화학공학소재연구정보센터
Korean Chemical Engineering Research, Vol.61, No.1, 80-88, February, 2023
저밀도 폴리에틸렌 분진의 폭발특성 분석
Explosion Characteristics Analysis of Low-Density Polyethylene Dust
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초록
저밀도 폴리에틸렌(Low-density polyethylene, LDPE)은 분진폭발 관련 특성치에 대한 기준이 제시되고 있지 않아 제조 및 취급설비의 안전한 설계가 어렵다. 이 연구에서는 LDPE 제조공정 중 Bag Filter에서 채취한 분진(LDPE 1)과 Silo 등의 설비 외부에 누설된 퇴적 분진(LDPE 2)에서 채취한 2개 시료에 대하여 분진폭발 시험을 수행하였고 그 중 LDPE 2 분진에 대하여 요약하였다. 입도분석 결과, 체적기준 평균입경은 95.04 μm, 수밀도는 0~1 μm로 나타났다. 최 대폭발압력(Pmax)은 6.6 bar, 최대폭발압력상승속도는 1500 g/m3에서 366 [bar/s]로 분진폭발지수(Kst)는 99.4 bar·m/s로 ST-1 등급임을 확인하였다. 또한, 최소점화에너지는 10 mJ이며 최소점화온도는 450℃로 나타났다. 현재, 제조 및 취 급 설계는 고밀도 폴리에틸렌(HDPE)의 특성값을 기초로 한다. 그러나, 시험 결과 LDPE 2 분진이 HDPE(입자지름 61.6 μm)보다 위험성이 높은 것으로 나타나 LDPE 제조공정에서 HDPE 설계기준을 적용할 때는 주의가 필요하다.
Ensuring safety in the designing of manufacturing and handling facilities for low-density polyethylene (LDPE) is difficult because there are no standards for the dust explosion characteristics of LDPE. In this study, a dust explosion test was performed on two dust samples collected from a bag filter (LDPE 1) during the LDPE manufacturing process and sedimentary dust (LDPE 2) leaked outside a facility such as a silo, and the LDPE 2 explosion test results were summarized. Particle size analysis showed that the volume-based particle diameter (median) was 95.04 μm and the number density was 0-1 μm. The maximum explosion pressure (Pmax) was 6.6 bar, and the maximum rate of explosion pressure rise was 366 [bar/s] at 1500 g/m3. Accordingly, the dust explosion index (Kst) was 99.4 bar·m/s, which was confirmed as ST-1 grade. Moreover, the minimum ignition energy and minimum ignition temperature was 10 mJ and 450℃, respectively. Currently, manufacturing and handling design is based on the characteristic values of high-density polyethylene (HDPE). However, as the test results show that LDPE 2 dust has a higher risk than HDPE (particle diameter 61.6 μm), caution is required when using the HDPE design criteria in the LDPE manufacturing process.
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