Handbook of industrial drying third edition

The users can extrapolate the use of drying systems, by design and management, to a variety of products. As a special feature, a complete listing of books written on the subject of drying is included. The book provides excellent coverage of the cross-disciplinary nature of drying by utilizing well-known authors from many countries of the world. Mujumdar and his associates have assembled an excellent up-to-date handbook.

The common thread throughout the book is the movement of heat and moisture as well as the movement and handling of products. Also included are instrumentation, sensors, and controls that are important for quality control of products and efficiency of operation. The emphasis on the design of equipment to expedite these processes in an economical manner is appropriate and useful.

The word handbook is sometimes used disparagingly to describe a reference for quick answers to limited questions or problems. In that sense this book is more than a handbook—the knowledge base provided permits the user to build different systems for products other than those covered. Carl W. Foreword to the Second Edition The second edition of the Handbook of Industrial Drying continues the tradition of the editor and the publisher as international leaders in providing information in the field of industrial drying.

Some 50 authors from 15 countries have written 43 chapters plus 3 appendices. There are 21 new chapters, plus 2 new appendices. All chapters have been updated or revised. The mark of an outstanding handbook is that it provides current information on a subject—in this case multidisciplinary in nature—understandable to a broad audience. A balanced approach of covering principles and practices provides a sound basis for the presentations.

Students, academics, consultants, and industry people can find information to meet their needs. Researchers, designers, manufacturers, and sales people can benefit from the book as they consider elements or components related to drying as well as the system itself.

New material has been added to provide the latest information on minimizing environmental impacts, increasing energy efficiency, maintaining quality control, improving safety of operation, and improving the control of drying systems. New sections or chapters have been added to cover in detail microwave drying; infrared drying; impinging stream dryers; use of superheated steam and osmotic dehydration; and drying of biotechnological materials, tissue and towels, peat, coal, and fibrous materials.

The information in this book can be categorized as product related, equipment related, and the relationship between the two—the system of drying. For products not specifically covered, or for the design of dryers not detailed, users can select closely related applicable information to meet many needs. The user may want to pursue a subject in considerably more detail.

Pertinent references, but not voluminous overwhelming bibliographies, are included at the end of each chapter. An appendix devoted to an annotated bibliography is also included. Foreword to the Third Edition The Handbook of Industrial Drying, as a result of the great success of its first and second editions, has gained high reputation among readers interested in the process of drying.

In the last three decades we have observed a growing interest in the multidisciplinary subject of drying which had resulted in a major increase of research activity, publication of several monographs, book series, technical papers, international journals, several drying conference series in almost all continents, etc.

To keep abreast with all these scattered sources of information in a broad area like drying is extremely difficult for most readers in academia and industry alike.

So, the third edition of the Handbook, nearly a decade after the second edition, will play a very important role in providing comprehensive, updated information and a view of the current state of the art in industrial drying as a more cohesive whole. It maintains the essential interdisciplinary character addressing a broad academic and industrial readership. This book gives the possibility for selfstudy and of finding a clear overview of the fundamentals and practical information in broad aspects and problems of drying technology.

A few chapters have been deleted from the second edition due to space limitations. New sections have been added to encompass the latest data on drying of several materials foods, wood, herbal medicines, sludge, grain, nano size products, fish and seafood, etc. So practically, this edition can be treated as a truly new Handbook of Industrial Drying based on the latest achievements in the drying area.

Finally, having in mind the international character of the authors, this Handbook gives readers a chance to get acquainted in considerable detail with the literature sources published not only in English but also in other languages. Key relevant references are included at the end of each chapter. Preface to the First Edition Drying of solids is one of the oldest and most common unit operations found in diverse processes such as those used in the agricultural, ceramic, chemical, food, pharmaceutical, pulp and paper, mineral, polymer, and textile industries.

It is also one of the most complex and least understood operations because of the difficulties and deficiencies in mathematical descriptions of the phenomena of simultaneous—and often coupled and multiphase—transport of heat, mass, and momentum in solid media.

Drying is therefore an amalgam of science, technology, and art or know-how based on extensive experimental observations and operating experience and is likely to remain so, at least for the foreseeable future.

Industrial as well as academic interest in solids drying has been on the rise for over a decade, as evidenced by the continuing success of the Biennial Industrial Drying Symposia IDS series. The emergence of several book series and an international journal devoted exclusively to drying and related areas also demonstrates the growing interest in this field.

The significant growth in research and development activity in the western world related to drying and dewatering was no doubt triggered by the energy crunch of the early s, which increased the cost of drying several-fold within only a few years.

However, it is worth noting that continued efforts in this area will be driven not only by the need to conserve energy, but also by needs related to increased productivity, better product quality, quality control, new products and new processes, safer and environmentally superior operation, etc. This book is intended to serve both the practicing engineer involved in the selection or design of drying systems and the researcher as a reference work that covers the wide field of drying principles, various commonly used drying equipment, and aspects of drying in important industries.

Since industrial dryers can be finely categorized into over variants and, furthermore, since they are found in practically all major industrial sectors, it is impossible within limited space to cover all aspects of drying and dryers. We have had to make choices.

For detailed information on the fundamentals of drying, the reader is referred to various textbooks in this area.

The volume is divided into four major parts. Part I covers the basic principles, definitions, and process calculation methods in a general but concise fashion. The second part is devoted to a series of chapters that describe and discuss the more commonly used industrial dryers. Novel and less prevalent dryers have been excluded from coverage; the reader will find the necessary references in Appendix B, which lists books devoted to drying and related areas in English as well as other languages.

Part III is devoted to the discussion of current drying practices in key industrial sectors in which drying is a significant if not necessarily dominant operation. Some degree of repetition was unavoidable since various dryers are discussed under two possible categories. Most readers will, however, find such information complementary as it is derived from different sources and generally presented in different contexts.

Because of the importance of gas humidity measurement techniques, which can be used to monitor and control the convective drying operation, Part IV includes a chapter that discusses such techniques. Energy savings in drying via the application of energy recovery techniques, and process and design modifications, optimization and control, and new drying techniques and nonconventional energy sources are also covered in some depth in the final part of the book.

Finally, it is my pleasant duty to express my sincerest gratitude to the contributors from industry and academia, from various parts of the world, for their continued enthusiasm and interest in completing this major project. The comments and criticisms received from over 25 reviewers were very valuable in improving the contents within the limitations of space.

Many dryer manufacturers assisted me and the contributors directly or indirectly, by providing nonproprietary information about their equipment. My heartfelt thanks go to Chairman Mau for his kindness, continuous encouragement, and contagious enthusiasm throughout this project. Over the past four years, many of my graduate students provided me with enthusiastic assistance in connection with this project.

Without the assistance of my coauthors, it would have been impossible to achieve the degree of coverage attained in this book. I wish to record my appreciation of their efforts.

Indeed, this book is a result of the combined and sustained efforts of everyone involved. Arun S. Mujumdar Preface to the Second Edition The second edition of the Handbook of Industrial Drying is a testimonial to the success of the first edition published in Interest in the drying operation has continued to increase on a truly global scale over the past decade. For example, over papers have been presented at the biennial International Drying Symposia IDS since its inception in Drying Technology—An International Journal published some pages in seven issues in compared with just over , only a decade earlier.

A handbook is expected to provide the reader with critical information and advice on appropriate use of such information compiled in a readily accessible form.

It is intended to bring together widely scattered information and know-how in a coherent format. Since drying of solids is a multidisciplinary field—indeed, a discipline by itself—it is necessary to call on the expertise of individuals from different disciplines, different industrial sectors, and several countries. A quick perusal of the list of contributors will indicate a balanced blend of authorship from industry as well as academia.

An attempt has been made to provide the key elements of fundamentals along with details of industrial dryers and special aspects of drying in specific industries, e. The first edition contained 29 chapters and 2 appendixes; this one contains 43 chapters and 3 appendixes.

Aside from the addition of new chapters to cover topics missing from the first one, a majority of earlier chapters have been updated—some fully rewritten with new authorship. Thus, this book will be a valuable addition even to the bookshelves that already hold the first edition. For example, an extensive chapter is added in Part I on transport properties needed for dryer calculations.

Chapters on infrared drying and the novel impinging stream dryers are added to Part II. Part III contains the largest enhancement with ten new chapters while Part IV is completely new except for the chapter on humidity measurements.

A two-volume set of this magnitude must depend on the direct and indirect contributions of a large number of individuals and organizations. Clearly it is impossible to name them all. I am grateful to all the contributors for the valuable time and effort they devoted to this project.

The companies and publishers who have permitted us to reproduce some of their copyrighted artwork are acknowledged for their support. Appropriate credits are given in the text where applicable.

Exergex Corporation, Brossard, Quebec, Canada provided all the secretarial and related assistance over a three-year period. Without it this revision would have been nearly impossible. Over the past two years most of my graduate students and postdoctoral fellows of McGill University have provided me with very enthusiastic assistance in various forms in connection with this project.

In particular, I wish to express my thanks to Dr. Kudra for his continued help in various ways. Purnima, Anita, and Amit Mujumdar kindly word-processed numerous chapters and letters, and helped me keep track of the incredible paperwork involved.

The encouragement I received from Dr. Hall was singularly valuable in keeping me going on this project while handling concurrently the editorial responsibilities for Drying Technology—An International Journal and a host of other books. Finally, the staff at Marcel Dekker, Inc. Preface to the Third Edition From the success of the second edition of the Handbook of Industrial Drying the need for an updated and enhanced edition is realized at this time. Interest in industrial drying operations has been growing continuously over the last three decades and still shows no signs of abatement.

This unit operation is central to almost all industrial sectors while exposure to its fundamentals and applications is minimal in most engineering and applied science curricula around the world.

The escalating interest in drying is evidenced by the large number of international, regional, and national conferences being held regularly around the world, which are devoted exclusively to thermal and nonthermal dehydration and drying. Although deceptively simple, the processes involved are still too complex to be described confidently in mathematical terms. This means that the design and analyses of industrial dryers remain a combination of science, engineering, and art.

It is necessary to have both know-how and know-why of the processes involved to improve the design and operation of dryers. This book represents a comprehensive compendium of collected knowledge of experts from around the world. We are grateful to them for contributing to this effort. As in the earlier editions, we have a blend of academic and industry-based authors. The academics were carefully selected to ensure they also have industrial background so that readers can reliably utilize the knowledge embedded in this book.

Nevertheless, we need to include information and resources available in the public domain; despite our best intentions and high degree of selectivity, we cannot assume responsibility for validity of all the data and information given in this book. Readers must exercise due diligence before using the data in an industrial design or operation. About two thirds of this book contains new material written by new authors using recent literature.

A few topics from the second chapter are deleted. Numerous chapters are totally rewritten with new authorship. At least ten new chapters have been added to make the coverage encyclopedic.

I believe that individuals and libraries who have the second edition in their collection should keep that as an independent reference. The material in it is still relevant since the shelf-life of drying technologies is rather long—several decades! However, I believe we have covered most of the commonly used drying equipment and ancillaries, as well as addressed industrial sectors where drying is a key operation.

In this edition for the first time we have covered several new topics relevant to drying, e. We have also covered new and emerging drying technologies in adequate detail. This book is organized in much the same way as the earlier editions. The main difference is the wider coverage of topics. Once again, a deliberate attempt is made to cover most industrial sectors and make the content useful to industry as well as academia.

Students and instructors in many disciplines will find the content useful for teaching, design, and research. It is particularly useful for researchers who wish to make their findings relevant to real-world needs. As energy costs escalate and environmental impact becomes a serious issue in the coming decade, it is clear that the significance of drying for industry will rise.

It is hoped that industry will encourage academia to include the study of drying, both as a basic and as an applied subject, as an essential part of engineering and technical curricula. Industry—university cooperation and active collaboration is essential to gaining in-depth knowledge of drying and dryers. Although no truly disruptive drying technology appears on the horizon today, it is likely to happen within the next decade.

This book addresses some of the new technologies that have the potential to be disruptive. Production of a massive handbook such as this one is a collective effort of scores of dedicated and enthusiastic individuals from around the globe. Indeed, this book embodies a result of globalization.

Purnima Mujumdar, as usual, played a pivotal part in bringing this project to a successful closure. Without her enthusiastic volunteer effort it is highly unlikely this book would have seen the proverbial end of the tunnel.

A number of my postgraduate students at McGill, National University of Singapore, and indeed many overseas institutions also assisted in various ways for which I want express my gratitude. The encouragement I received regularly from Dr.

I thank the authors for their patience and effort in making this third edition a valuable reference work. Mujumdar Singapore Editor Arun S.

Mujumdar is currently professor of mechanical engineering at the National University of Singapore, Singapore, and adjunct professor of chemical as well as agricultural and biosystems engineering at McGill University, Montreal, Canada.

Until , he was professor of chemical engineering at McGill. He earned his B. He has worked on experimental and modeling projects involving almost all physical forms of wet products to be dried in at least 20 different drying configurations, many of which were his original ideas that were later carried forward by others.

He has supervised over 40 Ph. Mujumdar has won numerous international awards and honors for his distinguished contributions to chemical engineering in general, and to drying as well as heat and mass transfer in particular. He is also the editor of over 50 books including the widely acclaimed Handbook of Industrial Drying Marcel Dekker, New York now undergoing third enhanced edition.

Mujumdar has lectured in 38 countries across 4 continents. He has also given professional development courses to industrial and academic audiences in the United States, Canada, Japan, China, and India.

Details of his research activities and interests in drying can be found at www. He has been instrumental in developing the then-neglected field of drying into a major multiand interdisciplinary field on a truly global scale. Thanks to his missionary efforts, often carried out single-handedly before the field received worldwide recognition, engineers and scientists around the world have been able to pursue their interests in this exciting field, which provides a kaleidoscope of challenging research opportunities for innovation.

He is aptly called the Drying Guru—a label he was first given during the presentation of the esteemed Joseph Janus Medal of the Czech Academy of Sciences in Prague in to honor his countless contributions to chemical engineering and drying technologies.

Jones EA Technology Ltd. Capenhurst, United Kingdom Rami Y. Anne de Bellevue, Quebec, Canada M. Schiffmann R. Schiffmann Associates, Inc. Wimberger Spooner Industries Inc. Maroulis, G. Saravacos, and Arun S. Mujumdar 11 Freeze Drying Athanasios I. Mujumdar 15 Impingement Drying Arun S. Jayas 22 Drying of Fish and Seafood M. Jayaraman and D. Sablani and Arun S. Carr, H.

Hung, Richard J. Wimberger, and Arun S. Mujumdar 41 Drying of Polymers Arun S. Pilosof and Virginia E. Jumah and Arun S. Markowski and Arun S. Jumah, Arun S. Mujumdar, and Vijaya G. Moisture held in loose chemical combination, present as a liquid solution within the solid or even trapped in the microstructure of the solid, which exerts a vapor pressure less than that of pure liquid, is called bound moisture.

Moisture in excess of bound moisture is called unbound moisture. When a wet solid is subjected to thermal drying, two processes occur simultaneously: 1. Transfer of energy mostly as heat from the surrounding environment to evaporate the surface moisture 2.

Transfer of internal moisture to the surface of the solid and its subsequent evaporation due to process 1 The rate at which drying is accomplished is governed by the rate at which the two processes proceed.

Energy transfer as heat from the surrounding environment to the wet solid can occur as a result of convection, conduction, or radiation and in some cases as a result of a combination of these effects. Industrial dryers differ in type and design, depending on the principal method of heat transfer employed. In most cases heat is transferred to the surface of the wet solid and then to the interior. However, in dielectric, radio frequency RF , or microwave freeze drying, energy is supplied to generate heat internally within the solid and flows to the exterior surfaces.

Process 1, the removal of water as vapor from the material surface, depends on the external conditions of temperature, air humidity and flow, area of exposed surface, and pressure. Process 2, the movement of moisture internally within the solid, is a function of the physical nature of the solid, the temperature, and its moisture content.

In a drying operation any one of these processes may be the limiting factor governing the rate of drying, although they both proceed simultaneously throughout the drying cycle. In the following sections we shall discuss the terminology and some of the basic concepts behind the two processes involved in drying. The separation operation of drying converts a solid, semisolid, or liquid feedstock into a solid product by evaporation of the liquid into a vapor phase through application of heat.

In the special case of freeze drying, which takes place below the triple point of the liquid that is removed, drying occurs by sublimation of the solid phase directly into the vapor phase. Phase change and production of a solid phase as end product are essential features of the drying process. Drying is an essential operation in the chemical, agricultural, biotechnology, food, polymer, ceramics, pharmaceutical, pulp and paper, mineral processing, and wood processing industries. Drying is perhaps the oldest, most common and most diverse of chemical engineering unit operations.

Over types of dryers have been reported whereas over distinct types are commonly available. It competes with distillation as the most energy-intensive unit operation due to the high latent heat of vaporization and the inherent inefficiency of using hot air as the most common drying medium. The latter figures have been obtained recently based on mandatory energy audit data supplied by industry and hence are more reliable.

Thus, the major costs for dryers are in their operation rather than in their initial investment costs. Drying of various feedstocks is needed for one or several of the following reasons: need for easy-tohandle free-flowing solids, preservation and storage, reduction in cost of transportation, achieving desired quality of product, etc. In many processes, improper drying may lead to irreversible damage to product quality and hence a nonsalable product.

Product size may range from microns to tens of centimeters in thickness or depth Product porosity may range from 0 to Operating pressure may range from fraction of a millibar to 25 atm Heat may be transferred continuously or intermittently by convection, conduction, radiation, or electromagnetic fields Clearly, no single design procedure that can apply to all or even several of the dryer variants is possible.

It is therefore essential to revert to the fundamentals of heat, mass and momentum transfer coupled with knowledge of the material properties quality when attempting design of a dryer or analysis of an existing dryer. Mathematically speaking, all processes involved, even in the simplest dryer, are highly nonlinear and hence scale-up of dryers is generally very difficult.

Handbook of Industrial Drying, Third Edition. Still the Most Complete, Up-To-Date, and Reliable Reference in the Field Drying is a highly energy-intensive operation and is encountered in nearly all industrial sectors. With rising energy costs and consumer demands for higher quality dried products, it is increasingly important to be aware of the latest developments in industrial.

Handbook of Industrial Drying. Handbook of Industrial Drying, Fourth Edition. By far the most commonly encountered and energy-intensive unit operation in almost all industrial sectors, industrial drying continues to attract the interest of scientists, researchers, and engineers. The Handbook of Industrial Drying, Fourth Edition not only delivers a comprehensive treatment of the current state of the art, but also serves.