Europe · Upgrade of Class 0 Oil-Free Ultra-Clean Compressed Air System for PV Wafer Manufacturing Base

Project Background: A large-scale silicon wafer and solar cell manufacturing base in Europe covers silicon ingot cutting, diamond wire slicing, wet cleaning, PECVD coating, screen printing and lamination. Compressed air is widely used for wafer purging, pneumatic manipulators, powder conveying, chamber exchange and fixture actuation. PV manufacturing has strict requirements for air purity. Even trace oil mist, moisture or suspended particles can cause coating defects, cell microcracks, poor grid printing and lamination bubbles, directly hurting product yield.

The original system adopted oil-injected screw compressors with multi-stage oil removal filters. Though temporarily compliant, filter media faced oil vapor penetration risk, leading to high recurring consumable cost. Production runs intermittently with full load during daytime and partial shutdown at night. Fixed-speed units poorly matched variable load and suffered heavy idle loss. Tightening EU carbon regulations pushed the plant to cut utility energy consumption. Old units generated excessive noise exceeding cleanroom limits, and lacked centralized traceability monitoring. Once air contamination occurred, engineers struggled to locate root causes quickly, failing audit requirements for new energy factories.

Solution: Multiple dry-type oil-free screw compressors were deployed for centralized air supply, certified ISO 8573-1 Class 0 to eliminate oil contamination at source. Twin-tower adsorption dryers stabilize pressure dew point below -70℃, followed by ULPA filters to intercept submicron particles. Electropolished stainless steel piping reduces particle accumulation on inner walls. An intelligent joint control platform connects to the factory MES system to adjust loading sequence according to production signals, putting redundant units into sleep mode during low-load periods. Waste heat from compression is recovered for hot water supply in cleaning processes. Acoustic enclosures and vibration dampers are installed for noise control. Real-time sensors track oil content, dew point, particle count, pressure and flow, automatically generating audit-ready trace logs.

Results: Zero oil contamination risk is secured after retrofit. Air-related defects on solar cells drop sharply and yield improves. Intelligent load regulation eliminates idle energy waste, cutting power consumption of compressor station by roughly 24%. Combined with waste heat recovery, purchased heat demand for factory processes is reduced. Pressure fluctuation is controlled within ±0.02MPa, meeting precision requirements of screen printing and coating. Full traceability of air quality helps pass EU clean manufacturing audits. Redundant layout prevents unplanned shutdown and supports 24/7 continuous production, forming a benchmark for Class 0 air station construction for European PV expansion projects.