An Investigation Of Gas-solid Heat Transfer And Resistence Characteristics In Granular Layer Of Vertically-arranged Sinter Coolers

Sintering waste heat recovery is one of the important methods of energy saving in iron and steel industry. Efficient recovery and utilization of hot sinter waste heat is the core and key point of the whole sintering waste heat recovery. The air leakage problem of traditional coolers affects the heat recovery efficiency seriously. In order to solve this problem, vertically-arranged sinter coolers were adopted to improve the sealing performance and waste heat recovery efficiency. However, the flow resistance characteristics in granular layer will affect its heat transfer capability. Therefore, it is significant to investigate gas-solid heat transfer and resistence characteristics in the porous structure in granular layer.A one-dimensional steady state model was established to analyse the gas-solid heat transfer performance in ℃vertically-arranged sinter coolers of 230 t/h. Sinter inlet temperature (tsi=600～700 ℃), air inlet temperature (tgi=15～35 ℃) and ratio of gas flow rate to sinter flow rate(γ=550～700 Nm3/t) were analyzed for waste heat recovery. Recovered heat and air exergy were used as the criteria to compare waste heat recovery utilization under different operating conditions. It was found that at different sinter inlet temperature and air inlet temperature, the best gas solid heat transfer performance and maximum air exergy can be achieved by adjusting ratio of gas flow rate to sinter flow rate.In order to investigate the influence of flow resistance on gas-solid heat transfer performance. With the cold state experiment system of vertically-arranged sinter coolers, the influence of particle shape(sphericity from 0.62 to 0.66) and particle size(from 10.08 to 30.78mm) on the pressure drop were studied and bed macroscopic properties, flowing gas state were also analyzed. Finally, the pressure drop characteristics of sintered ore packed bed, fv=1219.3+2.711Rem, which is suitable for the modified Reynolds number range Rem=500～12000, is obtained. It is found that particle basic parameter characterization methods’ inconsistentence results in a large difference in pressure drop characteristic formula when obtained pressure drop curve was compared with pressure characterization in literature.