scholarly journals Implementation of Low-Pressure Water Mist System for Fire Suppression inside a Model of Road Tunnel

Author(s):  
Hatem Sadek

Previous studies have proven the performance of certain water mist system in general or in suppressing certain tunnel fires. The southern tunnel under the Suez Canal in the province of Ismailia length of 4 kilometers and 800 meters is serving the movement from Ismailia to Sinai through the Suez Canal old and new, while serving the northern tunnel movement from Sinai to Ismailia through the two channels. This tunnel in Ismailia is the largest in the world, with outer diameter of 12.6 meters, the internal 11,40 meters, the length of the tunnel is 4830 meters and reaches 6830 meters with the entrances and exits, the distance between the north and south tunnels 12 meters, and the maximum depth of the tunnel 45 meters down both Suez Canals. Since completing this project in the begin of 2019, this Tunnel did not experimentally test. This paper describes an experimental study of a low-pressure water-mist system (LPWMS) used in a scaled fire test conducted in a section of a scaled down road tunnel. The length, width, and height of the tunnel were 6 m, 2.4 m, and 2 m, respectively, which are in a ratio of 1:4 to the dimensions of an actual tunnel. The LPWMS used a pump pressure of 5.5 bar, and the system configuration was designed according to the pressure generated by the pump. Without a ventilation fan, the fire suppression time was 275 s, and amount of water required to fully suppress the fire was 696.67 L. When a ventilation fan was used, the maximum temperature location was moved from the center of the 6 m long tunnel toward the air inlet end of the tunnel (upstream). While this study will find the performance of the LPWMS in suppressing a fire in a small section of the Ismailia tunnel, determining the times spent and the amount of water consumed in the various stages of fire suppression, and in addition to studying the effect of the ventilation fan on These results and the location of the maximum temperature in the tunnel.

2019 ◽  
Vol 56 (3) ◽  
pp. 1315-1352 ◽  
Author(s):  
Roberto Bellas ◽  
Miguel A. Gómez ◽  
Arturo González-Gil ◽  
Jacobo Porteiro ◽  
José L. Míguez

2001 ◽  
Author(s):  
G. Su ◽  
J. G. Quintiere ◽  
N. Schultz

Abstract The objective of the project is to develop water mist extinguishments design by scaling. The report describes the requirement and criteria of scaling fire, scale model, and the results of suppression for a developing water mist system design. The Maritime Safety Committee Draft Circular, MSC 914 is used as a basis test to evaluate a water mist design. A series of three full-scale tests related to MSC 914 were performed: fire only, fire with steel trailers, and fire with steel trailers and combustible commodities. A simulation was accordingly studied. Then, a scaled water mist design was tested in the scale model to find the characteristics needed for suppression in terms of pressure, water flow rate, droplet size, and the spray momentum. Based on these characteristics, a candidate nozzle will be selected for the full-scale MSC 914 test. The results so far show that the water mist system can effectively suppress the fire in scaled MSC 914 model. The full-scale MSC 914 is scheduled for September 2001. Therefore, the final answer is still pending until then. Scaling results are confirmed for temperatures, heat flux and flow for the MSC 914 fire without water add in.


Author(s):  
Jun Guo ◽  
Haibin Wang ◽  
Yuanhua He

Abstract The fire hazard of lithium-ion batteries (LIBs) poses a serious threat to their transportation and use. The purpose of this study is to investigate the efficiency of low-pressure twin-fluid water mist (TFWM) on suppressing lithium-ion battery fires. Experiments were executed to research the effect of working pressures and release stages on extinguishing the fire. Aqueous vermiculite dispersion (AVD), a commercial agent that was specifically designed to extinguish battery fires, was chosen to compare with the fire suppression performance of TFWM under the same conditions. The results indicate that the type 21,700 LIB fires could be controlled by applying the water mist within 10 s. The cooling ability at various working pressures (0.4, 0.8, 1.0, and 1.2 MPa) demonstrated an increase in inhibitory effects as the working pressure increased, and the optimal pressure was 1.2 MPa. The results further show that the extinguishing ability of the TFWM was better than the AVD agent. When the water mist was applied at the optimal working pressure, the surface temperature, flame temperature and concentration of CO reduced more significantly, compared with the AVD agent. Therefore, the TFWM shows considerable merit as a candidate to fight LIB fires.


2016 ◽  
Vol 8 (1) ◽  
pp. 213-224
Author(s):  
Norbert Tuśnio ◽  
Paweł Wolny

An example of modern water mist extinguishing technology is presented in the article. Water mist systems are firefighting systems which uses very fine water sprays. The smallest water droplets allow a water mist to control, suppress or extinguish fires by cooling both the flame and hot gases by evaporation, displacing oxygen by evaporation and reducing radiant heat through the small droplets themselves. The effectiveness of water mist systems in fire suppression depends on its spray characteristics, which include the droplet size and distribution, flux density and spray dynamics, phase of fire development, fire size and the ventilation conditions. The COBRA (known as PyroLance in USA) systems presented use of a cutting extinguisher is a fire extinguishing technique that combines abrasive waterjet cutting with water spray extinguishing, through a single handpiece or nozzle. The firefighter approaches the fire from outside the main fire area, then uses the cutting action to drill a small hole through a barrier such as a door, wall, roof or floor. Switching to a water spray then allows the fire to be fought, as with a conventional fog nozzle. An analysis of the benefits of using high-pressure water mist in conjunction with new firefighting tactics is described. State Fire Service should aim to minimize water consumption and thus reduce the post-fire losses, take care of environmental protection and improve safety conditions for firefighters.


2018 ◽  
Vol 245 ◽  
pp. 11001 ◽  
Author(s):  
Nadezhda Kropotova ◽  
Alexander Arakcheev ◽  
Leonid Tanklevskiy ◽  
Anton Tanklevskiy

The article contains the main results of the creation of a nozzle of improved design research work. To improve application efficiency of low-pressure nozzle of water mist in automatic fire-extinguishing system (AFS), the construction of centrifugal nozzles with swirl worm screw inserts was changed. The construction features of this sprayer, methods of its testing and obtained results these tests characteristics are presented.


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