Ignition temperature of liquids

Many articles have described the measurement of spontaneous ignition temperatures of various fuels and pure hydrocarbons by a variety of methods (11,25,31, 44> 63, 85, 86). Jackson gives the spontaneous ignition temperatures of 94 pure hydrocarbons and 15 fuels and commercial fluids. He states that benzene has the highest value of any of the materials tested (42). A comprehensive survey of methods of determining spontaneous ignition temperatures of liquid fuels and a tabulation of data is given by Mullins (64). 

ASTM E659-78. Standard Test Method for Auto-ignition Temperature of Liquid Chemicals, ASTM International West Conshohocken, PA, USA, 2000 Edition. 

Fig. 3.17 Scheme of the measurement of self-ignition temperature of liquids and gases according to DIN 51 794-1978. Dimensions in mm... 

G 72 Standard Test Method for Autogenous Ignition Temperature of Liquids and Solids in a High-Pressure Oxygen-Enriched Environment... 

Autoignition Temperature (AIT) The auto ignition temperature of a substanee, whether solid, liquid, or gaseous, is the minimum temperature required to initiate or eause self-sustained eombustion, in air, with no other souree of ignition. 

Another important ether is vinyl ether, a colorless liquid with the characteristic ether odor. Its molecular formula is CjHjOCjHj. Vinyl ether has a flash point of -22°F and an ignition temperature of b80°F. It is highly toxic by inhalation and is used in medicine and in the polymerization of certain plastics. 

The next most common ketone is methyl ethyl ketone, commonly referred to as MEK. Its molecular formula is CH3COC2H5. MEK has a flash point of 24°F and an ignition temperature of 960" F. It is a colorless liquid with a characteristic ketone odor. It is as widely used as acetone and is almost as hazardous. 

Setchkin, N.P., Self-ignition temperature of combustible liquids, J. Research, National Bureau of Standards, 1954, 53, 49-66. 

Also, the spontaneous ignition temperature for liquid or volatile oxidizers can be investigated by testing [157]. Here, a predetermined quantity of sawdust (12 to 50 mesh) is added to a reaction vessel and brought to the desired test temperature. The liquid oxidizer is then cautiously injected with a long hypodermic syringe into the vessel. The extent of reaction is determined from continuous temperature measurements and by visual observations. 

The next aldehyde is acetaldehyde, a colorless liquid with a pungent taste and a fruity odor. Its molecular formula is CH,CHO. It has a flash point of -40°F, an ignition temperature of 340°F, and is toxic by inhalation. Acetaldehyde is used in die manufacture of many other chemicals. Other important aldehydes are propionaldehyde, butyraldehyde, and acrolein. 

Residue Heatup, Equations 27—30 can be used to estimate the time for residue heatup, T., by replacing the liquid properties, such as density and heat capacity, with residue properties, and considering the now smaller particle in evaluating the expressions for Re < ), and In the denominator of kp Td,0is replaced by T, and is replaced by T the ignition temperature of the residue. 

The auto-ignition temperatures of various halogenated hydrocarbons in presence of chlorine are considerably below the corresponding values in air. Examples are (in °C) chloromethane 215 (618 in air) dichloromethane 262 (556) 1,2-dichloropro-pane 180 (555°C). Flammability limits are usually wider in chlorine than in air. Gaseous mixtures of chloromethane and chlorine are detonable in the range 12.5— 55% [1]. Liquid mixtures of dichloromethane and chlorine may well also be detonable [2]. 

Table XXIII although by no means complete gives the values obtained by a variety of methods for ignition temperatures of a number of the more common combustible liquids, and furnishes a basis of comparison.

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