Photographic observation of channel effect in the detonation of emulsion explosive

Book · Sat Dec 31 04:00:00 EST 1994

OSTI ID:398339

Sumiya, Fumihiko; Kawami, Kazuyoshi; Kurokawa, Koichi ^[1]; Wada, Yuji; Ogata, Yuji; Katsuyama, Kunihisa ^[2]

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1. NOF Corp., Aichi (Japan). Explosive and Blasting Research Group
2. National Inst. for Resources and Environment, Tsukuba, Ibaraki (Japan)

When explosives are detonated in the borehole where there is an air gap between the explosive charge and the borehole of inner wall, the shock wave in an air gap travelling ahead of the detonation front will be generated. This shock wave is called the precursor air shock wave (PAS). The explosive is precompressed by the PAS, and as a result of that a detonation failure occurs on occasion. This phenomenon is well known as channel effect. The purpose of the investigation is to consider methods of the prevention of the detonation failures. As a fundamental study on the mechanism of channel effect, the relation between the detonation wave and the PAS were observed by high speed photography. In these experiments, the authors used some typical water-in-oil emulsion explosives. The explosives were with the same matrix but different kinds of resin micro-balloons (RMBs) as a sensitizer. By using different kinds of RMBs, that the various detonation velocities of the explosives which range from 3,000--4,900m/s were obtained. Sample explosives were examined under various conditions which were in different decoupling coefficients. The experiments showed that the higher the detonation velocity of explosive was, the higher the PAS velocity became. The explosives were exposed under drastic conditions like high temperature and pressure. When the decoupling coefficient was the range of 1.2--2.7, the phenomenon of the detonation failure was observed. The emulsion structure was destroyed after the detonation failure. The precompression speed of explosive was the range of 120--0170m/s in these experiments.

• OSTI ID: 398339
• Report Number(s): CONF-9401127--
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
CHEMICAL EXPLOSIVES
COMPARATIVE EVALUATIONS
DETONATORS
EXPERIMENTAL DATA
EXPLOSIVE FRACTURING
FAILURES
MITIGATION
SHOCK WAVES
ULTRAHIGH-SPEED PHOTOGRAPHY