What impact does the change of boiler combustion conditions have on bag filter

The coal type of coal-fired power plants is relatively stable, but it is inevitable that the coal type or coal quality will change; the boiler system is a system that changes and adjusts frequently, so the physical and chemical properties of the flue gas, the concentration of smoke, the temperature and other parameters coming out of the boiler cannot be guaranteed not to change. This series of changes will cause significantly different changes for different dust collectors.

The following is a comparison from several main aspects:

1. The air volume of the fans remains unchanged, and the smoke concentration at the boiler outlet changes

The change in smoke concentration only causes the change in the load of the bag filter bag of the bag filter, which leads to a change in the cleaning frequency (automatic adjustment). The dust accumulation speed on the filter bag is fast when the smoke concentration is high, and the corresponding cleaning frequency is high, and vice versa, the cleaning frequency is low, and the emission concentration will not change.

2. The amount of boiler smoke remains unchanged, and the air volume of the fan changes

Because the change in air volume directly causes the change in the filtration wind speed, it causes the change in equipment resistance, and has basically no effect on the dust removal efficiency. The increase in air volume increases the equipment resistance and the output of the induced draft fan increases; conversely, the output of the induced draft fan decreases.

3. Temperature changes

If the flue gas temperature is too low, condensation may cause "bag sticking" and shell corrosion. If the flue gas temperature is too high and exceeds the filter material's allowable temperature, it is easy to "burn the bag" and damage the filter bag. However, if the temperature change is within the filter material's tolerance temperature range, it will not affect the dust removal efficiency. The temperature that causes adverse consequences is at extreme temperatures (accidents/abnormal conditions), so effective protection measures for extreme temperature control must be provided for bag filters.

4. Changes in flue gas physicochemical composition (or type of coal burned)

The physicochemical composition of flue gas has no effect on the dust removal efficiency of bag filters. However, if the flue gas contains components that corrode all filter materials, it will directly affect the service life of the filter materials.

5. Airflow distribution

The dust removal efficiency has no direct relationship with the airflow distribution, that is, the airflow distribution does not affect the dust removal efficiency. However, the local airflow distribution inside the dust collector should be as uniform as possible and should not deviate too much, otherwise it will cause local bag breakage due to uneven local load or jet wear, affecting the normal service life of the dust collector filter bag.

6. Air preheater and system pipeline leakage

For filter materials with poor oxygen resistance, the life of the bag will be affected, such as RYTON filter materials, but the dust removal efficiency will not be affected. The increase in air volume mixed into the cold air system leads to an increase in system resistance.