We should pay attention to the operating procedures and usage issues of dust removal equipment when using it. Each dust removal equipment has its own set of usage methods and operating standards, and we must always keep these standards in mind in order to protect ourselves and the equipment well. And in the event of an accident, we can minimize the risk factor and degree of damage as much as possible.
The working mechanism of a bag filter is that the dusty flue gas passes through the filter material, and the dust particles are filtered out. The filter material mainly captures coarse dust by inertial collision, while capturing fine dust mainly relies on diffusion and screening. The dust layer of the filter material also has a filtering effect.
It is quite important to control the speed of flue gas passing through the filter material (known as filtration speed) during the operation of the bag filter. Generally, the filtration speed is 0.5-2m/min, and for particles larger than 0.1 μ m, the efficiency can reach over . The equipment resistance loss is about 980-I470Pa.
Special attention should be paid to the use of bag dust removal equipment: for powders of the same solid substance, the smaller the particle size, the larger the specific surface area, and the faster the combustion and diffusion. If the particle size of this solid is so fine that it can be suspended, once an ignition source ignites it, a large amount of energy can be released within a certain period of time. When burning dust in the air, it releases energy and produces a large amount of gas, and the speed of energy release, that is, the burning speed, is related to the area of the powder exposed to the air. These energies cannot be dissipated into the surrounding environment in time, causing the gas in the space to be heated and expand adiabatically. On the other hand, when the powder burns, a large amount of gas is produced, which can cause the system to form local high pressure, resulting in explosion and propagation, which is commonly known as dust explosion.
At that time, the usage rate of bag filters accounted for 80% of the market. When using dust collectors, the dust removal efficiency of bag filters is an important factor affecting the performance of dust collectors and also affecting people's choice of dust collectors. Therefore, the dust removal efficiency of bag filters should be improved from different aspects.
The classification power of the same bag filter varies under different working conditions. The dust removal power of a new bag filter is low, while the dust removal power of a bag filter after dust accumulation is high. After dust cleaning, the dust collection power of the bag filter decreases slightly. It can be seen that the dust layer on the surface of the bag filter plays a role in collecting dust, usually referred to as the secondary filtration layer, while the bag filter only supports the dust layer. So the intensity of dust removal should be appropriate, and a thick dust layer should be retained to prevent a decrease in dust removal power.
2. The bag filter should strengthen its sealing. The dust removal system mainly includes the bag filter body and other equipment of the dust collection system, such as star shaped unloaders, inlet and outlet valves, conveying equipment and pipelines, inspection doors, etc. Strengthen the sealing of inspection holes and doors, and use double-layer doors for inspection. The sealing around the door should be made of heat-resistant silicone rubber. The sealing of conveying equipment should also be strengthened for maintenance to reduce air leakage. All connections of the shell must be continuously welded without any gaps or openings (such as air leakage at door holes and dust removal areas). Therefore, it is necessary to strengthen the inspection and spot check of the dust collection system, inspect the integrity and sealing of the dust collector air ducts, shells, upper flower plates, and other parts. If worn parts are found, they should be repaired and welded in a timely manner.
3. For particles with a diameter of 0.2-0.4 μ m, the dust collection power of the bag filter is usually low in all three working conditions, because the planned dust particles are located in the working principle of the bag filter; Obstructive effect; And "; Dispersive effect "; Therefore, dust within the 0.2-0.4 μ m range is difficult to capture due to its lower limit.
