Fluidization of Fine Powders: Cohesive Versus Dynamical Aggregation

ISBN-13: 9789400755864 / Angielski / Twarda / 2012 / 136 str.

Jos Manuel Valverde Mill N.

Opis

This book covers the rich phenomenology exhibited by fine powders when they are fluidized by a gas flow. Fine powder cohesiveness leads to poor flowability, clumping, difficulty in fluidizing, irregular avalanching behavior, etc. Despite all the inconveniences, fine powder processes pervade the chemical, pharmaceutical, agricultural and mining industries among others. The author in this book analyzes the mechanism by which interparticle adhesive forces are reduced by means of surface additives. Different techniques have been developed in the last years to assist fluidization by helping the gas flow to mobilize and break cohesive aggregates, which help to homogenize fluidization. As reviewed in this book, the use of these techniques may have a relevant impact on novel processes based on fluidized beds of fine powder and with relevant applications on leading edge technologies such as Atomic Layer Deposition on nanoparticles and CO2 capture by gas-fluidized beds of adsorbent powders. The study of fluidized beds has a marked interdisciplinary character. This book is thus intended for academic and industrial researchers in applied physics, mechanical, chemical, and environmental engineering, who are interested in the special characteristics of fine powders."

Spis treści

Dedication.- Preface.- Acknowledgements.- Acronyms.- 1 Introduction. The classical Geldart’s diagram and the new type of gas-fluidization behavior.- 2 The structure of Geldart A gas-fluidized beds.- 3 Magnetic stabilization of fluidized beds of magnetizable particles.- 4 The fluidlike behavior of granular materials fluidized by liquids.- 5 The fluidlike behavior of some fine and ultrafine powders fluidized by gas.- 6 On the question of fluidlike fluidization stability.- 7 Dynamic aggregation of fine particles in gas-fluidized beds.- 8 The modified Geldart’s diagram.- 9 Fluidization of nanopowders.- 10 Effect of gas viscosity on the fluidization behavior of fine powders.- 11 Fluidlike fluidization as affected by external fields.- 12 The use of additives to control powder flow. Mechanical properties of fine powder beds.- 13 Fluidization assistance techniques.

O autorze

José Manuel Valverde Millán is Assistant Professor in the Department of Electronics and Electromagnetism, Faculty of Physics, University of Seville. He is an Associate Editor of the Journal of Nanoparticle Research. His research activity is interdisciplinary and lies between engineering and fundamental physics. A major contribution of his studies was the development of a novel powder tester, which earned him an award by Xerox Co.. He also received the Outstanding Researcher Award by the International Iberian Nanotechnology Laboratory- INL. He has authored 73 journal papers, 4 educational monographs, 5 patents.  He has carried out detailed studies on the fluidization and mechanical properties of fine powders. This work is aimed at formulating models for a deeper understanding of the special behaviour of powder systems. A main subject of his studies has been the development of synthetic powders with enhanced CO2 capture efficiency.

Blurb

This book will be mainly devoted to demonstrate the rich phenomenology exhibited by fine powders when they are fluidized by a gas flow. Fine powder cohesiveness leads to poor flowability, clumping, difficulty in fluidizing, irregular avalanching behavior, etc. Despite all the inconveniences, fine powder processes pervade the chemical, pharmaceutical, agricultural and mining industries among others. The author in this book analyzes the mechanism by which interparticle adhesive forces are reduced by means of surface additives. Different techniques have been developed in the last years to assist fluidization by helping the gas flow to mobilize and break cohesive aggregates, which help to homogenize fluidization. As reviewed in this book, the use of these techniques may have a relevant impact on novel processes based on fluidized beds of fine powder and with relevant applications on leading edge technologies such as Atomic Layer Deposition on nanoparticles and CO2 capture by gas-fluidized beds of adsorbent powders. The study of fluidized beds has a marked interdisciplinary character.  This book is thus intended for academic and industrial researchers in applied physics, mechanical, chemical, and environmental engineering, who are interested in the special characteristics of fine powders.