Six dust removal mechanisms work together to complete the filtration process with a bag filter
The dust removal mechanism of the bag filter is complex, including the sedimentation mechanism of dust particles such as inertial collision, interception, diffusion, gravity and electrostatic force, and the sedimentation and trapping of dust particles in dust-containing gas on the filter material is formed by the joint action of various mechanisms.
The dust removal mechanism of the filter bag mainly includes six different mechanisms:
Sieve effect: the mesh size of the filter bag filter material is generally relatively small, about 30μm, and the dust particles with relatively large size are left on the outer surface of the filter bag when they pass through the outer surface of the filter material during the filtration process, which is called sieving effect.
Inertial collision: As shown in the above figure, the dust-containing air flow through the filter material at a uniform speed in the filtration process, the dust particles with relatively small particle size flow through the filter material with the air, and the dust particles with large particle size hit the fiber of the filter material due to their own inertia, and this dust removal mechanism is called doing
Inertial collision: This dust removal mechanism is mainly used to remove the dust with relatively large particles, and the filtration gas velocity affects the inertia of the dust particles themselves, and an appropriate increase in the filtration gas velocity can enhance the inertial collision effect and improve the dust removal efficiency.
Interception: When the dust-containing gas flows through the fibers on the surface of the filter bag, the dust particles with smaller particle size circulate the filter bag with the filter airflow, and the dust particles with large particle size are in contact with the fibers on the surface of the filter bag and are trapped.
Diffusion: In the filtration process, some dust particles make irregular Brownian motion due to the extremely small particle size, and they will be exposed to the fibers and captured when they carry out irregular motion, and the dust removal mechanism caused by Brownian motion is called diffusion.
Electrostatic action: When the filter air flows through the filter bag, the dust particles and the fibers on the surface of the filter bag will rub against each other so that the dust particles and fibers are charged, and part of the charged dust particles are captured by the charged fibers.
Gravity sedimentation: When the filter wind speed of the dust collector is set to a low level, when the dust-containing air flow enters the dust collector, the dust with relatively large particles and some dust particles with relatively large density directly settle down and enter the ash hopper under the action of gravity.
Through the introduction of these six main dust removal mechanisms, it can be seen that the filtration process of bag filter dust removal does not play a single role in the dust removal process, and usually several dust removal mechanisms work together to complete the filtration process.