Plant purification engineering solutions
With the rapid development of China's economy, the technology of electronic information industry has reached the world level. With the improvement of the performance and quality of many electronic and micro electronic products and the miniaturization of the production process, the production environment pollution is increasingly required to have a certain degree of air cleanliness and environmental control. According to the analysis of the design scheme of the purification engineering in the electronic industry, there is no unified regulation on the air cleanliness level or the production environment control requirements of the electronic products in China at present, so it is generally based on the code for the design of clean workshop (GB50073-2001) and the practical experience of the electronic product manufacturers to determine the requirements of the cleanliness level and temperature and humidity of the electronic workshop.
In the design process of purification engineering, it is necessary to strengthen the analysis and understanding of the design scheme of purification engineering in the optoelectronic industry, and determine the required cleanliness, temperature and humidity according to the requirements of its specific production process and production process. Then, according to the specific situation of the project, considering the economic bearing capacity of the manufacturer, and combining various factors to determine which purification scheme to adopt, so as to design a scheme that can meet the production and use requirements of Party A, with reasonable project cost, economic and energy saving.
The common ways of clean workshop are as follows:
I. high efficiency air supply outlet of combined air treatment unit water chiller
This is the most traditional design of purification air conditioning system. The combined air treatment unit contains various functional sections, such as mixing section, South primary effect filter section of CSCEC, surface cooling section, secondary return air section (or middle section), heating section, humidification section, medium effect filter section, fan section, etc. The cold source is provided by the water chiller.
Advantages: 1) the air treatment effect is good, because the air is subject to centralized treatment, and the pollution degree is relatively low in the air supply process. The control of temperature and humidity of air supply is more accurate; B. It is more suitable for the workshop with centralized cooling source or larger; C. the air conditioning cold and heat sources can be shared or independent with the general air conditioning system of the workshop; D. the maintenance frequency is low; e. the noise of the workshop is low.
Disadvantages: A. It is necessary to have a matching refrigeration room or an outdoor space for the heat pump unit. In addition, the air conditioning room where the combined air treatment unit is placed, such as the 25000m3 / h combined air treatment unit, is usually about 6450 × 1850 × 2250mm in overall dimension. For the old plant reconstruction project, it is difficult to empty a 20-30 ㎡ machine room; B. the cost is high. Features: A. It is recommended to mix fresh air with return air after centralized treatment, so as to reduce the cold treatment burden of surface cooling section; C. This kind of scheme can generally be applied to low clean and dust-free plants with high cleanliness, such as class 100, class 1000 or class 10000, class 100000, etc.
II. High efficiency air supply outlet of booster fan cabinet of water-cooled cabinet
Compared with the former scheme, this is a relatively simple air conditioning scheme. It can greatly reduce the area of the machine room. The water-cooled cabinet can be arranged in the smaller machine room or the purification workshop according to the specific situation. The booster fan cabinet can also be arranged in the machine room or hung in the machine room or in the mezzanine.
Advantages: a. the effect of air treatment is better, and the air after treatment is less polluted in the process of air supply. The temperature and humidity control effect of air supply can achieve better control. It is mainly controlled in the air handling unit (booster fan cabinet); B. flexible layout. Equipped with cooling source; C. suitable for large and small plants, new and old plants; D. low maintenance frequency; e. low workshop noise.

Disadvantages: A. small area of machine room is required. The cooling tower and cooling water pump shall be arranged; B. the air conditioning unit and air conditioning treatment unit shall be arranged centrally; C. the cost is low. Features: this kind of scheme can be primary return air or secondary return air, depending on the size of the workshop; this kind of scheme can generally be applied to clean and dust-free workshops with cleanliness of class 1000, class 10000, class 100000, etc.

III. FFU air supply outlet of split air conditioner
This is the simplest air conditioning scheme. It is to directly arrange the split air-conditioning cabinet in the workshop and enclose it with color steel, and then open the air return on the color steel plate at the air return of the cabinet (with primary effect filter screen); FFU of KLC fan filter unit is evenly arranged on the ceiling. This scheme is suitable for the dust-free workshop with low indoor temperature and humidity accuracy requirements.
Advantages: A. It does not need to occupy the area of the machine room, and the layout is very flexible; B. It can meet the air cleanliness; C. It has the lowest cost. For example, the initial investment of 300 ㎡ dust-free workshop is about 400000; D. the uniformity of air supply is good.
Disadvantages: A. poor temperature and humidity control; B. air cleanliness; C. high frequency of FFU maintenance.
IV. characteristics of dust-free workshop in the analysis of purification engineering design scheme of electronic industry
A. cleanliness of the dust-free workshop: the brief process of LCD screen making is: cleaning → printing orientation film → friction → sealing the printing layer to distribute the spacer → combination → marking and cutting → LC injection → sticking polarizer → final screen making inspection. In this design, it refers to some dust-free workshops of the end process, and its purification cleanliness is generally class 1000 or class 10000 or class 100000. The dust-free workshop of backlight screen is mainly the stamping workshop, assembly workshop and other dust-free workshops of this kind of products, and its cleanliness is generally class 10000 or class 100000.
B. indoor air parameter requirements: (1) temperature and humidity requirements: the temperature is generally 24.2 ℃, and the relative humidity is 55.5%. (2) large amount of fresh air. Because there are many people in this kind of workshop, the following maximum values can be taken according to the following values: 10-30% of the total air supply volume of the non unidirectional flow clean room; the fresh air volume required to compensate the indoor exhaust air and maintain the indoor positive pressure value; and the fresh air volume per hour for each person in the room
Air volume ≥ 40m3 / h. (3) large air supply volume. In order to meet the cleanliness and heat and humidity balance of the clean room, a large amount of air supply is required. For a workshop of 300 square meters with a ceiling height of 2 and 5 meters, if it is level 10000, the air supply needs to be 300 × 2, 5 × 30 = 22500m3 / H (air change times, is ≥ 25 times / h); if it is level 100000, the air supply needs to be 300 × 2, 5 × 20 = 150000m3 / h (air change times, is ≥ 15 times / h).
Five. Conclusion
Design scheme analysis of purification engineering in electronic industry for the design of air conditioning in clean room of conventional workshop, which air conditioning design scheme should be selected according to the production process requirements of electronic workshop and the economic conditions of Party A, in order to meet the requirements of production process as the premise. According to the past experience, the air conditioning scheme of combined air handling unit can be selected for high requirements; for low requirements and low initial investment, the cabinet FFU can be selected. In a word, the choice of specific scheme depends on the specific situation.
Ed purification is a purification engineering company specializing in the design, construction, commissioning and installation of food aseptic workshop, GMP clean workshop, electronic dust-free workshop, food and pharmaceutical packaging workshop, medical equipment workshop, laboratory purification and other projects. For more knowledge of medical purification industry, please pay attention to WeChat public address: Aide-188 (Ed purify oxygen supply).