Prime Ignition

Zund-. ignition, lighting, priming, -apparat, m. ignition apparatus, igniter priming apparatus, primer. 

Maximum current that can be continuously applied to bridgewire circuit without igniting prime material (Note Continued applications of this current may degrade prime and dud the unit). 

Control Room. The control room location can be critical to the efficient operation of a faciHty. One prime concern is to locate it the maximum distance from the most ha2ardous units. These units are usually the units where LPG or other flammables, eg, hydrocarbons that are heavier than air, can be released and accumulate at grade level. Deadly explosions can occur if a pump seal on a light-ends system fails and the heavier-than-air hydrocarbons coUect and are ignited by a flammable source. Also, the sulfur recovery unit area should be kept at a healthy distance away as an upset can cause deadly fumes to accumulate. 

A diesel-electric locomotive uses as its prime mover a large, self-igniting, internal combustion engine of the type invented by RudolfDiesel and first successfully demonstrated in 1897. Thermal efficiency of these engines exceeded 30 percent, compared... 

Pb mononitro resorcinate, and NC priming material are followed by a chlorate, charcoal, lacquer mixt for flame and fire transfer, and protective coatings of clear lacquer form a bulb resembling a book-match tip. Ignition is achieved by a current of 500mA for a minimum of 50msec. This is one example of a series of electric matches which are manufd to various current input requirements with different chemical compos... 

Thallium. Ignition point 208° (Ref 12) has greatest expl effect in lead plate test when primed with MF (Ref 7). It is a useful detonator at d 1.1—1.2g/cc, but usefullness decreases at higher d (Ref 7)... 

Percussion. The act of striking one body against another with a sharp blow. As some expls, such as MF or LSt are very sensitive to such a blow (shock or impact), they may be expld (or ignited) by such action. In this case, the term percussion can be applied to initiation or priming by such action, as weil as to the expln (or deflagration or ignition) caused by percussion... 

A review of the vast amt of work performed in the field of percussion primers reveals what is essentially an empirical approach to the development of both primer designs and priming mixts. It is recognized that a percussion primer must perform two vital functions (1) it must fire , ignite , or otherwise function when provided with the proper mechanical stimulus — a firing pin (with optimum contour to its striking end) and (2) it must perform its other function by which the flame , fire , or output will ignite the proplnt properly so as to provide the projectile with the specified velocity and within... 

Bentzinger, von R. et al Praxis Naturwiss. Chem., 1987, 36, 38 A priming mixture of magnesium powder and barium peroxide to ignite thermite mixture was to be prepared, but as no barium peroxide was available, sodium peroxide was used instead. Some time after preparation, the mixture ignited spontaneously, because sodium peroxide, unlike barium peroxide, is very hygroscopic and forms hot cone, hydrogen peroxide from contact with atmospheric moisture. See Carbon dioxide, etc., above... 

As the important effect of temperature on NO formation is discussed in the following sections, it is useful to remember that flame structure can play a most significant role in determining the overall NOx emitted. For premixed systems like those obtained on Bunsen and flat flame burners and almost obtained in carbureted spark-ignition engines, the temperature, and hence the mixture ratio, is the prime parameter in determining the quantities of NOx formed. Ideally, as in equilibrium systems, the NO formation should peak at the stoichiometric value and decline on both the fuel-rich and fuel-lean sides, just as the temperature does. Actually, because of kinetic (nonequilibrium) effects, the peak is found somewhat on the lean (oxygen-rich) side of stoichiometric. 

Both 2,4-dinitrosoresorcinol (23) and 2,4-dinitroresorcinol (24) are important in the explosives industry. The lead salt of 2,4-dinitrosoresorcinol has a low ignition temperature and finds use in priming compositions and in electrical igniters. The lead salt of 2,4-dinitroresorcinol is a weak initiator but is found to exhibit high sensitivity to friction and stab action without being highly sensitive to impact, and as such, this compound has found use in primers. 

For about 500 years black powder enjoyed dominance as a propellant, explosive and igniter, and as the major firework ingredient its use remains unsurpassed. The prime reason for the longevity of black powder is its quickness , even at relatively low pressures, and this is brought about by manufacturing techniques (as described earlier) and the chemical reactivity of the constituents. 

However, at the present time it appears that there is not a significant problem with the employment of sulfur gunpowder for the priming of chlorate compositions, and so the main use of sulfurless powders again rests with the military, particularly where igniter and priming compositions are in contact with magnesium. 

PRIME A layer of readily ignited explosive composition that is applied to the surface of the main composition in order to facilitate ignition. 

Primer-Igniter Mine Fuze. An item consisting of priming and initiating devices designed to initiate an antipersonnel mine (Ref 40a, p 112)... 

Priming Composition. A physical mixture of materials that is very sensitive to impact or percussion and, when so exploded, undergoes very rapid autocombustion. The products of such an explosion are hot gases and incandescent solid particles. Priming compositions are used for the ignition of primary explosives, BkPdr, igniter charges and propellants in small arms ammunition (Ref 40a, p 112) (See also in Section 3, Part D and Section 4,... 

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