Through the actual construction, this paper summarizes the key points of clean air conditioning system construction. First of all, we must pay attention to the selection, purchase and storage of materials. In the production stage of air duct, it is necessary to have clean processing place and clean processing machines and tools, and the processing personnel should have high technical level and good quality. During the installation of air duct, ensure that the construction environment is pollution-free, and the system air duct must be clean and dust-free.
Personnel participating in the installation shall wear dust-free clothes, masks and shoe covers. All instruments and materials used shall be cleaned and checked to be qualified with dust-free paper. The smoke control and exhaust system of the clean room shall not be omitted. The commissioning of the clean system must be planned carefully, organized by relevant personnel and carried out according to relevant specifications.
In recent years, clean air conditioning has been widely used in scientific research, medical treatment, high-tech product production, laboratories, electronic products, precision instruments production. With the continuous expansion of the scope of use of clean air conditioning, the level of cleanliness is also improving. Many clean air conditioners have achieved success through careful design and construction. However, some clean air conditioning systems are degraded to use because they fail to meet the requirements of cleanliness after design and construction, and even scrapped and converted to general air conditioning.
Clean air conditioning system has high technical requirements, high construction quality requirements and large investment. Once it fails, it will cause waste in terms of financial, material and human resources. Therefore, it is necessary to do a good job in clean air conditioning system. Besides perfect design drawings, it also requires high-quality and high-level construction. In this paper, through the construction of clean air conditioning project, some experience will be introduced to you for exchange.
1. The material of air duct is the basic condition to ensure the cleanliness of air conditioner
Material selection. The air duct of clean air conditioning system is generally processed by galvanized steel plate. The galvanized steel plate shall be of high quality, and the standard of galvanized layer shall be more than 314g / m2, and the coating shall be uniform, without peeling and oxidation. Hangers, reinforcement frames, connecting bolts, Huasi, air duct flanges and rivets shall be galvanized. The flange gasket shall be made of flexible, dust-free, soft rubber or latex sponge with certain strength. The external insulation of air duct can be made of flame-retardant PE board with a unit weight of more than 32K, with special adhesive. Fiber products such as glass wool shall not be used.
Material procurement. Material purchasing must select the products of manufacturers with quality assurance from the same kind of products according to the plan. During the physical inspection, the specification and finish of the material shall also be paid attention to, and the flatness, corner squareness and adhesion of the galvanized layer shall also be checked for the plate. In the process of transportation after purchase, the materials shall be well packed, moisture-proof, impact proof and pollution proof.

Storage of materials. Materials for clean air conditioning shall be stored in a special warehouse or in a centralized manner. The storage place shall be clean, free from pollution sources and avoid humidity, especially for the air valve, air outlet, muffler and other parts, which shall be packed and stored tightly. The storage time of clean air-conditioning materials should be shortened, and they should be purchased as needed. The plate used for making the air duct shall be transported to the site as a whole to avoid the pollution caused by the handling of bulk parts.

2. To ensure the cleanliness of the system, make sure that the air duct is manufactured properly.
2.1 preparation before air duct fabrication. The air pipe of the clean system shall be processed and manufactured in a relatively sealed room. The indoor walls should be smooth, dust-free and dust-free. The floor can be paved with thickened plastic floor. The joint of floor and wall should be sealed with tape to avoid dust. Before air duct processing, the room must be clean, dust-free and pollution-free. It can be cleaned repeatedly with a vacuum cleaner after cleaning. The tools used to make the air duct must be cleaned with alcohol or non corrosive detergent before entering the manufacturing room. It is not possible or necessary to enter the production room with production equipment, but it must be kept clean and free of dust. Workers participating in the production should be relatively fixed. When entering the production site, they must wear disposable dust-free hats, gloves, masks, and work clothes should be changed frequently. The materials for production shall be scrubbed with alcohol or non corrosive detergent for two or three times before entering the production site for use.
2.2 key points of air duct manufacturing of clean system. After processing, the semi-finished products shall be scrubbed again before entering the next process, and the air duct shall be combined and shaped immediately after blanking and biting, and shall not be placed for a long time. The flange of air duct shall be processed in such a way that the plane of the flange is flat, the specification is accurate, and the flange is matched with the air duct, so as to ensure the good sealing of the joint when the air duct is combined and connected.
There shall be no transverse joint at the bottom of the air duct, and the longitudinal joint shall be avoided as far as possible. The air duct with large specification shall be made of the whole plate as far as possible, and the stiffeners shall be reduced as far as possible. If the stiffeners must be set, the compression stiffeners and the stiffeners inside the air duct shall not be used. Joint angle or corner undercut shall be used as far as possible for air duct manufacture, and snap type undercut shall not be used for clean air duct above grade 6. If the galvanized layer at the undercut is damaged, the galvanized layer at the rivet hole and flange welding position is damaged, anti-corrosion measures must be taken. The flange crack of air duct joint and the surrounding of rivet hole shall be sealed with silica gel. The air duct flanging must be flat and even. Flanging width, rivet hole and flange screw hole must be carried out in strict accordance with the specification requirements. Flexible short pipe must have smooth inner wall. Generally, artificial leather or plastic can be used. Soft rubber shall be used for air pipe inspection.
3. The handling and installation of clean air duct is the key to ensure cleanliness
3.1 preparation before installation. Before the installation of the clean air conditioning system, the schedule must be made according to the main construction procedures of the clean room. The schedule must be coordinated with other disciplines and implemented in strict accordance with the plan. The installation of clean air conditioning system must be carried out after the completion of painting, sound absorption, elevated floor and other aspects of the construction discipline (including ground, wall and floor). Before installation, the air duct positioning, lifting point installation and other works shall be completed indoors, and the damaged wall surface and floor slab during lifting point installation shall be repainted. (www.iwuchen.com)
3.2 after indoor cleaning, the system air pipe shall be transported in. Attention shall be paid to the protection of the head during the handling of the air duct, and the surface cleaning work shall be carried out before the air duct enters the site.
3.3 workers participating in the installation shall wear dust-free clothes, masks and shoe covers after being blown and drenched. The tools, materials and components used shall be alcohol scrubbed and inspected by dust-free paper. They can enter the construction site only after they meet the requirements.
3.4 the air pipe fittings and components shall be connected by opening the head and connecting at the same time. There shall be no oil stain in the air pipe. The flange gasket shall be made of materials with elastic strength that are not easy to aging, and straight seam splicing is not allowed. The end of the opening shall remain closed after installation.
3.5 the air duct insulation shall be carried out after the system pipeline installation and air leakage test are qualified. After the insulation is completed, the room must be thoroughly cleaned.
4. About the smoke control and exhaust of the clean room.
After the clean room is put into use, it is generally in a positive pressure state, and the clean room is well sealed, with zigzag flow of people and logistics channels. Once a fire is found, it is difficult to evacuate and put out the fire. At the same time, because the heat of the fire source is not easy to emit, the indoor materials and materials are heated quickly, which is easy to ignite and expand the fire disaster area At present, the national code for design of clean workshop (GB50073-2001) has made strict regulations on the evacuation walkway, decoration materials and fire resistance limit of clean room, and has made specific regulations on the fire prevention, explosion-proof measures, fire damper setting, smoke control measures, fire water supply and automatic spray of exhaust system. Therefore, the construction of the smoke control and exhaust system in the clean room must be carried out in accordance with the relevant regulations, especially the pipe layout and embedded parts of smoke control and exhaust must be coordinated with the construction discipline and carried out synchronously to ensure no leakage.
5. Test carefully and orderly to ensure the success of one-time commissioning of clean air conditioning system.
5.1 after the installation of the clean air conditioning system, the air conditioning room and the air conditioning room must be cleaned and cleaned. All irrelevant objects must be removed. The paint on the walls, roofs and floors of the air conditioning room and the room must be checked carefully for damage and completion. The filter system of the equipment must be checked carefully. For the end of the air supply system, the air vent can be directly installed (the system with cleanliness above level 6 can be installed with high efficiency Filter), carefully check the electrical, automatic control system, power supply system, and confirm that all systems are in good condition before commissioning.
5.2 make detailed commissioning plan, arrange personnel to participate in commissioning, and prepare necessary tools, instruments and measuring tools.
5.3 the test run must be conducted under the unified organization and command. During the trial operation, the fresh air filter screen shall be replaced once every 2 hours, and the end with high efficiency filter shall be replaced and cleaned regularly, generally once every 4 hours. The trial operation must be carried out continuously, and the operation conditions can be understood from the automatic control system for various data of each air conditioning room and equipment room, and adjusted through the automatic control system. The test run time of clean air conditioner must conform to the time specified in GB50243-2002.
5.4 after trial operation, the system can be tested for various indicators after reaching stability. The test contents include air volume (wind speed), static pressure difference, air filter leakage, indoor air cleanliness level, indoor floating bacteria and settling bacteria, air temperature and humidity, indoor air flow manifold, indoor noise and other indicators, which can also be carried out according to the design cleanliness level or the level requirements under the agreed acceptance status.
6. Construction example
In recent years, the clean air-conditioning system constructed by the company according to the above methods has been successful, among which the one with higher requirements for cleanliness and the most ideal commissioning effect is an electronic product factory in Wujiang, Suzhou, Jiangsu Province. The project is a Taiwan funded enterprise, with a clean air conditioning area of 6000 square meters, of which 3000 square meters is a computer core shell processing area, with a cleanliness level of 7, a temperature requirement of ± 0.2 ℃, and a humidity requirement of ± 5%. Another 3000 square meters is a computer assembly area, with a cleanliness level of 6, a temperature requirement of ± 0.02 ℃, and a humidity requirement of ± 1 ‰. The air-cooled heat pump central air conditioner is used in the cleanliness level 7 area, with four clean air conditioners (two for standby and two for use).
DDC six pipe fan coil plus fresh air is used for cleanliness level 6 area. The fresh air is fed into the room from the elevated floor. The branch pipes of the fresh air are set in the return air column. Each branch pipe is equipped with an electric control valve for automatic control. After careful construction and strict inspection, the project has been successfully tested once after commissioning. The level 6 clean air conditioning area is close to the level 5 standard, and the level 7 air conditioning area is up to the level 6 standard. The whole testing process is carried out by the testing team of Taiwan Party hired by the owner, and the owner is very satisfied after the completion of the project.
In a word, to ensure the success of clean air conditioning system construction, the following principles should be grasped:
Strictly control the material purchase and the dust-free inspection of the process.
Establish various systems to ensure clean air conditioning construction.
Strengthen the technical and quality education of construction personnel.
Prepare all kinds of tools and instruments.
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).