Clean Room (Clean Room), also known as clean room or clean room. It is the basis of pollution control. Without a clean room, it is impossible to mass-produce pollution-sensitive parts. This article only briefly discusses the four necessary conditions for achieving cleanliness requirements in clean room purification measures. 

1. Air supply cleanliness To ensure that the cleanliness of the supply air meets the requirements, the key is the performance and installation of the final filter of the purification system. Considering cleanliness requirements, the principle is to use low-performance filters for low-level clean rooms and high-performance filters for high-level clean rooms. Generally speaking: 

1 million grades can choose high and medium efficiency filters; less than 10,000 grades can choose sub-high efficiency or A type high efficiency filters; 10,000 to 100 grades use B type filters; 100 to 1 grades use C type filters . There seem to be two types of filters for each cleanliness level to choose from. The choice of high-performance or low-performance depends on the specific situation: when the environmental pollution is serious, or the proportion of indoor exhaust air is large, or the clean room Particularly important, a larger safety factor is required. In these or one of the cases, a higher type of filter should be selected; otherwise, a lower performance filter should be selected. 

2. Airflow organization The airflow organization of a clean room is different from that of a general air-conditioned room. It requires the cleanest air to be sent to the operating part first. Its function is to limit and reduce the pollution of processed products. For this reason, these principles should be considered when designing the airflow organization: minimize turbulence and avoid bringing pollution outside the work area into the work area; try to prevent the secondary dust from flying to reduce the chance of dust contaminating the workpiece; the airflow in the work area should be Try to be uniform as much as possible, and the wind speed should meet the requirements of craftsmanship and hygiene. When the airflow flows to the return air outlet, the dust in the air should be effectively taken away. According to different cleanliness requirements, choose different air delivery and return methods.

 3. Air supply or wind speed Sufficient ventilation is to dilute and eliminate indoor polluted air. According to different cleanliness requirements, when the clean room has a higher net height, the number of air changes should be appropriately increased. Among them, the ventilation of the 1 million class clean room is considered according to the high and medium efficiency purification system [7], and the rest are considered according to the high efficiency purification system; when the 100,000 class clean room high efficiency filter is centrally arranged in the computer room or the system end adopts the sub-high efficiency filter At this time, the ventilation frequency can be appropriately increased by 10-20%. Four, static pressure difference Maintaining a certain positive pressure in the clean room is one of the indispensable conditions to ensure that the clean room is not or less contaminated to maintain the design cleanliness level. Even if it is a negative pressure clean room, it must have adjacent rooms or suites that are not lower than its cleanliness level to maintain a certain positive pressure, so that the cleanliness of the negative pressure clean room can be maintained.

 The positive pressure value of the clean room refers to the value where the indoor static pressure is greater than the outdoor static pressure when the doors and windows are all closed. It is achieved by the method that the air supply volume of the purification system is greater than the return air volume and the exhaust air volume. In order to ensure the positive pressure value of the clean room, the air supply, return air and exhaust fans are best to be interlocked. When the system is turned on, the air supply fan should be started first, and then the return fan and exhaust fan should be started; when the system is closed, the exhaust fan should be turned off first, and then the fan and air supply fan should be turned off. , In order to prevent the clean room from being polluted when the system is turned on and off. The air volume required to maintain the positive pressure in the clean room is mainly determined according to the tightness of the maintenance structure. In the early stage of clean room construction in my country, due to the poor airtightness of the enclosure structure, it is necessary to maintain a positive pressure of ≥5Pa, which requires 2-6 times/h of air supply; the airtightness of the maintenance structure has been greatly improved, and the same positive pressure is only 1 ~2 times/h air supply; maintaining ≥1OPa also only needs 2~3 times/h air supply.

Committed to Production and R&D aluminium room door、clean room ceiling systems and clean room window