Pressure gradient control in bidirectional switching between standby mode and production mode in biopharmaceutical cleanroom

The bidirectional switching between production mode and standby mode in biopharmaceutical clean workshop may lead to drastic fluctuation and reversal of pressure gradient, resulting in pollution risk, which limits the implementation of such switching operation in actual production. Therefore, a data relationship model is proposed between the supply air volume (valve opening) and the return air volume (valve opening) of the cleanroom, and the total air supply volume and the air supply volume of each cleanroom in the clean pharmaceutical plant are adjusted in a synchronized linear step-by-step manner, with a stepwise Bidirectional switching between production and standby modes. Experimental results show that the new mode switching strategy, when the production mode is switched to the standby mode (reducing the air volume), the step size of 20% can better maintain the stability of pressure gradient. When the standby mode is switched to the production mode (increasing the air volume), the step size of 10% can better maintain the stability of pressure gradient. During the whole bidirectional switching process, the pressure variation of each room can be suppressed within the range of 20%. It lays a foundation for the energy saving operation of biopharmaceutical cleanroom during the non-production period.