The minimum conveying velocity or the lowest point of pressure drop curve can reflect the characteristics of particles moving from deposition to suspension in pneumatic conveying. However, when the mass flow rate is low, the change of particles flow cannot be effectively reflected by the above methods. In this paper, based on a 4-arc electrode electrostatic sensor, with localised sensitivity, the detailed scale signals that represent the particle random motion are extracted by the combination of Empirical Mode Decomposition (EMD) and Hurst exponent. The differences in the particle random motion energy ratio (PRMER) of 4-channel electrode signals are used to characterize the transition of flow state. In the verification experiment by using a belt-style electrostatic velocity measured rig, the higher the velocity of rubber belt or the closer to the electrode, the higher the PRMERs of electrostatic signal. In the experiment of gas-solid two-phase flow rig, the PRMERs of 4-channel electrode signals are all increasing with the increase of superficial gas velocity, and the PRMERs of different electrodes are rather different at low superficial gas velocity ( ${V}_{g}$ ). When ${V}_{g}$ drops at the minimum pressure drop point ( ${P}_{{MPD}}$ ), the PRMERs of top/bottom and left/right electrodes begin to separate (e.g. the particle mass flow rates are 100 kg/h and 120 kg/h). Furthermore, when the solid mass flow rate is 80 kg/h, the proposed method can clearly characterize the transition of flow states in the pipeline, but the pressure drop phase diagram cannot.

中文翻译：

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用于确定气力输送中颗粒从沉积到悬浮的特性的静电传感器

最小输送速度或压降曲线的最低点可以反映气力输送中颗粒从沉积到悬浮的运动特性。然而，当质量流量较低时，上述方法不能有效反映颗粒流量的变化。在本文中，基于4弧电极静电传感器，具有局部灵敏度，通过经验模式分解（EMD）和Hurst指数的组合提取代表粒子随机运动的详细尺度信号。4通道电极信号的粒子随机运动能量比（PRMER）的差异被用来表征流动状态的转变。在采用带式静电测速装置的验证实验中，橡胶带的速度越高或离电极越近，静电信号的 PRMER 就越高。在气固两相流实验中，4通道电极信号的PRMERs都随着表观气速的增加而增加，而在低表观气速下不同电极的PRMERs差异较大（ ${V}_{g}$ ）。什么时候 ${V}_{g}$ 在最小压降点（ ${P}_{{MPD}}$ )，上/下和左/右电极的 PRMER 开始分离（例如，颗粒质量流速为 100 kg/h 和 120 kg/h）。此外，当固体质量流量为 80 kg/h 时，所提出的方法可以清楚地表征管道中流动状态的转变，而压降相图则不能。