Flame Reactions and

Doring, p 630 of Report of German Bunsen Gesellschaft fur physikalische Chemie on Flame Reactions and Detonations at Trois-dorf.Oct 1956 and in Z Elektrochem 61, 5, pp 5 59-692(1957) 

Detonation (and Explosion), Flammability Characteristics of Combustible Gases and 

Detonation (Explosion, Flammability and Ignition). These subjects are discussed in the book of S.S. Penner B.P. Mullins, Explosions, Detonations, Flammability and Ignition , Pergamon Press, NY(1959) 

Detonotion, Flash-Across, Heat Pulse and Hypervelocity Phenomena. According to Cook (Ref 3), the phenomenon of heat pulse was first recognized by Dr W.S. McKewan of NOTS, China Lake, Calif while viewing microsecond, color, framing photographs of Nitromethane (NM) detonated thru SPHF (shock-pass-heat-filter) glass plates in experiments conducted by D.H. Pack, 

Cook (Ref 4). Their experiments in propagation of deton thru steel glass plates showed that thin plates of inert material invariably interrupt the deton wave completely, requiring the deton to re-form if it continues to propagate beyond the interrupter. A remarkable new phenomenon, called flash-across, was observed when a bluish-white hot spot on one frame and another hot spot that developed between adjacent frames on the opposite SPHF plate had both flashed across the chge and met at the collision interface 

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The carbon produced in the flame reaction, and which is subsequently removed as carbon suspension in water, amounts to 1.5 per cent by weight of the fuel oil feedstock charge. Some H2S present in the crude gas is removed by contact with the quench water. 

Flame Reactions and Detonations (Flammen-reaktionen und Detonationen, in Ger). Title of ihe Symposium (Diskussionstagung) held under the auspices of the Deutsche Bunsen-Gesellschaft fur physikalische Chemie at Troisdorf, Germany from 18 to 20 October,... 

W. Jost, Flammenreaktionen und Detonationen (Flame reactions and detonations), Introduction, pp 559—62... 

The retarding effect of HX, X, RX introduced into the flame may be of either physical or chemical nature (in either case, the residue R in RX is an extra fuel source). In the first case, the flame retardant reduces the oxygen concentration in the combustible mixture in the flame reaction zone by mere dilution, in the same way as added carbon dioxide or nitrogen. The heat capacity of the resultant mixture determines the amount of heat drained off for its heating. In the second case, the flame retardant directly participates in the flame reactions and affects the complex combustion process kinetics. The HX molecule is the main inhibiting particle. When RX is released into the gas phase of fuel-rich flames, HX is formed predominantly via RX -b H HX + RX, when Xj is released, HX is formed via X + H HX + X. 

A great profusion of ions (Fig. 14) and ion reactions occur in flames. The discussion is limited in this paper because the ion reactions are quantitatively unimportant with respect to other flame reactions and because there is no general agreement on the mechanism of these ionic reactions and hence no reliable chemical kinetics. This is an active field at present and it may be hoped in... 

The flame retardant system based on Si (3% wt.) and SnClj (2% wt.) incorporated into nylon-6,6 acts as an effective inhibitor of gaseous phase flame reactions and may be considered as a new type of nylon-6,6 flame protector. 

Corrosion Resistant Fiber-Reinforced Plastic (FRP). Fiber glass reinforcement bonded with furfuryl alcohol thermosetting resias provides plastics with unique properties. Excellent resistance to corrosion and heat distortion coupled with low flame spread and low smoke emission are characteristics that make them valuable as laminating resins with fiber glass (75,76). Another valuable property of furan FRP is its strength at elevated temperature. Hand-layup, spray-up, and filament-win ding techniques are employed to produce an array of corrosion-resistant equipment, pipes, tanks, vats, ducts, scmbbers, stacks, and reaction vessels for industrial appHcations throughout the world. 

Oxidizers. The characteristics of the oxidizer affect the baUistic and mechanical properties of a composite propellant as well as the processibihty. Oxidizers are selected to provide the best combination of available oxygen, high density, low heat of formation, and maximum gas volume in reaction with binders. Increases in oxidizer content increase the density, the adiabatic flame temperature, and the specific impulse of a propellant up to a maximum. The most commonly used inorganic oxidizer in both composite and nitroceUulose-based rocket propellant is ammonium perchlorate. The primary combustion products of an ammonium perchlorate propellant and a polymeric binder containing C, H, and O are CO2, H2, O2, and HCl. Ammonium nitrate has been used in slow burning propellants, and where a smokeless exhaust is requited. Nitramines such as RDX and HMX have also been used where maximum energy is essential. 

Antimony Oxide as a Primary Flame Retardant. Antimony oxide behaves as a condensed-phase flame retardant in cellulosic materials (2). It can be appHed by impregnating a fabric with a soluble antimony salt followed by a second treatment that precipitates antimony oxide in the fibers. When the treated fabric is exposed to a flame, the oxide reacts with the hydroxyl groups of the cellulose (qv) causing them to decompose endothermically. The decomposition products, water and char, cool the flame reactions while slowing the production and volatilization of flammable decomposition products (see Flaa retardants for textiles). 

Molybdenum trioxide is a condensed-phase flame retardant (26). Its decomposition products ate nonvolatile and tend to increase chat yields. Two parts of molybdic oxide added to flexible poly(vinyl chloride) that contains 30 parts of plasticizer have been shown to increase the chat yield from 9.9 to 23.5%. Ninety percent of the molybdenum was recovered from the chat after the sample was burned. A reaction between the flame retardant and the chlorine to form M0O2 012 H20, a nonvolatile compound, was assumed. This compound was assumed to promote chat formation (26,27). 

Chemical Factors. Because knock is caused by chemical reactions in the engine, it is reasonable to assume that chemical stmcture plays an important role in determining the resistance of a particular compound to knock. Reactions that produce knock are generally free-radical chain-type reactions which are different from those that occur in the body of the flame the former occur at lower temperatures and are called cool flame reactions. 

Solutions of these fire retardant formulations are impregnated into wood under fliU cell pressure treatment to obtain dry chemical retentions of 65 to 95 kg/m this type of treatment greatly reduces flame-spread and afterglow. These effects are the result of changed thermal decomposition reactions that favor production of carbon dioxide and water (vapor) as opposed to more flammable components (55). Char oxidation (glowing or smoldering) is also inhibited. 

For Hquid fuels, ignition delay times are of the order 50 ]ls at 700 K and 10 ]ls at 800 K. At low temperatures most of the ignition delay is the result of slow, free-radical reactions, and a distinction between the initiation and explosion periods within the ignition delay time can be made. With increasing ignition temperature for a given mixture, these times become comparable and at temperatures as high as 1500 K, both times may be of the order of lO " s. Consequently, the reaction zone in the flame of a mixture is observed to be one continuous event (12—14). 

Because of the unusual reactivity of the DCPD molecule, there are a number of wide and varying end use areas. The primary uses in the U.S. are DCPD-based unsaturated polyester resins (36%) hydrocarbon type resins, based on DCPD alone or with other reactive olefins (39%) EPDM elastomers via a third monomer ethylidenenorhornene or DCPD (16%) and miscellaneous uses (9%), including polychlorinated pesticides, polyhalogenated flame retardants, and polydicyclopentadiene for reaction injection mol ding (39). 

Definition of Dust E losion A dust explosion is the rapid combustion of a dust cloud. In a confined or nearly confined space, the explosion is characterized by relatively rapid development of pressure with a flame propagation and the evolution of large quantities of heat and reaction products. The required oxygen for this combustion is mostly supphed oy the combustion air. The condition necessaiy for a dust explosion is a simultaneous presence of a dust cloud of proper concentration in air that will support combustion and a suitable ignition source. 

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