The principle and application instructions of high efficiency filter

The principle and application instructions of high efficiency filter

The application scope of high-efficiency filters is mainly the terminal filtration of pharmaceutical, civil or industrial cleaner sites with higher requirements for cleanliness in the electronics, semiconductors, precision machinery, pharmaceutical, hospital, and food industries. As high efficiency filters are generally used as filter ends, the requirements for high efficiency filters are also the most stringent. Of course, additional "care" is required.

The most fundamental and simple way to extend the life of an efficient filter is to keep dust out of the prefilter. In other words, ensure that the air flow exposed to the high-efficiency filter is the air filtered by the pre-filter, rough filter, and medium filter. The air at this time should reach 99. 95 % of the dust is smaller and less polluting.

It should be noted here that replacing pre-filters generally does not require a shutdown or other normal work schedules and arrangements. After installation, no debugging is required to ensure the normal operation of air conditioning new air equipment. So experienced customers focus on prefilters. For highly clean areas such as the 10000-grade and 100,000-grade clean plants or operating rooms, pre-filtration can use F8 filtration(95 % colorimetric method).

In this way, the useful life of the terminal efficient filter can generally reach 5 years. In foreign projects and new projects in China. The F8 medium effect filter is the most common pre-filter in the non-uniform flow cleaning room. For chip plants with clean plants of Class 100, Level 10 or higher, the common efficiency level of pre-filters is H10(MPPS 85 %), and many new projects simply use HEPA(for 0). The filtration efficiency of 37m particles ≥ 99. 97 %). In the past clean room air-conditioning system design in China, the common configuration of filters is: rough effect → medium effect → high efficiency. At that time, the service life of the terminal efficient filter was only 1-3 years, and the worst was only a few months. It can be seen that the prefiltration efficiency determines the service life of the terminal filter.

In some cases, the regulations for the use of high-efficiency filters are not due to the consideration of resistance, but other factors. If hydrofluoric acid is present in the factory building and the air-conditioning in the workshop is not a full-wind system, the fiberglass filter paper of high-efficiency filters will be corroded by the wind. For safety, efficient filters must be replaced regularly. At present, some Grade III A hospitals and pharmaceutical manufacturers in China will actively replace high-efficiency filters after the rainy season each year. The main purpose is to prevent any possible mold pollution on the filters. In some countries, level III A hospitals, biological laboratories of manufacturing laboratories and laboratories dealing with dangerous goods will use new efficient filters to ensure safety and reliability before embarking on a new vital subject.