scholarly journals Effect of Mold Width on the Flow Field in a Slab Continuous-Casting Mold with High-Temperature Velocity Measurement and Numerical Simulation

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1943
Author(s):  
Jian-Qiu Liu ◽  
Jian Yang ◽  
Chao Ma ◽  
Yi Guo ◽  
Wen-Yuan He ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Flow Field ◽  
Flow Velocity ◽  
Turbulent Kinetic Energy ◽  
Flow Rate ◽  
Gas Flow ◽  
Immersion Depth ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
Slag Entrainment

In this paper, the effects of the width of the mold on the surface velocity, flow field pattern, turbulent kinetic energy distribution, and surface-level fluctuation in the mold were studied with measurement of the flow velocity near the surface of the mold at high temperature with the rod deflection method and numerical calculation with the standard k-ε model coupled with the discrete-phase model (DPM) model for automobile exposed panel production. Under the conditions of low fixed steel throughput of 2.2 ton/min, a nozzle immersion depth of 140 mm, and an argon gas flow rate of 4 L/min, as the width of the mold increases from 880 mm to 1050 mm and 1300 mm, the flow velocity near the surface of the mold decreases. The flow direction changes from the positive velocity with the mold widths of 880 mm and 1050 mm to the unstable velocity with the mold width of 1300 mm. The calculated results are in good agreement with the measured results. The turbulent kinetic energy near the submerged entry nozzle (SEN) gradually increases, and the risk of slag entrainment increases. Under the conditions of high fixed steel throughput of 3.5 ton/min, the SEN immersion depth of 160 mm, and the argon gas flow rate of 10 L/min, as the width of the mold increases from 1600 mm to 1800 mm and 2000 mm, the velocity near the mold surface decreases. The flow velocity at 1/4 of the surface of the mold is positive with the mold width of 1600 mm, while the velocities are negative with the widths of 1800 mm and 2000 mm. The calculated results are basically consistent with the measured results. The high turbulent kinetic energy area near the nozzle expands to a narrow wall, and the risk of slag entrainment is significantly increased. In both cases of low and high fixed steel throughput, the change rules of the flow field in the mold with the width are basically the same. The argon gas flow rate and the immersion depth of SEN should be adjusted reasonably to optimize the flow field in the mold with different widths under the same fixed steel throughput in the practical production.

scholarly journals Flow Field in Slab Continuous Casting Mold with Large Width Optimized with High Temperature Quantitative Measurement and Numerical Calculation

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 261
Author(s):  
Chao Ma ◽  
Wen-yuan He ◽  
Huan-shan Qiao ◽  
Chang-liang Zhao ◽  
Yi-bo Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Pattern ◽  
Flow Rate ◽  
Casting Speed ◽  
Gas Flow ◽  
Immersion Depth ◽  
Mold Surface ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
Slag Entrainment

In this paper, the rod deflection method was applied to quantitatively measure velocity near the mold surface at high temperatures and the k-ε model coupled with a discrete phase model (DPM) was adopted to simulate the flow field in the mold. The calculated results match very well with the measured results under all the present conditions. Under the conditions of the large mold width of 1800 mm, 1.1 m/min casting speed and 140 mm submerged entry nozzle (SEN) immersion depth, the velocity near the mold surface decreases with increasing the argon gas flow rate. When the argon gas flow rate is 6 L/min, the flow pattern is the double roll flow (DRF). When the argon gas flow rate is increased to 10 L/min and 14 L/min, the flow pattern is the single roll flow (SRF), and the risk of slag entrainment increases. With an argon gas flow rate of 10 L/min, and an immersion depth of 160 mm, the velocity near the mold surface sensitively increases with increasing the casting speed. When the casting speed is 1.1 m/min, an intermediate flow (IF) is formed with the intensified mold surface fluctuation, which can easily result in slag entrainment defects. When the casting speed is only increased to 1.2 m/min, the velocity near the mold surface changes drastically and is close to the upper limit velocity of 0.4 m/s. When the casting speed is 1.1 m/min, and the argon gas flow rate is 10 L/min, the velocity near the mold surface is obviously increased with increasing the immersion depth. When the immersion depth of the nozzle increases from 140 mm and 160 mm to 180 mm, the flow pattern changes from SRF or IF to DRF. When the bottom shape of the SEN changes from mountain to well, the velocity near the mold surface decreases. We suggest adopting the well-bottom nozzle to reduce the risk of slag entrainment.

PIV Study of Flow in an Aerated Tank with a Hollow Blade Turbine

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Xuan Geng ◽  
Zhengming Gao ◽  
Yuyun Bao
Keyword(s):  
Liquid Phase ◽  
Energy Dissipation ◽  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Flow Rate ◽  
Liquid Flow ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
Mean Velocity ◽  
Image Velocimetry

Liquid phase hydrodynamics in an aerated tank (ID = 0.19 m) stirred by a half elliptical blade disk turbine (HEDT) have been investigated using particle image velocimetry (PIV) under both aerated and unaerated conditions. The effect of the gas flow rate on the aerated mean velocity of the liquid phase, turbulent kinetic energy and turbulent kinetic energy dissipation are discussed, and their comparisons with those under unaerated conditions are also carried out. Under aerated conditions, the presence of gas does not remarkably change the velocity pattern of the liquid phase. When the direction of the liquid flow is the same as the buoyancy, the liquid is accelerated up to 10.4% by bubbles at position of z/T=0.8 and r/T=0.45; while the liquid flow reversely, the liquid is decelerated about 37.5% under the gas flow rate of 0.2 vvm at the position of z/T=0.25 and r/T=0.45. The turbulent kinetic energy in the bulk flow increases after introducing gas phase, and the average turbulent kinetic energy of the upper, middle and lower regions at 0.2 vvm are increased by 37.3%, 37.8% and 142.7%, respectively. Large-eddy PIV approach is carried out to estimate the distribution of the turbulence kinetic energy dissipation. The result shows that the distribution of the turbulent kinetic energy dissipation is similar as those of turbulent kinetic energy.

scholarly journals Optimization of Flow Field in Slab Continuous Casting Mold with Medium Width Using High Temperature Measurement and Numerical Simulation for Automobile Exposed Panel Production

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 9
Author(s):  
Peng Jiang ◽  
Jian Yang ◽  
Tao Zhang ◽  
Gangjun Xu ◽  
Hongjun Liu ◽  
...  
Keyword(s):  
Flow Field ◽  
Flow Pattern ◽  
Gas Flow ◽  
Mold Surface ◽  
Level Fluctuation ◽  
Gas Flow Rate ◽  
Continuous Casting Mold ◽  
Argon Gas ◽  
Surface Level ◽  
Slab Continuous Casting

In the present work, mathematical modeling combined with measurement of the velocities near mold surface with rod deflecting method at the high temperature was carried out to optimize the flow field of slab continuous casting mold with medium width of 1230 mm for the production of an automobile exposed panel. The results show that the measured results of the velocities near the mold surface are in good agreement with the calculated results. The velocities near the mold surface increase with increasing the casting speed and decreasing the argon gas flow rate. When the casting speed is increased from 1.0, to 1.3, 1.5, and 2.0 m/min, the flow pattern in the mold is changed from single-roll flow (SRF), to unstable flow (UF), and then to double-roll flow (DRF), the top surface level fluctuations has the smallest value at 1.5 m/min. When the argon gas flow rate is 1 and 4 L/min, the velocity near the mold surface has a moderate value, and the flow pattern in the mold is DRF and the top surface level fluctuation is small and symmetrical. When the submerged entry nozzle (SEN) submergence depth is increased to 200 mm, the velocities near the mold surface decrease, and the top surface level fluctuation becomes small. The optimized flow field in the mold can be judged to be favorable to the surface quality of the automobile exposed panel; if the velocities near the mold surface are relatively small, the flow pattern in the mold is DRF and the top surface level fluctuation is small and symmetrical.

scholarly journals Effects of argon gas flow rate on laser-welding

2012 ◽  
Vol 31 (2) ◽  
pp. 316-326 ◽  
Author(s):  
Yasuko TAKAYAMA ◽  
Rie NOMOTO ◽  
Hiroyuki NAKAJIMA ◽  
Chikahiro OHKUBO
Keyword(s):  
Laser Welding ◽  
Flow Rate ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
Argon Gas

scholarly journals Effects of Gas Flow on Spectral Properties of Plasma Jet Induced by Microwave

2018 ◽  
Vol 15 (1) ◽  
pp. 81-86 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
Flow Rate ◽  
Applied Voltage ◽  
Gas Flow ◽  
Microwave Plasma ◽  
Plasma Jet ◽  
Gas Temperature ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
Jet Length ◽  
Maximum Value

In this paper, a construction microwave induced plasma jet(MIPJ) system was used to produce a non-thermal plasma jet at atmospheric pressure, at standard frequency of 2.45 GHz and microwave power of 800 W. The working gas Argon (Ar) was supplied to flow through the torch with adjustable flow rate using flow meter regulator. The influence of the MIPJ parameters such as applied voltage and argon gas flow rate on macroscopic microwave plasma parameters were studied. The macroscopic parameters results show increasing of microwave plasma jet length with increasing of applied voltage, argon gas flow rate where the plasma jet length exceed 12 cm as maximum value. While the increasing of argon gas flow rate will cause increasing into the argon gas temperature, where argon gas temperature the exceed 350 ? as maximum value and study the effect of gas flow rate on the optical properties

Morphological and optical properties of graphene film synthesized from waste of industrial cooking oil, AYAMAS using DTCVD method

2020 ◽  
Vol 14 (2) ◽  
pp. 24
Author(s):  
Nurfazianawatie Mohd Zin
Keyword(s):  
Optical Properties ◽  
Flow Rate ◽  
Gas Flow ◽  
Graphene Film ◽  
Nickel Surface ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
X Ray ◽  
Cooking Oil ◽  
Vis Spectroscopy

The synthesis of graphene by double thermal chemical vapor deposition (DTCVD) using waste of industrial cooking oil (WICO) as a natural carbon source was investigated. The synthesis parameter (Argon gas flow rate) was varied between 50sccm to 300sccm by 50sccm increments. The function of Argon gas is to provide ambient condition, remove the atmospheric air from the tube and could improve the crystallinity of graphene during synthesis. WICO (from AYAMAS food processing) was placed in the first furnace (precursor furnace) and nickel was placed in the second furnace (deposition furnace). During the synthesis, elevated quantities of carbon from the source material are separated and precipitated on the Nickel surface. The sample were characterized by using Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Energy Dispersive X-ray (EDX), and Ultraviolet Visible (UV-Vis) spectroscopy. Based on FESEM images, at 250sccm, hexagonal graphene formation was observed. Besides, optical properties can be seen by UV-Vis and as the results show that 250sccm is the highest reflectivity value. Consequently, graphene synthesis from WICO using various Argon gas flow rate as precursor is successfully demonstrated.

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