In-line imaging measurements of particle size, velocity and concentration in a particulate two-phase flow--颗粒学报PARTICUOLOGY

Chen, X., Zhou, W., Cai, X., Su, M., & Liu, H. (2014). In-line imaging measurements of particle size, velocity and concentration in a particulate two-phase flow. Particuology, 13, 106–113. https://doi.org/10.1016/j.partic.2013.03.005

Xiaozhen Chen, Wu Zhou^*, Xiaoshu Cai, Mingxu Su, Hailong Liu

Institute of Particle and Two-phase Flow Measurement, University of Shanghai for Science and Technology, Shanghai 200093, China

10.1016/j.partic.2013.03.005

Volume 13, April 2014, Pages 106-113

Received 18 October 2012, Revised 9 March 2013, Accepted 29 March 2013, Available online 25 June 2013.

E-mail: usst_wzhou@163.com

Highlights

• An image method was developed for in-line measurements of dilute two-phase flow.

• Different brightness of the background needs different threshold calculation methods.

• The method is capable of simultaneously measuring particle size, velocity and concentration.

Abstract

A novel method is developed for in-line measurements of particle size, velocity and concentration in a dilute, particulate two-phase flow based on trajectory image processing. The measurement system consists of a common industrial CCD camera, an inexpensive LED light and a telecentric lens. In this work, the image pre-processing steps include stitching, illumination correction, binarization, denoising, and the elimination of unreal and defocused particles. A top-hat transformation is found to be very effective for the binarization of images with non-uniform background illumination. Particle trajectories measured within a certain exposure time are used to directly obtain particle size and velocity. The particle concentration is calculated by using the statistics of recognized particles within the field of view. We validate our method by analyzing experiments in a gas-droplet cyclone separator. This in-line image processing method can significantly reduce the measurement cost and avoid the data inversion process involved in the light scattering method.

Graphical abstract

Keywords

In-line measurements; Particle trajectory; Image processing; Multi-parameters

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