Views: 0 Author: Site Editor Publish Time: 2021-07-30 Origin: Site
With the continuous development of science and technology, the production and modern scientific experiment activities of modern industrial products are increasingly high, especially microelectronics, biopharmaceuticals, medical institutions, precision manufacturing, food processing, etc. Have high quality, high purity, high reliability indoor environment. Air clean technology has become an indispensable basic conditions for modern industrial production, medical and scientific experimental activities, and is an important means to ensure product quality and environmental safety, which are increasingly widely used in various industries.
CleanroomThere must be a certain air cleanliness level, to control multiple parameters (air cleaning degree, air volume, wind speed, pressure, temperature, humidity, bacterial concentration, etc.). Clean air conditioning system is the main means of implementing clean room control. The clean air conditioning system has the following characteristics compared to the general building air conditioning system:
1) Ensure the temperature and humidity required by the production process;
2) Guaranteed the purification and sterilization of the air;
3) Control the airflow and wind speed in each region;
4) Ensure reasonable airflow flow and pressure distribution between different functions;
5) Can exclude harmful gases to ensure indoor air quality;
Reasonable airflow flow and pressure distribution are critical to clean air conditioning systems. Influence of clean room return air system on air flow tissue:
CleanroomAccording to the air flow tissue, there is a unidirectional stream, non-unidirectional stream, radiosity, mix flow. Multi-unidirectional stream, non-single stream, and mixed stream (partial one-way). One-way stream is used to use \"piston \" extrusion effect, quickly discharge the indoor pollutant, the flow line is parallel, no eddy current, clean degree.
From a general air conditioner, the main factors affecting the room airflow tissue and air conditioning parameters are the arrangement of the air outlet, and the returning stain has little effect on the various conditions of the room. Therefore, when designing clean air conditioning, many designers are also very casual for this concept, and they are very casual, finding the empty wall corners or wall arrangement, completely regardless of the indoor airflow flow to the process of process operation. , Make the clean room lose meaning.
Some designs are located next to the unidirectional streamlined workbench. Indoor contaminated air flows to clean work tables, which seriously affects protected areas; some design returns (row) wind and distance away from production of pollution process equipment (such as crushing Machine, etc.), the contaminated air generated by these process equipment flows to relatively clean areas or even a complete cleaner.
\"Medical Industry Clean Factory Design Specification\" GB50457-2008 clearly stated that the position of returning stretches should be away from clean workbenches; there should be ventilation in the vicinity of easy pollution; there is a local exhaust device or a process equipment that needs to be exhausted. Arranged in the lower wind side of the clean room. Therefore, in the clean room air conditioning design, there must be a building basemap and process arrangement. Design according to process requirements: When equipped with high-efficiency feed, try to cloth.
When arranging the wind, according to the characteristics of the production process, the cleanliness requires high, the returning stretch is arranged away from the clean workbench; the dust is produced or produced, the back (row) is arranged in the equipment, so that To ensure the cleanliness of the clean room, the safe and effective use of clean room process equipment.
Another problem in clean room retraction design is that there is too little in the returning air, and the return air speed is large. Some clean room air conditioning design, a clean area is very large, 4 high-efficiency air outlets, but the back is only one, arranged in a wall. In this way, the full room air flows to one place, and there is inevitably there is a dead angle. The clean air is difficult to reach, so that the area of dust particles increases, affecting cleanliness. The return wind speed is large, and the high temperature can be formed in the vicinity of the returning stretch, so that the dust particles are diffused, and the air quality of clean room is also affected.
Therefore, non-single-way flow room returning stains should be arranged according to the air volume, the wind speed cannot be too large, and it is advisable to not more than 2m / s. The returning air is placed on both sides (or more) walls, in order not to increase the sanitary corner, generally diagonally arranged. When the cleansing chamber width is not more than 3m, it can be arranged in one side.
Any baked space seal to maintainCleanroomThe sterile and cleanliness is nothing, only the pressure in the sterile area is higher than the outside world to prevent the invasion of pollutants. And there is a different pressure control between different levels of clean function in the clean area to ensure that the clean gas flow is oriented, and the airflow can only flow from the clean area to the non-cleaning area, from the high-level clean room to the low level clean room, from the same Clean room cleanliness requires high area flow to a low area, only guarantees that it can maintain clean indoor gradient pressure distribution unchanged in any case, to truly control cleanliness.