Fluidization Characteristics of a Fine Magnetite Powder Fluidized Bed for Density-Based Dry Separation of Coal
Fluidization Characteristics of a Fine Magnetite Powder Fluidized Bed for Density-Based Dry Separation of Coal
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DOI：
10.1080/01496395.2012.669805
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发表时间：
2012-01
影响因子：
2.8
通讯作者：
Yuemin Zhao;L. Tang;Z. Luo;Chuncheng Liang;H. Xing;C. Duan;Shulei Song
中科院分区：
文献类型：
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作者：
Yuemin Zhao;L. Tang;Z. Luo;Chuncheng Liang;H. Xing;C. Duan;Shulei Song
气固流化床分离技术有利于节约水资源和煤炭资源的清洁利用。对0.15 ~ 0.06 mm细粒格尔达特B磁铁矿粉的流体力学特性进行了实验研究和数值模拟，以降低其粒径下限。结果表明，静态床层高度应控制在300 mm左右（如300 ~ 350 mm）。与含有0.3 ~ 0.15 mm大Geldart B颗粒的床层相比，细颗粒床层的气泡尺寸、数量和频率都要小，因此床层活性更高。细颗粒床的压降和密度均匀稳定，表明流化质量好。仿真结果与实验数据吻合较好，表明了仿真的正确性和有效性。对于细颗粒床层，应将表面气速调整为不大于1.8 μ m。此外，大粒度磁铁矿粉（< 0.3 mm颗粒含量94.23%,0.3 - 0.06 mm颗粒含量91.38%）在工业规模模块化示范系统中用于50-6 mm煤密度分选。进煤灰分由55.35%降至14.67%，可能误差E值为0.06 g/cm3。
Gas-solid fluidized bed separation technique is very beneficial for saving water resources and for the clean utilization of coal resource. The hydrodynamics of 0.15–0.06 mm fine Geldart B magnetite powder were experimentally and numerically studied to decrease the lower size limit. The results show that the static bed height should be controlled near 300 mm (e.g., 300–350 mm). The bubble size, amount, and frequency of the fine particle bed are smaller than those of the bed containing 0.3–0.15 mm large Geldart B particles, thus leading to a higher bed activity. The pressure drop and density of the fine particle bed are uniform and stable, which indicates a good fluidization quality. Furthermore, simulated results are consistent with experimental data, which indicates the correctness and effectiveness of the simulations. The superficial gas velocity should be adjusted to not more than 1.8U mf for the fine particle bed. Additionally, wide size range magnetite powder, which contains 94.23 wt% < 0.3 mm particles with a 0.3–0.06 mm particles content of 91.38 wt%, was used in an industrial scale modularized demonstration system for 50-6 mm coal density separation. The ash content of feed coal was reduced from 55.35% to 14.67% with a probable error, E, value of 0.06 g/cm3.