참깻묵의 자연발화온도와 활성화 에너지를 통한 화재 및 폭발의 위험성 평가에 관한 연구

Abstract

In order to determine the risk of spontaneous ignition of sesame seed oil cake, the spontaneous ignition temperature according to the thickness of the sample container was measured, and through the critical ignition temperature, the apparent activation energy was calculated. In addition, to identify the physical characteristics of sesame seed oil cake, the thermal ignition characteristics of TG-DTA were analyzed, which led to the following conclusions. (1) The thermogravimetric measurement of sesame seed oil cake showed that the mass was reduced by 0.301 mg when the temperature increased from 27.86 ℃ to 201.50 ℃, and it was reduced by 10.676 mg when the temperature changed from 201.50 ℃ to 429.00 ℃. In addition, from 429.50 ℃ to 900.10 ℃, the mass was reduced by 6.194 mg. (2) The differential thermal analysis of sesame seed oil cake showed that 5.35 J of heat was generated at the first exothermic peak of 373.55～475.65 ℃, and 1.79 J was generated at the second exothermic peak of 512.91～580.61 ℃. (3) When the thickness of the sample container was 3 cm, the spontaneous ignition temperature of sesame seed oil cake was 180 ℃, and the non-ignition temperature was 175 ℃. The critical ignition temperature, which is the mean of the ignition temperature and non-ignition temperature, was 177.5 ℃. (4) When the thickness of the sample container was 5 cm, the spontaneous ignition temperature of sesame seed oil cake was 160 ℃, and the non-ignition temperature was 155 ℃. The critical ignition temperature, which is the mean of the ignition temperature and non-ignition temperature, was 157.5 ℃. (5) When the thickness of the sample container was 7 cm, the spontaneous ignition temperature of sesame seed oil cake was 145 ℃, and the non-ignition temperature was 140 ℃. The critical ignition temperature, which is the mean of the ignition temperature and non-ignition temperature, was 142.5 ℃. (6) When the thickness of the sample container was 14 cm, the spontaneous ignition temperature of sesame seed oil cake was 130 ℃, and the non-ignition temperature was 125 ℃. The critical ignition temperature, which is the mean of the ignition temperature and non-ignition temperature, was 127.5 ℃. (7) In order to predict the spontaneous ignition temperature according to the capacity of the sample container, the critical ignition temperature could be predicted at approximately 42 ℃ when the diameter of the container was 1 m. (8) When the thickness of the sample container was 3 cm, the time to reach the maximum temperature of 242 ℃ was 3 hours 6 minutes, and when the thickness was 5 cm, it took 10 hours 54 minutes to reach the maximum temperature of 280 ℃. In addition, when the thickness of the sample container was 7 cm, it took 19 hours 23 minutes to reach the maximum temperature of 312 ℃ while it took 49 hours 23 minutes to reach the maximum temperature of 394 ℃ when the thickness was 14 cm. The reason that it took longer to reach the maximum temperature when the container was thicker was because the heat transfer from the surface of the container to the center was more difficult. (9) The ignition delay time according to the thickness of the container was 2 hours 24 minutes when the thickness was 3 cm and 8 hours 48 minutes when it was 5 cm. In addition, when the thickness was 7 cm, the ignition delay time was 10 hours 30 minutes and when the thickness was 14 cm, it was 13 hours 30 minutes. The reason that the ignition delay time was longer when the container was thicker was also because the heat transfer from the surface of the container to the center was more difficult. (10) The apparent activation energy of sesame seed oil cake was calculated using the Frank-Kamenetskii parameters and the critical ignition temperature, and 97.10 kJ/mol was obtained.