【科普】夏季高溫來襲，?；穬?chǔ)存有哪些安全措施？
Source: Yongkang Zhongyi Manufacture & Trade Co., Ltd.Publication time：2020-08-03
There are many extreme bad weather such as high temperature and thunder and lightning in summer, which will affect the safety of personnel, equipment and chemicals. Improper response can easily lead to accidents. How to ensure the safety of storage of hazardous chemicals in summer, come to learn about it.
Why do most of the hazardous chemical fires occur in high temperature season?
01
The volume pressure of dangerous chemicals increases with the increase of temperature
The expansion coefficient of flammable liquid is generally large. When it is stored in a closed container, its volume will expand after being heated. At the same time, the vapor pressure will increase, which will increase the internal pressure of the container. If it exceeds the pressure that the container can bear, it will cause the failure or even rupture of the container. In the high temperature season, the drum phenomenon of iron drums containing flammable liquids and the cracking of glass containers are caused by the thermal expansion of stored liquids. If the container is open, the liquid will overflow if it expands beyond its capacity.
02
The higher the temperature, the faster the liquid evaporates
The expansion coefficient of flammable liquid is generally large. When it is stored in a closed container, its volume will expand after being heated. At the same time, the vapor pressure will increase, which will increase the internal pressure of the container. If it exceeds the pressure that the container can bear, it will cause the failure or even rupture of the container. In the high temperature season, the drum phenomenon of iron drums containing flammable liquids and the cracking of glass containers are caused by the thermal expansion of stored liquids. If the container is open, the liquid will overflow if it expands beyond its capacity.
02
The higher the temperature, the faster the liquid evaporates
The evaporation rate of different liquids varies with temperature, boiling point, specific gravity and pressure. The higher the temperature, the faster the flammable liquid evaporates, the higher the vapor concentration on the liquid surface, the greater the possibility of forming explosive gas mixture with air, and the greater the risk of fire and explosion. The difficulty of flammable liquid evaporation is expressed by boiling point. The lower the boiling point is, the stronger the evaporation of the liquid is. Therefore, when the ambient temperature exceeds the boiling point of flammable liquids, it is easy to be dangerous.
03
Increasing temperature accelerates oxidative decomposition and spontaneous combustion
Due to the influence of temperature, humidity and other environmental factors, many dangerous chemicals are easy to decompose when heated, releasing oxygen or even oxygen atoms, which oxidizes other substances and releases a lot of heat at the same time. If the ventilation is not good, the heat accumulation will not disperse, causing the temperature to rise, which will accelerate the oxidation rate, produce more heat, and promote the temperature to continue to rise. When the temperature reaches the spontaneous combustion point of the material, it will spontaneously ignite.
What are the safety measures for the storage of hazardous chemicals in summer?
01
The storage warehouse should be qualified
Non thermal conductive refractory materials should be used as the thermal insulation layer of the roof and walls of the hazardous chemicals warehouse, and the eaves should be appropriately lengthened to prevent sunlight from entering the warehouse; the warehouse walls should be appropriately thickened, windows should be often opened, indirect ventilation holes should be used, and double doors and double roofs should be set; the window glass should be painted blue or frosted glass should be used.
02
Hazardous chemicals should be classified and stored
Hazardous chemicals shall be stored in different categories, warehouses, pieces and shelves. It is strictly forbidden to mix the articles with different properties, different fire extinguishing methods and easy to cause spontaneous combustion in one place.
When storing articles, the stacking shall not be too high, too large or too dense. A certain distance shall be kept between stacks, between stacks and walls, columns, roof beams and electric lamps. Fire fighting passageways shall be reserved, and excessive storage is not allowed.
03
The temperature should be strictly controlled
Water storage roof is set for the warehouse or cooling water pipes are set on the roof of the warehouse. When the temperature is above 30 ℃, spray water to cool the temperature in the warehouse to keep the temperature below 28 ℃.
Laying gunny bags on the roof of the warehouse can increase the heat insulation performance of the roof. It can also paint the roof, exterior wall and window glass white to reduce the absorption of radiant heat and achieve the cooling effect.
According to the nature and packaging of the goods, we can also pour well water and ice on the ground of the warehouse, and install air conditioning to cool down if possible. Some warehouses can open windows in the morning and night for ventilation, put in cold air, and close the doors and windows at noon to prevent hot air from entering.
04
Take cooling measures for open storage yard and storage tank
Barrels of flammable liquids should be placed in buildings to prevent direct sunlight. In special cases, if it needs to be stored in the open air temporarily, the non combustible materials should be used to build the sunshade, and sometimes the skin pipe should be used to spray water regularly to cool the temperature.
A cooling device should be set on the top of the storage tank. When the temperature reaches above 30 ℃, the cooling water pump will be turned on for spray cooling. The storage tank should not be too full, and 5% - 10% of the volume space should be reserved, so as to prevent the combustion or explosion accidents caused by the thermal expansion of dangerous chemicals in the tank.
05
Lightning protection facilities should be provided
The warehouse of dangerous chemicals is generally located in the edge area of the unit or city, and keeps a certain distance from other buildings around it. Thus, an open area is formed around the warehouse, which is easy to be struck by lightning. Therefore, the warehouse should be installed with lightning protection device to prevent fire accidents caused by lightning strike.
06
Strengthen personnel management
The personnel in charge of dangerous chemicals warehouse must be trained in safety, pass the examination and take up the post with certificate. The warehouse management personnel shall inspect the warehouse regularly, and solve the problems found in time to ensure the safety.