Beijing Key Laboratory for Magneto-Photoelectrical Composite and Interface Science, School of Mathematics and Physics, University of Science and Technology Beijing, Beijing 100083, China.
Soft Matter. 2017 Oct 11;13(39):7034-7045. doi: 10.1039/c7sm01001j.
The vertical, horizontal, and three-dimensional (3D) distribution of binary particles with different diameters are investigated simultaneously in a cylindrical container under coupling vibration and airflow. Airflow is blown into the vertically vibrating granular bed from its bottom with vibration frequency of f = 15, 30, and 45 Hz; vibration acceleration Γ = 2-7; and air velocity u = 0-1.82 m s (fluidization number u/u = 0-1.49). In our experiments, several distribution states have been observed, such as the mixing state, where particles are uniformly mixed; Brazil nut separation (BN), where large particles rise to the top; reverse Brazil nut separation (RBN), where large particles sink to the bottom; horizontal separation (HS), where binary particles separate horizontally; and combined distribution of BN/RBN and HS, in which one type of particles is above the other and close to one side of the container wall. Briefly, the vertical distribution forms five pattern types, and the horizontal distribution has four pattern types. The resultant pattern of 3D distribution exhibits 15 pattern types. These patterns can be always obtained under the conditions of certain control parameters, but the condition differs with the diameter ratio of binary particles. Phase diagrams of vertical, horizontal, and 3D distributions are drawn to provide the excitation condition of various patterns. These experimental results contribute to the further understanding of the entire distribution of particles and the control of particle distribution for different industry requirements.
在耦合振动和气流的作用下，研究了圆柱形容器中不同粒径的二元颗粒的垂直、水平和三维（3D）分布。气流以振动频率 f = 15、30 和 45 Hz；振动加速度 Γ = 2-7；和空气速度 u = 0-1.82 m s（流化数 u/u = 0-1.49）从底部吹入垂直振动的颗粒床。在我们的实验中，观察到了几种分布状态，如混合状态，其中颗粒均匀混合；巴西坚果分离（BN），其中大颗粒上升到顶部；反向巴西坚果分离（RBN），其中大颗粒下沉到底部；水平分离（HS），其中二元颗粒水平分离；以及 BN/RBN 和 HS 的组合分布，其中一种类型的颗粒位于另一种类型的颗粒上方并靠近容器壁的一侧。简而言之，垂直分布形成了五种图案类型，水平分布有四种图案类型。3D 分布的结果呈现出 15 种图案类型。这些图案可以在一定控制参数的条件下始终获得，但条件随二元颗粒的直径比而不同。绘制了垂直、水平和 3D 分布的相图，以提供各种图案的激励条件。这些实验结果有助于进一步了解颗粒的整体分布和不同工业要求下的颗粒分布控制。
