Kurzfassung: 1 An overview of pneumatic conveying systems and performance -- 1.1 Introduction -- 1.2 Why pneumatic conveying? -- 1.3 What can be conveyed? -- 1.4 What constitutes a pneumatic conveying system? -- 1.5 Modes of pneumatic conveying -- 1.6 Basic pneumatic conveying systems -- 1.7 Further classification techniques -- 1.8 Description and operation of a pneumatic conveying system -- 1.9 Putting it all together -- 1.10 An overview -- 1.11 Some useful conversion factors and tables -- References -- 2 Single phase flow in pneumatic conveying systems -- 2.1 Introduction -- 2.2 Definitions -- 2.3 Perfect gas laws -- 2.4 Drying of compressed air -- 2.5 The compression process -- 2.6 Gas flow through pipes -- 2.7 Illustrative examples -- References -- 3 Fluid and particle dynamics -- 3.1 Introduction -- 3.2 Law of continuity -- 3.3 Drag on a particle -- 3.4 Equations for calculation of relevant properties -- 3.5 Fluidization characteristics of powders -- References -- 4 Fundamentals -- 4.1 Introduction -- 4.2 Forces acting on a single particle in an air stream -- 4.3 Particle size -- 4.4 Shape -- 4.5 Dynamic equations -- 4.6 Terminal velocity -- 4.7 Single particle acceleration -- 4.8 Centrifugal flow -- 4.9 Slip velocity in a gravitational field -- 4.10 Multiple particle systems -- 4.11 Voidage and slip velocity -- 4.12 Frictional representations -- 4.13 Acceleration and development regions -- 4.14 Particle distribution in pneumatic conveying -- 4.15 Compressibility effect not negligible -- 4.16 Speed of sound in gas—solid transport -- 4.17 Gas—solid flow with varying cross-sectional area -- 4.18 Branching arrangements -- 4.19 Bend analysis -- 4.20 Downward sloping particle flow -- 4.21 Dense phase transport -- 4.22 Estimation of pressure drop in slugging dense phase conveying -- 4.23 Estimation of pressure drop in non-slugging dense phase conveying -- 4.24 Plug flows -- 4.25 Worked examples -- References -- 5 Flow regimes in vertical and horizontal conveying -- 5.1 Introduction -- 5.2 Choking versus non-choking system in vertical flow -- 5.3 Choking system in vertical flow -- 5.4 Non-choking system in vertical flow -- 5.5 Particle segregation in vertical pneumatic transport -- 5.6 Saltation in horizontal conveying -- References -- 6 Principles of pneumatic conveying -- 6.1 Introduction—putting it all together -- 6.2 The state diagram revisited -- 6.3 Methods for scaling-up -- 6.4 Use of theoretical models and definitions -- 6.5 Additional pressure drop factoz (?z) -- 6.6 Pressure drop -- 6.7 Some important functional relationships -- 6.8 Sequence to be followed to obtain the system pressure loss (?p) -- References -- 7 Feeding of pneumatic conveying systems -- 7.1 Introduction and overall design philosophy -- 7.2 Classification of feeding systems -- 7.3 Feeder selection criteria -- 7.4 Low pressure feeding devices -- 7.5 Medium pressure feeding systems -- 7.6 High pressure feeding devices -- 7.7 Conclusions -- References -- 8 Flow in standpipes and gravity conveyors -- 8.1 Introduction—standpipes and gravity conveyors -- 8.2 Classification of standpipe systems -- 8.3 Classification of flow modes in a standpipe -- 8.4 Equations pertaining to each flow mode -- 8.5 Flow through a valve -- 8.6 Stability of standpipe flow -- 8.7 Analysis of industrial standpipes—case studies -- 8.8 Gravity conveyors -- References -- 9 An overview of high pressure systems including long distance and dense phase pneumatic conveying systems -- 9.1 Introduction -- 9.2 High pressure systems -- 9.3 Dense phase flow classification -- 9.4 A description of plug flow and the relationships between plug flow and material characteristics -- 9.5 System selection and product characteristics -- 9.6 Dense phase system design -- 9.7 Long distance pneumatic conveying and pressure loss minimization -- 9.8 Conclusions -- References -- 10 Gas—solids separation -- 10.1 Introduction -- 10.2 Selection criteria -- 10.3 Cyclone separators—theory of the separation of particles in the centrifugal field -- 10.4 Fabric filters -- 10.5 Cleaning by sound -- 10.6 Conclusions -- References -- 11 Some comments on: the flow behaviour of solids from silos; wear in pneumatic conveying systems; ancillary equipment -- 11.1 Introduction -- 11.2 The flow of solids from bins -- 11.3 Flow aid devices for silos and hoppers -- 11.4 Wear in pneumatic conveying systems -- 11.5 Ancillary equipment -- 11.6 Conclusions -- References -- 12 Control of pneumatic transport -- 12.1 Basic material flow and control theory -- 12.2 Transport lags -- 12.3 Analysis of gas—solid flow by transfer functions -- 12.4 Stability of pneumatic transfer systems -- 12.5 Stability analysis with Taylor series linearization -- 12.6 Linear stability analysis—Jackson approach -- 12.7 Stability via the Liapunov analysis -- References -- 13 Instrumentation -- 13.1 Standard instrumentation -- 13.2 Transducers -- 13.3 Cross-correlation procedures -- 13.4 A Coriolis force meter -- 13.5 Dielectric meter -- 13.6 Load cells -- 13.7 Particle tagging -- 13.8 Electrostatic based meters -- 13.9 Acoustic measurements -- 13.10 Screw conveyors -- 13.11 Light measuring devices -- 13.12 Other techniques for particle velocities -- 13.13 Instrumentation for industrial applications -- References -- 14 System design and worked examples -- 14.1 Introduction -- 14.2 Moisture content in air -- 14.3 The design of industrial vacuum systems -- 14.4 Dilute phase pneumatic conveying system design (method 1) -- 14.5 Dilute phase pneumatic conveying system design (method 2) -- 14.6 Dilute phase pneumatic conveying system design (method 3) -- 14.7 Dense phase pneumatic conveying system design -- 14.8 Test yourself—dilute phase calculations -- 14.9 Gas—solid flow examples -- 14.10 Conclusions -- References.

Kurzfassung: When the four of us decided to collaborate to write this book on pneumatic conveying, there were two aspects which were of some concern. Firstly, how could four people, who live on four different continents, write a book on a fairly complex subject with such wide lines of communications? Secondly, there was the problem that two of the authors are chemical engineers. It has been noted that the majority of chemical engineers who work in the field of pneumatic conveying research have spent most of their time considering flow in vertical pipes. As such, there was some concern that the book might be biased towards vertical pneumatic conveying and that the horizontal aspects (which are clearly the most difficult!) would be somewhat neglected. We hope that you, as the reader, are going to be satisfied with the fact that you have a truly international dissertation on pneumatic conveying and, also, that there is an even spread between the theoretical and practical aspects of pneumatic conveying technology.

Kurzfassung: 1 Principles of transduction -- Underlying physical principles of transducers -- Silicon technology -- Summary -- Review questions -- Further reading -- Problems -- 2 Sensors, actuators and displays -- Mechanical sensing -- The synchro -- Temperature sensing -- Radiation detection transducers -- Optical sensors -- Sonic transducers -- Nuclear radiation detectors -- Chemical activity -- Actuators, stepper motors and displays -- Summary -- Review questions -- Further reading -- Problems -- 3 Analogue processing of signals -- The ideal operational amplifier -- The practical operational amplifier -- Chopper stabilization -- Modulation -- The analogue multiplexer or scanner -- Summary -- Review questions -- Further reading -- Problems -- 4 Signal convertion -- The digital-to-analogue converter -- The analogue-to-digital converter -- Sample-and-hold circuits -- Voltage-to-frequency conversion -- Synchro-to-digital conversion -- The phase lock loop -- Summary -- Review questions -- Further reading -- Problems -- 5 Digital processing of signals -- Filtering in the digital domain -- Sampling -- Quantization -- Signal averaging -- Linerarization of sensor response -- Digital processing circuits -- The digital signal processor -- Summary -- Review questions -- Further reading -- 6 Interfacing -- Digital circuitry -- Specialized interfacing chips -- Transfers of data over greater distances -- Interfacing standards -- Summary -- Review questions -- Further reading -- Appendix A -- Solutions to problems.

Kurzfassung: -~- ~_vane \::y;) \ c:=::J ] 0=0 ] Dc:=JD Fig. 2. 39 Seven-segment devices for large displays and good visibility at up to 300 m can readily be obtained. Summary The number of transducer types is almost unlimited, and in order to bring our area of study down to a more manageable size we have considered transduc­ ers under four main headings. Input transducers for detecting mechanical change allow us to sense force, pressure, position, proximity, displacement, velocity, acceleration, vibration and shock in all their multiple manifestations. The basis of many mechanical sensors is the strain gauge which is usually used in a bridge configuration. Other devices such as the L VDT and synchro are also widely used. Temperature transducers form another large group, and we have looked at the operating principles of the major types, with some of the techniques used in compensating for non-ideal characteristics. Radiation and chemical sensing transducers form the remaining groups. Actuators rely almost entirely on electromagnetic action and, in modern equipment, occur most commonly as solenoids and relays, including the reed relay, and stepper motors. Visual displays also come in a bewildering range of types and sizes, but, because of their ease of interfacing with electronic circuitry, the majority are based on the LED and LCD. Review questions 1. What is meant by gauge factor? 2. Define Young's modulus. 3.

Kurzfassung: 1. Agar -- 2. Alginates -- 3. Carrageenans -- 4. Casein -- 5. Egg Protein Gels -- 6. Gellan Gum -- 7. Gelatine -- 8. Mixed Polymer Gels -- 9. Muscle Proteins -- 10. Pectin -- 11. Whey Proteins.

Kurzfassung: The food technologist who wishes to produce a gelled product is faced with two basic options for achieving the desired effect; whether to use a protein or a polysaccharide. Although a gel can be formed by either a protein or a polysaccharide, the resultant gels have different characteristics: • Polysaccharide gels are characterised by their fine texture and transparency which is achieved at a low polymer concentration. They can be formed by heating and cooling, pH adjustment or specific ion addition . • Protein gels are characterised by a higher polymer concentration (5-10%) and are formed almost exclusively by heat denaturation. Before reaching a final decision, the technologist must take a number of factors into consideration. The purpose of this book is to help the technologist in his choice by providing fundamental practical information, in one book, on the properties of gels (and factors which influence them) for both types of biopolymer. To help the reader, each chapter is (wherever possible) organised in the same way so that, for example, information on structure will always be available in section 2. The examples in the Applications section of each chapter are not meant to be exhaustive, but to illustrate the various ways in which the particular polymer can be used to form a gelled product.

Kurzfassung: 1 Sampling of powders -- 2 Sampling of dusty gases in gas streams -- 3 Sampling and sizing from the atmosphere -- 4 Particle size, shape and distribution -- 5 Sieving -- 6 Microscopy -- 7 Interaction between particles and fluids in a gravitational field -- 8 Dispersion of powders -- 9 Incremental methods of particle size determination -- 10 Cumulative methods of sedimentation size analysis -- 11 Fluid classification -- 12 Centrifugal methods -- 13 The electrical sensing zone method of particle size distribution determination (the Coulter principle) -- 14 Radiation scattering methods of particle size determination -- 15 Permeametry and gas diffusion -- 16 Gas adsorption -- 17 Other methods for determining surface area -- 18 Determination of pore size distribution by gas adsorption -- 19 Mercury porosimetry -- 20 On-line particle size analysis -- Problems -- Appendix 1 Equipment and suppliers -- Appendix 2 Manufacturers’ and suppliers’ addresses -- Author index.

Kurzfassung: Powder technology is a subject in its own right, and powder characterization is central to an understanding of this discipline. In the eight years since the printing of the third edition of Particle Size Measurement there have been two big changes in my life. After thirty years of academia I have returned to industry, and after a lifetime in Great Britain I have emigrated to the United States. In industry the initial demand is to relate powder properties to product performance and then to maintain powder consistency. This requires on-line or rapid off-line analysis which, in turn, has led to the demand for a whole range of new instruments whose primary function is process monitoring. Historically, chemical engineering courses have concentrated on the be­ haviour of fluids, and engineers enter industry relatively unschooled in the subject of powder behaviour . Yet, when my colleagues Reg Davies and John Boughton surveyed three thousand Dupont products, they discovered that 80% involved powder at some stage of their manufacture. The results of this survey illustrate the need for more training in this key subject. This edition reflects the changing image of powder characterization towards in-process size analysis. Hence the chapter covering on-line analysis has been largely re-written. Apart from this, I have expanded certain sections and describe the new instruments that have been introduced since the last edition.

Kurzfassung: 1 Introduction -- 2 General Properties of Feedback Amplifiers -- 3 Amplifiers Without Feedback -- 4 Feedback Amplifier Circuits -- 5 More About Feedback Amplifiers -- 6 The Op. Amp. — Basic Ideas and Circuits -- 7 Op. Amp. Non-idealities -- 8 Selected Op. Amp. Applications -- 9 Further Op. Amp. Applications -- Appendix: Steady-State Network Analysis using Phasors and Complex Variables -- Answers to Numerical Problems.

Kurzfassung: Feedback circuits in general, and op. amp. applications which embody feedback principles in particular, playa central role in modern electronic engineering. This importance is reflected in the undergraduate curriculum where it is common practice for first-year undergraduates to be taught the principles of these subjects. It is right therefore that one of the tutorial guides in electronic engineering be devoted to feedback circuits and op. amps. Often general feedback circuit principles are taught before passing on to op. amps., and the order of the chapters reflects this. It is equally valid to teach op. amps. first. A feature of the guide is that it has been written to allow this approach to be followed, by deferring the study of Chapters 2, 4 and 5 until the end. A second feature of the guide is the treatment of loading effects in feedback circuits contained in Chapter 5. Loading effects are significant in many feedback circuits and yet they are not dealt with fully in many texts. Prerequisite knowledge for a successful use of the guide has been kept to a minimum. A knowledge of elementary circuit theory is assumed, and an under­ standing of basic transistor circuits would be useful for some of the feedback circuit examples.

Kurzfassung: 1. The Mechanism of Antioxidant Action in vitro -- 2. Detection, Estimation and Evaluation of Antioxidants in Food Systems -- 3. Chemistry and Implications of Degradation of Phenolic Antioxidants -- 4. Natural Antioxidants Exploited Commercially -- 5. Natural Antioxidants not Exploited Commercially -- 6. Biological Effects of Food Antioxidants -- 7. Toxicological Aspects of Antioxidants Used as Food Additives.

Kurzfassung: Antioxidants are present naturally in virtually all food commodities, providing them with a valuable degree of protection against oxidative attack. When food commodities are subjected to processing, such natural antioxidants are often depleted, whether physically, from the nature of the process itself, or by chemical degradation. In conse­ quence, processed food products usually keep less well than do the commodities from which they originated. Ideally, food producers would like them to keep better. This objective can often be achieved by blending natural products rich in antioxidants with processed foods, or by using well recognised antioxidants as food additives. In order to understand their action, and hence to apply antioxidants intelligently in food product formulation, some knowledge of the mechanisms by which they function is necessary. This is complex and of antioxidative may rely on one or more of several alternative forms intervention. Accordingly, the various mechanisms that may be relevant are discussed in Chapter 1, in each case including the 'intervention' mechanism. When present in, or added to, foods antioxidants are functional in very small quantities, typically, perhaps, at levels of 0·01 % or less.