What is the design redundancy of the compressed air system
In chip manufacturing, the amount of redundancy in the design of compressed air systems needs to be based on fluctuations in gas demand, equipment reliability requirements, process stability requirements three aspects of comprehensive determination, usually used. Combined operation of multiple devices + spare capacity the configuration scheme of the oil-free water lubrication air compressor has become one of the core equipment of redundant design because of its characteristics of oil-free pollution and low maintenance cost. The following is a specific analysis:
core Principles of 1. Redundancy Design
- meets farthest, highest pressure demand: The redundant design needs to be based on the most remote and highest pressure demand gas point in the system to ensure that all areas can get stable gas supply. For example, a lithography machine may require a stable pressure of 0.5-0.7MPa, which should be used as a minimum standard in design and a certain margin should be reserved.
- Coping with gas fluctuation: The gas consumption in the chip manufacturing workshop fluctuates greatly, and the load needs to be balanced by redundant equipment. For example, the use of multiple oil-free water lubrication air compressor combination operation, when a single equipment full load, other equipment can automatically start, to avoid pressure fluctuations affect the process accuracy.
- Ensuring process continuity: Key process links (such as lithography, etching) require extremely high continuity of compressed air, and redundant design is required to ensure stable operation of the system in the event of any single equipment failure. For example, the "N +1" redundant configuration is adopted, that is, N devices meet the normal demand, and 1 spare device is additionally configured.
Application of 2. Oil-free Water Lubrication Air Compressor in Redundancy Design
- oil-free pollution characteristics: Chip manufacturing requires extremely high oil content of compressed air (usually less than 0.01ppm). Oil-free water lubrication air compressor replaces traditional oil lubrication through water lubrication, eliminating oil pollution risk from the source and meeting the requirements of high-end process for gas purity.
- Low maintenance costs: The water lubrication system reduces the use and replacement of lubricating oil, and reduces maintenance frequency and cost. For example, the oil-free water lubrication air compressor only needs to replace the circulating water, water filter and suction filter regularly, and the maintenance period is up to 3000 hours, which is suitable for continuous operation scenarios.
- High efficiency and energy saving: The water lubrication system reduces the friction between the rotors through the water film and improves the compression efficiency. At the same time, with the permanent magnet frequency conversion technology, the speed can be dynamically adjusted according to the gas demand to achieve the balance between energy consumption and pressure. For example, in low-pressure gas supply scenarios (such as 0.15-0.4MPa), its energy efficiency is improved by more than 30% compared with traditional models.
Specific scheme for 3. redundancy design
- equipment selection and combination: According to the maximum air demand and fluctuation, multiple non-oil and water lubrication air compressors are used for combined operation. For example, a chip manufacturing enterprise is equipped with 4 oil-free and water-lubricated air compressors (3 for use and 1 for standby), with a single rated flow rate of 50m & sup3;/min, with a total flow rate of 150m & sup3;/min, which can meet the peak demand and reserve 20% redundancy.
- Pressure regulation and buffering: Pressure regulating valves and gas storage tanks are deployed in layers at the main network, regional distribution system and key equipment inlets to absorb pressure fluctuations through dynamic buffering. For example, the volume of the gas storage tank is determined according to the compressor displacement and gas consumption fluctuation to ensure that the pressure fluctuation range is ≤ ± 0.5%.
- intelligent monitoring and early warning: Deploy online pressure sensors and intelligent control systems to monitor pipe network pressure in real time and automatically adjust equipment operating status. When the pressure is lower than the set threshold, the system automatically starts the standby equipment; when the pressure continues to be abnormal, the alarm is triggered and the emergency filtering program is started.
