Application Of Water Sprays To Industrial Oil Cooker Fire

Abstract

Fourteen full-scale fire tests were conducted to determine the optimal design parameters of water-based protection systems against large industrial oil cooker fires. All but one test fires were self-ignited by heating the oil inside a test pan above its auto-ignition temperature. Three test mock-ups that simulated industrial oil cookers were fabricated for the tests: 3.0 m long by 2.4 m wide, 6.1 m long by 2.4 m wide, and 12.2 m long by 2.4 m wide. Three types of water spray systems utilizing 13 mm orifice sprinklers, 13 mm orifice spray nozzles, and 6.4 mm orifice spray nozzles, respectively, were installed to discharge water with various discharge densities into burning oil inside a pan. Rapid fire suppression was achieved, although fire flare-up was very pronounced and the interaction between the fire and the water spray was very intense. Test results showed that the systems using the nominal 6.4 mm orifice spray nozzles placed in a double-row 0.76 m above the oil surface, discharging a 20 mm/min density, yielded the best performance. The tests also indicated that bronze sprinklers or bronze spray nozzles may not be strong enough to use against auto-ignition fires inside a cooker. None of the stainless steel sprinklers or spray nozzles showed any damage after they were exposed to several test fires.

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

“…Other changes in the oil properties included an increase in the specific heat or heat capacity, and a decrease in its viscosity. The specific heat of canola oil, C p , at room temperature is 1.91 kJ/kg.K, but its average value at the temperature range of 20 o C to 160 o C increases to 2.5 kJ/kg.K [24]. The bulk of the oil auto-ignited at 343 o C~362 o C in the experiments.…”

“…Nam [24] conducted a series of full-scale fire tests in which water spray was used to suppress large cooking oil fires associated with large industrial oil cookers. Test results showed that water spray was capable of extinguishing large oil fires and no vapour explosion was observed during suppression.…”

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

“…5 and 6. Based on the known properties of other cooking oils and hydrocarbon fuels [2,12,13], the heat of combustion and the burning rate of canola oil are given as 39,200 kJ/kg and 0.0462 kg/m 2 s. The heat of gasification of canola oil is assumed to be 970 kJ/kg, the same value as ethyl alcohol in consideration of their similar burning rate (0.04 kg/ m 2 s) [13]. The fraction of heat of combustion of the oil that is transferred from the flame to the fuel is assumed to be 0.1 in consideration of fine water drops and their vapors in the flame.…”

“…The feasibility of using sprinkler water sprays for industrial oil cooker protection has been previously studied [2]. A series of full-scale fire tests were conducted in an outdoor facility involving three large industrial oil cooker mock-ups.…”

“…They are typically conveyorized fryers, or occasional batch kettles. Industrial oil cookers contain cooking oil, varying from a few hundred liters to tens of thousands of liters, and their cooking surfaces vary from 4.6 m 2 (50 ft 2 ) to several hundred square feet [1,2].…”