【 Weak current College 】 liquefied petroleum gas leakage and fire suppression methods---Power By 【 China power house network 】

Article Summary: with the petroleum chemical industry's rapid development, the use of liquefied petroleum gas and more widely. In LPG storage, transportation, filling, use, process, quality problems due to the equipment itself or by the person for illegal operations, resulting in the liquefied petroleum gas leak and cause fire, fire is increased each year, and it is easy to result group dead injury. This article on LP's seven main characteristics are detailed and comprehensive for three common types of disclosure of the reasons it's dangerous to have a clear understanding; and highlights fight such fires of five types of basic methods of fighting the fire from security personnel and vehicle equipment safety, fight for attention in terms of its further describes, for the fire commander provides a more comprehensive reference.
　　
Keywords: liquefied petroleum gas leak causes suppression method characteristics
　　
As the petrochemical industry rapid development, the use of liquefied petroleum gas and more widely. In LPG storage, transportation, filling, use, process, quality problems due to the equipment itself or by the person for illegal operations, resulting in the liquefied petroleum gas leak and cause fire, such fire accident is increased. November 26, 2002 21: 40 p.m., Weifang city, a dormitory for liquefied petroleum gas leakage and explosion occurred, resulting in 9 fatalities, serious injuries, building 4 scrap serious consequences. 27 December 2002, an unit of zaozhuang City quarters occur pipeline gas explosion, killing seven people were killed and seven others injured. 27 January 2003, the building of a community in zhangqiu occur pipeline explosion of liquefied petroleum gas, resulting in 21 people were killed, 8 injured in serious accidents. Therefore, to understand the main characteristics of liquefied petroleum gas (LPG), identify common causes of leaks, for prevention of LPG fires have very important implications. And master the basics of liquefied petroleum gas fire suppression methods, see fighting of the fire commander is the correct decision, scientific basis, under the command of prerequisite for reducing casualties and reduce property damage have very positive.
　　
First, the main characteristics of liquefied petroleum gas
　　
Liquefied petroleum gas (LPG) refers to the oil and gas and oil distillation process proceeds from hydrocarbons, in ambient atmospheric pressure for gas. This kind of hydrocarbon compounds mainly by propane, butane and propylene, butylene and other low molecular weight hydrocarbon mixture, also contains a small amount of impurities. According to the different components, at normal temperature and pressure it's boiling point range is-42.7 ° c to-0.5 ℃. Since the liquid into a gaseous volume to increase by about 250 times that absorb a large amount of heat.
　　
(A) combustion explosive.
　　
Liquefied petroleum gas to combustion, divided into stable combustion and explosion in two forms. Liquefied petroleum gas leak, special performances of continuous combustion phenomena, called stable combustion. Liquefied petroleum gas leakage, the hybrid with air to form an explosive mixture (explosive limit of approximately 2% to 9%), fire explosion, often produces a strong shock wave and high temperature.
　　
(Ii) heavy than air.
　　
LPG gaseous relative density 1.5 ~ 2, the proportion is air 1.5 ~ 2 times. Since than the major leak when liquefied petroleum gas (LPG) will accumulate in the low-lying, or drifting along the ground, once you reach any explosive concentration, fire explosion can occur.
　　
(3) thermal expansion.
　　
LPG liquid density as the temperature and the smaller, the increase in volume. Its liquid volume expansion than petrol, kerosene are large expansion of the water, is 10 ~ 16 times. Therefore, filling LPG cylinders should strictly control the amount of filling, along with the increase in temperature is extremely easy for gas cylinders are splitting.
　　
(Iv) the minimum ignition energy.
　　
Liquefied petroleum gas ignition temperature of approximately 430 ° c ~ 460 ° c lower than other combustible gas, ignition energy, a spark to ignite.
　　
(V) toxic.
　　
Have low toxicity of liquefied petroleum gas, air in the 1% of people in the air for 10 minutes without danger. When the air content reaches 10% of people in the environment in 2 minutes you will anesthesia.
　　
(Vi) live sex.
　　
LPG filling and transportation process easy to produce static, the faster the speed, the more easily generate static electricity.
　　
(VII) corrosive.
　　
Liquefied petroleum gas in containers, pipes, rubber tubing, sealing compounds, have a corrosive effect.

Second, liquefied petroleum gas leak in General.
　　
Throw an LPG fire must meet the following four criteria: 1, liquefied petroleum gas leak; 2, mixed with air; 3, a fire has enough ignition energy; 4, the above three conditions for the interaction. Meet the conditions above 4, LPG fires can occur, but the most basic reason is the liquefied petroleum gas leak. Liquefied petroleum gas leakage caused by the following:
　　
(A) the quality of equipment and installation problems.
　　
Storage tanks, pipelines, valves and other devices exist quality problems; angle valve closes, the ageing of rubber hose is damaged, loose, making the part installation LPG leaks.
　　
(Ii) illegal operation.
　　
The lack of security knowledge, does not understand the nature of the liquefied petroleum gas, contrary to the security operation procedures, instead of using ordinary rubber pipe of high pressure tubes, cylinders, gas-filled to excess or use external tank at high temperature Grill flame directly.
　　
(Iii) transportation vehicle accidents, the sabotage or earthquakes and other natural disasters caused by pipelines, tank leak accident damage, etc.
　　
III. fighting LPG fire of basic methodsBR>
For LPG fire, the fire brigade arrived at the scene, the first chemical explosion has ended, and the fire had spread, has entered a stable combustion phase. This time the key is to prevent secondary explosion and prevent the spread of fire, the fire brigade arrives at the expansion of the scene should be immediately carried out the following work:
　　
(A) to rescue personnel, cooling, gas tank to prevent the explosion.
　　
The first fire brigade arrived at the power should establish the first "Save" guiding principles for must rescue personnel in distress, and then set all fire-fighting power, cooling with water gun, adjacent tank explosion-proof adjacent tank. Especially in fire extinguishing power shortage, the cooling tank to stable combustion, awaiting reinforcements arrived at the scene and then organized forces were wiped out the fire.
　　
(Ii) to clear the obstacles, take a variety of ways.
　　
Reinforcements arrived, to build appropriate increase cooling power, clean up the gas tank around obstacles, opening up the offensive line. And from the periphery to the Centre of the fire, the progressive eradication of LPG tanks around the fire. In the availability of water and other fire extinguishing agent, and to ensure uninterrupted supply of fire, engineering and technical personnel and operators do leak to snuff out ready and take one of the following methods or a combination of methods for extinguishing:
　　
1. cooling and suffocation.
　　
Organization number supported spray or flowering water gun shot-by-side or cross-flow, the flame around the roots of extremely high density and water, while gradually from the bottom up, with move jet of water vapor and absorb a large amount of thermal energy, reduce the ignition point temperature of the diluted liquid petroleum gas concentration, reach the purpose of the flame is extinguished.
　　
2. powder inhibition method.
　　
Dry powder fire extinguishing liquid petroleum gas, fire extinguishing effect significantly faster. In-fighting, dry large capture combustion generated free radicals, and reaction, the nature and stability of molecules to truncate the combustion reaction chains make burning terminated. Use extinguishing agent number depends on the size of the fire, the pressure of high and low and the cooling effect is good or bad, and many other factors, combined with cooling effect of water gun.
　　
3. the quarantine fire method.
　　
In the pipeline and tank valve is not burned, you can take off valve to snuff out of isolation. Operators should avoid wearing suits and carry the necessary fire tools, under the cover of the water gun, close to the device turned off the valve cut off gas supply. When a fire occurred on a smaller storage tank above the leak, and the pipe is in a healthy state, the burning of liquefied petroleum gas in tank transferred to other tank, "cauldron" and burned in the LPG storage tank so that the fire goes out. But this method should pay attention to the skills of fire tank storage should grasp accurately, otherwise easily lead to the spread of fire to expand.
　　
4. water litre stream methods.
　　
On the lower portion of the leaking part in storage tanks, should use existing or temporary installation of mains cable to the tank water, use of water and the proportion of liquefied petroleum gases, liquefied petroleum gas (LPG) float to the rupture of the mouth, so that the water flows out from the rupture of the mouth, then plug the work. Actions to prevent water pressure too large to make the liquefied petroleum gas from tank top safety valve, can be taken at the edges down side injection LPG.
　　
5. emergency lighting method.
　　
In all other ways fail, in order to prevent an explosion, ensure absolute safety, take the lighted method to prevent the explosion limits LPG reached. In personnel evacuated after using tracer bullets or signal gun from poop lit, implementation of control combustion.
　　
4. fighting LPG fire of the
　　
LPG fire damage, harm, it is easy to result group dead injury malignant accident. When you want to set up a time to fight fire command, coordination, enhancement and command, do a coordinated operations, should focus on doing a scene of fighting personnel safety and vehicle safety equipment, and note the following issues:
　　
(A) the fire commander to timely and accurate information, analysis and judgement of the fire monitor storage tank and wind direction, wind power, comprehensive and timely fire changes to make the right decision to deploy and the retreat of the fighting.
　　
Pay attention to the tank explosion of threatened. If the tank is BBQ, physical explosion may occur, and significant explosion precursor: generally, red flame, noise small, relatively safe; flame from red to white noise is small, larger is the precursor of the explosion.
　　
(Ii) fire engine should stop in a location convenient for retreat.
　　
Enter the scene of fighting personnel to be as concise as possible, equipped with insulated clothing, fire suits, empty out, protective equipment, poop, close to the fire station shall not be higher than the level above the centre line of the storage tank, from tank explosion.
　　
(Iii) to ensure that the fire uninterruptedly.
　　
Water gunmen to select good terrain features, masking the body. Close quarters should be taken when attacking the cover layers of cooling. Cooling water should be as top spray to directly affected by the fire on the wall of the radiation threat. Water shooter should at all times maintain liaison with the commanders of the communication.