Electric detonator capsules or, in other words, electric detonators act by converting electrical energy into heat. In the design of electric detonators, one way or another, an electric igniter and a radiation detonator capsule are combined.
Electric detonator caps, bridge and spark electric detonators, principle of operation and device.
Electric detonators are designed to create an initial detonation pulse and initiate an explosive chemical reaction in the bulk of the explosive charge. Unlike a conventional detonator capsule, which is detonated with a flame or detonating cord, as well as a detonating tube, an electric detonator is electrically detonated.
In addition to military affairs, an electric detonator can be used on explosive charges on the earth’s surface, in mines and mines, which are not hazardous by the presence of gas and dust. According to the principle of action, electric caps-detonators (electric detonators) bridge and spark are distinguished, and according to the purpose, electric detonators distinguish between subversive and ammunition (tube).
Subversive Electric Detonators.
Subversive electric detonator is a combined in one design beam detonator capsule No. 8 and a bridge electric igniter. An electric detonator is designated according to the principle: ED No. 8-A, ED No. 8-M. The letters “ED” mean “electric detonator”, No. 8 type of radiation capsule detonator, letters after the number of shell material (A aluminum, M copper). In military affairs, the electric detonator EDP, EDP-R and others are also used..
Electric detonator EDP.
Ammunition detonators are subject to particularly stringent requirements in terms of instantaneous action, uniformity of action and compact design. This is achieved by maximizing the electric igniter with the detonator capsule..
Bridge and spark detonator.
The charge of the electric igniter is the igniter layer (TNRS) of the primary charge of the detonator capsule or directly the primary charge. Moreover, the primary charge in the second case is made from a mixture of 20-40% THRS and 80-60% lead azide. Due to this, the sensitivity of the primary charge to heating from the bridge increases, providing high reliability and reliability of the capsule.
High instantaneous action is characterized by a spark electric detonator, in which the spark gap is in the layer of the primary charge-beam detonator capsule. The spark gap is approximately 0.2 mm. The operation of the capsule occurs when high voltage (2000-10 000 V) is applied to the central contact and the housing (shell). The response time can range from fractions of a microsecond to 5.6 μs.
The disadvantage of spark detonators is the dependence of their action on the magnitude of the spark charge. With slight deviations in one direction or another, failures in the operation of this type of electric detonators are possible.
Based on the book Explosives and gunpowder.
A.N. Kalyazhenkov, D.P. Malgin.