Transport Phenomena in Metallurgical

Processes (MMC 401)

Dr. Manas Kumar Mondal

Associate Professor,
Department of Metallurgical and Materials Engineering
National Institute of Technology, Durgapur
 Disclaimer
The study materials/presentations are solely meant for academic purposes and they can
be reused, reproduced, modified, and distributed by others for academic purposes only
with proper acknowledgements.

Lecture 1
Topics to be covered
Introduction, Conservation, fluid statics

Fluid flow: Newton's law of viscosity, Non-newtonian fluids

Continuity equation, Navier-Stokes equations, Laminar flow

Turbulence and experimental correlations, concept of friction factor

Flow through porous media, fluidized bed, Ergun equation. EX: centrifugal casting, bottom gating sytstem

Modes of heat transfer, Industrial examples , Fundamental law and Subsidiary law

Concept of thermal resistance and overall heat transfer coefficient, Differential equation of heat conduction

Conduction-convection system, Moving fins, Application in estimating heat losses from furnaces, Two dimensional steady state heat
conduction
Lumped heat capacity analysis, Time constant and response time of temperature measuring instruments, Heisler's charts, application in heat
treatment and solidification.

Concept of boundary layer, correlation for external flow and internal flow, continuous casting cooling system, ,heat losses from hot surfaces

View factor between surfaces, radiation heat transfer in furnace enclosures, reactors in used in materials processing, radiation shields Case
studies involving multimode heat transfer in materials processing.

Fick's Laws of diffusion, advection due to diffusion, case of evaporation of liquid through a column, Analogy between mass and heat
transfer, mass transfer coefficient, application in gas-solid reactions such as oxidation, reduction etc.
References:
 D.R. Poirier and G.H. Geiger, “Transport Phenomena in Materials Processing”, (Springer International Publishers.
Switzerland,2016 ).
 Julian Szekely and N.J. Thermelis, “Rate Phenomena in Process Metallurgy” ,(John Wiley & Sons Inc (1 November
1971)).
 R. Byron Bird, Warren E. Stewart, and Edwin N. Lightfoot, “TRANSPORT PHEOMENA”, (OHN WILEY & SONS,
Inc.
 , 2002).
 D. R. Gaskell, “An Introduction to Transport Phenomena in Materials Engineering”, (MOMENTUM PRESS, LLC,
NEW JERSEY, 2013).

 S. P. Sukhatme, “A Textbook on Heat Transfer”, Fourth Edition (University Press India Ltd., 2005).

 J. P. Holman, “Heat Transfer”, (The McGraw-Hill Companies, Inc., )

 Course Outcomes

CO1: Learn fundamentals of Fluid flow, heat transfer and mass transfer

CO2: Identify nature of fluid flow and methods of heat transfer & mass transfer

CO3: Design & analyze ideal & non-ideal systems

CO4: Learn industrial applications of Fluid flow, heat transfer and mass transfer

CO5: Solve Fluid flow, heat transfer and mass transfer problems of different difficulty levels
through tutorials
Introduction
HEAT TRANSFER
Some problems of interest in heat transfer.

1. Heat loss through thermal insulation on a steam pipe.

2. Heat transfer of water flowing through a tube.
3. Heat transfer in an electric furnace.
PROBLEM 1:- Heat loss through thermal insulation on a steam pipe.

 In many industrial plants, steam is required for various process at a number of

places. The usual practice is to generate the steam at one location and to feed it
through a pipe 10 cm diameter steam used for such a purpose it shown in figure
1.
 In the situation under consideration, the super heated steam at a pressure of 5 bar
and a temperature of 170C is being generated and is flowing through the pipe.
Figure 1
 It is necessary to provide thermal insulation on the outside of pipe along the
length in under to reduce heat loss from the system to surrounding. There by the
condensation of the steam as in figure 1.

 The heat loss rate per unit length of the pipe will, in general, decrease as
thickness of insulation is increased.

The problem is to determined the thickness of insulation to be used so that heat loss
rate is reduce at some specific value.
PROBLEM 2: Heat transfer of water flowing through tube

 Cooling water of 30C enters a 2.5cm diameter, horizontal tube on the

outside surface of which low pressure steam at 50C is condensing.

 The tube is one of a bundle of tubes constituting a shell and tube

condenser in thermal power plant.

 As the water moving along the tube, it picks up heat from the
condensing steam and its temperature asymptotically approaches 50C
for an infinitely long tube.

The problem of interest is: what will be the exit temperature of the water if the tube bundle is 2 meter long?
PROBLEM 3: Heat transfer in an electric furnace.

A steel strip which to be annealed is passed continuously through a

temperature in electric furnace.

The strip enters the furnace at room temperature and its temperature is
raised as its moves along the length of furnace.

Efficient operation requires the temperature of the steel to just exceed the
critical temperature for annealing as it leaves the furnace.

The problem facing the heat transfer engineer would be: For a given furnace temperature, what should the velocity of the
strip be?
The modes of heat transfer:

 Conduction

 Convection

 Radiation
 Conduction
 Convection

The transfer of energy from one region to another due to macroscopic motion in a fluid, added on to the energy transfer by
conduction is called heat transfer by convection.

Forced convection

When fluid motion is caused by an external agency such as pump or

blower the situation is said to be one of forced convection.

Natural or free convection

When there is no such external agency and fluid motion occurs due to density variation
cased by temperature difference, the situation is said to be one of natural or free
convection.
Radiation
All the physical matter in the solid, liquid or gaseous state emits thermal
radiation in the form of electromagnetic waves because of vibrational
and rotational movement of the molecules and atoms which make up the
matter.

Characteristic of radiation
1. The radiation emitted at all temperature, the rate of emission increases with the
temperature level.

2. Unlike conduction and convection, this mode of heat transfer does not required a
material medium for energy transfer to occurs.

Medium may be solid, liquid or vacuum.