Cleanliness Requirements for Class 100 Clean Room
The requirement of cleanliness of Class 100 clean room is that the dust and bacterial contaminants emitted from pollution sources are diffused in the room as the premise, and the contaminants are diluted by the clean air treated by high efficiency filters, so as to maintain the required cleanliness level of indoor air.
The cleanliness requirement of Class 100 clean room refers to the amount of dust in air environment. Generally speaking, the requirement of cleanliness in class 100 clean rooms is that the amount of particles in the air per unit volume is greater than or equal to a certain particle size. The cleanliness of Class 100 clean room is low when the dust content is high, and that of Class 100 clean room is high when the dust content is low.
The cleanliness grade of class 100 clean room is named after the concentration of particles (> 0.5 um). For example, in a clean room with a permissible concentration of 100 pc/ft3 (about 3520 pc/m3) for particles greater than 0.5 um, the clean concentration is called class 100. Our country's 1984 Code for the Design of Clean Workshops also uses the English grade names - 100, 1000, 10,000 and 100,000, which are still used in engineering. The four grades mentioned above are similar to those in GB50072-2001. The smaller the cleanliness level of the clean room, the higher the level. In a clean room of the same grade, according to the technological requirements, the concentration of particles with 1 to 2 sizes can be controlled. For example, the particle concentration (> 0.5 um) in Grade 6 clean room should be no more than 35200 pc/m3 and no more than 293 pc/m3 in Grade 6 clean room.
Cleanliness monitoring and management system for class 100 clean rooms:
Use of clean areas:
(1) Personnel entering the clean area shall regularly conduct training on basic microbiological knowledge, hygiene knowledge and clean operation;
(2) Personnel entering and leaving the clean area must enter the clean area according to the corresponding level of standard operating procedures for entering and leaving the clean area;
(3) Standard operating procedures for the entry and exit of workers in each workshop should specify the number limit of people entering the clean area and strictly implement it.
(4) All materials and appliances used in clean areas must be cleaned in accordance with the prescribed procedures. Goods entering the clean area should be cleaned out of the area and entered through the transfer window.
(5) The air conditioning in the clean area should be carried out continuously. After the end of production, the air conditioning system should continue to operate for 4 hours before stopping. The system must be disinfected before it can be re-run.
(6) Waste should be stored in special containers, cleaned up in time every day, and sent out of the window by the transfer window.
Monitoring of Class 100 Clean Room Clean Zone:
(1) In order to ensure the clean environment and cleanliness of the clean area, regular monitoring of the clean area is needed.
(2) High-efficiency air filters should be replaced if the following conditions are found;
A. When the air velocity is less than 0.25m/s, the air velocity can not be increased even after the initial and intermediate air filters are replaced.
B. The leakage of high efficiency air filter can not be repaired.
Maintenance requirements for clean areas of Class 100 clean rooms:
(1) Safety doors, emergency lights and special alcoholic cabinets should be set up in clean areas.
(2) Records should be kept in the management of clean areas;

(3) In addition to the daily management of the users, the air conditioning system and the air purification equipment in the clean area are overhauled once a year. If abnormal conditions occur during production, they should be overhauled in time and verified after overhaul.

Test and Method of Cleanliness of Class 100 Clean Room
test
The air cleanliness of the clean room shall be tested as follows:
Vacuum test: The clean room has been completed, the purified air conditioning system is in normal operation, and the test is carried out in the absence of process equipment and production personnel.
Static test: Clean room air conditioning system has been in normal operation, process equipment has been installed, indoor test without production personnel.
Dynamic testing: The clean room has been tested under normal production conditions. The detection of air volume, wind speed, positive pressure, temperature, humidity and noise in a clean room may be carried out in accordance with the relevant provisions of general use and air conditioning.
The method of measuring air cleanliness in the working area of class 100 clean room is suitable for counting dust particles whose particle size is greater than or equal to 0.5 micron by light scattering particle counting. For dust particles with particle size greater than or equal to 5 microns, the filter-film microscopy counting method can also be used.
Clean room non-unidirectional flow pattern was once called Turbulence Airflow. Non-unidirectional flow is a kind of non-uniform airflow distribution. Its velocity and direction are different in different places of clean room. This is a common airflow organization form used in clean room. The following figure shows the general distribution of non-unidirectional flow.
Therefore, the number of ventilations required for non-unidirectional flow clean rooms will vary greatly with the required cleanliness and indoor pollutant diffusion.
The air distribution of non-unidirectional flow clean room can be divided into the following categories according to the installation methods of high efficiency filters and return air outlets: top feeding, side feeding, side feeding, top feeding and top feeding.
Among them, the top-feeding and side-down air flow are the most commonly used forms. 5-25 shows several common non-unidirectional flow patterns.
The non-unidirectional flow clean room with diffuse orifice plate tuyere top feeding and side-down return is delivered by diffuser plate through high efficiency filter. The air distribution in the working area is more uniform, and its air cleanliness is obviously better than the surrounding area. Because the surrounding area is continuously involved in indoor polluted air after the air supply enters the room, the cleanliness is poor in the adjacent delivery area. The cleanliness will be worse in areas where air supply cannot be covered between tuyeres or around the corner or edge of the clean room.
Therefore, in order to make the cleanliness of all parts of the clean room as uniform as possible when arranging the top air supply outlet, under certain conditions of the total air supply volume, more air supply outlets or uniformly arrange air supply outlets should be set up appropriately, so as to make the air flow of adjacent air supply outlets converge on the height of the working area as far as possible, so as to ensure the cleanliness required by the working area.
Sometimes in order to satisfy the air cleanliness grade of the key parts of the production process, the position of the air supply outlet can be adjusted according to the layout of the process equipment without affecting the roof of the clean room, the arrangement of lamps and lanterns or not damaging the overall beauty, and the non-uniform layout can be adopted.