Research on Optimization of Flow Field in 60t Tow-Strand Tundish by Hydraulic Model

2012 ◽  
Vol 605-607 ◽  
pp. 1311-1316
Author(s):  
Jian Jun Zhang ◽  
Wen Fang Gao ◽  
Zhu Gang Peng
Keyword(s):  
Flow Field ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Behavior ◽  
Hydraulic Model ◽  
Dead Volume ◽  
Average Residence Time ◽  
Original Scheme ◽  
The Dead

The original scheme flow behavior of WISCO 60t two-strand tundish was investigated by means of hydraulic model. Optimized scheme was selected by flow field Character analyzing and residence time distribution (RTD) curves analyzing of each scheme. The results show that the dead volume Vd of optimized scheme decreases to 5.33%, reduced by 77.4% compared with the original scheme. The average residence time Ta of optimized scheme increases to 364.5s, increased by 70.5s compared with the original scheme. The optimized scheme favors more reasonable flow field and inclusions removing in the tundish. It is more adaptive than the original scheme for the tow-strand tundish.

scholarly journals Modelling of Fluid Flow and Residence Time Distribution in a Five-strand Tundish

2020 ◽  
Author(s):  
Dong-Yuan Sheng ◽  
Qiang Yue
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Volume Fraction ◽  
Fluid Dynamic ◽  
Flow Characteristics ◽  
Passive Scalar ◽  
Control Device ◽  
Dead Volume ◽  
Cfd Modelling

The quantified residence time distribution (RTD) provides a numerical characterization of mixing in the continue casting tundish, thus allowing the engineer to better understand the metallurgical performance of the reactor. This paper describes a computational fluid dynamic (CFD) modelling study for analyzing the flow pattern and the residence time distribution in a five-strand tundish. Two passive scalar transport equations are applied to separately calculate the E-curve and F-curve in the tundish. The numerical modelling results are compared to the water modelling results for the validation of the mathematical model. The volume fraction of different flow regions (plug, mixed and dead) and the intermixing time during the ladle changeover are calculated to study the effects of the flow control device (FCD) on the tundish performance. The result shows that a combination of the U-baffle with deflector holes and the turbulence inhibitor has three major effects on the flow characteristics in the tundish: i) reduce the extent of the dead volume; ii) evenly distribute the liquid streams to each strand and iii) shorten the intermixing time during the ladle changeover operation.

scholarly journals Hydraulic Characteristics, Residence Time Distribution, and Flow Field of Electrochemical Descaling Reactor Using CFD

Processes ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1896
Author(s):  
Bolin Hu ◽  
Xiaoqiang Zhang ◽  
Zhaofeng Wang ◽  
Zixian Wang ◽  
Yuanfan Ji
Keyword(s):  
Steady State ◽  
Energy Consumption ◽  
Flow Field ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Short Circuit ◽  
Hydraulic Characteristics ◽  
Plate Height ◽  
Plate Spacing

This paper uses computational fluid dynamics (CFD) to simulate flow field distribution inside an electrochemical descaling reactor in three dimensions. First, the reactor flow field was obtained by steady-state simulation, and the grid independence was verified. Then, the steady state of the flow field was judged to ensure the accuracy of the simulation results. Transient simulations were performed on the basis of steady-state simulations, and residence time distribution (RTD) curves were obtained by a pulse-tracing method. The effects of plate height and plate spacing on reactor hydraulic characteristics (flow state and backmixing) were investigated using RTD curves, and the results showed that increasing the plate height and decreasing the plate spacing could make the flow more similar to the plug flow and reduce the degree of backmixing in the reactor. The flow field details provided by CFD were used to analyze the reactor flow field and were further verified to obtain the distribution patterns of dead and short circuit zones. Meanwhile, information regarding pressure drops was extracted for different working conditions (490, 560, and 630 mm for pole plate height and 172.6, 129.45, and 103.56 mm for pole plate spacing), and the results showed that increasing the pole plate height and decreasing the pole plate spacing led to an increased drop in pressure. In this case, a larger pressure drop means higher energy consumption. However, increasing the pole plate height had a smaller effect on energy consumption than decreasing the pole plate spacing.

Suspension flow behavior and particle residence time distribution in helical tube devices

2019 ◽  
Vol 360 ◽  
pp. 1371-1389 ◽  
Author(s):  
Lukas Hohmann ◽  
Mira Schmalenberg ◽  
Mathusah Prasanna ◽  
Martin Matuschek ◽  
Norbert Kockmann
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Flow Behavior ◽  
Suspension Flow ◽  
Particle Residence Time ◽  
Helical Tube

scholarly journals Modeling of Fluid Flow and Residence-Time Distribution in a Five-Strand Tundish

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1084 ◽  
Author(s):  
Dong-Yuan Sheng ◽  
Qiang Yue
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Volume Fraction ◽  
Fluid Dynamic ◽  
Flow Characteristics ◽  
Passive Scalar ◽  
Control Device ◽  
Dead Volume ◽  
Cfd Modeling

Quantified residence-time distribution (RTD) provides a numerical characterization of mixing in the continuous casting tundish-thus allowing the engineer to better understand the metallurgical performance of the reactor. This study describes a computational fluid dynamic (CFD) modeling study for analyzing the flow pattern and the residence-time distribution in a five-strand tundish. Two passive scalar-transport equations were applied to separately calculate the E-curve and F-curve in the tundish. The numeric modeling result were compared to water-modeling results to validate the mathematical model. The volume fraction of different flow regions (plug, mixed and dead) and the intermixing time during the ladle changeover were calculated to study the effects of the flow control device (FCD) on the tundish performance. From the results of CFD calculations, it can be stated that a combination of the U-baffle with deflector holes and the turbulence inhibitor had three major effects on the flow characteristics in the tundish: (i) to reduce the extent of the dead volume; (ii) to evenly distribute the liquid streams to each strand and (iii) to shorten the intermixing time during the ladle changeover operation.

Dispersion Number Studies in ChemicalMechanical Planarization

2003 ◽  
Vol 767 ◽  
Author(s):  
Ara Philipossian ◽  
Erin Mitchell
Keyword(s):  
Fluid Dynamics ◽  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Dispersion Model ◽  
Flow Behavior ◽  
Plug Flow ◽  
Operating Conditions ◽  
The Coefficient Of Friction ◽  
Dispersion Number

AbstractThis study explores aspects of the fluid dynamics of CMP processes. The residence time distribution of slurry under the wafer is experimentally determined and used to calculate the Dispersion Number (Δ) of the fluid in the wafer-pad region based on a dispersion model for non-ideal reactors. Furthermore, lubrication theory is used to explain flow behaviors at various operating conditions. Results indicate that at low wafer pressure and high relative pad-wafer velocity, the slurry exhibits nearly ideal plug flow behavior. As pressure increases and velocity decreases, flow begins to deviate from ideality and the slurry becomes increasingly more mixed beneath the wafer. These phenomena are confirmed to be the result of variable slurry film thicknesses between the pad and the wafer, as measured by changes in the coefficient of friction (COF) in the pad-wafer interface.

scholarly journals Spatial Variation of Longitudinal Dispersion in LECA-Based Vegetated Beds

2012 ◽  
Vol 326-328 ◽  
pp. 279-284
Author(s):  
António Albuquerque
Keyword(s):  
Residence Time ◽  
Time Distribution ◽  
Residence Time Distribution ◽  
Loading Rate ◽  
Solid Material ◽  
Dead Volume ◽  
Nitrogen Compounds ◽  
In Series ◽  
Reactive Tracer ◽  
Tracer Experiments

The evaluation of the dispersion in vegetated beds may allow indentifying mechanisms that affect the transport and reaction of solutes, namely organic and nitrogen compounds. A set of non-reactive tracer experiments (slag injection) was performed in a vegetated bed (a mesocosm with a LECA-based substratum and colonized withPhragmites australis) used for the removal of organic and nitrogen pollutant loads. Loads of approximately 300 mg COD/L and 30 mg NH4-N/L and a hydraulic loading rate of 3.5 cm/d were used. The results showed a delay in all the residence time distribution (RTD) curves and a variation in the dimensionless residence time (μ(m,θ)) of the E(θ) curves, which means that the mass centre of the impulse was late relatively to the expected one. A strong dispersion and tracer retention (due to the presence of stagnated areas and internal recirculation) was observed, especially in the first 33 cm of the bed, which seems to have been related to the presence of complex clusters of roots, solid material, biofilm and LECA particles. An analytical solution of the Multiple-Tanks-in-Series (MTS) model well represents the RTD curves obtained in the tracer experiments. The detected dispersion and dead volume ratios (7% to 12%) did not affect the performance of the bed, which presented mean removal efficiencies of 85% and 60.4% for COD and NH4-N, respectively.

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