Dynamic response and effect of apertures on explosion parameters of flameproof apparatus

• Cylindrical flameproof enclosures with apertures (gap/slit in cover and breathing element on wall) are investigated.
• Effect of interconnecting tube of different diameters between two identical enclosures are also investigated.
• Explosion parameters are decreased for enclosures with apertures (gap or porosity).
• Interconnection results in high Pmax in secondary enclosure, and which is more for Ø 1.2 cm tube than that for Ø 0.3 cm tube.
• However, (dp/dt)ex is considerably increased in secondary enclosure for Ø 0.3 cm tube than that for Ø 1.2 cm tube.

Explosion parameters for closed flameproof apparatus are changed when apertures like gap (e.g. push button) and porous structures (breathing element) are introduced on the cover or wall of the flameproof enclosures. Similarly, an interconnecting tube between two enclosures, results in significant change in explosion parameters. It is observed that the maximum explosion pressure, maximum rate of pressure rise and severity index are higher for enclosures with apertures on cover or body than that of enclosures without apertures. In case of two interconnected identical enclosures, the explosion parameters are increased in the secondary enclosure and higher than that of primary enclosure and also of isolated enclosure.