Discharge Characteristics of Cryogenic Fluids From a Pressurized Vessel.
Discharge Characteristics of Cryogenic Fluids From a
Pressurized Vessel.
(458 K)
Yang, J. C.; Pitts, W. M.; Breuel, B. D.; Gmurczyk, G.
W.; Rinkinen, W. J.; Cleveland, W. G.
Paper XIII-6;
Institute for Liquid Atomization and Spary Systems
(ILASS-Europe) and CORIA. Liquid Atomization and Spray
Systems, 6th International Conference Proceedings.
ICLASS 94. July 18-22, 1994, Rouen, France, Begell
House, Inc., NY, Yule, A. J.; Dumouchel, C.,
Editor(s)(s), 1047-1054 pp, 1994.
Keywords:
cryogenic fluids; discharge rate; halon 1301
Abstract:
An experimental technique to study the rapid release of
liquid cryogenic fluids from a pressurized vessel
orientated downward is described. A rupture disc was
used as the release mechanism. Experimental
observations were made on the discharge characteristics
of two cryogenic fluids, C4F10 (FC-31-10) and C3F8
(FC-218), which were proposed as potential candidates
for replacement of halon 1301 (CF3Br) as fire
suppressant. For comparison, halon 1301 was also
included in this study. Various parameters that could
influence the discharge process were studied. These
parameters were: (1) orifice opening, (2) the effect of
an extension tube at the vessel exit, and (3) initial
charge pressure. The events occurring internal and
external to the vessel during discharge of FC-31-10 or
FC-218 were studied with high-speed photography and a
transparent acrylic vessel. The average penetration
velocities of the spray at various locations downstream
were measured by means of a laser extinction technique.
Two distinct flashing behaviors were observed at the
vessel exit. The first flashing occurred immediately
after the bursting of the rupture disc, and the second
appeared at or before the moment the liquid was depleted
from the vessel. During depressurization, no internal
boiling of FC-31-10 or FC-218 was observed. Increasing
the initial charge pressure reduced the emptying time of
the liquid. Decreasing the orifice opening was found to
increase the liquid emptying time significantly. The
behavior of the liquid inside the vessel was found to be
very similar whether an extension tube was present or
absent at the vessel exit: an indication of two-phase
critical flow.