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从鞍钢九号高炉和首钢二号高炉风口前回旋区取出了经过部分燃烧的煤粉试样进行研究。结果表明:煤粉离开喷枪刚进入直吹管就开始了挥发份的挥发和燃烧反应;直吹管可能是煤粉预热和预燃烧的一个重要空间。但是煤粉在风口前回旋区仍不能完全燃烧尽,其半焦仍有20—30%是在回旋区外滴落带中焦炭层内气化的,但不影响高炉正常操作。为了进一步扩大喷煤量、节约冶金焦,必须增加能加快风口前煤粉燃烧速度的措施。试验室模拟高炉风口前燃烧条件的燃烧动力学试验表明:对于两厂所用的无烟煤,进一步磨细到小于目前60—80%为-200mesh的水平(亦不宜小于40μm左右),以及增加鼓风含氧到30—40%,进一步提高风温,改进煤粉在直吹管内的分布,在全部风口中同时均匀喷煤,选用烟煤代替目前的无烟煤是有效的。对喷吹前和部分燃烧后的煤粉试样进行煤岩相鉴定表明:烟煤燃烧不仅在表面而且在其内部同时剧烈进行,无烟煤粒的内部燃烧所占比重较表面燃烧要小,特别是首钢京西无烟煤。这和烟煤具有较好的燃烧性一致。根据传热和传质原理推导出一组煤粉燃烧的数字模型,将本文中两座高炉和试验室燃烧炉条件代入数字模型用计算机求解得到与实际近似的结果。
From the Anshan Iron and Steel Company No. 9 blast furnace blast furnace tuyere front taken out after the partial combustion of pulverized coal samples were studied. The results show that when the pulverized coal leaves the straight blow pipe, the volatilization and combustion reaction of volatiles begin. The straight blow pipe may be an important space for the preheating and pre-combustion of pulverized coal. However, the pulverized coal in the tuyere before the tuyere still can not be completely burned, the charcoal 20-30% of its charcoal is still circulating outside the drip zone coke layer gasification, but does not affect the normal operation of the blast furnace. In order to further expand the amount of coal injection and save metallurgical coke, measures must be taken to speed up the pulverized coal combustion before tuyere. The combustion kinetics tests in the laboratory simulating the combustion conditions of the blast furnace tuyere showed that the anthracite used in the two plants was further ground to a level less than 200-80% (not less than about 40 μm) 60-80% Oxygen to 30-40%, to further improve the air temperature, improve the distribution of pulverized coal in the straight blow pipe, in all the tuyere at the same time coal injection, the choice of bituminous coal instead of the current anthracite is effective. Identification of coal samples before and after combustion showed that the combustion of bituminous coal was not only on the surface but also in the interior of it at the same time, and the proportion of internal combustion of anthracite particles was smaller than that of surface combustion, especially Shougang West Beijing anthracite. This bituminous coal has good flammability. According to the principle of heat transfer and mass transfer, a set of digital model of pulverized coal combustion is deduced. The conditions of the two blast furnaces and laboratory burner are substituted into the digital model and solved by computer.