Why do gas cylinders explode? Causes and consequences of a gas cylinder explosion A new unfilled gas cylinder may explode

Household gas has the same powerful destructive force as TNT! Using gas and neglecting safety measures, we expose our lives, the lives of loved ones and neighbors to mortal danger. How does a gas explosion occur? Take a closer look at the picture:

So why does gas explode? The main reason - improper storage and operation. Industrial defects account for a minimum of tragic cases, which, again, were provoked by operational violations.

For household gas to explode, it must mix with air. The most dangerous concentrations are 30 and 70 percent of gas. If you smell gas, something is wrong. In this case, the leak must be repaired immediately. At the same time, you should remember that you cannot use electricity (do not turn on or off the lights or other devices), you cannot use open fire, or smoke. At the same time, the room should be completely ventilated.

Typical situations in everyday life that lead to explosions:

  • The boiling kettle/pan is stewed gas burner, but gas continues to flow intensively into the room. Accidental spark - explosion and fire.
  • Stored for a long time the cylinder is brought from the cold into a warm room or placed next to a heat source (the same gas stove). There is a sharp change in temperature, the cylinder bursts with internal pressure. A subsequent gas explosion is inevitable.
  • A common misconception is that rupture of a pressure cylinder is possible only in the situation described earlier and only in winter. This is wrong. It is the large temperature difference that has an effect. If in summer you move the cylinder from a cool room to a hot kitchen, the effect will be the same.
  • The rupture of the cylinder occurs due to microcracks that form over time. In the process of corrosion inside(!) the cylinder. If a steel cylinder is beautiful and new on the outside, this does not mean at all that it is in good condition inside. Shake the empty cylinder that contains no gas. Do you feel something rustling there? - this is condensation. It is this, like any moisture, that causes a gas cylinder to rust. Time passes and at one tragic moment the pressure will do its job (described above). This can happen even while filling a gas cylinder. Composite cylinders do not have this disadvantage - there is nothing there to rust.
  • Gas leaking from a crack in a worn out, frayed hose. Leakage from the connection between the hose and the cylinder or stove. Gas gradually fills the room, then again any spark ignites the accumulated propane.

Many other cases can be written, but it's better to see once How does this happen. The surveillance video is impressive. Safety requirements were invented for a reason.

Main reasons for the explosion household gas cylinders are:

  • Violation of norms and rules for refilling household cylinders
  • Violation of the rules for storing and operating gas cylinders

According to standards Gas cylinders must be refilled at specialized stations, where they are filled strictly by weight on special weighing units. This filling of cylinders is carried out to a maximum of 85% of their volume. 15% - buffer zone, intended for the transition of part of the liquid phase into the gaseous phase.

According to statistics, the main share of explosions occurs in the cold season due to big difference temperatures between refueling and operation. However, the temperature difference itself cannot lead to an explosion, since these products have an operating temperature range from -40 to 50 degrees C, and the main reason is violation of the rules for operating gas vessels working under pressure. Such as:

  • lack of timely examination (once every 5 years),
  • refueling at non-specialized points, where refueling is carried out from a conventional gas dispenser, and the degree of filling is controlled by pressure,
  • refilling cylinders with expired service life (40 years),
  • placement of gas containers during storage and operation in common areas.

If the cylinders are not filled at a specialized station, then they are filled to capacity. If such refueling is carried out in the summer, then the temperature of the refueled gas is almost equal to the ambient air temperature. In winter refilling propane cylinders requires special adherence to temperature conditions.

If a cylinder is filled to capacity in the cold and then brought into a warm room, the pressure in it increases sharply, because LPG is characterized high coefficient thermal expansion. If there is no buffer zone in a gas cylinder, the excess pressure has nowhere to go, and it begins to have a destructive effect on the walls of the cylinder and ultimately leads to explosions of gas cylinders in houses.

Gas leak through the valve causes gas to gradually fill the room. That is why, store gas cylinders necessary outdoors, in cabinets specially designed for this purpose, with holes for ventilation. Such storage does not allow household cylinders to overheat, and the presence ventilation holes prevents the creation of an explosive concentration of propane-butane mixture even in the presence of gas leakage through the connecting fittings.

Very often people, especially summer residents, neglect safety and store gas cylinders indoors, next to gas stoves. This leads to overheating of gas cylinders and, as a result, rupture of their walls and explosions. Also, if there is a leak in the hoses or fittings, then the gas, being heavier than air, accumulates in places below floor level and an explosive mixture is formed in the room, which leads to unpleasant consequences, because gas has the same destructive power as TNT.

As a result of the rupture of the flask with gas, in the presence of an open flame or an accidental spark, fires occur. Due to fires that occurred as a result of spontaneous depressurization of containers with liquefied hydrocarbon fuel, not only the perpetrators of the incident suffer, but also neighbors and passers-by.

When the gas in the cylinder runs out, condensate remains behind, which must be drained at special stations. Some people drain it themselves, which also leads to dangerous consequences.

Availability large number casualties and significant destruction in a gas explosion is explained by the fact that fires are characterized by the occurrence of a volumetric flash (explosion), during which excess pressure is formed, leading to injury to people and destruction building structures. The explosion causes the destruction of windows and the opening of doors, which contributes to the unhindered spread of the flame, and the flame front leads to the ignition of flammable objects, forming secondary fires.

Take care of yourself and your loved ones.

Gas cylinders are not the safest products, but in some cases they are the only possible way obtaining heating, cooking, etc.

Although modern polymer composite cylinders are much safer than outdated metal ones, many people are still wary of them. It must be said that their fears are not unfounded. Gas cylinders do sometimes explode, although much less often than it might seem.

The explosion of a gas cylinder in a car or apartment is an emergency that can lead to very serious consequences, especially if there are other products near the exploded vessel. Such an emergency can lead not only to the destruction of property, but also to human casualties. Therefore, if you have to deal with gas cylinders, you should know why this happens.

Most main reason such incidents are a violation of the rules for storing and operating cylinders. If the valve is not closed well enough, gas begins to escape and fill the room. Any accidental spark leads to an explosion and fire in the room.

Another option is to bring the cylinder in from the cold. If you bring the container from the street where it long time was at a low temperature, a sudden change in temperature will cause the gas to expand and increase the risk of leakage.

Therefore, under no circumstances should you place a gas cylinder near a heat source. The build-up of pressure inside the balloon, which is created by the expanding gas, increases the risk of rupture of the vessel.

Microcracks or corrosion of the metal cylinder can form over time. Such damage may not be noticeable from the outside, but from the inside it creates a great danger.

This is another reason not to bring the cylinder from the cold into a very warm room - condensation forms on its surface, which also increases the risk of corrosion and a subsequent accident. If the cylinder is not made of metal, there is no such danger, but this does not mean that the gas cylinder can be handled carelessly.

Dependence of explosion on temperature

Winter is the most dangerous time years for gas cylinders. As mentioned above, sudden temperature changes are one of the main enemies of such containers. The gas, which has the strongest destructive power, almost equal to TNT, can destroy an entire apartment, and the explosion can put people's lives in great danger. Not only the residents of the apartment, but also their neighbors and even just passersby, who at the time of the incident will be in close proximity to the explosion, can be exposed to danger.
If the cylinder was left in the cold, the gas in it is in a liquefied state. If you bring the cylinder into the heat immediately, the gas it contains will quickly turn into a gaseous state and expand greatly. The increased pressure can rupture the container, and since the gas ignites easily, it may not even require additional contact with the flame.

The problem with metal cylinders is that it is extremely difficult to control the gas level in them. An explosion is also caused by the fact that the ratio of gas in the cylinder does not meet the standards. An incorrectly filled cylinder when it gets into more high temperature will certainly be torn apart by gas, which, when expanding, will simply have nowhere to go.

But the simplest and one of the most common causes of explosions is an insufficiently closed valve. The gas is heavier than air - when it comes out of the cylinder, it accumulates at the bottom near the floor, so at human height the leak may be detected too late. Even the smallest spark, static electricity or the contact of two solid objects can cause it to ignite.

How often do cylinders explode?

Every year in our country there are about three hundred accidents caused by the explosion of gas containers. According to statistics, such incidents occur much more often in the cold season due to refueling at low temperatures and subsequent transfer of the cylinder to a warm room.
The drop itself is not so dangerous. The cylinders can withstand a fairly wide range of temperatures - from minus 40 to plus 50 degrees Celsius. The temperature difference is only a “trigger” of an emergency situation.

Among the most common causes of explosions, statistics highlight the following:

  • The cylinders did not undergo inspection (testing and pressure testing).
  • Refueling at gas stations that evaluate the filling of a cylinder not by the pressure in it, but by the weight of the container being filled.
  • Placing gas cylinders in residential premises or other premises in common use.

Consequences of a gas cylinder explosion

The consequences of an explosion in a house can include significant damage and destruction of property, as well as harm to human health and even death. The explosion also causes a fire, which increases its destructive power and makes such an incident even more dangerous for people.
In an explosion in an apartment, as a rule, windows and doors are knocked out, walls and partitions can be destroyed, including bearing structures. Access to oxygen increases the area of ​​fire.

How to avoid an explosion

There are two ways to avoid such an incident as a gas cylinder explosion:

  • Follow the safety regulations and operation of gas cylinders.
  • Refuse metal containers in favor of modern composite-polymer products.

Composite polymer cylinders are not afraid of corrosion, and the walls of the container can become gas permeable as the temperature rises. In this case, the gas slowly leaves the cylinder and dissipates, without reaching such a concentration that a fire occurs. But the main thing is extreme caution when handling gas cylinders.

GAS CYLINDERS EXPLOSIONS, CAUSES AND CONSEQUENCES

G.V. Plotnikova,

Associate Professor of the Department of PTE of the Federal State Budgetary Educational Institution of Higher Professional Education of the Ministry of Internal Affairs of Russia, Candidate of Chemical Sciences, Associate Professor

YES. Bodrov,

special investigator important matters SOBR of the Main Directorate of the Ministry of Internal Affairs of Russia for the Irkutsk Region

According to statistics, about 200 people die annually in Russia due to explosions of household gas cylinders. The consequences of such explosions are comparable to the detonation of a 122 mm artillery shell. Gas cylinders pose a particular danger in case of fire. Fires at facilities where pressurized gas cylinders are used are characterized by various combinations hazardous factors that can lead to catastrophic consequences.

According to statistics, in Russia because of the explosions of household gas cylinders die every year about 200 people. The consequences of such explosions are comparable with the explosion of a 122 - millimeter artillery shell. Of particular danger are the gas cylinders in the event of fire. Fires on the objects, which are used cylinders with gas under pressure, are characterized by the expression of a different combination of hazards, which may lead to disastrous consequences.

An explosion is understood as a phenomenon associated with a sudden change in the state of a substance, accompanied by a sharp sound effect and rapid release of energy, which leads to heating, movement and compression of the explosion products and environment. The occurrence of increased pressure in the area of ​​the explosion causes the formation of a shock wave in the environment with a strong destructive effect.

According to statistics, about 200 people die annually in Russia due to explosions of household gas cylinders. The consequences of such explosions are comparable to the detonation of a 122 mm artillery shell. Metal fragments scatter tens of meters, creating a zone of continuous damage.

Plotnikova G., Bodrov D. Explosions of gas cylinders, causes and consequences

A gas cylinder is a vessel with one or two necks for installing valves, flanges or fittings, intended for transportation, storage and use of compressed, liquefied or dissolved gases under pressure.

For cooking in individually built houses, welded steel storage cylinders are widely used hydrocarbon gases, produced by 25 factories Russian Federation in accordance with the requirements of GOST 15860. Currently, their number is about 40 million.

The main type of gas cylinders (about 85%) are tanks with a capacity of 50 and 27 liters, designed for operating pressure 1.6 MPa (16 atm). According to manufacturers, the range of destruction pressures is for cylinders with a capacity of 5 l - 12-16 MPa (120-160 atm), for 27 l - 7.5-13 MPa (75-130 atm), and for 50 l - 7.5 -12 MPa (75-120 atm). Industrial 40-liter cylinders are designed for a pressure 1.5 times higher than the working gas pressure.

Fires at facilities where pressurized gas cylinders are used are characterized by various combinations of the following dangerous scenarios: thermal effect"fire-flash"; impact of explosion compression wave; the thermal effect of a fireball; thermal effect of a jet torch of burning gas; exposure to fragments of a ruptured cylinder; suffocation as a result of a decrease in the oxygen content in the air when gases accumulate in it in excess; narcotic effect of individual gases, even at low concentrations in the air.

If a cylinder hits domestic gas When the fire occurs, the vessel heats up, which leads to boiling of the liquid phase and an increase in pressure in it. The flame heats the walls of the vessel and weakens their initial strength due to uneven heating of the surface, which, as a rule, leads to the destruction of the vessel. In this case, the vapor from the instantaneous evaporation of the liquid phase ignites and a “fireball” is formed.

As a result of studies carried out in an open area, the following was established: when a 50-liter gas cylinder with liquefied gas enters a fire, its depressurization followed by an explosion occurs within the first 3.5 minutes. In this case, the cylinder rupture, as a rule, occurs along the side generatrix. The maximum radius of scattering of fragments of a cylinder that exploded in an open area is 250 m, the height of the fragments is about 30 m. When a gas cylinder with liquefied gas explodes, a “fireball” with a diameter of 10 m can be formed; due to a decrease in the strength of the cylinder walls, its depressurization occurs at a pressure of 5.3-8.5 MPa (53-85 atm). In the event of a fire, the liquefied gas leaving the cylinder can burn in the vapor, liquid and vapor-liquid phases. Each of them has its own combustion temperature.

The nature of the gas flow from the cylinder can be determined by the color and type of flame: in the vapor phase, the gas burns with a light yellow flame; in the liquid phase the flame is bright orange with the release of soot; combustion in the vapor-liquid phase

occurs with periodically changing flame heights. These signs of a visible flame are indirect characteristics of depressurization of a household gas cylinder.

The main, and at the same time, the most common causes of explosions of gas cylinders are:

Excessive cylinder overfill liquefied gases;

Significant overheating or hypothermia of the cylinder walls;

The penetration of oils and other fatty substances into the cylinder, leading to the formation of explosive mixtures;

Formation of corrosion and rust inside the cylinder;

Impacts on the walls of the cylinder due to their fall, impact during transportation, etc.;

Incorrect filling of the cylinder, leading to the formation of explosive atmospheres;

Excessively rapid filling of cylinders with liquefied gas leads to overheating of the cylinder valve up to 400°C;

Ingress of oils or explosive dust;

Formation of rust, scale, sparking.

Experts identify the reasons characteristic of individual species gases

Gaseous technical and medical oxygen is filled into cylinders in accordance with GOST 949-73 to a pressure of 150 kgf/cm2.

Mixtures of oxygen gas with flammable gases are explosive. Lubricants and grease on surfaces that come into contact with oxygen cause fires. Sealing materials (fiber, nylon, rubber, plastic) can easily ignite in a high-pressure oxygen environment.

When investigating accidents involving oxygen cylinders, the following characteristic features were identified:

Separation of the bottom of the cylinder with radial cracks on it (the thickness of the bottom is approximately 15 mm);

Tearing off the neck of the cylinder;

The cylinder body breaks into small fragments (up to a hundred pieces), which also have cracks;

Only the nut from the connected reducer remains on the cylinder valve; the fitting comes off;

The gasket between the cylinder valve and the fitting completely burns out;

The polycarbonate insert on the brass valve valve burns out or is in a state of hardness that is not inferior to the brass itself;

The valve is in the open state, its thread is jammed in the valve body;

The lower part of the valve screwed into the cylinder is covered with carbon deposits;

The flow area in the brass valve and its components have pink color discoloration from high temperature.

These damages can only occur when a mixture of oxygen and flammable gas ignites, and the pressure in the cylinder instantly increases by

calculations up to 1500-2000 kgf/cm. If there is a full cylinder next to the exploded cylinder, then its detonation destruction occurs with the following characteristic features:

Separation of the bottom of the cylinder;

Tearing off the neck of the cylinder;

The cylinder body is destroyed into 2-3 parts;

The cylinder valve is in working order.

Fig. 1 - 3. Cylinder neck, fragments of the cylinder body, cylinder valve

after the explosion

The vast majority of flammable gas (propane) enters the oxygen tank during gas welding work, at the moment when the oxygen pressure in the cylinder becomes lower than the pressure of the flammable gas (propane) in the gas cylinder and its flow into the oxygen cylinder is possible. Other flammable gases may enter the oxygen cylinder if it is not used for its intended purpose.

It all depends on how much gas gets into the oxygen cylinder. If its quantity is significant, then spontaneous combustion occurs combustible mixture when filling, the cylinder explodes with the destruction of the filling station itself and with human casualties. Emergency depressurization of an oxygen cylinder leads to ignition of oil-soaked building structures and clothing of fire extinguishing participants, as well as to intensification of the combustion process.

Rice. 4 -5. Damage to the cylinder and consequences of an explosion of an oxygen cylinder

A carbon dioxide cylinder may explode when pumping the standard container and then moving the cylinder to warm room. Also, the causes of explosions of cylinders are impacts, falls, heating them sun rays and other heat sources, overfilling of liquefied gas cylinders, improper use in violation of safety regulations, seal failure, malfunction of shut-off valves.

Fig.6. Damage to the cylinder carbon dioxide as a result of an explosion

Cylinders filled with hydrogen are characterized by the following feature in fire conditions. With an increase in temperature (and therefore pressure), hydrogen diffuses into the material of the walls of the cylinder, which entails a loss of the initial strength of the cylinder and its explosion.

When cylinders filled with nitrogen enter the fire zone, the nitrogen pressure in the cylinder increases, which can lead to deformation and destruction of the walls of the cylinder. Cylinders filled with acetylene can explode due to ignition of the acetylene jet, which leads to heating of the cylinder and explosive decomposition of acetylene. Heating acetylene cylinders with external heat sources is dangerous, since this creates high pressure, the process of acetylene polymerization occurs, which is accompanied by significant

release of heat and can lead to explosive decomposition of acetylene. With the progressive decomposition of acetylene, the walls of the cylinder heat up, in some cases to a red-hot temperature. If measures are not taken to sufficiently reduce the pressure in the cylinder, an explosion will occur.

Rice. 7. Consequences of an acetylene cylinder explosion

Acetylene cylinders, unlike technical cylinders used for storing and transporting neutral, flammable and oxidizing gases in a compressed or liquefied state, contain a filler - a porous neutral mass with a capillary structure. The need to use bulk or cast filler is caused by the characteristics of acetylene - it is explosive and fire hazardous in the absence of oxygen or other oxidizing agents.

One of the functions of the porous mass is the reliable localization (extinguishing) of the oxygen-acetylene backfire flame, which is possible when performing gas-flame work. A solution of acetylene in acetone is a phlegmatized mixture of acetylene, while the acetylene-acetone solution is practically incapable of explosive decomposition.

In practice, there are isolated cases of destruction of acetylene cylinders due to reverse impact. It is very difficult to predict how a cylinder will behave when a backfire flame hits it. In this case, the time before the explosive destruction of the cylinder after closing the valve can be either several minutes or several hours. This indicates that localization of the explosive decomposition of dissolved acetylene is not always ensured. The processes of extinguishing or combustion occurring inside a closed cylinder filled with a porous mass are specific, complex, and to date they have not been fully studied.

The main potential danger associated with the destruction of acetylene cylinders is the appearance of damaging factors such as shock waves and fragments, leading to serious consequences.

An analysis of accidents that occur when working with acetylene cylinders and the requirements of current regulatory and technical documents allows us to draw the following conclusions.

Existing scientific and technical documentation does not contain requirements for mandatory protection of individual cylinders from reverse impacts using protective devices.

To protect the acetylene cylinder from blowback when performing gas-flame welding work, it is necessary to install a special protective device, providing delay (extinguishing) of the flame and blocking the flow (outflow of acetylene from the cylinder).

The most common causes of explosions of cylinders with a propane-butane mixture are: excessive overfilling of the cylinder with liquefied gases; significant overheating or hypothermia of the cylinder walls; formation of corrosion and rust inside the cylinder; formation of rust, scale, sparking. Often an explosion of a cylinder with a propane-butane mixture occurs when the gas comes into contact with fire.

The explosion of a propane-butane mixture is accompanied by

high-temperature release of gases (flame), while fragments and parts of ruptured cylinders fly, thermal radiation occurs. In the event of a propane-butane explosion, in addition to the main fire factors ( open fire, elevated temperature environment, toxic combustion products, etc.), as a rule, secondary factors appear: a compression wave formed during the explosion of a cylinder and entailing the destruction of buildings or their individual parts, destruction (or damage) of external and internal water supply systems, fire equipment , stationary extinguishing agents, technological equipment, the emergence of new fires and explosions.

Fig.8-9. Possible damage to propane-butane cylinders

Gas cylinders pose a particular danger in case of fire. In case of fire at facilities where propane-butane cylinders are stored or used, explosions of gas cylinder equipment under pressure often occur. When extinguishing objects with gas cylinders, one should take into account physicochemical characteristics gas used.

When a propane-butane cylinder hits a fire, the vessel heats up, which leads to boiling of the liquid phase and an increase in pressure in it. The flame heats the walls of the vessel and weakens their initial strength due to uneven heating of the surface, which, as a rule, leads to the destruction of the vessel. In this case, the vapor from the instantaneous evaporation of the liquid ignites and a “fireball” is formed.

The dimensions of possible zones of damage from fragments when cylinders are destroyed as a result of an explosion are determined by the flight range of the largest fragments. Thus, the radius of the zones affected by fragments during the explosion of acetylene, oxygen, hydrogen, propane thin-walled cylinders, as well as an acetylene generator and a tank with kerosene is 2500, 2200, 1100, 2100, 200 and 800 m, respectively.

Thus, the analysis, processing and generalization of information about explosions of gas cylinders showed that the main causes of explosions identified by experts are: mechanical damage, overheating, metal corrosion, improper operation, gas leakage.

In percentage terms, the causes of explosions were distributed as follows:

Gas leak - 25%;

Mechanical damage - 16%;

Overheating-15%;

Metal corrosion - 20%;

Incorrect operation - 24%.

Along with this, there are reasons specific to individual species.

NOTES

1. Taubkin, S.I. Fire and explosion, features of their examination. - M. VNIIPO, 1999. -

2. Information agency “Arms of Russia”. - http://www.arms-expo.ru/049051124050055053052052.html

3. Verzilin M.M., Savelyev L.N., Shebeko Yu.N. Tactics of actions of fire departments in conditions of a possible explosion of gas cylinders at the source of a fire: Recommendations - M.: VNIIPO? 2000.

4. Chizhichenko, V.P. Analysis of the causes of explosions of oxygen cylinders / V.P. Chizhichenko // Occupational safety. 2010. No. 4. - Electronic resource: http://www.kislorod.in.ua/index.php/2010-06-21-07-41-11.