Negative pressure weighing room is a very common local purification equipment, which has been widely used in pharmaceutical and microbiological research and cleanrooms. The weighing room is mainly used for the proportioning and weighing of drugs, subpackaging of powder and reagents, which can control the overflow and rise of powder and reagents, prevent the inhalation hazards of powder and reagents to human beings, avoid the cross contamination of powder and reagents, and protect the external environment and the safety of indoor personnel.

The selection factors of negative pressure weighing room are as follows:

Sealing and integrity test of high efficiency filter

The negative pressure protection device is usually equipped with DOP detection port, which can be used for filter integrity test.

Laminar wind speed and requirements for centrifugal fans

The wind speed design requirements of the negative pressure protection device are consistent with other Class A laminar flow, that is, 0.45 m/s ± 20%. It is usually designed to be manually or automatically adjustable according to the actual situation (online wind speed monitoring). If online wind speed monitoring is adopted, wind speed sensor shall be equipped. The centrifugal fan can control the wind speed. When the wind speed of the fan fails to meet the requirements, it is sensed by the wind speed sensor and transmitted to the frequency converter, which regulates the motor frequency. When the fan is abnormal, it can be displayed through the filter differential pressure gauge and touch screen.

Monitoring and alarm of primary, intermediate and high efficiency filters and fans

When monitoring and recording the use of primary, intermediate and high efficiency filters and fan operation, 4 differential pressure sensors can be equipped: to control the indoor and outdoor negative pressure, middle and high efficiency resistance, high efficiency resistance of air supply and high efficiency resistance of exhaust. At the same time, its resistance to the equalizing membrane and the primary, intermediate and high efficiency filters shall be displayed on the touch screen. The differential pressure sensor adopts the PLC controller to dynamically control the working state of the weighing room online, which can be stored, printed and displayed. When the differential pressure sensor deviates from the set working state, it can automatically correct, and there is a deviation alarm when correcting.

   

                 

              

Suzhou Pharma Machinery Co.,Ltd.

2022/10/21

Spencer