Project CategoryMain project classification
Everyone knows that these "big issues" such as factory location, general graphic design, workshop layout, equipment selection, and production and product quality management are all important for manufacturers to ensure that the production environment meets clean standards and prevent pollution and cross-contamination. Measures. However, in the design and implementation of the purification project, there are some details that need to be worked out, otherwise it is likely to be "a thousand miles of dyke, collapsed in the ant's nest". The project built with great financial resources and energy will not be completed due to the failure of a duct. Appropriate or personnel walking does not achieve the desired effect, affecting product quality.
Air-conditioning purification needs to pay attention to energy-saving air-conditioning purification is a large energy consumer, design and construction need to pay attention to energy-saving measures. In the design, the division of the system and area, the calculation of the supply air volume, the determination of the temperature and relative temperature, the determination of the cleanliness level and the number of ventilations, the fresh air ratio, the insulation of the air duct, and the form of the mouthpiece in the production of the air duct on the leakage rate The influence, the influence of the connection angle of the main pipe branch on the airflow resistance, whether the flange connection is leaking, and the choice of equipment such as air conditioning boxes, fans, and chiller units are all related to energy consumption, so these details must be considered.
Air ducts require both economics and efficiency to focus on centralizing or purifying air conditioning systems. The requirements for air ducts are both economical and efficient in supplying air. The former requirements are reflected in low price, convenient construction, running cost, and smooth internal surface and low resistance. The latter means good tightness, no air leakage, no dust generation, no dust accumulation, no pollution, fire resistance, corrosion resistance and humidity resistance. In operation, sometimes the local resistance of the pipe is much higher than the resistance along the air duct, and this situation needs to be improved. Pipe fittings mainly include elbows, reducers, tees and crosses. The center curvature radius of the curved pipe should be greater than the side length of the rectangular duct, and the diameter of the circle should be 1.25 times. For large-section air ducts, a deflector should be added in the duct to reduce the resistance. In actual installation and construction, this is rarely done. For the reducing pipe, the diameter cannot be changed suddenly, and it should be made into a gradually expanding (shrinking) pipe. The expanding angle of each side of the expanding pipe should be greater than 15 °, and the shrinking angle of each side of the reducing pipe should not be greater than 30 °. The tee of the rectangular air pipe must be bent and diverted along the air flow, and the branch pipe should also have a certain radius of curvature. If you want to divert at 90 °, you should add a deflector in the elbow.
Choosing an air-conditioning box based on climatic conditions The choice of air-conditioning box should take into consideration the climate environment in which it is located. For example, in northern areas with low winter temperatures and high air dust content, a fresh air preheating section should be added to a general-purpose air-conditioning unit, and a water spray air treatment method should be used to wash the air and generate heat and temperature. Reach the required temperature and humidity. In the southern regions where the climate is humid and the dust concentration in the air is low, there is no need to preheat the fresh air in winter, and the initial filtration is used for air filtration and temperature and humidity adjustment. Temperature and dehumidification process, and then through intermediate efficiency filtration and terminal high efficiency or sub high efficiency filtration. It is best to use a variable frequency fan for the fan of the air conditioner. This not only saves energy, but also flexibly adjusts the air volume and pressure.
The automatic control device guarantees the full adjustment. At present, some manufacturers use manual methods to adjust the air volume and air pressure. However, because the control valves that control the air volume and air pressure are in the technical compartment, and the ceiling is also a soft steel ceiling with color steel plates, basically They are adjusted during installation and commissioning. Since then, most of them have not been adjusted. In fact, they cannot be adjusted. In order to ensure the normal production and work of the clean plant, a relatively complete set of automatic control devices should be set up to achieve the following functions: clean room air cleanliness, temperature and humidity, pressure difference monitoring, damper adjustment; high-purity gas, pure water and circulating cooling Detection of water temperature, pressure and flow; monitoring of gas purity, pure water quality, etc. The air filter of the purification air-conditioning system increases the resistance with the increase of the operating time. In order to maintain the air volume, the damper in the system needs to be adjusted. When the system is started during system commissioning, in order to start the fan at no load, the air valve at the fan outlet needs to be closed. After the fan is started, it is very difficult to open it because of the pressure on the air valve. After using the variable frequency speed control device of the fan to control the change of the pressure difference between the front and rear of the air filter, the adjustment of the supply air volume will become very easy and the supply air pressure will be stable. These monitoring devices can be designed as a single system measurement, control system, or as a centralized computer control and management system. When the air conditioner system is stopped without wind or over temperature, the electric heater will continue to supply electricity to heat, causing equipment damage or even a fire. To avoid this situation, protection against wind and over temperature power failure should be provided.
Telephones and fire alarm equipment must not be equipped with clean telephones and intercom telephones, which can reduce the number of people walking in clean areas and reduce the amount of dust. It can also promptly communicate with external parties in the event of a fire, and also create conditions for normal working contact. In addition, a fire alarm system should be set up to prevent the fire from being easily detected by the outside and causing major economic losses.
Multi-machine chiller is more flexible. If a large chiller requires a large cooling capacity, it is not suitable to use a single machine, multiple mechanisms should be used, and the motor should use variable frequency speed regulation to reduce starting power. Multiple machines can be used flexibly, so there is no waste of energy in the "big horse-drawn cart".
The air conditioner room should be located on the side of the clean room. The air conditioner room should be on the side of the clean room. This not only saves energy, but also facilitates the layout of the air duct, makes the air flow organization more reasonable, and saves engineering costs.