铜闪速炉内颗粒受热过程的数学建模与数值优化

为了研究闪速炉冶炼颗粒着火延迟问题,建立反应塔内颗粒受热过程的数学模型,并进行计算.结果表明,在塔高0.6 m范围内,辐射换热对于颗粒的加热过程影响较大,而在反应塔0.6 m以下区域,对流换热占主导作用.鉴于强化对流换热过程对提高颗粒加热速度进而提高着火高度更有效,因此,建议采用高速热氧射流技术代替闪速炉内的天然气,使...

Mathematical modelling and numerical optimization of particle heating process in copper flash furnace

A mathematical model of the particle heating process in the reaction shaft of flash smelting furnace was established and the calculation was performed. The results indicate that radiation plays a significant role in the heat transfer process within the first 0.6 m in the upper part of the reaction shaft, whilst the convection is dominant in the area below 0.6 m for the particle heating. In order to accelerate the particle ignition, it is necessary to enhance the convection, thus to speed up the particle heating. A high-speed preheated oxygen jet technology was then suggested to replace the nature gas combustion in the flash furnace, aiming to create a lateral disturbance in the gaseous phase around the particles, so as to achieve a slip velocity between the two phases and a high convective heat transfer coefficient. Numerical simulation was carried out for the cases with the high-speed oxygen jet and the normal nature gas burners. The results show that with the high-speed jet technology, particles are heated up more rapidly and ignited much earlier, especially within the area of the radial range of R=0.3–0.6 m. As a result, a more efficient smelting process can be achieved under the same operational condition.