In recent years, with the rapid development of China's economy, the occurrence of hazardous chemicals warehouse fires is on the rise. For example, in 1993, 18 people were killed, 873 were injured, and 136 people were seriously injured, including 41 firefighters and soldiers, and 2 direct economic losses500 million yuan. In 2015, 165 people were killed in the "8.12" Ruihai dangerous goods warehouse accident in Tianjin Port, including 24 active firefighters and 75 firefighters in Tianjin Port, 8 people (5 firefighters in Tianjin Port, 3 firefighters in their families) missing, 798 people were injured, and direct economic losses were 686.6 billion yuan. The occurrence of fires in these hazardous chemical warehouses not only caused heavy losses to people's lives and property, but also paid a heavy price for firefighters. In fighting the fire in the hazardous chemicals warehouse, how to reduce the loss of national property and minimize the fire officers and soldiers has become an urgent problem in front of the fire officers and soldiers.
1. Fire characteristics of hazardous chemicals warehouseRapid combustion, prone to ** combustion
1) In the hazardous chemicals warehouse, the hazardous chemicals generally stored have the characteristics of large storage capacity, flammable and easy to burn, once a fire occurs, it burns rapidly, and it is easy to cause a series of first-class combustion.
2) A fire in a hazardous chemicals warehouse is very likely to cause most of the stored hazardous chemicals to participate in the combustion, the fire is rapid, the spread is rapid, and it will cause the roof of the warehouse to burn through in a short period of time, and even cause the collapse of the warehouse building.
3) The barrels, tanks and pressure vessels containing flammable and combustible liquids in the hazardous chemicals warehouse are subject to high temperatures, and may burn at any time. The vapor, combustible gas, combustible dust, etc. of flammable and combustible liquids are very prone to high-temperature combustion.
The physical and chemical properties of hazardous chemicals are different, and the development of fire is changeable
1) There are many types of hazardous chemicals, each with different characteristics, once the fire interaction causes the fire situation to be complex, it is easy to cause sudden changes.
2) In the hazardous chemicals warehouse, some are flammable when exposed to water, some are flammable and explosive, and some are radioactive, strong corrosiveness and toxicity, which have higher requirements for the selection of fire extinguishing agents and the safety of fire officers and soldiers.
3) Once a fire breaks out in the hazardous chemicals warehouse, the burning flame and strong heat propagation pose a serious threat to the adjacent hazardous chemicals warehouse area.
4) In the fire of hazardous chemicals warehouse, when extinguishing or evacuating hazardous chemicals, if the fire extinguishing agent cannot be used correctly or the items with conflicting properties are accidentally mixed or contacted during the evacuation process, it is very easy to occur, causing new fire points and aggravating the complexity of the fire fighting and rescue scene. For example, at 13:20 on August 5, 1993, a fire accident occurred at No. 6 warehouse in Qingshuihe, Luohu District, northeast of Shenzhen. Due to the mixed storage of sodium sulfide, sulfur, toluene, ethyl ester, barium carbonate, porous ammonium nitrate, insurance powder, methyl ester, phosphoric acid, sodium nitrite, alcohol, potassium hydroxide and other mixed storage in the hazardous chemicals warehouse, caused by chemical reactions, many times have occurred, resulting in particularly serious fire accidents.
Hazardous chemicals are highly toxic, large in quantity, and difficult to extinguish
1) Most of the hazardous chemicals and their combustion products in the warehouse are toxic to the human body, and even have radiation, which brings great difficulties to the fire fighting work.
2) Once a fire occurs in the hazardous chemicals warehouse, the container containing the hazardous chemicals is damaged and leaks, and it is easy to decompose or evaporate toxic substances under combustion or high temperature conditions, such as dimethyl sulfide can decompose at high temperature to produce toxic sulfur oxide smoke, ethyltrichlorosilane can decompose at high temperature to produce phosgene, and trifluorotoluene can volatilize toxic gas with aromatic odor at room temperature.
3) Due to the damage to the packaging, the hazardous chemicals in the warehouse spontaneously combusted, causing disasters, and then releasing a large number of heat and toxic substances, which further aggravated the leakage and damage of the hazardous chemicals and made the fire develop rapidly.
4) Some hazardous chemicals react with water and other fire extinguishing agents, which further aggravates the development of the fire and produces a large number of toxic substances, which brings serious difficulties to fire fighting and rescue.
5) In the event of a fire in the hazardous chemicals warehouse where nuclear materials are stored, it is very easy to cause the leakage of nuclear materials.
2. Deficiencies in fighting fires in hazardous chemicals warehousesFire detection is inadequate
Once a fire breaks out in the hazardous chemicals warehouse, the burning is violent, the spread is rapid, after the fire brigade arrives, the commander is anxious to extinguish the fire, and fails to effectively carry out fire reconnaissance, resulting in the ignition of the burning material at the scene of the fire is unknown, the quantity is not accurate, the fire extinguishing agent can not be effectively selected, blindly spraying water or foam, once a violent chemical reaction occurs, it will cause the fire to further expand.
The number of fire trucks equipped with special fire extinguishing agents is insufficient
Hazardous chemicals warehouse part of the unit one-sided pursuit of efficiency, fire safety awareness is weak, hazardous chemicals mixed phenomenon is serious, once a fire occurs, due to the huge quantity, some substances physical and chemical properties contradict each other, can not choose a single fire extinguishing agent to extinguish, such as many fire squadrons are not equipped with dry powder fire trucks.
The amount of fire extinguishing agent is insufficient to meet the needs of fire extinguishing
After the fire in the hazardous chemicals warehouse, the burning is fierce and spreads rapidly, and the fire brigade is required to lay the hose line as soon as possible after the fire brigade arrives at the scene, set up water guns and water cannon positions, and quickly spray fire extinguishing agents for different burning objects, or cooling, or extinguish the fire, and try to control the fire in the initial and development state. In particular, when there is a fire of combustible gas, water combustion substance and alkali metal and alkaline earth metal substance at the scene, carbon dioxide, dry powder, 7150, heptafluoropropane, sand, cement powder and other fire extinguishing agents are urgently needed, which are precisely the least fire extinguishing agents equipped by the fire brigade, and these fire extinguishing agents carried are far from meeting the needs of fire extinguishing.