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How is the differential pressure controlled in the clean room

Industrial modular Clean Room time:2021/06/17 15:08:15 click:595

According to the process requirements to maintain a certain small differential pressure between the clean room and the surrounding space, can be positive pressure or negative pressure. The differential pressure can be controlled by the air supply outlet, return air outlet or residual pressure valve.

How is the differential pressure controlled in the clean room

Pressure difference control is a very important link in the purification air conditioning system. Only by controlling the pressure difference in the purification area and ensuring reasonable air distribution can the requirements of purification and process be achieved.

For example, clean plants must maintain a certain positive pressure so that the outside air without purification will not enter the purification area, to ensure the clean level; And through the different pressure difference control of each purification area, to achieve the role of purification partition, in GMP requires that the pressure difference of different purification level area should be controlled not less than +5Pa. In the biosafety clean room, the pressure difference control is the key means to ensure the safety protection barrier. "Technical Code for the Building of Biosafety Laboratory" requires that the negative pressure gradient of the laboratory must be controlled stably and reliably. Therefore, differential pressure control is very important for the purification air conditioning system.

According to the Clean Room Design Code (hereinafter referred to as the Code), if the indoor pressure of the clean room is higher than the external pressure, it is a positive pressure clean room; otherwise, it is called a negative pressure clean room. Positive pressure and negative pressure are relative. A clean room is a positive pressure clean room for the atmosphere, but it may be a negative pressure clean room for another room. The specification stipulates that the pressure difference between different grades of clean room and clean area and non-clean area is not less than 5Pa, and the pressure difference between clean area and outdoor is not less than 10Pa. The positive pressure difference between the clean room corridor and the unclean area should be maintained at least 30Pa. The basic principle of the differential pressure is that the air supply volume is greater than the air return volume, the air exhaust volume and the air leakage volume.