Dispersed liquid agent fire suppression screen apparatus

Yang, Jiann C.; Donnelly, Michael; Privé, Nikki C.; Grosshandler, William L.

doi:10.6028/nist.ir.6319

Cited by 9 publications

(11 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The aerosol injection system described earlier was used by Pitts et al [26] to compare the suppression performance of a water mist and methoxynonafluorobutane in the TARPF to that measured in the steadystate Tsuji burner [16]. The air flow in the tunnel was fixed at 6.67 x 10 -3 m 3 /s and the porous burner was operated at a propane flow rate of 33 mL/s.…”

Section: Aerosol Agentsmentioning

confidence: 99%

“…In the Tsuji burner experiments, Yang et al [16] used a droplet delivery system that assured efficient transport of fine liquid droplets to the flame. They found that a calculated water mist mass fraction of 0.03 in the air stream was sufficient to extinguish their laminar counter-flow flame.…”

Section: Aerosol Agentsmentioning

confidence: 99%

“…Yang et al [16,1999] developed a means to accurately meter alternative liquid agents using a nebulizer, but their screening device operated in a continuous rather than impulsive mode. Commercial fuel injectors were considered but the flow rates and injection duration were not adjustable over the range and with the precision necessary for the current application.…”

Section: Aerosol Agent Controlmentioning

confidence: 99%

See 2 more Smart Citations

Transient application, recirculating pool fire, agent effectiveness screen:

Grosshandler¹,

Hamins²,

McGrattan³

et al. 2001

Self Cite

View full text Add to dashboard Cite

NISTIR 6733ii EXECUTIVE SUMMARY * Because of its many positive attributes, halon 1301, or trifluorobromomethane (CF 3 Br), has been used as a fire extinguishing agent in many applications including aircraft, ships, and specialized structures. Due to its high ozone depletion potential, however, world-wide production was halted in 1994. In the search for a long-range replacement, novel types of extinguishing agents and delivery mechanisms are under development. To gauge the suitability of a replacement agent, methods are needed to evaluate the material's suppression effectiveness under conditions that relate to field applications.In this study, a laboratory-scale facility has been developed to screen the suppression effectiveness of agents that are delivered in a transient fashion such as solid propellant gas generators. The transient application, recirculating pool fire (TARPF) agent effectiveness screen features a propane fire stabilized behind an obstruction, which is known to be a highly challenging suppression configuration. The character of the flame and the impact of the air flow, fuel flow, obstruction geometry, and rate of agent addition on the amount of material needed for suppression are evaluated for N 2 , CF 3 Br, and a solid propellant gas generator (SPGG). The importance of the injection process on the flow field and the transport of the agent downstream is examined, and a simple mixing model is used to explain the observed trend of decreasing suppressant mole fraction with increasing injection duration, even for agents as different as CF 3 Br and N 2 . Direct numerical simulation of the suppression event is shown to successfully predict the quantity and rate of N 2 required to extinguish the flame based upon a published global reaction rate for premixed propane/air flame propagation. Important Findings:• The minimum mole fraction of agent for suppression, normalized by the cup burner value, correlates with [1 -exp(-∆ t/ τ )] -1 , where ∆ t is the injection time interval and τ characterizes the mixing time behind the obstacle in the flow.• The general character of the flame and its extinction by a thermal gaseous agent is captured by a direct numerical simulation of the flow based upon single -step chemistry, and numerical experiments have corroborated the simple correlation of the experimental data for N 2 .• The measured difference between the decrease in agent storage bottle pressure and the arrival of the agent at the fire highlight the importance of determining the agent concentration locally and the difficulty in relating changes in bottle pressure to actual mixing conditions. • For the first time, both compressed and solid-propellant generated gases can be compared side by side, and the effect on performance of different formulations, particle loadings and burning rates for various SPGG designs can be unambiguously discriminated.• When the temperature of a hot surface downstream of the pool is above 800 o C, the flame, following suppression, will reignite and stabilize on the hot surface. At ...

show abstract

Section: Aerosol Agentsmentioning

confidence: 99%

Section: Aerosol Agentsmentioning

confidence: 99%

Section: Aerosol Agent Controlmentioning

confidence: 99%

See 1 more Smart Citation

Transient application, recirculating pool fire, agent effectiveness screen:

Grosshandler¹,

Hamins²,

McGrattan³

et al. 2001

Self Cite

View full text Add to dashboard Cite

show abstract

“…The liquid flow rate was varied from 0.3 ml/min to 1.2 ml/min. Unlike the piezoelectric droplet generator, the nebulizer creates droplets with a range of diameters, as evident in the PDPA measurements [3].…”

Section: An Aerometrics Two-component Phase Doppler Particle Analyzermentioning

confidence: 99%

“…Irrespective of the uncertainty associated with the estimated agent mass concentration, water and the aqueous agents studied here are found to be more effective than CF 3 Br, compared to the propane cup-burner value (17% by mass) for CF 3 Br [6]. The computational study by Lenta* and Chelliah [7] also demonstrates that 20-um water droplets are more effective (4.24% vs. 5.9% by mass) in extinguishing an opposed-flow methane diffusion flame than CF 3 Br at an extinction strain rate of ~ 176 sec" 1 .…”

Section: An Aerometrics Two-component Phase Doppler Particle Analyzermentioning

confidence: 99%

Recent Results from the Dispersed Liquid Agent Fire Suppressant Screen

Yang¹,

Privé²,

Donnelly³

et al. 1999

View full text Add to dashboard Cite

Public reporting burden lor this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden to

show abstract

Hysteresis and multi-state behavior of counterflow flame in a blowing cylindrical burner

Chai

2009

J. Therm. Sci.

View full text Add to dashboard Cite

This study focuses on flame hysteresis over a porous cylindrical burner. The hysteresis results from different operation procedure of the experiment. Gradually increasing inflow velocity can transform the envelope flame into a wake flame. The blow-off curve can be plotted by determining every critical inflow velocity that makes an envelope flame become a wake flame at different fuel-ejection velocities. In contrast, decreasing the inflow velocity can transform the wake or lift-off flame into an envelope one. The reattachment curve can be obtained by the same method to explore the blow-off curve, but the intake process is reverse. However, these two curves are not coincident, except the origin. The discrepancy between them is termed as hysteresis, and it results from the difference between the burning velocities associated with both curves. At the lowest fuel-ejection velocity, no hysteresis exists between both curves owing to nearly no burning velocity difference there. Then, raising the fuel-ejection velocity enhances hysteresis and the discrepancy between the two curves. However, as fuel-ejection velocity exceeds a critical value, the intensity of hysteresis almost keeps constant and causes the two curves to be parallel to each other.

show abstract

Dispersed liquid agent fire suppression screen apparatus

Cited by 9 publications

References 8 publications

Transient application, recirculating pool fire, agent effectiveness screen:

Transient application, recirculating pool fire, agent effectiveness screen:

Recent Results from the Dispersed Liquid Agent Fire Suppressant Screen

Hysteresis and multi-state behavior of counterflow flame in a blowing cylindrical burner

Contact Info

Product

Resources

About