What are the high efficiency filter maintenance and high efficiency air filter installation and replacement standards?
In the daily maintenance of clean rooms and various clean workshops, the maintenance of air filters is a big expense, but the maintenance of air cleanliness is necessary for the production of environmental pollution requirements, what is the standard ofhigh efficiency filtermaintenance and high efficiency air filter installation and replacement? In peacetime air filter, especially high efficiency air filter packaging, transportation, installation and use process, should be in accordance with thehigh efficiency air filter manufacturer’sstandard requirements, to ensure the use of high efficiency air filter effect. Each type of air filter in use for a period of time, because the filter material surface collected a variety of dust, so that the air filter efficiency and air filter resistance decline, affecting the central air conditioning unit or clean engineering supporting high efficiency air supply outlet air supply volume, cleanliness and efficiency, at this time need to be replaced in time to ensure the air cleanliness requirements.
High efficiency filter maintenance and high efficiency air filter installation and replacement standards
1. All kinds of air filter, high efficiency air filter before installation, is not allowed to tear or open the packaging bag or packaging film by hand; The air filter should be stored in strict accordance with the direction standard marked on the packing box of the hePA filter. In the handling process of high efficiency air filter, should be handled lightly, to avoid violent vibration and collision.
2. For HEPA filters, the installation direction must be correct: when the filter is installed vertically with corrugated plate combination, the corrugated plate must be perpendicular to the ground; The connection between the vertical filter and the frame is strictly prohibited from leakage, deformation, damage and leakage, etc., after installation, the inner wall must be clean, no dust, oil, rust and debris, etc.
3. Inspection method: observation or white silk cloth wipe inspection.
4. Before the installation of high efficiency filter, the clean room must be comprehensively cleaned and wiped. If there is dust accumulation inside the air conditioning system, it should be cleaned and wiped again to meet the cleaning requirements. If the high efficiency filter is installed in the technical sandwich or the ceiling, the technical layer or the ceiling should also be comprehensively cleaned and wiped.
5. The transportation and storage ofHEPA filtersshould be shelved in accordance with the direction of the manufacturer’s signs. In the process of transportation, should be handled lightly, to prevent violent vibration and collision, can not be forced to load and unload.
6. Before the installation of HEPA filter, the package must be unpacked at the installation site for appearance inspection, including: filter paper, sealant and frame damage; Whether the side length, diagonal and thickness dimensions meet the requirements; The frame has burrs and rust spots (metal frame); Whether the product certificate, technical performance is in line with the design requirements. Then the inspection shall be carried out in accordance with the method specified in the national standard “Code for Construction and Acceptance of Clean Rooms” [JGJ71-90], and the qualified ones shall be installed immediately.
7. High efficiency filters with cleanliness level equal to or higher than 100 for clean rooms shall be leak-detected according to the method specified in the “Code for Construction and Acceptance of Clean Rooms” [JGJ71-90] before installation, and shall meet the specified requirements.
8. When installing high efficiency filter, the arrow on the outer frame should be consistent with the air flow direction; When it is installed vertically, the filter paper crease direction should be perpendicular to the ground.
9. Install coarse effect plate type or folding filter, should make the galvanized net surface in the direction of the back of the air outlet. When installing bag filter, the length direction of the filter bag should be perpendicular to the ground, and the direction of the filter bag should not be parallel to the ground.
10. Under normal use conditions, flat plate, folding coarse or medium effect filter, generally 1-3 months to replace once, the requirement is not strict area, can be replaced with filter material can be soaked with clean water containing detergent, rinse, and then cool dry again; Generally, after washing 1-2 times, a new filter must be replaced to ensure filtration efficiency.
11. For bag type coarse effect or medium effect filter, under normal use conditions (average 8 hours a day, continuous operation), generally use 7-9 weeks should be replaced.
12. For subhePA filters, under normal use conditions (average 8 hours a day, continuous operation), generally used for 5- 6 months, should also be replaced.
13. For the above filter, if there is a differential pressure gauge or differential pressure sensor before and after the filter, the coarse filter, when the differential pressure value is greater than 250Pa, must be replaced; For medium effect filter, when the pressure difference is greater than 330Pa, it must be replaced; For the subhePA filter, when the pressure difference is greater than 400Pa, it must be replaced, and the original filter can not be reused;
14. For high efficiency filter, when the filter resistance value is greater than 450Pa; Or when the airflow velocity on the outlet surface is reduced to the minimum, the airflow velocity can not be increased even after the replacement of the coarse effect and medium effect filter; Or when the surface of the high efficiency filter can not be repaired leakage situation, must be replaced with a new high efficiency filter; If there is no such condition, it can be replaced once every 1-2 years according to the environmental conditions.
15. In order to give full play to the role of the filter, in the selection and use process, the headwind speed of the filter, coarse effect, medium effect filter should not be greater than 2.5m/s, subhigh efficiency filter and high efficiency filter should not be greater than 1.5m/s, which is not only conducive to ensure the efficiency of the filter, but also can prolong the service life of the filter, save costs.
16. Generally do not replace the filter when the equipment is running; If the filter has reached the replacement period and can not be stopped for replacement, only the coarse and medium-effect filter is allowed to be replaced without stopping the fan; Subhepa filter and HEPA filter must stop air supply before replacement.
17. The gasket between the filter and the connecting frame must be tight and leak-free to ensure the filtering effect.
18. For high efficiency filters used in environments with high humidity and temperature, filter paper, separator, and frame materials that are resistant to high temperature and humidity must be selected to meet production requirements.
19. Biological clean room and medical clean room, must choose the filter of metal frame body, and its surface should not be easy to rust, do not allow the use of wood frame plate filter, in order to prevent bacteria, affect the qualified products