Air filter related principle

- Nov 09, 2018-


The dust particles in the air move with inertial motion or random Brownian motion of the airflow or by some field force. When the particle motion hits other objects, the van der Waals force exists between the objects (molecular and molecular, molecular group and The force between the molecular groups causes the particles to stick to the surface of the fiber. The dust entering the filter media has a greater chance of hitting the media, and it will stick if it hits the media. The smaller dust collides with each other to form larger particles and settle, and the particle concentration of the dust in the air is relatively stable. The fading of the interior and walls is for this reason.

It is wrong to treat the fiber filter like a sieve.

2. Inertia and diffusion

The particulate dust moves in inertia in the airflow. When encountering the fibers arranged in disorder, the airflow changes direction, and the particles are bound by the inertia deviating from the direction and hitting the fibers. The larger the particle, the easier it is to impact, and the better the effect.

Small particle dust is used for random Brownian motion. The smaller the particles, the more intense the irregular movements, the more chances of hitting the obstacles and the better the filtering effect. Particles smaller than 0.1 micron in the air are mainly used for Brownian motion, and the particles are small and the filtering effect is good. Particles larger than 0.3 microns are mainly used for inertial motion, and the larger the particles, the higher the efficiency. It is not obvious that the diffusion and inertia are the most difficult to filter out. When measuring high performance filter performance, people

It is often specified to measure the dust efficiency value that is the most difficult to measure.