Firing Pool

Potential explosion phenomena include vapor cloud explosions (VCEs), confined explosions, condensed-phase explosions, exothermic chemical reactions, boiling liquid expanding vapor explosions (BLEVEs), and pressure-volume (PV) ruptures. Potential fire phenomena include flash fires, pool fires, jet fires, and fireballs. Guidelines for evaluating the characteristics of VCEs, BLEVEs, and flash fires are provided in another CCPS publication (Ref. 5). The basic principles from Reference 5 for evaluating characteristics of these phenomena are briefly summarized in this appendix. In addition, the basic principles for evaluating characteristics of the other explosion and fire phenomena listed above are briefly summarized, and references for detailed evaluation of characteristics are provided. 

Flammability Vessel/enclosuie rupture following ignition of contained vapors + air Vapor cloud explosion Flash fire Pool fire... 

The outputs of an event tree from a post-release frequency analysis are a number of outcomes ranging from more to less hazardous. An event tree highlights failure routes for which no protective system can intervene and where additional protective systems/mitigative action may be contemplated. The quantitative output is the frequency of each event outcome. These outcomes (which might specify BLEVE, flash fire, pool fire, jet fire) are used to determine individual and societal risk. 

Explosive charges are placed on the munition, which is then submerged into the center of the pool, and the explosive charges are detonated. The munition is converted into fragments and the burster is exploded. The pool is designed to withstand multiple explosions, and it is expected that one weapon can be destroyed every 15 minutes. From laboratory-scale experiments, it was concluded that a firing pool with a 12-meter diameter and a 6-meter depth, filled with approximately 500 cubic meters of aqueous decontamination... 

No mention of the development of the firing pool technology past the bench scale was found in the literature. The firing pool technology was not considered further by the committee because it had not been further developed and because of the problems that were uncovered during the bench-scale studies. 

Fire - Pool Fire Fire - Flash Fire... 

Thermal radiation flux for fires (for a jet fire, pool fire, or fireball)... 

Thermal Radiation Effects. Thermal radiation effects arise from flash fires, pool fires, jet fires, or fireballs. These involve the combustion of flammable mixtures. The intensity of thermal radiation (measured in terms of thermal radiation flux or energy per unit area and time) at a receptor outside a fire depends on its distance from the Are, the flame height, flame emissive power, and atmospheric transmissivity. 

Flash and evaporadon Dispersion Neutral or posidvely buoyant gas Dense gas Fires Pool fires Jet fires BLEVES Flash fires Explosions Confined eiqilosions Unconfined vapor cloud explosions (UVCE) Physical explosions (PV) Dust explosions Deionadons Condensed phase detonadons Missiles Consequences Effect analysis Toxic effects Thermal effects Overpressure effects Damage assessments Community Workforce Environment Company assets... 

Pool Fire The combustion of material evaporating from a layer of liquid at the base of the fire. 

POOL FIRE A fire involving a flammable liquid spillage onto ground or onto water, or within a storage tank or treneh. The pool size depends upon the seale and loeal topography. Fire engulfment and radiant heat pose the main risks. 

The fire spreads easily by, e.g., running liquid fire, a pool fire, a fire ball, heat radiation or thermal lift (convection). 

Burning Rate - Defined as the rate (in millimeters per minute) at which a pool of liquid decreases as the liquid bums. Details of measurements are provided by D. S. Burgess, A. Strasser, and J. Grumer, Diffusive Burning of Liquid Fuels in Open Trays, Fire Research Abstracts and Reviews, 3, 177 (1961). 

The heat flux, E, from BLEVEs is in the range 200 to 350 kW/m is much higher than in pool fires because the flame is not smoky. Roberts (1981) and Hymes (1983) estimate the surface heat flux as the radiative fraction of the total heat of combustion according to equation 9.1-32, where E is the surface emitted flux (kW/m ), M is the mass of LPG in the BLEVE (kg) h, is the heat of combustion (kJ/kg), is the maximum fireball diameter (m) f is the radiation fraction, (typically 0.25-0.4). t is the fireball duration (s). The view factor is approximated by equation 9.1-34. where D is the fireball diameter (m), and x is the distance from the sphere center to the target (m). At this point the radiation flux may be calculated (equation 9.1-30). 

Gregory, W.S., et al., 1989, FIRAC Code Predictions of Kerosene Pool Fire Tests, (Unpublished Report), LANL, May. 

Gritzo, L. A, et al., 1995a, Heat Transfer to the Fuel Surface in Large Pool Fires, Transport Phenomenon in Combustion, S. H. Choa (ed.), Taylor and Francis Publishing, Washington, DC. 

Gritzo, L. A. et al., 1995, Wind-Induced Interaction of a Large Cylindrical Calorimeter and an Engulfing JRE Pool Fire, Symposium on Thermal Science Engineering in Honor of C. L. Tien, Berkeley, CA, November 14. 

Holen, J., M. Brostrom, and B. F. Magnussen, 1990, Finite Difference Calculation of Pool Fires, Pmc of 23rd Int. Symp, Combustion, pp. 1677-1683. 

Tatem, P. et al., 1982, Liquid Pool Fires in a Complete Enclosure, 1982, Tecf --- —... 

Section 1.4.4 describes two leaks onto pools of water that spread much farther than anyone expected. One was ignited by a welder 20 m away, and the other spillage, onto a canal, caught fire 1 km away. 

This fire occurred some years ago because those concerned did not fully appreciate the difference in behavior between liquid hydrocarbons, such as naphtha or gasoline, and LFGs. The vapor from a spillage of gasoline will spread only a short distance—about the diameter of the pool. But the vapor from a spillage of LFG can spread for hundreds of meters. 

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