What is the role of the air filter used in the cleanroom of the purification workshop? What are the filter classifications?

Purification workshop clean room useAir FilterWhat is the role of the filter? What are the filter classifications?

Previously, I took you to introduce several common cleanroom materials, facilities, equipment, today we are talking about another key equipment together, as the purification of air plays an important role, that is, theAir FilterAs the name implies, air filter is to filter dirty particles and substances in the air, so that the air is processed to the degree of cleanliness we want, but according to the different levels of purification, the degree of purification is different, the selection of appropriate air filters, in order to make it play its due role, to achieve satisfactory results.

First of all, we first elaborate the principle of the role of the filter, that is, the five effects. As we all know, the dust particles in the air are very small, it is difficult to capture with the naked eye, it is necessary to use special materials, so that the dust particles in the passage of the dust particles are intercepted, captured.

1, the role of interception; that is, the fiber layer, the fiber intricate arrangement, the formation of many grids, when the dust particles movement to the fiber surface, due to the intricate fiber gap is less than or equal to the radius of the dust particles, that is, be intercepted.

2, Brownian motion; that is, suspended in liquid or gas particles do not stop moving, which makes the particles have a greater chance of movement to the surface of the fiber and deposited.

3, gravity; relatively large particles in the movement process, due to the effect of gravity settled on the surface of the filter media.

4, electrostatic effect; we all know that static electricity can adsorb dust, the same reason, fibers and dust particles may be charged, and the electrostatic effect.

5, inertia effect; airflow through the fiber layer, due to inertia, particles are too late with the flow line around the fiber, collision that is intercepted.

Second, the classification of the filter

As early as in 92 and 93 years, China has promulgated the two standards of "High Efficiency Air Filter" and "Air Filter", and now we categorize the filters into primary filters, intermediate filters, high and middle efficiency filters, sub-high efficiency filters, high-efficiency filters, and ultra-high efficiency filters.

1, the primary filter is also called coarse filter, filter particle size ≥ 5 um, filtration efficiency in 20%-80%, the initial resistance ≤ 50 pa. Generally used plate, bag, folding, winding, filter material is mostly non-woven fabrics, metal mesh and so on.

2, medium-effect filter, filter particle size ≥ 1 um, filtration efficiency in 20%-70%, initial resistance ≤ 80 pa, generally using bag type, it is mainly used as a high-efficiency filtration before the pre-filtration, in order to extend the service life of the high-efficiency filter. It mainly filters new air and return air.

3、High-medium-efficiency filter, filtration particle size ≥ 1 um, filtration efficiency in 70%-90%, initial resistance ≤ 100 pa, it can be used as a general purification of the end of the filter, purification is not high, the requirements are not strict.

4, sub-high efficiency filter, filter particle size ≥ 0.5 um, filtration efficiency ≥ 95%, initial resistance ≤ 120 pa. can also be used as a purification level is not high end filter.

5, high-efficiency filters, high-efficiency filters are more common, used for purification workshop more, filter particle size ≥ 0.3 um, filtration efficiency ≥ 99.99%, initial resistance ≤ 220 pa.

6, ultra-high efficiency filter, filter particle size ≥ 0.1 um, filtration efficiency ≥ 99.999%, initial resistance ≤ 280 pa, ultra-high-efficiency filters can be used in the purification level of the requirements of the clean room is very high. Such as microelectronics industry.

Third, high-efficiency air supply outlet

1, commonly used high-efficiency air intake GB-02, GB-01, GB-03, so what do several national standard represent? The classic model of our high efficiency filter is GB-01, that is, 484 series, with a filter section of 484 mm.484 mm, GB-02 filter section 320 mm320 mm. GB-03 filter section 630 mm*630 mm. of course, with the continuous development of science and technology, its specifications and dimensions are constantly changing.

2, the following we summarize, different specifications of high-efficiency air supply outlet connected to the duct, the roof opening size are how much, can be used as a construction reference.GB-02 high-efficiency air supply outlet high-efficiency size 320320 mm, usually with 200 mm diameter air ducts200 mm, color steel plate top opening 370370 mm, GB-01 HEPA High Efficiency Size 484484 mm, usually 320 mm in diameter for air ducts.200 mm, color steel plate top opening 540540 mm, GB-03 high efficiency air supply outlet high efficiency size 630630 mm, usually 320 mm in diameter for air ducts.250 mm, color steel plate top opening 680*680 mm.

3, but in the actual project, such as purification level is slightly higher, 10,000 or 1,000, the room area is limited, so we need a large amount of air supply to ensure that the number of times the room ventilation, however, the arrangement of many high-efficiency lead to the top plate all high-efficiency air supply, full cloth rate is very high, so that the top plate load-bearing and installation of lamps have a certain impact, then we need to change the amount of air is slightly larger than a reasonable arrangement of high-efficiency air supply, according to the Need to customize non-standard high-efficiency air supply outlet, so that its individual air volume of 2000 m 3 / h, or 3000 m 3 / h, or higher. Such as 2000 m 3/h high-efficiency air supply outlet, can be two GB-01 model synthesized into a size size, that is, high-efficiency size 968 * 484 mm.