A Research And Simulation Of Hybrid Waste Heat Recovery Device Of Blast Furnace Slag

Energy conservation and improving energy efficiency is special significant to the steel industry. Blast furnace slag has production and calories as a main solid by-product in steel industry, so if effective measures can be used to recover heats from molten slag that will bring great economic and social benefits. At present the main processing technology for blast furnace slag is water quenching slag treatment, but there are some issues like recycling fewer calories, waste of water and environmental pollution etc. Dry treatment technology attract widespread attention thanks to it don’t consume fresh water and no pollution. As well as centrifugal granulation in the dry treatment technology has been discussed more and more in recent years.In this paper, a new method based on centrifugal dry granulation of dry treatment technology will be designed, It intends to obtain a waste heat recovery device combine centrifugal granulation, mechanical crushing, air quenching with recuperative heat transfer. The blade or grooves have angled were installed on the edge of the traditional table of centrifugal granulation, it not only can mechanical crushing, but also can control the direction of movement and distribution of slag particles.The moving track and heat transfer after centrifugal granulation of blast furnace slag can be simplified by the discrete phase model of numerical simulation software of CFD. Qualitative tracing of the trajectory of the slag particles analyzing the factors which influence the heat transfer after centrifugal granulation of blast furnace slag, such as air velocity, the grain size and mass flow of slag particles, air temperature, air outlet position and device size. Combined with the above analysis, the following conclusions can be got:(1) When the air velocity increases, the temperature drop of the slag particles increases, the temperature of air outlet decreases, but the surface of the water-cooled wall’s increases.(2) When the grain size of slag particles increases, the temperature drop of the slag particles is reduced, the temperature of air outlet and the surface of the water-cooled wall are all reduced.(3) When the mass flow of slag particles increases, the temperature drop of the slag particles is reduced, the temperature of air outlet and the surface of the water-cooled wall increases.(4) When the air temperature increases, the temperature drop of the slag particles is reduced, there is no effect on the movement of the slag particles and the surface of the water-cooled wall increases.(5) Air outlet located on the right side near the surface of the wall which is conducive to the heat transfer of slag particles and air.(6) With the increasing of the size of the device, the flying distance of slag particles become longer and longer, the spatial distribution of slag particles is more dispersed than before, but if the size of the device is too large, the slag particles will fall directly to the bottom of the device and can’t touch with the surface of the wall so that the temperature drop will reduce.The research methods and results of this paper can provide theoretical support for the further research, and provide some guidance for the design and improvement of the heat recovery device.