Ventilation to achieve cleanliness in clean Spaces

In order to achieve a clean environment, integrated measures must be provided, including process design, building level, building design, building finish, cleaning of personnel and materials, air cleaning measures, maintenance management, etc. With regard to air purification, the following specific measures are mainly applied [1]:
(1) the air supplied to the clean room shall be air of high purity. Therefore, a high-efficiency or subhigh-efficiency filter (at a low purity level) must be selected as the final cleaning filter to perform the final stage of filtration of air entering the clean room. To protect the terminal filter and extend its service life, the air must first be profiled through a medium efficiency filter.
(2) depending on the clean room class, it is reasonable to choose the scheme of air flow distribution in the clean room. In the working area, avoid the swirl zone, try to ensure that the high purity air sent to the room directly reaches the room. Working area; The flow of air contributes to the cleanliness of the room. Particles are released from the return air outlet.
(3) the amount of air is sufficient not only to reduce dust concentration in the air, but also to ensure a stable air flow structure.
(4) some positive pressure shall be maintained between clean Spaces of different levels, clean and unclean Spaces or between clean Spaces and the outside.