The Study of Pressures and Non-transmission Properties during Internal Ignitions in the Flameproof Enclosures of Various Volumetric Parameters

• Main Authors: HONG, JYUN-TING, 洪均廷
• Other Authors: SHU, YI-LIANG
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/m44332

碩士 === 中臺科技大學 === 環境與安全衛生工程系碩士班 === 103 === Since the period of Industrial Revolution, accidents such fires and explosions have frequently occurred in the workplace of coal mining fields due to the lack of adequate explosion protection measures. The basic demand for explosion protection was therefore initiated from the need of lighting simple tools. Currently the demand for explosion protection has widened to any industries that explosive atmosphere may exist, and the implementation of explosion protection safety becomes much more important. To strengthen the occupational safety in Taiwan, the government authorities employ mandatory type verification approval scheme for luminaires, rotating machines and switch boxes intended for use in hazardous areas from 2012. With promulgation of the policies, domestic users increased of use of explosion protected equipment while driving manufacturers to put more efforts to the research and development of Ex equipment. Flameproof enclosures are typical of providing the ability to withstand pressure and the avoidance of flame transmission from the enclosure to the external explosive atmosphere. This study compares the pressures during internal ignition measured from different enclosure volumes and different dimensional ratios. The results from the experiments shows that larger-volume enclosure produced higher pressures, and narrow-long enclosure also produce higher pressures during internal ignition. This study also investigate the safe gap of flanged joints from enclosures with different volume and dimensional ratios. The results also show that narrow-long enclosure exhibits higher risk of flame transmission occurrence at the same joint gap. The results from this study implies that design and use of narrow-long flameproof enclosures should be avoided in terms of safety requirement. This study gives valuable reference and findings for the design of flameproof equipment and also helpful guidance for selection of representative test samples and conformity assessment during certification work.