cr0264_11 - 11 Modeling of Secondary Steelmaking Processes...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
11 ©2001 CRC Press LLC Modeling of Secondary Steelmaking Processes Dipak Mazumdar, Ph.D. Department of Materials and Metallurgical Engineering Indian Institute of Technology 11.1 INTRODUCTION A comprehensive study of various hydrodynamic phenomena such as fluid flow, mixing, and mass transfer in full-scale liquid steel processing vessels poses serious experimental difficulties. High operating temperatures, opacity of liquid steel, and the relatively large size of industrial metal processing units preclude direct experimental observations. Consequently, it has been customary to study the process dynamics of steelmaking operations with the aid of physical and mathematical models. While the physical modeling of metallurgical processing operations dates back to at least the early 1960s, 1 mathematical models have come of age relatively recently (i.e., mid 1970s). 2 The progress in mathematical modeling has been largely achieved through advances in the computing power and speed of digital computers, which are now available at moderate cost. Concurrent with these advances have been the numerical algorithms and special computing procedures needed to solve transient, three-dimensional forms of the turbulent Navier–Stokes or Reynolds stress equations (Chapter 3) and their equivalent heat and mass counterparts. It is important to stress at this point that physical and mathematical modeling are not alternatives but most often must be pursued in a complementary fashion. This is illustrated in Figure 11.1 , 3 which essentially indicates that mathematical modeling, physical modeling, and actual plant-scale measurements may all be the ingredients of a successful investigation. Indeed, owing to the complexities associated with the operating conditions, several iterations may be required between mathematical modeling and physical measurements (i.e., this is normally termed model tuning ) before the desired level of understanding finally emerges. 11.2 MODELING TECHNIQUES 11.2.1 P HYSICAL M ODELING Here, the industrial vessel is known as the prototype, and its laboratory-scale counterpart is known as the model . Laboratory-scale modeling of various secondary steelmaking operations has most frequently used water as the modeling medium to represent molten steel. The most important single property in this context, apart from its ubiquity, is that its kinematic viscosity (that is, molecular
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
©2001 CRC Press LLC viscosity/density) is essentially equivalent to that of molten steel at 1600°C (i.e., within 10%). Flow visualization experiments in aqueous systems using dyes or other tracers have therefore proved to be very helpful in developing a qualitative understanding of various flows. Similarly, more detailed information on flow characteristics has also been possible by measuring velocity fields by tracking the motion of neutrally buoyant particles, hot wire or hot film anemometry, by laser Doppler anemometry, and, lately, by PIV (particle image velocimetry). In addition, measurements of resi- dence time distribution
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/08/2009 for the course CME MAT E 112 taught by Professor Dr.atoo during the Fall '09 term at University of Alberta.

Page1 / 19

cr0264_11 - 11 Modeling of Secondary Steelmaking Processes...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online