Electrostatic sparks

For local, short-duration heat sources, such as electrostatic sparks, the reported ignition energies for different pressures are on the orders of magnitude given in Table 2 (48—50). 

The minimum ignition energy of Hquid acetylene under its vapor, when subjected to electrostatic sparks, has been found to depend on the temperature as indicated in Table 3 (86). Ignition appears to start in gas bubbles within the Hquid. 

Electrostatic spark discharge and ignition during charging of solids resulting in possibility of fire/explo-sion. Potential for explosion to start a thermal decomposition of reaction mass. 

Electrostatics enters into the problem of secondary explosions in several ways. First, an electrostatic spark may be the ignition source of the primary explosion. Second, an electrostatic spark can serve to ignite a dust cloud if particulate spews out at high velocity as a result of a sudden piping or vessel containment failure. Similar containment failures have occurred with insulating liquids and can not be ruled out for powders. For example,... 

Although thermal decomposition (and runaway) is often identified with the inherent reactivities of the chemicals involved, it must be emphasized that hazards can arise from induced reactions as discussed in Chapter 2. These induced reactions may be initiated by heat, contamination, or mechanical means (e.g., shock, friction, electrostatic spark). 

Ad 181) G.W.C. Taylor et al, BritP 1086861(1967) CA 68, 1422(1968)(Finely divided B is incorporated into primary expls to reduce their sensitivity to accidental ignition by electrostatic sparks. In some cases, this incorporation also increases the power percussion sensitivity of the expls) Ad 182) D.M. Welsh, CanP 770392(1967)... 

This represents the ease with which an explosive can be set off by an electrostatic spark... 

Electrostatic spark 0.001 8kv sensitiviry, fires above, jrfd... 

HNS has a uniquely small critical diam ( 0.020 inch), i s practically insensitive to electrostatic spark, is less sensitive to impact than Tetryl, is radiation resistant, and is the only commercially available expl meeting the expl sensitivity requirements of the Fuze Design Safety Criteria of all three services (Ref 8) Uses HNS is used as a heat-resistant booster expl. It is sufficiently insensitive to heat, impact, and electrostatic spark to be used in mild detonating fuse (MDF) end couplers St end boosters. It may find application in leads and in plastic-bonded HE s... 

The last section of Ref 35, entitled " A Proposed Research Program for Electrostatic Sensitivity Testing of Primary Explosives is intended to lead to improved procedures and a better understanding of electrostatic spark initiation... 

P.W.J Moore, J.F.Sumner R.M.H. Wyatt, The Electrostatic Spark Sensitiveness of Initiators Part I—Introducr tian and Study of Spark Characteristics , ERDE(Explosives Research. and Development Establishment) Report4/T/56, Waltham Abbey, Essex, England (Jan 1956)... 

The Electrostatic Spark Sensitivity of Bulk Explosives and Metal/Oxidant Mixtures NA.VORD Rept 6632 (June 1959)... 

The research into energetic molecules which produce a large amount of gas per unit mass, led to molecular structures which have a high hydrogen to carbon ratio. Examples of these structures are hydrazinium nitroformate (HNF) and ammonium dinitramide (ADN). The majority of the development of HNF has been carried out in The Netherlands whereas the development of ADN has taken place in Russia, USA and Sweden. ADN is a dense non chlorine containing powerful oxidiser and is an interesting candidate for replacing ammonium perchlorate as an oxidiser for composite propellants. ADN is less sensitive to impact than RDX and HMX, but more sensitive to friction and electrostatic spark. 

Butterworth, G.J., The detection and characterisation of electrostatic sparks by radio methods, Inst. Phys. Conf. Ser. No. 48, pp. 97-105, London, 1979. 

Particle size, microns Bulk density, g/cc Differential thermal analysis, onset of exotherm Electrostatic spark sensitivity, fires above, d Friction sensitivity,... 

Uses HNS is used as a heat-resistant booster expl. It is sufficiently insensitive to heat, impact, and electrostatic spark to be used in mild detonating fuse (MDF) end couplers S end boosters. It may find application in leads and in plastic-bonded HE s... 

R.W.Van Dolah. Electrostatic Spark Test on 9 Samples of Explosives , US BurMines Rept 3426 (Dec 1954) Project 2301- 185 15) R.E. Braid, R.C. Langille... 

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