Study for Fire Risk Assessment on a Mobile Phone Manufacturing Facility
|關鍵字:||風險評估;危害樹分析;Risk Assessment;HTA, Hazard Tree Assessment|
第一部份的評估結果發現，錫爐作業更換松香液體外洩造成火災與Burn-in Room高溫作業可能導致火災之發生，危害最為嚴重，應重新審核其標準作業操作程序之有效性及加強其改善預防措施。第二部份的研究顯示，高火災風險製程單元主要集中於使用易燃性化學品之機台（如錫爐製程區），而高火災風險區域則與高單價元件儲存區與成品儲存區有關。第三部份的分析發現，如增設排煙與灑水等防護設施，其火災危害相對其他較低；單獨設置排煙系統對於煙濃度控制最佳，但對溫度的影響有限；若增設撒水系統對於火場溫度具有控制(Fire Control)的效能，但是抑制(Suppression)效能並未顯現；另外亦發現火場主要危害為煙流危害效應。第四部份的分析顯示，對於大空間低人員密度區域，其人員避難快速，只有在靠近結點處方有累積現象產生，但相較於高密度人員區域，樓梯前與樓梯間則產生擁塞現象。此外，倘若將結果與廠內緊急應變紀錄相比對可以發現，若員工受過消防緊急應變避難逃生演練，其所花費之反應時間將較電腦模擬出之時間為短。
This research evaluates effectiveness and reliability of fire extinguishing systems by using renovating technological methods of risk assessment at a mobile phone manufacturing facility. The emphases of this study are focused on four stages. First, hazard tree analysis and RAMS are applied in the risk assessments of all tasks to evaluate the high-risk ones at this facility. Secondly, we use fire risk analysis techniques from insurance companies to identify the process units and areas with high risk potentials. Then, a fire simulation is carried out by using a field model, Fire Dynamics Simulator (FDS), developed by National Institute of Standards and Technology (NIST), to obtain the hazardous characteristics, such as temperatures, smoke generation rates, oxygen and carbon dioxide concentrations in the neighborhoods of process units and areas with highly potential risks. The last one is to apply the evaluation model, Simulex, developed by Integrated Environmental Solutions (IES), to analyze the employees’ evacuation time subjected to the dangerous conditions given by the previous stages. Finally, we can integrate the whole results of risk analyses to understand the fire risk in this mobile phone manufacturing facility. The results of part one show that the tasks of solder machines and burn-in rooms have the highest risks to cause the fire occurrences. Their procedure standards should be re-evaluated to avoid the fire situation. In the second part, it can be found that the process units, which use the flammable liquids, appear to have the greatest fire risk. At the areas with similar high risks, the hazardous levels are closely related with the numbers of workers, the frequency of operation and high-value equipment. Besides, the areas equipped with desmoke and automatic sprinkler systems have the relatively lower fire risk comparing with those without these systems. Establishment of desmoke systems is the best way to control smoke generation rate, but it has limited effect on temperature in fire fields. The automatic sprinkler system can enhance the control of fire, but it is not effective on fire suppression. The analysis of the last stage indicates that the less employee population in vast space, the better performances of evacuation, except some minor crowded movements occurred at the doors. However, the response time of employees, who had emergency response training before, would be shorter than the estimated time from computer system. Summarizing the results of the above-mentioned analyses under hazardous condition, this research can evaluate the effectiveness and reliability of fire protection system by using the quantitative models instead of the qualitative ones. Practices and emergency response training would lead to reduction of response time, and they can improve the overall safety level of the whole facility to avoid the losses of employees. Consequently, the control of fire incident would be improved.
|Appears in Collections:||Thesis|