采用PC6D型颗粒浓度测量仪,在多段分级转化流化床冷态实验装置上,测量了提升管中局部固体浓度,对颗粒聚团特性进行了实验研究.结果表明:径向上絮状物的时间分率Fc和絮状物内的颗粒浓度εsc在床层中心区(r/R＜0.6)较低,而在边壁区(r/R＞0.8)相对较高.提升管所有截面上各径向位置的Fc和εsc均随表观气速urg的减小和/或固体循环量Gs的增加而增加,轴向上操作条件对底部加速段Fc、εsc的影响明显高于对上部充分发展段Fc、εsc的影响;径向上操作条件对中心区Fc、εsc的影响显著高于对边壁区Fc、εsc的影响.在絮状物颗粒浓度0到εsmf范围内,得出絮状物内的颗粒浓度εsc与该处相应的局部颗粒浓度εs的变化关系式为εsc=3.33εs0.8.%Local solid concentration in the riser of MFB was measured with a fiber optic probe PC6D and the solid aggregate properties were studied.The experimental results showed that at the radial direction,the floccule time fraction Fc and solid concentration inside floccule εsc were low in the central region (r/R＜0.6) while high in the wall region(r/R＞0.8).For all the sections of the riser,the radial Fc and εsc increased with the decrease of superficial gas velocity ur,g and/or the increase of solids circulation rate GS.The effects of operating conditions on Fc、εsc in the center region were notably greater than those in the wall region in the radial direction.And in the bottom section,the effects were obviously greater than in the upper section in the axial direction.An empirical correlation εsc=3.33εs0.8 was therefore developed to describe the variation of solids concentration inside floccule with the local solids concentration,with the floccule concentration within the range of 0～εsmf.
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