Investigation on Flow Field of Cyclone Separator Used in Circulating Fluidized Bed Boiler

2013 ◽  
Vol 807-809 ◽  
pp. 1551-1554
Author(s):  
Bing Guang Gao ◽  
Hai Xia Li ◽  
An Chao Zhang ◽  
Jun Song ◽  
Hao Lu ◽  
...  
Keyword(s):  
Flow Field ◽  
Fluidized Bed ◽  
Vortex Structure ◽  
Circulating Fluidized Bed ◽  
Swirling Flow ◽  
Reynolds Stress Model ◽  
Cyclone Separator ◽  
Stress Model ◽  
Fluent Software ◽  
Simulation Results

The Reynolds stress model (RSM) provided by FLUENT software was applied to study flow field of a cyclone separator used in some circulating fluidized bed. The pressure distribution and velocity distribution was analyzed. The simulation results reveal the strong swirling flow and vortex structure in cyclone separator.

Experimental and numerical study of vortex gripper with a diversion body

2011 ◽  
Vol 226 (6) ◽  
pp. 1526-1534 ◽  
Author(s):  
Q Wu ◽  
Q Ye ◽  
G X Meng
Keyword(s):  
Fluid Dynamics ◽  
Numerical Simulation ◽  
Computational Fluid Dynamics ◽  
Swirling Flow ◽  
Numerical Study ◽  
Reynolds Stress Model ◽  
Stress Model ◽  
Lifting Force ◽  
Handling Device ◽  
Simulation Results

This article introduces a new vortex gripper with a diversion body. Vortex gripper, as a pneumatic non-contact handling device, can generate lifting force to hold a workpiece without any contact. In order to predict the characteristics of this new vortex gripper, including pressure distribution on the upper surface of the workpiece, lifting force, supporting stiffness, and flowrate, a computational fluid dynamics study has been carried out. In the vortex cup, air swirling flow is a complex turbulent one; so Reynolds stress model (RSM) was used to describe internal air swirling flow. In addition, an experiment was carried out to study the characteristics of the vortex gripper. When compared with the experimental results, the reliability of numerical simulation results by RSM was verified. The vortex gripper with a diversion body could generate greater lifting force when compared with those designed by Xin et al. with the same air consumption. Therefore, the efficiency of the vortex gripper is improved.

Numerical Simulation of Gas Flow in a Square Cyclone Separator With Double Inlets

2007 ◽  
Author(s):  
Bin Xiong ◽  
Xiaofeng Lu ◽  
R. S. Amano
Keyword(s):  
Pressure Drop ◽  
Flow Field ◽  
Gas Flow ◽  
Numerical Study ◽  
Reynolds Stress Model ◽  
Cyclone Separator ◽  
Stress Model ◽  
Inlet Velocity ◽  
Vortex Finder ◽  
Flow Changes

This paper presents a numerical study of gas flow in a square cyclone separator with a double inlet. The turbulence of gas flow is computed by the use of the Reynolds stress model. The distribution of the flow field and pressure drop under different constructional details, which include changes of the shape, size and arrangement of the vortex finder are obtained. The computed results in the distributions of pressure in different sections are verified by comparison with those measured. We found that the center of the flow field is nearly on the geometric center of the cyclone. The flow fields show a feature of Rankine eddy, i.e., a strongly swirling region in the central part and a pseudo-free eddy region of weak swirling intensity near the cyclone wall. Local vortex exists at the corners where the flow changes their direction sharply, but it is less chaotic than in the general square cyclone with a single inlet. The flow field away from the outlet of the vortex finder is different from the Rankine eddy. The pressure-drop increases rapidly with the increase of the inlet velocity, and the pressure-drop increases with the decrease of the diameter of vortex finder and the increase of length of the vortex finder. The calculat ed results of this paper provide some guidance for the optimization of the square cyclone separator structure.

Numerical Simulation of Venturi Device in Flue-Gas Circulating Fluidized Bed Desulphurization Tower

2011 ◽  
Vol 356-360 ◽  
pp. 1262-1266
Author(s):  
Shao Hua Li ◽  
Guang Cai Qi ◽  
Gui Xia Tang ◽  
Hu Wang
Keyword(s):  
Flow Field ◽  
Fluidized Bed ◽  
Turbulence Intensity ◽  
Flue Gas ◽  
Pressure Loss ◽  
Circulating Fluidized Bed ◽  
Simple Algorithm ◽  
Venturi Tube ◽  
Euler Model ◽  
Fluent Software

Venturi device has important effect on pressure loss and flow field of flue-gas circulating fluidized bed desulphurization tower. Desulfurization tower is huge. Experimental study is difficult and costly. For these problems, PC-SIMPLE algorithm of Euler model of Fluent software is applied and flow condition of four different kinds Venturi tube are simulated in this paper. The pressure loss of curved Venturi is minimum. Three groups of Venturi tube can get uniform velocity field in the tower. Turbulence intensity of a group Venturi tube is maximum, followed by curved Venturi tube. But the turbulence intensity gradient of a group Venturi tube inside the absorber is also the largest. In order to get low pressure loss and better flow field, three groups Venturi tube is optimum.

scholarly journals Optimization of the Turbulence Model on Numerical Simulations of Flow Field within a Hydrocyclone

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Yan Xu ◽  
Zunce Wang ◽  
Lin Ke ◽  
Sen Li ◽  
Jinglong Zhang
Keyword(s):  
Flow Field ◽  
Large Eddy Simulation ◽  
Cross Sections ◽  
Three Dimensional ◽  
Reynolds Stress Model ◽  
Computational Grids ◽  
Test Results ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Simulation Results

Reynolds Stress Model and Large Eddy Simulation are used to respectively perform numerical simulation for the flow field of a hydrocyclone. The three-dimensional hexahedral computational grids were generated. Turbulence intensity, vorticity, and the velocity distribution of different cross sections were gained. The velocity simulation results were compared with the LDV test results, and the results indicated that Large Eddy Simulation was more close to LDV experimental data. Large Eddy Simulation was a relatively appropriate method for simulation of flow field within a hydrocyclone.

scholarly journals Enhancement of Gas Holdup and Oxygen Transfer in Three-Phase Circulating Fluidized-Bed Bioreactors with Swirling Flow

2009 ◽  
Vol 42 (Supplement.) ◽  
pp. s142-s148 ◽  
Author(s):  
Sung Mo Son ◽  
Uk Yeong Kim ◽  
Ik Sang Shin ◽  
Yong Kang ◽  
Sang Done Kim ◽  
...  
Keyword(s):  
Fluidized Bed ◽  
Oxygen Transfer ◽  
Circulating Fluidized Bed ◽  
Swirling Flow ◽  
Gas Holdup ◽  
Three Phase

Simulation on the Flow Field of Mini-Hydrocyclones for Different Inlet Sizes

2013 ◽  
Vol 864-867 ◽  
pp. 1183-1191 ◽  
Author(s):  
Chao Yan ◽  
Qiang Yang ◽  
Hua Lin Wang
Keyword(s):  
Aspect Ratio ◽  
Flow Field ◽  
Solid Particles ◽  
Design And Optimization ◽  
Fluent Software ◽  
Simulation Results ◽  
Shape And Size

This paper aims to improve the separation of fine solid particles in mini-hydrocyclones by changing the shape and size of the mini-hydrocyclone inlet. This study also examines the best mini-hydrocyclone inlet shape and size. Fluent software is used to simulate the flow field of the continuous and dispersion phases in different mini-hydrocyclone. The simulation results can guide the design and optimization of mini-hydrocyclones and determine the optimum inlet aspect ratio.

scholarly journals Analysis of Separated Flows Inside an Annular Compressor Cascade Using a Low-Re-Number k-ϵ and an Algebraic Reynolds-Stress-Model

1997 ◽  
Author(s):  
Jürgen R. Lücke ◽  
Heinz E. Gallus
Keyword(s):  
Flow Field ◽  
Reynolds Stress ◽  
Three Dimensional ◽  
Separated Flow ◽  
Reynolds Stress Model ◽  
Stress Model ◽  
Mean Flow ◽  
Compressor Cascade ◽  
Production Term ◽  
Algebraic Reynolds Stress Model

The flow field inside an annular compressor cascade is numerically investigated. The mean flow features are complex three-dimensional zones of turbulent separation at hub and shroud at high inflow angles. The flow field is investigated with an implicit three-dimensional Navier-Stokes code. To predict turbulent effects the flow solver includes two different variants of a Low-Re-number k-ϵ-model and an algebraic Reynolds-stress-model. Using the Low-Re-number model the structure of the regions of separated flow are fairly well predicted. However, intensity and size of these zones are too small compared with the experimental data. Better results are produced using the anisotropic algebraic Reynolds-stress-model combined with a stagnation point modification of the turbulent production term. Stucture and intensity of the vortex systems are simulated in more detail. Static pressure distributions and loss contours are in a very good agreement with the experiments.

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