无低温腐蚀自预热式省煤器的开发与应用

Development and application of self-preheating economizer without low temperature corrosion

叙述了无低温腐蚀自预热式省煤器的工作原理及技术特点,通过新增锅炉给水预热器,以锅炉给水作中间热载体,利用省煤器出口的高温水加热进口的低温水,使低温段省煤器的进水温度高于烟气露点温度,彻底根除省煤器低温腐蚀。该省煤器具有系统简单,布置方便,使用寿命长,操作、维护方便,维修费用低等优点,目前已在多个硫磺制酸和硫铁矿制酸项目中得到应用,并取得了良好效果。

Working principles and technological characteristics of self-preheating economizer without low-temperature corrosion are described. Low-temperature corrosion of the economizer can be completely avoided by adding a boiler feed water preheater before economizer, where low-temperature BFW is heated by high-temperature BFW from economizer outlet as intermediate heat carrier, so the inlet water temperature of the economizer in low temperature section is higher than the dew point of off-gas. The economizer features simple structure, convenient arrangement, long service life, convenient operation and maintenance and low upkeep cost. It has been used in several sulphur-burning and pyrite-based sulphuric acid plants with good results.