1. The difference between dust explosion and combustion is that the combustion of large solid fuel is pushed along the parallel layer, such as the combustion of coal. This release of combustion energy is relatively slow. The heat generated by the gas and can quickly escape. Combustible dust in the form of combustion, in the case of good ventilation to form open flame combustion, and in the case of poor ventilation.
2, after dust explosion occurs, often produce two explosions, this is because in the first explosion, there are a lot of dust deposited together, its concentration exceeds the upper limit of dust explosion value and not explode. However, when the first explosion shock waves formed or deposited dust to be raised, in the air mixed with the air in the dust explosion concentration range, it may then have two times of explosive. The second explosion often causes much more serious damage than the first explosion.
3, the mechanism of dust explosion, combustible dust combustion in the air will release energy, the well produces a large amount of gas, and the speed of release of energy, the speed of combustion is related to the area of the powder exposed to the air. Therefore, for the same solid material powder, the smaller the particle size, the greater the specific surface area, the faster the combustion diffusion. If the solid has a very fine particle size. It can be suspended, and once a fire source ignites it, a large amount of energy can be released in a very short period of time. These energy not dissipated into the surrounding environment, the space within the gas by heating and adiabatic expansion, and on the other hand, the powder combustion produces large amounts of gas, will make the system form local high pressure, resulting in explosion and propagation, which is usually called the dust explosion.
4, dust explosion is much more complicated than the combustible material and combustible gas, combustible dust suspended in the air of dust cloud in the explosion concentration range, the point source function, and the contact portion of dust ignition was first ignited and the formation of a small fireball. Under the action of the heat released by the small fireball, the dust near the ground is heated, the temperature rises, and the ignition and combustion phenomenon occurs, so that the fireball will expand rapidly and form dust explosion.
2 how to prevent dust explosion of dust collector?
A smokeless or flame invisible flame can be formed. How to prevent dust explosion of dust collector?
1. the design of dust collector when the ash hopper wall angle is more than 7002, welding formed in two bevel angle on bucket slip plate, to avoid the 9002 angle ash.
2. electrostatic precipitator is used to prevent the accumulation of electrostatic sparks and ignite the pulverized coal.
3. using gravity relief valve, when the critical pressure is exceeded, the pressure relief valve is opened, so that the explosion consequences can be limited to the minimum.
4. there is no smaller inclined ash deposit plane in the body, and the inner support is designed with the angle steel.
5. with the thermometer, when the thermometer exceeds the critical temperature, the signal will be sent to the computer console, the console will send sound and light alarm signal, notify the post processing immediately.