Signal analysis of electrostatic gas-solid two-phase flow probe with Hilbert-Huang transform

Ring-shaped electrostatic gas-solid two-phase flow probe can provide mechanical parameters of the pneumatically transported powders, and has been used for measuring and controlling the pulverized coal flow distribution among conveyors leading to burners in coal-fired power stations. But the signal obtained from the probe demonstrates strongly non-linear characteristic. In this paper, efforts had been paid to investigate the signal by means of Hilbert-Huang transform, including the empirical mode decomposition (EMD) and Hilbert spectral analysis (HAS) on the signal of the probe. The EMD results unveiled that low-frequency oscillation existed and its amplitude was non-decayed. HAS interpreted the EMD results by time-frequency joint analysis and described the instantaneous behavior of gas-solid two-phase flow.