Numerical Simulation On Gas Flow In Blast Furnace With The Injection Of The Gas Made From Coal

To reduce the smelting cost, the coke is mainly replaced by pulverized coal injection (PCI) in theblast furnace (BF). To improve the quantity and combustion ratio of coal, a lot of work of improvingPCI technologies and advancing equipments have been done, which has acquired significant effect.But PCI also brings about some negative impacts on smelting processes. Our research group putforward the new technology of coal gasification injection in2003. The process mainly use gasificationinjection made from coal instand of PCI at tuyere. The new technology takes advantage of coalgasification injection to replace PCI to reduce the complexity of BF smelting and avoid adverseeffects of PCI.On the basis of computation fluid dynamics (CFD) theory, the gas flow and distributioncharacteristics in BF with coal gas injection are obtained by mathematic model method in this paper.Two-dimensional mathematical model of BF tuyere area and whole BF are established, respectively.The formation process of tuyere cyclotron in the lower part of BF and the effect of wind speed onthe depth and height of tuyere cyclotron are simulated by Euler/Euler model. The size of tuyerecyclotron increase with increase of wind speed.The tuyere cyclotron is stable after1.0s in spite ofdimention of wind speed;In full-coke smelting conditions, O2in tuyere cyclotron is gradually vanished, CO2is increased atfirst and then decreased and meanwhile CO was generated greatly;In BF process with coal gasification injection, improving rich oxygen rate and increasing gastemperature in BF bottom can compensate the heat compensation of lower part in BF. It shouldeffectively combine the two methods for BF process with coal gasification injection;The raceway, dead stock, dropping zone etc were considered in the mathematical model. The gasflow field, temperature field, pressure field and the position of cohesive zone are gained.The temperature in BF decrease with H2increasing at the condition of constant CO content incoal gas. But the temperature in BF changes slowly after the H2content over15%; The temperature inBF increase of CO content when H2content in in coal gas is constant.Figure56? Table18? Reference142...