制酸工艺中大型开工预热系统优化实践

Optimization practice of large-scale start-up preheating system in sulphuric acid process

冶炼烟气制酸工艺需要采用开工预热在72 h或更短的时间内将转化系统的烟气和触媒升温至430℃以上,确保生产正常开车。中原黄金冶炼厂新建配套制酸系统,生产能力达130万t/a,由于缺少同等大型生产能力的设计经验,开工预热系统在试生产中不能持续正常工作,严重影响了全厂的生产运行。针对此问题,冶炼厂对此设备从烟气进出口方向、上下气室结构和材质、支撑管结构和材质等进行了改造,改造后解决了上气室高温氧化、支撑强度差、下管板易烧损等问题,设备运行良好,节省了生产运营成本。

The sulphuric acid processs of melting flue gas needs start-up preheating system to raise the temperature of flue gas and catalyst of the conversion system to above 430℃within 72 hours or less to ensure normal production.A smelter newly built a supporting acid plant with a production capacity of 1.3 million t/a.Due to the lack of design experience with the same large-scale production capacity,the start-up preheating system could not continue to work normally during the trial production,which seriously affected the production and operation of the entire plant.In response to this problem,the smelter modified the equipment from the direction of flue gas inlet and outlet,the structure and material of the upper and lower air chambers,and the structure and material of the support tube.After the transformation,the problems of high temperature oxidation in the upper air chamber,poor support strength,and easy burning of the lower tube sheet were solved,and the equipment operated well and saved production and operation costs.