Environmental Engineering Reference
In-Depth Information
Fig. 2.3 The relation plots of combustion speed of H
2
O
2
-azidoethane mixture and the pressure. 1
H
2
O
2
-azidoethane; 2 N
2
O
4
-unsym-dimethylhydrazine; 3 Mercury fulminate; 4 Nitroglycerine; 5
hexogen
the reaction. The combustion of this explosive is much faster than the above two
kinds of explosives. The burning rate is a function of pressure.
u ¼ a
þ
bP
v
The index v is about 0.5. Figure
2.3
indicates the relation between combustion
speed of H
2
O
2
-azidoethane mixture and the pressure.
The burning rate is less affected by pressure if the pressure is 20
40 atm.
Probably, the reason is that the main stage of burning reacts in the condensed phase
and the burning rate is controlled by the reaction in the condensed phase. This kind
of explosive usually have large burning rates and high melting points.
-
2.2.1.5 Burning Stability of Liquid Explosives
The vortex of the liquids brings a disturbance for the
fl
flame front and results the
deformation of
flame front. So the burning stability of liquid explosives is broken.
The deformation and disturbance increase gradually, and makes the burning rate
lower,
fl
finally leads to the detonation. Stable burning reaches only when the mass
burning rate is within certain ranges.
The gravity, surface tension, and viscosity of the liquids help to hinder the
deformation of
flame fronts. After calculating the stability impaction of gravity and
surface tension, the normal burning limit rate is guaranteed if the below condition is
met.
fl
1
=
4
u
m
¼
ð
4
a
k
g
q
1
d
1
Þ
ð
2
:
19
Þ
