Table Of Content

FUELS, FURNACES AND REFRACTORIES R.C. GUPTA Former Professor and Head Department of Metallurgical Engineering Indian Institute of Technology–BHU Varanasi Delhi-110092 2016 FUELS, FURNACES AND REFRACTORIES R.C. Gupta © 2016 by PHI Learning Private Limited, Delhi. All rights reserved. No part of this book may be reproduced in any form, by mimeograph or any other means, without pe r mission in writing from the publisher. ISBN-978-81-203-5157-8 The export rights of this book are vested solely with the publisher. Published by Asoke K. Ghosh, PHI Learning Private Limited, Rimjhim House, 111, Patparganj Industrial Estate, Delhi-110092 and Printed by Mohan Makhijani at Rekha Printers Private Limited, New Delhi-110020. To Bharat Ratna Awardee Pandit Mahamana Madan Mohan Malaviyaji The Freedom Fighter, Great National Leader, Visionary, Founder of Banaras Hindu University having first Mining and Metallurgical Engineering Department in India and Mentor and Patron of my Father Table of Contents Table of Contents Preface Acknowledgements 1. Fuels, Furnaces and Refractories Need and Their Significance 1.1 Fuels 1.1.1 Definition 1.1.2 Classification of Fuels 1.1.3 Use of Fuels by Metallurgical Industries 1.1.4 Merits and Limitations of Fuels 1.1.5 Fuel Requirements by Some Major Metallurgical Units 1.2 Furnaces: Need and Type 1.2.1 Definition 1.2.2 Basic Features 1.2.3 Methods of Furnace Classification 1.2.4 Basic Components of Furnace 1.2.5 Factors Responsible for Selection of Furnace 1.3 Refractories 1.3.1 Definition and Function of Refractory 1.3.2 Classification of Refractory based on Chemical Nature 1.3.3 Classification of Refractory based on Other Considerations 1.3.4 Forms of Refractories: Shaped and Monolithic 1.3.5 Applications 1.3.6 Performance of Refractory 2. Solid FuelsCoal and Coke 2.1 Origin of Coal 2.1.1 Peat Formation (Biochemical Period) 2.1.2 Conversion of Peat into Coal (Dynamochemical Period) 2.2 Type, Rank, Class and Grade of Coal 2.3 Coal Constituents 2.3.1 Petrological Constituents in Coal 2.3.2 Elemental Constituents in Coal 2.3.3 Constituents Important for Coal Use 2.4 Coal Classification 2.5 Properties of Coal and its Testing 2.5.1 Ultimate Analysis of Coal 2.5.2 Proximate Analysis of Coal 2.5.3 Caking Property of Coal and Test Methods 2.5.4 Fusion Behaviour of Coal (Coal Rheology or Plasticity) 2.5.5 Coal Ash Fusion Behaviour 2.5.6 Coal Calorific Value 2.5.7 Coal Grindability Test (HGI) 2.6 Coal Preparation and Cleaning 2.6.1 Impurities in Coal 2.6.2 Liberation of Impurities 2.6.3 Principles for Separation of Coal from Impurities 2.6.4 Coal Breaking Equipment 2.6.5 Coal Sizing Equipment 2.6.6 Coal Cleaning Methods 2.6.7 Hand Picking of Coal Impurities 2.6.8 Wet Gravity Separation 2.6.9 Dry Gravity Separation 2.6.10 Float and Sink Method 2.6.11 Froth Floatation Method 2.7 Coal Storage 2.7.1 Aim of Coal Storage 2.7.2 Problems with Coal Storage 2.7.3 Factors Promoting Natural Oxidation of Coal 2.7.4 Precautions Required during Storage 2.8 Coke Making 2.8.1 Coke Making Methods 2.8.2 Beehive Coke Making Method 2.8.3 Non-recovery Coke Oven Method 2.8.4 By-product Coke Oven Method 2.9 Coke Properties and Testing 2.9.1 Coke Appearance 2.9.2 Cell Size 2.9.3 Coke Size 2.9.4 Coke Porosity 2.9.5 Coke Analysis 2.9.6 Coke Strength 2.9.7 Coke Strength after Reaction (CSR) 2.9.8 Coke Reactivity 2.10 Carbon Structure and its Reactivity 2.10.1 Carbon and its Structure 2.10.2 Carbon Structure and its Gasification Rate 2.10.3 Carbon Reactivity Determination Techniques 2.11 Coke Oven Emissions 2.12 Applications of Coal in Metallurgical Plants 2.12.1 Coke Making 2.12.2 Sponge Iron Making in Rotary Kilns 2.12.3 Smelting Reduction (SR) Process (COREX) 2.13 Use of Coke for Various Applications 2.13.1 Blast Furnace 2.13.2 Cupola 2.13.3 Water Gas 2.14 Numerical Problems 2.14.1 Surface Moisture 2.14.2 Proximate Analysis 2.14.3 Coal Blending and Coke Making 2.14.4 Coke Oven Design 3. Liquid Fuels 3.1 Origin of Liquid Fuels 3.2 Sources of Liquid Fuel 3.2.1 Crude Petroleum 3.2.2 Oil Shale 3.2.3 Coal Tar Fuel (CTF) 3.2.4 Coal Liquefaction 3.3 Commonly Used Petroleum Products 3.3.1 Petrol (Gasoline) 3.3.2 White Spirit 3.3.3 Naphtha 3.3.4 Kerosene 3.3.5 Diesel 3.3.6 Furnace Oil 3.4 Properties and Testing Techniques for Liquid Fuels 3.4.1 Viscosity 3.4.2 Flash Point and Fire Point 3.4.3 Specific Gravity 3.4.4 Calorific Value 3.4.5 Sulphur in Oils 3.4.6 Carbon Residue 3.4.7 Ash Content 3.4.8 Cloud Point 3.4.9 Pour Point 3.4.10 Sludge and Sediments in Oil 3.4.11 Water in Oil 4. Gaseous Fuels 4.1 Natural Gas 4.2 Reformed Natural Gas 4.2.1 Technique Used by HyL III 4.2.2 Technique Used by MIDREX Process 4.3 LPG (Liquefied Petroleum Gas) or Bottled Gas 4.4 Blast Furnace Gas 4.5 Coke Oven Gas 4.6 LD Steel Gas 4.7 COREX Gas 4.8 Producer Gas 4.8.1 Properties of Producer Gas 4.8.2 Manufacturing Process of Producer Gas 4.8.3 Flexibility of Use of Fuel for Generating Producer Gas 4.8.4 Applications 4.9 Water Gas (or Blue Gas) 4.9.1 Water Gas Generation Unit 4.9.2 Fuel Quality for Water Gas Generation 4.9.3 Applications of Water Gas 4.10 CarburetTed Water Gas 4.11 Oil Gas 4.12 Testing of Gaseous Fuels 4.12.1 Gas Analysis Methods 4.12.2 Gas Analysis by Orsat Apparatus 4.12.3 Gas Calorimeter 4.13 Storage and Safety of Gaseous Fuels 4.13.1 Gas Holder 5. Combustion of Fuels 5.1 Definitions and Terminology 5.2 Combustion Systems 5.2.1 Combustion Process Requirements 5.2.2 Air for Combustion 5.2.3 Combustion System Design Factors 5.3 Combustion Mechanism for Solid Fuels 5.3.1 Solid Fuel Bed Combustion on Hearth or Grate 5.3.2 Pulverised Fuel Combustion through Burner 5.3.3 Solid Fuel Combustion in Fluidised Bed 5.4 Liquid Fuel Combustion and Liquid Fuel Burners 5.4.1 Methods for Atomising Liquid Fuel 5.4.2 Types of Burner 5.4.3 Oil Ignition Systems 5.4.4 Flame Detection 5.4.5 Oil Combustion Mechanism 5.4.6 Flame Properties 5.5 Gaseous Fuel Combustion 5.5.1 Flame Propagation 5.5.2 Gas Burner Types 5.6 Numerical Problems 5.6.1 Combustion of Solid Fuel 5.6.2 Gaseous Fuel Combustion 6. Furnaces and its Accessories 6.1 Commonly Used Furnaces 6.1.1 Solid Fuel based Furnaces 6.1.2 Liquid Fuel based Furnaces 6.1.3 Gaseous Fuel based Furnaces 6.1.4 Furnaces based on Electricity 6.1.5 Chemical Energy based Furnaces 6.2 Basic Principles of Furnace Design 6.2.1 Chamber Design 6.2.2 Burners 6.2.3 Fans and Blowers 6.2.4 Chimney 6.3 Furnace Instruments 6.3.1 Temperature Measuring Devices 6.3.2 Pressure Measuring Equipment 6.3.3 Flow Rate 6.4 Major Furnace Accessories 6.4.1 Waste Gas Cleaning Systems 6.4.2 Waste Gas Collecting Systems for Melting Units 6.4.3 Thermal Shields 6.4.4 Acoustic Chambers 7. Refractories 7.1 Properties of Refractory 7.1.1 High Temperature Behaviour 7.1.2 Corrosion Resistance 7.1.3 Erosion Resistance 7.1.4 Thermal Conductivity 7.1.5 Porosity