Many industrial processes use bins for storage of granular particles. However, the discharge of granular particles through bins is not well described quantitatively. Monitoring and analysis of the flow of particles inside bins is a challenge faced in many industrial operations. Understanding particle flow during discharge can lead to significant improvements in the design and construction of bins. The paper presents a technique to detect the particle flow pattern inside a silo using X-ray radiography. The particle flow patterns for a mass-flow bin and a funnel-flow bin were detected by the in-situ tracking of tagged granular particles during discharge. X-ray radiographs of the silo were obtained at different times of discharge, which were then analyzed using image processing techniques, and the tagged particles in the silo were tracked. The individual particle trajectories obtained explain the particle flow pattern in the silo. (C) 2018 Elsevier B.V. All rights reserved.