徐旭, 唐川林, 胡东, 徐浩. 气力提升管三相流中气相状态对固相运动影响[J]. 煤炭学报, 2017, (11). DOI: 10.13225/j.cnki.jccs.2017.0487
引用本文: 徐旭, 唐川林, 胡东, 徐浩. 气力提升管三相流中气相状态对固相运动影响[J]. 煤炭学报, 2017, (11). DOI: 10.13225/j.cnki.jccs.2017.0487
XU Xu, TANG Chuanlin, HU Dong, XU Hao. Effect of gas state on solid movement with three-phase flow in riser[J]. Journal of China Coal Society, 2017, (11). DOI: 10.13225/j.cnki.jccs.2017.0487
Citation: XU Xu, TANG Chuanlin, HU Dong, XU Hao. Effect of gas state on solid movement with three-phase flow in riser[J]. Journal of China Coal Society, 2017, (11). DOI: 10.13225/j.cnki.jccs.2017.0487

气力提升管三相流中气相状态对固相运动影响

Effect of gas state on solid movement with three-phase flow in riser

  • 摘要: 钻孔水力开采中利用气力提升系统对地下矿浆进行提升时,气体状态(气相值的大小及其运动特性)对矿浆中矿石的运动及其提升效率将会产生重要影响。基于三相流理论和气泡动力学理论建立了提升管中固相运动速度模型,以陶瓷球形颗粒模拟矿石,利用自行设计的小型气力提升系统实验研究不同运行参数(气量值、淹没率)对颗粒提升量的影响,采用高速摄像技术获取不同气量值下管内气-液-固三相流运动图像序列,通过图像处理技术分析气相对固相运动的影响机理并与实验结果相佐证。结果表明:不同气量值下,气泡对颗粒的作用程度及作用形式并不相同;当气量值较小时,液体对颗粒运动影响较大,此时颗粒数量少、速度低且多随气-液混合相沿管壁位置提升;随气量值的增加,气泡对颗粒及液体提升作用明显,固-液混合相浓度及提升速度均趋于最大值并整体向管芯运动,相对于管壁,管芯处颗粒提升速度较大,此时管内整体呈不规则螺旋上升;持续增加进气量,气体流速过高,管内紊动加强,颗粒非连续提升且固-液混合相浓度显著降低。与淹没率相比,气量值的变化对管内固相运动的影响更为显著。实验结果与理论分析吻合较好,对钻孔水力开采工程应用具有指导意义。

     

    Abstract: The gas states (gas volume or movement characteristics of gas-phase) have an important effect on the move- ment and lifting efficiency of ores when using an air-lift system to lift the slurry in borehole hydraulic jet mining. The solid velocity model in riser was proposed based upon the three-phase flow theory and bubble dynamics theory. By sim- ulating the ore using the ceramic particles,the experimental study on the effect of different operating parameters (gas volume,submergence ratio) on particle lifting was carried out by using a self-designed airlift system. The moving ima- ges of gas-liquid-solid three-phase flow in different air-inlet was obtained by using the high-speed camera. The influ- ence mechanism of gas-phase on solid movement was discussed based on the image processing,moreover,the analytic results were compared with the experimental results. Results show that the influence modes of bubbles acting on solids is not the same under the different air volumes,as well as the influence degree of bubbles. Liquids have a significant effect on solid movement when the air-inlet is small,meanwhile,solids were lifted followed with gas-liquid phase along pipe wall,and its quantity and velocity is maintained at a low level. The bubbles have an significant effect on the pro- motion of solid and liquid with the increase of air-inlet,the concentration of solid-liquid phase and mixture flow veloci- ty are close to the maximum,the whole is moving to pipe center. In addition,the lifting velocity of solid in pipe center is greater than that at the pipe wall,and the moving trajectory of mixture flow in pipe is a spiral progress;however,the gas velocity is too high and the mixture flow turbulence is strengthened when the air-inlet is maintained in a high lev- el,the solids lifting is discontinuous and the concentration of liquid-solid phase is decreased significantly. In addition, compared with the submergence ratio,the effect of gas volume on the solid movement is more significant. The different characteristics of three-phase flow patterns is showed with the air-inlet changes,and the effect law of gas on liquid-sol- id phase is smaller. The experimental results gives a good fit to the numerical analysis which has a guiding significance for borehole hydraulic jet mining.

     

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