Page 530 - APPLIED PROCESS DESIGN FOR CHEMICAL AND PETROCHEMICAL PLANTS, Volume 1, 3rd Edition

496 Applied Process Design for Chemical and Petrochemical Plants

CONCENTRATION OF ETHYL ALCOHOL IN LIQUID PHASE, wt% CONCENll\ATION OF WATER, llol %
0 10 20 30 40 60 80 70 80 90 100 80 70 80 60 40 311 20 10
70
9

eo

c,1 (9.MII
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..; ..;
a: 110 a:
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�
.. - �
)( �
:i IGO :i
u. u.
0 0
!z IO !z
� �
! IO i
LfL (JAi u.
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JO

10
1

0
0 10 20 30 40 60 80 70 BO 90 100 20 311 40 60 80 � IO 80 lGO
CONCENTRATION OF ETHYL ALCOHOL IN LIQUID PHASE, vol % CONCENTRATION OF ETHYL ALCOHOL, VOi %
Figure 7-52A. Vapor-liquid data for solutions of ethyl alcohol relating Figure 7-528. Flashpoints of ethyl alcohol-water mixtures as a func-
to mixture flashpoints. By permission, Hercules, Inc. tion of liquid phase concentration at one atmosphere total pressure.
By permission, Hercules, Inc.

Aqueous Solutions of Flammable Liquids tern. In a containment vessel, the peak pressure from a
detonation beginning at atmospheric pressure may rise to
Some organic compounds can be in solution with about 19.7 times or 289.8 psia. Figure 7-53 illustrates det-
water and the mixture may still be a flammable mixture. onation velocities and pressures. Barker, et. al [87] discuss
The vapors above these mixtures such as ethanol, blast loaded structures.
methanol, or acetone can form flammable mixtures with Table 7-23 presents U.S. Atomic Energy Commission
air. Bodurtha [39] and Albaugh and Pratt [ 47] discuss the data [ 43], which expresses the overpressure above normal
use of Raoult's law (activity coefficients) in evaluating the required to do the damage indicated. Table 7-24 presents
effects. Figures 7-52A and B illustrate the vapor-liquid a collection of industrial overpressure damage situations
data for ethyl alcohol and the flash point of various con- [53]. The overprcssuring (P - P 0) is expressed [43]:
centrations, the shaded area of flammability limits, and
the UEL. Note that some of the plots are calculated and (P - P 0) = P [2k/(k - l)] lv/v, - I] (7-56)
0
bear experimental data verification.
k = ratio of specific heats
Blast Pressures v, = velocity of sound in the medium through which
the shock wave travels, ft/sec
Deflagrations and detonations produce pressures asso- v = shock velocity (from test data or specific calcula-
ciated with the resulting shock/pressure waves. These tions), ft/ sec
pressures can be sufficiently large to damage and/or P,' = P O = initial pressure of system, psia
demolish enclosed vessels, equipment, and buildings. A P max = P = peak pressure of blast, psi a
deflagration can produce pressure rises in excess of 8:1
and rises of 40:1 when a reflected wave develops from a Other references on the subject of blast damage are
detonation, referenced to the initial pressure of the sys- [ 48] [ 49] [50]. Tables 7-25A and 7-258 provide several