This week we mainly tell about how to operate and maintain the clean room.

When changing filters of clean room we also do not know how to operate will be easy and no meet GMP standard,below are the suggestion and introduction.

1. The detection of air volume and wind speed must be carried out first, and the effects of purification air conditioning must be obtained under the designed air volume and wind speed.

2. Before air volume detection, it is necessary to check whether the fan operates normally, whether the components in the system are installed correctly, and whether there are obstacles (such as whether the filter is blocked or blocked). All valves should be fixed in a certain open position, and the size of the measured air outlet and air duct must be measured.

3. For unidirectional flow (laminar flow) clean rooms, the air supply volume is determined by the product of the average wind speed of the room section and the cross-sectional area. The measured section of the vertical unidirectional flow (laminar flow) clean room is taken as the horizontal section 0.8m from the ground; The horizontal one-way flow (laminar flow) clean room takes a vertical section of 0.5m from the air supply surface. The spacing of measuring points on the section shall not be more than 2m, and the number of measuring points shall not be less than 10, which shall be uniformly arranged. Hot bulb anemometer for instrument.

4. For turbulent flow clean rooms, the air supply volume shall be determined by the air outlet method or the air duct method. See Item 6, Item 7 and Item 8 for the methods.

5. For air outlets without filters, the method in Appendix I of the current national standard Code for Construction and Acceptance of Ventilation and Air Conditioning Engineering (GBJ243) can be followed.

6. For the tuyere equipped with filter, the auxiliary air duct can be selected according to the tuyere form, that is, the straight pipe section with the same section as the tuyere and the length equal to 2 times the side length of the tuyere is made of hard plate, which is connected to the outside of the filter tuyere. On the plane of the outlet of the auxiliary air duct, the measuring points shall be uniformly arranged at least 6 points, and the wind speed at each point shall be measured with a hot-ball anemometer. The air volume is determined by multiplying the average wind speed of the tuyere section by the net sectional area of the tuyere.

7. For the tuyere with the same diffuser, the air volume can be checked according to the air volume resistance curve of the diffuser (ex-factory air volume resistance curve or on-site measured air volume resistance curve) and the measured diffuser resistance (the difference between the static pressure inside the orifice and the indoor pressure). Micromanometer and fine pitot tube shall be used for measurement, or thin rubber tube shall be used to replace pitot tube, but the plane of measuring hole shall be parallel to the direction of air flow. In addition, other methods approved by the professional testing department can also be used.

8. When there is a long branch pipe section on the windward side of the tuyere and the hole has been or can be punched, the air volume can be determined by the air duct method. The distance between the section and the local resistance part shall be measured. The former shall not be less than 3 times the pipe diameter or 3 times the length of the large side of the local resistance part, and the latter shall not be less than 5 times the pipe diameter or 5 times the length of the large side of the local resistance part.

9. For rectangular air duct, divide the measuring section into several equal small sections. Each small section should be as close as possible to the square, and the side length should be no more than 200mm. The measuring points should be set at the center of the small section, but the number of measuring points on the whole section should not be less than 3.

For circular air duct, the measuring section and number of measuring points shall be divided according to the equal area ring method.

Make holes on the outer wall of the air duct to insert the hot-bulb anemometer rod or pitot tube. When using the pitot tube, measure the dynamic pressure first, and then determine the air volume according to the following formula

                 

                 

Suzhou Pharma Machinery Co.,Ltd.

2023/02/08

David