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공개·회원 9명
John Jackson
John Jackson

A Comprehensive Guide to Unit Operations in Chemical Engineering: Principles of Unit Operations 2nd Ed by Foust et al.



- Who are the authors of the book "Principles of Unit Operations" and what are their credentials? - What are the main topics covered in the book and how are they organized? H2: Stage Operations - What are mass transfer operations and how do they involve equilibrium stages? - How to perform equilibrium stage calculations for binary and multicomponent systems? - What are countercurrent multistage operations and how to design them with or without reflux? - What are some simplified calculation methods for multistage operations? H2: Molecular and Turbulent Transport - What are the molecular transport mechanisms of mass, heat, and momentum? - How to apply differential and integral balances to transport problems? - What are the equations of change for transport phenomena? - What is turbulent transport and how to model it? - What are the fundamentals of transfer coefficients and interphase transfer? H2: Applications to Equipment Design - How to apply heat transfer principles to design heat exchangers, condensers, evaporators, etc.? - How to apply mass transfer principles to design absorption, distillation, extraction, etc.? - How to analyze simultaneous heat and mass transfer problems such as humidification, drying, evaporation, and crystallization? - How to apply the energy balance to flow systems and fluid motive devices? - How to handle particulate solids and their flow and separation through fluid mechanics? H1: Conclusion - What are the main takeaways from the book "Principles of Unit Operations"? - How does the book help chemical engineers to understand and solve practical problems in their field? - What are some limitations or challenges of the book and how can they be overcome or improved? H1: FAQs - Q1: What is the difference between unit operations and unit processes? - Q2: What are some examples of unit operations in different industries? - Q3: What are some advantages and disadvantages of using simplified calculation methods for multistage operations? - Q4: What are some factors that affect the choice of heat transfer equipment? - Q5: What are some applications of simultaneous heat and mass transfer in food processing? # Article with HTML formatting Introduction




Unit operations are the basic steps or techniques used in chemical engineering to transform raw materials into products. They involve physical changes such as separation, mixing, heating, cooling, etc., without altering the chemical composition of the substances involved. Unit operations are essential for designing, analyzing, and optimizing chemical processes and plants. They also help chemical engineers to understand the underlying principles of transport phenomena, thermodynamics, kinetics, and reaction engineering.




principles of unit operations 2nd ed foust



One of the most influential books on unit operations is "Principles of Unit Operations" by Alan S. Foust, Leonard A. Wenzel, Curtis W. Clump, Louis Maus, and L. Bryce Andersen. The book was first published in 1955 and has been revised several times since then. The second edition was published in 1980 and is still widely used as a reference text by students and professionals alike. The authors of the book are all distinguished professors or researchers in chemical engineering who have made significant contributions to their field.


The book covers a wide range of topics related to unit operations, such as stage operations, molecular and turbulent transport, and applications to equipment design. The book is organized into four parts: Part I deals with stage operations such as mass transfer operations, phase relations, equilibrium stage calculations, countercurrent multistage operations, etc.; Part II deals with molecular and turbulent transport such as molecular transport mechanisms, differential and integral balances, equations of change, turbulent transport mechanisms, etc.; Part III deals with applications to equipment design such as heat transfer, mass transfer, simultaneous heat and mass transfer problems, energy balance in flow systems, fluid motive devices, etc.; Part IV deals with particulate solids such as flow and separation through fluid mechanics. The book also includes numerous examples, problems, tables, figures, and references to help the reader understand and apply the concepts and methods presented.


Stage Operations




Stage operations are unit operations that involve the transfer of mass or energy between two or more phases that are in contact with each other. Examples of stage operations are distillation, absorption, extraction, leaching, adsorption, etc. These operations are based on the concept of equilibrium stages, which are hypothetical zones where the phases are in equilibrium with each other. The number of equilibrium stages required to achieve a desired separation or conversion depends on the operating conditions, the properties of the phases, and the design of the equipment.


The book explains how to perform equilibrium stage calculations for binary and multicomponent systems using various methods such as graphical, algebraic, and numerical methods. The book also shows how to design countercurrent multistage operations with or without reflux using the McCabe-Thiele method, the Ponchon-Savarit method, the Lewis-Matheson method, etc. The book also discusses some simplified calculation methods for multistage operations such as the Fenske-Underwood-Gilliland method, the Kremser-Brown method, the Edmister method, etc. These methods are useful for estimating the number of stages or the minimum reflux ratio without solving rigorous equations.


Molecular and Turbulent Transport




Molecular and turbulent transport are unit operations that involve the transfer of mass, heat, or momentum within a single phase or between different phases due to molecular or turbulent motion. Examples of molecular and turbulent transport are diffusion, conduction, convection, radiation, viscosity, drag, etc. These operations are governed by the principles of transport phenomena, which describe how matter and energy move from one location to another under the influence of various driving forces.


The book explains how to apply differential and integral balances to transport problems involving mass, heat, or momentum transfer. The book also derives the equations of change for transport phenomena using the conservation laws of mass, energy, and momentum. The book also introduces the concept of turbulent transport and how to model it using various approaches such as Reynolds averaging, eddy viscosity models, mixing length models, etc. The book also discusses the fundamentals of transfer coefficients and interphase transfer such as mass transfer coefficients, heat transfer coefficients, Sherwood number, Nusselt number, etc. These coefficients are useful for correlating experimental data and predicting transport rates in different situations.


Applications to Equipment Design




Applications to equipment design are unit operations that involve the design and analysis of various types of equipment used in chemical processes and plants. Examples of equipment design are heat exchangers, condensers, evaporators, absorbers, distillation columns, extraction columns, dryers, crystallizers, pumps, compressors, valves, pipes, etc. These equipment are designed to perform specific functions such as heating, cooling, separating, mixing, drying, evaporating, crystallizing etc., while satisfying certain criteria such as efficiency, effectiveness capacity etc.


The book explains how to apply heat transfer principles to design heat exchangers such as shell-and-tube heat exchangers plate heat exchangers etc., using various methods such as LMTD method NTU method etc. The book also explains how to apply mass transfer principles to design absorption distillation extraction etc., using various methods such as graphical algebraic numerical etc. The book also analyzes simultaneous heat and mass transfer problems such as humidification drying evaporation crystallization etc., using various methods such as psychrometric charts drying curves evaporation diagrams crystallization maps etc. The book also applies the energy balance to flow systems and fluid motive devices such as pumps compressors valves pipes etc., using various methods such as Bernoulli's equation head loss equation power equation efficiency equation etc.


Particulate Solids




Particulate solids are unit operations that involve the handling and processing of solid particles or granular materials in chemical processes and plants. Examples of particulate solids are crushing grinding screening sieving filtration sedimentation centrifugation cyclone separation fluidization mixing agglomeration pelletization etc. These operations are based on the principles of fluid mechanics which describe how fluids (liquids or gases) interact with solid particles under different conditions.


Particulate Solids




Particulate solids are unit operations that involve the handling and processing of solid particles or granular materials in chemical processes and plants. Examples of particulate solids are crushing, grinding, screening, sieving, filtration, sedimentation, centrifugation, cyclone separation, fluidization, mixing, agglomeration, pelletization, etc. These operations are based on the principles of fluid mechanics which describe how fluids (liquids or gases) interact with solid particles under different conditions.


The book explains how to handle particulate solids and their flow and separation through fluid mechanics using various methods such as Stokes' law, drag coefficient, terminal velocity, Reynolds number, friction factor, pressure drop, Darcy's law, Kozeny-Carman equation, settling velocity, hindered settling, batch and continuous sedimentation, centrifugal force, cyclone efficiency, minimum fluidization velocity, bed expansion, pressure drop across a fluidized bed, filtration rate and cake resistance, cake washing and drying, pneumatic and hydraulic conveying, etc. The book also discusses how to mix particulate solids and how to form them into desired shapes and sizes using methods such as random and ordered mixing, segregation and de-mixing, mixing index and time, power consumption of mixers, granulation and coalescence mechanisms, nucleation and growth models, breakage and attrition models, pelletization methods and equipment, etc.


Conclusion




The book "Principles of Unit Operations" by Foust et al. is a comprehensive and authoritative text on the fundamentals and applications of unit operations in chemical engineering. The book covers a wide range of topics related to stage operations, molecular and turbulent transport applications to equipment design and particulate solids The book provides clear explanations numerous examples problems tables figures and references to help the reader understand and apply the concepts and methods presented.


The book helps chemical engineers to understand and solve practical problems in their field by providing them with the necessary tools and techniques for designing analyzing and optimizing chemical processes and plants. The book also helps chemical engineers to integrate different unit operations into a coherent whole and to evaluate their performance and efficiency. The book also helps chemical engineers to develop critical thinking creative problem-solving and communication skills that are essential for their profession.


The book has some limitations or challenges that can be overcome or improved by further research or development. For example the book assumes ideal or simplified conditions for some unit operations that may not reflect the reality of complex or non-ideal systems. The book also does not cover some emerging or advanced topics such as nanofluids microfluidics membrane separation etc., that may have significant applications in chemical engineering. The book also does not include some modern tools or software that can facilitate the learning or application of unit operations such as computational fluid dynamics (CFD) process simulation optimization etc.


FAQs




Q1: What is the difference between unit operations and unit processes?


A1: Unit operations are physical changes that do not alter the chemical composition of the substances involved such as separation mixing heating cooling etc. Unit processes are chemical changes that alter the chemical composition of the substances involved such as reaction oxidation reduction etc.


Q2: What are some examples of unit operations in different industries?


A2: Some examples of unit operations in different industries are distillation in petroleum refining absorption in gas purification extraction in pharmaceutical production drying in food processing evaporation in sugar production crystallization in salt production filtration in water treatment sedimentation in mineral processing fluidization in coal combustion mixing in polymer production pelletization in fertilizer production etc.


Q3: What are some advantages and disadvantages of using simplified calculation methods for multistage operations?


A3: Some advantages of using simplified calculation methods for multistage operations are that they are easy to apply require less data or information and give quick estimates or results. Some disadvantages of using simplified calculation methods for multistage operations are that they are less accurate less reliable and less generalizable than rigorous methods. They may also have some assumptions or limitations that may not be valid for some systems or situations.


Q4: What are some factors that affect the choice of heat transfer equipment?


A4: Some factors that affect the choice of heat transfer equipment are the type and properties of the fluids involved the required heat duty and temperature difference the available space and layout the capital and operating costs the maintenance and reliability the safety and environmental issues etc.


Q5: What are some applications of simultaneous heat and mass transfer in food processing?


A5: Some applications of simultaneous heat and mass transfer in food processing are drying of fruits vegetables grains etc., to preserve them and reduce their weight and volume; evaporation of milk juice syrup etc., to concentrate them and increase their shelf life; crystallization of sugar salt honey etc., to produce solid products with desired shapes and sizes; freezing of meat fish dairy products etc., to extend their storage life and prevent microbial growth; etc.


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