The role of compressed air for breathing in a clean room

Technical description of the role of breathing compressed air in clean rooms

In high-end industries such as precision manufacturing, biomedicine, and electronics and semiconductors, clean rooms are the core production environment, and their air cleanliness is directly related to product quality and process stability. As a key infrastructure for a clean room, compressed air for breathing plays an irreplaceable role in ensuring personnel safety, maintaining environmental cleanliness, and driving precision equipment by providing clean power sources and process media. The following explanation is given on its technical value and system specifications:

1. Core support for environmental maintenance

1. Construction of positive pressure environment：
   • By continuously supplying clean compressed air, the positive pressure difference (usually 5-15Pa) between the clean room and the external environment is maintained, effectively blocking the intrusion of external pollutants.
   • In a clean room with a cleanliness level requiring ISO 5 (Class 100), 15-20 complete air replacements are required per hour, and compressed air for breathing needs to account for 30%-40% of the air supply.
2. Air flow organization optimization：
   • When a laminar air supply system is used, the FFU (fan filter unit) driven by breathing compressed air can achieve a vertical one-way air flow of 0.3- 0.5 m/s, ensuring that particles are discharged out of the clean area in the shortest path.
   • In local level 100 working areas, a clean barrier with a width of 0.5-1.0 meters can be formed through an air curtain device driven by compressed air to block the diffusion of particles generated by personnel operations.

2. Personnel safety and security system

1. Respiratory protection supply：
   • Provide clean air sources for positive pressure respirators to ensure the personal safety of operators in biosafety laboratories and toxic and harmful working areas.
   • Compressed air for breathing must meet the EN12021 Quality Standard for Compressed Air for Respiratory Use, with an oil content of ≤0.01mg/m³, a CO content of ≤5ppm, and a water vapor content of ≤-11℃ dew point.
2. Emergency escape support：
   • In emergency situations, the airtight door driven by compressed air can be quickly opened in 0.3 seconds, buying valuable time for evacuation.
   • Equipped with emergency breathing equipment, it can continuously supply gas for more than 30 minutes in emergencies such as power outages to ensure the safe evacuation of personnel.

3. Power source for precision processes

1. micro-environmental control：
   • Around precision instruments such as lithography machines and wafer inspection equipment, a micro-environment system driven by compressed air can maintain local cleanliness up to ISO 1 (Level 10) and a vibration value of ≤0.5μm.
   • The shockproof table using compressed air suspension technology can isolate external vibration interference and ensure nano-level processing accuracy.
2. Automated device drivers：
   • Provides clean power for pneumatic manipulators, vacuum cups and other actuators, and the repetitive positioning accuracy can reach ±0.005mm.
   • In ultra-precision manufacturing such as hard disk head assembly, compressed air-driven micro-displacement platforms can achieve nanoscale step control.

4. Supply of special process media

1. surface treatment applications：
   • In chip manufacturing, compressed air-driven plasma cleaning equipment can remove sub-nanometer pollutants on the wafer surface.
   • In the processing of optical elements, compressed air is mixed with abrasive to form aerosol to achieve ultra-smooth surface processing, with surface roughness Ra≤0.2nm.
2. Drying and cooling process：
   • In the lithium battery pole piece coating process, a suspension drying device driven by compressed air can make the residual solvent ≤0.05%.
   • In LED chip packaging, compressed air cooling technology is used to achieve rapid cooling at-40 ° C and reduce thermal stress defects.

5. System configuration specifications

1. Multi-stage purification system：
   • Equipped with a three-level purification device of pre-filter (5μm), precision filter (0.01μm), and activated carbon absorber to ensure that the cleanliness of compressed air reaches the ISO 8573-1 first-level standard.
   • In the biopharmaceutical clean room, a sterilization filter (0.001μm) needs to be added, and the sterilization efficiency is ≥99.9999%.
2. intelligent monitoring platform：
   • Monitor 12 parameters such as compressed air pressure, flow rate, dew point, and oil content in real time, and the data collection frequency is ≥1 time/second.
   • Set a three-level alarm threshold, start switching of alternate air sources within 10 seconds after exceeding the limit, and trigger sound and light alarms and text messages.
3. Pipeline system design：
   • The main air supply pipe is made of 316L stainless steel seamless pipe, with inner wall roughness ≤0.4μm, and the weld is subjected to electrolytic polishing.
   • The terminal branch pipe is equipped with an automatic drain valve to automatically discharge condensate every 2 hours to avoid the growth of microorganisms.

6. Operation and maintenance standards

1. Daily inspection requirements：
   • Check the exhaust temperature, pressure and oil level of the air compressor every 2 hours, and record the pressure change curve of the air storage tank.
   • Test the pressure difference of the end filter every day and replace the filter element immediately when it exceeds the initial value by 50%.
2. Annual testing items：
   • Carry out full testing on compressed air, including total microbial count, endotoxin content, VOCs concentration and other indicators.
   • Verify the tripping pressure of the safety valve, replace it immediately if the error exceeds ±3%, and conduct a pipeline pressure test.

It is recommended that enterprises establish a compressed air quality management system to implement full-process quality control from gas source equipment selection, pipeline construction acceptance to daily operation and maintenance. For continuous operation systems, an intelligent monitoring platform should be configured to achieve real-time monitoring and abnormal warning of key parameters such as pressure, flow, and purity to ensure that the clean room environment continues to be stable within the range of process requirements.