1、 Brief introduction of bag dust removal technology
Bag filter is a dry dust filtering device. After the filter material is used for a period of time, due to the effects of screening, collision, retention, diffusion and static electricity, a layer of dust is accumulated on the surface area of the filter bag. This layer of dust is called the primary layer. In the later movement process, the primary layer becomes the main filter layer of the filter material. Relying on the role of the primary layer, the filter material with large mesh can also obtain high filtration efficiency. With the accumulation of dust on the surface of the filter material, the efficiency and resistance of the dust collector increase accordingly. When the pressure difference on both sides of the filter material is very large, some fine dust particles that have been attached to the filter material will be squeezed, so that the efficiency of the dust collector decreases. In addition, the high resistance of the dust collector will significantly reduce the air volume of the dust removal system. Therefore, after the resistance of the dust collector reaches a certain value, the ash shall be removed in time. The initial layer shall not be damaged during ash removal to avoid efficiency reduction.
2、 Working principle:
The filter type dust collector refers to the equipment that the dust particles in the air flow are intercepted and collected by the filter layer when the dust containing smoke hole passes through the filter layer, so as to realize gas-solid separation. The filter dust removal device includes bag dust collector and particle layer dust collector. The former usually uses the filter bag made of organic fiber or inorganic fiber fabric as the filter layer, while the latter filter layer is mostly composed of particles with different particle sizes, such as quartz sand, river sand, ceramsite, slag, etc. With the repeated adhesion of the powder to the outer surface of the filter bag, the powder layer continues to thicken, and the resistance value of the bag filter also increases; The pulse valve diaphragm sends a command. When the left and right are submerged, the pulse valve is opened and the compressed air in the high-pressure air bag is connected. If there is no dust or it is small to a certain extent, the mechanical ash cleaning will stop working.
3、 Structural type:
1. According to the shape of the filter bag, it is divided into flat bag (trapezoidal and flat) and round bag (cylindrical).
2. According to the air inlet and outlet mode, it is divided into: lower air inlet, upper air outlet, upper air inlet, lower air outlet and DC type (only limited to plate-shaped flat bag).
3. According to the filtration mode of bag, it is divided into external filtration type and internal filtration type.
Fibers for filter materials include cotton fiber, wool fiber, synthetic fiber and glass fiber. Filter materials woven from different fibers have different properties. The commonly used filter materials are 208 or 901 polyester round flannelette, and the service temperature is generally not more than 120 ℃. The service temperature of glass fiber filter bag treated with silicone resin is generally not more than 250 ℃. Cotton wool fabric is generally suitable for non corrosive; Dusty gas with temperature below 80-90 ℃.
4、 Product advantages:
1. The dust removal efficiency is high, generally more than 99%, and the dust concentration in the gas at the outlet of the dust collector is within tens of mg / m3, which has a high classification efficiency for fine dust with submicron particle size.
2. The range of treatment air volume is wide, ranging from only 1min M3 to tens of thousands of M3. It can be used for flue gas dust removal of industrial furnaces and reduce the emission of air pollutants.
3. Simple structure and convenient maintenance and operation.
4. On the premise of ensuring the same high dust removal efficiency, the cost is lower than that of electrostatic precipitator.
5. When glass fiber, polytetrafluoroethylene, P84 and other high-temperature resistant filter materials are used, they can operate at a high temperature above 200 ℃.
6. It is insensitive to the characteristics of dust and is not affected by dust and resistance.
5、 Scope of application:
Bag type dust remover is widely used. It is generally used for flue gas treatment and dust removal system of ironmaking plant, steel-making plant, ferroalloy plant, refractory plant, foundry and power plant, waste incinerator, coal-fired boiler, fluidized bed boiler and other flue gas filtration. Asphalt concrete mixing, building materials, cement ceramics, lime, gypsum and other production sites. Aluminum electrolysis, smelting of lead, tin, zinc, copper and other rare metals, flue gas filtration, fine material recovery, liquid-solid separation. Liquid solid separation and fine material recovery in chemical industry, coke, carbon black, dyes, pharmacy, plastics and other fields. Dust treatment and purification collection in mining, grain processing, flour, electronic industry, wood processing, etc