Page 481 - Dust Explosions in the Process Industries

448 Dust Explosions in the Process Industries

Figure 6.1 6 Maximum explosion pressure Pred
measuredin dust exdosions in an industrial 6.7 m3
0 Lbag filter unit in normal operation, P,,,, = 0.1
0 100 200 bar&). (data from Lunn and Cairns, 1985).
Comparison with VDI 3673 (7979 edition) (From
Kst FROM 20 L SPHERE [bar.m/sl Eckhoff, 1990).

0
CLEAN AIR
OUTLET
SIX VENT
OPENINGS -
OF 0.23 m2
EACH 30 FILTER BAGS
ON PERFORATED
SUPPORTS

TWO VENT
OPENINGS
OF 0.34 m2

Figure 6.17 A 5.8 m3 experimental bag filter in Norway (From Eckhoff et a/., 1989).

6.2.5.2
Vented Explosions in a 5.8 m3 Bag Filter in Norway

These experiments were reported in detail by Eckhoff, Alfert, and Fuhre (1989). A per-
spective drawing of the experimental filter is shown in Figure 6.17 and a photograph of
a vented maize starch explosion in the filter in Figure 6.18.
Dust explosions were initiated in the filter during normal operation. A practical worst-
case situation was realized by blowing dust suspensions of the most explosible concen-
tration into the filter at 35 m/s and igniting the cloud in the filter during injection. Four