(752d) Prediction of Solid Flow Rate during the Conveying Process Based on the Generation Mechanism of Acoustic Emission Signals

Peng Zhang^a, Tao Sheng^a, Hanqing Wang^b, Yao Yang^{a, c, *}

^a Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310027, P.R. China

^b Hangzhou No.14 High School, Hangzhou 310006, P.R. China

^c Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou 310027, P.R. China

* Corresponding author: Yao Yang, E-mail: yangyao306@gmail.com

It has been proved that in multiphase flow processes such as hydraulic conveying and fluidized bed, the acoustic emission signals generated by particle motions can be detected and analyzed to realize the measurement of particle size and solid mass flow rate, identification of flow regime, and fault diagnosis. However, these models are often obtained through data regression, the physical meaning of which is not clear enough. As a result, the universality of these models is bad. Therefore, this work aims to establish a predictive model of particle mass flow rate during the particle conveying process with the generation mechanism of acoustic emission signals. This method is supposed to have better university due to the clear physical meaning. The whole work is conducted as follows. Firstly, single particle-wall collision experiments are conducted to explore generation mechanism of acoustic emission signals. Results show that the intensity of the acoustic emission signals during the single particle collision is linearly related to the particle mass and particle-wall collision velocity. Then, combined with the existing homogeneous particle group-wall collision frequency model, an acoustic energy model is proposed for the homogeneous particle group-wall interaction. For the hydraulic conveying process where the particle motions were homogeneous, this model showed good prediction accuracy and universality. But for the riser with complex particle motions (particle back mixing), the model has a low accuracy since the generation of acoustic signals is so complex that it is far from the homogeneous particle group-wall collision. However, with a self-designed screened-waveguide by which the generation of acoustic emission signals is simplified into single particle-probe collision, the particle mass flow rate was also accurately predicted using the acoustic energy model.

Keywords: solid flow rate, particle-wall collision, acoustic emission detection, hydraulic conveying, riser