Page 385 - Dust Explosions in the Process Industries

354 Dust Explosions in the Process Industries

-
V?
to=t INITIAL LAMINAR FLAME EXPLOSION TUBE
--3
INITIAL WEAK COMPRESSION WAVE
"' FOLDED FLAME

VF
TURBULENCE EDDIES
I

FLAME
TURBULENCE

TURBULENT FLAME

TURBULENT FLAME

HIGHLY TURBULENT FLAME

COMBUSTION f-- RETONATION
PRODUCTS WAVE
ROTATI ORAL DETONATION
WAVE FRONT
\ \
COMBUSTION -c- \
PRODUCTS
COMBUSTION PRODUCTS
I PLANE AT WHICH IGNITION
1 COMPRESSION OR SHOCK WAVE '
BY SHOCK WAVES WOULD HAVE
I TAKEN PLACE IN THE ABSENCE
' OF OTHER FLAME
SERIES OF CONSECUTIVE
COMPRESSION WAVES
Figure 4.63 Characteristic phenomena during acceleration of gas or dust flames in one-end-open
long tubes, from laminar combustion via turbulent combustion to detonation. V, is the flame speed;
V2 is the velocity of the unburned gas or dust cloud ahead of the flame (From lost and Wagner, in
Freytag, 7 965).