转炉高温烟气中喷吹除尘焦粉后O2含量变化规律

Variation law of O2 content after dedusting coke powder injection in high temperature flue gas of converter

为了解决目前煤气中O2含量超标导致煤气回收率较低的问题,提出向转炉汽化冷却烟道中喷吹除尘焦粉来降低烟气中氧含量的新方法。以热力学计算为基础,分析了焦粉在汽化冷却烟道内与烟气中各组分发生反应的可能性,探讨了不同烟气成分对反应的影响,并通过工业试验研究了不同喷吹速率对焦粉在烟道内的反应效果,以此来探索焦粉对煤气回收质量的影响。结果表明,焦粉与烟道中的O2反应生成CO的趋势最大,随着转炉冶炼的进行,煤气中O2的含量不断降低,当吨钢喷吹焦粉量从0kg/t分别增加到5、7和10kg/t时,煤气中O2体积分数达到回收标准(不大于2%)的时间分别减少了21.65%、40.55%和40.89%;煤气回收时间分别增加了29、77和104s;当吨钢焦粉喷吹量达到10kg/t时,回收煤气中平均氧体积分数则从0.855%降至0.358%。通过工业试验研究结果分析,证明了向汽化冷却烟道中喷吹焦粉的新方法回收超低氧煤气的可行性。

In order to solve the problem of low gas recovery caused by excessive O2 content in converter gas,a new method was proposed to reduce the oxygen content in converter gas by injecting dedusting coke powder into the vaporization cooling flue of converter.Based on the thermodynamic calculations,the possibility of coke powder reacting with each component in the flue gas in the vaporization cooling flue was analyzed,the effect of different flue gas components on the reaction was explored,and the influence of different injection rates on the reaction of coke powder in the flue was studied through industrial experiments,so as to explore the influence of coke powder on the quality of converter gas recovery.The results show that the coke powder preferentially reactes with O2 in the flue to generate CO.With the progress of converter smelting,the content of O2 in the gas decreases continuously.When the amount of coke powder sprayed per ton of steel increases from 0 to 5,7and 10kg/t,the time for O2 in the gas to reach the recovery standard(less than or equal to 2%)decreases by 21.65%,40.55% and 40.89%,respectively.Gas recovery time increases by 29,77 and 104s,respectively.When the amount of coke powder sprayed per ton of steel is 10kg/t,the average oxygen content in recovered gas decreases from 0.855% to 0.358%.The results of industrial experiments show that the new method of spraying coke powder into vaporized cooling flue provides the feasibility for the recovery of ultra-low oxygen gas.