Detonation development distance

Aniaufstrecke = detonation development distance 90 Antenne - bus wire 47 antigrisouteux - permitted explosives 248... 

The detonation development distance, especially that of less sensitive explosives, is strongly affected by the consistency, density and the cross-section of the charge. 

Primary explosives, when set off by a flame, must detonate immediately, and their detonation development distance must be as short as possible. 

Silver fulminate is much more sensitive than mercury fulminate. Since its detonation development distance is very short, its initiation effect is superior to that of mercury fulminate, but the compound is too sensitive to be used commercially. 

Estimation of Minimum Distances for Spontaneous Detonation Development... 

Based on the calculation results from [28], the empirical formula = la for assessing minimum distances (mixture dimensions) L, which allow spontaneous detonation development are proposed in [41]. 

A great deal of experimental work has also been done to identify and quantify the ha2ards of explosive operations (30—40). The vulnerabiUty of stmctures and people to shock waves and fragment impact has been well estabUshed. This effort has also led to the design of protective stmctures superior to the conventional barricades which permit considerable reduction ia allowable safety distances. In addition, a variety of techniques have been developed to mitigate catastrophic detonations of explosives exposed to fire. 

Flame plating (D-gun) employs oxygen and fuel gas. In this method, developed by the Union Carbide Corporation, the gas mixture is detonated by an electric spark at four detonations per second. The powders, mixed with the gas, are fed under control into a chamber from which they are ejected when detonation occurs. The molten, 14—16-pm particles are sprayed at a velocity of 732 m/s at distances of 5.1—10.2 cm from the surface. The substrate is moved past the stationary gun. 

The Canadian Standards Association Standard Z343 (CSA 1998) presents test methods for in-line and firebox flame arresters. In this standard in-line flame arresters are limited to only detonation types and firebox flame arresters are defined as flame arresters installed in an enclosnre, or system of enclosnres, where the mn-np distance is less than 1.5 meters and open to the atmosphere. Firebox flame arresters are commonly nsed on eqnip-ment designed to heat flnids in prodnction operations snch as indirect heaters, emnlsion treaters, and glycol dehydrators. The development history of this standard is presented in Section 2.3.2. 

Experimental data and theoretical considerations suggest that water pressures developed in LNG-water RPTs are significantly less than critical pressure of the LNG. Measured values have not exceeded 10-20 bar. Average overpressures in the air show a rapid decay with distance and are approximately equivalent to values expected from the detonation of a few tenths of a kilogram of TNT (see Section III,K). 

The distance at which transition takes place is called "carry-over distance . Its method of determination by means of the rapid photographic camera developed in 1944 by RRL (Road Research.Lab) is described in Ref and the results of tests are shown in Figs 7 to 13 of paper. See previous item Ref W.M Evans, "Some Characteristics of Detonation , PrRoySoc 204A, pp 15-17(1950) (Transition of detonation)... 

In any horizontal section (such as the one indicated by the broken line in the sketch), let be the distance from the detonation products/ vacuum boundary to the metal plate. For any such horizontal section, the equations developed in Appendix B will hold if x is set equal to zero at the detonation products-vacuum boundary. 

---