01 Physical Mechanisms and Damage Models of Microscopic Pollutants
The common need for air cleanliness in gas turbines and semiconductor manufacturing facilities stems from deterministic failure mechanisms caused by microscopic pollutants in different physical and chemical environments.
In gas turbine systems, submicron to micron-sized particles in the intake air (mainly composed of hard minerals such as SiO₂ and Al₂O₃) undergo an adiabatic compression process in the compressor stage and then enter the combustion chamber at a speed of 200-300 meters per second. In the high-temperature environment of 1400-1600°C, these particles undergo phase transition and melting, and adhere to the surface of the turbine blades through inertial deposition. According to research data from Trenntech at the Hamburg Technology Center, when the concentration of hard particles with a particle size >2μm in the intake air exceeds 3μg/m³, the probability of cooling hole blockage in the first-stage turbine blades will increase by 47%, leading to an increase in blade metal temperature of 80-120°C, directly reducing the service life of high-temperature components.
In semiconductor manufacturing, the scale of pollutant effects decreases by three orders of magnitude. When the chip manufacturing process reaches the 5-nanometer node, particles larger than 10 nanometers can cause pattern defects. More critically, there is the influence mechanism of molecular contaminants (AMC): for example, ammonia (NH₃) will undergo photochemical interaction with the photoresist during the 193nm photolithography process, forming an interfacial reaction layer ≤5nm thick, resulting in line width deviations exceeding 15% of the design specifications. Although these two failure mechanisms differ in scale, they both follow a deterministic relationship between pollutant concentration, exposure time, and damage degree, forming the basis for the design of ultra-clean air systems.
02 Quantitative Comparison and Engineering Logic of Industrial Cleanliness Standards
The gas turbine field follows the ISO 29461-1:2017 standard, which uses mass concentration as the main control indicator and pays particular attention to particle size distribution characteristics. Typical heavy-duty gas turbine requirements: For 99.9% of operating time, the mass concentration of particles with a size of 2-10 μm must be <5 μg/m³, with hard particles (Mohs hardness ≥6) accounting for <30%. The core engineering logic of this standard lies in controlling the cumulative mass flux, ensuring continuous operation reliability for 30,000 hours by keeping blade deposits below a critical thickness (usually <50 μm).
Semiconductor cleanrooms adhere to the particle number concentration standards of ISO 14644-1:2015. EUV lithography areas require ISO Class 1 cleanliness, while also meeting the limitations on molecular contaminants specified in the SEMI F21-1102 standard. The engineering logic behind this dual control system is the exponential relationship between defect density and yield: when the concentration of 0.1 μm particles increases from 10 particles/m³ to 100 particles/m³, the chip yield for a 28 nm process will decrease by 12-18%.
03 Differentiated Technological Paths of HEPA/ULPA Filtration Systems
Gas turbine intake filtration systems employ a multi-stage progressive design: the first stage is an inertial separator, removing over 98% of particles >10 μm; the second stage is a pulse self-cleaning bag filter, handling 1-10 μm particles; and the third stage is a weather-resistant HEPA filter (H13 class according to EN1822 standard), which uses hydrophobic and moisture-resistant glass fiber material, maintaining structural integrity even at 100% relative humidity.
Semiconductor cleanrooms use a completely different technological path: their ULPA filters (U15 class and above) must achieve a filtration efficiency of 99.9995% @ 0.12 μm and must be integrated with chemical filters. Advanced systems use a sandwich structure: the front layer is activated alumina impregnated with phosphoric acid, specifically designed to remove alkaline AMC; the middle layer is an ULPA ultra-fine glass fiber membrane; and the back layer is a honeycomb ceramic loaded with transition metal oxides, used for catalytic decomposition of organic matter.
Whether it’s the gas turbines powering cities or the cleanrooms used for chip manufacturing, their exceptional performance is built on the same foundation: absolute control over ultrafine particles in the air. HEPA/ULPA filtration technology, based on the same physical principles, provides a definitive microscopic barrier for both of these major industrial sectors. Although different standards and technological approaches have emerged due to differing objectives—the former pursuing long-term reliability in extreme environments, the latter demanding atomic-scale static purity—this exemplifies the essence of engineering: transforming universal scientific principles into precise solutions for specific extreme conditions. The continuous evolution of this fundamental technology silently supports humanity’s eternal pursuit of more powerful energy and more precise manufacturing.