Electrostatic Hazards (eBook)

Front Cover 1
Electrostatic Hazards 4
Copyright Page 5
Contents 6
Foreword 10
Acknowledgements 12
Chapter 1. Danger of fire and explosion 14
1.1 Basic considerations 14
1.2 Conditions for ignition 14
1.3 Minimum ignition energy 20
1.4 Literature 26
Chapter 2. Origin of static electricity 27
2.1 Double layer charge 28
2.2 Charging of liquids and gases 32
2.3 Reducing the tendency of charging 33
2.4 Electrostatic induction 37
2.5 Basic concepts and units 41
2.6 Static charges on the clothing and the body 45
2.7 Literature 51
Chapter 3. Electrostatic discharges as sources of ignition 52
3.1 Definitions 52
3.2 Mechanisms of gas discharges 52
3.3 Types of gas discharge 53
3.4 Incendivity of gas discharges 66
3.5 Traces left by gas discharges 68
3.6 Literature 69
Chapter 4. Principles of safety 71
Chapter 5. Case histories related to brush discharges 75
5.1 Ignition in a heated tank containing diphenyl 75
5.2 Pouring flaked product into an agitator vessel 77
5.3 Filling pipe blocked with sulphur leading to the ignition of methanol 79
5.4 PE liner slipping out of a paper bag 80
5.5 Ignition caused by an antistatic PE bag 81
5.6 Impregnation of a glass fibre fabric 82
5.7 Shaking fine dust out of a PE bag 84
5.8 Ion exchanger resin in toluene 85
5.9 Pumping polluted toluene 86
Chapter 6.Case histories related to cone or bulking discharges 89
6.1 Plastic foam released from an autoclave 89
6.2 Dust explosion in a silo 90
Chapter 7. Case histories related to propagating brush discharges 92
7.1 Plastic tube used in the pneumatic conveying of powder 92
7.2 Plastic pipe used in the pneumatic conveying of powder 94
7.3 Plastic injector in a jet mill 95
7.4 PE liner in a metal drum 97
7.5 PE liner in a paper drum 99
7.6 Polymethylmethacrylate (PMMA) window pane in the silo of a granulating plant 100
7.7 PP coated expansion pipe 102
7.8 Plastic tank inside a metal mould 103
7.9 Literature 104
Chapter 8. Case histories related to spark discharges 105
8.1 Dusts 105
8.2 Rotating beater dryer (1) 105
8.3 Explosion of a resin powder in a metal drum 107
8.4 Dust removal from tablets 109
8.5 Filter bag with a supporting framework 110
8.6 Filter fabric containing interwoven steel fibres 112
8.7 Explosion when emptying a metal drum 114
8.8 Filter fabric made partially conducting by a flame- proofing agent 116
8.9 Emptying a tumble dryer 118
8.10 Cyclone separator set up on a drum 120
8.11 Fire caused by an antistatic PE bag 121
8.12 Pouring powder into an agitator vessel 122
8.13 Hybrid mixtures 123
8.14 Grinding solvent-wet plastic 123
8.15 Rotating beater dryer (2) 125
8.16 Shovelling solvent-wet powder 126
8.17 Liquids 127
8.18 Emptying a drum via a glass pipe 127
8.19 Funnel with a Mucon outlet 129
8.20 Metal valve in a glass apparatus 130
8.21 Spark discharge from an isolated metal flange 131
8.22 Rubber hose with a supporting helix 132
8.23 Isolated steel spacer in a metal pipe 134
8.24 Filling a metal drum on mobile scales 136
8.25 Slicing solvent-wet plastic 138
8.26 Application of rubber adhesive 140
8.27 Valve with a corroded PTFE coating 141
8.28 Fire during a coating process 143
8.29 Polyvinyl chloride (PVC) hose partially wetted with water 144
8.30 Glass vessel containing a mixture of toluene and water 145
8.31 Person wearing protective gloves 147
8.32 Running off ethylene oxide into a plastic bucket 148
Chapter 9. Case histories not related to static electricity 150
9.1 Pouring powder into oleum 150
9.2 Fire produced on draining off residual benzene into a plastic drum 152
9.3 Shovelling solvent-wet powder 155
9.4 Fire in an agitator vessel 156
9.5 Fire inside a filter casing at the top of a silo 157
9.6 Fire in a solvent cleaning area 159
9.7 Literature 162
Chapter 10. Shocks to people caused by static electricity 163
10.1 Metal crates containing plastic bottles 163
10.2 Cutting PE foam 164
10.3 Carbon dioxide fire extinguisher 165
10.4 Propagating brush discharge at a PP expansion pipe 167
10.5 Loading parcels into a postal van 169
10.6 Static in motor vehicles 170
Index 174