Abstract Sand-water slurry was investigated on an experimental pipe loop of inner diameter D = 100 mm with the horizontal, inclined, and vertical smooth pipe sections. A narrow particle size distribution silica sand of mean diameter 0.87 mm was used. The experimental investigation focused on the effects of pipe inclination, overall slurry concentration, and mean velocity on concentration distribution and deposition limit velocity. The measured concentration profiles showed different degrees of stratification for the positive and negative pipe inclinations. The degree of stratification depended on the pipe inclination and on overall slurry concentration and velocity. The ascending flow was less stratified than the corresponding descending flow, the difference increasing from horizontal flow up to an inclination angle of about +30°. The deposition limit velocity was sensitive to the pipe inclination, reaching higher values in the ascending than in the horizontal pipe. The maximum deposition limit value was reached for an inclination angle of about +25°, and the limit remained practically constant in value, about 1.25 times higher than that in the horizontal pipe. Conversely, in the descending pipe, the deposition limit decreased significantly with the negative slopes and tended to be zero for an inclination angle of about −30°, where no stationary bed was observed.

中文翻译：

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斜管中粗砂水浆浓度分布及沉积极限

摘要 在内径D = 100 mm、水平、倾斜和垂直光滑管段的实验管环上研究了砂水浆液。使用平均直径为 0.87 毫米的窄粒度分布硅砂。实验研究的重点是管道倾斜度、整体泥浆浓度和平均速度对浓度分布和沉积极限速度的影响。测量的浓度分布显示了正负管道倾斜度的不同程度的分层。分层的程度取决于管道的倾斜度以及整个泥浆浓度和速度。上升流比相应的下降流分层少，差异从水平流增加到大约+30°的倾角。沉积极限速度对管道倾角敏感，在上升管道中比在水平管道中达到更高的值。大约+25°的倾角达到最大沉积极限值，并且该极限值几乎保持恒定，比水平管高约1.25倍。相反，在下降管中，沉积极限随着负斜率显着降低，并且在大约-30°的倾角处趋于零，在该处没有观察到固定床。比水平管高25倍。相反，在下降管中，沉积极限随着负斜率显着降低，并且在大约-30°的倾角处趋于零，在该处没有观察到固定床。比水平管高25倍。相反，在下降管中，沉积极限随着负斜率显着降低，并且在大约-30°的倾角处趋于零，在该处没有观察到固定床。