scholarly journals Analysis of Different Mould Section Sizes to Optimize the Submerged Entry Nozzle to Measure the Meniscus Fluctuation in a Continuous Casting Mould

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 564
Author(s):  
Manish Kumar ◽  
Praveen Mishra ◽  
Apurba Kumar Roy
Keyword(s):  
Flow Pattern ◽  
Wave Amplitude ◽  
Water Flow Rate ◽  
Submerged Entry Nozzle ◽  
Background Information ◽  
Operating Parameters ◽  
Flow Rates ◽  
Scale Models ◽  
Scale Down ◽  
Continuous Casting Mould

An experimental investigation has been carried out to analyse different mould section sizes to measure the meniscus fluctuation by varying different liquid flow rates and different submerged entry nozzle port angles, i.e., 0° port angles, 15° downward and 15° upward port angles. The terms of maximum surface wave fluctuation and standard deviation have been analysed for the above mentioned parameters. It was observed that a submerged entry nozzle with 0° port was found to be superior when it was compared with a 15° downward and 15° upward port nozzle. By conducting an experiment, it was observed that as the water flow rate increased, the maximum wave amplitude was found to be increasing, which results in more turbulence. Different mould section sizes were analysed to provide background information to the steelmaker to analyse the behaviour of fluid flow pattern. The operating parameters of the result obtained from the present setup were compared with the published literature, and a scale down of slab moulds can be justifiedregarding the rough flow pattern in the mould but can lack accuracy. The reason behind this statement is that the integral length scales of the turbulent flow between scaled down and full scale models can be different. Therefore, details of the flow pattern can become great differences between both types of models.

scholarly journals Influence of Submerged Entry Nozzle Port Blockage on the Meniscus Fluctuation Considering Various Operational Parameters

Metals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 269 ◽  
Author(s):  
Manish Kumar ◽  
Praveen Mishra ◽  
Apurba Kumar Roy
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Wave Amplitude ◽  
Water Flow Rate ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Water Model ◽  
Maximum Height ◽  
Operational Parameters ◽  
The Right

The continuous casting process (CCP) is the most vital part of steelmaking. The flow pattern near the submerged entry nozzle (SEN) and mould greatly influence the quality of the slab produced. The present investigation was carried out to gain knowledge regarding the meniscus fluctuation under different nozzle port blockage conditions by water model experiments. The experiments were carried out to study the effect of no blockage, 25% blockage, 50% blockage, and 75% blockage of the nozzle port on mould-level fluctuations. The result shows that when the liquid flow rate increases, the wave amplitude increases. In these experiments, the average and maximum meniscus fluctuations were measured while changing different variables such as the water flow rate, gas flow rate, and one-side percentage blockage of the SEN port while the other side was fully open. The observation shows that when the port size decreases, the fluid steel mixed from the obstructing side to the open side results in asymmetry. The average and maximum wave amplitude increases with decreasing submergence depth. It was observed that the maximum height of the standing waves in the mould continued rising on the non-blocked side of the SEN. Blockage increases from 25% to 75%, and with 75% blockage of the right side of the SEN port, the mould-level fluctuation at the left side of the mould was extreme, while that of the right side was relatively quiet.

Bubble dynamics and oxygen transfer in a hypolimnetic aerator

1998 ◽  
Vol 37 (2) ◽  
pp. 293-300 ◽  
Author(s):  
Vickie L. Burris ◽  
John C. Little
Keyword(s):  
Gas Phase ◽  
Bubble Size ◽  
Oxygen Transfer ◽  
Bubble Dynamics ◽  
Water Flow Rate ◽  
Flow Rates ◽  
Wide Range ◽  
The City ◽  
Close Fit ◽  
Water Supply Reservoirs

A hypolimnetic aerator operating in one of the City of Norfolk's water supply reservoirs was tested. Dissolved oxygen (DO) profiles, water flow rate, and gas-phase holdup were measured over a wide range of applied air flow rates. A model that was developed to predict oxygen transfer in a Speece Cone was modified to conform to the conditions of the hypolimnetic aerator. By varying a single parameter (the initial bubble size) the model was found to provide a close fit to the experimental DO profiles as well as the observed gas-phase holdup. The model was used to show that a doubling in oxygen transfer may be achieved if initial bubble size is reduced from 5 mm to 2.5 mm. Knowing the initial bubble size, it should be possible to predict water velocity by incorporating the effect of momentum. Further work is now underway to test this approach and to examine the possibility of extending this generalized model to cover the range of hypolimnetic aeration and oxygenation devices.

Synchronous Concentrating and Purifying Dilute Nickel Wastewater by Electrodeionization Technology

2011 ◽  
Vol 233-235 ◽  
pp. 351-354 ◽  
Author(s):  
Hui Xia Lu ◽  
Jian You Wang ◽  
Shao Feng Bu
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Applied Voltage ◽  
Stream Flow ◽  
Heavy Metal Ions ◽  
Pure Water ◽  
Operating Parameters ◽  
Feed Water ◽  
Water Production ◽  
Flow Rates

Applicable configuration alteration of the electrodeionization （EDI）process commonly for pure water production was carried out to treat dilute nickel wastewater in this paper. The effects of major operating parameters such as applied voltage, dilute and concentrate stream flow rates on the performance of EDI process were investigated systematically. The results showed that, with the feed water containing 50mg·L-1 Ni2+ and pH of 5.7, the dilute resistivity of the EDI could reach higher than 1.0MΩ·cm which gave a Ni2+ rejection more than 99.8% while the Ni2+ was concentrated as high as 1564mg·L-1 in the concentrate stream by optimizing the operating parameters. It was indicated that pure water production and concentrating of heavy metal ions could be simultaneously accomplished via EDI technology just in one process, valuable heavy metal and water resource could be recovered as well.

Identification of Wake Convection and Flow Outline in the Interface Region of Blade Rows With Axial Gap in a Counter Rotating Turbine

2019 ◽  
Author(s):  
Rayapati Subbarao ◽  
M. Govardhan
Keyword(s):  
Flow Pattern ◽  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Three Dimensional ◽  
Interface Region ◽  
Turbine Stage ◽  
Deviation Angle ◽  
Flow Rates ◽  
Improved Performance

Abstract In a Counter Rotating Turbine (CRT), the stationary nozzle is trailed by two rotors that rotate in the opposite direction to each other. Flow in a CRT stage is multifaceted and more three dimensional, especially, in the gap between nozzle and rotor 1 as well as rotor 1 and rotor 2. By varying this gap between the blade rows, the flow and wake pattern can be changed favorably and may lead to improved performance. Present work analyzes the aspect of change in flow field through the interface, especially the wake pattern and deviation in flow with change in spacing. The components of turbine stage are modeled for different gaps between the components using ANSYS® ICEM CFD 14.0. Normalized flow rates ranging from 0.091 to 0.137 are used. The 15, 30, 50 and 70% of the average axial chords are taken as axial gaps in the present analysis. CFX 14.0 is used for simulation. At nozzle inlet, stagnation pressure boundary condition is used. At the turbine stage or rotor 2 outlet, mass flow rate is specified. Pressure distribution contours at the outlets of the blade rows describe the flow pattern clearly in the interface region. Wake strength at nozzle outlet is more for the lowest gap. At rotor 1 outlet, it is less for x/a = 0.3 and increases with gap. Incidence angles at the inlets of rotors are less for the smaller gaps. Deviation angle at the outlet of rotor 1 is also considered, as rotor 1-rotor 2 interaction is more significant in CRT. Deviation angle at rotor 1 outlet is minimum for this gap. Also, for the intermediate mass flow rate of 0.108, x/a = 0.3 is giving more stage performance. This suggests that at certain axial gap, there is better wake convection and flow outline, when compared to other gap cases. Further, it is identified that for the axial gap of x/a = 0.3 and the mean mass flow rate of 0.108, the performance of CRT is maximum. It is clear that the flow pattern at the interface is changing the incidence and deviation with change in axial gap and flow rate. This study is useful for the gas turbine community to identify the flow rates and gaps at which any CRT stage would perform better.

scholarly journals Numerical Modelling of Metal/Flux Interface in a Continuous Casting Mould / Modelowanie Numeryczne Powierzchni Międzyfazowej Metal/Ciekły Żużel W Krystalizatorze Do Ciągłego Odlewania Stali

2015 ◽  
Vol 60 (4) ◽  
pp. 2905-2912 ◽  
Author(s):  
J. Jowsa ◽  
M. Bielnicki ◽  
A. Cwudziński
Keyword(s):  
Liquid Steel ◽  
Steel Casting ◽  
Liquid Slag ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Continuous Steel Casting ◽  
Research Areas ◽  
Slab Casting ◽  
Metal Flux ◽  
Continuous Casting Mould

The behaviour of liquid slag in the mould is one of the key research areas of the continuous steel casting process. Numerical simulations of steel casting in the mould equipped with submerged entry nozzle, intended for slab casting, have been carried out within the study. For modelling the behaviour of the interfaces of the liquid steel - liquid slag - air system, the VOF method was employed. In the conducted simulations, seven different procedures for the discretization of the interface of individual phases were tested. The computation results have revealed that the “entrapment” of fine slag portions into liquid steel occurs in the system under investigation; the cause of this phenomenon is explicated by the Kelvin-Helmholtz theory.

Effects of Water Flow Rate on Fatigue Life of Carbon Steel in Simulated LWR Environment Under Low Strain Rate Conditions

2003 ◽  
Vol 125 (1) ◽  
pp. 52-58 ◽  
Author(s):  
Akihiko Hirano ◽  
Michiyoshi Yamamoto ◽  
Katsumi Sakaguchi ◽  
Tetsuo Shoji ◽  
Kunihiro Iida
Keyword(s):  
Fatigue Life ◽  
Carbon Steel ◽  
Strain Rate ◽  
Water Flow ◽  
Flow Rate ◽  
Water Flow Rate ◽  
Flow Rates ◽  
Life Evaluation ◽  
Significant Difference ◽  
Fatigue Life Evaluation

The flow rate of water flowing on a steel surface is considered to be one of the important factors strongly influencing the fatigue life of the steel, because the water flow produces difference in the local environmental conditions. The effect of the water flow rate on the fatigue life of a carbon steel was thus investigated experimentally. Fatigue testing of the carbon steel was performed at 289°C for various dissolved oxygen contents (DO) of less than 0.01 and 0.05, 0.2, and 1 ppm, and at various water flow rates. Three different strain rates of 0.4, 0.01, and 0.001 %/s were used in the fatigue tests. At the strain rate of 0.4 %/s, no significant difference in fatigue life was observed under the various flow rate conditions. On the other hand, at 0.01 %/s, the fatigue life increased with increasing water flow rate under all DO conditions, such that the fatigue life at a 7 m/s flow rate was about three times longer than that at a 0.3 m/s flow rate. This increase in fatigue life is attributed to increases in the crack initiation life and small-crack propagation life. The major mechanism producing these increases is considered to be the flushing effect on locally corrosive environments at the surface of the metal and in the cracks. At the strain rate of 0.001 %/s, the environmental effect seems to be diminished at flow rates higher than 0.1 m/s. This behavior does not seem to be explained by the flushing effect alone. Based on this experimental evidence, it was concluded that the existing fatigue data obtained for carbon steel under stagnant or relatively low flow rate conditions may provide a conservative basis for fatigue life evaluation. This approach seems useful for characterizing fatigue life evaluation by expressing increasing fatigue life in terms of increasing water flow rate.

Effect of Bottom Structure of Submerged Entry Nozzle on Flow Field in Ultra-Thick Slab Continuous Casting Mold

2010 ◽  
Vol 154-155 ◽  
pp. 840-845 ◽  
Author(s):  
Xin Xie ◽  
Deng Fu Chen ◽  
Qiang Liu ◽  
Jia Long Shen ◽  
Zheng Peng ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Flow Pattern ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Surface Flow ◽  
Water Model ◽  
Continuous Casting Mold ◽  
Flat Bottom ◽  
Thick Slab ◽  
Flow Intensity

Submerged entry nozzle (SEN) bottom structure plays an important role in determining the flow pattern in continuous casting process. This work applies a water model to evaluate the pointed-bottom, flat-bottom and recessed-bottom nozzle performance in ultra-thick slab mold. The jet properties and surface flow are compared for the three kinds of nozzles quantitatively. The results show that flat-bottom and recessed-bottom nozzles are similar in flow pattern, but the pointed-bottom nozzle has smaller jet angle, thinner flow pattern, larger surface asymmetry rate, and higher surface flow intensity.

Experimental Studies of Rotation Efficiency of Packing on Characteristics of Counter Flow Wet Cooling Tower

2014 ◽  
Author(s):  
Khashayar Teimoori ◽  
Ali M. Sadegh
Keyword(s):  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Water Mass ◽  
Water Flow Rate ◽  
Experimental Studies ◽  
Counter Flow ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Water Mass Flow Rate

Packing in cooling towers is commonly used in nuclear power plants and air conditioning systems. However their efficiency with respect to the inlet air flow rate and the temperature of the water has not been fully investigated. In this research, the efficiency of packing rotational speed with respect to the wet counter flow of a cooling tower is experimentally investigated. In our experimental studies, six elliptical wooden plates that are equally spaced are used as a packing tower. The packing area of 0.85 m2 is considered with the following rotor speed ranges: 0.5, 3.5, 10, 15 and 17 rpm. It is assumed that the water mass flow rate is proportional to the inlet air to the tower. Six mass flow rates starting from 0.2 to 2.8 kg/h and the inlet air and water temperatures of 27°C and 45°C, respectively, are considered. The results illustrate that for the range of 0 to 5 rpm of the packing rotational speed the cooling rate of water is increased 3% for the water flow rate of 2.8 kg/h, and 24% for the water flow rate of 0.4 kg/h. Additionally, as a result of the increased rotational speed from 5 to over 17 rpm the cooling rate at both maximum and minimum water mass flow rates are increased from 13.9 to 34.4 percent, respectively. Furthermore, the water outlet temperature is reduced from 8.6°C to 3.3°C in the least and the most mass flow rates leading to the increased speed from 5 to 17 rpm, respectively. The experimental relationship between the inlet air temperature and the rotational speed of the packing has been determined. Also, the inlet water temperature at the maximum flow rate has been decreased to 3.4 and at the least water mass flow rate it has been decreased to 29 percent for the range of rotational speed from 5 to over 17 rpm of the packing rotation. All the results are depicted in several curves to show the actual variations of the variables.

scholarly journals Performance of a Cooling Tower with the Use of a New Kind of High-density Polyethylene (HDPE) Packing

2021 ◽  
Author(s):  
Nagam Obaid Kariem ◽  
◽  
Mohammed A. Rasheed ◽  
Zainab T. Al-Sharify ◽  
◽  
...  
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Water Flow ◽  
High Density Polyethylene ◽  
Cooling Tower ◽  
Water Flow Rate ◽  
Research Work ◽  
High Density ◽  
Airflow Rate ◽  
Flow Rates

This research work deals with the performance of high-density polyethylene sheets arranged in splash used as a fill for a cooling tower. “A forced-draught counter flow cooling tower” of 400 mm × 400 mm cross-sectional area and 1.7m in height was built. The fill has been studied theoretically and experimentally. Air rates of 0.6, 1.2, and 1.8 kg/s.m2 were utilized with water flow rates within the range of 1 to 1.6 kg/s.m2. The overall volumetric heat transfer coefficient, volumetric mass transfer coefficient (Mt), and the tower characteristics (Mt/L) are shown to be functions of the air and water flow rates concurrently. Four available input parameters were inlet water temperature, airflow rate, water flow rate, and full height. A computer program was prepared to perform numerical analysis for reducing data sets obtained from the plant. In addition, analysis was carried out for evaluating the volumetric heat and mass transfer coefficients along with the performance coefficient.

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