Views: 0 Author: Site Editor Publish Time: 2020-11-20 Origin: Site
Medium efficiency filterFiltering principle:
1. Intercept the dust particles in the air, and move with the airflow in inertial motion or irregular Brownian motion or under the action of a certain field force. When the motion of the particles hits other objects, the van der Waals forces (which are molecules and molecules, The force between the molecular group and the molecular group) makes the particles stick to the fiber surface. The dust entering the filter medium has more chances to hit the medium, and it will be stuck when it hits the medium. Smaller dusts collide with each other to form larger particles and settle, and the particle concentration of 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: Particle dust moves inertially in the airflow. When it encounters disorderly arranged fibers, the airflow changes direction, and the particles deviate from the direction due to inertia and hit the fibers to be bonded. The larger the particle, the easier it is to hit, and the better the effect. Small dust particles make irregular Brownian motion. The smaller the particles, the more violent the irregular movement, the more chances of hitting obstacles, and the better the filtering effect. The particles smaller than 0.1 microns in the air mainly make Brownian motion, the particles are small and the filtering effect is good. Particles larger than 0.3 microns mainly make inertial motion, the larger the particle, the higher the efficiency. Diffusion and inertia are not obvious and particles are the most difficult to filter out. When measuring the performance of high-efficiency filters, people often specify the dust efficiency value that is the most difficult to measure.
3. Electrostatic effect For some reason, fibers and particles may be charged and produce electrostatic effect. The filtering effect of electrostatically charged filter materials can be significantly improved. Reason: Static electricity makes the dust change its trajectory and hit obstacles, and static electricity makes the dust stick to the medium more firmly. The material that can charge static electricity for a long time is also called \"electret\" material. After the material is charged with static electricity, the resistance remains unchanged, and the filtering effect will be significantly improved. Static electricity does not play a decisive role in the filtering effect, only an auxiliary role.
4. Chemical filter \"Chemical filter mainly selectively adsorb harmful gas molecules. There are a large number of invisible micropores in the activated carbon material and a large adsorption area. In activated carbon the size of rice grains, the area of the micropores is more than ten square meters. After the free molecules contact the activated carbon, they condense into liquid in the micropores and stay in the micropores due to the capillary principle, and some are integrated with the material. The adsorption without obvious chemical reaction is called physical adsorption.
someMedium efficiency filterThe activated carbon is processed, and the adsorbed particles react with the material to generate solid matter or harmless gas, which is called Huai Xue adsorption. The adsorption capacity of the activated carbon material is constantly weakened during use, and when it weakens to a certain level, the filter will be scrapped. If it is only physical adsorption, heating or steam fumigation can remove harmful gases from activated carbon and regenerate activated carbon.