Fire accelerants

If the release results in limited evaporation of the flammable liquid, a pool will form on the ground, and if ignited, will cause the material to bum above the liquid surface of the pool, resulting in a pool fire. Heat from the fire accelerates evaporation from the pool, sustaining the fire. Damage from pool fires is usually localized and results from radiant heat and direct flame contact. 

Distinct ion chromatograms are observed from debris derived from fire accelerant and those resulting from the pyrolysis of various polymers. Selected ions representing the following categories of... 

The most obvious sign of the presence of some form of fire accelerant is the smell. Petrol and other flammable liquids tend to soak, unbumt, into carpets and other furnishings. Flammable substances will often continue to vaporise after the fire has been extinguished and therefore can be detected by smell or specialist sensing equipment. Another classic sign that a fire has involved flammable liquids is the presence of circular or running burn patterns on floors or walls surfaces. 

Gun Propellents. Although the stresses on individual gun propellant grains are less severe because of the small size, these propellants must withstand much higher weapon pressures and accelerations. Formulation options are usually more limited for gun propellants than for rocket propellants because the products of combustion must not foul or corrode a gun, should have a low flame temperature, and should exhibit minimum flash and smoke characteristics. Gun propellants are examined microscopically for porosity, are tested for mechanical characteristics, and fired in closed bombs to determine the burning characteristics. 

On firings the gases from the propellant accelerate the piston that compresses the light gas in front of it. At a preestablished pressure, the projectile is propelled down the launch tube accelerated by the low molecular weight gas which follows the projectile to the mouth of the tube. The target material is placed in front of the launch tube, and appropriate instmmentation used to estabUsh the characteristics of the interface reaction between projectile and target (117-120). 

This hydrolysis reaction is accelerated by acids or heat and, in some instances, by catalysts. Because the flammable gas hydrogen is formed, a potential fire hazard may result unless adequate ventilation is provided. Ingestion of hydrides must be avoided because hydrolysis to form hydrogen could result in gas embolism. 

Reiaforced plastics may also iaclude fillers (qv), which are iaexpeasive materials such as calcium carboaate used to displace resia and reduce cost curing agents (catalysts), promoters, inhibitors, and accelerators, which affect thermosetting resia cure colorants release agents (qv) to faciUtate removal from the mold and other additives which can impart a wide variety of properties to the finished part, such as fire resistance, electrical conductivity, static dissipation, and ultraviolet resistance. 

Another method iavolves an electric-arc vaporizer which is >2000° C before burning (25,32). One of the features of the process is a rapid quench of the hot gas flow to yield very fine oxide particles (<0.15 nm). This product is quite reactive and imparts accelerated cure rates to mbber. Internally fired rotary kilns are used extensively ia Canada and Europe and, to a limited extent, ia the United States (24). The burning occurs ia the kiln and the heat is sufficient to melt and vaporize the ziac. Because of the lower temperatures, the particles are coarser than those produced ia the other processes. In a fourth process, ziac metal which is purified ia a vertical refining column is burned. In essence, the purification is a distillation and impure ziac can be used to make extremely pure oxide. Also, a wide range of particle sizes is possible (33). 

Hemihydrate. The abiUty of plaster of Paris to readily revert to the dihydrate form and harden when mixed with water is the basis for its many uses. Of equal significance is the abiUty to control the time of rehydration in the range of two minutes to over eight hours through additions of retarders, accelerators, and/or stabilizers. Other favorable properties include its fire resistance, excellent thermal and hydrometric dimensional stabiUty, good compressive strength, and neutral pH. 

Fire Hazards - Flash Point (deg. F) 113 OC Flammable Limits in Air (%) Not pertinent Fire Extinguishing Agents Water, dry chemical, carbon dioxide Fire Extinguishing Agents Not To Be Used Not pertinent Special Hazards of Combustion Products Not pertinent Behavior in Fire May explode. Bums with accelerating intensity Ignition Temperature (deg. F) Explodes Electrical Hazard Data... 

High-temperature corrosion is induced by accelerated reaction rates inherent in any temperature reaction. One phenomenon that occurs frequently in heavy oil-firing boilers is layers of different types of corrosion on one metal surface. 

Immediately after this blast, a fire originated at the west end of B Module and erupted into a fireball along the west face. The fire spread quickly to neighboring portions of the platform. Approximately 20 minutes later, a major explosion happened due to the rupture of the Tartan gas riser. This occurrence caused a massive and prolonged high pressure jet of flames that generated intense heat. At about 10 50 PM, another immense blast occurred that was believed to be a result of the rupture of the MCP-01 gas riser. Debris from this explosion was projected up to 800 m. away from the platform. Structural deterioration at the level below Module B had begun. This failure was accelerated by a series of additional explosions. One of these eruptions was caused by the fracture of the Claymore gas riser. Eventually, the vast majority of the platform collapsed. 

Proponents of the laboratories counter that, despite these shortcomings, the laboratories seiwe a vital mission of undertaking the high risk and expensive investments that the private sector would never agree to invest in. Although natural gas research and development was minimal, DOE support accelerated technological advances on natural gas-fired turbines. Much of the research and development at the laboratories has provided a net social benefit to the nation and economy, work such as safe nuclear reactors and the development of sophisticated defense weapons. 

Zinc in contact with wood Zinc is not generally affected by contact with seasoned wood, but oak and, more particularly, western red cedar can prove corrosive, and waters from these timbers should not drain onto zinc surfaces. Exudations from knots in unseasoned soft woods can also affect zinc while the timber is drying out. Care should be exercised when using zinc or galvanised steel in contact with preservative or fire-retardant-treated timber. Solvent-based preservatives are normally not corrosive to zinc but water-based preservatives, such as salt formulated copper-chrome-arsenic (CCA), can accelerate the rate of corrosion of zinc under moist conditions. Such preservatives are formulated from copper sulphate and sodium dichromate and when the copper chromium and arsenic are absorbed into the timber sodium sulphate remains free and under moist conditions provides an electrolyte for corrosion of the zinc. Flame retardants are frequently based on halogens which are hygroscopic and can be aggressive to zinc (see also Section 18.10). 

It was concluded that any candidate component can be produced using PM forging techniques at a cost at least 50 per cent lower compared with conventional forging processes. The accelerators were endurance-tested and exceeded all requirements in the standard room-temperature tests. The accelerators also withstood the test firing of more than 10,000 rounds at minus 65 degrees Fahrenheit with no failures being experienced... 

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