What is the range of HEPA filters used?
Hepa filter can be widely used in optical electronics, optics, LED liquid crystal manufacturing, DC, instrumentation, circuit boards, biomedicine, precision instruments, beverage and food, PCB printing and other industries of dust-free purification workshop air supply end.
Hepa filter is mainly used for air suspended particles below 0.5μm, as the open end filtration of various filtration systems;
Use of high efficiency filter:
1. High-grade purification equipment
2, purification system end filter
3. Local purification equipment and clean workshop
4, suitable for hospitals, electronics, food, precision machinery, semiconductor and other need high cleanliness of the occasion of filtration. The filtration efficiency of HEPA filter for particles ≥0.3μm is more than 99.99%.
Hepa filter manufacturers mainly filter material for filter paper, filter paper is generally divided into glass fiber filter paper and chemical fiber filter paper. And there are two kinds of domestic filter paper and imported filter paper, but no matter which kind, should have good qualified filtration performance, but in order to save costs, fake filter element will use very poor quality filter paper, this filter paper can not prevent the dust in the air from entering the engine during the working process. Because of its extremely low HEPA filter quality often causes the engine to fail to work properly.
According to the structure of HEPA filter can be divided into: partition HEPA filter, no partition HEPA filter, combined HEPA filter.
How to judge the quality of HEPA filter paper?
There are several methods to detect the filter paper of high efficiency filter, such as oil mist method, this technology originated in Germany, is a technology to judge the filter efficiency of oil mist particles by the turbidity difference of the gas sample before and after the filter.
When detecting HEPA filter, oil mist method is easy to cause damage to the filter, and can not directly read the value, resulting in a waste of time. There is also a detection method called sodium flame method, which originated in England and is one of the current national standard methods.
Its test dust source is multi-dispersed phase sodium chloride salt spray. “It is a technology to make determination by detecting the speed of salt water under the stirring of compressed air. Since tiny salt crystal particles are formed after drying and enter the air duct, the salt mist samples are taken before and after the filter. And to determine the filter efficiency of salt spray filtering effect of a technology.
In addition, there is another detection technology called isofluorescence method, and then measure the fluorescence brightness of sodium fluorescein aqueous solution under specific conditions, the brightness reflects the weight of dust, thus calculating the filtration of HEPA filter.