Introduction and detection of explosive compounds

Transcript:Introduction and detection of explosive compounds:
Introduction and detection of explosive compounds Do explosives burns or blast? What is explosive train? What are home made bombs? Are our aviations securities secure? Which is the most advanced detector? What if you as an chief security officer hear about the blast in your region? Your duties… Why proper investigation is necessary in explosion cases? Some questions for you: Ajmer Blast "bomb blast" triggered by Maoists on the rail track caused the derailment of the Howrah-Kurla express train NEWS BLOCKS ARE WE ALL SAFE??? Explosives and Explosions The Chemistry of High Energy Organic Compounds What is an Explosion? Rapid burning of a material resulting in a sudden build-up and release of heat and gas pressure. Explosive compounds Explosives are chemical compounds or mixtures which will on application of an external stimulus heat, shock, friction or ignition undergo a rapid chemical decomposition. The chemical reaction results in sudden release of large amount of energy due to liberation of gas and temperature. The pressure thus generated is thrust out equally in all directions. All explosive compounds can be considered to be composed of three components namely Fuel, Oxidizer and Sensitizer. Explosive Train An arrangement of a series of combustible and explosive elements consisting of a primer, a detonator, a delay, a relay, a lead and booster charge, one or more of which may be either combined with another element or omitted. The function of the explosive train is to accomplish the controlled augmentation of a relatively small impulse into one of sufficient energy to cause the main charge of the munition to function. A train of combustible and explosive elements arranged in order of decreasing sensitivity. The explosive train accomplishes the controlled augmentation of small impulse into one of suitable energy to actuate the main charge. Delay fuse _> shell leader _> lifting charge _> shell delay _> bursting charg e _> star prime _> star. Elements of the Explosive “Train” Low Energy Initiating Device – in the “old days” – matches, these days – electric or shot shell primer. • “Distance” element – “old days” – safety fuse, these days – electric cable, signal tube, radio frequency. • Detonator – converts the “low” energy into an explosive shock wave. Can incorporate delays. • Booster / Primer – detonator sensitive explosive to “amplify” the detonation shock wave. • Main Charge – the bulk of the explosive device. a) Explosives are classified