Analysis of the impact of changes in boiler systems on bag dust collectors
The following is an explanation from the main aspects:
1. The air volume of the supply and induced draft fans remains unchanged, but the smoke concentration at the boiler outlet changes.
Changes in smoke concentration only cause changes in the bag load of the bag dust collector, which leads to changes in cleaning frequency (automatic adjustment). If the soot concentration is high, the dust on the filter bag accumulates quickly, and the corresponding dust cleaning frequency is high. On the contrary, the dust cleaning frequency is low, but it will not cause changes in the emission concentration.
2. The amount of smoke and dust in the boiler remains unchanged, but the air volume of the supply and induced draft fans changes.
Since changes in air volume directly cause changes in filtration wind speed, which in turn causes changes in equipment resistance, it has basically no impact on dust removal efficiency. As the air volume increases, the equipment resistance increases and the induced draft fan output increases; conversely, the induced draft fan output decreases.
3. Temperature changes
If the flue gas temperature is too low, condensation may cause “bag adhesion” and shell corrosion. If the flue gas temperature is too high and exceeds the allowable temperature of the filter material, it is easy to “burn the bag” and damage the filter bag. However, if the temperature change is within the temperature range of the filter material, it will not affect the dust removal efficiency. The temperature that causes adverse consequences is at extreme temperatures (accidents/abnormal conditions), so bag dust collectors must be equipped with effective protection measures for extreme temperature control.
4. Changes in the physical and chemical composition of flue gas (or type of burning coal)
The physical and chemical composition of the flue gas has no effect on the dust removal efficiency of the bag dust collector. However, if the flue gas contains components that corrode and damage all filter materials, it will directly affect the service life of the filter materials.
5. Air flow distribution
There is no direct relationship between dust removal efficiency and air flow distribution, that is, air flow distribution does not affect dust removal efficiency. However, the local airflow distribution inside the dust collector should be as uniform as possible, and the deviation cannot be too large. Otherwise, local bag breakage will occur due to uneven local load or jet wear, which will affect the normal service life of the dust collector filter bag.
