Characteristics of bag filter in asphalt concrete mixing plant

Characteristics of bag-type dust collector in asphalt concrete mixing plant:

1, bag type dust collector has high dust removal efficiency, dust removal efficiency can reach more than 99%, for more than 0.5μm of dust removal rate is above 99.99%;

2, wide range of application, can be used for different types of asphalt mixing equipment, processing air volume can be large or small;

3, strong adaptability, flexible use, flexible operation, the selection of different functions of the filter bag, can be used for different kinds of fuel such as diesel, heavy oil, impurity oil and coal, and the inlet gas dust concentration changes greatly, has little impact on the dust removal efficiency;

4. Compared with wet dust removal equipment, dust can be recycled according to the size of classification, there is no sludge treatment problem or secondary pollution;

5. Compared with other precipitators, bag type dust collector has no complicated auxiliary equipment and technical requirements, low cost and operating cost, and long service life. Therefore, bag dust collector is the most commonly used asphalt mixing equipment, but also the most ideal dust removal system.

Bag-type dust collector used in asphalt concrete mixing equipment is mainly composed of box, baffle plate, filter bag, filter bag skeleton, pipe, blowout device, differential pressure meter, spiral conveyor and controller, etc. Bag filter in the work, in the role of induced draft fan suction, the smoke gas into the box body, under the baffle plate cutting block is separately flue gas flow, dust from each filter bag outside into the gas inside the filter pocket, the filter bag of screening, grille, impact, interception, diffusion and electrostatic attraction, the dust attached with a gap between the filter cloth, dust separation from flue gas. With the accumulation of dust on the filter bag, a certain thickness of dust layer is formed, which reduces the breathability of the filter cloth and prevents the normal work of the dust collector. Therefore, the dust accumulation on the filter bag must be removed frequently and timely in the work of the bag filter.

Most of the cleaning methods of bag dust collector are jet blowing. Blowout methods include pulse valve high-pressure blowout and atmospheric blowback. Pulse valve high pressure blowout means that the controller controls the pulse valve at regular intervals above the filter bag and the flue gas in reverse injection of high pressure small compressed air, so that the filter bag produces jitter and vibration, the dust on the bag will fall to the bottom of the box, and then through the spiral conveyor located at the bottom of the box sent to the outside of the box. The principle of atmospheric backblowing is similar, only it uses not compressed air, is the use of induced draft fan formed in the bag inside and outside the pressure difference, the use of the negative pressure generated by the atmosphere to clean the bag in batches. In order to ensure the filtering effect of the filter bag, a certain pressure difference must be maintained between the soot containing gas and the filtered purified gas, so the differential pressure meter is installed on the bag filter. If the pressure difference is too large, it indicates that the filter bag accumulates too much dust and the filtration resistance is too large. Small pressure difference indicates that the filter bag has been damaged.