Potential explosion hazard of polyester resin dust formed from a granulation process: Limiting oxygen concentration with different pressures

When polyester resin (PR) is manufactured on an industrial scale, the spreading of the dust cloud is a potential explosion hazard. The maximum explosion pressure and maximum rate of pressure rise were in the range 3.6 bar < P-max(500) < 9.8 bar and 32 < (dP dt(-1))(max)(500) < 356 bars(-1), respectively, which is more than that of sugar dust explosion. The explosion index K-st = V-1/3(dP dt(-1))(max) was in the range 8.86 bar m s(-1) < K-st(500) < 96.63 bar m s(-1), which belongs to dust explosion class St-1. In addition, the results indicated that the explosion pressure can be significantly lessened with lower LOC. However, the inhibiting effect is not obvious at higher initial pressure. Therefore, the oxygen concentration must be considered as low as feasibly possible at a higher pressure to lessen the explosion hazards in production as well as handling process. Moreover, according to rough set analysis, the most significant factors for explosion intensity (P-max) are dust concentration and initial pressure. The two parameters should be prudently controlled during the storage, transportation, and manufacturing of PR dust.