Clean room/clean room refers to the removal of particulates, harmful air, bacteria and other pollutants in the air within a certain space, and the indoor temperature, cleanliness, indoor pressure, air flow velocity and airflow distribution, noise vibration and Lighting, static control is within a certain range of requirements, and a specially designed room is given. The clean room is characterized by the fact that the external air conditions change, and the interior can maintain the characteristics of cleanliness, temperature, humidity and pressure that were originally set. The main function of the clean room is to control the cleanliness day and temperature and humidity of the atmosphere that the product is in contact with, so that the product can be produced and manufactured in a good environment space. This space is called (clean room/clean room). . The number of air exchanges in different grades of clean room: 100000 grade ≥ 15 times; 10000 grade ≥ 25 times; 1000 ≥ 55 times. Pressure difference: the main workshop is adjacent to the room ≥5Pa
Average wind speed: 10, 100 0.36-0.54 m / s; temperature winter > 16 ° C; summer < 26 ° C; fluctuation ± 2 ° C. The humidity is 45-65%; the humidity of the GMP powder workshop is about 50%; the humidity in the electronic workshop is slightly higher to avoid static electricity.
Noise ≤65dB (A); fresh air replenishment is 10%-30% of total air supply; illumination 300LX
Air flow → initial effect purification → air conditioning → medium efficiency purification → fan air supply → pipeline → high efficiency purification air outlet → blowing into the room → taking away particles such as dust bacteria → returning blinds → initial purification to repeat the above process, you can achieve the purpose of purification.
1. Turbulent Flow
The air enters the clean room from the air conditioner box through the air duct and the air filter (HEPA) in the clean room, and returns to the air from the partition wall panel or the raised floor on both sides of the clean room. The airflow moves in a non-linear motion and is in an irregular turbulent or eddy current state. The turbulent clean room continuously dilutes the indoor air by the supply air flow, and gradually dilutes the polluted air to achieve cleanliness. The number of air determines the level of purification in the definition (the more the number of air changes, the higher the level of purification). This type is suitable for clean room grades of 1,000-100,000.
Advantages: simple structure, system construction cost, and the expansion of the clean room is relatively easy. In some special-purpose places, the dust-free workbench can be used together to improve the clean room level.
Disadvantages: the dust particles caused by turbulent flow are difficult to discharge in the indoor space, easy to pollute
Cheng products. In addition, if the system is stopped and then activated, it will take a long time to reach the cleanliness of the demand.
The laminar air flow moves into a uniform linear shape. The air enters the room from a filter with a coverage of 100%, and is returned by the raised floor or the partition plates on both sides. This type is suitable for the clean room level. For environmental use, the clean room class is generally Class 1~100. Its type can be divided into two types:
(1) Horizontal laminar flow type: The horizontal air is blown out from the filter in one direction, and the return air system of the opposite wall returns to the wind, and the dust is discharged to the outside with the wind direction, and the pollution on the downstream side is generally serious.
Advantages: The structure is simple and can be stabilized in a short time after operation.
(2) Vertical laminar flow: the ceiling of the room is completely covered by the ULPA filter, and the air is blown from top to bottom, which can obtain a higher degree of cleanliness. During the process or the dust generated by the staff can be quickly discharged outside without affecting other work. region.
Advantages: Easy management, stable operation in a short period of time, and difficult to be affected by the operation status or the operator.
Disadvantages: the construction cost is high, the flexible use space is difficult, the ceiling hangers occupy a considerable space, and it is more troublesome to repair and replace the filter.
The composite type combines turbulent flow and laminar flow to provide a partially super clean air.
(1) Clean Tunnel: 100% coverage of the process area or work area with HEPA or ULPA filters to increase the cleanliness level to above 10, saving installation and operation costs.
This type of work needs to isolate the operator's work area from product and machine maintenance to avoid work and quality during machine maintenance. ULSI processes mostly use this type.
The clean tunnel has two other advantages: A. Elastic expansion is easy; B. It can be easily performed in the maintenance area when repairing equipment.
(2) Clean Pipe: Enclose and purify the automatic production line through which the product flow passes, and raise the cleanliness level to above 100. Because the product and the operator and the dusting environment are isolated from each other, a small amount of air can be used to obtain good cleanliness, which can save energy, and no manual automated production line is most suitable for use. It is applicable to the pharmaceutical, food industry and semiconductor industries.
(3) Install a Clean Room: Clean the cleanliness level of the product process area of the clean room with a clean room level of 10,000~100,000 to 10~1000, for production purposes; clean workbench Clean work sheds and clean air cabinets belong to this category.
Clean Workbench: Class Class 1~100.
Clean work shed: a small space for anti-static transparent plastic cloth in the turbulent clean room space, using a separate HEPA or ULPA and air-conditioning blower unit to become a higher-level clean space, the grade is 10~1000 grade, the height is about 2.5 meters, the coverage area is about 10m2 or less, and the four pillars are equipped with movable wheels, which can be used for elasticity.