In industrial grade clean rooms, pharmaceutical factories are often encountered in engineering planning. According to GMP requirements for clean rooms, several important parameters should be taken seriously.

1、 Airflow organization

The airflow organization form of a clean room is a key factor in determining the cleanliness level. The airflow organization form commonly adopted in current planning is determined based on the cleanliness level. For cleanrooms with a capacity of 300000, the top delivery and top return method is often used. For cleanrooms with a capacity of 100000 and 10000, the upper delivery and lower return airflow method is generally used. For higher levels, the horizontal or vertical unidirectional flow method is used.

2、 Ventilation rate

The air exchange rate of a general air conditioning system is only 8-10 times per hour, while in industrial grade clean rooms, the air exchange rate is 12 times for lower levels and several hundred times for higher levels. Obviously, the difference in air exchange rate results in a huge difference in air volume and energy consumption. In the planning, on the basis of precise positioning of cleanliness, it is necessary to ensure that the required air exchange rate is met, otherwise the operation results will be unsatisfactory, the anti-interference ability of the clean room will be poor, and the self-cleaning ability will be correspondingly extended, and a series of problems will not be worth the loss.

3、 Static pressure difference

There are a series of requirements, such as a minimum of 5Pa between cleanrooms and non cleanrooms of different levels, and a minimum of 10Pa between cleanrooms and outdoors. The main method of controlling static pressure difference is to supply a certain amount of positive pressure air volume. The commonly selected positive pressure equipment for planning includes residual pressure valves, differential pressure electric air volume regulators, and air damping layers installed at the return air outlet. In recent years, in planning, it is common to choose a method that does not require positive pressure equipment but instead allows the supply air volume to be greater than the return air volume and exhaust air volume during initial debugging, and correspondingly equipped with an automatic control system to achieve the same effect.

4、 Cleanliness

From this, it can be seen that those with high dust concentration have low cleanliness, while those with low dust concentration have high cleanliness. The air cleanliness level is the central objective for evaluating clean air environments. If the air cleanliness level is not accurately set, it will lead to the phenomenon of large horses pulling small cars, which is neither economical nor energy-saving. The standard of 300000 level originated from a new packaging standard of the Medical Bureau, which is currently not suitable for use in the main product process, but it works well for some auxiliary rooms.

Therefore, the choice of grade directly affects the quality and economic benefits of the product. The dust sources that affect cleanliness mainly come from the dust generated by items during the production process, the movement of operators, and atmospheric dust particles carried by outdoor fresh air. Effective means to control the entry of dust sources into indoor environments include using closed exhaust and dust removal equipment for dust production process equipment, and using coarse, medium, and high-efficiency three-stage filtration for the fresh return air of the air conditioning system and personnel access shower rooms.

5、 Temperature and humidity

Except for special processes, from the perspective of heating, ventilation, and air conditioning, the main focus is on maintaining the comfort of operators, that is, appropriate temperature and humidity. In addition, there are several other goals that should be of concern to us, such as the cross-sectional wind speed of the air duct at the air inlet, noise, and the share of cross-sectional wind speed, noise, illumination, and fresh air volume at the air outlet. These considerations cannot be ignored in planning.

The article originates from Guangdong Purification Engineering: http://www.jmyujie.com/