The weather is hot, the storage and transportation of hazardous chemicals should be protected from high temperature

It is hot in summer, and the risk of accidents with hazardous chemicals such as flammable and explosive is high. The Provincial Department of Emergency Management reminds enterprises that the summer with high temperature and humidity is the season of frequent fires and explosions of hazardous chemicals. It is necessary to control the temperature and humidity during storage and transportation, especially to prevent accidents caused by excessive temperature.

Four major factors lead to frequent occurrence of high temperature and weather hazards

Why do hazardous chemical fires often occur in high temperature seasons? According to the Provincial Emergency Management Department, the expansion coefficient of flammable liquids in hazardous chemicals is generally large. When stored in a closed container, the volume expands after being heated, and the vapor pressure increases, which increases the internal pressure of the container. If the pressure exceeds the container can withstand, it will cause the container failure or even rupture. If the liquid expands beyond its capacity, it will overflow, and if the gas expands, there is a danger of explosion.

The increase in summer temperature makes the evaporation rate of the liquid faster. The higher the temperature, the higher the concentration of vapor on the liquid surface, the greater the possibility of forming an explosive gas mixture with the air, and the greater the risk of fire and explosion. Therefore, when the ambient temperature exceeds the boiling point of the flammable liquid, danger is prone to occur.

Affected by environmental factors such as temperature and humidity, many hazardous chemicals are easily decomposed after being heated, releasing oxygen or even oxygen atoms, oxidizing other substances, and releasing a lot of heat at the same time. If the ventilation is poor, the heat will accumulate and not dissipate, causing the temperature to rise, which will accelerate the oxidation rate, generate more heat, and promote the temperature to continue to rise. When the temperature reaches the self-ignition point of the substance, it will spontaneously ignite.

In addition, due to the complex characteristics of hazardous chemicals, the exothermic reaction of some hazardous chemicals is difficult to cool down and control the temperature, which is prone to over-temperature phenomenon.

Storage: Keep the temperature in the warehouse below 28°C

Hazardous chemical warehouses should use non-heat-conducting refractory materials as insulation layers for roofs and walls, and the eaves should be properly lengthened to prevent sunlight from entering the warehouse. The wall of the warehouse should be properly thickened, windows should be opened frequently, indirect ventilation holes should be used, double doors and double roofs should be set up. The window glass is painted blue or frosted glass.

It is necessary to pay attention to control the humidity, set up a humidity recording device, configure humidity control equipment such as ventilation and dehumidification, and correctly adjust and control the humidity in the warehouse according to the conditions of the warehouse and the needs of the stored items.

The temperature also needs to be controlled. It is necessary to set up a water storage roof for the warehouse or set a cooling water pipe on the warehouse roof. When the temperature is above 30 °C, spray water to cool down, so that the temperature in the warehouse is kept below 28 °C. Laying stone sacks on the roof of the warehouse can increase the thermal insulation performance, and the roof, exterior walls and window glass of the warehouse can also be painted white to reduce the absorption of radiant heat. Depending on the nature and packaging of the items, in some warehouses, well water can be poured on the ground, ice cubes can be placed on the ground, and air conditioners can be installed to cool down when conditions permit, or windows can be opened in the morning and evening to let in cold air, and doors and windows are closed at noon to prevent Hot air enters.

A cooling device should be installed on the top of the storage tank. When the temperature reaches above 30 °C, the cooling water pump should be turned on to spray and cool down. The storage tank should not be too full, and 5% to 10% of the volume space should be reserved to prevent the hazardous chemicals in the barrel from being heated and expanding and causing combustion or explosion accidents. If the storage tank needs to be temporarily stored in the open air under special circumstances, the sunshade should be built with non-combustible materials, and sometimes a leather pipe should be used to spray water regularly to cool down.

Transportation: choose the right time and temperature

When transporting hazardous chemicals, shed poles and awnings should be installed on the vehicle to ventilate and protect from light, especially to prevent direct sunlight. According to the nature of hazardous chemicals, the vehicle is equipped with corresponding fire fighting equipment. According to the characteristics of the goods, choose a suitable time for transportation at a suitable temperature. For example, if the flash point of the flammable product is below 28°C and the temperature during the day is higher than 28°C, it should be transported at night.

When emergencies such as vehicle failures, accidents, spillage of goods, etc. occur, they shall be properly handled according to the different properties of the goods, such as explosion, flammability, corrosion, high toxicity, radiation, etc., in accordance with the corresponding emergency response plans and operating procedures. If the vehicle obstructs traffic and is difficult to move, the hazard warning lights should be turned on according to regulations. Warning signs should be set up 50 to 100 meters behind the car on ordinary roads, and 150 meters behind the car on expressways. .

If it cannot be disposed of in the early stage, the vehicle should be parked in a place as open as possible, away from crowds and water sources, and a timely report should be made. When reporting, the name, shape, quantity and leakage of the dangerous goods should be detailed, so that the relevant departments can deal with them effectively in the first time.