Engineering principles

This section examines and reviews some of the basic principles diat engineers and sciendsts employ in performing design calculations mid predicting die performance of plant equipment. Topics include die tlicrmochemistry, chemical reacdon equilibrimii, chemical kinedcs, die ideal gas law, pardal pressure, pliase equilibrimii, and die Reynolds Number. These basic principles will assist die reader in acquiring a better miderslmidiiig of some of the material diat appears later in die book. 

The heal of reaction (see Section 4.4) is defined as tlie enthalpy change of a system undergoing chemical reaction. If the retictants and products are at tlie same temperature and in their standard states, tlie heat of reaction is temied tlie standard lieat of reaction. For engineering purposes, the standard state of a chemical may be taken as tlie pure chemical at I atm pressure. Heat of reaction data for many reactions is available in tlie literature.  

Witli regard to chemical reactions, two important questions arc of concern to the engineer  

Chemical themiodynamics provides tlie answer to tlie first question however, it provides information about tlie second. Reaction rates fall witliin tlie domain of chemical kinetics and are treated later in tliis section. Both equilibrium and kinetic effects must be considered in an overall engineering analysis of a chemical reaction. 

Chemical reaction equilibrium calculations are structured around another thermodynamic term called tlie free energy. Tliis so-callcd free energy G is a property that also cannot be defined easily without sonic basic grounding in tlicmiodynamics. However, no such attempt is made here, and the interested reader is directed to tlie literature. Note that free energy has the same units as entlialpy and internal energy and may be on a mole or total mass basis. Some key equations and information is provided below. 

The following equation is used to calculate tlie chemical reaction equilibrium constant K at a temperature T. 

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The high-field output of laser devices allows for a wide variety of nonlinear interactions [17] between tire radiation field and tire matter. Many of tire initial relationships can be derived using engineering principles by simply expanding tire media polarizability in a Taylor series in powers of tire electric field ... 

Known engineering principles must be appHed even in areas of extremely dilute concentration. 

J. E. Bailey and D. F. Ohis, Biochemical Engineering Fundamentals, 2nd ed. McGraw-HiU Book Co., Inc., New York, 1986. A very good treatise describing the apphcation of basic engineering principles to fermentation technology. 

M. Loncin and R. L. Merson, Food Engineering—Principles and Selected Applications, Academic Press, Inc., New York, 1979, 494 pp. 

Monitoring by Electromechanical Instrumentation. According to basic engineering principles, no process can be conducted safely and effectively unless instantaneous information is available about its conditions. AH sterilizers are equipped with gauges, sensors (qv), and timers for the measurement of the various critical process parameters. More and more sterilizers are equipped with computerized control to eliminate the possibiUty of human error. However, electromechanical instmmentation is subject to random breakdowns or drifts from caUbrated settings and requires regular preventive maintenance procedures. 

Lime-Sulfuric. Recovery of citric acid by calcium salt precipitation is shown in Figure 3. Although the chemistry is straightforward, the engineering principles, separation techniques, and unit operations employed result in a complex commercial process. The fermentation broth, which has been separated from the insoluble biomass, is treated with a calcium hydroxide (lime) slurry to precipitate calcium citrate. After sufficient reaction time, the calcium citrate slurry is filtered and the filter cake washed free of soluble impurities. The clean calcium citrate cake is reslurried and acidified with sulfuric acid, converting the calcium citrate to soluble citric acid and insoluble calcium sulfate. Both the calcium citrate and calcium sulfate reactions are generally performed in agitated reaction vessels made of 316 stainless steel and filtered on commercially available filtration equipment. 

G. Prentice, Electrochemical Engineering Principles, Prentice-HaH, Inc., Englewood Cliffs, N.J., 1991. 

FIG. 25-71 Vents used to control tlie lateral movement of gases in landfills, (a) Cell, (h) Barrier, (c) Well. From G. Tchohanoglous, H. Theisen, and R. Eliassen, Solid Wastes Engineering Principles and Management Issues, McGraw-Hill, New Yor k, 1977. )... 

A key success factor for reducing the costs and lead times for vehicle manufacturers, for example, is the degree of integration of the suppliers within the product development process. This is seen as a natural extension to concurrent engineering principles (Wyatt et al., 1998). For many years, in engineering companies, a substantial proportion of the finished product, typically two thirds, consists of components or subassemblies produced by suppliers (Noori and Radford, 1995). 

Spirits manufacturing is a sophisticated technology, but in general process operations are less complex and demanding as in the case of oil refinery operations. Often the technology may be described as being closer to an art as opposed to an exact science, but clearly engineering principles for distillation, filtration and batchwise type operations are meticulously employed. 

The chemical industry represents a 455-billion-dollar-a-year business, with products ranging from cosmetics, to fuel products, to plastics, to pharmaceuticals, health care products, food additives, and many others. It is diverse and dynamic, with market sectors rapidly expanding, and in turmoil in many parts of the world. Across these varied industry sectors, basic unit operations and equipment are applied on a daily basis, and indeed although there have been major technological innovations to processes, many pieces of equipment are based upon a foundation of engineering principles developed more than 50 years ago. 

The objective of this chapter is to provide an overview of filtration terminology and basic engineering principles, as well as calculation methods that describe the filtration process in a generalized way. The basis equations describing the generalized process of filtration have been around for nearly 100 years, and with few refinements, continue to be applied to modem design practices. 

This book is designed as a handy desk reference covering fundamental engineering principles of project planning schemes and layout, corrosion principles and materials properties of engineering importance. It is intended as a general source of typical materials property data, useful for first pass materials selection in process design problems. 

Progelhof, R.C. and Throne, J.L. Polymer Engineering Principles, Hanser, New York (1993)... 

In designing the process and equipment, use chemical engineering principles to minimize the accumulation of energy or materials and to contain the energy and materials ... 

Heinsohn, Robert lennines. Industrial Ventilation Engineering Principles, lohn Wilev Sons. New York, NY, 1991. 

R. J. Heinsohn. Industrial Ventilation Engineering Principles. New York John Wiley N Sons, 1991. 

Following a brief section on Units and Dimensions (Section 4.2), Sections 4.3 and 4.4 review some of the key physical and chemical properties, respectively. Three important conservation laws are presented in Section 4.5. Basic engineering principles are discussed in Section 4.6, to present a foundation for the theory underlying the proper design and operation of a chemical process. 

This chapter primarily serves as a review of process fundamentals such as units, dimensions, chemical and physical properties, conservation laws, and engineering principles. 

Engineering calculations predict emission rates without tlie use of emission factors. These calculations use basic science and engineering principles, chemical property data, and operating conditions to provide a detailed analysis of the emissions for a specific process. Tliis is a more sophisticated approach tluui emission factors, and is useful for evaluating various operational and control alteniatives. 

Z. Tadmor and I. Klein, Engineering Principles of Plasticating Extuder, Van Nostrand, New York, p. 349 (1970). 

Two-stroke diesel cycle engine principle of operation. 

Rabia, H., Oilwell Drilling Engineering Principles and Practices, Graham and Trotman Ltd, 1985. 

In the majority of cases common sense, combined with basic engineering principles, should be sufficient to ensure good service from the tower on a continuous basis. The reputable supplier will always be ready to help and advise. If the advice is sought in time, many of the problems associated with the changes mentioned need never arise. 

Doran, P.M., Bioprocess Engineering Principles . Academic Press, New York, 1995. 

Nielsen, J. and Villadsen, J., Bioreaction Engineering Principles . New York Plenum Press, 1994, pp. 229 135. 

Refining and applying chemical engineering principles to the design and control of the chemical reactors in which devices are fabricated. 

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