【 Weak current College 】 LPG fire-fighting tactics

Liquefied petroleum gas (LPG) is a lightweight fine after non-polluting fuel in 1912 in the United States developed the first household liquefied petroleum gas stove, LPG gradually been exploited. In 1965, in China's Beijing first to promote the use of liquefied petroleum gas (LPG) in addition, as an industrial raw material, one is widely used as a fuel. Since its inception, LPG accidents shoes see not fresh, the time of the accident. As a result of a violent explosion of combustion, quickly, easily lead to loss of life and major economic loss. 5 March 1998, Xi'an city gas LPG management storage area 11, spherical tanks sewage valve the upper flange seal partial failure, causing a large number of leaks of LPG, diffusion occurs if sparks explosion, fire killed 12 people and 30 others were injured, and direct property damage 477.8 million. Disposal of LPG accidents are often encountered fire brigade and, therefore, to study and grasp such accident disposal technologies and tactics, great practical significance.
　
I. General characteristics: liquefied petroleum gas
1, liquefied petroleum gas composition:
The main ingredients containing propane, propylene, butane, isobutane, butylene polyisobutene, etc, and low molecular classes generally treated LPG main components are: propane, butane and Isobutane.
2. physical and chemical characteristics;
Liquefied petroleum gas for gas at atmospheric pressure, with gas properties, after cooling down and become liquid under pressure after processing, the density increases. Volatile liquid of liquefied gases, liquid strong volatility into gas, its volume expansion of 250-300 times its calorific value, the maximum temperature can reach 1900 ° c, volume expansion coefficient of about water 10-16 times the relative density of air 1.56 times, easy in low-lying and deposition.

Second, liquefied petroleum gas fire characteristics:
1, combustion characteristics, when liquefied petroleum gas for gas burning, high pressure, air flow, combustion, thermal radiation is strong, bright pale yellow flame, when the gas contained impurities, fire star cyclical changes and generate large quantities of products of incomplete combustion.
2. explosion characteristics, LPG explosion risk is large, when subjected to the heat of the sun radiation, or other heat source for heating, due to the pressure rise, explosion, explosion, power greatly, explosions early 2000-3000M/S, 1 kg of LPG explosion equivalent to 4-10 kg of TNT explosive power, and with a deflagration, easy to form a second explosion, the formation of large fires, causing heavy losses.

Third, fire fighting techniques and tactics;
1, gas leakage accidents;
Gas leak often means liquefied gas station tank damage due to loss of valve, pipe rupture or tank rupture, resulting in the leakage of gas. Because it is easy to result of deflagration, great danger.
(1) closing valve fault source plug leaks. When the gas leakage incidents should quickly close the valve, cut off the gas, and to take the appropriate method: If the valve damage, using wet linen sheet or blanket wrapped air leakage, and immediately replace the valve, such as a pipeline rupture or tank rupture, should immediately with wooden wedges in leak-proof and at the same time open the valve, gas leak in the running direction other tank to reduce the pressure to reduce risk.
(2) to start the automatic spray or cooling equipment, gas leak at the break, the cooling pipes or tanks.
(3) control of ignition to prevent accidents. When the gas leakage after turning off all gas diffusion area, cut off the power of fire, stop production activities strictly leakage areas unrelated to the entry, minimizing the accident reason field of fire safety technicians and number, the prohibition to and the use of mobile phone, not explosion-proof walkie-talkies, BP machine and replace it with rubber or shoes to prevent fire and explosion caused by static electricity.
(4) in non-zone set thresholds 50M and relative blockade major road junctions is independent of the traffic, or traffic into and rapid evacuation downwind direction or nearby residents.
(5) fire patrol vehicles arrived at the scene, the prohibition to stick into the surveillance zone, shall be stopped at the safety belt, with flowering or spray jet break up the air and the deposition of deep depression, combustible gas in the dilution of combustible gas in the air content, and do battle readiness, timely processing of all kinds of accidents that may occur.
(6) Elimination of the danger, you should detect the leakage area combustible gas content, making it less than 1.5%, normal value is reached only after the warning, recovery with Satan.
2. fire incident handling and considerations;
When valve, pipe or tank by gas leakage caused by fire, Burns, should immediately take all measures to prevent tempering, caused by the explosion, the specific matters are as follows:
(1) strengthening the structure of objects of cooling, open fixed fire-fighting facilities on tank and pipe for cooling, and reduce the heat radiation, firefighters to the tank or the adjacent pipeline enhance cooling with uniform, not when you can leave blank. Cooling water gun minimum flow rate must not be less than the 6.5 l/sec, and continuous cooling and cannot be interrupted. Water gunmen to cooling water directed toward the cupping, valve and piping on the top of the water to flow to enhance cooling strength.
(2) strengthen the ranks of protection, reduction of thermal radiation on the human body. At higher temperatures the front-line officers and region should wear a fireproof suits, and the Organization of several road water gun defense, by rear personnel frontline officers shooting water shield, enhanced frontline cooling protection.
(3) actively organize evacuation near bottle to prevent high-temperature radiation canned bottle exploded.
(4) promptly cut off the gas source, preparation for sealing and fire-extinguishing powder or high-pressure water stream, in the source cannot be cut off dangerous, should strengthen the tank but today to make it stable combustion, liquefied petroleum gas burned itself out after.