Ethylene flammability limits

Figure 16. Flammable limits for methane, ethylene, benzene, with nitrogen, carbon dioxide and water vapor.

Both LFL and UFL valnes for mixtnres can be estimated by nse of the Le Chatelier eqnation (Growl and Lonvar 1990). However, the methods have some limitations with respect to calcnlating the UFL for certain mixtnres. Britton (1996) determined that the eqnation does not apply to the UFL of mixtnres containing decomposable components snch as ethylene oxide or to mixtnres containing ethyl ether. Mashnga and Growl (2000) discnss the derivation of Le Chatelier s mixing rnle for flammable limits. 

Vanta et al (Ref 2) determined the detonation limits of propylene oxide/air mixts to be 2.7 to 14.4 volume %, or much narrower than the flammability limits of ethylene oxide/air (see Table 3). They also measured the lower detonation limit for n-propyl nitrate/air and found it to be 2.2 volume %... 

Eggleston, Herrera, and Pish 1976 To provide needed data about the use of air entrained by a water spray to dilute flammable vapor releases below the lower flammability limit. Absorption/adsorption effects are insignificant in the case of ethylene and vinyl chloride. Sprinklers and water-spray nozzles vary widely in their efficiency as air movers. Flame quenching was not affected in any of the experiments Water sprays increased the rate of flame propagation. The air-pumping action of a water curtain can be used to set up a barrier to the horizontal flow of vapors. 

Careful attention has been given to the oxygen level in the reactor effluent and recycle gases. Experimental determinations were made, under severe ignition conditions, of flammability limits for these ethylene-and oxygen-bearing gases at actual process temperature, pressure, and... 

The ethylene oxidation rate is proportionhUo the oxygen concentration. This means that the air-to-ethylene ratio has a predominant influence on the conversion and yield. For practical purposes, however, the optimal ethylene concentration is determined by the flammability limits of the mixtures with oxygen or air, and by the olefin loss in tbe off-gases. 

BROMOMETHANE (74-83-9) Combustible gas, but not easily ignited it has narrow flammability limits in air (10—16% by volume in air). The sensitivity of these limits may be widened by pressure, oxygen, aluminum, magnesium, zinc, and their alloys. Reacts with water. Attacks aluminum to form pyrophoric alkyl aluminum salts. Incompatible with strong oxidizers, metals, dimethylsulfoxide, ethylene oxide, water. Attacks zinc, magnesium, alkali metals, and their alloys. Attacks some plastics, rubber, and coatings. 

ETHYLENE FLUORIDE (75-37-6) Flammable gas (flammability limits 3.7-18% by volume in air). Violent reaction with strong oxidizers, barium, sodium, and potassium. Incompatible with powdered aluminum, liquid oxygen, potassium,. sodium. May form explosive compounds with divalent light metals and metallic azides. Attacks some metals in the presence of moisture. Undergoes thermal decomposition when exposed to flame or red-hot surfaces. Flow or agitation of substance may generate electrostatic charges due to low conductivity. 

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