Whether we are buying an air purifier or a fresh air system, we will hear merchants mention "HEPA filters", but many people still do not understand HEPA filters and only know that they are "advanced filters". Today, the editor of Shiyang Electromechanical will talk to you about HEPA filters and see what kind of thing they are
What is a HEPA filter?
HEPA filter, also known as HEPA high-efficiency particulate filter, stands for High efficiency particle arrest in English. Generally made of polypropylene or other composite materials. HEPA filter is internationally recognized as the best high-efficiency filter material. Initially used for nuclear energy research and protection, HEPA is now widely used in precision laboratories, pharmaceutical production, atomic research, and surgical procedures that require high cleanliness.
Working principle of HEPA filter
HEPA filters are filtered in four forms: interception, gravity, airflow, and van der Waals force
1. The interception mechanism is commonly known as a sieve, which intercepts and screens out large particles of 5 μ m and 10 μ m.
2. Under the influence of gravity, dust particles with small volume and high density decrease in velocity when passing through HEPA, and naturally settle on the HEPA filter screen like sediment settling on the riverbed.
3. Uneven weaving of the filter creates a large number of air vortices, and small particles are adsorbed onto the HEPA filter under the action of the airflow cyclone.
4. The ultrafine particles undergo Brownian motion and collide with the HEPA fiber layer, resulting in purification under the influence of van der Waals forces. Virus carriers below 0.3 μ m are purified under the influence of this force.