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Simulation of Dry Bay Discharge of Alternative Agents



Jiann C. Yang, Thomas G. Cleary, William L. Grosshandler


As a continuation of the USAF/Navy/Amy/FAA sponsored halon replacement project, the discharge characteristics of the three selected akernative agents (CFJ, FC-218. and HFC- 125) for dry bay applications will be further evaluated. Halon 1301 will also be included in the study for the purpose of comparison. The experimental set-up involves a pressure vessel in which a fixed amount of agent is placed. The vessel is pressurized with nitrogen to a specified charge pressure. To simulate dry bay applications, discharge of the agent from the vessel into an unconfined space is initiated by a quick-action solenoid valve or a squib. The shape of the vessel is either cylindrical or spherical. To monitor the behavior of the agent inside the vessel during discharge, internal pressure and temperature changes are measured. A cylindrical pressure vessel with sight glasses is used for visual observations of the internal processes during discharge. The external behavior of the discharge is evaluated using a laser-light attenuation technique which has been used in the previous agent screening project and high speed photography. Parameters to be studied include: (1) nitrogen charge pressure, (2) initial amount of agent, (3) discharge temperature, (4) discharge orientation, and (5) discharge orifice size. Since the work is still in progress, only the data from FC-218 discharges will be presented. The results were obtained using a cylindrical vessel (with sight glasses and equipped with a Marotta valve) at room temperature and 213 fill (by volume) condition. Nitrogen charged pressures varied from about 2.75 to 4.12 MPa.


Yang, J. , Cleary, T. and Grosshandler, W. (1994), Simulation of Dry Bay Discharge of Alternative Agents, Other, National Institute of Standards and Technology, Gaithersburg, MD, [online], (Accessed July 23, 2024)


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Created January 1, 1994, Updated February 19, 2017