Industrial food processing involves the production of added value foods on a large scale; these foods are made by mixing and processing different ingredients in a prescribed way. The food industry, historically, has not designed its processes in an engineering sense, i.e. by understanding the physical and chemical principles which govern the operation of the plant and then using those principles to develop a process. Rather, processes have been 'designed' by purchasing equipment from a range of suppliers and then connecting that equipment together to form a complete process. When the process being run has essentially been scaled up from the kitchen then this may not matter. However, there are limits to the approach. . As the industry becomes more sophisticated, and economies of scale are exploited, then the size of plant reaches a scale where systematic design techniques are needed. . The range of processes and products made by the food industry has increased to include foods which have no kitchen counterpart, such as low-fat spreads. . It is vital to ensure the quality and safety of the product. . Plant must be flexible and able to cope with the need to make a variety of products from a range of ingredients. This is especially important as markets evolve with time. . The traditional design process cannot readily handle multi-product and multi-stream operations. . Processes must be energetically efficient and meet modern environmen­ tal standards.

Inhalt

1 Introduction to process design.- 1.1 Material requirements and flows.- 1.2 Energy balances.- 1.3 Process economics.- Appendix 1.A: Some basic definitions.- Conclusions.- Further reading.- 2 Newtonian fluid mechanics.- 2.1 Laminar and turbulent flow.- 2.2 Ideal fluids.- 2.3 Laminar flows.- 2.4 Dimensional analysis.- 2.5 Turbulent flow.- Conclusions.- Further reading.- 3 Introduction to heat transfer.- 3.1 Heat conduction.- 3.2 Heat transfer in flowing systems.- 3.3 Heat exchange: more practical aspects.- Conclusions.- Further reading.- 4 Mass transfer in food and bioprocesses.- 4.1 Why does transfer occur?.- 4.2 Mechanisms.- 4.3 Equilibrium.- 4.4 Diffusion.- 4.5 Transient behaviour.- 4.6 Flowing systems.- 4.7 Interphase transfer.- 4.8 Aeration.- 4.9 Mass transfer limitations.- Conclusions.- Further reading.- 5 Food rheology.- 5.1 Characteristics of non-Newtonian fluids.- 5.2 Viscometric flows.- 5.3 Application to engineering problems.- Appendix 5.A: Linear viscoelastic Maxwell element.- Appendix 5.B: Concentric cylinder viscometer.- Appendix 5.C: Cone and plate viscometer.- Conclusions.- References and further reading.- 6 Process design: heat integration.- 6.1 Design of process plant.- 6.2 Second-law analysis: heat integration.- 6.3 Heat and process integration in the food industry.- Conclusions.- 7 Process control.- 7.1 What is the control problem?.- 7.2 Block diagrams.- 7.3 Process dynamics.- 7.4 multiple inputs and linearization.- 7.5 Frequency response.- 7.6 Feedforward and feedback control.- 7.7 Types of controller action.- 7.8 Control system design for complete plants.- Conclusions.- Further reading.- 8 Reactors and reactions in food processing.- 8.1 Reactor types.- 8.2 Physical chemistry of food reactions.- 8.3 Analysis of isothermal 'ideal' reactor systems.- 8.4 Non-isothermal reactions.- 8.5 Non-ideal flow and mixing in continuous reactors.- Conclusions.- References and further reading.- 9 Thermal treatment of foods.- 9.1 Engineering principles.- 9.2 Continuous processing: problems and solutions.- 9.3 Fouling and cleaning in food process plant.- Conclusions.- References and further reading.- 10 Mixing in food processing.- 10.1 Fundamentals of mixing.- 10.2 Fluid-mixing equipment.- 10.3 Power consumption in stirred tanks.- 10.4 Miscible liquid blending operations.- 10.5 Gas-liquid mixing.- 10.6 Liquid-liquid dispersions and the creation of emulsions.- 10.7 Solids suspension and solid-liquid mass transfer.- 10.8 Scale-up of mixers from pilot trials.- 10.9 Alternative mixing devices.- 10.10 Mixing of particulate materials.- Conclusions.- References and further reading.- 11 Process design: an exercise and simulation examples.- 11.1 An integrated cheese plant: a design exercise.- 11.2 Computer simulations.- Conclusions.- Overall conclusions.