Fire and explosion prevention of the hottest steel

Fire and explosion prevention of steel barrel spray painting and drying production line

after China's entry into WTO, China's products are facing global competition. Today, when the problem of quantity has been solved, people have increasingly pursued and relied on high-quality products and services. Packaging products are no exception. While giving full play to the function of packaging to protect commodities, packaging promotes the sales of products and increases the added value of products. The same is true of steel drums as metal packaging. The development of steel drum packaging enterprises has gradually begun to pay attention to the external quality from the original only focusing on the internal quality of steel drums. Because the structure of the steel barrel has been finalized and the crimping has reached the best, the internal quality can basically meet the needs of users. However, in order to fundamentally solve the problem of "first-class products, second-class packaging, and third-class prices" in China, we must improve the quality of packaging, that is, while improving the internal quality of the steel barrel itself, we must also improve the appearance quality of the steel barrel. For this reason, in recent years, China's steel barrel production enterprises have gradually increased the stable speed range of frequency conversion speed regulation and step-down speed regulation, generally changing in the range of 70% to 110% of the rated speed, and have invested in steel barrel coating production lines

at present, there are various equipment used for steel barrel coating in steel barrel enterprises across the country. The spraying methods 2205 include airless spraying, electrostatic spraying, etc., and the equipment also includes imported and domestic equipment; Its drying equipment includes gas (including gas and natural gas), oil, far infrared or electric oven drying

after the steel barrel coating and drying production line of steel barrel production enterprises was completed and put into operation, most enterprises have little knowledge of safety, fire and explosion prevention of paint, gas, natural gas and so on, resulting in fire, explosion and other safety accidents from time to time. Now let's talk about the basic requirements and precautions for the safety production of the steel barrel paint drying room:

I. the danger of flammable and explosive substances in the paint drying room

the substances used in the steel barrel coating are paint and its diluent, namely solvent. Paints and commonly used solvents (except water-soluble paints and water solvents) are substances that are very prone to fire. The lower the flash point of the solvent used, the faster the volatilization rate and the easier it is to burn. The vapors volatilized by these solvents during painting can be mixed with the air in the drying room at any time and become explosive gases. If they are exposed to open flames, they are prone to explosion and combustion hazards. At present, most of the steel barrel drying uses gas and fuel oil, which are open flames, and there are hidden dangers in itself. So, how to prevent it? First of all, we need to understand the flash point, ignition point and spontaneous combustion point

the degree of combustion of common solvents in paint is determined by its flash point, spontaneous combustion point and explosion limit. Then, why is it called flash point, ignition point and spontaneous combustion point because of their different structures

1. Flash point: the solvent in the paint can volatilize into steam and run into the air. As the temperature rises, volatilization accelerates. When the mixture of volatile vapor and air can flash sparks in contact with the fire source, this short ignition process is called flashover, and the lowest temperature at which flashover occurs is called flash point. From the perspective of fire protection, the flash point of solvent is the lowest temperature that may cause a fire in the drying room. The lower the flash point, the greater the risk of fire

2. Ignition point: in the coating and drying production line, whether it is liquid paint and solvent, or gaseous gas and natural gas, all exist together with air. When it reaches a certain temperature, it will burn when it comes into contact with the fire source, and it will continue to burn after removing the fire source. At this time, the lowest temperature of combustible materials is called ignition point, also known as ignition point. The ignition point of general solvents is higher than the flash point, and the ignition point of general flammable solvents is 1~5 ℃ higher than its flash point

3. Spontaneous combustion point: under normal conditions, the slow oxidation process will occur when combustible substances are in contact with air, but the speed is very slow, and the heat released is very small. At the same time, it constantly radiates heat to the surrounding environment, and cannot emit light like combustion. If the temperature rises or other conditions change, the oxidation process will speed up, and the heat released will increase. If it cannot be completely dissipated, it will accumulate, making the temperature rise gradually. When it reaches a certain temperature, this substance will burn by itself, which is called spontaneous combustion. The lowest temperature that causes the substance to spontaneously ignite when heated is the spontaneous combustion point of the substance, also known as the spontaneous combustion temperature

at the spontaneous combustion temperature, combustible substances can burn without the action of open fire in contact with air. The spontaneous combustion point can also reduce the aircraft assembly process and reduce the manufacturing cost. It is not a fixed number. It mainly depends on the heat released during oxidation and the outward heat conduction. It can be seen that the same combustible material has different spontaneous combustion points due to different oxidation conditions and the influence of different factors

the phenomenon of spontaneous combustion shows that this substance has a greater potential fire risk than other substances. In general, the common substances that can cause spontaneous combustion are plant products, Oils and fats, coal and other chemical substances. The following is the flammability risk table of paint thinner commonly used in steel barrel spraying: