Sea Flares

Few industrial uses have so far been found for phosphides. Ferrophosphorus is produced on a large scale as a byproduct of P4 manufacture, and its uses have been noted (p. 480). Phosphorus is also much used as an alloying element in iron and steel, and for improving the workability of Cu. Group 3 monophosphides are valuable semiconductors (p. 255) and Ca3P2 is an important ingredient in some navy sea-flares since its reaction with water releases spontaneously flammable... 

The first successful phosphorus-containing striking matches were invented by Sauria in 1831, and the use of the element in match compositions was introduced in England and France abont 1838. Phosphorus sesquisulphide, discovered by Letnoine in 1864, eventually replaced the toxic white form of the element. Safety matches incorporating red phosphorus were introduced by Sevene and Cahen in 1898. Self-igniting sea flares incorporating calcium phosphide were patented by Holmes and Player in 1876. 

GB patents for self-ignihng sea flares utilising Ca3P2... 

Pure calcium monophosphide, CaP, is best prepared by passing phosphine into calcium dispersed in liquid ammonia. The addition compound which is formed can then be heated at 150°C to give the monophosphide, which above 600°C converts into a lower phosphide with loss of phosphorus (8.16). The lower phosphide liberates phosphine on contact with water (8.17). It is made commercially by heating quicklime in phosphorus vapour, and, together with Mg3P2, it finds application in sea flares. Sea flares are spontaneously inflammable due to the presence of small quantities of diphosphine which arise from the presence of impurity CaP (8.15). 

The first application of a phosphorus compound was probably in sea flares, which incorporated calcium phosphides. This took place around 1876 and was originally developed for marine protection in general. 

Miscellaneous applications which include, for example, sea flares (Section 12.16), rat poisons, catalysts, grain fumigants and so on. 

Most phosphides are industrially worthless however, a few are valued for some special property. Aluminum phosphide finds application as a semiconductor, and CasP2 is employed in sea flares to produce flammable phosphine gas (PH3) ... 

Product quality is not limited to oil and gas quality certain effluent streams will also have to meet a legal specification. For example, in disposal of oil in water, the legislation in many offshore areas demands less than 40 ppm (parts per million) of oil in water for disposal into the sea. In the UK, oil production platforms are allowed to flare gas up to a legal limit. 

Although the corrosivity may not be high provided the condensed moisture remains uncontaminated, this rarely happens in practice, and in marine environments sea salts are naturally present not only from direct spray but also as wind-borne particles. Moreover, many marine environments are also contaminated by industrial pollution owing to the proximity of factories, port installations, refineries, power stations and densely populated areas, and in the case of ships or offshore installation superstructures by the discharge from funnels, exhausts or flares. In these circumstances any moisture will also contain S, C and N compounds. In addition, solid pollutants such as soot and dust are likely to be deposited and these can cause increased attack either directly because of their corrosive nature, or by forming a layer on the surface of the metal which can absorb and retain moisture. The hygroscopic nature of the various dissolved salts and solid pollutants can also prolong the time that the surface remains moist. 

Flares. A flare compn is described in Refs 15 16 contg powd Mg, Na perchlorate, and a binder which can be cast and cured, and which has a luminous intensity of 50,500 candle-secs/g Incendiaries. A mixt of 1 OOg of Na perchlorate and 58.7g of powd Al has a Qr of 2751cal/g and can be used as a filler for incendiary bombs (Ref 6). A proc is described in Ref 14 for coating Na perchlorate with Al, and the use of the coated material in incendiaries Photo flash Compositions. Mixts of 80% Ca metal and 20% Na perchlorate and 80% Ca, 10% Na perchlorate, and 10% Na nitrate have been examined as expl photoflash compns for both sea level and high altitude use (Ref 13) Refs 1) Gmelin, System No 21 (1928), 408 Supp Part 1 (1964), 180 2) H.H. Willard ... 

This method was applied earlier to produce floating signal flares at sea. Floating cans of calcium phosphide were punctuated to admit sea water to generate phosphine, which ignited spontaneously to emit flares. The flares could not be extinguished by wind or water. 

Flare, Float and Flare, Surface. A float flare is a pyrotechnic signal launched from an air craft to mark a location at sea. It floats on die surface and emits smoke and flare for up to one hour. A surface flare is a pyrotechnic item for use in surface position, ground or water, designed to produce a single source of intense light for purposes such as illumination of airport runway and warning of infiltrating enemy troops... 

Incidentally, the small amount of iron introduced into sea water by such corrosion, or by intentional chemical addition, is considered beneficial by some authorities for promoting protective films on copper-base alloys. Reduced attack can also be accomplished by flaring the tube ends to facilitate streamline flow. It is essential that the cross-over area in the head or channel be larger than the cross-sectional area of the tubes to reduce turbulence. Munro (6) recommends 125% for the cross-over area in water boxes for sea-water service. Also from the standpoint of turbulence, side entry is preferred to axial entry at the front end of the condenser. 

Between sea level and the upper limit of the earth s atmosphere there is about 1000 g cm of air mass. The earth s atmosphere provides an effective shield against cosmic radiation the dose rate doubles for every 1500-2000 meters increase in altitude. Dose rates at the edge of the atmosphere at high altitudes are around 1000 times higher solar flares can increase these levels by orders of magnitude. 

These are used as illuminant and they hang from a parachute. Increasing population density and urbanization mean that parachute flares are going to be gradually phased out for safety. They can still however be used at sea, on lakes, in the desert or in a district where there is no danger of fire. 

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