Modeling evaluation on solid-liquid mixing characteristics in a dislocated guide impeller stirred tank
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Deyin Gu
,
Fenghui Zhao
Abstract
The solid-liquid mixing characteristics in a stirred tank with pitched blade impellers, dislocated impellers, and dislocated guide impellers were investigated through using CFD simulation. The effects of impeller speed, impeller type, aperture ratio, aperture length, solid particle diameter and initial solid holdup on the homogeneity degree in the solid-liquid mixing process were investigated. As expected, the solid particle suspension quality was increased with an increase in impeller speed. The dislocated impeller could reduce the accumulation of solid particles and improve the cloud height compared with pitched blade impeller under the same power consumption. The dislocated guide impeller could enhance the solid particles suspension quality on the basis of dislocated impeller, and the optimum aperture ratio and aperture length of dislocated guide impeller were 12.25% and 7 mm, respectively, in the solid-liquid mixing process. Smaller solid particle diameter and lower initial solid holdup led to higher homogeneity degree of solid-liquid mixing system. The dislocated guide impeller could increase solid particle integrated velocity and enhance turbulent intensity of solid-liquid two-phase compared with pitched blade impeller and dislocated impeller under the same power consumption.
Funding source: Science and Technology Research Project of Chongqing Education Commission
Award Identifier / Grant number: KJQN201900802
Funding source: Scientific Research Projects for High-Level Talents of Chongqing Technology and Business University
Award Identifier / Grant number: 1956006
Funding source: Natural Science Foundation of Chongqing Technology and Business University
Award Identifier / Grant number: 1952041
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Author contributions: Deyin Gu: conceptualization, methodology, software, investigation, formal analysis, supervision, writing-original draft. Fenghui Zhao: writing-review and editing. Xingmin Wang: writing-review and editing. Zuohua Liu: writing - review and editing.
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Research funding: The study was supported by the Science and Technology Research Project of Chongqing Education Commission (KJQN201900802), Scientific Research Projects for High-Level Talents of Chongqing Technology and Business University (1956006), and Natural Science Foundation of Chongqing Technology and Business University (1952041).
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Conflict of interest statement: The authors declare no conflicts of interest regarding this article.
Nomenclature
- H
-
liquid height, m
- T
-
stirred tank diameter, m
- R
-
stirred tank radius, m
- z
-
axial coordinate, m
- r
-
radial coordinate, m
- C h
-
local solid volume fraction at height of h in simulation
- C avg
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average solid volume fraction
- n
-
number of sapling points
- g
-
gravitational acceleration, m/s2
- C ε1, C ε2, C μ
-
parameters in the standard k-ε model
- k
-
turbulent kinetic energy, m2/s2
- F drag
-
drag force, N
- C D
-
drag coefficient
- N
-
impeller speed, s−1
- P
-
power consumption, W
- ξ
-
homogeneity
- ρ l
-
liquid density, kg/m3
- ρ s
-
solid density, kg/m3
- ρ
-
density, kg/m3
- α
-
volume fraction
- α l
-
liquid phase volume fraction
- α s
-
solid phase volume fraction
- ε
-
turbulent energy dissipation rate
- μ
-
viscosity, Pa·s
- μ l
-
liquid phase viscosity, Pa·s
- μ t
-
turbulent viscosity, Pa·s
- μ tl
-
liquid phase turbulent viscosity, Pa·s
- σ k , σ ε
-
k and ε turbulent Prandtl number
- ω
-
quality of the solid-liquid mixing system, kg
- V
-
volume of the solid-liquid mixing system, m3
- V s
-
solid phase volume of the solid-liquid mixing system, m3
- C v
-
local solid volume fraction in experiment
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Articles in the same Issue
- Frontmatter
- Editorial
- Preface: Special issue of “Multiphase Flows in Process Engineering: Recent Experimental, Theoretical and Numerical Developments”
- Special Issue Articles
- Effects of periodic cavitation on steam–water flow regime transition and mixing near steam nozzle exit
- Effects of boundary walls on the properties of settling spheres
- Convective heat transfer in magnetized flow of nanofluids between two rotating parallel disks
- Nonlinear radiative transport of hybrid nanofluids due to moving sheet with entropy generation
- Modeling evaluation on solid-liquid mixing characteristics in a dislocated guide impeller stirred tank
- Experimental and simulation study on mixing time and suspension quality of liquid-solid flow field in stirred reactor with draft tube
- Heat transfer enhancement of hybrid nanofluids over porous cone
- Numerical study of a fractal-like tree node micromixer based on Murray’s law
- Floating particles mixing characteristics in an eccentric stirred tank coupled with dislocated fractal impellers
Articles in the same Issue
- Frontmatter
- Editorial
- Preface: Special issue of “Multiphase Flows in Process Engineering: Recent Experimental, Theoretical and Numerical Developments”
- Special Issue Articles
- Effects of periodic cavitation on steam–water flow regime transition and mixing near steam nozzle exit
- Effects of boundary walls on the properties of settling spheres
- Convective heat transfer in magnetized flow of nanofluids between two rotating parallel disks
- Nonlinear radiative transport of hybrid nanofluids due to moving sheet with entropy generation
- Modeling evaluation on solid-liquid mixing characteristics in a dislocated guide impeller stirred tank
- Experimental and simulation study on mixing time and suspension quality of liquid-solid flow field in stirred reactor with draft tube
- Heat transfer enhancement of hybrid nanofluids over porous cone
- Numerical study of a fractal-like tree node micromixer based on Murray’s law
- Floating particles mixing characteristics in an eccentric stirred tank coupled with dislocated fractal impellers
