Study On The Explosive Characteristic And Combustion Law Of Pulverized Coal Injection With Pure Oxygen

Corex is a new type of iron making process. Introducing pulverized coal injection technology to corex process has special theoretic and realistic significance. The effect of coal category, position of coal lance, pulverized coal granularity, oxygen speed, pulverized coal consistency and pulverized coal ratio on explosive characteristic of pulverized coal with pure oxygen was systematically studtied using pulverized coal exploder designed by ourself. Under the condition of pulverized coal injection with pure oxygen, coal category has greatly effect to the explosive characteristic of pulverized coal. Wanshuiquan coal has the most explosive fatalness; Shenfu coal, Xinglongzhuang coal; 45%Shenfu coal+40% Xinglongzhuang coal+15%Taixi coal have obvious explosive fatalness; the explosive fatalness of Datong coal ,45%Datong coal+40%Xinglongzhuang coal+15%Taixi coal are feeble relatively; No evidences of explosive fatalness about Taixi coal, Yongxia coal and Bo'ao coal weren't found on the whole. The farther between discharge and hearth fringe is, the stronger explosive fatalness of pulverized coal will be. In this experimentation , when oxygen speed is up to 30 m/s and the distance between discharge and hearth fringe is controlled within 300mm, the burning pulverized coal has no explosive fatalness on the whole. The oxygen speed is a signify factor to explosive characteristic of pulverized coal, the faster of oxygen speed is, the smaller explosive fatalness of pulverized coal will be. When oxygen speed is up from 10m/s to 40m/s, according to the mutative law of the distance between flame and discharge and in view of the tuyere unblocking unassured in actual productive condition of corex process and adequate safety factor, when oxygen speed is up to 200m/s in corex production, position of coal lance should be controlled about 250mm to hearth fringe. Reducing pulverized coal granularity, increasing pulverized coal consistency and pulverized coal ratio are all propitious to increase the explosive fatalness of pulverized coal.The effect of coal category, position of coal lance, pulverized coal granularity, oxygen speed, pulverized coal consistency, pulverized coal ratio and injection ways of coal lance on burning characteristic of pulverized coal with pure oxygen was studied systematically. To ensure insufflation safety precondition, the ratio of pulverized coal injected from tuyere is higher than injected from cooler. Increasing the pitch angle of coal lance injection from cooler in proper range, the osculant time of pulverized coal and oxygen will be ahead, which is propitious to increase pulverized coal ratio. Increasing the distance between discharge and hearth fringe is propitious to enlarge the combustion space, which is benefit for burning of pulverized coal. Increasing the match of bituminite in mixed pulverized coal, Reducing pulverized coal granularity and increasing pulverized coal consistency are all propitious to improve burning effect of pulverized coal, yet increasing the pulverized coal ratio is bad for improving burning effect of pulverized coal.