On the transition to explosion of the burning of explosives

✍ Scribed by K.K. Andreev

• Publisher: Elsevier Science
• Year: 1963
• Tongue: English
• Weight: 956 KB
• Volume: 7
• Category: Article
• ISSN: 0010-2180
• DOI: 10.1016/0010-2180(63)90176-7

✦ Synopsis

The differences between burning of explosives and detonation are reviewed in the light of a number of research reports, and factors affecting the transition are noted. The acceleration of burning of granular explosives is discussed, with notes on effect of particle size and charge density, followed by observations on secondary solid explosives and the transition of the burning of liquid explosives into explosion. The dual effect of pressure upon stability of burning is jinally considered briefly.

The Basic Differences between Detonation and Burning

ONE of the principal ways in which the detonation of explosives differs from their burning is in an incomparably higher rate of propagation. Inasmuch as the maximum temperatures reached during detonation and burning do not significantly differ, the cause of the difference between burning and detonation might be considered to be the pressure at which the reaction takes place. It is known that in detonations the chemical reaction is initiated during the passing of a shock wave and occurs at pressures of the order of 10s atm, whereas during burning it proceeds usually at much lower pressures.

However, this difference is not sufficient. Indeed, the rate of burning of explosives, for instance PETN at 100 atm, is about 1 cm set-l and it increases in proportion to the pressure, as was established1 in the pressure interval up to 1000 atm for this explosive and up to 10 000 atm for some others.

Assuming that proportional growth maintains for still higher pressures, at 100000 atm the burning rate would still be only lo3 cm see-I. It might be somewhat higher as a result of a possible rise in the temperature of the explosive due to compression by, the shock wave. However, the burning rate of explosives2, and also the critical detonation diameter, do not depend very much on the