Flow characterization of high-pressure dense-phase pneumatic conveying of coal powder is not fully understood. To further reveal the dynamic behavior of coal particles in dense-phase pneumatic conveying pipelines, a method for the scale decomposition of particle motion based on empirical mode decomposition and Hurst analysis of experimental electrostatic signals is reported. This allows the multi-scale motion characteristics of single coal particles and particle clusters to be determined. Micro-, meso-, and macro-scale subsets were reconstructed, which reflected the different behaviors of the coal particles: specifically, dynamic features of the micro-scale subset represented features of single particle collisions and frictional interactions; dual fractal characteristics of the meso-scale subset described the motion of coal particle clusters; and features of the macro-scale subset reflected persistent dynamic behavior of the entire pneumatic conveying system. Motion behavior of single particles and particle clusters could be respectively investigated by considering the relative energies of the micro- and meso-scale contributions to the electrostatic signal. This was verified both by theoretical analysis and experiment.

煤粉的高压密相气力输送的流动特性尚未完全了解。为了进一步揭示密相气力输送管道中煤颗粒的动力学行为，报道了一种基于经验模态分解和实验静电信号的赫斯特分析的颗粒运动的尺度分解方法。这使得可以确定单个煤颗粒和颗粒簇的多尺度运动特性。重建了微观，中观和宏观子集，这反映了煤颗粒的不同行为：具体而言，微观子集的动态特征代表了单个颗粒碰撞和摩擦相互作用的特征。中尺度子集的双重分形特征描述了煤颗粒团簇的运动。宏观子集的特征和特征反映了整个气动输送系统的持续动态行为。通过考虑微尺度和介观尺度对静电信号贡献的相对能量，可以分别研究单个粒子和粒子团的运动行为。理论分析和实验均证实了这一点。