Bag filter, dust collection

Bag filters have been widely used in various industrial sectors to capture non bonded and non fibrous industrial dust and volatiles, capturing dust particles up to 0.1 microns. However, when using it to treat gases containing water vapor, condensation should be avoided. Bag filter has a high purification power, even capturing fine dust with a power of over 99%, and its power ratio is high.

⑴ Gravity settling effect - When the dusty gas enters the bag filter, the large and heavy dust particles settle down under the gravity effect, which is exactly the same as the effect of the settling chamber.

⑵ Thermal motion effect - Lightweight and small dust particles (less than 1 micron) move with the airflow, very close to the airflow streamline, and can bypass fibers. But after being collided by gas molecules undergoing thermal motion (i.e. Brownian motion), they change their original direction of motion, which increases the chance of contact between dust and fibers, allowing dust to be captured. The finer the diameter of the filter fiber, the smaller the vacancy rate and the higher its capture rate, which is more conducive to dust removal.

⑶ Inertial force effect - When the air flow passes through the filter material, it can wrap around the fibers, while larger dust particles still move in the original direction under the effect of inertia force, colliding with the filter material and being captured.

⑷ Screening effect - When the particle diameter of the dust is larger than the open space between the fibers of the filter material or the gaps between the dust particles on the filter material are large, the dust is retained after the air circulation expires, which is called the screening effect. When the accumulation of dust on the filter material increases, this effect becomes more significant.

Dust removal process: Dust containing gas enters the middle box through the air inlet, enters the bag from outside, and the dust is obstructed on the surface outside the filter bag. The purified air enters the bag, then enters the upper box through the upper part of the bag, and finally is discharged through the exhaust pipe.