Ignition by flame

These can be readily ignited by flames, sparks, static electrical discharges (often the most likely), hot surfaces, and many other sources. Table 7-31 lists dust cloud ignition temperatures ranging from 572°F to 1112° F, and can be contrasted to flammable vapor-air ignition temperatures from 428° F to 1170°F. Generally, ignition tempera-... 

The initiating explosive used must ignite with certainty from the spit of a safety fuse. It must be remembered that the intensity of the spit can be reduced if the safety fuse is not cut squarely and also that the fuse may in practice not always be fully inserted into the detonator. Lead azide by itself is not sufficiently easily ignited to give a satisfactory plain detonator and it is therefore used in admixture with lead styphnate, which is very readily ignited by flame. The proportions of such mixtures vary from 25 to 50% of lead styphnate. Mercury fulminate and diazodinitrophenol are sufficiently sensitive to flame not to require such additives. 

For ignition by flame contact (to a wall or ceiling), the flame heat flux will increase with Dp, the flame thickness of the igniter, estimated by... 

Low-Explosive (LE). An explosive which when used in its normal manner deflagrates or burns rather than detonates that is the rate of advance of the reaction zone into the unreacted material is less than the velocity of sound in the unreacted material. LE s include propellants, certain primer mixtures, BkPdr, blasting explosives (See Ref 44, p B202-L), pyrotechnic compositions and delay compositions. Whether an explosive reacts as a high explosive or a low explosive depends on the manner in which it is initiated and confined. For example, a double base propellant when initiated in the usual manner acts as a LE. However, this material can be made to detonate if it is initiated by an intense shock. Conversely, a HE like TNT, can, under certain conditions be ignited by flame and will burn without detonation (Ref 40a, p 97)... 

This mixt is more powerful than TNT or Tetranitroaniline, but is insensitive to shock or friction and burns without detonation when dropped in a red hot crucible or ignited by flame. Its ignition temp is 194-208°. It cannot be stored for longer than 24-48 hours, as bubbles, resulting from decomposition of the H2 02, are evolved and the mass hardens. Moreover its explosive power decreased after 48 hours of standing (Ref 1)... 

The first chemical explosive was invented in China around 1300 years ago and was originally used exclusively for military purposes. Black powder was not used industrially until the seventeenth century when it was adopted to blast out mines in Europe. In order to detonate black powder, it must be ignited by flame or intense heat. 

Ignition - much more easily ignited by flame or electric spark than MF, LA or DADNPh (Ref 24, p 7-12) Impact Sensitivity, BM App,... 

NGc is an explosive more powerful, but less sensitive than NG. Following are its properties, as outlined in Refs 15 65 Brisance — No information Detonation Rate 2050 7300m/sec in glass tube of 10 inches diameter at RT Explosion Temperature 257° in 5 seconds Flammability — Its explosives can be ignited by flame easier than those containing NG (Ref 15, p225)... 

Hygroscopictty at 31°C and 90% RH 0 10% Ignitibility by flame-flame of match causes burning at point of contact but does continue... 

CA 16,833(1922) (An initiating compn adapted for ignition by flame or elec spark is made of MF 80, Pb304 5-20 KC103 5-15%) 63)W.M.Dehn USP 1404687(1922) CA 16,1154(1922) (DADNPh is mixed with KCIOg or other oxidizing salt to form an initiating compn) 64)H.T.Peck,USP 1407767... 

Chromium (lll)tris(ethylenediamine) Peroxysulfate, [Cr(en)3 ] 2(S O0)3. It was reported by Beacom that this compd can be ignited by flame and exploded by exposing it to ultra-violet>radiation( 36 50A0), followed by heating to 115°. Its method of prepn was not described by Beacom and we could not find this compd listed in Beil or in the alphabetical indexes of CA s (except the listing indicated in Ref 1)... 

Properties Readily ignited by flame. Evolves about 700 calories of heat and 300 cc. of gas per gram. Various grades, specified by fineness. The fuze powder for loading time-train rings is the finest grade (passing a 140-mesh screen). 

Dimethyl Glycerol Ether l itrate, (HsC.O)CH2.CH(ONOa).eH3(OCH3) colorless liquid, mp about —15°, bp +180° sol in common organic solvents burns readily without explti when ignited by flame Diethyl Glycerol Ether Nitrate,... 

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