The difference between an air shower and a cargo shower in the electronic workshop

Air showers and cargo showers both play a purification role in electronic workshops, but they differ in the following aspects:
I. Purification object
1. Air shower
Mainly used for personnel purification. When staff enter the clean area of ​​the electronic workshop from the non-clean area, they need to pass through the air shower. The air shower sprays clean air from multiple angles to remove dust, fiber, dandruff, and other pollutants on the surface of personnel's clothes, hair, and the surface of the items they carry. For example, when employees enter the high-precision electronic component production workshop from the ordinary corridor of the factory, after purification in the air shower, the possibility of bringing external pollutants into the workshop can be greatly reduced.
2. Cargo shower
Focus on the purification of goods, equipment, and other items. In the electronic workshop, raw materials, parts, production equipment, etc. need to pass through the cargo shower when entering the clean area. It uses a strong clean airflow to blow off dust, debris, and other impurities on the surface of the goods to ensure that the items entering the clean area meet the clean requirements. For example, wafers and packaging materials of electronic chips must be purified in the cargo shower before entering the clean workshop.
2. Structural design and size
1. Air shower room
Generally designed to be suitable for the size and shape of personnel. Its internal space is mainly to accommodate one or several people standing while ensuring that the sprayed clean air can cover all parts of the human body. The height of the air shower room is usually around 2-2.5 meters, and the width and length are determined according to the number of people passing through each time and the actual site conditions. The size of a single air shower room maybe around 1 meter wide and 1.5 meters long.
The internal structure mainly includes fans, high-efficiency filters, air outlets (usually multiple, distributed in different directions, such as the top and both sides), intelligent control systems (used to control the blowing time, two-door interlocking functions, etc.), and lighting systems.
2. Cargo shower room
In order to accommodate goods of different sizes and shapes, the cargo shower room is larger in size and has a more spacious internal space. Its height may be between 2-3 meters, and the width and length are determined according to the maximum size of goods frequently transported in the electronic workshop. Some large cargo shower rooms can be several meters wide and long to accommodate goods such as large electronic equipment cabinets.
The internal structure includes a high-power fan, a high-efficiency filter, a reasonably distributed air outlet (possibly at the top, side, and bottom to ensure all-round purification of the goods), a cargo conveying device (such as rollers, conveyor chains, etc., to facilitate the entry and exit of goods) and a control system.
III. Purification methods and parameters
1. Air shower room
The purification method is achieved by high-speed, multi-angle clean air injection. The airflow rate is generally around 20-30m/s, and the blowing time is usually set to 10-30 seconds, which can effectively remove dust particles on personnel. The clean air blown out of the air shower room is filtered through a high-efficiency filter, and the filtration efficiency for dust particles with a particle size greater than 0.3μm can reach more than 99.9%, ensuring that the air blown to the personnel is highly clean.
2. Cargo shower room
Use strong airflow to blow the cargo in all directions. Due to the different surface areas and complex shapes of the cargo, the airflow in the cargo shower room is relatively large, and the flow rate may be around 15-25m/s. The purification time depends on the size and complexity of the cargo, and may generally be 30-90 seconds. For dust particles on the surface of goods, it is also required that the air after high-efficiency filtration can effectively remove most particles with a particle size greater than 0.3μm, and the filtration efficiency is also around 99.9%.
4. Frequency of use and operation process
1. Air shower room
When the electronic workshop has frequent personnel in and out, the air shower room is used more frequently. For example, in a large electronics factory, each shift of workers needs to use the air shower room when going to and from work and entering and exiting during work and may use it dozens or even hundreds of times a day.
The operation process is generally that after entering the air shower room, the personnel close the outer door and then press the start button. The air shower room starts to blow and purify. After the purification is completed, the inner door is opened to enter the clean room. Some air shower rooms are also equipped with voice prompts, photoelectric sensors, and other functions to facilitate personnel operation.
2. Cargo shower room
The frequency of use depends on the entry and exit of materials and equipment in the electronic workshop. If the workshop is in bulk or the equipment is updated frequently, the frequency of use of the cargo shower room will be relatively high, but usually lower than the frequency of use of the air shower room.
The operation process is to place the goods on the conveyor of the cargo shower room, close the outer door, start the purification process, open the inner door after the purification is completed, and transport the goods into the clean room. During the whole process, it is necessary to ensure that the goods are not damaged during the transportation process and can be fully purified.