Heat and Mass Transfer

Overview

Detailed Syllabus - Lectures:
Radiative Heat Transfer (5 hours):
 Modes of Heat Transfer.
 Blackbody and real surface radiation.
 Absorptivity, reflectivity, transmissivity, irradiation and radiosity
 Radiative shape factors, radiation between surfaces with complex geometries, electrical analogies.

Forced Convection (5 hours):
 Newton's Law of cooling.
 Convective heat transfer coefficient.
 Nusselt number, Reynold number, Prandtl number
 Boundary layer theory.
 Flow over flat plates.
 Flow across cylinders.
 Flow in tubes.
 Logarithmic mean temperature difference.
 Pressure drop.

Natural Convection (3 hours):
 Physical mechanism of natural convection, volume expansion coefficient, Grashof number.
 Natural convection correlations.
 Combined natural and forced convection.

Heat Exchangers (6 hours):
 Applications and types of heat exchangers.
 Selection of heat exchangers.
 Temperature profile in heat exchangers.
 Basic equations in heat exchanger design.
 Overall heat transfer coefficient.
 Fouling factors.
 Log mean temperature difference – calculation for parallel-flow and counter-flow heat exchangers, special operating conditions for condensers, evaporators/boilers, and correction factors for multipass and cross-flow heat exchangers.
 The heat exchanger effectiveness (ε) – number of transfer units (NTU) method for heat exchanger analysis for various types of heat exchangers.
 Shell-and-tube heat exchanger design and sizing.
 Design procedure, construction details, and design considerations.
 Tube-side and shell-side heat transfer and pressure drop.
 Reboilers.
 Condensation and boiling.

Unsteady State Heat Transfer (6 hours):
 Introduction: 0D to 3D transient problems.
 Unsteady state conduction equation.
 Lumped capacitance method.
 Unsteady state heat conduction in various geometries: analytical method, semi-infinite solid, unsteady state in large flat plates.
 Charts for average temperature in plates, cylinders, and spheres with negligible resistance.

Distillation (9 hours):
 Vapour-liquid equilibria.
 Flash distillation and cascades.
 Multicomponent distillation: Rachford-Rice equations and Newton’s iterative method.
 McCabe-Thiele method:
 Live steam injection.
 Multiple feeds.
 Side streams.
 Ponchon-Savarit method for binary distillation.

Solvent Extraction (4 hours):
 Liquid-liquid extraction introduction and applications.
 Examples of ternary systems and ternary phase diagrams.
 Totally and partially immiscible systems.
 Stagewise contact: Continuous countercurrent multistage extraction and cascade efficiencies.

Interphase and General Mass Transfer (3 hours):
 General introduction to turbulent mass transfer.
 Empirical equations for mass transfer.
 Two-film theory.
 Individual and overall mass transfer coefficients.

Gas Absorption (5 hours):
 Gas-liquid equilibria.
 Counter-current flow absorption.
 Minimum liquid-gas ratio for absorbers.
 Number of plates using absorption factor.
 Absorption columns: packed column and tray tower.
 Mass transfer with continuous contact: height equivalent to a theoretical plate, the transfer unit, determination of the number of transfer units, determination of the number of transfer units, height of a transfer unit.


Detailed Syllabus –Tutorials (19 Hours):
The students are provided with tutorial and worked examples of the above lecture material. Tutorial classes are an integral element of the module.

 1.Radiative heat transfer (2 hours) – Dr E. Themistou
 2.Forced and natural convection (2 hours ) - Dr. M. Blesic
 3.Heat exchangers (3 hours) – Dr. M. Blesic
 4.Unsteady state heat transfer (2 hours ) - Dr. M. Blesic
 5.Distillation (3 hour) - Dr A. Quddusi
 6.Solvent extraction (3 hour) - Dr A. Quddusi
 7.Interface and general mass transfer (2 hour) - Dr. N. Gui.
 8.Gas absorption (2 hour) - Dr. N. Gui.

Detailed Syllabus – Labs (9 Hours):
 Students will be divided into groups. Each group will carry out experiments based on:

 1. Boiler Heat Transfer Unit (2 hours)
 2. Turbulent Flow Counter-Current Heat Exchanger (2 hours)
 3. Distillation column (2 hours)
 4. Liquid/liquid extraction (2 hours)
 5. Gas absorption column (1 hour)

 An individual pre-lab report is submitted for each experiment. There is an individual lab performance mark is given for 3 experiments while the other 2 experiments (Liquid/Liquid Extraction and Distillation Column) have a more detailed Practical Skills Assessment. There are two post-lab multiple choice quizzes (one for gas adsorption and one for boiling heat & turbulent flow combined), one poster design and one full report style post-lab.

Learning Objectives

OOn completion of this module the student should be able to:

 Explain and apply the concept of convective heat transfer (A1)
 Explain and apply the concept of radiation heat (A2)
 Understand in depth the unsteady state heat transfer (E)
 Apply the concept of the heat exchanger analysis, design and sizing (E)
 Understand in-depth advanced concepts of distillation such as multiple feeds, side streams, and live steam injection (E)
 Apply the concept of mass transfer in extraction processes and design countercurrent multistage extraction processes, solve problems on general and interphase mass transfer (A3)
 Understand the concept of gas absorption processes and design gas absorption column (E)
 Solve the distillation problem using the Ponchon-Savarit method for binary distillation (A4)

Skills

Learners are expected to demonstrate the following on completion of the module:
 Application of the concepts of heat transfer and design to heat transfer systems.
 An appreciation of the design and operation of mass transfer process.
 Improved mathematical and problem solving skills.
 An ability to use specific and general computer packages for solving chemical engineering design problems.
 Ability to utilise specific chemical engineering application software in solving chemical engineering problems, such as Matlab.

Assessment

Course Requirements:
 Lab attendance 80 %
 Post-lab assignment submission 80 %
 Examination mark veto 40% (20% from each section)
 Laboratory mark veto 40 %
 Heat transfer homework assignment average mark veto 40 %
 Mass transfer homework assignment average mark veto 40 %
 Module pass mark veto 40 %

Assessment Profile
Element type Element weight (%)
1. Examination (3hrs) 50
2. Assessment (Homework Assignments 4) 30
3. Continual Assessment Labs 20