Cooking Oil Fires Research Articles

Household cooking oil use and its bearing on fire safety

Cooking oil fires present a reasonable worst-case hazard when considering thermal radiation to occupants close to a kitchen hob/cooktop. Shallow or deep frying, the activity frequency and the oil volume may contribute to the risk. A review of cooking oil use is presented via consumer purchasing habits, studies on the health effects of cooking with oil and statistics related to the disposal of cooking oil waste. An online survey provides further data on current cooking practices. Olive oil, vegetable oil or pure sunflower appear to be the most common types. Results suggest that cooking on a hob occurs 4 times per month for deep frying and 17 times per month for shallow frying. A design value of 250 mL is advocated for all frying activities with a frequency of 11 times per month. Design volumes of 2.5 L and 150 mL are proposed for deep and shallow frying, respectively.

Identification of triglycerides in liquid and fire debris samples by triple quadrupole liquid chromatography-mass spectrometry.

Analysis of fire debris for triglyceride-based oils may be of interest to fire investigators depending on the circumstances of a particular fire. Such circumstances include accidental or intentionally set cooking oil fires, fires involving triglyceride-based "eco" fire log products, and spontaneous ignition fires that involve drying oils on rags. Many forensic laboratories utilize gas chromatography-mass spectrometry following fatty acid methyl esterification to identify triglyceride residues in fire debris extracts. This study explores an alternate approach, which involves the identification of intact triglycerides by liquid chromatography-mass spectrometry-mass spectrometry (LC-MS/MS). 52 triglyceride-based oils and fats (22 different types) were analyzed by LC-MS/MS using multiple reaction monitoring to investigate variation in triglyceride content between different brands and types of oil and fat. Selected oils were then degraded by exposure to air, typical cooking conditions and/or fire conditions to simulate samples that are typically encountered by Fire Debris Analysts in fire investigation cases. Triglycerides were identified in all pristine and degraded oil samples, and relative peak areas for degraded samples often resembled their pristine oil counterparts. In samples where relative peak area differences were noted, more predominant degradation was observed for triglycerides with a higher proportion of poly-unsaturated fatty acids. Variability in triglyceride content between different brands and types of oil are discussed, as well as factors affecting the identification of triglyceride peaks in commercial oil samples, as compared to the corresponding analytical standard.

Characterization of Stovetop Cooking Oil Fires.

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.

Performance evaluation of water mist with additives in suppressing cooking oil fires based on temperature analysis

Cooking oil fires which happened in the kitchen or hotel have become quite popular over the last decades. Compare to other types of fires, cooking oil fires are very difficult to extinguish. Both foam and powder can effectively extinguish the flames over the oil surface but they are very difficult to cool the oil below its auto-ignition temperature and to prevent it from re-ignition due to their limited cooling capacity. Moreover, water mist with additives may be applied to provide additional improvements in terms of suppression effectiveness and temperature control of cooking oil fires. The present work establishes a series of home-scale experiments to study extinguishing mechanisms and effectiveness of pure water and water mist with additives against cooking oil fires. The thermal transient within the test chamber has been evaluated during the fire development as the main quantitative parameter. Results showed that water mist is shown to be efficient in cooking oil fires control, especially endowed with the chosen additives which demonstrated that water mist with additives would extinguish cooking oil fires through physical and chemical mechanisms. Furthermore, the change in fire extinguishing efficiency differs for different additives and mass fractions of the additives.

Experimental Evaluation on Performance of Open Kitchen Fire Suppression Systems

Experiments with burning cooking oil in open kitchen fires are reported in this paper. Heat release rate, flame temperature, burning duration and heat fluxes of cooking oil fires were measured. Performances of water mist and gas-solid composite dry powders in suppressing cooking oil fires were evaluated by experiments. Reduction in gas temperature distributions, changes in heat fluxes and suppression time were then measured. Experimental data will provide necessary information for hazard assessment of open kitchen in the residential units of tall buildings.

The Experimental Study on Extinguishing Cooking Oil Fires by Water Mist

Abstract. The effects of flow coefficients, working pressures and different spray distances on extinguishing cooking oil fires by water mist were studied by experiment. The results show that the fire suppression effectiveness is increased with the increase of flow coefficient and working pressure, spray distance also affects the fire extinguishment efficiency of water mist. Reasonable conditions and designing parameters for practical engineering application of water mist are suggested.

CONCEPT DESIGN AND TESTING OF MULTI-NOZZLE WATER MIST FIRE SUPPRESSION SYSTEM

In this work a flexible design of multi-nozzle arrangement of water mist fire suppression system was studied. The source of fire was a 65 mm diameter cooking oil fire. An investigation on the impact of nozzle arrangement on the temperature profile of fires was conducted. The occurance of oil splash due to the application of water mist was also studied. The water mist systems developed in the present work can effectively extinguish cooking oil fires and prevented them from re-ignition. The spray angle, discharge pressure, and water flow rate were important factors to determine the effectiveness of water mist in extinguishing cooking oil fires.

Experimental Study of New Gas-Solid Composite Particles in Extinguishing Cooking Oil Fires

New gas—solid composite particles appropriate for extinguishing cooking oil fires will be reported in this article. This powder product is composed of zeolite 13X particles of diameter 1—2 μm and absorbed 2-bromo-3,3,3-trifluoropropene. The preparation and physicochemical properties of the composite particles will be reported. Their performance and possible mechanism in extinguishing cooking oil fires are then investigated with full-scale burning tests. Experiments were carried out in a room of length 3 m, width 3 m, and height 3 m. A cooking oil pool fire of diameter 0.25 m was ignited by ethanol and burnt inside the room. Different dry powder products were also evaluated. Their suppression effect was compared with that of this new product. Results indicated that the new composite particles have better performance in extinguishing cooking oil fires in comparison with other dry powder tested. Relatively shorter extinguishing time was achieved with smaller amount of agents required without any re-ignition. The new composite particles give better performance in suppressing cooking oil fires because of highly efficient free flame radical scavengers, improved cooling capacity, hydrophobic and oleophobic surface. Chemical suppression effects are reported.

Cooling characteristics of hot oil pool by water mist during fire suppression

Generally water is not favored for use in suppressing hot liquid fuel fires due to concerns of vapor explosion and boil-over, which could present potential danger to nearby personnel or firefighters. This paper reports on a series of full-scale fire experiments in which water mist was used in extinguishing large hot cooking oil fires. It was shown that water mist not only extinguished large fires effectively but also cooled hot oil from its ignition point (up to 360 °C) to below its flash point (200 °C) in a short period of time and prevented the fire from re-igniting. No vapor explosion was observed in the experiments when water droplets touched the hot oil whose temperature was higher than the superheat-limited temperature of water. A boiling layer of mixed bubbles, water droplets and oil was formed in the hot oil after all flames were extinguished, as water droplets boiled, bubbled and expanded in the hot oil. No boil-over or spillage of the oil over the container was observed in the experiments when water mist was discharged into the oil at high temperature (>300 °C) but boil-over did occur in experiments when the water mist was discharged into oil at a relatively moderate temperature (∼200 °C). In this paper, the mechanisms of cooling of hot oil by water mist are investigated, and the formation and development of the boiling layer during cooling are analyzed both experimentally and theoretically.

Experimental studies on interaction of water mist with class K fires

Interaction of water mist with cooking oil fires is studied experimentally and theoretically. A LDV/APV system is used to measure the velocity and diameter of water mist at different pressures in the experiments, and the effect of water mist velocity and diameter on fire extinguishment efficiency is investigated. The experimental results show that water mist has excellent surface cooling effect; it can control and extinguish cooking oil fires quickly without re-ignition. The critical temperature (Τfo) is calculated by energy balance equation, and the fire plume momentum is calculated and compared with that of water mist in order to determine the critical velocity (νwy) of fire extinguishment. This paper provides references for cooking oil fires extinguishment with water mist.

Characteristics of large cooking oil pool fires and their extinguishment by water mist

Large cooking oil pool fires, occurring in industrial oil cookers, present a severe hazard to food processing plants due to their size and the large amount of hot oil involved. This paper reports a series of full-scale fire experiments conducted in a large industrial oil cooker mock-up. The characteristics of large cooking oil pool fires and the effect of oil depth and hood position in the oil cooker on fire growth were studied. The use of water mist for extinguishing large oil pool fires and their extinguishing performance under different discharge pressure and with different types of water mist systems were investigated. Experimental results showed that the cooking oil underwent a substantial expansion in volume during heating. The fires developed quickly once the oil auto-ignited. The fire growth rate was affected by the oil depth in the pan and the hood position in the oil cooker. The water mist fire suppression systems effectively extinguished large cooking oil fires and prevented them from re-igniting. Their extinguishing performance was determined by the type of water mist system, discharge pressure and hood position in the oil cooker.

Application Of Water Mist To Extinguish Large Oil Pool Fires For Industrial Oil Cooker Protection

Large oil fires occurring in industrial oil cookers are very challenging to extinguish due to their size and the large amount of hot oil involved. This paper reports a study to use water mist for large industrial oil cooker protection. The extinguishing mechanisms of water mist and corresponding criteria required for extinguishing large pool cooking oil fires were investigated both theoretically and experimentally. Based on the extinguishing mechanisms and required criteria, two water mist systems were developed in the present work. A series of full-scale fire tests were conducted in a large industrial oil cooker mock-up. The study showed that the two water mist systems presently developed worked effectively to extinguish large cooking oil fires and prevented them from re-igniting. Their extinguishing performance was determined by the type of water mist system, discharge pressure and hood position in the oil cooker.

Extinguishment of Cooking Oil Fires by Water Mist Fire Suppression Systems

A series of full-scale experiments were conducted in a mock-up commercial cooking area to study extinguishing mechanisms and effectiveness of water mist against cooking oil fires. The impact of water mist characteristics, such as spray angle, droplet size, flow rate, discharge pressure and type of nozzle, on the effectiveness of water mist against cooking oil fires was investigated. A series of oil splash experiments were also conducted to determine if the oil was splashed by water mist. In addition, the change in oil composition during heating and fire suppression was determined using Fourier Transform Infrared (FTIR) technique. The study showed that cooking oil fires were very difficult to extinguish, because they burned at high temperature and re-ignited easily due to changes in oil composition during heating and fire suppression. The water mist systems developed in the present work effectively extinguished cooking oil fires and prevented them from re-ignition. The spray angle, discharge pressure, and water flow rate were important factors to determine the effectiveness of water mist in extinguishing cooking oil fires.

Experimental study of suppressing cooking oil fire with water mist using a cone calorimeter

Cooking oil fires in kitchens are difficult to extinguish as they are easy to re-ignite. Such kind of fires are different from the conventional flammable liquid fuel fires and have been classified into a new fire class, i.e. Class F, by some international recognized standard institutions such as National Fire Protection Association. Water mist fire suppression systems are proposed to suppress kitchen fires. In this paper, results in small-scale experiments using cone calorimeter on suppressing cooking oil fires with water mist will be reported. It is observed that good design of the system can suppress peanut oil fire effectively. There might be adverse effects on enhancing the combustion, producing more carbon monoxide and giving out more dark smoke for improper design.