Air Shower Pass Box: Working Principle, Functions, and Applications

A Comprehensive Guide to Structure, Features, Applications, and Maintenance

I. Definition and Overview

An Air Shower Pass Box (also known as Air Shower Transfer Hatch) is a specialized cleanroom equipment designed for the transfer of materials between areas of different cleanliness levels. It integrates an air shower system and a pass box to remove particulate contamination from goods before entering a clean zone. Key terminology:

• HEPA = High-Efficiency Particulate Air filter
• ULPA = Ultra-Low Penetration Air filter
• GMP = Good Manufacturing Practice
• ISO 14644 = International standard for cleanrooms and associated controlled environments

II. Working Principle

The Air Shower Pass Box operates by using high-velocity filtered air to remove dust, microorganisms, and particles from the surface of materials being transferred.

• Air Circulation: Internal air is recirculated through a filtration system to maintain high cleanliness.
• Filtration System: Equipped with HEPA or ULPA filters to achieve filtration efficiency of ≥99.99% for particles ≥0.3µm.
• Anti-Cross-Contamination: Electronic or mechanical interlocking prevents both doors from opening simultaneously.
• Automatic Control: Programmable logic controllers (PLC) manage air shower duration, airflow velocity, and door locks.

III. Main Functions

• Minimizes cross-contamination between cleanroom zones.
• Ensures compliance with GMP and ISO 14644 cleanroom standards.
• Maintains stable cleanroom conditions.
• Improves production efficiency by integrating material transfer and decontamination.

IV. Structural Features and Materials

Air Shower Pass Boxes are manufactured with robust materials to ensure durability and hygiene:

• Stainless Steel (SS304 or SS316L) – corrosion-resistant, smooth finish for easy cleaning.
• Powder-Coated Cold-Rolled Steel – economical and durable.
• Aluminum Alloy – lightweight and corrosion-resistant.
• Tempered Glass – for observation windows.

V. Classification and Technical Parameters

Common configurations include single-side air shower pass boxes, double-side pass boxes, and custom sizes for large equipment.

VI. Typical Application Industries

• Cleanroom Engineering
• Medical Engineering
• Construction Engineering
• Laboratory Engineering & Equipment
• Medical Devices & Equipment
• Environmental Protection Technology
• Biotechnology

VII. Installation and Usage Notes

• Install according to ISO 14644-1: Cleanrooms and associated controlled environments requirements.
• Ensure proper grounding for electrical safety.
• Maintain unobstructed airflow paths.
• Follow GMP protocols during operation.

VIII. Maintenance and Care

• Clean internal surfaces daily with approved disinfectants.
• Replace pre-filters every 3–6 months, HEPA/ULPA filters every 12–18 months.
• Calibrate sensors and control systems annually.
• Inspect interlocking systems regularly.+