Experimental investigation of pressure letdown flow characteristics in dense-phase pneumatic conveying at high pressure
Experimental investigation of pressure letdown flow characteristics in dense-phase pneumatic conveying at high pressure
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DOI：
10.1016/j.powtec.2015.03.002
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发表时间：
2015-06
影响因子：
5.2
通讯作者：
C. Liang;J. Grace;Liu Shen;Gaoyang Yuan;Xiaoping Chen;Changsui Zhao
中科院分区：
文献类型：
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作者：
C. Liang;J. Grace;Liu Shen;Gaoyang Yuan;Xiaoping Chen;Changsui Zhao
对压力高达3.0MPa的输送设备的流动特性和压力下降机理进行了实验研究。考察了操作参数、颗粒尺寸和直径比对泄压系统不同截面压降的影响。结果表明，在密相气力输送过程中，压力下降会引起较大的压降。在固体质量流量一定的情况下，压降入口速度对不同截面压降的影响很小。随着固体颗粒质量流量、粒径或直径比的增大，收缩段和直管段的压降增大，而扩张段的压降与其他段的压降不同。直管段的压降占降压系统压降的70%以上。直径比、长度、质量流率和粉末性质决定了泄放压降。基于Barth加性理论推导的经验模型与实验结果吻合较好，相对偏差小于± 15%。
Experiments were conducted to investigate the flow characteristics and mechanism of pressure letdown of a conveying facility at pressures up to 3.0 MPa. The effects of operating parameters, particle size and diameter ratio on pressure drops across different sections of the pressure letdown system are examined. Results show that the pressure letdown causes a significant pressure drop in dense-phase pneumatic conveying. The effect of pressure letdown inlet velocity on the pressure drop through different sections is weak at constant solids mass flow rate. With increasing solids mass flow rate, particle size or diameter ratio, the pressure drops for the convergent section and straight pipe section increase, while the pressure drop of a divergent section differs from that of the other sections. The pressure drop of the straight pipe section is responsible for over 70% of the pressure drop through the pressure letdown system. Diameter ratio, length, mass flow rate and powder properties determine the letdown pressure drop. Empirical models, derived based on the Barth additive theory, show good agreement with experimental results, with relative deviations less than ± 15%.