工业熔渣离心粒化数值模拟

Numerical simulation on centrifugal granulation of industrial molten slag

针对熔渣离心粒化过程,采用VOF法对粒化器中的气液两相流动进行三维瞬态模拟,主要对铜渣和高炉熔渣两种冶金渣在不同转速下生成的液丝与液滴特性进行了对比分析.结果表明:同转速下,与铜渣相比,高炉熔渣的破碎波长、尖端直径、破碎波长与尖端直径的比值、破碎长度均更大;不同转速下,同种熔渣破碎波长与尖端直径的比值趋于一致,破碎长度与尖端直径的比值与韦伯研究的结果相似;铜渣和高炉熔渣粒化产生的颗粒粒径均随转速的增大而减小,与高炉熔渣相比,铜渣在粒化过程中可以获得大量更小尺寸的颗粒;随着转速的增加,铜渣的平均粒径变化较小,更有利于从高温颗粒中回收余热.

Aiming at the centrifugal granulation process of molten slag,the three-dimensional transient simulation of gas-liquid two-phase flow in the granulator was carried out by the VOF method.A comparative analysis was conducted on the characteristics of liquid filaments and droplets generated by copper slag and blast furnace slag at different rotational speeds.The results show that the breakup wavelength,the tip diameter,the ratio of breakup wavelength to tip diameter,and the breakup length of blast furnace slag are greater than those of copper slag at the same rotational speed;the ratio of breakup wavelength to tip diameter of the same slag tends to be consistent at different rotational speeds,and the ratio of breakup length to tip diameter is similar to the conclusion of Weber′s research;the droplet sizes of copper slag and blast furnace slag decrease with the increase of rotational speed.Compared with blast furnace slag,a large number of smaller droplets can be obtained in the process of copper slag granulation;with the increase of rotational speed,the average droplet size of copper slag barely changes,which is more conducive to the recovery of waste heat from high-temperature droplets.