Definition of the concentration gradient above flammable liquids
We surveyed construction and operation-in-area codes concerned with the spill potential of flammable liquids that generate heavy vapor and the separation between these liquids and ignition sources. Our survey showed that acceptable separation distances between potential spill surfaces and ignition sources have increased over the years, intuitively on the name of safety. In order to understand the reasoning behind this, we inaugurated literature and experimental research. Our literature research revealed theoretical relationships that include a case for evaporating fluids with boundary conditions of diffusion of the volatile vapor through a stagnant gas film. In enclosed containers with open tops, the calculated vapor concentration gradients are monotonic and directly proportional to the fluid vapor pressure. To assess the validity of these calculated values, we performed experiments to determine the elevations at which flammable mixtures formed above the surfaces of low-volatility, high-vapor-density liquids. The tests involved vaporizing heptane and octane into long, open-ended tubes and then determining the heights at which the lower flammability limits were reached. Our results showed that the process does conform to the theoretical relationships we found in our literature search. 11 references, 4 figures.
- Research Organization:
- Lawrence Livermore National Lab., CA (USA); Puerto Rico Univ., Mayaguez
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 5080339
- Report Number(s):
- UCRL-89723; CONF-840689-1; ON: DE84008296
- Resource Relation:
- Conference: ASTM/SFPE symposium on application of fire science to fire engineering, Denver, CO, USA, 26 Jun 1984; Other Information: Portions are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Anomalously high flammability of low volatility fuels due to anomalously low ignition temperatures
Anomalously high flammability of low volatility fuels due to anomalously low ignition temperatures
Related Subjects
99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
GAS SPILLS
EVAPORATION
OIL SPILLS
FLAMMABILITY
VOLATILITY
COMBUSTION PROPERTIES
PHASE TRANSFORMATIONS
500200* - Environment
Atmospheric- Chemicals Monitoring & Transport- (-1989)
570000 - Health & Safety