Page 122 - Dust Explosions in the Process Industries

Dust Explosions:An Overview 95
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LENGTH OF DUCT [ml
LENGTH OF VENT DUCT iml
Figure 1 .lo8 The influence of the length
of a straight vent duct of internal diameter
130 mm on the maximum pressure during Figure 1 .I 09 The influence of the length of a
explosions of three different dusts in air in a straight vent duct of internal diameter 0.35 m on
20 liter spherical vessel with vent cover of the maximum dust explosion pressure in a 7 m3
diameter 130 mm and bursting strength 0.1 vessel vented into the duct via a 0.35 m diam-
bar(g) between vessel and duct (From eter bursting disk of bursting pressure 0.47
Crowhurst, 19881. bar(@ (From TNO, 1979).

0.1 0.2 0.4 0.6 0.8 1.0 1.5 2.0
MAX. EXPLOSION PRESSURE IN VENTED VESSEL
WITHOUT VENT DUCT [bar (gll

Figure 1.1 10 Maximum pressure in a vented vessel with a vent duct as a function of maximum explo-
sion pressure without a duct, for various duct lengths. The diameter of the duct equals the diameter
of the vent. There are no sharp bends (From Walker, 1982).