Ejection charge (commonly Black Powder), also called expelling charge, is a

pyrotechnic composition A pyrotechnic composition is a substance or mixture of substances designed to produce an effect by heat, light, sound, gas/smoke or a combination of these, as a result of non-detonative self-sustaining exothermic chemical reactions. Pyrotechnic s ...

, a type of a pyrotechnic

gas generator A gas generator is a device for generating gas. A gas generator may create gas by a chemical reaction or from a solid or liquid source, when storing a pressurized gas is undesirable or impractical. The term often refers to a device that uses a ...

designed to produce a small short-term amount of thrust to burst open a container and eject its content. In

model rocketry A model rocket are small rockets designed to reach low altitudes (e.g., for model) and be recovered by a variety of means. According to the United States National Association of Rocketry (NAR) Safety Code, model rockets are constructed of ...

, ejection charges are used to deploy a recovery system (usually

parachute A parachute is a device used to slow the motion of an object through an atmosphere by creating drag or, in a ram-air parachute, aerodynamic lift. A major application is to support people, for recreation or as a safety device for aviators, w ...

or streamer). The ejection charge is ignited through a layer of delay composition, to fire shortly after the main engine burns out. Ejection charges can be also triggered by a timer or an

altimeter An altimeter or an altitude meter is an instrument used to measure the altitude of an object above a fixed level. The measurement of altitude is called altimetry, which is related to the term bathymetry, the measurement of depth under water. The m ...

. A small amount of

black powder Gunpowder, also commonly known as black powder to distinguish it from modern smokeless powder, is the earliest known chemical explosive. It consists of a mixture of sulfur, carbon (in the form of charcoal) and potassium nitrate (saltpeter). T ...

is usually used, but

smokeless powder Finnish smokeless powderSmokeless powder is a type of propellant used in firearms and artillery that produces less smoke and less fouling when fired compared to gunpowder ("black powder"). The combustion products are mainly gaseous, compared t ...

and other compositions are possible. Ejection charge is granular black powder. Ejection charges are also used in some

flares A flare, also sometimes called a fusée, fusee, or bengala in some Latin-speaking countries, is a type of pyrotechnic that produces a bright light or intense heat without an explosion. Flares are used for distress signaling, illumination, ...

to eject the light or smoke producing components out of the flare casing. In countermeasure flares, ejection charges are used to propel the flares out of their casing, or to eject pyrophoric fluids from their containers. In cluster bombs, ejection charges are used to disperse the submunitions. Burst charges are also used to dispense leaflets from leaflet bombs. In chemical weapons, ejection charges are used to disperse the chemical agent from the bomb, submunition, grenade, or warhead.

References

Pyrotechnic compositions Model rocketry {{Pyrotechnics-stub

See also

References