International Society for Industrial Process Tomography

Identification of the gas/solid Two­Phase Flow

Regime based on Electrostatic Sensor and HHT

Jun Dong1, Hongli Hu1*, Juan Zhang1, Qinxing Zhao2 and Qulan Zhou 2

1. State Key Laboratory of Electrical Insulation for Power Equipment, Xi’an Jiao tong University,
   Xi’an710049, China

   
   

2. State Key Laboratory of Multi­phase Flow for Power Engineering, Xi’an Jiao tong University,
   Xi’an710049, China

Abstract – ­­In the gas/solid two­phase system, particles can accumulate a large number of electrostatic charges because of the collision, friction and separation between particles or between particles and wall. When particles moving through in the electrostatic sensor, the sensor induces fluctuated signal because of the constantly fluctuation of the quasi­electrostatic filed around the sensors. Through the detection and processing of the induced fluctuated charge signal, measuring system can obtain two­phase flow parameters, such as concentration, flow regime. This paper used electrostatic sensor to measure the moving electric charges carried by solid particles in pipelines of pneumatic transport. And a microcomputer and NI PCI 6024­based measuring system has been built on the basis of the method for measuring the electric charges of solid particles. Then the Hilbert–Huang transform (HHT) was used to process the fluctuation signal generated induced by the electrostatic sensor. The result show that marginal Hilbert spectrum of the electrostatic signal can be used to identify the gas­solid flow regime.

Key word: HHT, electrostatic sensor, flow regime, gas/solid two­phase flow.