Classification treatment and prevention of the hot

2022-07-30
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Classified treatment and prevention of LPG accidents

LPG is the main domestic fuel for urban residents in China. The storage and distribution stations used to store and repack LPG are all over the cities. Due to the high saturated vapor pressure and low explosion limit of LPG, it is easy to cause leakage during storage and transportation. Once leakage occurs, it is very easy to cause explosion and fire if it is not handled properly, and the consequences are unimaginable. Therefore, it is very important to distinguish the causes and characteristics of various LPG accidents and take appropriate measures to deal with them

1 accidents caused by poor manufacturing and installation quality

1.1 accident characteristics

most of these accidents occurred before the "national pressure vessel rectification" in 1987, especially on LPG storage tanks, tank cars and LPG cylinders produced before the 1980s. Some of these products have improper material selection, some have poor assembly and welding quality, and the weld seam has serious defects such as misalignment, undercut, crack, slag inclusion, air hole, etc. they have been repaired for many times when they are manufactured or do not need to use tape for maintenance, and have not been heat treated. For example, for a 400m spherical tank in a liquefied petroleum gas plant in Jilin City, the steel plate butt misalignment accounts for 56%, and the weld seam undercut accounts for 45.2%. The spherical tank leaked and caused an explosion in DECEMBER1979

most of these accidents are caused by sudden cracking at the weld joint, and a large amount of liquefied petroleum gas is sprayed out. Generally, it is an accident that cannot stop leakage, and the situation is the most dangerous

1.2 treatment method

once the liquefied petroleum gas leaks from the weld of the storage tank, it is necessary to first understand the situation in the station. If there is still space in other storage tanks, the liquefied petroleum gas from the leaking tank can be poured into other tanks with a hydrocarbon pump or into a tank truck. When starting the pump, the electrical apparatus must be explosion-proof. In order to prevent explosion, nitrogen or carbon dioxide can be applied in the power distribution room to replace the indoor air. The automobile tank car cannot be started in the station. The fly ash was tried out in plastic products more than 210 years ago, which can be promoted by people. While pouring the tank, a large amount of flowering water or spray water shall be used to disperse the gas in the station. Within the gas leakage area, a warning area shall be marked out. Open fire is strictly prohibited in the warning area

1.3 preventive measures

to prevent such accidents:

(1) LPG storage tanks, tank cars and steel cylinders must be inspected regularly. If the storage tanks and tank cars have the following defects, they should be scrapped

· the materials are inconsistent with the original design and have defects in use

· main pressure components are rimmed steel or A3 steel

· unclear or deteriorated material

the researchers also expressed their views, opinions and suggestions on the solutions to the problems in additives and forming processing, and carried out systematic research and development on the equipment

· the butt weld adopts single-sided welding and there is incomplete penetration

· improper weld arrangement (such as cross weld), resulting in new defects

· the internal cracks, bubbles and slag inclusions in the weld exceed the standard seriously

· the voltage withstand test is unqualified

(2) at ordinary times, the personnel on duty shall patrol the tank farm regularly, and any abnormal phenomenon of the equipment shall be handled or reported in time

(3) install combustible gas alarm in the station so that leakage can be found in time

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