A model of combined boiling and evaporation of liquid films on horizontal tubes was developed. Specifically, this work was directed toward developing a heat transfer model applicable to the design of horizontal tube falling film evaportors for OTEC. The heat transfer process is modelled as combined boiling and evaporation of the liquid film. In modelling the behavior of single tubes special account is taken of heat transfer in the initial thermal developing region of the film. Predictions were found to agree favorably with the published experimental data for boiling and evaporation of thin water films on single horizontal tubes. The predicted upper and lower limits of heat transfer for ammonia on a vertical bank of plain horizontal tubes are 5.4 kW/m2-K and 3.1 kW/m2-K, respectively. The upper limit will be approached when the influence of between-tube evaporation and turbulence created by the liquid falling from one tube to the next are important. For an OTEC evaporator with plain tubes, the upper and lower limits of the overall U are 2.33 kW/m2-K and 1.82 kW/m2-K, respectively. With ammonia-side boiling enhancement, the overall U can be increased to about 3.8 kW/m2-K.

Heat and mass transfer is the core science for many industrial processes as well as technical and scientific devices. Automotive, aerospace, power generation (both by conventional and renewable energies), industrial equipment and rotating machinery, materials and chemical processing, and many other industries are requiring heat and mass transfer processes. Since the early studies in the seventeenth and eighteenth centuries, there has been tremendous technical progress and scientific advances in the knowledge of heat and mass transfer, where modeling and simulation developments are increasingly contributing to the current state of the art. Heat and Mass Transfer - Advances in Science and Technology Applications aims at providing researchers and practitioners with a valuable compendium of significant advances in the field.

Engineering students in a wide variety of engineering disciplines from mechanical and chemical to biomedical and materials engineering must master the principles of transport phenomena as an essential tool in analyzing and designing any system or systems wherein momentum, heat and mass are transferred. This textbook was developed to address that need, with a clear presentation of the fundamentals, ample problem sets to reinforce that knowledge, and tangible examples of how this knowledge is put to use in engineering design. Professional engineers, too, will find this book invaluable as reference for everything from heat exchanger design to chemical processing system design and more. * Develops an understanding of the thermal and physical behavior of multiphase systems with phase change, including microscale and porosity, for practical applications in heat transfer, bioengineering, materials science, nuclear engineering, environmental engineering, process engineering, biotechnology and nanotechnology * Brings all three forms of phase change, i.e., liquid vapor, solid liquid and solid vapor, into one volume and describes them from one perspective in the context of fundamental treatment * Presents the generalized integral and differential transport phenomena equations for multi-component multiphase systems in local instance as well as averaging formulations. The molecular approach is also discussed with the connection between microscopic and molecular approaches * Presents basic principles of analyzing transport phenomena in multiphase systems with emphasis on melting, solidification, sublimation, vapor deposition, condensation, evaporation, boiling and two-phase flow heat transfer at the micro and macro levels * Solid/liquid/vapor interfacial phenomena, including the concepts of surface tension, wetting phenomena, disjoining pressure, contact angle, thin films and capillary phenomena, including interfacial balances for mass, species, momentum, and energy for multi-component and multiphase interfaces are discussed * Ample examples and end-of-chapter problems, with Solutions Manual and PowerPoint presentation available to the instructors

This long awaited second edition of a popular textbook has a simple and direct approach to the diversity and complexity of food processing. It explains the principles of operations and illustrates them by individual processes. The new edition has been enlarged to include sections on freezing, drying, psychrometry, and a completely new section on mechanical refrigeration. All the units have been converted to SI measure. Each chapter contains unworked examples to help the student gain a grasp of the subject, and although primarily intended for the student food technologist or process engineer, this book will also be useful to technical workers in the food industry