Causes of blockage and failure of dust collector filter bag
The blockage of filter bag mainly includes three types: dust blockage, oil mist blockage, and dew condensation bag.
Dust plugging is mainly due to the lack of clear dust, especially when the boiler is under low load, the long time no cleaning dust can also lead to the emergence of this problem. Fine dust swims on the surface of the filter bag. In the process of filtering, dust grinding against each other causes some dusts enter into fiber felt layer of filter bags, which causes the increase of inherent resistance, the uniformity of air permeability of the whole filter bag is changed, which not only causes the increase of the running resistance of the dust collector, but also changes the filter path of the flue gas, increases the filter load of the non blocked filter bag, and aggravates the deterioration of the bag condition of the dust collector;
The oil mist blockage is mainly the boiler start or low load. During the operation of fuel injection, no protection measures or protection measures of filter bags are not taken very well will lead to the increase of the inherent resistance of the filter bag. Even using of strong cleaning ash, it is difficult to solve the problem. The condensation bag is mainly under the operation of the deduster below the acid dew point and the condensate is attached to the outer surface of the filter bag. This phenomenon occurs mainly in the case of low smoke temperature or large area detonating of the boiler when the boiler starts, and the condensation bag also leads to the increase of the inherent resistance of the filter bag, and may also cause the corrosion of the acid to the filter bag at the same time.
The solutions:
Select the reasonable structure of the ash cleaning system.
Set up the reasonable cleaning pressure, the ash clearing period and the control method of dust cleaning to ensure that the dust cleaning is relatively complete and the dust clogging is avoided. It is particularly noted that excessive ash cleaning is also not advisable, because excessive ash cleaning will affect the service life and filtration performance of the dust collector filter bag.
Before the dust collector is put into operation, the filter bag should be pre coated with dust, and the dust layer can be formed on the surface of the filter bag in advance. The dust layer can block the oil mist and acid contents, avoid the direct touch between the oil mist / acid content and the filter bag surface. A certain thickness of dust layer is kept on the surface of the filter bag so as to protect the filter bag. When a large area of bursting occurs in the boiler, the humidity detector should be considered to stop or open the bypass of the dust collector when the humidity is greater than 15%.