working principle: ⑴ Gravity settling effect - When the dusty gas enters the bag filter, the large and heavy dust particles settle down under the action of gravity, which is the same as the effect of the settling chamber. ⑵ Screening effect - When the particle diameter of dust is larger than the gaps between the fibers of the filter material or the gaps between dust particles on the filter material, the dust is retained when the airflow passes through, which is called screening effect. When the accumulation of dust on the filter material increases, this effect becomes more significant. ⑶ Inertial force effect - When the airflow passes through the filter material, it can pass around the fibers, but larger dust particles still move in the original direction under the action of inertia force, and then collide with the filter material and are captured. ⑷ 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. When the diameter of the filter fiber is finer, the porosity is smaller, and the capture rate is higher, it is more conducive to dust removal. Bag filters have been widely used in various industrial sectors for a long time, 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 filters have high purification efficiency, even capturing fine dust with an efficiency of over 99%, and their efficiency is relatively stable. |