一概况我厂自一九六七年以来,一直采用三排风口冲天炉熔炼可锻铸铁,铸件废品率在18～20％左右,夏天甚至达到25％,其中由于铁水质量原因造成铸件报废的占总废品率的一半以上。生产过程中冷铁水多,铁水利用率低。八五年七月我们将两座三排风口冲天炉改为“两排大间距、倒置风口”冲天炉。一年来的生产实践证明 General situation I plant since 1967, has been using three-row outlet cupola smelting malleable iron, castings scrap rate of about 18 to 20% in summer even reached 25%, of which due to the quality of the cause of molten iron scrap accounted for the total More than half the rejection rate. Cold iron and more water in the production process, the utilization rate of hot metal is low. In August, 2005, we changed two three-row vents to “two rows of large spacing, inverted tuyere” cupola. A year of production proved