Material vapor generation

The generation of material vapors can be quantified in terms of 1) relationship between weight loss and sample temperature. AMTL used thermogravimetric techniques for such quantification (J ), and 2) the relationship between the generation rate of material vapors and the heat flux. Factory Mutual Research Corporation (FMRC) has developed a technique using FMRC s Small-Scale Flammability Apparatus (2-10), which was used for the quantification. 

Generation of Material Vapors. The magnitude of heat required to generate vapors from a material depends on the thermal stability of the material. As the temperature or heat flux is increased, generation rate of vapors, measured in terms of mass loss of the material, increases and the following relationship is satisfied (2,3) ... 

Small areas Collect the agent using a vacuum cleaner. Place the collected material into containers lined with high-density polyethylene. Wash the area with copious amounts of soap and water. Collect and containerize the rinseate in containers lined with high-density polyethylene. Ventilate the area to remove any agent vapors generated during the decontamination. 

Avoid feeding a material to a reactor at a higher temperature than the boiling point of the reactor contents. This can cause rapid boiling of the reactor contents and vapor generation. 

Hazards of Combustion Products Irritating vapors generated when heated Behavior in Fire Not pertinent Ignition Temperature (deg. F) 706 (est.) Electrical Hazard Not pertinent Burning Rate 1.1 mm/rnin. Chemical Reactivity Reactivity with Water No reaction Reactivity with Common Materials No reaction Stability During Transport Stable Neutralizing Agents for Acids and Caustics Flush with water Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

When a combustible material is exposed to an external radiant heat source, its surface temperature starts to rise. The temperature inside the solid also increases with time, but at a slower rate. Provided the net heat flux into the material is sufficiently high, the surface temperature eventually reaches a level at which thermal decomposition begins. The fuel gases and vapors generated emerge through the exposed surface and mix with air in the gas phase. Under certain conditions, this mixture exceeds the lower flammability limit and ignites. 

Modify the process to reduce the consequences of a release for example, use refrigerated rather than pressurized storage, which results in higher liquid release and lower vapor release rates (from the same hole size) and lower vapor generation rates from a pool dilute hazardous materials with inert or less hazardous material to reduce partial pressure or reduce operating pressures to reduce release rates. 

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