The emission standard of bag filter
: the current standard is 30 mg, the previous emission was 50 mg, and the earlier was 100 mg.
According to many years of experience, the following points should be paid attention to:
The dust bag of the
bag dust collector must be made in accordance
with this size without deviation, otherwise there will be dust passing through the bag or the gap between the gaps, which will affect the discharge of the bag dust collector. The dust-removing cloth bag used should be coated. When welding the flower plate of the bag filter, it must be smooth and flat, there must be no leaks or gaps, and no air leakage. When designing a bag filter, the wind speed of the filter must be controlled, and the dust emission requirement of 15 milligrams can be met when the wind speed does not exceed 1 meter.
The strict emission standards make the electrostatic precipitator
change to a bag filter:
The control of sulfur dioxide in the flue gas increases the specific resistance of the dust, which makes the application of the electrostatic precipitator difficult and uneconomical. The biggest advantage of the bag filter is that the dust removal efficiency is high, and it is not affected by the change of the specific resistance of the dust.
For example: Baosteel set the internal control emission standard of bag dust collector to 35mg / m3, and Shougang recently set it to 30mg / m3. This has reached the European and American emission standards, which is consistent with the trend of foreign emission standards. It is difficult for an electrostatic precipitator to meet this requirement, while domestic dust collectors can easily reach this emission standard.
Standard emission concentration of bag filter:
Some steel mills and cement plants have transformed some electrostatic precipitators into dust-removing cloth bags. After the transformation, the dust emission concentration will be reduced, and the operating cost and maintenance workload will be lower than the electric precipitators.
However, some manufacturers of
bag dust collectors
have tested the pulse bag dust collectors for
excessive emissions in the Environmental Protection Agency. The reasons for the excessive emissions are likely to be that the filter speed of the bag dust collector
is too fast, the dust
removal cycle is too short, and the pressure of the compressed air is too high High, dust load reduction and so on.