不规则烧结矿余热回收竖罐内气体阻力特性

Gas resistance characteristics in vertical tank with irregular sinter for waste heat recovery

为了准确地评价烧结矿竖罐式冷却工艺的经济性和可行性,对比研究了单粒级和多粒级烧结矿填充床内气体阻力特性。首先,利用排水法、等效球体积法和称重法等表征烧结矿颗粒特性;然后,利用自制固定床试验台测量了不同粒度下单粒级和多粒级烧结矿填充床内气体阻力;最后,通过修正获得了ERGUN形式的阻力关联式。研究结果表明:气体速度对单粒级和多粒级烧结矿的单位高度气体阻力(ΔP/L)的影响一致,均呈二次关系增加;当量粒径(d_(p))对单粒级和多粒级烧结矿的ΔP/L的影响不同,单粒级的ΔP/L主要受空隙率影响,导致其随着d_(p)增加呈指数下降,且衰减幅度也逐渐减小;多粒级的ΔP/L不仅取决于空隙率,还受粒度组成的影响,这导致ΔP/L不仅随着d_(p)增大而下降,还造成ΔP/L的衰减幅度先上升后下降;本文得到的阻力关联式可以准确地预测单粒级和多粒级烧结矿填充床内气体阻力,平均相对误差分别为3.59%和3.39%;多粒级的粒度分布比单粒级的更宽,导致相同当量粒径下单粒级的ΔP/L比多粒级的ΔP/L平均低25%左右,表明单粒级的阻力关联式不适用于多粒级。

To accurately evaluate the economy and feasibility of sinter vertical tank cooling process,the gas resistance characteristic in the packed bed with the mono-size and multi-size sinter was studied.Firstly,the characteristics of sinter particles were characterized by drainage method,equivalent sphere volume method and weighing method,etc.Then,the gas resistance in the packed bed of mono-size and multi-size sinter with different particle sizes was measured by self-made fixed bed test apparatus.Finally,the resistance correlation in the form of ERGUN was obtained by modifying.The results show that the influence of gas velocity on the gas resistance per unit height(ΔP/L)of mono-size and multi-size sinter is the same,which increases in a quadratic relationship.However,the effect of the equivalent particle size(d_(p))onΔP/L of mono-size and multi-size sinter is different.ΔP/L of mono-size is mainly affected by the voidage,which leads to an exponential decrease ofΔP/L and the decrease of its attenuation amplitude with the increase in d_(p).ΔP/L of the multi-size is not only determined by voidage,but also depends on the particle size composition.This not only makesΔP/L decrease with the increase of d_(p),but also causes its attenuation amplitude to ascend firstly and then descend.Furthermore,the resistance correlation obtained in this paper can accurately predict the gas resistance in the packed bed with mono-size and multi-size sinter with mean relative errors of 3.59%and 3.39%,respectively.However,the particle size distribution of multi-size is wider than that of the mono-size,which results inΔP/L of mono-size with about 25%lower than that of multi-size with the same equivalent particle size.This indicates that the resistance correlation of mono-size is not suitable for multi-size.