Experimental Study of Water Sprays for the Attenuation of Fire Thermal Radiation

2000 ◽  
Vol 123 (3) ◽  
pp. 534-543 ◽  
Author(s):  
S. Dembele ◽  
J. X. Wen ◽  
J.-F. Sacadura

A laboratory experimental work is carried out to investigate the attenuation ability of water sprays subjected to thermal radiation. The objective is to analyze the key parameters involved in the mitigation properties of this fire protection technique. The spectral transmittances of two types of sprayers, TG03 and TG05, are measured with a Fourier infrared spectrometer under various conditions. The wavelength range varies from 1.5 to 12 μm. The influence on the transmittance of both the flow rate and the pressure ranging from 1 to 7 bars, as well as the effect of the number of spray nozzles are considered. The results clearly show the advantage of small drops with high concentration. An investigation on the multi-ramp curtain configuration also provides valuable information on the mitigation behavior of the whole spray. Key guidelines are provided for fire protection engineering.

2016 ◽  
Vol 78 (5-3) ◽  
Author(s):  
Duratul Ain Tholibon ◽  
Junaidah Ariffin ◽  
Jazuri Abdullah ◽  
Juliana Idrus

A large number of studies both theoretical and experimental have been devoted to understand the physical mechanisms underlying the bar formation. This can be investigated by carrying out an experimental work in an erodible sand bed channel using a large-scale physical river model. The study included the various hydraulic characteristics with steady flow rates and sediment supply. An experimental work consists of four matrices of flow rate and channel width with other variables namely grains size and bed slope were kept constant. Details of bar profile development that generated using Surfer, a software used for 3D elevation plots are included.


2014 ◽  
Vol 699 ◽  
pp. 915-920 ◽  
Author(s):  
Bukhari Manshoor ◽  
Mohd Fahmi Othman ◽  
Izzuddin Zaman ◽  
Zamani Ngali ◽  
Amir Khalid

The plant industry is required to measure flow rate more accurately to meet plant operation and cost accounting objectives. The opposing concern of improving flow meter accuracy is resolved by using flow conditioners. The distance of implementation of flow conditioner upstream of the orifice plate flowmeter is also need to be addressed. Hence, in present study, an analysis of the porosity of fractal flow conditioner towards orifice plate flowmeter’s accuracy and the best distance of fractal flow conditioner upstream of the orifice plate flowmeter was determined. In an experimental work, a different porosity of the fractal flow conditioners were installed with different distance upstream of the orifice plate in conjunction with the different disturbances to assess the effects of these devices on the measurement of the mass flow rate. Data gained for all the plates showed that there is increment of pressure drop and change in discharge coefficient of the orifice with lower β value of fractal flow conditioner. Good comparisons with the previous experimental work demonstrate the fractal flow conditioner can preserve the accuracy of metering up to the level required in the standards.


2016 ◽  
Vol 78 (8-3) ◽  
Author(s):  
Siti Zubaidah Sulaiman ◽  
Rafiziana Md Kasmani ◽  
A. Mustafa

Flame propagation in a closed pipe with diameter 0.1 m and 5.1 m long, as well as length to diameter ratio (L/D) of 51, was studied experimentally. Hydrogen/air, acetylene/air and methane/air with stoichiometric concentration were used to observe the trend of flame propagation throughout the pipe. Experimental work was carried out at operating condition: pressure 1 atm and temperature 273 K. Results showed that all fuels are having a consistent trend of flame propagation in one-half of the total pipe length in which the acceleration is due to the piston-like effect. Beyond the point, fuel reactivity and tulip phenomenon were considered to lead the flame being quenched and decrease the overpressures drastically. The maximum overpressure for all fuels are approximately 1.5, 7, 8.5 barg for methane, hydrogen, and acetylene indicating that acetylene explosion is more severe. 


Water ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 2189
Author(s):  
Tingchao Yu ◽  
Xiangqiu Zhang ◽  
Iran E. Lima Neto ◽  
Tuqiao Zhang ◽  
Yu Shao ◽  
...  

The traditional orifice discharge formula used to estimate the flow rate through a leak opening at a pipe wall often produces inaccurate results. This paper reports an original experimental study in which the influence of orifice-to-pipe diameter ratio on leakage flow rate was investigated for several internal/external flow conditions and orifice holes with different shapes. The results revealed that orifice-to-pipe diameter ratio (or pipe wall curvature) indeed influenced the leakage flow, with the discharge coefficient ( C d ) presenting a wide variation (0.60–0.85). As the orifice-to-pipe diameter ratio decreased, the values of C d systematically decreased from about 12% to 3%. Overall, the values of C d also decreased with β (ratio of pressure head differential at the orifice to wall thickness), as observed in previous studies. On the other hand, orifice shape, main pipe flow velocity, and external medium (water or air) all had a secondary effect on C d . The results obtained in the present study not only demonstrated that orifice-to-pipe diameter ratio affects the outflow, but also that real scale pipes may exhibit a relevant deviation of C d from the classical range (0.61–0.67) reported in the literature.


2019 ◽  
Vol 133 ◽  
pp. 893-900 ◽  
Author(s):  
Cheng-Long Wang ◽  
Jing-Hu Gong ◽  
Jia-Jie Yan ◽  
Yuan Zhou ◽  
Duo-Wang Fan

2014 ◽  
Vol 955-959 ◽  
pp. 1840-1849
Author(s):  
Cherng Shing Lin ◽  
Kuo Da Chou

Taiwan is an island nation with numerous mountains and few plains. Consequently, the number of tunnel projects has gradually increased and tunnels are becoming longer. Because the number of large tunnels that exceed 1000 meters in length has increased, the effective escape and evacuation of people during a fire and the minimization of injury are crucial to fire protection engineers. For this study, an actual example of a fire that occurred in Hsuehshan Tunnel (12.9 kilometers and the longest tunnel in Southeast Asia) was used. A fire dynamics simulator (FDS) including numerical simulation software was applied to analyze this fire and the relevant information that was collected was compared and verified. The fire site simulation showed the escape and evacuation of people during the fire. Simulations of the original fire site and the possible escape time for people with various attributes were discussed to provide quantitative data and recommendations based on the analysis results, which can serve as a reference for fire protection engineering.


2014 ◽  
Vol 522-524 ◽  
pp. 396-400 ◽  
Author(s):  
Wei Feng Zhang ◽  
Jian Hui Shu

The experimental study on the mechanism of CO2 absorption and desorption was tested by two kinds of glycinate (SG and PG) with TEA. The absorption and regeneration of CO2 by mixed absorption liquid were tested and compared with each other. The results showed that a low concentration of TEA in the SG and PG increased CO2 absorption capacity of mixed absorption solution. Addin more TEA on PG or SG lowered CO2 absorption capacity of mixed absorption solution. Desorption of PG didnt change with TEA. The low concentration of TEA had a role in promoting the desorption of mixed absorption solution (SG+TEA), and the high concentration of TEA inhibited the desorption of mixed absorption solution (SG+TEA).


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