Smoke-generating pyrotechnics

Smoke-Generating Devices. Smoke generators are used by the military for daytime obscuration and signaling. For field use where portable stable systems ate requited, pyrotechnic devices are often employed. The primary composition since the 1940s has been HC smoke, which generates a cloud of zinc chloride, ZnCl, smoke by a series of reactions between hexachloroethane, C2Clg(HC), zinc oxide, and aluminum (3) (eq. 4—6). The zinc regenerated in... 

The following are pyrotechnic methods for smoke generation as opposed to mechanical methods such as atomization of fog oil, of Ti tetrachloride (FM smoke) or of S trioxide. This discussion is drawn from Ref 134, which should also be consulted for earlier references ... 

Smoke Generator (Hatsuenku). See under Smoke Pyrotechnics... 

Table 8.7 Examples of pyrotechnic compositions used as smoke generators...

Pyrotechnics include illuminating flares, signaling flares, colored and white smoke generators, tracers, incendiary delays, fuses, and photo-flash compounds. Pyrotechnics usually are composed of an inorganic oxidizer and metal powder in a binder. Illuminating flares contain sodium nitrate, magnesium, and a binder. Signaling flares contain barium, strontium, or other metal nitrates [1]. 

CN is a white solid with low vapor pressure that can be dispensed as a fine powder or as a jet or stream of solution from small or large spray tanks, as well as aerosols or smokes by pyrotechnic generation. Its solubility in water is limited, but it is soluble in organic and chlorinated organics. Exposure of eyes, nose, mouth, skin, and respiratory tract produces irritation and pain. If swallowed, CN may produce vomiting. 

RCAs are solids with low vapor pressures. They can be dispersed as fine powders foams, as coherent jets or streams of solutions from small or large spray cans, large spray tanks, or larger weapons and as aerosols or smokes by pyrotechnic generation (Table 2). 

Hartley, F.R., Murray, S.G. and Williams, M.R. (1984) Smoke generators. IV the ignition of loose powder mixtures of pyrotechnic white smoke compositions containing hex-achloroethane and silumin in sealed tubes. Propellants Explos. Pyrotech., 9,... 

Other uses of hexachloroethane are as moth repellent, plasticizer for cellulose esters, anthelmintic in veterinary medicine, mbber accelerator, and as a component in fungicidal and insecticidal formulations. Hexachloroethane reacts with silumin (an aluminum /siUcon alloy) at 483 K to generate an intense white smoke, which is useful in certain pyrotechnics (154). 

The pyrotechnic generation of smoke is almost exclusively a military device for screening and signaling. While first encountered on a significant scale in WWI, its importance was not realized until early in WW1I when the bulk of the presently known data were collected. In the last 30 years studies of smoke have continued at a reduced rate... 

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