流化床液固共存区域团聚结构表观黏结特性

摘要

Fluidized bed agglomerates were generated by the TEB atomization nozzle,the sizes of original particles,nucleation agglomerates,coherence agglomerates,paste agglomerates were distinguished by the cascade screening method,and different agglomeration stages could be identified. The most stable heterogeneous agglomerates coexistence region was taken as the research object to analyze the structural and textural characteristics in the growth process. Nucleation agglomerates was the basic element inducing coherence agglomerates. Adhesive growth of agglomerates was accompanied by increased porosity. With the injection liquid continuously filling the pores, agglomerates were gradually saturated. Adhesive growth rates of agglomerates of any size in the coexistence region were the same. In spite of the same fluidization conditions of agglomerates in the coexistence region,moisture contents and solids volume fractions of nucleation and coherence agglomerates were obviously different.%通过TEB雾化喷嘴制造流化床团聚结构，利用层叠筛分方法对原始颗粒、成核聚团、黏结聚团、糊状聚团4种结构加以尺度区分，成功地实现了不同团聚阶段的分区域辨识。实验选取团聚结构最为稳定的异质共存区域为研究对象，对其黏结过程的表观结构特性和组织特性进行了分析。研究结果表明：成核聚团是诱导黏结聚团产生及增长的基本元素，团聚结构的黏结增长导致结构孔隙度随之增加，随着注入液体对孔隙结构的不断填充，结构逐渐趋于饱和，共存区域内任何尺度的团聚结构黏结增长速率均相同；尽管在异质共存区域内的团聚结构处于同一流化条件下，成核聚团及黏结聚团两者的水分含量及固体体积分数却表现出了明显的差异。