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中文 (中国)For the clean room in operation, the end of the high efficiency filter is not high value, all add up to two hours may not be the user’s output, but the risk of replacement filters and overhead costs will be high.
Replace the filter to stop production, loss of production can only be calculated by the owners themselves, this loss is certainly higher than the cost of spare parts filter. Replacing the filter is a very careful operation, and nothing in the clean room can withstand the rigors of an obscure device. The damage may be higher than the cost of the entire filter. After the filter to be replaced by professionals to detect, and sometimes also on the air conditioning system debugging, and then also after a period of trial operation. Testing, commissioning, commissioning, three costs added together, may be comparable with the filter price. Smart owners always want to extend the useful life of the filter as much as possible, not to save the filter money, they want to avoid the trouble of replacing the filter.
To give an extreme example, contemporary chip factory clean room at the end of high efficiency filter design life of “life”, namely: put into operation will never use high efficiency filter heart. The kind of plant technology with each passing day, a new project put into operation 5 to 7 years behind, high efficiency filter “life” is 7 years, in order to insurance, designers will filter design life of 10 to 20 years .
Efficient filter too much resistance to fouling, large to affect the normal air supply, the efficient filter on the scrapped. Increasing the filtration area of the HEPA filter or increasing the number of filters increases the service life of the filter. But those practices of the game space is not, you can not infinitely increase the filter area.
To extend the useful life of high efficiency filter, the most fundamental way is to block the dust in the pre-filter. Replacement of the pre-filter generally do not need to stop production, no debugging, so experienced owners will pay attention and money spent on the pre-filter.
For the 10000 and 100000-class clean room, pre-filter can be used F8 filter (colorimetric 95%), so that the end of the high efficiency filter life of up to 5 years. F8 filters are the most common pre-filters for non-uniform flow cleanrooms in both foreign and domestic new projects.
For the clean room of chip factory 100, 10 or higher, the pre-filter efficiency level is H10 (MPPS 85%), many new projects simply choose HEPA (0.3μm particle efficiency ≥ 99.97%). Designers claim to ensure that the end of high-performance filter to use “life”, the method just the case.
In the past, the domestic clean room air conditioning system design, filter common configuration: rough effect → efficiency → efficiency. At that time the end of the life of efficient filters is only 1 to 3 years, the worst also a few months.
In some cases, the useful life of a high efficiency filter is not dictated by resistance, but rather by other factors. If the plant has hydrofluoric acid, and the workshop air conditioning is not a new air system, high efficiency filter in the glass fiber filter paper will be the return air corrosion, in order to be safe, regular replacement of high efficiency filter. Some pockets of the pharmaceutical factory, the annual after the rainy season to replace the high efficiency filter, in order to prevent any possible mold contamination of the filter. In some laboratories dealing with biological laboratories and dangerous goods, a new high efficiency filter is required by the supervisor to be reliable before a new and important task is taken.