JOURNAL OF FIRE SCIENCES

Characterization of Stovetop Cooking Oil Fires
Hamins A, Kim SC and Madrzykowski D
A series of cooking fire experiments were conducted by the National Institute of Standards and Technology (NIST) to examine the hazard associated with cooking oil fires. First, a series of twelve experiments were conducted on a free-standing stove situated in the open. The experiments were based on scenarios outlined in the draft UL 300A standard for fire suppression apparatus. Both gas and electric ranges were tested. The amount of oil and types of cooking pans were varied in the experiments. Oil was heated on a cook top burner until autoignition took place. Measurements of oil and pan temperatures, heat release rates, and heat fluxes characterized the hazard of the ensuing fires. Next, two experiments were conducted using a full-scale residential kitchen arrangement to examine the hazard associated with the free burning oil fires situated within a compartment equipped with commercial furnishings, fiberboard cabinets, and countertops. The dimensions of the test room were 3.6 m × 3.4 m × 2.4 m high. Corn oil was heated on a cook top burner until autoignition took place. Measurements of room temperatures, heat fluxes, and heat release rates showed that even small cooktop fires spread and grew ultra-fast within the kitchen compartment.
Bench-Scale Test Facility for Evaluating the Performance of Thermal Imagers for Fire Service Applications
Kim SC and Hamins A
A bench-scale facility was developed for the evaluation of thermal imaging cameras. Smoke obscuration conditions in the optical smoke cell were characterized by measuring laser light transmittance through the cell. Measurements showed that the laser transmittance along the axial direction of the optical smoke cell was relatively uniform in the upper and lower halves of the cell for various smoke obscuration conditions. The thermal sensitivity of thermal imagers was investigated using the Michelson Contrast (CM) as a performance metric for a bar target viewed through the smoke-filled cell for different background thermal conditions. The results of the study indicate that the optical smoke cell can be utilized as a well-controlled and effective bench-scale test apparatus to evaluate aspects of the performance of thermal imagers for fire service applications.
Numerical and experimental investigation of carbon monoxide spread in underground mine fires
Zhou L, Yuan L, Bahrami D, Thomas RA and Rowland JH
The primary danger with underground mine fires is carbon monoxide poisoning. A good knowledge of smoke and carbon monoxide movement in an underground mine during a fire is of importance for the design of ventilation systems, emergency response, and miners' escape and rescue. Mine fire simulation software packages have been widely used to predict carbon monoxide concentration and its spread in a mine for effective mine fire emergency planning. However, they are not highly recommended to be used to forecast the actual carbon monoxide concentration due to lack of validation studies. In this article, MFIRE, a mine fire simulation software based on ventilation networks, was evaluated for its carbon monoxide spread prediction capabilities using experimental results from large-scale diesel fuel and conveyor belt fire tests conducted in the Safety Research Coal Mine at The National Institute for Occupational Safety and Health. The comparison between the simulation and test results of carbon monoxide concentration shows good agreement and indicates that MFIRE is able to predict the carbon monoxide spread in underground mine fires with confidence.
The Evolving Temperature Field in a 1 m Methanol Pool Fire
Chen J, Sung K, Wang Z, Tam WC, Lee KY and Hamins A
Thin filament pyrometry is used to measure the time-varying temperature field in a 1 m methanol pool fire. A digital camera with optical filters and zoom lens recorded the emission intensity of an array of 12 μm Silicon-Carbide filaments oriented horizontally at various heights across the steadily burning pool fire. A 50 μm diameter thermocouple measured the temperature at locations corresponding to the filament positions. A correlation was developed between the local probability density functions of the thermocouple time series measurements corrected for radiation and thermal inertia effects and the camera grayscale pixel intensity of the filaments. A regression analysis yields the local mean temperature and its variance. The time series of the temperature field is transformed into average values during consecutive phases of the fire's puffing cycle, providing quantitative insight into the complex and dynamic structure of a turbulent fire.