Rotary Kilns

Rotary Kilns—rotating industrial drying ovens—are used for a wide variety of applications including processing raw minerals and feedstocks as well as heat-treating hazardous wastes. They are particularly critical in the manufacture of Portland cement. Their design and operation is critical to their efficient usage, which if done incorrectly can result in improperly treated materials and excessive, high fuel costs. This professional reference book will be the first comprehensive book in many years that treats all engineering aspects of rotary kilns, including a thorough grounding in the thermal and fluid principles involved in their operation, as well as how to properly design an engineering process that uses rotary kilns. This new edition contains an updated CFD section with inclusion of recent case studies and in line with recent developments covers pyrolysis processes, torrefaction of biomass, application of rotary kilns in C02 capture and information on using rotary kilns as incinerators for hydrocarbons. Provides essential information on fluid flow, granular flow, mixing and segregation, and aerodynamics during turbulent mixing and recirculation Gives guidance on which fuels to choose, including options such as natural gas versus coal-fired rotary kilns Covers principles of combustion and flame control, heat transfer and heating and material balances New edition contains information on pyrolysis processes with low temperatures and torrefaction of biomass. It also covers calcination of petcoke, how rotary kilns are used as incinerators for chlorinated hydrocarbons. Includes updated material on CFD simulation of kiln gas and solids flow with a selection of recent case studies.

This unique book presents an in-depth analysis of all the emerging ironmaking processes, supplementing the conventional blast furnace method. Various processes for producing solid and liquid iron are discussed, including important features such as process outline, techno-economics, and process fundamentals. The present global status of each process is examined, projections for the future are made, and processes are compared. Beyond the Blast Furnace is valuable reading for process developers, because it gives them a complete picture of various process options. Conventional iron- and steelmakers as well as researchers and practitioners working in the area of alternative processes of ironmaking will also benefit from this ready reference. The book is an ideal text for undergraduate and postgraduate students in metallurgy.

The organizers of this Fifth Symposium maintained their initial objectives, namely to gather experts from both industries and universities to discuss the scientific problems involved in the preparation of heterogeneous catalysts, and to encourage as much as possible the presentation of research work on catalysts of real industrial significance. Another highlight of these symposia was to reserve a substantial part of the program to new developments in catalyst preparation, new preparation methods and new catalytic systems. The fact that chemical reactions which were hardly conceivable some years ago have become possible today through the development of appropriate catalytic systems proves that catalysis is in constant progress. The papers in this volume deal with studies of unit operations in catalyst preparation, catalyst preparation via the sol-gel route, preparation of catalysts from layered structures and pillaring of clays, preparation and modification of zeolite-based catalysts, carbon supported catalysts, preparation of oxidation catalysts and novel and unusual preparation methods.

This is an indispensable reference source and training tool not only for kiln operators, but for supervisors and management staff as well. Extensive discussions on pre-heater and pre-calciner operations are included. The appendix includes a section with conversion tables, definitions of common terms relating to rotary kilns, and a suggested outline for a training program for new operators. CONTENTS: History; Types of Rotary Kilns; Refractories; Fuels; Combustion; The Flame; Heat Transfer; Heat Balances; The Chemistry of Kiln Feed and Clinker, Reaction Zones in the Rotary Kiln; Coating and Ring Formation in a Rotary Kiln; The Air Circuit in a Rotary Kiln: Movement of the Material Through The Kiln; Kiln Operating and Control Methods; Instrumentation; Burning Zone Control; Fuel Systems; Clinker cooler Control; Kiln Exit-Gas Temperature Control; Feed-Rate Control; Kiln Starts and Shutdowns; The 27 Basic Kiln Conditions; Kiln Emergency Conditions; Safety and Accident Prevention; Appendix: A KILN OPERATOR'S QUIZ; Glossary; Conversion Tables; Index. See also: F.M. LEA's, THE CHEMISTRY OF CEMENT AND CONCRETE, Third Edition: ISBN 978-0-8206-0212-7; Kurt Peray, The Cement Manufacturer's Handbook: ISBN 0820603686. Visit us at www.chemical-publishing.com

Rotary Kilns—rotating industrial drying ovens—are used for a wide variety of applications including processing raw minerals and feedstocks as well as heat-treating hazardous wastes. They are particularly critical in the manufacture of Portland cement. Their design and operation is critical to their efficient usage, which if done incorrectly can result in improperly treated materials and excessive, high fuel costs. This professional reference book will be the first comprehensive book in many years that treats all engineering aspects of rotary kilns, including a thorough grounding in the thermal and fluid principles involved in their operation, as well as how to properly design an engineering process that uses rotary kilns. Chapter 1: The Rotary Kiln Evolution & Phenomenon Chapter 2: Basic Description of Rotary Kiln Operation Chapter 3: Freeboard Aerodynamic Phenomena Chapter 4: Granular Flows in Rotary Kilns Chapter 5: Mixing & Segregation Chapter 6: Combustion and Flame Chapter 7: Freeboard Heat Transfer Chapter 8: Heat Transfer Processes in the Rotary Kiln Bed Chapter 9: Mass & Energy Balance Chapter 10: Rotary Kiln Minerals Process Applications ·Covers fluid flow, granular flow, mixing and segregation, and aerodynamics during turbulent mixing and recirculation ·Offers hard-to-find guidance on fuels used for rotary kilns, including fuel options such as natural gas versus coal-fired rotary kilns ·Explains principles of combustion and flame control, heat transfer and heating and material balances

This book provides a fascinating study of the very important emerging field of direct reduction in which iron ore is ‘directly reduced’ in the solid-state, using either natural gas or non-coking coal, to produce a highly metallised material, referred to as sponge iron (or direct reduced iron). This intermediate product is subsequently melted in electric arc furnaces or induction furnaces (sometimes even in basic oxygen furnaces) to produce liquid steel. Such a process combination enables steel to be produced without using coking coal, which is an expensive input in the normal blast furnace—basic oxygen furnace route of steelmaking adopted in integrated steel plants. The book offers comprehensive coverage and critical assessment of various coal-based and gas-based direct reduction processes. Besides dealing with the application of the theoretical principles involved in the thermodynamics and kinetics of direct reduction, the book also contains some worked-out examples on sponge iron production. The concluding part of this seminal book summarises the present and future scenario of direct reduction, including the use of gas generated from coal in direct reduction processes. The book is primarily intended for the undergraduate and postgraduate students of metallurgical engineering. It is also a must-read for researchers, technologists and process metallurgists engaged in the rapidly developing field of direct reduction of iron oxides, which is of critical importance for India and other developing nations that are beginning to play a major role in global steelmaking.