Single-photon emission radioactive particle tracking method for hydrodynamic evaluation of multi-phase flows (Open Access)--颗粒学报PARTICUOLOGY

van der Sande, P. C., de Mooij, J., Wagner, E. C., Meesters, G. M. H., & van Ommen, J. R. (2025). Single-photon emission radioactive particle tracking method for hydrodynamic evaluation of multi-phase flows. Particuology, 101, 43-56. https://doi.org/10.1016/j.partic.2023.10.001

Single-photon emission radioactive particle tracking method for hydrodynamic evaluation of multi-phase flows (Open Access)

P. Christian van der Sande^*, Jack de Mooij, Evert C. Wagner, Gabrie M.H. Meesters, J. Ruud van Ommen^*

Department of Chemical Engineering, Delft University of Technology, Van der Maasweg 9, Delft 2629HZ, The Netherlands

10.1016/j.partic.2023.10.001

Volume 101, June 2025, Pages 43-56

Received 10 July 2023, Revised 6 October 2023, Accepted 7 October 2023, Available online 26 October 2023, Version of Record 29 May 2025.

E-mail: P.C.vanderSande@tudelft.nl; J.R.vanOmmen@tudelft.nl

Highlights

• A novel radioactive particle tracking method to evaluate hydrodynamics of multi-phase flow systems is introduced.

• Static and dynamic validation of the method demonstrate reconstruction with 1 mm spatial accuracy and precision.

• The method is used to study the solids flow field in a laboratory-scale horizontal stirred bed reactor.

Abstract

Evaluation of the hydrodynamics of opaque multi-phase flows remains a challenging task, with implications for various industrial processes such as chemical processing, pharmaceutical, and mineral processing. Understanding how design and operational variables affect the complex behavior of multi-phase flow systems is essential for optimizing processing conditions and improving efficiency. Radioactive particle tracking (RPT) has been a proven measurement technique to evaluate hydrodynamics in multi-phase flow systems. However, a limitation of the classical RPT technique exists in the assumptions made in the simulation of the count rate received by the detectors in correcting for varying flow-induced fluctuations in the volume fraction of the dispersed phase, often encountered in industrial multi-phase flow systems.

In this paper, we introduce a fundamentally novel experimental RPT method that directly uses detected incident photon hit locations for the reconstruction of the three-dimensional radioactive tracer particle position. We argue that this approach is inherently more robust as varying attenuation does not affect the reconstruction. The RPT setup consists of three identical γ-radiation slit collimator detectors that are placed equidistantly at 120° intervals. A subsequent calibration-experimentation procedure is established that allows reconstruction of the tracer particle position with spatial accuracy and precision in the order of 1 mm. We demonstrate the applications of this technique in evaluating hydrodynamics in multi-phase systems by characterizing the flow field of industrial-grade polypropylene reactor powder in a laboratory-scale horizontal stirred bed reactor.

Graphical abstract

Keywords

Radioactive particle tracking; Granular flows; Hydrodynamics; Non-invasive monitoring; Horizontal stirred bed reactors

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