Autoignition temperature , flame

The autoignition temperature is the minimum temperature required for self-sustained combustion in the absence of an external ignition source. The value depends on specified test conditions. Tht flammable (explosive) limits specify the range of concentration of the vapor in air (in percent by volume) for which a flame can propagate. Below the lower flammable limit, the gas mixture is too lean to burn above the flammable limit, the mixture is too rich. Additional compounds can be found in National Fire Protection Association, National Fire Protection Handbook, 14th ed., 1991. 

Some of the tests and criterion used to define fire resistance may be found in the Hterature (9). Additionally, the compression—ignition and hot manifold tests as defined in MIL-H-19457 and MIL-H-5606, respectively the Wick test as defined by Federal Standards 791, Method 352 flash point and fire point as defined in ASTM D92 autoignition temperature as defined in ASTM D2155 and linear flame propagation rate are defined in ASTM D5306 are used. 

Direct-Flame Incinerators. In direct-flame incineration, the waste gases are heated in a fuel-fired refractory-lined chamber to the autoignition temperature where oxidation occurs with or without a visible flame. A fuel flame aids mixing and ignition. Excess oxygen is required, because incomplete oxidation produces aldehydes, organic acids, carbon monoxide, carbon soot, and other undesirable materials. 

The ignition temperature or autoignition temperature is the minimum temperature of a flammable mixture that is required to initiate or cause self-sustained combustion without ignition from an external source of energy such as a spark or flame (ASTM D2155). 

PPS fiber has excellent chemical resistance. Only strong oxidising agents cause degradation. As expected from inherent resia properties, PPS fiber is flame-resistant and has an autoignition temperature of 590°C as determined ia tests at the Textile Research Institute. PPS fiber is an excellent electrical iasulator it finds application ia hostile environments such as filter bags for filtration of flue gas from coal-fired furnaces, filter media for gas and liquid filtration, electrolysis membranes, protective clothing, and composites. 

The autoignition temperature is the minimum temperature for a substance to initiate self-combustion in air in the absence of a spark or flame. The temperature is no lower than and is generahy considerably higher than the temperature corresponding to the upper flammabihty limit. Large differences can occur in reported values determined by different procedures. The lowest reasonable value should be accepted in order to assure safety. Values are also sometimes given in oxygen rather than in air. 

The combustion characteristics of liquid fuels are similarly determined by measures of their ability to sustain a flame. Two measures of the combustion characteristics of liquid fuels especially related to safety are flash point and autoignition temperature. The flash point is the maximum temperature at which a liquid fuel can be maintained in an open vessel exposed to air before which it will sustain a flame... 

Flashpoints (the reason for the plurality is explained in paragraph 1.3) have the advantage of being linked to the boiling point, the pressure and the lower explosive limit. This is the reason why flashpoints are such important parameters in the evaluation of the inflammability risk of a liquid or a solid. The measurement of flashpoints implies the existence of an ignition flame for the gaseous mixture. Nevertheless, contact of a suitable substance-air mixture with a hot surface can be sufficient to start the combustion of the mixture. The autoignition temperature is the parameter that determines the possibility that an inflammable material will combust in contact with a hot substance without the presence of a flame. 

Autoignition temperature is the temperature at which a substance bums up in the absence of any inflammation source (flame, spark). ... 

Fuel LHV HHV (MJ/kg) (MJ/kg) Stoichiometric Air/Fuel Ratio (kg) Combustible Range(%) Min. Flame Ignition Autoignition Temperature (°C) Energy (MJ) Temperature (°C) ... 

For remote ignition under autoignition conditions, direct flame heating is small or zero, so the critical compartment temperature needs to be greater than or equal to the autoignition temperature, e.g. about 400-600 °C for common solid fuels. 

Autoignition Temperature (AIT) - The lowest temperature at which a flammable gas or vapor-air mixture will ignite from its own heat source or a contracted heat source without the necessity of a spark or flame. 

Hydraulic fluids usually exhibit a consistent response of smoke color, flame color, autoignition temperature, and a whitish residue. 

Melt and autoignition temperatures for many materials are known, as are normal flame temperatures. Table 8-1 gives selected temperatures of interest to many investigators. Soot will normally not affix itself to surfaces at more than approximately 700°F (371°C). Therefore, areas of high fire intensity may have little or no soot deposits. Flame temperatures are... 

Carbon monoxide is a highly flammable and poisonous gas. Its flammable limits in air are 12.5 to 74.2% by volume, and the autoignition temperature 700°C. It explodes when exposed to flame. Reactions with interhalogen compounds, such as, bromine pentafluoride or halogen oxides can cause explosion. It forms explosive products with sodium or potassium that are sensitive to heat and shock. 

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