We performed an experimental study to investigate the effects of various parameters on the attrition of bed material and its size distribution with increasing operation time in a recirculating fluidized bed (RCFB). The studied parameters included superficial velocity of fluidizing air, bed inventory, and spacing between the jet top and draft tube bottom (spacer height). The bed material was prepared from Indian Standard (IS) Grade I sand from sieves with a size range of 2.20–1.00 mm. Experiments were performed at ambient conditions, with the superficial air velocity ranging from 7.13–9.16 m/s, a bed inventory of 7–10 kg, spacing of 0.085 and 0.045 m between the jet top and draft tube bottom, and an operating time of 40 h. We investigated the influence of these parameters in terms of changes in the size distribution of particles, changes in the %-weight of particles of different size ranges, generation of particles with smaller diameters, the decrease of the downcomer bed height, variations in the coefficient of uniformity and coefficient of curvature, and material loss from entrainment of fines with increasing operation time. The mode of attrition was abrasion in all experiments. We found that with increasing operation time and other parameters (bed inventory, superficial air velocity, and spacer height) attrition of the bed material also increased. Generation and elutriation of fines were more pronounced at higher superficial air velocity, bed inventory, and spacer height.

我们进行了一项实验研究，以研究在循环流化床（RCFB）中，随着运行时间的增加，各种参数对床层材料的磨损及其尺寸分布的影响。研究的参数包括流化空气的表面速度，床层存量以及射流顶部和引流管底部之间的间隔（间隔器高度）。床层材料是用印度标准（IS）I级砂从尺寸为2.20-1.00 mm的筛子中制备的。实验是在环境条件下进行的，表观风速范围为7.13–9.16 m / s，床层存量为7–10 kg，射流顶部和引流管底部之间的间距为0.085至0.045 m，运行时间为40小时 我们根据颗粒尺寸分布的变化研究了这些参数的影响，不同尺寸范围的颗粒的重量百分比变化，直径较小的颗粒的产生，降液管床高度的降低，均匀系数和曲率系数的变化以及随着操作时间的增加而夹带细屑而造成的材料损失。在所有实验中，磨损方式均为磨损。我们发现，随着操作时间的增加和其他参数（床层存量，表面空气速度和垫片高度）的增加，床层材料的磨损也随之增加。在较高的表观空气速度，床层存量和垫片高度下，细屑的产生和淘析更为明显。均匀性系数和曲率系数的变化以及随着操作时间的增加而夹带细屑而造成的材料损失。在所有实验中，磨损方式均为磨损。我们发现，随着操作时间的增加和其他参数（床库存，表面空气速度和垫片高度）的增加，床材料的磨损也增加了。在较高的表观空气速度，床层存量和垫片高度下，细屑的产生和淘析更为明显。均匀性系数和曲率系数的变化以及随着操作时间的增加而夹带细屑而造成的材料损失。在所有实验中，磨损方式均为磨损。我们发现，随着操作时间的增加和其他参数（床库存，表面空气速度和垫片高度）的增加，床材料的磨损也增加了。在较高的表观空气速度，床层存量和垫片高度下，细屑的产生和淘析更为明显。