HEPA is an industrial consumable. HEPA installation methods and specifications in order to ensure the clean effect, generally every other period of time must be replaced. At present, most of the purification areas install HEPA at the ceiling air supply outlet. The installation method and the confirmation before installation completely determine whether there is any leakage point in the HEPA. The confirmation before installation provides more effective objective conditions for HEPA installation. So the following problems must be paid attention to during installation. Note: HEPA can only be replaced after air supply of air conditioning system is stopped. The gasket between filter and connecting frame must be tight and leak free to ensure filtering effect.
HEPA installation methods and specification
1. During transportation and storage of HEPA, it shall be placed in the direction marked by the manufacturer. During transportation, handle with care to prevent violent vibration and collision, so as to avoid damage caused by man.
2. Before the installation of HEPA, clean and wipe the clean room. If there is dust in the air conditioning system, clean and wipe it again to meet the cleaning requirements. If HEPA is installed in the technical mezzanine or ceiling, the technical mezzanine or ceiling shall also be fully cleaned and wiped.
3. After the clean room and purification air conditioning system meet the cleaning requirements, the purification air conditioning system must be put into trial operation. After continuous operation for more than 12h, clean and wipe the clean room again and install the HEPA immediately.
4. Before HEPA installation, the package must be unpacked at the installation site for visual inspection, including whether the filter paper, sealant and frame have burr and rust (metal frame), whether there is product certificate and whether the technical performance meets the design requirements. Then carry out leak detection. Those qualified after inspection and leakage detection shall be installed immediately. During installation, the resistance of each filter shall be adjusted reasonably. For unidirectional flow, the difference between the rated resistance and the average resistance of each filter on the same air inlet or air supply surface shall be less than 5%.
5. The frame of HEPA shall be flat. The allowable flatness deviation of each HEPA installation frame shall not be greater than 1mm. And keep the arrow on the outer frame of the filter consistent with the air flow direction. When it is installed vertically, the fold of filter paper shall be perpendicular to the ground.
6. When the seal between the HEPA and the frame generally adopts the methods of gasket, self-adhesive, negative pressure seal, liquid tank seal and double ring seal, the packing surface, filter frame surface, frame surface and liquid tank must be wiped clean. The thickness of the gasket shall not exceed 8mm, and the compression ratio shall be 25% ~ 30%. The joint form and material shall meet the design requirements, and there shall be no leakage at each joint of the frame. When using double ring sealing strip, do not block the hole on the ring cavity when pasting the seal. Double ring seal and negative pressure seal must keep the negative pressure pipeline unblocked.
7. At present, most filters in China are installed by gasket method. It is generally used as sealing material because sponge rubber plate is closed cell type with good air tightness. If necessary, it is better to apply a little glass glue evenly on the sealing strip. When connecting the filter and the static pressure box, the stress around should be even. After 24 hours, the glass glue is dry before running the purification system.