Evaluation on the Accuracy of an Inline Image-Based Method for Regular and Irregular Particles

Abstract

Although the image-based method is considered to be the most direct and accurate measurement method compared to some other methods, there are some factors that add uncertainties to the measurements. In this study, a newly developed inline image-based method consisting of a telecentric vision probe and automatic particle identification software is evaluated by comparing with other recognized measuring technologies for regular and irregular particles. The subject technique provides pretty good repeatability for both regular (σ D 50 = 0.65%) and irregular particles (σ D 50 = 1.26%). From an engineering perspective, the measurement results of average diameters reveal the reliability of this image-based method. The maximum relative deviations are respectively 6.56% and 3.90% compared to the laser diffraction. Future work should be devoted to further improvement of the accuracy of this image-based method including contour identification, the particle shape-based reconstruction models, and the 3D image techniques based on binocular or multiple vision probes.

Veiling Effects in the Measurement of Poly-disperse Particles with a Photographic Probe

“…Under every experimental condition, 500 sampling images (corresponding to more than 24 s) are taken at a measuring point. An automatic particle identification procedure developed previously combined with manual correction is applied to recognize the in-focus particles. Then, the particle diameter is calculated by the equivalent diameter method .…”

Multivision Probe Combination Measurement for Polydisperse Particles in Multiphase Reactors

“…Under every experimental condition, 500 sampling images (corresponding to more than 24 s) are taken at a measuring point to ensure statistical stability. Detailed image processing can be referred to ref , and here, the basic steps are described briefly: (1) An automatic particle identification procedure developed previously combined with manual correction is applied to recognize the in-focus particles; (2) the particle diameter is calculated by the equivalent diameter method (EDM); and (3) the calculation of particle holdup can refer to Wang et al…”

Polydisperse particle inline image method and its application onto gas–liquid flow in a stirred tank

“…24 Photographic techniques are becoming more and more popular as they record the multiphase flow directly and thought as the most intuitive and high-fidelity techniques. 25 Non-invasive optical photography combined with particle tracking velocimetry are frequently employed to determine the bubble velocity. 26,27 However, significant errors may be incurred in cases involving overlays of polydisperse bubbles rising at different velocities or large deformable bubbles.…”

“…Photographic techniques are becoming more and more popular as they record the multiphase flow directly and thought as the most intuitive and high‐fidelity techniques 25 . Non‐invasive optical photography combined with particle tracking velocimetry are frequently employed to determine the bubble velocity 26,27 .…”