Air Filter Filtration Speed

The filtration rate and surface air velocity of an air filter can be measured by surface velocity or filtration rate. Surface velocity (u): the velocity of the airflow passing through the cross-section of the air filter (m/s) u=Q/(F * 3600) Filtration rate (v): the velocity of the airflow passing through the filter material area (cm/s) v=0.028 * Q/f Q - air volume (m3/h) F - the cross-sectional area of the air filter, i.e. the windward area f - the net area of the filter material, i.e. the area occupied by the removal of adhesives, etc. The filtration rate reflects the filtration capacity of the filter material, especially the filtration performance of the filter material. The lower the filtration rate used and the lower the allowable filtration rate of the filter material, the greater the resistance of the filter material.

Filter resistance: Fibers cause airflow to bypass, resulting in minimal resistance. The sum of the resistance of countless fibers is the resistance of the air filter. The resistance of the air filter increases with the increase of air flow rate. By increasing the area of the air filter material, the relative wind speed passing through the filter material can be reduced to decrease the resistance of the air filter. The ability of an air filter to pass through air can be measured by surface air velocity or filtration rate. Filtration rate reflects the ability of the filter material to pass through, especially the filtration performance of the filter material. The lower the filtration rate used, the higher the efficiency of the air filter (because particles are more likely to stick and achieve the filtration purpose at low filtration rates); The lower the filtration rate allowed by the air filter, the greater the resistance of the filter material.

Efficient Filter Airflow Calculation Method 1

Calculated based on the national standard 484 * 484 * 220 high-efficiency filter:

The rated air volume is 1000m3/H, and the initial resistance is 200PA

1. The number of filter paper disassembly is 28 folds/10CM;

2. Calculation of filter paper filtration area: 0.475 * 0.475 * 280 * 0.2 * 2=25.27 square meters, where 0.475 is the length of the filter paper;

3. 0.475 is the width of the filter paper, 280 is the double-layer folded filter paper of 1 meter, and 0.2 is the actual height of the filter paper;

4. The cross-sectional wind speed of the filter paper is 0.011 meters per second, which means that when the cross-sectional wind speed passing through the filter paper is 0.011 meters per second, the initial resistance of the filter paper is 200PA

Efficient Filter Airflow Calculation Method 2

Prerequisite: The air volume of the high-efficiency filter is generally determined based on the air speed and size of the high-efficiency filter;

The set wind speed of a typical high-efficiency filter is between 0.3-0.6M/s, with a median value of 0.45;