Open Access

ARTICLE

Numerical Simulation of the Mixing and Hydrodynamics of Asphalt and Rubber in a Stirred Tank

Zechen Yao¹, Renfeng Yang^1,*, Haichao An²

1 School of Construction Machinery, Chang’an University, Xi’an, 710064, China
2 School of Transportation and Logistics, Taiyuan University of Science and Technology, Taiyuan, 030024, China

* Corresponding Author: Renfeng Yang. Email:

Fluid Dynamics & Materials Processing 2021, 17(2), 397-412. https://doi.org/10.32604/fdmp.2021.012114

Received 15 July 2020; Accepted 24 December 2020; Issue published 02 April 2021

Abstract

Computational fluid dynamics (CFD) has been used to analyze the mixing process of Asphalt and Rubber (AR) in a stirred tank with a six flat-blade disc turbine (Rushton), a down-pumping 45° pitched-blade turbine (PBTD-6) and a down-pumping propeller (TXL). The two-phase (solid-liquid) flow in the considered stirred tank has been modelled in the framework of an Eulerian-Eulerian approach, a laminar-flow assumption and a multi-reference frame strategy. The following effects have been investigated: The influence of the impeller speed, impeller type, crumb rubber (CR) particle diameter and initial CR particle loading on the quality of the CR particle’s suspension. The outcomes of the numerical simulations have been found to be in good agreement with the experimental results. The most important findings can be summarized as follows. The flow velocity on the lower part of the stirred tank, induced by the Rushton impeller, is the highest for the three considered mixing systems at the same impeller speed. The suspension quality of CR particles increases with the impeller speed. A larger particle diameter and a higher initial CR particle loading lead to an uneven distribution of particles. The degree of homogeneity in the Rushton impeller system is better than that of the PBTD-6 impeller system and the TXL impeller system at the same impeller speed, while the suspension uniformity of the TXL impeller system is the best possible one for the same power consumption.

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Keywords

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