This book is written primarily for an audience of engineers who design, specify, procure, update, and maintain mixers in the processing industries. It is an ap­ plication-oriented handbook to support the design and operation of mixers for liquids, liquids and solids, liquids and gases, and any combination thereof. This book does not address solids mixing. Mixing applications are identified as either flow controlling or shear rate controlling, and are addressed as such. Specific mixing applications and design parameters are presented for blending, solid suspension, heat transfer, mass transfer, dispersions, extractions, etc. Fundamentals of mixer design and operation, agitation applications spec­ trum, types and geometries of mixing impellers, etc. are presented in Chapter I, providing the basis for practical information presented in subsequent chapters. Flow controlled mixing applications are discussed in Chapter 2. These include blending, solid suspension, heat transfer, dissolving of solids, and crys­ tallization. Optimization of mixer design is emphasized, with an eye to saving power and capital cost. Also discussed is the use of draft tube circulator mixers to optimize mixer performance and cost. Shear controlled mixing applications are addressed in Chapter 3. These include gas-liquid dispersions, mass transfer, fermentation, emulsions, extrac­ tions, and dispersions of solids in liquids. Chapter 4 focuses on geometric and nongeometric scaleup of mixers to ac­ complish equal or better mixing results in various scales of volume. Scaleup relevant to applications of blending, solids suspension, and mass and heat transfer is explained.