高炉大量喷吹煤粉的探讨

An approach to problems concerning massive pulverized coal injection

通过煤粉燃烧研究成果和喷煤实践的分析得出如下初步认识:煤粉在高炉风口区燃烧过程与一般工业炉不同,因风速高,煤粉停留时间短,煤粉在风口前端很难达到较高的燃烧率;氧煤枪对延长煤粉停留时间的作用有限,据国内外多数大喷煤量高炉的实践,200kg/t以下喷煤量不一定要使用氧煤枪,风口未燃煤粉并不可怕,因其气化率比焦炭高若干倍,能优于焦炭参加还原反应,有利于改善矿石高温性能,减少焦炭粉化和高炉顺行,粒煤具有节约动力、安全等优点,具有广阔的发展前景。

The combustion and gasification of pulverized coal in blast furnace are discussed.Combustion mechanism of pulverized coal in BF raceway is different from that in generial industrial furnace-As the blast velocity is high and the pulverized coal stays in a short time,it is hard to reach higher combustion efficiency of pulverized coal in front of tuyere.The oxygen-coal lance takes less effect on extension of staying time of pulverized coal,therefore there is no need for it in the case of coal injection rate of 200kg/t.Gasification rate of unburnt pulverized coal in raceway is approximately 7 times higher than that of coke,the former has priority in reducing reaction to the latter,and so it is favourable to improve the high temperature property of ore,to decrease coke degradation and smooth BF operation.Granular coal injection technology has advantages of saving in power,savety and so on.