中小型冲天炉多采用密筋炉胆换热器。为提高热风炉胆使用寿命,在设计炉胆时内筒一般要求使用厚约12mm 锅炉钢板,上、下口作成半径40～70的翻边圆角,如图1所示。据我厂观察,如果无翻边圆角,内胆和法兰(尤其是下端)的焊缝经常开裂,使内胆氧化烧穿,炉胆寿命降低。经比较,有翻边圆角 Small cupola use more dense hearth furnace gallbladder heat exchanger. In order to improve the service life of the hot blast furnace, when designing the furnace, the inner cylinder generally requires the thickness of about 12mm boiler plate, the upper and lower mouth made of the fillet radius of 40-70, as shown in Figure 1. According to our factory observation, if there is no filleted fillet, the weld of the liner and the flange (especially the lower end) is often cracked, the liner is oxidized and burned, and the life of the furnace is reduced. After comparison, there are fillet