Smouldering fires

Recent research has resulted in the development of carbon monoxide detectors. They are most effective in detecting slow smouldering fires where high levels of carbon monoxide are produced before there is any smoke. They are not intended as replacements for smoke detectors but as an addition to the range. 

Example F Extinguishing Smouldering Fires in Waste-Incineration Bunkers... 

Smouldering fires can occur in many sites, such as coal-dust storage, com silos or wood-chip silos in chipboard factories. Conventional methods of fire-extinguishing often fail in these types of situation, mainly because neither water (with or without additives), foam nor powder can reach the fire if it is deep within a pile of stored material. Gas-extinguishing is then the method of choice. 

Fire-extinguishing methods for a smouldering fire may be differentiated as follows ... 

This comparison shows that CO2 provides clear advantages for the fighting of smouldering fires in container like waste-incineration bunkers (see Fig. 6.18). 

It is appropriate also to consider the effects of a smouldering fire which only occur in porous materials such as paper, cardboard, sawdust, fibreboard, etc. (carbonaceous). 

The use of fire retardants in polymers has become more complicated with the realisation that more deaths are probably caused by smoke and toxic combustion products than by fire itself. The suppression of a fire by the use of fire retardants may well result in smouldering and the production of smoke, rather than complete combustion with little smoke evolution. Furthermore, whilst complete combustion of organic materials leads to the formation of simple molecules such as CO2, H2O, N2, SO2 and hydrogen halides, incomplete combustion leads to the production of more complex and noxious materials as well as the simple structured but highly poisonous hydrogen cyanide and carbon monoxide. 

Flame retardants - Fire retardants - Smoulder retardants -Smoke-suppressants Flexibilisers Flow improvers... 

A smouldering bag in a pesticide warehouse, believed to be of this, led to an explosion, killing three firemen, and fire which took six days to extinguish (possibly because of caution concerning anti-cholinesterase toxicity). This is a moderately high energy compound by virtue of the triazene function. Other pesticides present were of less energetic structure. 

A fire involving foam rubber mattresses in a storeroom led to an unexpected and serious explosion. Subsequent investigation showed that an explosion risk may exist when the flammable smoke and vapour from smouldering of large amounts of foam rubber are confined in an enclosed space. Suitable strict precautions are recommended [1], Methods of quantitatively evaluating potential fire hazards from release rates of heat, smoke and toxic gases from heated foam rubber and plastics materials were developed, and their application to real situations discussed [2],... 

Moisture content. The importance of maintaining a low moisture content for either dried loose pulp or pellets has been documented Q). Fire or smouldering is a distinct danger in feed mill operations or storage facilities and usually occurs when the moisture content of the dried products exceeds the recommended 10%, moisture level. 

He was their deepest and darkest and most loved DJ yet unwilling to transact when it came to his music and so remained cloistered inside his queer family. Oblivious to the familiar he charged out sets that smouldered and menaced rising from the dancefloor like a fire. A quiet man in life, in music he was abrasive, joyous and free, painting views you had to fall into head heart and body all at once. Any noise that could be reignited came into his music, revving motors crazed laughter political rhetoric and animal sounds. 

Dusts. Most combustible solids can produce combustible dusts. Combustible dusts are particularly hazardous they have a very high surface area to volume ratio. When finely divided as powders or dusts, solids bum quite differently from the original material in the bulk. Dust and fiber deposits can spread fire across a room or along a ledge or roof beam very quickly. Accumulations of dust can smoulder slowly for long periods, giving little indication that combustion has started until the fire suddenly flares up, possibly when no one suspects a problem. 

Even now, in the stillness of death, the huge jaws seemed to be dripping with bluish flame, and the small, deep-set, cruel eyes were ringed with fire. I placed my hand upon the glowing muzzle, and as I held them up my own fingers smouldered and gleamed in the darkness. 

Despite the risk of reignition of a solvent fire from smouldering wood, it is on balance safer to store drums on pallets. A stack of palletized drums is more stable, particularly if the ground is at all uneven. Palletized drums are less prone to damage in handling by fork-lift truck than when handled loose, even if specialized drum handling attachments are used and in an emergency pallets can be handled more quickly. Finally, in a bunded area where rainwater may accumulate the base of a drum may be corroded whereas it is rare for a pallet to rot under the same conditions. 

The failure of electrical appliances or fixtures can initiate smouldering, which conld lead to localised fires, snch as are simulated in, for example, DEN EN 60695-11-5 [13], through, for example, flame exposure from a Brmsen burner. Depending on the application (TV cabinets, cables and so on), other fire sources are used. 

All materials employed in electronic equipment operating under electrical load have to be flame retardant. Traditional printed circuit boards utilise epoxy resins retarded by reacting TBBA into the liquid resins before laminate constmction (FR4). To comply with UL94 V-0 specification, the resins contain about 20% of bromine. In case of fire or smouldering, brominated epoxies evolve corrosive decomposition products that can damage the surrounding electronic equipment. This can be avoided by use of phosphoms flame retardants. 

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