Effect of the secondary air distribution layer on separation density in a dense-phase gas–solid fluidized bed
Effect of the secondary air distribution layer on separation density in a dense-phase gas–solid fluidized bed
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DOI：
10.1016/j.ijmst.2015.09.014
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发表时间：
2015-11
影响因子：
11.8
通讯作者：
Bo Lv;Z. Luo;Bo Zhang;Yuemin Zhao;Chenyang Zhou;Wenchao Yuan
中科院分区：
文献类型：
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作者：
Bo Lv;Z. Luo;Bo Zhang;Yuemin Zhao;Chenyang Zhou;Wenchao Yuan
干法选煤以其无水耗的独特优势，成为目前煤炭选矿领域最重要的工艺。矿物干选研究受到广泛关注，特别是在干旱缺水的国家和地区。在密相煤气固流化床流化过程中，物料按密度分层，高密度物料层留在床底，高密度粗颗粒床层成为影响流化床稳定性的重要因素。在稳定流化阶段，少量大半径气泡是传统流化床流化不稳定的直接原因。二次布风床对气流的分散作用主要表现在气相区;当粒径超过13 mm时，二次布风床对上层流化层的密度稳定性有协同作用。当颗粒尺寸较小时，特别是小于6 mm时，颗粒会不断移动，导致二次风分布床的不稳定性，并扭曲上部流化床的稳定性。在最佳操作条件下，高密度粗颗粒层流化气固分离的可能偏差E可低至0.085g/cm ~ 3。
Dry coal separation has been the most significant process in the field of coal beneficiation to date, because of its special advantage of operation with no water consumption. Mineral dry separation research has received wide attention, particularly in countries and regions experiencing drought and water shortages. During the process of dense coal gas–solid fluidized bed beneficiation, the material is stratified according to its density; the high density material layer remains at the bed bottom, and thus the high density coarse particle bed becomes an important influencing factor in fluidized bed stability. In the steady fluidization stage, a small number of large radius bubbles are the direct cause of unsteady fluidization in the traditional fluidized bed. The dispersion effect of the secondary air distribution bed for air flow is mainly apparent in the gas region; when the particle size exceeds 13 mm, the secondary air distribution bed has a synergistic effect on the density stability of the upper fluidized layer. When the particle size is small, especially when less than 6 mm, particles will constantly move, accounting for instability of the secondary air distribution bed and distorting the stability of the upper fluidized bed. Under optimum operation conditions, the probable deviationEof gas–solid separation fluidized with a high density coarse particle layer can be as low as 0.085 g/cm3.