Table of Contents

Cover

Title Page

About the Authors

Opening Remark

Preliminary Remarks

Preface

Chapter 1: Basics of Fire and Explosion: Risk Assessment

1.1 Basic Considerations on Fire and Explosion ( T1)
1.2 Explosive Atmosphere
1.3 Hybrid Mixtures ( P7)
1.4 Allocation of Explosion-Endangered Areas and Permissible Equipment ( P6)
1.5 Permissible Equipment (Equipment Protection Level)
1.6 Ignition Sources
1.7 Minimum Ignition Energy (MIE)
1.8 Imaginary Experiment to Assess the Hazardous Potential of Flammable Liquids
PowerPoint Presentations
References

Chapter 2: Principles of Static Electricity

2.1 Basics
2.2 Electrostatic Charging of Solids ( T2)
2.3 Triboelectric Series
2.4 Surface Resistivity
2.5 Electrostatic Charging of Liquids ( T2, T8)
2.6 Charging by Gases
2.7 Electric Field
2.8 Electric Induction ( T3)
2.9 Capacitance and Capacitor
PowerPoint Presentations
References

Chapter 3: Metrology

3.1 Basics ( T7)
3.2 Appropriate Metrology for Electrostatic Safety Measures
3.3 Comparison: Electrostatics/Electrical Engineering
3.4 Selecting the Suitable Measurement Methods
3.5 Assignment and Summary
3.6 Conductivity of Liquids
3.7 Bulk Materials
3.8 Concerning the Use of Insulating Material in Endangered Areas
3.9 Measurement of Electrostatic Charges
3.10 Other Measurement Applications
3.11 Capacitance
3.12 Themes around Air Humidity
PowerPoint Presentations
Picture Credits
References

Chapter 4: Gas Discharges

4.1 Mechanisms of Gas Discharges ( T5)
4.2 Electrostatic Gas Discharges
4.3 Types of Gas Discharges
4.4 Consequences of Gas Discharges
4.5 Listing of Traces Caused by Gas Discharges ( P11; T8)
4.6 How Can Dangerous Gas Discharges Be Avoided?
PowerPoint Presentations
Video Credits
References

Chapter 5: Preventing Electrostatic Disturbances

5.1 Electrostatics: When Sparks Fly
5.2 Dielectric Strength
5.3 Discharging Charged Surfaces
5.4 Potential Hazards Posed by Discharge Electrodes
Picture Credits
Video Credits
References
Further Reading

Chapter 6: Description of Demonstration Experiments

6.1 Preliminary Remarks
6.2 Static Voltmeter
6.3 Field Meter
6.4 Van de Graaff Generator
6.5 Explosion Tube
6.6 Electrostatic Force Effects
6.7 Charges Caused by Separating Process
6.8 Charging of Particles
6.9 Electric Induction
6.10 Dissipating Properties
6.11 Experiments with the Explosion Tube
6.12 Gas Discharges
6.13 Fire and Explosion Dangers
Reference

Chapter 7: Case Studies

7.1 Strategy of Investigation
7.2 Ignitions Due to Brush Discharges
7.3 Case Studies Related to Propagating Brush Discharges
7.4 Case Histories Related to Spark Discharges
7.5 Ignition Caused by Cone Discharges
7.6 Doubts with Electrostatic Ignitions
7.7 Act with Relevant Experience
PowerPoint Presentations
Video
References

Chapter 8: Targeted Use of Charges

8.1 Applications
8.2 Examples of the Creative Implementation of Applications
8.3 Summary
Picture Credits
Video Credits
References

Chapter M: Mathematics Toolbox

M1 Energy W of a Capacitance
M2 Field E; Field Strength E⃗
M3 Flux Density D⃗ (Earlier: Dielectric Displacement)
M4 Frequency f
M5 Inductance L
M6 Capacitance C
M7 Force F,
M8 Charge Q
M9 Potential ϕ
M10 Voltage U
M11 Resistance R (Universal)

Annex

1 Videos for download from www.wiley-vch.de
2 PowerPoint Presentations

Index

End User License Agreement

List of Illustrations

Chapter 1: Basics of Fire and Explosion: Risk Assessment

Figure 1.1 Danger triangle.
Figure 1.2 Vapor pressure/temperature curve of ethanol.
Figure 1.4 Minimum ignition energy subject to the stoichiometric ratio.
Figure 1.3 System of flammable liquids (up to 2009).
Figure 1.5 Correlation between flash point and λ − 1 – condition.

Chapter 2: Principles of Static Electricity

Figure 2.1 Opposite charges attract each other and like charges repel each other.
Figure 2.2 Charge dissipation.
Figure 2.3 Charging before contact.
Figure 2.4 Charging by contact.
Figure 2.5 Charging by contact and subsequent separation.
Figure 2.6 Triboelectric series.
Figure 2.7 Median of charges at a separating speed of 1 m/s.
Figure 2.8 Surface resistivity ρ_s (Ω) of various plastics at 50% RH and 23 °C.
Figure 2.9 Correlation of surface resistivity ρ_s and air humidity.
Figure 2.10 Nonconductive liquid in metal vessel.
Figure 2.11 Charged ions are dragged along with the liquid flow.
Figure 2.12 Electrical field lines in a parallel plate capacitor.
Figure 2.13 Electric field lines (solid) between parallel conductive plates in combination with equipotential lines (dashed).
Figure 2.14 Electric field lines in a cylinder–plate configuration combined with equipotential lines.
Figure 2.15 Practical utilization of field lines (solid) and equipotential lines (dashed).
Figure 2.16 Sequence of electric induction.
Figure 2.17 Charged particle establishes image charge at a conductive object.
Figure 2.18 Isolated screw charged by electric induction.

Chapter 3: Metrology

Figure 3.1 Measurement of leakage resistance at flooring
Figure 3.2 Performance and result of a walking
Figure 3.3 Influencing factors for electrical resistance.
Figure 3.4 Guard ring circuit for fault prevention when measuring the volume resistance.
Figure 3.5 Common electrode configuration for surface resistance.
Figure 3.6 Guard ring circuit for fault prevention when measuring the surface resistance.
Figure 3.7 Attracting forces (F) between charges of opposite polarity and repelling forces (F) between charges of like polarity.
Figure 3.8 Schematic diagrams of static voltmeters.
Figure 3.9 Electrometer amplifier.
Figure 3.10 Charge measurement by means of a Faraday pail.
Figure 3.11 Charge measurement on free-falling droplets, test rig, and resulting diagram.
Figure 3.12 Principle basic configuration of induction electric field meters (with permission of F7).
Figure 3.13 Electro field meter by Kleinwächter GmbH (with permission of F7).
Figure 3.14 Charge on unrolling foil.
Figure 3.15 Undistorted electrical field around a charged foil.
Figure 3.16 Field distortion when approaching an earthed measuring device (with permission of F2).
Figure 3.17 Field homogenizing on one side (with permission of F2).
Figure 3.18 Homogenizing of the electric field on both sides of the foil (with permission of F2).
Figure 3.19 Measuring error caused by earthed parts (wooden desk) nearby (with permission of F2).
Figure 3.20 Measuring error caused by earthed parts (metal roller) nearby (with permission of F2).
Figure 3.21 Principle of Kasuga Denki KSD System (with permission of F3).
Figure 3.22 Block diagram of surface voltmeter (with permission of F3).
Figure 3.23 Measurement of field strength by means of potential adaption.
Figure 3.24 Principle of piezo technology for potential-free measurement (with permission of F4).
Figure 3.25 Trek contact voltmeter (with permission of F5).
Figure 3.26 Measuring area E-field meter Ø 20 mm (with permission of F1).
Figure 3.27 Measuring area piezo sensor (with permission of F5).
Figure 3.28 Induction electric field meter modified as a voltmeter (with permission of F2).
Figure 3.29 Voltmeter up to ±40 kV (precision ±2.5%) (with permission of F7).
Figure 3.30 Modified induction electric field meter as a Coulomb meter (with permission of F2).
Figure 3.31 Modified ball electrode.
Figure 3.32 Electric induction field meter as a picoampere meter (with permission of F2).
Figure 3.33 Measurement of surface charge on a moving web (with permission of F2).
Figure 3.34 Test procedure with triboelectric charge [9]. (a: fixed clamping unit; b: field intensity meter; c: cylinder rods; d: test sample; e: guide rail; f: tensioning device; g: slide start position).
Figure 3.35 Test procedures with electrostatic influence (with permission of F2).
Figure 3.36 Front view of ICM-2 by the Saxony Textile Research Institute e.V. (STFI) (with permission of F6).
Figure 3.37 Charged plate monitor (with permission of F7).
Figure 3.38 Charged plate monitor with earthed plate (with permission of F7).
Figure 3.39 Configuration of the paper test procedure as defined by Knopf [6] (with permission of F2).
Figure 3.40 Measurement configuration for charging bulk material (with permission of F2).
Figure 3.41 Electrostatic charging on filling the tank (with permission of F2).
Figure 3.42 Measurement of electrostatic charges in a spray tower (with permission of F2).
Figure 3.43 Block diagram of a capacitance meter.
Figure 3.44 The voltage curve of the measured object (see Section M10.3).
Figure 3.45 Charge decay measurement as defined by Künzig (with permission of F2).
Figure 3.46 Charge decay measuring device QUMAT^®-528 (with permission of F16).
Figure 3.47 Air temperature versus dew point at parameter RH.
Figure 3.48 Dew point hygrometry (with permission by F8).
Figure 3.49 Psychrometer.
Figure 3.50 Principle of LiCl moisture detector.

Chapter 4: Gas Discharges

Figure 4.1 Gas discharge between ball electrodes.
Figure 4.2 Partial plasma effect with gas discharge.
Figure 4.3 Photo of a gas discharge with partial plasma.
Figure 4.4 Collapsing of electric and magnetic fields bring about a radio signal.
Figure 4.5 Grounded emitter.
Figure 4.6 Loop dipole.
Figure 4.7 Spark discharging of a capacitor.
Figure 4.8 Principle of corona discharging.
Figure 4.9 Principle of brush discharging.
Figure 4.10 Cone discharge in a silo (1: super charged bulk material, 2: conductive silo, earthed, 3: cone discharges).
Figure 4.11 Bipolar charged foil.
Figure 4.12 Charging by striking particles (shielded).
Figure 4.13 Charging by striking particles (unshielded).
Figure 4.14 Propagating brush discharge (with permission of F9).
Figure 4.15 Spark at a liquid surface (V4.2).
Figure 4.16 Enamel coatings with conductive layer. Comment of this example: Pfaudler BE6300 reactor with 20 m² glass-lined surface. (1) Electrostatic energy discharges from the process into the earthed reactor body. (2) Electrostatic charge migrates through the cover coat by capacitance without damaging. (3) Electrostatic charge is then spread over the large surface of the conductive glass layer. (4) The 1 mm cover coat is not penetrated, thus preventing the lining from being damaged. (5) External earthing of the conductive layer removes any electrical potential difference . Charging/discharging time of capacitor with (with permission of F10).
Figure 4.17 Occurrences of different gas discharges.

Chapter 5: Preventing Electrostatic Disturbances

Figure 5.1 Charge-emitting discharge electrode (with permission of F2
Figure 5.2 Clean and corroded points (with permission of F2).
Figure 5.3 Passive ionizers (earthing chain/earthing tongues) (with permission of F2).
Figure 5.4 Passive ionizer with capacitive coupling (with permission of F2).
Figure 5.5 Illustration of field line concentration for the ionization of the air (with permission of F2).
Figure 5.6 The charge profile is made visible – Lichtenberg Figure (lycopodium on plexiglass).
Figure 5.7 Triboelectric effect from contact and separation (with permission of F2).
Figure 5.8 Propagating brush discharge during the rerolling process (with permission of F23).
Figure 5.9 Discharge electrode over the delta film web reel (with permission of F2).
Figure 5.10 Optimal discharging setup during unwinding/rewinding (with permission of F2).
Figure 5.11 Optimal placement of discharge bars (with permission of F2).
Figure 5.12 Single-sided discharging – unfavorable (with permission of F2).
Figure 5.13 Double-sided discharging – optimal (with permission of F2).
Figure 5.14 Bipolar layers of equal field strength (with permission of F2).
Figure 5.15 Disrupting the bipolar field strengths of equal height permits discharging (with permission of F2).
Figure 5.16 Example 1 of multilayer material.
Figure 5.17 Example 2 of multilayer material.
Figure 5.18 Ionization blower head used to increase separation rate (Eltex R55 shown in image) (with permission of F2).
Figure 5.19 Discharging on sheeting machinery (with permission of F2).
Figure 5.20 Discharge electrode with a large effective range (with permission of F11).
Figure 5.21 The “CombiCleaner” operating principle (with permission of F12).
Figure 5.22 Ionization blower head on a handling system (with permission of F2).
Figure 5.23 Rotary nozzle with discharge electrode for hazardous areas (ATEX approved) [4] (with permission of F2).
Figure 5.24 Discharging electrodes on a set of weighing scales (with permission of F13).
Figure 5.25 Charge on granules (with permission of F2).
Figure 5.26 Paper disposal (with permission of F2).
Figure 5.27 Bulk transport (with permission of F2).
Figure 5.28 Discharging blower above a feeder bowl (with permission of F13).
Figure 5.29 Discharging above a feeder bowl (with permission of F2).
Figure 5.30 Discharge electrode with resistive and capacitive current limiter [6] (with permission of F2).
Figure 5.31 Dirty discharge electrodes that no longer function and that may have lost their ATEX approval (with permission of F2).
Figure 5.32 Bearing damage on a rolling bearing from a spark discharge.

Chapter 6: Description of Demonstration Experiments

Figure 6.1 Attentive dog.
Figure 6.2 Voltmeter.
Figure 6.3 Field meter.
Figure 6.4 Van de Graaff generator.
Figure 6.5 Explosion tube.
Figure 6.6 Rolling pipes – 1.
Figure 6.7 Rolling pipes – 2.
Figure 6.8 Rolling pipes – 3.
Figure 6.9 Hovering pipes – 1.
Figure 6.10 Hovering pipes – 2.
Figure 6.11 Electroscope.
Figure 6.12 Field lines.
Figure 6.13 Charging by separation – 1.
Figure 6.14 Charging by separation – 2.
Figure 6.15 Charging by separation – 3.
Figure 6.16 Charging of single particles in metal pipe.
Figure 6.17 Charging of single particles in PTFE pipe.
Figure 6.18 Charging of many particles.
Figure 6.19 Basic experiment on induction.
Figure 6.20 Chimes.
Figure 6.21 Plastic vessel with shielding.
Figure 6.22 Glass apparatus.
Figure 6.23 Checking on dissipating properties.
Figure 6.24 Charged person causes sparks.
Figure 6.25 Ignition voltage.
Figure 6.26 Spark discharges.
Figure 6.27 Corona discharges.
Figure 6.28 Brush discharges.
Figure 6.29 Brush discharges in a fluorescent lamp.
Figure 6.30 Evidence of ion wind.
Figure 6.31 Propagating brush discharges – 1.
Figure 6.32 Propagating brush discharges – 2.
Figure 6.33 Ignition of dust.
Figure 6.34 Short circuit of a double-layer charge.
Figure 6.35 Demonstration of a propagating brush discharge at a double-layer charge.
Figure 6.36 Demonstration of flash point.
Figure 6.37 Concentration gradient.
Figure 6.38 Progressive flame front.
Figure 6.39 Oxygen demand – 1.
Figure 6.40 Oxygen demand – 2.
Figure 6.41 Gasification process with wood.

Chapter 7: Case Studies

Figure 7.1 Emptying PE-bag.
Figure 7.2 Plastic inner liner.
Figure 7.3 Sieving machine.
Figure 7.4 Spray-bed-dryer.
Figure 7.5 Discharges on creeping oil film. (V4.2)
Figure 7.6 Throttle valve.
Figure 7.7 Filling n-hexane.
Figure 7.8 Hose filter.
Figure 7.9 Fire in water hose.
Figure 7.10 Lost shovel in a silo.
Figure 7.11 Fire in PE-drum.
Figure 7.12 Terminal box (opened).
Figure 7.13 Incoming sunbeam.

Chapter 8: Targeted Use of Charges

Figure 8.1 Charge emitting charging bars
Figure 8.2 The distribution of forces in opposite- and similar-poled charges [1].
Figure 8.3 Load on a plate capacitor
Figure 8.4 Fixing of decorative films/decorative papers to plates
Figure 8.5 Illustration showing the fixing of paper on a metal band
Figure 8.6 Ply blocking of chipboard
Figure 8.7 Fixing of coverings on an MDF plate (medium-density fiberboard)
Figure 8.8 Blocking systems [3].
Figure 8.9 Charging with plate electrodes (example: Stack blocker AVN VB 70, Affeldt Maschinenbau GmbH, www.affeldt.com).
Figure 8.10 Schema and implementation for the adhesion of an insert on a variable base
Figure 8.11 Ribbon charging by the charging bars
Figure 8.12 Melt layer adhesion using a wire electrode on a chill roll
Figure 8.13 Melt layer adhesion by edge zone fixing (point charging) on the chill roll (anti-neck-in)
Figure 8.14 Anti-neck-in with charging bar (Eltex ATR23), film 12 µm at 600 m/min.
Figure 8.15 Avoiding telescoping when winding using electrostatic charging
Figure 8.16 Core dummy charge
Figure 8.17 Direct charge using electrodes
Figure 8.18 Indirect charge
Figure 8.19 Oil application on metal sheets
Figure 8.20 Aerosols are misted from the laminar air boundary layer (V8.4, with permission of F2).
Figure 8.21 Aerosols are attracted from the charged web
Figure 8.22 Heat and material transport on a web
Figure 8.23 Breakup of a laminar airflow as described by F. Knopf
Figure 8.24 Gravure printing and coating machines with electrostatic assistance
Figure 8.25 Schematic diagram of a coating machine [5]. Key: 1, drying system; 2, impression cylinder; 3, ionizing bar; 4, powerful brush discharge; 5, low brush discharge (without No. 3: powerful brush discharge); 6, coating unit (zone 0 with highly flammable liquids); 7, winding systems (unwinder/rewinder); 8, dust; 9, floor; dissipative in Zone 1.
Figure 8.26 Coating machine with print cylinders with different diameters
Figure 8.27 Variable coverings to reduce the escape of ink particles
Figure 8.28 Highly charged ink particles deposited in the electrical field (Lichtenberg deposits)
Figure 8.29 Schematic diagram of ink deposits in the electrical field
Figure 8.30 Ink deposits glow
Figure 8.31 Ink particle deposits
Figure 8.32 Five roller coating system (example).
Figure 8.33 Misting tacker as described by F. Knopf
Figure 8.34 Operating principle of the Optical-Web-Tension-Profile-Scanner.
Figure 8.35 Results of a web tension profile measurement
Figure 8.36 Material separation.
Figure 8.37 Example of the operating principle of an electrostatic precipitator
Figure 8.38 Low-energy plasma on a double pin array
Figure 8.39 Device for precipitating impurities from a stream of gas
Figure 8.40 Principle of operation of Grabit’s electroadhesion technology (with permission of F20).
Figure 8.41 Corona system with ceramic electrodes that have been extracted
Figure 8.42 Grafting of organic groups on the surface of polymer film
Figure 8.43 Configuration of active discharging electrodes after a corona system.

List of Tables

Chapter 1: Basics of Fire and Explosion: Risk Assessment

Table 1.1 Threshold of oxygen concentration for some gases and dusts with two kinds of inert gases (volume percent oxygen).
Table 1.2 Criteria for flammable liquids.
Table 1.3 Flammable liquids, classification, and labeling.
Table 1.4 Relationship between zone, category, and EPL.
Table 1.5 Classification of combustible gases into temperature classes.
Table 1.6 Classification of combustible gases into explosion groups.
Table 1.7 Increase of surface by fragmentation.
Table 1.8 Exemplary liquids.
Table 1.9 Minimum ignition energy (MIE) correlating with minimum ignition charge (MIQ) [4].

Chapter 2: Principles of Static Electricity

Table 2.1 Liquids of low conductivity (relaxation time in seconds).
Table 2.2 Liquids of medium conductivity (relaxation time in milliseconds).
Table 2.3 Liquids of high conductivity (relaxation time in microseconds).

Chapter 3: Metrology

Table 3.1 Comparison between electrical engineering and electrostatics.
Table 3.2 Criteria for the selection of the measuring voltage.
Table 3.3 Assignment of resistance values.
Table 3.4 Conductivity values of selected liquids.
Table 3.5 Liquids of low conductivity.
Table 3.6 Liquids of high conductivity.
Table 3.7 Groups of bulk materials.
Table 3.8 Charge build up on powders.
Table 3.9 Permittivity ε_r.
Table 3.10 Temperature and saturation.
Table 3.11 Humidity calibration solutions.

Chapter 4: Gas Discharges

Table 4.1 Boundary limits for the characterization of solid materials and examples for the classification of objects.
Table 4.2 Maximum allowed isolated capacitance in equipment for zones with explosive atmosphere.
Table 4.3 Restriction on size of insulating solid materials in hazardous areas.
Table 4.4 Maximum accepTable transferred charge.
Table 4.5 Influences for gas discharge.
Table 4.6 Ignition potential of electrostatic gas discharges.

Chapter 5: Preventing Electrostatic Disturbances

Table 5.1 Restriction on size of insulating solid materials in hazardous areas [5].

Chapter 7: Case Studies

Table 7.1 Ignition sources.
Table 7.2 Alternative restrictions on insulating solid materials and isolated conductive or dissipative parts in hazardous areas for equipment within the scope of IEC/TS 60079-0:2011 [5]

Chapter 8: Targeted Use of Charges

Table 8.1 Impact of misting tacker.

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About the Authors

Günter Lüttgens was born in Berlin, 1933, and holds a master’s degree in electrical engineering. Since graduation he mainly worked in the chemical industry in the field of electrostatics. He was primarily responsible for laboratory research, as well as plant safety, in the area of fire and explosion prevention. In 1998, he was nominated by IEC as an expert for electrostatic test methods. For more than 25 years he gave lectures on static electrification and safety measures together with his wife Sylvia. He published several articles and specialist books. In 2013, he received the International Fellow Award by the European Working Party (EFCE) as a researcher and teacher in the field of “Static Electricity in Industry.”

Sylvia Lüttgens was born in Geroda, 1946, was graduated a teacher, and tried to direct the interest of her students to Music and English. Then she learned about static electrification and that it could be the cause for many a fire or an explosion. So she has been working together with her husband Günter, carrying out experimental lectures (up to 2015) in seminars about electrostatics, giving practical proof of the theory. Besides, she is publishing articles and writing specialist books on this topic.

They actually compiled the first encyclopedia on static electricity 15 years ago, and the third edition was published in 2013.

Wolfgang Schubert was born in 1952. He studied print technology in Leipzig and is a trained printer. He became self-employed in 1997 having previously worked in various managerial roles in the print industry and in sales and marketing for manufacturers of roll- and sheet-fed printing presses. Since then he has also been working in the specialized field of electrostatics, in sales and marketing and also in further education. He has coauthored the specialist publication Static Electricity.

In May 2016, he was publicly appointed and inaugurated by the Leipzig Chamber of Commerce and Industry (IHK) as an expert in the fields of printing processes, printing presses, printability, runnability, and packaging printing. He also works as an expert in the field of electrostatics.

Opening Remark

Minds of Felix – our faithful companion

May I introduce myself; I am Felix the electrostatics specialist dog (see Figure 6.1 in Section 6). When my humans are carrying out seminars, I silently lie under the tables with the experimental devices until Sylvia prepares the one in which a plastic tumbler is flung into the air by an explosion in an explosion tube (see Section 6.11.1). Then, I run for the tumbler and noisily chew it apart, which makes the audience laugh.

When my humans Sylvia and Günter are working at the computer, I often lie on the sofa watching them. When I have had enough of it, I fetch my teddy and place it in front of them. Then, they throw it somewhere, and I have to find it. This happens several times but then I take my teddy and jump back onto the sofa again. My humans think I am doing this because I am bored, but this is not true! I feel sorry for them that they have to sit in front of the computer with lots of paper, clattering the keys, writing this specialist book. So I have to offer them some variety. I know what this is all about, and I am definitely responsible for my pack.

Diagram showing the four paw prints of a cat.

Preface

It gives me a great pleasure to preface this excellent reference book for engineers and technicians. Sylvia Lüttgens, Günter Lüttgens and Wolfgang Schubert are well known for their very didactic manuals, excellent presentations and so well prepared demonstrations such way that rather complicate phenomena seem simple.

This reference book on Electrostatic Hazards for engineers and technicians is, in my knowledge, the first one with very clear explanations, describing step by step the phenomenon with very didactic concepts and perfect pedagogic demonstrations.

Electrostatic Hazard is a very worrying problem in a lot of industrial processes, using liquids, granular material, powders, or foils etc. It concerns a wide range of industries: Chemical, Petroleum, Pharmaceutical industry, as well as the agricultural sector and electric power plants.

Indeed, in recent decades many industrial processes increasingly use electrically insulating materials. These materials such as polymers have emerged with the petroleum products industry and have played a growing importance in industry because of their lower costs like metals and their easier processing, manufacturing and use. This has partly led to the fact that these materials and products brought about electrostatic hazards and nuisances and have become an important concern. When speaking about electrostatics, everyone has in mind the spark which we sometimes feel by touching the door of a car after being parked; or small pieces of paper attracted to a plastic wall that has been rubbed before. In fact, electrostatic charging in general is the study of electrical phenomena when the charges are not moving (“static”). However, at present, the so-called electrostatic phenomena are those involving electrification processes whereby often charge accumulation due to the use of insulating materials and product takes place.

The electrostatic hazards are sources of dangers of electric discharges due to electrostatic phenomena. Under certain conditions, these discharges lead to ignitions causing fire or explosions. Electrostatic nuisances cause degradation of an industrial process due to electrostatic effects. Precondition for this is that the generated charge will be accumulated.

Charge generation is, in principle, related to contact of material and separation thereafter as, e.g., friction, flow, transfer of solids, or liquids. The accumulation is the result of the storage or collection of such products or liquids in unearthed containers.

Unfortunately electrostatic hazards may result in fatal accidents, injuries, often serious, especially burns, property damage, often important or significant in that case, for example, of fire extension to nearby facilities.

This reference book has a very logical and scientific methodology, making these interrelations very clear and useful for engineers and technicians. Indeed, it starts with the situations with the Risk Assessment, explaining precisely when and where such risks come into being. Then the basics of Static Electricity are presented, developing all the concepts and equations which are needed to understand the different phenomena. In another chapter the metrology, needed to understand the different situations, is presented. The processes of the different gas discharges are then exposed as well as different methods to prevent electrostatic disturbances. One important subject of the book is the presentation of very didactic descriptions of demonstration experiments and of case studies.

It would fall short of that goal to hold static electricity accountable only for dangers and nuisances, however, electrostatic mechanisms are used in many applications where one would not expect them as there are: photocopying techniques, car body lacquering etc. Widely used is static electricity in improvements of many different scopes of application like wetting, drying, printing etc. Therefore one chapter is dedicated especially to that task to motivate the curious reader to improve other technologies with the help of static electricity.

Finally a very useful mathematic toolbox is given at the end of the book, making an easy understanding of all equations needed to comprehend the different processes.

Each chapter provides a complete bibliography of what was stated.

And in the good end, I have spent a pleasant time to read this very educational and didactic reference book that I strongly recommend to any engineer and technician who wants to learn on Electrostatics.

Prof. em. Gerard Touchard
University Poitiers,
Groupe Electrofluidodynamique
[Institute PPRIME]
Poitiers, France
October 2016

Understanding, Controlling, Applying