Direct-firing 464 INDEX

Other important properties include Hash point, volatility, viscosity, specific gravity, cloud point, pour point, and smoke point. Most of these properties are related directly to the boiling range of the kerosene and are not independently variable. The flash point, an index of fire hazard, measures the readiness of a fuel to ignite when exposed to a flame. It is usually mandated by law or government regulation to be 120° or 130° F (48° or 72° C), Volatility, as measured... 

The Finnish legislation (Pyotsia, 1994) classifies the flammability of chemical substances on the basis of their flash and boiling points. This is similar to the European Union Directives concerning hazardous substances. Also the Dow Fire and Explosion Index (1987) and Edwards Lawrence (1993) have been used similar approaches. 

Predictive hazard evaluation procedures may be required when new and different processes, designs, equipment, or procedures are being contemplated. The Dow Fire and Explosion Index provides a direct method to estimate the risks in a chemical process based upon flammability and reactivity characteristics of the chemicals, general process hazards (as exothermic reactions, indoor storage of flammable liquids, etc.) and special hazards (as operation above the flash point, operation above the auto-ignition point, quantity of flammable liquid, etc.). Proper description of this index is best found in the 57-page Dows Fire and Explosion Index, Hazard Classification Guide, 5 th ed., AIChE, New York, 1981. 

The degree of flammability of a polymeric material may be predicted from its chemical structure. One of the most valuable criteria in fire research, the so-called limiting oxygen index (LOI) may be estimated either from the specific heat of combustion or from the amount of char residue on pyrolysis. Since both quantities can be determined if the chemical structure is known, also the LOI can be estimated. An approximate assessment of the LOI value direct from the elementary composition of the polymer is also possible. 

Immediately isolate an area around the fire for at least 200 feet in all directions. If possible, identify the agent and develop a downwind hazard diagram (see Agent Index). Adjust the initial isolation distance as appropriate. Based on the size of the fire, the amount of material aerosolized and local conditions (e.g., weather, population density, time of day), shelter-in-place until the initial cloud passes may be the most appropriate course of action since timely evacuation of the threatened downwind population may not be possible. 

A fired reboiler control S3rstem using the Wobbe index is shown in Fig. 17.3. The density meter should be installed directly in the fuel gas hne, downstream of the knockout drum and any points where fiiel gas streams are added, and where it would be unaffected by vibrations (370). 

The limited oxygen index (LOI) is the minimum O2 concentration at or below which there is no downward fire propagation for a vertical polymer sheet inside a glass cylinder, with gas flowing in an upward direction. In the test, 70- to 150-mm (2.8- to 5.9-inch) long, 6.5-mm (0.26-inch) wide, and 3-mm (0.12-inch) thick vertical polymer samples are ignited at the top and fire propagafes in a downward direction. 

Risk phrases representing hazards not directly related to this Guide (e.g., inhalation, environment, and fire) have not been considered in the Chemical Index. In the following links you will find the complete list of risk phrases http //www.hse.gov.uk/chip/ phrases.htm... 

---