How is the new industrial explosion-proof dust collector explosion-proof?

How to Explode the Environmental Protection Explosion-proof Dust Collector (1) Mechanism of Dust Explosion When the combustible dust burns in the air, it will release energy. The well generates a large amount of gas, and the speed of releasing the energy is the burning speed and the powder is exposed to the air. Area related. Therefore, for a powder of the same solid substance, the smaller the particle size, the larger the specific surface area, and the faster the combustion diffusion. If the particle size of this solid is very fine. So that it can be suspended, and if there is an ignition source to ignite it, a large amount of energy can be released in a very short time. These energies are too late to dissipate into the surrounding environment, causing the gas in the space to be heated and adiabatically expanded. On the other hand, when the powder is burned, a large amount of gas is generated, which causes the system to form a local high pressure, which causes explosion and propagation. This is usually It is called a dust explosion.

(2) Difference between dust explosion and combustion The combustion of large solid combustibles is carried out to the inside in a nearly parallel layer, such as combustion of coal. This release of combustion energy is relatively slow. The heat and gas generated can escape quickly. The pile-like combustion of flammable dust forms an open flame in a well ventilated condition, but in the case of poor ventilation. It can form a smokeless or flame smoldering.

There are several stages in the combustion of combustible dust: * stage, the surface powder is also heated; in the second stage, the surface layer is vaporized, and the volatile matter is overflowed; in the third stage, the volatile matter is gas-phase burned.

The explosion of ultra-fine powder is also a relatively complicated process. Since the scale of the dust cloud is generally small, and the flame propagation speed is fast, several hundred meters per second, the ignition of the fire source occurs in the dust center, less than 0.1s. The entire dust cloud can be burned in time. During this process, if the dust has burned out, a high pressure is generated, and if it is not burned, a lower pressure is generated. Whether the combustible particles can be burned depends on the size of the particles and the depth of combustion.

(3) Combustible dust classification Powders can be classified into two categories according to their flammability: one is flammable; the other is non-combustible. The classification methods and standards for combustible powders vary from country to country.

In the United States, combustible powders are classified as Class II dangerous goods, and metal powder, carbon dust, and grain dust are included in different groups. The classification method developed by the United States is classified according to the rate of increase of the measured powder in the event of a dust explosion in a standard test device, and is divided into three grades. China has not yet seen ready-made standards for the classification of combustible dust.