THE ROLE AND REGULATIONS OF STATIC PRESSURE DIFFERENCE IN CLEAN ROOM

The static pressure difference in clean room is used in many fields, and its role and regulations can be summarized as follows:

1. The role of static pressure difference

(1). Maintaining cleanliness: In the application of clean room, the main role of static pressure difference is to ensure that the cleanliness of the clean room is protected from contamination by adjacent rooms or contamination of adjacent rooms when clean room is working normally or air balance is temporarily disrupted. Specifically, by maintaining positive or negative pressure between clean room and adjacent room, untreated air can be effectively prevented from entering clean room or air leakage in clean room can be prevented.

(2). Judging airflow blockage: In aviation field, static pressure difference can be used to judge the airflow blockage outside the fuselage when the aircraft flies at different altitudes. By comparing the static pressure data collected at different altitudes, the degree and location of airflow blockage can be analyzed.

2. Regulations of static pressure difference

(1).Regulations of static pressure difference in clean room

Under normal circumstances, the static pressure difference in modular operation room, that is, the static pressure difference between clean room and non-clean room, should be greater than or equal to 5Pa.

The static pressure difference between modular operation room and the outdoor environment is generally less than 20Pa, also known as the maximum static pressure difference.

For clean rooms that use toxic and harmful gases, flammable and explosive solvents or have high dust operations, as well as biological clean room that produce allergenic drugs and highly active drugs, it may be necessary to maintain a negative static pressure difference (negative pressure for short).

The setting of the static pressure difference is usually determined according to the product production process requirements.

(2).Measurement regulations

When measuring the static pressure difference, a liquid column micro pressure gauge is generally used for measurement.

Before testing, all doors in modular operation room should be closed and guarded by a dedicated person.

When measuring, it is generally started from the room with higher cleanliness than the inside of the operation room until the room connected to outside world is measured. During the process, the airflow direction and eddy current area should be avoided.

If the static pressure difference in modular operation room is too small and it is impossible to judge whether it is positive or negative, the threaded end of the liquid column micro pressure gauge can be placed outside the door crack and observed for a while.

If the static pressure difference does not meet the requirements, the indoor air outlet direction should be adjusted in time, and then retested.

In summary, static pressure difference plays an important role in maintaining cleanliness and judging airflow blockage, and its regulations cover specific application scenarios and measurement requirements in different fields.