scholarly journals Numerical analysis and optimization of key parts in the stirred tank based on solid-liquid flow field

2022 ◽  
Vol 105 (1) ◽  
pp. 003685042110672
Author(s):  
Hongwan Jiang ◽  
Sen Yuan ◽  
Hao Liu ◽  
Weiwei Li ◽  
Xiaorong Zhou
Keyword(s):  
Flow Field ◽  
Particle Concentration ◽  
Flow Model ◽  
Particle Distribution ◽  
Dead Zone ◽  
Clear Liquid ◽  
Mixing Performance ◽  
Liquid Suspension ◽  
Solid Liquid ◽  
Multiple Reference

In order to further improve the mixing performance of the mixing device, the structure of the agitator was optimized, and the effects of the diameter and pitch of the agitator on the solid-liquid suspension characteristics were analyzed by single factor method. Multiple reference frame (MRF), computational fluid dynamics, Euler multiphase flow model and standard K- ε turbulence model were used to investigate the effect of the height from the bottom of the agitator on the suspension characteristics of particles in the agitator was studied. The results show that reducing the height from the bottom of the agitator can promote the suspension of particles at the bottom of the tank, but too low height from the bottom will easily produce mixing dead zone at the bottom of the tank, and cause the accumulation of particles. Reducing the height of the agitator from the bottom will enlarge the clear liquid area of the flow field, cause uneven particle distribution and increase the stirring torque. With the increase of agitator diameter, the critical suspension speed of the flow field decrease, but the stirring power required by the flow field increase. Increasing the blade spacing in a certain range can promote the suspension of particles and make the distribution of particles in the flow field more uniform. Therefore, the mixing power and the uniformity of particle concentration distribution need to be considered together in order to make the mixing device more efficient and energy-saving.

Nuclear Magnetiic Resonance Imaging (NMRI) of Flow-Induced Microstructure of Concentratied Suspensions

1992 ◽  
Vol 289 ◽  
Author(s):  
A. W. Chow ◽  
S. W. Sinton ◽  
J. H. Iwamiya
Keyword(s):  
Particle Concentration ◽  
Particle Distribution ◽  
Leading Edge ◽  
Particle Migration ◽  
Fall Velocity ◽  
Resonance Flow ◽  
Liquid Suspensions ◽  
Induced Changes ◽  
Solid Liquid ◽  
Neutrally Buoyant

AbstractThe application of nuclear magnetic resonance flow imaging (NMRI) to the study of Couette and falling-ball viscometry of solid/liquid suspensions is described. The suspension consisted of non-Brownian, monodisperse, neutrally-buoyant spheres of 50 vol%. NMRI data demonstrated flow-induced changes in the particle distribution in the suspension that strongly influence the accuracy in viscosity measurements using these flow geometries. In Couette flow, direct correlation between stress measurements and particle concentrations at various locations in the flow cell as a function of shear strain can be made. Our data directly confitrm the shearinduced particle migration theory proposed by Leighton and Acrivos.[1] In the falling-ball experiments, increased particle concentration at the leading edge and decreased concentration at the trailing edge of the ball was observed when the falling ball is big compared to the cylinder containing the suspension. This change in particle distribution can be directly related to the changes in fall velocity of the ball as a function of position in the cylinder.

scholarly journals Optimizing the cleanliness in multi-segment disk amplifiers based on vector flow schemes

2018 ◽  
Vol 6 ◽  
Author(s):  
Zhiyuan Ren ◽  
Jianqiang Zhu ◽  
Zhigang Liu ◽  
Xiaowei Yang
Keyword(s):  
Flow Field ◽  
Particle Concentration ◽  
Flow Model ◽  
Three Dimensional ◽  
Phase Flow ◽  
Three Dimensional Flow ◽  
Two Phase ◽  
Key Factor ◽  
Measurement Experiment ◽  
Laser Induced Damage

The objective of maintaining the cleanliness of the multi-segment disk amplifier in Shenguang-II (SG-II) is to reduce laser-induced damage for optics. The flow field of clean gas, which is used for the transportation of contaminant particles, is a key factor affecting the cleanliness level in the multi-segment disk amplifier. We developed a gas–solid coupling and three-dimensional flow numerical simulation model. The three-dimensional and two-phase flow model is verified by the flow-field smog experiment and the particle concentration measurement experiment with the 130-disk amplifier in SG-II. By optimizing the boundary conditions with the same flow rate, the multi-inlet vector flow scheme can not only effectively reduce the purging time, but also prevent the reverse diffusion of contaminant particles in the multi-segment disk amplifier and the deposition of contaminant particles on the surface of the Nd:glass.

Numerical Simulation for Solid-Liquid Two-Phase Flow in Stirred Vanadium Leaching Tank

2013 ◽  
Vol 456 ◽  
pp. 314-319
Author(s):  
Jian Yi Kong ◽  
Zong Wu Wu ◽  
Yu Hou ◽  
Xing Dong Wang
Keyword(s):  
Flow Field ◽  
Reference Value ◽  
Reaction Vessel ◽  
Two Phase ◽  
Mixing Effect ◽  
Vanadium Extraction ◽  
Computational Fluid Dynamics Cfd ◽  
Frame Method ◽  
Solid Liquid ◽  
Multiple Reference

The flow field in the leaching tank for the vanadium extraction in the stone coal was simulated by the Computational Fluid Dynamics (CFD) software. The flow field physical model was established by GAMBIT and the agitating area was processed by k-ε turbulence model and multiple reference frame method. The mixing effect was discussed under the two conditions: (1) Double impellers rotate in the same direction. (2) Double impellers rotate in different directions. The result shows that the mixing effect of the double impellers which rotate in different directions is better under the same condition. Its distribution of the turbulent kinetic energy is more reasonable, and it can ease the sediment at the bottom. The simulation results have certain reference value for the research of the law of the inner flow field so as to optimize its structure in the stirred reaction vessel.

SIMULATION OF SOLID–LIQUID SUSPENSION AND SCALE-UP OF AGAROSE GEL ACTIVATION REACTOR

2016 ◽  
Vol 16 (06) ◽  
pp. 1650087
Author(s):  
XUELING ZHOU ◽  
YIFAN LIU ◽  
WEN YU ◽  
SHAOJIE CHENG ◽  
JIANZHONG YIN
Keyword(s):  
Flow Model ◽  
Allyl Bromide ◽  
Scale Up ◽  
Structure Design ◽  
Agarose Gel ◽  
Activated Alumina ◽  
Stirred Reactor ◽  
Liquid Suspension ◽  
Solid Suspension ◽  
Solid Liquid

Agarose gel activation reaction, which is of great importance in preparing the carrier of the column packing material for blood purification, would be significantly influenced by the configuration and parameter of reactor. In order to optimize the structure design of the reactor and operating parameters of the process, the characteristics of suspension system composed of agarose gel, NaOH, water, 3-allyl bromide, and activated alumina were simulated numerically utilizing an Eulerian multiphase flow model and multi-reference frame (MRF) approach. The effect of impeller configuration was studied with three typical impellers, including Rushton disk turbine (DT), pitched blade downflow turbine (PBTD45), and pitched blade upflow turbine (PBTU45). The results showed that the optimum solid suspension was obtained using PBTD45 impeller with a diameter of 100[Formula: see text]mm and critical suspension speed of 570[Formula: see text]rpm in a 20[Formula: see text]L stirred reactor. In addition, the critical suspension speeds using the three impellers were calculated and the errors were all within the engineering allowance. Finally, the feasibility of scale-up design for agarose gel activation reactor was preliminarily discussed. The results would be useful to the optimization and scale-up of relevant reactor design.

scholarly journals Solid-Liquid Mixing In Agitated Tanks : Experimental And CFD Analysis

2021 ◽  
Author(s):  
Seyed. Hosseini
Keyword(s):  
Suspension Polymerization ◽  
Fluid Dynamic ◽  
Impeller Speed ◽  
Cfd Analysis ◽  
Mixing Performance ◽  
Solid Density ◽  
Liquid Mixing ◽  
Solid Liquid ◽  
Multiple Reference ◽  
Good Agreement

Solid-liquid mixing plays a significant role in crystallization, suspension polymerization, leaching, solid-catalyzed reaction and adsorption. In this study, a computational fluid dynamic (CFD) model was developed for solid-liquid mixing in a cylindrical tank equipped with a top-entering impeller. The multiple reference frame (MRF) technique, k-ε model and Eulerian-Eulerian approach were employed to simulate the impeller rotation, turbulent flow and multiphase flow, respectively. The effects of impeller speed, solid concentration, particle size, solid density and impeller clearance on the mixing performance of four different impellers (A310, marine propeller, pitched blad turbine and A320) were investigated. The CFD results were in good agreement with experimental data measured using electrical resistance tomography (ERT). In order to investigate the mixing quality in this study, the impeller speed required for maximum homogeneity, clouding height, and just-suspended impeller speed were investigated.

scholarly journals Solid-Liquid Mixing In Agitated Tanks : Experimental And CFD Analysis

2021 ◽  
Author(s):  
Seyed. Hosseini
Keyword(s):  
Suspension Polymerization ◽  
Fluid Dynamic ◽  
Impeller Speed ◽  
Cfd Analysis ◽  
Mixing Performance ◽  
Solid Density ◽  
Liquid Mixing ◽  
Solid Liquid ◽  
Multiple Reference ◽  
Good Agreement

Solid-liquid mixing plays a significant role in crystallization, suspension polymerization, leaching, solid-catalyzed reaction and adsorption. In this study, a computational fluid dynamic (CFD) model was developed for solid-liquid mixing in a cylindrical tank equipped with a top-entering impeller. The multiple reference frame (MRF) technique, k-ε model and Eulerian-Eulerian approach were employed to simulate the impeller rotation, turbulent flow and multiphase flow, respectively. The effects of impeller speed, solid concentration, particle size, solid density and impeller clearance on the mixing performance of four different impellers (A310, marine propeller, pitched blad turbine and A320) were investigated. The CFD results were in good agreement with experimental data measured using electrical resistance tomography (ERT). In order to investigate the mixing quality in this study, the impeller speed required for maximum homogeneity, clouding height, and just-suspended impeller speed were investigated.

Status of Advanced Two-Phase Flow Model Development for SRM Chamber Flow Field and Combustion Modeling

2004 ◽  
Author(s):  
Gary Luke ◽  
Mark Eagar ◽  
Michael Sears ◽  
Scott Felt ◽  
Bob Prozan
Keyword(s):  
Flow Field ◽  
Flow Model ◽  
Two Phase Flow ◽  
Model Development ◽  
Phase Flow ◽  
Two Phase ◽  
Combustion Modeling

scholarly journals Mathematical modeling and experimental study on solid–liquid suspension separation in ultrasonic standing wave field

2021 ◽  
pp. 146134842110229
Author(s):  
Yajing Wang ◽  
Liqun Wu ◽  
Yaxing Wang ◽  
Yafei Fan
Keyword(s):  
Standing Wave ◽  
Sound Pressure ◽  
Acoustic Radiation ◽  
Sound Field ◽  
Radiation Force ◽  
High Energy ◽  
Factors Affecting ◽  
Liquid Suspension ◽  
Ultrasonic Standing Wave ◽  
Solid Liquid

A new method of removing waste chips is proposed by focusing on the key factors affecting the processing quality and efficiency of high energy beams. Firstly, a mathematical model has been established to provide the theoretical basis for the separation of solid–liquid suspension under ultrasonic standing wave. Secondly, the distribution of sound field with and without droplet has been simulated. Thirdly, the deformation and movement of droplets are simulated and tested. It is found that the sound pressure around the droplet is greater than the sound pressure in the droplet, which can promote the separation of droplets and provide theoretical support for the ultrasonic suspension separation of droplet; under the interaction of acoustic radiation force, surface tension, adhesion, and static pressure, the droplet is deformed so that the gas fluid around the droplet is concentrated in the center to achieve droplet separation, and the droplet just as a flat ball with a central sag is stably suspended in the acoustic wave node.

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