Electrostatic Hazards

Contents......Page 5
Foreword......Page 9
Acknowledgements......Page 11
1.2 Conditions for ignition......Page 12
Solid fuels......Page 14
1.2.2 Oxygen......Page 15
1.2.3 Ignition sources......Page 16
1.2.4 Summary......Page 17
1.3 Minimum ignition energy......Page 18
Gases and vapours......Page 19
1.3.2 Dependence of MIE on oxygen concentration......Page 21
1.3.3 Overview......Page 22
1.4 Literature......Page 24
2. Origin of static electricity......Page 25
2.1 Double layer charge......Page 26
2.1.1 Charge separation......Page 28
2.2.1 Charging of flowing liquids......Page 30
2.3.1 Decrease the interfacial area of contact......Page 31
2.3.2 Use of the triboelectric series......Page 32
2.3.3 Reduce the surface resistivity......Page 33
2.4 Electrostatic induction......Page 35
2.5.3 Volume charge density......Page 39
2.5.6 Field strength......Page 40
2.5.9 Volume resistivity......Page 41
2.5.12 Capacitance......Page 42
2.6 Static charges on the clothing and the body......Page 43
Incendiary discharges......Page 44
2.6.2 Static discharges from clothing fabrics......Page 47
2.7 Literature......Page 49
3.2 Mechanisms of gas discharges......Page 50
3.3 Types of gas discharge......Page 51
3.3.1 Corona discharges......Page 52
Corona neutralizers for static elimination......Page 54
3.3.2 Brush discharges......Page 56
3.3.3 Super brush discharges......Page 58
3.3.4 Cone or bulking discharges......Page 60
Propagating brush discharges on shielded systems......Page 61
3.3.6 Spark discharges......Page 63
3.4.1 Assessment of ignition energy......Page 64
3.4.2 Table of incendivity......Page 65
3.5 Traces left by gas discharges......Page 66
3.6 Literature......Page 67
4. Principles of safety......Page 69
5.1 Ignition in a heated tank containing diphenyl......Page 73
5.2 Pouring flaked product into an agitator vessel......Page 75
5.3 Filling pipe blocked with sulphur leading to the ignition of methanol......Page 77
5.4 PE liner slipping out of a paper bag......Page 78
5.5 Ignition caused by an antistatic PE bag......Page 79
5.6 Impregnation of a glass fibre fabric......Page 80
5.7 Shaking fine dust out of a PE bag......Page 82
5.8 Ion exchanger resin in toluene......Page 83
5.9 Pumping polluted toluene......Page 84
6.1 Plastic foam released from an autoclave......Page 87
6.2 Dust explosion in a silo......Page 88
7.1 Plastic tube used in the pneumatic conveying of powder......Page 90
7.2 Plastic pipe used in the pneumatic conveying of powder......Page 92
7.3 Plastic injector in a jet mill......Page 93
7.4 PE liner in a metal drum......Page 95
7.5 PE liner in a paper drum......Page 97
7.6 Polymethylmethacrylate (PMMA) window pane in the silo of a granulating plant......Page 98
7.7 PP coated expansion pipe......Page 100
7.8 Plastic tank inside a metal mould......Page 101
7.9 Literature......Page 102
8.2 Rotating beater dryer (1)......Page 103
8.3 Explosion of a resin powder in a metal drum......Page 105
8.4 Dust removal from tablets......Page 107
8.5 Filter bag with a supporting framework......Page 108
8.6 Filter fabric containing interwoven steel fibres......Page 110
8.7 Explosion when emptying a metal drum......Page 112
8.8 Filter fabric made partially conducting by a flame- proofing agent......Page 114
8.9 Emptying a tumble dryer......Page 116
8.10 Cyclone separator set up on a drum......Page 118
8.11 Fire caused by an antistatic PE bag......Page 119
8.12 Pouring powder into an agitator vessel......Page 120
8.14 Grinding solvent-wet plastic......Page 121
8.15 Rotating beater dryer (2)......Page 123
8.16 Shovelling solvent-wet powder......Page 124
8.18 Emptying a drum via a glass pipe......Page 125
8.19 Funnel with a Mucon outlet......Page 127
8.20 Metal valve in a glass apparatus......Page 128
8.21 Spark discharge from an isolated metal flange......Page 129
8.22 Rubber hose with a supporting helix......Page 130
8.23 Isolated steel spacer in a metal pipe......Page 132
8.24 Filling a metal drum on mobile scales......Page 134
8.25 Slicing solvent-wet plastic......Page 136
8.26 Application of rubber adhesive......Page 138
8.27 Valve with a corroded PTFE coating......Page 139
8.28 Fire during a coating process......Page 141
8.29 Polyvinyl chloride (PVC) hose partially wetted with water......Page 142
8.30 Glass vessel containing a mixture of toluene and water......Page 143
8.31 Person wearing protective gloves......Page 145
8.32 Running off ethylene oxide into a plastic bucket......Page 146
9.1 Pouring powder into oleum......Page 148
9.2 Fire produced on draining off residual benzene into a plastic drum......Page 150
9.3 Shovelling solvent-wet powder......Page 153
9.4 Fire in an agitator vessel......Page 154
9.5 Fire inside a filter casing at the top of a silo......Page 155
9.6 Fire in a solvent cleaning area......Page 157
9.7 Literature......Page 160
10.1 Metal crates containing plastic bottles......Page 161
10.2 Cutting PE foam......Page 162
10.3 Carbon dioxide fire extinguisher......Page 163
10.4 Propagating brush discharge at a PP expansion pipe......Page 165
10.5 Loading parcels into a postal van......Page 167
10.6 Static in motor vehicles......Page 168
Index......Page 171