论文标题
拉伸在石灰石粉末上的动态和准静态流程测试的极限
Stretching the limits of dynamic and quasi-static flow testing on limestone powders
论文作者
论文摘要
由于凝聚力的重要作用，粉末是一类颗粒物。粉末的流动行为取决于流量状态和压力，因此仅通过一个实验很难测量/量化。在这项研究中，比较了覆盖多种状态的最常用的表征测试：（静态，自由表面）安息角，（准静态，密闭）的（准静态，密闭的）环剪切内部摩擦的稳态稳态稳态稳态，以及（动态的，自由的表面）旋转鼓流角度，用于自由流动，中等和强烈地凝聚的石灰石燃料。自由流动的粉末在所有不同情况（设备）之间很好地达成了一致性，而中等和强烈的粉末的表现更为有趣。从旋转鼓中的流动角开始较慢，可以推断出零旋转速率的极限，但随后观察到从堆中测得的休息角要大得多，可能是由于其特殊历史而引起的。当我们将环剪切测试扩展到其最低限定应力极限时，在零旋转速率极限下，内聚粉末的内部摩擦稳态内摩擦与流动角（自由表面）重合。
Powders are a special class of granular matter due to the important role of cohesive forces. The flow behavior of powders depends on the flow states and stress and is therefore difficult to measure/quantify with only one experiment. In this study, the most commonly used characterization tests that cover a wide range of states are compared: (static, free surface) angle of repose, the (quasi-static, confined) ring shear steady state angle of internal friction, and the (dynamic, free surface) rotating drum flow angle are considered for free flowing, moderately and strongly cohesive limestone powders. The free flowing powder gives good agreement among all different situations (devices), while the moderately and strongly cohesive powders behave more interestingly. Starting from the flow angle in the rotating drum and going slower, one can extrapolate to the limit of zero rotation rate, but then observes that the angle of repose measured from the heap is considerably larger, possibly due to its special history. When we stretch the ring shear test to its lowest confining stress limit, the steady state angle of internal friction of the cohesive powder coincides with the flow angle (at free surface) in the zero rotation rate limit.
