Research Papers: Multiphase Flows

Modeling of Axial-Symmetric Flow Structure in Gas–Solids Risers

[+] Author and Article Information
Pengfei He

Department of Mechanical
and Industrial Engineering,
New Jersey Institute of Technology,
Newark, NJ 07102
e-mail: ph36@njit.edu

Dawei Wang

Department of Mechanical
and Industrial Engineering,
New Jersey Institute of Technology,
Newark, NJ 07102
e-mail: dw56@njit.edu

Rajesh Patel

Department of Mechanical
and Industrial Engineering,
New Jersey Institute of Technology,
Newark, NJ 07102
e-mail: rsp25@njit.edu

Chao Zhu

Department of Mechanical
and Industrial Engineering,
New Jersey Institute of Technology,
Newark, NJ 07102
e-mail: chao.zhu@njit.edu

1Present address: Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, OH, 43210.

2Present address: Department of Mechanical Engineering, Pandit Deendayal Petroleum University, Raisan, Gujarat 382007, India.

3Corresponding author.

Contributed by the Fluids Engineering Division of ASME for publication in the JOURNAL OF FLUIDS ENGINEERING. Manuscript received December 15, 2014; final manuscript received August 18, 2015; published online December 8, 2015. Assoc. Editor: E. E. Michaelides.

J. Fluids Eng 138(4), 041302 (Dec 08, 2015) (8 pages) Paper No: FE-14-1753; doi: 10.1115/1.4031686 History: Received December 15, 2014; Revised August 18, 2015

Pneumatic transport of solids in a riser has a unique nonuniform flow structure, characterized by the core solids acceleration and the wall solids deceleration along the riser, which causes the down-flow of solids and hence back mixing. To predict this nonuniform flow structure, this paper presents a mechanistic model that includes two controlling mechanisms: the interparticle collision damping for axial transport of solids and the effects of collision-induced diffusion and turbulent convection for radial transport of solids. The model predictions are partially validated against available measurements, such as axial and radial distributions of concentration and velocity of solids.

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Fig. 1

Schematic representation of riser flow structure with radial transport mechanism

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Fig. 2

Parabolic fitting of radial profile of solid velocity data

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Fig. 3

Parabolic fitting on radial profile of solid volume fraction data

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Fig. 4

Axial profile of solid velocity against the data by Parssinen and Zhu [3]

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Fig. 5

Radial profile of solid velocity against the data by Parssinen and Zhu [3]

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Fig. 6

Cross-sectional averaged solid velocity verses solid volume fraction

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Fig. 7

Axial profile of pressure and gas density

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Fig. 8

Axial profile of solid volume fraction

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Fig. 9

Radial profile of solid volume fraction

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Fig. 10

Axial profile of gas velocity

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Fig. 11

Radial profile of gas velocity

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Fig. 12

Radial profile of solid velocity



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