Two-phase Vertically Upward Transport of Silica Sands In Dilute Polymer Solution: Drag Reduction And Effects of Sand Size And Concentration
Two-phase Vertically Upward Transport of Silica Sands In Dilute Polymer Solution: Drag Reduction And Effects of Sand Size And Concentration
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发表时间：
2007
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通讯作者：
Jin S. Chung;K. Lee;A. Tischler
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作者：
Jin S. Chung;K. Lee;A. Tischler
进行了石英砂在Xanvis L聚合物稀溶液中的两相垂直上升水力输送实验，研究了聚合物添加剂、石英砂粒径和浓度对压力梯度φ p/L或阻力的影响。砂粒有3种粒径：8~10、30~40和80~100目（2.36~2.00、0.6~0.425、0.180~0.150 mm）。浓度范围为2.2%至9.3%，流动回路由直径为2.54 cm的透明PVC管制成。在雷诺数10 < Re < 10的范围内测量压降和平均流速。稀聚合物溶液中的流动显著降低了水-砂混合物流动在更高的雷诺数范围内的阻力，其中阻力或阻力/L降低多达60%。然而，在较低的Re范围内，具有或不具有聚合物添加剂的混合物流动的Δ Rp/L变得大于不具有砂混合物的水的流动。在较高Re范围内出现较高的减阻或较低的阻力/升，而在单独的水流（没有混合物和添加剂）上，阻力随着较低Re而逐渐增加。随着浓度的增加，在较高的Re值下，与单独的水和聚合物添加剂相比，与没有聚合物添加剂的流动相比，阻力增加的趋势开始于较高的Re值。传统的看法是，颗粒越小，阻力或阻力p/L越小。而80 ~ 100目细砂颗粒的测得平均粒径比30~40目粗砂颗粒的测得平均粒径大。对于没有聚合物添加剂的流动，先前也报道了类似的结果。_______________
An experiment of a 2-phase vertically upward hydraulic transport of silica sands in the dilute polymer solution Xanvis L in a pipe is conducted to investigate the effects of a polymer additive, silica-sand particle size and concentration on pressure gradient ∆p/L or drag. The sand particles are in 3 sizes: 8~10, 30~40 and 80~100 mesh (2.36~2.00, 0.6~0.425, 0.180~0.150 mm). The concentration ranges are from 2.2% to 9.3%, and the flow loop is made of a clear PVC pipe 2.54 cm in diameter. Pressure drops and average flow rates were measured in the Reynolds number range of 10 < Re < 10. Flows in a dilute polymer solution significantly reduce the ∆p/L or drag of water-sand mixture flows in the higher Reynolds-number range, where drag or ∆p/L reduction is as much as 60%. In the lower Re range, however, the ∆p/L for the mixture flows either with or without the polymer additives becomes larger than the flows of water without the sand mixture. Higher drag reduction or lower ∆p/L occurs at the higher Re range, while drag gradually increases with the lower Re over flows of water alone (without the mixture and additives.) The trend of the drag increase over water alone with a polymer additive over the flows without starts at the higher Re values with the increase of the concentration. The conventional perception is that the smaller the particles, the smaller the drag or ∆p/L. Instead, the measured ∆p/L values for the 80∼100-mesh finer sand particles are larger than those of the larger 30~40 mesh sands. Similar results were also previously reported for the flows without polymer additives. _______________