Junior High Hepa Filter FAQ

Junior High Hepa Filter FAQ

1. What are the actual and nominal dimensions of a barrier-free HEPA filter?

 Answer: the reason why there is a distinction between the actual size and the nominal size of the separator is that the nominal size includes the outer frame and the filter material, while the actual size generally removes the outer frame, only the width, height, depth and area of the filter media are calculated.

2. What are the differences between clapboard and non-clapboard efficient filters?

 Answer: the high efficiency filter may divide into: has the partition board high efficiency and does not have the partition board high efficiency.

    The utility model relates to a high-efficiency filter with a partition plate, which is made of ultrafine glass fiber as a filter material, plastic board paper and aluminum platinum as a partition plate, and is combined with a wooden frame or an aluminum alloy frame glue, widely used with a variety of local purification equipment and clean plant.

   Non-baffle high-efficiency filter is made of ultra-fine glass fiber as filter material, hot melt adhesive as separator, and various kinds of outer frame assembly, the outer frame is beautiful, compared with the baffle high-efficiency filter, under the same air volume, the utility model has the advantages of small volume, light weight, compact structure, reliable performance, etc. .

3. Standard folding, folding height, and formula conversion of filter media with and without baffles for high efficiency filters?

 Answer: the folding height of filter paper with bulkhead is about 30mm ~ 34mm shorter than the height of nominal size. The folding number is mainly determined by the degree of tightness of the filter paper and the filter paper assembled with the bulkhead paper. The Radian of the bulkhead paper is calculated according to the standard, generally for 4 mm, less than 4 mm, there is the number of separators on the number of separators, in addition to the loose assembly, the result is counterproductive, there are separators on the number of separators, and the number of filter paper without separators fold, mainly by the filter paper fold high, and the degree of closeness of the filter paper.

4. What are the similarities and differences between PP HEPA and fiberglass HEPA? 

A: the comparison table of“PP HEPA” and glass fiber“HEPA” is as follows: PPHEPA glass fiber HEPA skin irritation no fiber shedding no fiber and shedding fiber has serious harm to the human body filtering effect good good resistance to wind (about twice as much as PPHEPA)

5. What are junior, middle, high school, sub-high, efficient filters? 

Answer: the initial effect filter is suitable for the air conditioning system pre-filtration, mainly used for filtering more than 5um dust particles. There are three types of primary filter (folding, plate, bag) . The outer frame                   material has the paper frame, the aluminum frame, the galvanized frame, the filter material has the non-woven cloth, the nylon net, the active carbon filter material, the metal hole net and so on.

Rfilter high efficiency filter is mainly divided into two types of filters with and without baffles.

6.Classification and performance comparison of primary, intermediate and high efficiency filters? 

Answer: for particle size greater than 5.0 um particles of atmospheric dust counting efficiency greater than or equal to 20% and less than 80% of the filter called the initial effect filter.

    For particles larger than 1.0 um particle count efficiency of more than 20% and less than 70% of the filter is called the intermediate effect filter.

   A filter with an efficiency of 99.99% or more for counting atmospheric dust particles larger than 0.3 um is called an efficient filter.

7. The function and principle of fan filter unit FFU?

 Answer: FFU Laminar Air Supply Unit can be used in modular connection, making FFU widely used in clean room, clean bench, clean production line, assembled clean room and laminar hood applications.

    FFU with initial high-efficiency two-stage filter screen. Fan from the top of the FFU air intake and after the initial, high-efficiency filter filter after the clean air in the whole air surface at 0.45 m/S + 20% wind speed.

8. What is efficient air supply, integrated air supply? 

Answer: the shell of high-efficiency air supply is made of high-quality cold-rolled steel plate, the surface is sprayed with static electricity, high-efficiency filter with static pressure box, diffuser plate, in the reconstruction and the newly-built one-level clean room, the utility model can be used as a terminal high-efficiency filtering device in a clean shed, etc. , and has the advantages of less investment, simple and convenient construction, etc. 

     Integrated Air Supply filter is a closed structure, low profile, light weight shell, the middle of a high-efficiency filter. It has excellent filtration performance and air duct connected to the filter group, for laminar and non-laminar class of 100,000 to 10 clean rooms. Closed design, to prevent internal voids and side leakage, through the clean room on the air quality requirements. The advantages of its low profile, light weight and disposable design make it suitable for use in hospital operating rooms, laboratories, pharmaceutical industry, microelectronics, film and food processing plants..

9, there is a high-efficiency, no high-efficiency filter baffle current mixing ratio and standard dosage?

 Answer: With or without the current use of the diaphragm sealant is a, B adhesive, and other manufacturers are using polyurethane adhesive. A, B glue mixing ratio of 1:2, its sealing performance is better, but once the ratio is out of balance, it will cause serious consequences, such as: glue, or bubble phenomenon, resulting in filter scrap.

10. What are the standard dimensions and accepted deviations of the diagonal of the primary, intermediate, sub-efficient, and efficient filters? 

Answer: the standard diagonal of the primary, medium and high efficiency filter is the sum of the squares of the two right angles, and then square: find the standard size of the diagonal, that is, the standard diagonal. The permissible deviations for general filters are: for filters larger than 700 mm, the permissible deviations on the diagonal are less than or equal to 4.5 mm and less than or equal to 700 mm, the diagonal tolerance is less than or equal to 2.3 mm.

11. What is resistance, initial resistance, and final resistance?

 A: Resistance: the fiber makes the air flow around, creating a small resistance. The sum of the numerous fiber resistance is the resistance of the filter.

    Initial Resistance: the air resistance of the undusty tested filter when passing through the rated air volume.

    Final resistance: refers to the rated air volume, due to filter dust, and make its initial resistance rise to the specified value, generally 2 times the initial resistance, can also be recommended by manufacturers, units with PA said.

12, atmospheric dust, artificial dust and artificial dust composition ratio? 

Answer: atmospheric dust refers to the suspended particles in outdoor or indoor natural air, while artificial dust mainly consists of road dust, carbon black, and short lint, its constituent ratio is respectively: 72% , 25% , 3% and so on constitutes.

13. What is a subject filter, a terminal filter? 

A: A filter that performs performance tests against a standard is called a test filter.

  A terminal filter is a filter used to capture the artificial dust of a test filter.

14.What is rated air volume? What is dust capacity? 

Answer: the handling air volume per unit time of the filter designed by the manufacturer, expressed in M 3/h, the dust capacity is the product of the total mass of artificial dust and the average weighing efficiency of the filter under test, expressed in units of“G”.

15, the standard folding number of high-efficiency filters with baffles, and the factors affecting and determining its folding number?

 Answer: the standard folding number of high-efficiency filter with baffle is determined by the height of baffle paper and the tightness of baffle paper and filter paper when assembled. For example: wooden frame (610 * 610 * 120) mm filter of the standard folding number is: first remove both sides of the board thickness, then 610-(20 * 2) = 570 mm, its interval number is 57042 = 71.25 fold, the result is about 70 ~ 72 fold.

16.What is the frame and support of the filter? 

Answer: the frame of the filter is refers to: contain filter material, maintain the shape of the filter, bear, when the external force of the object.

What do you mean, “Support”? The part of a filter material that supports or keeps the air passage between the filter materials in a certain shape.

17. What is clean room, cleanliness, and local space purification? 

A: a clean room is a room or area where environmental control is required for dust and microbial contamination.

Local space purification is: only to make the indoor work area specific local space with suspended particles concentration to achieve the required level of air cleanliness.

Cleanliness refers to: the clean environment unit volume of air containing more than or equal to a suspended particles allowed statistics.

18.What are the two test states for filters? Test method for air filter and test method for filter efficiency? 

Answer: the Test status of the filter is: dynamic test and static test.

Filter testing methods are: sodium flame method and oil mist method.

Filter efficiency testing methods are: atmospheric dust test and artificial dust test.

19. What is dust concentration? How to sample in the clean room (area) and how to arrange the sampling points evenly? How to judge the level of clean room (area) ? 

Answer: refers to the unit volume of air containing suspended particles or mass.

When the unit is expressed in grains per liter, it is called a counting concentration; when the unit is expressed in mg/m3, it is called a weighing concentration.

   Sampling in clean rooms shall be evenly distributed on a horizontal plane at a height of 0.8 m above the ground. More than 5 points, can also be in the ground 0.8 m ~ 1.5 m height of the area layering layout. The air supply and pressure difference should be determined while sampling, and the return air outlet should be avoided. The sampling points in the clean room should be arranged evenly to avoid sparsity of sampling points in a local area.

The clean room level is determined on the basis of two conditions:

The average particle concentration at each sampling point must be below or equal to the specified level limit, i.e. AI ≤ level limit.

The upper 95% confidence limit of the mean of the particle concentration at all sampling points must be below or equal to the specified level limit, i.e. UCL ≤ level limit.

20, air filter appearance of the size of the principle of expression and appearance requirements?

 A: air filter shape size of the principle is: air through the direction of the depth, air through the direction of the vertical surface when the correct installation of the vertical length as height, horizontal length as width.

21. How are air filters classified by performance (type, media change) ? 

Answer: according to the type of classification: flat, folding, bag, winding type; according to the replacement of filter material points: can be cleaned, can be cleaned, a one-time use.

22. The principle and basis for the customer to judge whether the air filter (primary, medium and high efficiency filter) is qualified or not? 

A: if a sample is taken and one of the main items or two other items in the test are found to be unqualified, the sample will be considered as unqualified. If a sample is found to be unqualified at the time of sampling, the sample will be taken twice as often, if there is still a non-conforming, the batch of filters for non-conforming products;If more than 3 filters (including 3) have the same defect, the whole batch of products are also substandard.

23, air filter in the label, packaging, transportation process should pay attention to what problems?

 A: label: each filter must be marked in the visible part, if necessary, should also indicate the direction of air flow, indicate at least the product name, filter model specifications, efficiency under rated air flow and initial resistance, manufacturer name and date of manufacture of the product.

Packing: the packing shall ensure the protection of the ex-factory qualified filters from external damage during handling, transportation, handling and storage until installation by the user. The strainer should be placed in a plastic bag and protected at both ends with a hard plate of the same size as the end surface before packaging.

Transportation: in the process of transportation of the filter, according to the packaging signs placed, and take fixed measures, stacking height so as not to crush.

24. Determination of the efficiency of particle-size grouping counting of atmospheric dust? Answer: under the rated air volume, generally uses two dust particle counter simultaneously to measure on the tested filter