In fact, this is also a matter of common sense. In the past, liquefied gas tanks were what we often referred to as gas. Now there is more natural gas. At first, we used gas for cooking a lot, and until recently, we used gas for cooking. In a few years, natural gas has slowly spread to the lowest counties. In fact, everyone who has used it knows that it is dangerous. You may not have seen explosions, but you have always seen them in movies, right?
Why do liquefied gas tanks explode?
Let’s first popularize some common sense. A liquefied gas tank is a storage tank used to store liquefied gas. When it is completely filled with liquefied gas, the pressure is very high. If you operate it incorrectly, you will be wrong. Very likely to cause an explosion.
How many firefighters have suffered casualties while dealing with fires or even explosions of hydraulic gas tanks. Here, we should really pay tribute to the fire officers and soldiers~
Liquefied gas is stored at 20 degrees Celsius At that time, its pressure is only 0.8 MPa. If it reaches 40 degrees Celsius, its pressure can reach 1.59 MPa. The maximum pressure of the liquefied gas cylinders we commonly use now is 2.1 MPa.
If the volume of liquefied gas remains unchanged, the pressure will increase by 0.04 MPa for every 1 degree Celsius increase in temperature, so each cylinder can only be filled to 85%. The reason is that even if it is filled to 85%, there will still be 14.5 kilograms of liquefied gas.
The most important point is not to use warm water to heat the cylinder when it is empty, otherwise it will cause a physical explosion.
Nowadays, natural gas transported by pipelines is commonly used for cooking at home, and pipeline natural gas generally does not explode unless the leaked natural gas reaches a certain concentration in a confined space and encounters an open flame.
Four major reasons for the explosion of liquefied gas tanks
Overfilling
As we just said above, liquefied gas has the characteristic of thermal expansion. The specific gravity of liquefied gas It becomes smaller as the temperature increases, and the volume increases.
Since liquid is actually incompressible, if the entire volume of the container is filled with liquefied gas, even if the temperature does not rise much, a large pressure will be generated due to the expansion of the liquid, causing the container to deform and explode.
High-temperature baking
Liquefied gas storage tanks that are roasted by flames are at risk of steam explosion.
On the one hand, the heat of the flame causes the liquid in the device to boil and generate high pressure. On the other hand, the tensile strength of the gas tank drops sharply due to the high temperature. When the pressure reaches the set pressure of the safety valve, the safety valve will rupture. Turn on.
Mechanical collision
Mechanical collision will force the container to be damaged, and the pressure inside the tank will instantly decrease and cause an explosion.
The risk of mechanical collision mainly comes from the derailment and overturning of LPG tankers during transportation, the collision of tankers during transportation, and the impact of surrounding objects on the container.
Equipment defects
If the equipment itself is defective, it goes without saying that a steam explosion is very likely to occur.
Case example: Liquefied gas explosion? A raging fire broke out in the house
A raging fire broke out in a private house on the top floor of a residential building in Zhangpu Old Town, with billowing black smoke accompanied by crackling fire. The noise kept coming out, the anti-theft window was gone, and things kept falling, which was very scary.
Investigation results: The accident was caused by a fire caused by a leakage and explosion of liquefied gas, which caused the wall inside the house to collapse, causing one person to be trapped and sent to the hospital to die after unsuccessful rescue efforts; another person was burned by the fire caused by the gas leakage and explosion.
Are the gas bottles we use at home safe?
The first step: scrapping period
Check whether the gas bottle has reached the mandatory scrapping period. Generally, gas cylinders have a service life of 15 years and are tested every 4 years. They should be scrapped after 15 years.
The second step: Check the periodic inspection mark
According to the provisions of "GB 5842-2006 Liquefied Petroleum Gas Cylinders", the design service life of Liquefied Petroleum Gas Cylinders is 8 years. Since 2007 Cylinders produced after February can only be used for a maximum of 8 years;
The third step: look at the appearance
Look at the appearance for deformation, large-scale rust, scratches, fire marks, and dents. pits, solder joints, etc. If there is, it is an unqualified cylinder and must not be used any further.
Conclusion
For our safety, we must do the following when using liquefied gas:
1. Every time you use liquefied gas, open the cylinder After removing the valve, be sure to check whether there is any air leakage before igniting it for use. After use, first close the gas valve and then the ignition switch.
2. During the inspection, you can only look at the gas meter pointer, listen and smell. Never use a lighter to light it for inspection. If there is air leakage, immediately close the gas cylinder valve and call the ventilation personnel to handle it.
3. If you encounter a sudden fire hazard while using liquefied gas, you should immediately close the gas cylinder valve, then use surrounding objects such as sacks, aprons, etc. to put out the fire, and notify Ventilation personnel.
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End statement: All contents of this article are originally written by the author (Senior Mengluo), and no organization, unit or individual may use them without permission. Reprinted privately, the author reserves the right to pursue legal responsibility