How to ensure the effectiveness of dust bag use
Aug 11, 2022Dust bag will directly affect the efficiency of dust removal, how to use and maintain the dust bag is very important. The temperature is too high or too low in the corresponding case will also bring impact to the dust bag, dust bag usually in use to prevent the internal gas cooling to below the dew point, especially in the negative pressure working bag dust collector. As air often leaks in from its shell, causing the temperature of the bag chamber to decrease, making the internal gas temperature below the dew point, the dust bag will be subject to moisture, the dust will not show fluffy, but stick to the dust bag, blocking the fabric holes, causing the dust cleaning failure, the pressure drop of the dust collector will become large, too much pressure can not continue to run, part of it will also produce dust bag paste bag can not remove dust. To prevent dew, it is necessary to keep the temperature of the gas in the dust collector and its system everywhere higher than its dew point 25~35℃ (such as the dew point temperature of the kiln mill machine 58℃, the running temperature should be above 90℃) to ensure the good use of dust bag.
Take appropriate heating measures. Such as setting far-infrared electric heater, electric heater in the dust collector, or adding heater in the bag chamber, which can appropriately increase the flue gas temperature of the main machine and strengthen the temperature monitoring of the dust collector and dust removal system in order to grasp the use conditions of the bag dust collector and prevent the generation of condensation.
Reduce air leakage. The leakage of air from some crevices of dust collector body, the leakage of dust bag body should be controlled below 3.5%, the leakage of air from process equipment in dust collector system such as the airtight ash discharge valve at the discharge port of ball mill, the leakage of airtight ash discharge valve under dust collector, the pipe flange connection, etc.. These are often overlooked by maintenance managers, thus, increasing the amount of unwanted air leakage and deteriorating the operating conditions of the baghouse.
Additional raw material pile shed. In the cement production of various raw materials, fuel and mixed materials with different water content, if placed in a fixed pile shed to prevent rain can greatly reduce the water content of the material, which is a measure to reduce the material moisture, in China's southern cement plant this situation is more common, but some of the material pile shed is too small, some are not, therefore, to the use of the bag filter caused by the corresponding difficulties.
Do a good job of insulation and rainproofing of dust collector, pipelines and other relevant places, practice has proved that good insulation measures can make the difference between the inlet and outlet temperature of bag filter very small, which is a measure to prevent condensation, dust-containing gas should be evenly distributed in the dust collector to prevent the emergence of vortex in the corners to make the amount of gas passing here reduce the formation of local low temperature and produce condensation problems.
Notes on the use of dust bag
1. New process old bags should not be mixed, to avoid damage time is different to affect the normal work of dust removal equipment.
2. The aging of the cloth bag. Mainly due to the following reasons, shall conduct a cause investigation, take elimination measures and replace the dust filter bag. ① hardening and shrinkage due to abnormal high temperature; ② contact reaction with acid, alkali or organic solvent vapor; ③ reaction with moisture.
3. The filter cloth should not be hung too loose or too tight, too loose easy to accumulate dust, too tight easy to pull bad.
4. The replacement of the bag, first blow clean with compressed air, and then check whether there are holes, there are holes repaired and left for replacement. Such as dust glued bags, rinse with water, cool and dry, and then set aside for replacement.
5. The dust bag blockage. Bag blockage occurs when the resistance increases, can be expressed by the increase in the reading of the differential pressure meter. Bag clogging is the main cause of bag wear, perforation, shedding and other phenomena. Causes of dust bag blockage, according to the table for inspection and maintenance. Generally take the following measures: ① temporarily strengthen the dust cleaning to eliminate the blockage of bags; ② partial or full replacement of bags; ③ adjust the installation and operating conditions.