Local one-way flow and air outlet in sterile clean room
Local one-way flow and air outlet in sterile clean room
When the area of u200bu200bthe sterile clean room is relatively large, if the operating point requiring level 5 protection is not large, only a local one-way flow area can be set above the operating point, such as a local level 5 air outlet or a laminar flow hood, and Set up turbulent air outlets in other areas, reaching level 7 or level 8.
When sterile...
Text label: sterile clean room, one-way flow clean room, clean air outlet
Local one-way flow and air outlet in sterile clean room
When the area of u200bu200bthe sterile clean room is relatively large, if the operating point requiring level 5 protection is not large, only a local one-way flow area can be set above the operating point, such as a local level 5 air outlet or a laminar flow hood, and Set up turbulent air outlets in other areas, reaching level 7 or level 8.
When the area of u200bu200bthe sterile clean room is small, is it necessary to set up a turbulent air outlet on the side after setting a local one-way flow above the level 5 operating point? In other words, the local level 5 needs to be set in the background environment of level 7 (or level 8) (that is, the local level 5 under level 7), so the turbulent air outlet must be set around it, right? Woolen cloth?
Local level 5 should be in the background of level 7 (or level 8) in order to reduce the interference of the environment to the level 5 area. The key is how this level 7 (or level 8) background environment was formed? Is it necessary to set up another turbulent air outlet, or can rely on the local level 5 itself.
If the room area is large, and there may be work points other than the 5-level operating point, it may be necessary to set up turbulent air supply outlets in the surrounding area. If the area is not large, and there is no long enclosure under the filter in the core area, it is not necessary to do so (preferably no more than 30cm), because the local level 5 has a contribution to the purification of the environment.
A class 6 sterile clean room with a volume of
2.5m×10m2u003d
25m3
If it is selected according to the data of the national standard (clean pharmaceutical cleanroom design specification), the number of air changes (static) of grade 6 should be ≥50 times, and the safety factor of 1.1 times should be considered, and the air supply volume should be
Qu003d1.1×50×25u003d1375m3/h
2 484mm×484mm×220mm high-efficiency filter air supply ports with corrugated plate should be installed, each with a rated air supply volume of 1000m3/h. According to the filter principle, in order to prolong the service life, the actual air volume of the filter should be selected according to 0.7~0.8 times of its rated air volume. Now the total air volume of the two filters is 1375m3/h, which meets this requirement.
At this time, the area of u200bu200bthe plane part of the air supply port (diffusion plate) will be slightly larger than the section of the filter, about 2×0.3m2u003d0.6m2.
If these two tuyere are arranged together, it can form
1375/(0.6×3600)u003d0.64m/s
The air supply speed.
If you want to reach the local level 5 on the working surface, the wind speed of the one-way flow on the working surface (generally sterile clean room) should not be less than 0.25m/s, and the required air supply speed is
0.25×1.56u003d0.39m/s
It can be seen that the area of u200bu200bthe air outlet can be expanded at this time
0.64/0.39u003d1.64 times
That is, 0.6×1.64u003d0.98m2≈1m2.
At this time, the area of u200bu200bthe centralized air supply port (1m2) is equivalent to 1/10 of the room area (10m2) (referred to as the centralized air supply area ratio). Considering a certain safety factor, 1/8 can be taken. That is to say, for a general sterile clean room, when the area of u200bu200bthe centralized air supply port reaches 1/8 of the room area, the lower part of the centralized air supply port (without enclosure) can reach level 5 (the use area of u200bu200blevel 5 should be slightly smaller than the area of u200bu200bthe air supply port), while the surrounding area can reach level 5. up to level 6.
If this centralized air supply volume of 1375m3/h is used in the surrounding Grade 7 area, since the number of self-purification ventilation for Grade 7 is only half or less than 50 times/h, the applicable area will be more than doubled. In other words, When the centralized air supply area reaches more than 1/20 of the room area, the lower part of the centralized air supply area can reach level 5, and the surrounding area can reach level 7. Also considering the safety factor, this ratio can be taken as 1/16.
Two points should be noted when doing the above calculations:
①The above calculation is carried out under the condition that there is no enclosure in the central part of the 5th grade, and the return air completely passes through the surrounding area, that is, the surrounding area can fully utilize the cleaning effect of the local 5th grade area.
②The local level 5 area should not be too small, such as the size of a filter tuyere, because in the airflow organization, the airflow in the level 5 area will shrink when it reaches the working surface, and it is too small to be applied.
The above-mentioned 5-level local one-way flow is in line with the principle of centrally arranging the air supply outlets. Zhongjing Global Purification can provide consulting, planning, design, construction, installation and transformation and other supporting services for purification projects such as clean rooms and sterile workshops.
When the room is not big, if the general turbulent air outlet is arranged outside the local 5-level centralized air supply outlet, it will have adverse effects:
(1) If the turbulent air supply port is close to the centralized air supply port, it will definitely interfere with the unidirectional airflow under the centralized air supply port.
(2) If the turbulent air outlet is arranged on one side of the centralized air outlet,
On the other side, there is only one-sided return air outlet, which will interfere more with the local level 5 area, especially the downwind side will be more affected.
In an age when CUSTOM SOLUTION SERVICES is increasingly important, the researchers believe manufacturers should pay close attention to their results.
SUZHOU PHARMA MACHINERY CO.,LTD.’s goal is to achieve customer satisfaction through excellence in design, supply chain management, manufacturing and repair solutions.
SUZHOU PHARMA MACHINERY CO.,LTD. expects to reach the desired profits in the first year and does not anticipate serious cash flow problems.
Visit PHARMA MACHINERY for the best in extraction machine CUSTOM SOLUTION SERVICES supplies and get the most cost effective for your CUSTOM SOLUTION SERVICES solution. Design and customization are also welcomed.