Fan Filter Unit Working Method

Detection of indoor airflow pattern

1. Layout of measuring points:

The vertical unidirectional flow (laminar flow) clean room shall have one longitudinal section and one transverse section respectively, and one horizontal plane 0.8m and 1.5m above the ground; The horizontal unidirectional flow (laminar flow) clean room selects one longitudinal section and one horizontal plane of the height of the working area, as well as three cross sections 0.5m away from the supply and return air wall and the center of the room. The spacing of measuring points on all surfaces is 0.2 ~ 1m. One longitudinal section and one transverse section passing through the center of the representative air supply outlet and one horizontal plane of the height of the working area are selected for the turbulent flow clean room. The spacing of measuring points on the section is 0.2m ~ 0.5m, and the spacing of measuring points on the horizontal plane is 0.5 ~ 1m. There shall be measuring points on the center line between two air outlets.

2. Measurement method: observe and record the air flow direction point by point by means of smoke generator or hanging monofilament line, and mark the flow direction on the profile with measuring point arrangement.

Detection of streamline parallelism

1. Observe the air flow direction of the air supply plane with a single wire. Generally, each filter corresponds to an observation point.

2. Use a protractor to measure the angle of the air flow direction deviating from the specified direction, and pay attention to avoiding human interference.

Detection of self purification time

1. This measurement must be carried out when the clean room stops running for a considerable time and the indoor dust concentration is close to the atmospheric dust concentration. If it is required to measure quickly, it can smoke at that time.

2. If the atmospheric dust concentration is taken as the benchmark, the concentration in the clean room shall be measured first, and the machine shall be started up and run immediately. The reading shall be carried out regularly until the concentration reaches the minimum. This period of time is the self purification time. If the manual (such as balan cigarette) is taken as the benchmark, the smoke generator shall be placed at the center of the room 1.8m above the ground, and the smoke shall be stopped for 1 ~ 2min. After 1min, the dust concentration shall be measured at the center of the plane of the working area, and then the machine shall be started up, The method is the same as above.

3. Check attached Fig. 6.3 from the measured original concentration before startup or the pollution concentration (no) 1 min after smoke stop, the concentration (n) when the indoor reaches stability, and the actual ventilation times (n), and obtain the calculated self purification time, which is then compared with the measured self purification time.

                 

                 

Suzhou Pharma Machinery Co.,Ltd.

2022/04/29

David