking limestone as an example, when calcined at high temperature, porous calcium oxide particles are formed after calcination of desulfurizer, which react with SO2 in flue gas to generate calcium sulfate, so as to achieve the goal of desulfurization.
干法烟气脱硫技术在钢铁行业中已经有应用于于大型转炉和高炉的例子，对于中小型高炉该方法则不太适用。干法脱硫技术的优点是工艺过程简单，无污水、污酸处理问题，能耗低，特别是净化后烟气温度较高，有利于烟囱排气扩散，不会产生“白烟”现象，净化后的烟气不需要二次加热，腐蚀性小；其缺点是脱硫效率较低，设备庞大、投资大、占地面积大，操作技术要求高。
The dry FGD technology has been used in large-scale converter and blast furnace in iron and steel industry, but it is not suitable for small and medium-sized blast furnace. The advantages of dry desulfurization technology are simple process, no sewage and acid treatment problems, low energy consumption, especially the high temperature of flue gas after purification, which is conducive to the chimney exhaust diffusion and will not produce "white smoke" phenomenon. The purified flue gas does not need secondary heating and has little corrosiveness. Its disadvantages are low desulfurization efficiency, large equipment, large investment, large floor area, and operation technology Ask for height.