Study of Flow Behavior of Granular Material Inside Cylindrical Silo Using Ultrafast X-Ray Imaging Technique

Abstract

This paper presents an application of an ultrafast electron beam X-ray CT scanner for investigating the gravitational flow behavior of granulates through cylindrical silo model. The CT scanner allows obtaining crosssectional images of the granular material distribution with a spatial resolution of approximately 1 mm and a time resolution of 2 kHz. In order to conduct a deep analysis of the granular flow concentration changes, two image processing algorithm steps were applied. The first step deals with preprocessing and re-centering stacks of raw images. The second step divides the preprocessed image into several concentric rings and calculates the mean value to study radial concentration changes. Independent analysis of granular concentration in each ring provides useful knowledge to study the silo discharging during mass flow and funnel flow.

A new data-processing approach to study particle motion using ultrafast X-ray tomography scanner: case study of gravitational mass flow

“…The previous analyses of this study have shown that the concentration of particles slightly decreases as the scanning position change from top to bottom position (around 3% changes between measurements at 800 and 500 mm) (Waktola et al 2016). This is also in line with the fact that particle velocity tends to increase as the particles flow down (see Table 1).…”

“…The previous investigation of this study has shown that the flow analysis inside the silo model was characterized by a quasi-steady flow and particles did not change their position within few milliseconds (Waktola et al 2016). As a result, each tracer particle can be segmented individually within its own bounding area, which also helps to apply different local threshold value depending on the brightness level of the particles.…”