Interaction of Injector Design, Bubble Size, Flow Structure, and Turbulence in Ladle Metallurgy

2018 ◽  
Vol 90 (2) ◽  
pp. 1800346 ◽  
Author(s):  
Kwaku B. Owusu ◽  
Tim Haas ◽  
Prince Gajjar ◽  
Moritz Eickhoff ◽  
Pruet Kowitwarangkul ◽  
...  
Keyword(s):  
Flow Structure ◽  
Bubble Size ◽  
Ladle Metallurgy ◽  
Injector Design

scholarly journals Physical study of the impact of injector design on mixing, convection and turbulence in ladle metallurgy

2019 ◽  
Vol 22 (2) ◽  
pp. 538-547
Author(s):  
Prince Gajjar ◽  
Tim Haas ◽  
Kwaku Boateng Owusu ◽  
Moritz Eickhoff ◽  
Pruet Kowitwarangkul ◽  
...  
Keyword(s):  
Ladle Metallurgy ◽  
Physical Study ◽  
The Impact ◽  
Injector Design

scholarly journals Improving the Performance of Surface Flow Generated by Bubble Plumes

Fluids ◽  
2021 ◽  
Vol 6 (8) ◽  
pp. 262
Author(s):  
Hassan Abdulmouti
Keyword(s):  
Free Surface ◽  
Flow Structure ◽  
Flow Rate ◽  
Bubble Size ◽  
Gas Flow ◽  
Surface Flow ◽  
Bubble Motion ◽  
Gas Flow Rate ◽  
Two Phase ◽  
Bubble Plumes

Gas–liquid two-phase flow is widely used in many engineering fields, and bubble dynamics is of vital importance in optimizing the engineering design and operating parameters of various adsorptive bubble systems. The characteristics of gas–liquid two-phase (e.g., bubble size, shape, velocity, and trajectory) remain of interest because they give insight into the dynamics of the system. Bubble plumes are a transport phenomenon caused by the buoyancy of bubbles and are capable of generating large-scale convection. The surface flow generated by bubble plumes has been proposed to collect surface-floating substances (in particular, oil layers formed during large oil spills) to protect marine systems, rivers, and lakes. Furthermore, the surface flows generated by bubble plumes are important in various types of reactors, engineering processes, and industrial processes involving a free surface. The bubble parameters play an important role in generating the surface flow and eventually improving the flow performance. This paper studies the effects of temperature on bubble parameters and bubble motion to better understand the relationship between the various bubble parameters that control bubble motion and how they impact the formation of surface flow, with the ultimate goal of improving the efficiency of the generation of surface flow (i.e., rapidly generate a strong, high, and wide surface flow over the bubble-generation system), and to control the parameters of the surface flow, such as thickness, width, and velocity. Such flow depends on the gas flow rate, bubble size (mean bubble diameter), void fraction, bubble velocity, the distance between bubble generator and free surface (i.e., water height), and water temperature. The experiments were carried out to measure bubble parameters in a water column using the image visualization technique to determine their inter-relationships and improve the characteristics of surface flow. The data were obtained by processing visualized images of bubble flow structure for the different sections of the bubble regions, and the results confirm that temperature, bubble size, and gas flow rate significantly affect the flow structure and bubble parameters.

Measurement of Bubbly Flow in a Vertical Pipe Using Ultrasonic Doppler Method

2003 ◽  
Author(s):  
Hideki Murakawa ◽  
Hiroshige Kikura ◽  
Masanori Aritomi ◽  
Michitsugu Mori
Keyword(s):  
Flow Structure ◽  
Void Fraction ◽  
Flow Rate ◽  
Liquid Flow ◽  
Bubble Size ◽  
Bubbly Flow ◽  
Velocity Profiles ◽  
Circular Pipe ◽  
Vertical Pipe ◽  
Doppler Method

In order to clarify the microscopic flow structure, the ultrasonic Doppler method was applied to the measurement of two-phase bubbly flow in vertical pipe (i.d.50mm). Liquid flow structure might strongly be influenced by the characteristic of the injected bubbles, i.e. bubbles’ size and void fraction. In this study, a bubble generator was newly designed with the purpose to control the bubble size and void fraction, independent of liquid main-flow rate. The experiment was performed at z/d = 66 from the bubble generator. Liquid flow rates were of the Reynolds numbers ranging from Rem = 3700 to 6200. The gas flow rate was constant at JG = 0.00348(m/s) at the measurement position. By analyzing the bubbles’ picture, it was confirmed that bubble size distribution and average bubble size were almost constant if the liquid flow rate were changed. The ultrasonic Doppler method has the capability of measuring the instantaneous velocity profiles of both phases at the same time. By processing the data based on pattern recognition, the recorded data can be classified to several groups. Using this method, the authors have tried to measure the bubbly flow in rectangular channel. In the present study, the application of this method to bubbly flow in circular pipe was satisfactory to obtain the liquid velocity distribution in bubbly flow and surrounding bubbles. From these results, it was clarified that velocity profile in bubbly flow in circular pipe has a maximum value near the pipe wall. Furthermore, velocity profiles around the bubble are influenced by leading bubbles.

Mixing Characteristics of an Axial-Flow Rotor: Experimental and Numerical Study

2005 ◽  
Vol 3 (1) ◽  
Author(s):  
Fouzi Kerdouss ◽  
Laszlo Kiss ◽  
Pierre Proulx ◽  
Jean-Francois Bilodeau ◽  
Claude Dupuis
Keyword(s):  
Flow Structure ◽  
Bubble Size ◽  
High Speed ◽  
Numerical Study ◽  
Axial Flow ◽  
Three Dimensions ◽  
Water Model ◽  
Two Phase ◽  
Gas Dispersion ◽  
Break Up

In the metallurgical industry, various types of rotors are used for the injection and distribution of gas and for homogenizing molten metal. In the present work, the liquid-gas two-phase flow around an axial type impeller is studied in a water model, in order to analyze the bubble break-up and coalescence and metal mixing. Details like primary and secondary vortex structure, gas flooding between the blades and gas dispersion are recorded by using high speed photography.A mathematical model that takes into account the combined effect of bubble break-up and coalescence is implemented in the commercial computational fluid dynamics (CFD) software FLUENT. In the proposed work, the impeller is explicitly described in three dimensions using Multiple Reference Frame Model. Dispersed gas and bubbles dynamics in the turbulent water are modeled using an Eulerian-Eulerian approach with dispersed k-epsilon turbulent model. The model predicts spatial distribution of gas hold-up, average bubble size and flow structure. Good qualitative agreement between physical model and simulation is achieved when comparing the bubble size distribution, flow structure and mixing.

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