Air purification systems are widely used in various industries such as electronic information, semiconductors, optoelectronics, medicine and healthcare, bioengineering, aerospace, and automotive spraying. The level of purification varies significantly depending on each industry's precision and cleanliness requirements.
In dust-free workshops, the air purification process typically involves three stages of filtration: primary, medium, and high-efficiency filters. For air purification at the 100,000-class level, sub-high-efficiency filters can be used instead of high-efficiency ones. As electronic components become smaller and LCD panels advance to the eighth generation, the demand for filters in cleanroom industries continues to grow.
Differences Between Primary, Medium, and High-Efficiency Filters:
Accuracy: High-efficiency filters have the highest filtration accuracy, while primary-efficiency filters have the lowest.
Installation Positions: Filters are installed following the principle of coarse-to-fine filtration, with primary filters installed first, followed by medium-efficiency filters, and finally high-efficiency filters.
Primary Air Filters: Used for initial filtration in air conditioning systems, primarily filtering dust particles larger than 5 μm.
Medium Efficiency Filters: Serve as intermediate filters in air conditioning systems, filtering dust particles between 1 and 5 μm.
High-Efficiency Filters: Capture particulate dust and suspended solids smaller than 0.5 μm, functioning as the final stage of filtration in various systems.
Air Filters Used in Dust-Free Workshops:
Clean air entering a cleanroom must meet specific requirements for cleanliness, temperature, and humidity. Typically, the temperature is maintained between 18-28°C (unless otherwise specified), with relative humidity levels between 45% and 65%.
To ensure the comfort of personnel, the fresh air supply in a cleanroom should not be less than 15%. In purification air conditioning systems, particularly those with special climate requirements or high exhaust demands, the fresh air ratio can be increased accordingly. Filtration in an air purification system is generally divided into three stages, starting with the intake of fresh air. The first stage uses a primary efficiency filter, the second stage uses a medium or sub-high-efficiency filter, and the third stage uses a high-efficiency filter. In some cases, a fourth stage is added, incorporating an additional high-efficiency filter after the third stage. Typically, filters of different efficiencies are combined for optimal results.
For air treatment requiring a cleanliness level of 100,000 or higher, three filtration stages-primary, medium, and high-efficiency filters-are necessary. For levels at or below 100,000, such as 300,000, sub-high-efficiency filters can be used instead of high-efficiency ones.
Generally, the primary and medium-efficiency filters are integrated into the central air conditioning unit, while the high-efficiency filter is installed in the cleanroom. Clean, filtered air is then delivered through the air supply outlets into the cleanroom. The type of filters used depends on the specific requirements of each clean workshop.