Shells, aerial

Consumer Fireworks. An assortment of small fireworks devices are permitted for use by private citizens in many areas in the United States and elsewhere throughout the wodd. These devices consist of items such as wire sparklers, fountains, Roman candles, sky rockets, mines, and small aerial shells. 

Copper (Cu) is a bright brown-colored metal. When Cu powder or wire is heated in a high-temperature flame, its characteristic blue-colored emission is observed. Thus, Cu particles are commonly used as a component of aerial shells of fireworks. 

J.E. Mercer, Thermodynamics of Black Powder and Aerodynamics of Propelled Aerial Shells , Journal of Pyrotechnics, Issue 16, pp. 37-52, 2003. 

Picric acid added in small quantities to colors deepens them and increases their brilliancy without making them burn much faster. Stars containing picric acid ought not to be used in aerial shells, for they are likely to detonate either from the shock of setback or later from being ignited in a confined space. Mixtures which contain picric acid along with potassium chlorate or salts of heavy metals are liable to detonate from shock. 

Lampblack stars burn with a rather dull soft light. Discharged in large number from a rocket or aerial shell, they produce the beautiful willow-tree effect. They are made, according to Allen F. Clark, by incorporating 3 pounds of lampblack, 4 pounds of meal powder, and 2 pound of finely powdered antimony sulfide with 2 ounces of shellac dissolved in alcohol. 

Aerial fireworks usually are of two types, aerial shells fired from tubes and the traditional skyrocket. Rockets are made of cardboard tubes filled with a mixture of fuel and oxidizer in proportions that allow continuous burning rather than explosion. Expulsion of gases from the tube propels it skyward. Rockets often contain explosive charges to explode after the propellant charge burns out the composition of the explosive charge determines the colors produced. 

Uses Lead-TNP is used in initiating compositions in place of lead styphnate or diazodinitrophenol for blasting caps and detonators, in priming compositions in place of mercury fulminate or in combination with sulfur nitride, triazoles, or tetrazoles, for use in bullet primers and the like. Lead-TNP can also be used in fireworks to detonate black powder for increased bursting effects in aerial shells. Lead-TNP should be handled with care. Never store dry, and keep submerged in a water free solvent... 

A typical aerial shell used in fireworks displays. Time-delayed fuses cause a shell to explode in stages. In this case a red star-burst occurs first followed by a blue starbursb and finally a flash and loud report. Reprinted with permission from Chemical Engineering News, Vol. 59, Issue 26, June 29,1981, p. 25. Copyright 1981 American Chemical Society. 

A typical aerial shell is shown above. The shell is launched from a mortar (a steel cylinder), using... 

A typical aerial shell is shown in the diagram. The shell is launched from a mortar (a steel cylinder) using black powder as the propellant. Time-delayed fuses are used to fire the shell in stages. A list of chemicals commonly used in fireworks is given in the table. 

Smokeless powders are widely used today as the propellants for small arms ammunition as well as for artillery projectiles. Black powder use fell dramatically as the twentieth century began, with the introduction of the smokeless propellants, but it remains the primary propellant used by the fireworks industry for sky rockets and for aerial shells fired from mortars, and is still used for a variety of military applications as well. 

Fig. 14.1 Typical structure of an aerial shell for fireworks display. The compartments of the rocket usually produce different colored fireworks and patterns ...

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