The Increase of Fire Extinguishing Efficiency of Gas-Aerosol Binary Mixture Using Shock Waves
Journal Title: Safety & Fire Technology - Year 2017, Vol 46, Issue 46
Abstract
Objective: Determination of the n-heptane diffusion flame-extinguishing efficiency of the combined method which uses a fire extinguishing aerosol, CO2 gases (N2) and the simultaneous impact in their environment of shock waves. The identification of a possible extinguishing mechanism for this method. Methods: In order to determine the possibility of extinguishing the diffusion flame of n-heptane by the combined use of CO2 or N2 gases, aerosol and the shock wave created by the explosion of the pyrotechnic charge, an experimental chamber was set up with a volume of 0.5 m3. Inside the chamber, a shock wave generator was installed, and a crucible with n-heptane was placed at a distance of 1.75 m from it. The gas was fed to the chamber through a gas meter. The pressure in front of the shock wave was measured with a BMP-180 pressure and temperature sensor for the Arduino controller, which operates on a piezoresistive basis. The photographic documentation of the extinguishing process by the combined action of aerosol, CO2 and N2 gases, and a shock wave was done using the Nikkon 1j4 camera with a frame rate of 1200 frames per second Results: The scientific aspects of the increase in the fire-extinguishing efficiency of the gas-aerosol mixture are theoretically substantiated and experimentally confirmed in this paper. Accordingly, the combined impact of a series of shock waves and CO2 or N2 gases mixed with aerosol on the flame of n-heptane inside a chamber, leads to a significant increase in the extinguishing efficiency of such a method. It has also been demonstrated that the extinguishing aerosol concentrations decrease 8 times, and the gases concentration in the binary mixture with the aerosol decreases 4,6 times for CO2, and 4 times for N2 in a relation to their individual extinguishing concentrations when the diffusion flame of the n-heptane is exposed to a series of 3 shock waves with a frequency of 10 Hz and a total power of only 240 Pa. Conclusion: The characteristics of extinguishing the diffusion flame of n-heptane under the conditions of a special chamber were determined experimentally using the proposed combined extinguishing method. The tests have shown that the time for the onset of fragmentation decreases significantly after exposure to a series of shock waves, and the flame is then detached and dispersed at much lower concentrations of aerosol and gas mixture, which leads to faster extinguishing.
Authors and Affiliations
Vladimir Balanyuk
An Analysis of Water Supply System Requirements to Enhance Fire Safety in High Rise Residential Accommodation
Aim: The objective of this paper is to present the requirements of firefighting water supply systems with special focus on high residential buildings and firefighting equipment in such buildings, according to regulations...
Application of Computational Fluid Dynamics CFD for Modeling of Protection of Premises by Fixed Gaseous Extinguishing System
Aim: The problem of fire safety of areas protected by fixed gaseous extinguishing system is discussed. Increasing the accuracy and reliability of the modeling of gas extinguishing process can be achieved by using methods...
Działania ratownicze komponentu medycznego Polskiej Ciężkiej Grupy Poszukiwawczo-Ratowniczej (HUSAR Poland) podczas akcji po trzęsieniu ziemi w Nepalu w roku 2015
Cel: Autorzy artykułu, uczestnicy akcji Ciężkiej Grupy Poszukiwawczo-Ratowniczej Państwowej Straży Pożarnej (HUSAR Poland) po trzęsieniu ziemi w Nepalu w 2015 r. na podstawie prezentowanego studium przypadku dokonali pró...
Rescue Operations of the Medical Component of the Polish Heavy Urban Search and Rescue Unit (HUSAR Poland) During the Mission After the 2015 Earthquake in Nepal
Purpose: Based on a case study, the authors, members of a heavy urban search and rescue unit (HUSAR Poland) of the State Fire Service (SFS), who participated in relief operations in the aftermath of the 2015 Nepal earthq...
A Multi-Storey Car Park Fire – Was the Fire Strategy at Fault?
Introduction: At the beginning of 2018, a massive fire affected a multi-storey car park in Liverpool. The car park serves a nearby major arena that was hosting a horse show at that time. Fortunately, there were no fatali...