The clean room pollution is caused by both physical and human factors, hardware and software factors. For example, the fine particles carried in the process of material entering and leaving, the dust carried by the operator in and out of the clean room, the particles released from the clean room wall , the pollution caused by improper operation of personnel, etc. Ensuring clean room air purification effect is the basic guarantee to prevent clean room pollution. The design, installation and operation control of air purification system should meet the requirements of aseptic control. Therefore, the following measures should be taken.
1.Reasonable layout of clean room buildings.
The workshop should be reasonably laid out according to the requirements of air cleanliness grade. For different preparation workshop. Clean room of different clean level should be designed strictly. According to the requirements of air volume, air exchange times, temperature and humidity.
2.Selection of equipment according to cleanliness of workshop.
The areas requiring local high cleanliness purification, local purification equipment such as laminar flow hood should be adopted, and attention should be paid to the organization of air flow to conform to laminar flow pattern. The function section of the air conditioning unit should be complete, the design should be reasonable, and the filters of primary, middle and high efficiency should be selected properly The air cleanliness grade of the weighing room or the material preparation room in the clean room (area) should be in line with the production requirements. There are dust catching measures and measures to prevent cross-contamination.
3.Prevention of cross-contamination.
It should be noted that direct return air discharge of clean air can not replace dust collection facilities. First, dust collection measures should be considered. If cross-contamination can not be avoided, the air purification system does not use return air. Another measure to prevent cross-contamination is to maintain negative pressure with adjacent rooms.
4.Construction of Air Conditioning Purification System in accordance with Construction Procedure.
The construction of air conditioning purification project should follow certain construction procedures, and all specialties should coordinate well. Strict dust and pollution prevention measures should be taken in the process of making ventilation pipes. After installation of air duct system, air tightness test should be carried out. After the air conditioning purification system is installed, the air conditioning equipment shall be tested.The determination of air volume, wind speed, air flow pattern, leak detection, empty, static and dynamic test of clean room, microorganism, noise and illumination should meet the requirements of specifications and design. The air purification system should be cleaned, maintained and maintained in accordance with the method and cycle prescribed in the document. The primary and intermediate filters should be replaced regularly.
5.Regular air testing.
The air in the clean room should be tested regularly according to the requirements of the documents (standard operating procedures). The contents of the test should include not only the detection of sedimentation bacteria (or plankton bacteria) and dust particles, but also the number of air exchange and wind speed.