High Temperature
Increased threat to safe storage of hazardous chemicals
Must strengthen security protection
Do an excellent job of preventing heat and cooling
Prevent fire and explosion accidents!
Why is the storage of hazardous chemicals high in high-temperature weather?
-
The increase in temperature increases the volumetric pressure of the hazardous chemical.
Thermal expansion and contraction are general physical phenomena of objects. The internal pressure of the container increases, and if it exceeds the limit that the container can withstand, it will cause the container to fail or even burst. If the container is open, the liquid contained in it expands beyond its capacity and will overflow, resulting in running, running, dripping and leaking. To prevent this from happening, in addition to taking measures to avoid heat and reduce the temperature, it is also necessary to carry out filling according to the specified filling coefficient. As far as the gas is concerned, its expansion coefficient is more significant, and the gas is generally contained in the cylinder. As the temperature rises and the pressure is too high, the cylinder is in danger of explosion.
-
The rise in temperature makes the liquid evaporate faster
The higher the temperature, the faster the flammable liquid evaporates, the greater the concentration of vapour on the liquid surface, the greater the possibility of forming an explosive gas mixture with air, and the higher the risk of fire and explosion. The evaporation rate of different liquids varies with temperature, boiling point, specific gravity, and pressure. The ease with which a flammable liquid evaporates is expressed by its boiling point, the lower the boiling point, the more evaporative the liquid is. Some flammable liquids have very low boiling points, and once the ambient temperature exceeds its boiling point, it is prone to danger.
-
Increased temperature accelerates oxidative decomposition and spontaneous combustion
Affected by environmental factors such as temperature and humidity, many dangerous chemicals are easily decomposed after being heated, releasing oxygen and 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 speed up its oxidation rate, generate more heat, and promote the temperature to continue to rise. When the temperature reaches the spontaneous ignition point of the substance, it will spontaneously ignite.
What are the basic safety measures for the storage of hazardous chemicals?
-
The storage warehouse should be qualified
Hazardous chemical warehouses should use non-conductive refractory materials as insulation layers for the roof and walls, and the eaves should be appropriately lengthened to prevent sunlight from entering the warehouse; the warehouse walls should be appropriately thickened, windows should be opened frequently, indirect ventilation holes should be used, and Double doors, double roof, window glass can be painted blue or frosted glass.
-
Hazardous chemicals should be classified and stored
Hazardous chemicals are generally divided into explosive articles, combustible articles in contact with water, spontaneous combustible articles, flammable solids, flammable and combustion-supporting gases, corrosive articles, oxidants, etc. These items should be classified, stored in separate warehouses, divided into parts, and stored on separate shelves. It is strictly forbidden to mix items with conflicting properties, different fire fighting methods, and prone to spontaneous combustion.
When storing items, the stacking should not be too high, too large or too dense. A certain distance should be maintained between stacks, between stacks and walls, columns, roof beams and electric lights, and fire escapes should be reserved, and excessive storage should not be allowed.
-
Strictly control the temperature
Set up a water storage roof for the warehouse or set up a cooling water pipe on the roof of the warehouse. When the temperature is above 30 degrees Celsius, the warehouse is cooled to keep the temperature in the warehouse below 28 degrees Celsius.
Laying sand and stone sacks on the roof of the warehouse can enhance the thermal insulation performance of the roof. The roof, exterior walls and window glass of the warehouse can also be painted white, and the reflection effect of white on sunlight can be used to reduce the absorption of radiant heat and achieve the effect of cooling.
According to the nature and packaging of the items, well water and ice cubes can be poured on the warehouse floor, and air conditioners can be installed to cool down if conditions permit. In some warehouses, windows can be opened in the morning and at night to let in cold air, and doors and windows can be closed at noon to prevent hot air from entering.
-
Open storage yards and storage tanks to be cooled
Flammable liquids in barrels should be placed in buildings to prevent direct sunlight. In special circumstances, if it is necessary to temporarily store it in the open air, the sunshade should be built with non-combustible materials, and sometimes it is necessary to spray water regularly with a leather pipe to cool down according to the actual situation.
A cooling device should be installed on top of the storage tank. When the temperature reaches above 30 degrees Celsius, the cooling water pump should be turned on for spray cooling. The storage tank cannot be overfilled. Generally, only 90% to 95% of the volume is contained in the tank, and 5% to 10% of the volume space should be reserved, which can prevent the hazardous chemicals in the tank from burning or exploding due to thermal expansion.
-
Install lightning protection facilities
Hazardous chemical warehouses are generally located at the edge of the unit or city, keeping a certain distance from other surrounding buildings. In this way, an open area is formed around the warehouse, which is vulnerable to lightning strikes. Therefore, the warehouse should install lightning protection devices to prevent fire accidents caused by lightning strikes.
-
Strengthen personnel management
Personnel who manage hazardous chemical warehouses must undergo safety training, pass the examination, and hold certificates. Warehouse management personnel should regularly inspect the warehouse, find problems and solve them in time to ensure safety.
Check for these ten problems
-
Low energy warehouse
The fire resistance level of the warehouse is not enough. According to the different risk factors of the stored substances, hazardous chemical warehouses have different fire resistance grade requirements, which should generally be above the second grade.
-
Warehouse changed to factory
Illegal subcontracting or packaging of hazardous chemicals in warehouses.
-
Special library to miscellaneous warehouse
Hazardous chemicals should be stored in special warehouses, but mixed with other items.
-
Taboo warehouse
Store different types of hazardous chemicals in the same warehouse, such as hazardous chemicals with different fire fighting methods, acid and alkali, etc.
-
Private and illegal warehouses
Privately build unapproved hazardous chemical warehouses or rent unsafe warehouses to store hazardous chemicals.
-
Inhabited warehouse
Accommodation or offices in hazardous chemical warehouses.
-
untagged warehouse
Items stored in hazardous chemical warehouses are not marked and labelled.
-
Warehouse with the electrical threat
The power switch of the hazardous chemical warehouse is not set outside the warehouse, and the electrical circuits and lighting fixtures do not meet the explosion-proof requirements.
-
Crowded warehouse
Hazardous chemical warehouse items are placed in disorder, and the “five distances” (top distance, lamp distance, wall distance, column distance, and stack distance) are insufficient. Flammable items should be placed at a fire distance.
-
Open-air warehouse
Hazardous chemicals are stored in the open air without any protective measures.
Article source: https://mp.weixin.qq.com/s/4ovsj5Bsc83LaB_oZ9tSJA
