How to set up the air supply outlet and return outlet in the factory clean room

Many factories require the construction of clean rooms because of the particularity of products, and to ensure the cleanliness of the clean room, it is closely related to the air distribution design. The air distribution design is realized by the reasonable arrangement of air supply outlet, air return outlet and exhaust outlet. If the air supply volume, return air volume and exhaust air volume are calculated correctly, the desired effect can not be achieved if the tuyere layout is not reasonable. How to set up the air supply outlet and return outlet in the clean room of the workshop?

1. For non-unidirectional flow clean rooms with high cleanliness requirements or clean rooms with large aspect ratio, the air supply form with small air volume and more air supply ports should be selected as far as possible; And the return air outlet should also choose the small air volume and the number of return air outlet.

2. For the cleanroom with cleanliness of 1000 class, the form of bilateral lower return air is selected. For clean rooms with cleanliness below class 1000, unilateral lower return air can be used when the width of the clean room is not more than 3m. When greater than 3m, it is advisable to use bilateral lower return air; When the width of the clean room is large, if the bilateral lower return air cannot meet the requirements of the air flow organization, the return air outlet (in the form of return air column) should be added at 1/2 width of the clean room to reduce the eddy current area.

In the specific planning and design of workshop clean room, it should be flexible according to the size of cleanliness, the position of process equipment and other conditions. The general principle of the layout of the return air outlet is: adapt to the air supply outlet, cooperate with the air supply outlet, so that the clean air is fully diffused, fully diluted indoor air flow, and evenly outflow from the room.

3. In addition, the air distribution form of upper and upper return can be used in the clean corridor, dressing room and other non-working surfaces, but the air distribution form of upper and upper return should not be used in the operation room of the clean room. If the conditions allow, in the non-working face is better can also use the upper feeding side of the lower flow organization form, why is this?

Because of the following defects in the air distribution form of the upper return:

At a certain height, there are more large particles of 5um (because of their poor ability to follow the air flow), and the particle concentration of 0.5um is often measured to meet the cleanliness standard, while the particle concentration of 5um is not up to the standard.

If it is a local 100-level clean room, if the upper and upper return scheme is used, the wind speed in the working area is often very small, it is difficult to reach the standard, the self-cleaning time is long, it is easy to cause the short circuit of the air supply, so that part of the clean air and fresh air can not participate in the dilution of the whole room. Thus, the cleanliness and sanitary effect are reduced, and the pollution particles are easy to pollute the operating points they pass through during the rising process.

In general, the clean room layout of air supply and return air outlet, to ensure that each area can have high clean air delivery, return air system can quickly discharge pollutants to the outdoors, purification workshop should be reasonable layout pipeline design direction.