| Blast furnace slag is the main by-product of the iron and steel smelting process.It has the characteristics of high slag discharge temperature and large output,and contains abundant high-quality heat.At present,the main treatment process of blast furnace slag is water quenching,and the treated blast furnace slag can be used as cement additive.However,this process only considers the material properties of blast furnace slag and does not consider its energy properties,resulting in high slag levels.Quality waste heat is wasted.In order to make full use of this part of the waste heat resources,domestic and foreign scholars and research institutions have tried to use the dry method to process blast furnace slag.In this paper,a new type of blast furnace slag dry processing technology has been developed.The device uses blast furnace slag particles as the cooling medium,and enhances heat exchange by rolling,avoiding the problems of wire drawing and uneven heat exchange existing in the current dry treatment process.Firstly,the effect of the device in treating blast furnace slag under different working conditions was studied through thermal experiments,and then numerical simulation was used to analyze the heat transfer of the treated blast furnace slag in the fluidized bed.The influence of the operating parameters of the device such as the motor speed R,the distance between the rollers L,and the height of the cooling medium feeding funnel on the thickness,temperature and vitrification rate of the treated slag was studied.,The effect of air velocity at the air inlet on the heat transfer of blast furnace slag particles.Finally,using the air temperature ratio at the outlet of the heat exchange device as an index,a multiple linear regression model is constructed,and a regression equation is established to determine the influence of each factor on the heat exchange efficiency.The experimental research shows that: the designed experimental device has the characteristics of producing blast furnace slag with high glass phase content,and the treated blast furnace slag flakes still have a certain waste heat recovery potential,which can realize the resource utilization of blast furnace slag and recover its heat;The temperature of the hot slag obtained after treatment increases when the rotation speed is small,the distance between the rollers is increased,and the height of the feed funnel is decreased;the thickness of the hot slag obtained after treatment is reduced by increasing the rotation speed,reducing the distance between the rollers,and increasing the height of the feeding funnel.;When the motor speed is 9 r/min,the distance between the rollers is 2 mm,and the height of the feeding funnel is 4 mm,the treated blast furnace slag presents a flake with a minimum thickness of 1.26 mm.At this time,the slag temperature is 832 K,and the glass body content is up to 89.8%.The simulation results show that the higher the inlet slag temperature and the larger the particle size,the higher the outlet air temperature.When the inlet air velocity is 3.96 m/s,the particle size is 1.2 mm,and when the inlet slag temperature is875 K,the outlet temperature is the highest.is 510.6K.The multiple linear regression equation of the outlet air temperature ratio under the action of various influencing factors shows that the inlet air velocity has the greatest influence on the temperature ratio,followed by the slag inlet temperature. |
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