CO2 FIRE SUPPRESSION SYSTEM

Fire Safety Science, 2003

Understanding suppression mechanisms of different fire-suppressing agents including CF 3 Br (Halon 1301) and inert gases is useful for their efficient use and for developing new agents. Because of the similarities between unsteady jet diffusion flames formed over the cup burner and uncontrolled fires, it is believed that studies of fire-suppressing agents in the former system could provide valuable information on the behavior of such agents in actual fires. In the present study, suppression characteristics of CO 2 were investigated in two flame systems: 1) a periodically oscillating, methane-air jet diffusion flame formed over a cup burner, and 2) a steady-state planar flame formed between opposing jets of fuel and air. A detailed chemical-kinetics model having 31 species and 346 elementary-reaction steps was used. Calculations made for the cup burner yielded a flame-flicker frequency of about 10 Hz. The suppression mechanisms promoted by CO 2 were investigated by adding CO 2 to the airflow, while maintaining the total flow rate constant, for both the cup-burner and opposed-jet flames. In the cup-burner flame, the addition of CO 2 reduced the flame temperature to ~1620 K at suppression. Addition of CO 2 destabilized the flame base, which then moved downstream in search of a new stabilization location. For CO 2 volume fractions greater than 14.5 %, the flame base moved out of the computational area, as it could not find a stabilization point within this domain. The unsteady flickering motion of the flame and higher concentrations of CO 2 accelerated this quenching process through blowout. Even for very high concentrations of CO 2 , the calculations did not yield simultaneous quenching of the entire cup-burner flame. On the other hand, the opposed-jet flame was extinguished through the global extinction of flame chemistry. The low-strain (30 s -1 ) opposed-jet flame extinguished for CO 2 volume fractions > 16.4 %, while the moderately strained (90 s -1 ) flame extinguished for volume fractions > 10.4 %. Both the opposed-jet flames extinguished nearly at the same flame temperature (~1580 K), indicating that the extinction limits in these flames are primarily controlled by chemical kinetics.

1996

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five or ten pound container of Class-D extinguishing agent as a precaution. Pure metals such as potassium and sodium react violently (even explosively) with water and some other chemicals, and must be handled with care. Generally these metals are stored in sealed containers in a non-reactive liquid to prevent decay (surface oxidation) from contact with moisture in the air. WHEN NOT TO FIGHT A FIRE? Never fight a fire: ▪ If the fire is spreading beyond the spot where it started ▪ If you can't fight the fire with your back to an escape exit ▪ If the fire can block your only escape ▪ If you don't have adequate fire-fighting equipment In any of these situations, DON'T FIGHT THE FIRE YOURSELF. CALL FOR HELP. HOW TO EXTINGUISH SMALL FIRES Class A-Extinguish ordinary combustibles by cooling the material below its ignition temperature and soaking the fibres to prevent re-ignition. Use pressurized water, foam or multipurpose (ABC-rated) dry chemical extinguishers. DO NOT USE carbon dioxide or ordinary (BC-rated) dry chemical extinguishers on Class A fires. Class B-Extinguish flammable liquids, greases or gases by removing the oxygen, preventing the vapours from reaching the ignition source or inhibiting the chemical chain reaction. Foam, carbon dioxide, ordinary (BC-rated) dry chemical, multipurpose dry chemical may be used to fight Class B fires. Class C-Extinguish energized electrical equipment by using an extinguishing agent that is not capable of conducting electrical currents. Carbon dioxide, ordinary (BC-rated) dry chemical, multipurpose dry chemical fire extinguishers may be used to fight Class C fires. DO NOT USE water extinguishers on energized electrical equipment.

2020

Manufacturing Analysis of CO2 based Fire Extinguisher

2014

Suppression is used in industrial situations where other mitigations means are inadequate. A number of suppression techniques exist but, today, most of them use an extinguishing powder like sodium bicarbonate. In this paper, a physical analysis of the action of this particular suppressant is proposed and compared to that of radically different inert powders like magnesium oxide. The incidence of the particle size is discussed. The results of the analysis are compared to specific experimental data produced on purpose using a 1 m3 vessel and methane-air mixtures

Chemetron, 2008

Sistema de extinción por CO2

2019

1, 2, 3, 4Chemical Engineer, Loni, Maharashtra, India ---------------------------------------------------------------------***--------------------------------------------------------------------Abstract Carbon Dioxide(CO2) with increasing the crisis for ecology and nourishing to extinguish the planet also known as the greenhouse gas. The power plants play the major role to the emission of the flue gas containing CO2. To evade such environmental issue with its mitigation by the methods of pre as well as post combustion in various power plants for the capture of CO2 that uses amine as base. More the CO2 accumulates in the atmosphere more the climate heats up, so to get rid of such crisis towards the environment, there was an increase in the chase of research to capture CO2 from the environment. The post combustion method is the most widely used in various power plants and it’s quite similar to the desulphurization. To overcome such technique towards future prospective by developing so...

Fire Safety Science

Full-scale experiments are conducted to study the effects of different water-based indirect initial attack methods on the compartment environment and firefighter during compartment fire suppression. Hot layer temperatures typical of room fire conditions are developed in the test compartment using wood cribs. Five suppression methods including straight stream, penciling, continuous wide and narrow fog, and a wide angle burst method are examined for two different spray angles and nozzle pressures. Temperatures, heat flux, gas velocity, and gas concentrations are monitored for the duration of the experiment in the fire compartment. Realistic, yet extreme, fire conditions are repeatedly established in the test compartment, with the fuel load allowing up to nine tests per fire. Differences in average compartment temperature before and during suppression indicate that penciling tactics provide little cooling of the compartment. In narrow fog attacks, the hot layer is pushed toward the floor, resulting in increased temperatures in the lower layer, generally an undesired result. Wide angle fog methods have greater impact on compartment temperature as compared to straight stream or narrow fog methods; however, they may also result in large increases in temperature at the firefighter. Wide angle burst tactics less effectively cool the compartment gases than continuous methods, but also lead to less impact on the firefighter. Greater numbers of bursts increase cooling of the compartment, but at the expense of increased impact on the firefighter. Including impact on the firefighter, continuous straight stream methods, at a nozzle pressure of 700 kPa and aimed to the top of the rear compartment wall, appear the best choice for initial attack on fires developed in these experiments. Due to variability between real fire scenarios and experiments such as these, significantly more study of the various suppression tactics is required before the most effective methods of suppression can be determined for a given set of fire scenarios.

Journal of Mining Science, 2009

The application of liquid/gaseous nitrogen, which inhibits combustion for preventing, controlling and extinguishing mine fires, is now universally accepted for last 50 y. This paper presents the scientific relevance and selective criteria for use of N 2 in subsurface fire and reviews experiences of N 2 use in Indian coalmines for more than 20 y. The different techniques of N 2 production, its advantages and disadvantages are described briefly. A case study of using N 2 as a preventive material, in goaf area of working panels of blasting gallery (BG) method of mining is also highlighted.

Transportation is the largest source of air pollution in many countries around the world due to the high number of vehicles that are functional on the roads today.