scholarly journals Optimal Design of the Submerged Entry Nozzle for Thin Slab Continuous Casting Molds

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1223
Author(s):  
Mingtao Xuan ◽  
Min Chen
Keyword(s):  
Temperature Distribution ◽  
Wave Height ◽  
Casting Speed ◽  
Continuous Caster ◽  
Submerged Entry Nozzle ◽  
Thin Slab ◽  
Recirculation Flow ◽  
Defect Rate ◽  
Port Area ◽  
The Mean

For the purpose of increasing the capacity of an Angang Strip Production (ASP) continuous caster and the surface quality of a medium-thin slab with mold sections of 150 × (1020–1540) mm2, the present work investigated the influences of the submerged entry nozzle (SEN) structure and main operating parameters on the flow characteristic and temperature distribution in the mold by physical and numerical simulations. The results showed that the typical “double-roll” flow and a central jet were formed through the three-port SEN. With the original SEN, the mean wave height exceeded the critical value of 5.0 mm after the casting speed was increased due to the strong upper recirculation flow. By the slight increment of the bottom port area and the side port angle of SEN, the mean wave height was obviously decreased below 4.4 mm due to the depressing of the upper recirculation flow after the casting speed increased. Meanwhile, the temperature distribution was slightly changed by using the optimized SEN. The practical application showed that the breakout rate decreased from 0.349% to 0.107% and the surface defect rate decreased from 0.54% to 0.19% by using the optimized SEN, while throughput reached the new level of 3.96 t/min.

Mathematical Modeling of Transport Processes in Funnel Shaped Mold of Steel Thin Slab Continuous Caster

2011 ◽  
Vol 133 (6) ◽  
Author(s):  
A. Hajari ◽  
S. H. Seyedein ◽  
M. R. Aboutalebi
Keyword(s):  
Flow Pattern ◽  
Casting Speed ◽  
Continuous Caster ◽  
Transport Processes ◽  
Inlet Temperature ◽  
High Heat Flux ◽  
Thin Slab ◽  
Surface Turbulence ◽  
Submergence Depth ◽  
Slab Continuous Caster

In this work a three-dimensional fluid flow and heat transfer model was developed to predict the flow pattern and superheat dissipation in funnel shaped mold of a thin slab continuous caster with a novel tetrafurcated design for the submerged entry nozzle. Low Reynolds k−ε turbulent model was adopted to account for the turbulent effect. The transport equations were solved numerically using finite volume method. The results were compared with a full scale water model of the caster. Good agreement between mathematical and physical models was obtained. Parametric studies were carried out to evaluate the effect of casting speed, nozzle submergence depth, and inlet temperature on the superheat dissipation, flow pattern, and surface turbulence in the mold region. The results indicate a special flow pattern and heat distribution in the caster while using a tetrafurcated nozzle. Aiming to achieve more product capacity, in the case of casting with lower superheat temperature, a higher casting speed, together with higher submergence depth, is recommended in order to avoid surface turbulence and high heat flux across the narrow face.

Numerical analysis of local heat flux and thin-slab solidification in a CSP funnel-type mold with electromagnetic braking

2020 ◽  
Vol 117 (6) ◽  
pp. 602
Author(s):  
Heping Liu ◽  
Jianjun Zhang ◽  
Hongbiao Tao ◽  
Hui Zhang
Keyword(s):  
Heat Flux ◽  
Casting Speed ◽  
Shell Growth ◽  
Local Heat ◽  
Operating Conditions ◽  
Thin Slab ◽  
Wide Face ◽  
Slab Width ◽  
Steel Grades ◽  
Local Heat Flux

In this article, based on the actual monitored temperature data from mold copper plate with a dense thermocouple layout and the measured magnetic flux density values in a CSP thin-slab mold, the local heat flux and thin-slab solidification features in the funnel-type mold with electromagnetic braking are analyzed. The differences of local heat flux, fluid flow and solidified shell growth features between two steel grades of Q235B with carbon content of 0.19%C and DC01 of 0.03%C under varying operation conditions are discussed. The results show the maximum transverse local heat flux is near the meniscus region of over 0.3 m away from the center of the wide face, which corresponds to the upper flow circulation and the large turbulent kinetic energy in a CSP funnel-type mold. The increased slab width and low casting speed can reduce the fluctuation of the transverse local heat flux near the meniscus. There is a decreased transverse local heat flux in the center of the wide face after the solidified shell is pulled through the transition zone from the funnel-curve to the parallel-cure zone. In order to achieve similar metallurgical effects, the braking strength should increase with the increase of casting speed and slab width. Using the strong EMBr field in a lower casting speed might reverse the desired effects. There exist some differences of solidified shell thinning features for different steel grades in the range of the funnel opening region under the measured operating conditions, which may affect the optimization of the casting process in a CSP caster.

scholarly journals Generation of Reverse Meniscus Flow by Applying An Electromagnetic Brake

2021 ◽  
Author(s):  
Alexander Vakhrushev ◽  
Abdellah Kharicha ◽  
Ebrahim Karimi-Sibaki ◽  
Menghuai Wu ◽  
Andreas Ludwig ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Lorentz Force ◽  
Applied Magnetic Field ◽  
Numerical Study ◽  
Flow Direction ◽  
Experimental Studies ◽  
Submerged Entry Nozzle ◽  
Mean Flow ◽  
Slab Caster ◽  
The Mean

AbstractA numerical study is presented that deals with the flow in the mold of a continuous slab caster under the influence of a DC magnetic field (electromagnetic brakes (EMBrs)). The arrangement and geometry investigated here is based on a series of previous experimental studies carried out at the mini-LIMMCAST facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR). The magnetic field models a ruler-type EMBr and is installed in the region of the ports of the submerged entry nozzle (SEN). The current article considers magnet field strengths up to 441 mT, corresponding to a Hartmann number of about 600, and takes the electrical conductivity of the solidified shell into account. The numerical model of the turbulent flow under the applied magnetic field is implemented using the open-source CFD package OpenFOAM®. Our numerical results reveal that a growing magnitude of the applied magnetic field may cause a reversal of the flow direction at the meniscus surface, which is related the formation of a “multiroll” flow pattern in the mold. This phenomenon can be explained as a classical magnetohydrodynamics (MHD) effect: (1) the closure of the induced electric current results not primarily in a braking Lorentz force inside the jet but in an acceleration in regions of previously weak velocities, which initiates the formation of an opposite vortex (OV) close to the mean jet; (2) this vortex develops in size at the expense of the main vortex until it reaches the meniscus surface, where it becomes clearly visible. We also show that an acceleration of the meniscus flow must be expected when the applied magnetic field is smaller than a critical value. This acceleration is due to the transfer of kinetic energy from smaller turbulent structures into the mean flow. A further increase in the EMBr intensity leads to the expected damping of the mean flow and, consequently, to a reduction in the size of the upper roll. These investigations show that the Lorentz force cannot be reduced to a simple damping effect; depending on the field strength, its action is found to be topologically complex.

Stochastic Analysis of Temperature Distribution in a Solid With Random Heat Conductivity

1988 ◽  
Vol 110 (1) ◽  
pp. 23-29 ◽  
Author(s):  
Da Yu Tzou
Keyword(s):  
Thermal Conductivity ◽  
Temperature Distribution ◽  
Heat Conductivity ◽  
Stochastic Analysis ◽  
Solid Medium ◽  
Mean Value ◽  
Random Response ◽  
Thermal Failure ◽  
Numerical Examples ◽  
The Mean

Stochastic temperature distribution in a solid medium with random heat conductivity is investigated by the method of perturbation. The intrinsic randomness of the thermal conductivity k(x) is considered to be a distribution function with random amplitude in the solid, and several typical stochastic processes are considered in the numerical examples. The formulation used in the present analysis describes a situation that the statistical orders of the random response of the system are the same as those of the intrinsic random excitations, which is characteristic for the problem with extrinsic randomness. The maximum standard deviation of the temperature distribution from the mean value in the solid medium reveals the amount of unexpected energy experienced by the solid continuum, which should be carefully inspected in the thermal-failure design of structures with intrinsic randomness.

Measurements of the Initial Ground Temperature in GSHP System

2014 ◽  
Vol 919-921 ◽  
pp. 1707-1715
Author(s):  
Ya Su Zhou ◽  
Wan Lan Ju ◽  
Zheng Liu
Keyword(s):  
Temperature Distribution ◽  
Small Difference ◽  
Engineering Application ◽  
Ground Temperature ◽  
Engineering Applications ◽  
Average Water Temperature ◽  
Arithmetic Average ◽  
Testing Method ◽  
Shallow Zone ◽  
The Mean

The initial ground temperature (IGT) is one of the most important parameters in designing a ground source heat pump (GSHP) system and evaluating its performance. In this paper, three initial ground temperature test methods are introduced. Except the shallow zone, the ground temperature distribution measured from direct and indirect testing method has very small difference. In direct test, the temperature sensor must be embedded when burying the tube in the borehole which is hard to operate in engineering applications. Thus the direct testing method is suggested to be applied in the scientific research. The indirect testing method could be used in engineering applications. The mean ground temperature could be calculated from temperature distribution except the shallow zone temperature. The results from three calculating methods have a quite small difference. Therefore, the arithmetic average method is suggested for scientific and engineering application to calculate the mean ground temperature. The mean ground temperature is also gotten in TRT conveniently. In the condition of velocity 0.7m/s, water was circulated in the tube system with no heat source for 30 minutes. The average water temperature could be regard as the mean ground temperature with sufficient accuracy.

scholarly journals Combined Effects of EMBr and SEMS on Melt Flow and Solidification in a Thin Slab Continuous Caster

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 948
Author(s):  
Changjun Wang ◽  
Zhongqiu Liu ◽  
Baokuan Li
Keyword(s):  
Continuous Caster ◽  
Solidification Rate ◽  
Potential Method ◽  
Suppressive Effect ◽  
Thin Slab ◽  
Dispersion Effect ◽  
Melt Flow ◽  
Simultaneous Application ◽  
Iron And Steel ◽  
Slab Continuous Caster

Electromagnetic fields have emerged as powerful tools for addressing current problems in thin slab continuous casting processes in the iron and steel industry. Substantial studies have been undertaken on the fundamental effects of electromagnetic brakes (EMBr) and strand electromagnetic stirring (SEMS). However, little attention has been focused on melt flow and solidification in a thin slab continuous caster with the simultaneous application of an EMBr and SEMS. The present study aimed to predict transient fields in the caster using a large eddy simulation and an enthalpy-porosity method. The electric potential method was applied in the braking process, and the conductivity change with solidification was considered. The suppressive effect on the intensity of the nozzle jet, the balance effect on the mold flow, and a dispersion effect could be observed. The dispersion effect was a novel finding and was beneficial to a flatter nozzle jet. In contrast, SEMS caused a highly turbulent flow in the strand. A large vortex could be observed in the casting direction. The solidified shell became more uniform, and the solidification rate became obviously slower. These findings supported the view that a high-quality thin slab can be produced by the application of an EMBr and SEMS.

scholarly journals The Characteristics of West Season Wind and Wave as well as Their Impacts on Ferry Cruise in The Kalianget-Kangean Cruise Route, Madura, Indonesia

2021 ◽  
Vol 29 (3) ◽  
Author(s):  
Viv Djanat Prasita ◽  
Lukman Aulia Zati ◽  
Supriyatno Widagdo
Keyword(s):  
Wind Speed ◽  
Wave Height ◽  
The West ◽  
Wind Speeds ◽  
Wave Patterns ◽  
Time Stamps ◽  
The Mean ◽  
Two Peaks ◽  
The Impact ◽  
Descriptive Statistical Analysis

The wind and wave conditions in the waters of the Kalianget-Kangean cruise route in the west season are relatively high so that these winds and waves can have a dangerous impact on that cruise route. The aim of this research was to analyze the characteristics of wind speed and wave height over a 10 year period (2008-2017), as well as to evaluate the weekly patterns for three months (December 2017-February 2018). These time stamps represent the west season in waters at Kalianget-Kangean route, and to identify the impact of winds and wave on this path. The method used in this research is descriptive statistical analysis to obtain the mean and maximum values ​​of wind speed and wave height. Wind and wave patterns were analyzed by WRPlot and continued with mapping of wind and wave patterns in the waters of Kalianget-Kangean and its surroundings. The data used was obtained from the Meteorology, Climatology and Geophysics Agency. The results show wind and wave characteristics with two peaks formed regularly between 2008-2017, marking the west and east monsoons. In addition, the wind speed and wave height were generally below the danger threshold, ie <10 knots and <2 m, respectively. However, there are exceptions in the west season, especially at the peak in January, where the forces are strengthened with a steady blowing direction. The maximum wind speed reaches and wave height reaches 29 knots and 6.7 m, respectively. The weekly conditions for both parameters from December 2017 to February 2018 were relatively safe, for sailing. Moreover, January 23-29, 2018 featured extreme conditions estimated as dangerous for cruise due to the respective maximum values of 25 knots and 3.8 m recorded. The channel is comparably safe, except during the western season time in December, January, February, characterized by wind speeds and wave height exceeding 21 knots and 2.5 m, correspondingly.

scholarly journals FUTURE CHANGES IN SPECTRAL WAVE CLIMATE AROUND JAPAN UNDER GLOBAL WARMING

2020 ◽  
pp. 10
Author(s):  
Tomoya Shimura ◽  
Nobuhito Mori
Keyword(s):  
Global Warming ◽  
Wave Height ◽  
Climate Change Impacts ◽  
Wave Climate ◽  
Structure Design ◽  
Future Projections ◽  
Wave Statistics ◽  
The Mean ◽  
Ocean Wave Climate ◽  
East Asia Region

Future projections of ocean wave climate related with global warming has been conducted for the assessment of climate change impacts on coastal disaster, beach morphology, and coastal structure design. In this study, we conduct the high-resolution future wave climate projection in the East Asia region and detail analysis on wave climate based on two-dimensional wave spectra in addition to conventional wave statistics (significant wave height). Future changes in wave height, period and direction can be discussed consistently owing to analysis on the mean wave spectra.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/FEYPZFRr5SQ

scholarly journals Impact of addition of ca on clogging of SEN and magnetic properties of non-oriented silicon steel

2019 ◽  
Vol 55 (1) ◽  
pp. 39-46
Author(s):  
W. Kong ◽  
D.G. Cang
Keyword(s):  
Magnetic Properties ◽  
Continuous Casting ◽  
Casting Speed ◽  
Magnetic Induction ◽  
Core Loss ◽  
Submerged Entry Nozzle ◽  
Silicon Steel ◽  
The Core ◽  
Dissolved Aluminum ◽  
The Impact

The submerged entry nozzle (SEN) clogging has been happening during continuous casting (or CC for short) for nonoriented silicon steel. To solve the problem, the paper studied a flow rate through SEN, a node attached to one of them, and the impact on the clogging. The results showed that when SEN is clogged seriously, the casting speed has to decrease below the target casting speed and that SEN clogging can be predicted by comparing the actual value and the theoretical one of a casting speed. Al2O3 and its composite inclusions caused the SEN clogging and the addition of Ca can solve SEN clogging during CC of the silicon steel both theoretically and practically. Furthermore, the impact of the addition of Ca on the magnetic properties of the steel were analyzed. The results showed that the core loss and the magnetic induction of the silicon steel decreased by using the addition of Ca, which generated more dissolved Aluminum, and the addition of Ca generated more harmful textures, which reduced the magnetic induction.

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