‌Cleanroom Laminar Flow Cabinet‌

A laminar flow cabinet (LFC) is an air purification device designed to provide a high-cleanliness environment for localized operational areas. Its core function lies in generating a stable air barrier through an efficient filtration system to ensure contamination control. Below is a detailed analysis of its structure, technical principles, classifications, and applications:

‌I. Core Structure and Technical Principles‌

1. ‌Air Handling Process‌
   The laminar flow cabinet draws ambient air via a fan, which is first filtered through a pre-filter (primary/medium efficiency) to trap large particulate pollutants. The air is then equalized in a plenum chamber and undergoes secondary filtration via a HEPA filter (High-Efficiency Particulate Air, ≥99.97% efficiency for particles ≥0.3μm). Finally, the purified air is discharged as vertical or horizontal laminar flow, creating an ISO Class 5 (Class 100) clean environment

   • ‌Vertical Laminar Flow‌: Airflows downward from the top, ideal for pharmaceutical or biological applications requiring operator protection
   • ‌Horizontal Laminar Flow‌: Airflows horizontally from front to back, with lower noise levels, commonly used in electronics or low-interference scenarios

2. ‌Key Components‌
   Includes a fan, pre-filter, HEPA filter, plenum chamber, UV lamp (for surface sterilization), and differential pressure monitoring system

‌II. Classifications and Selection Guidelines‌

1. ‌By Airflow Direction‌

   • ‌Vertical Flow‌: Fan located at the top; higher noise but uniform coverage, suitable for aseptic operations (e.g., cell culture, pharmaceuticals)
   • ‌Horizontal Flow‌: Parallel airflow with lower noise, ideal for electronics assembly or precision instrument handling

2. ‌By Operational Design‌

   • ‌Single/Double-Sided Operation‌: Choose based on workspace requirements (single or dual operators)
   • ‌Recirculating Type‌: Suitable for non-cleanroom environments but requires frequent filter replacement

3. ‌By Application‌

   • ‌General Type‌: For generic use (electronics, optics).
   • ‌Biosafety Type‌: Equipped with negative pressure systems or biological containment, used for handling pathogens (distinct from biosafety cabinets)

‌III. Applications and Advantages‌

1. ‌Key Fields‌

   • ‌Biopharmaceuticals‌: Aseptic preparation, cell culture
   • ‌Electronics Manufacturing‌: Precision component assembly, chip production
   • ‌Scientific Research‌: Microbiology, materials science experiments

2. ‌Core Benefits‌

   • Maintains localized ISO Class 5 cleanliness, minimizing contamination risks
   • Enhances experimental reproducibility and product yield
   • Flexible configurations (mobile or integrated into production lines)

‌IV. Operational Standards and Maintenance‌

1. ‌Operational Protocols‌

   • Sterilize surfaces with UV light for 30 minutes before use; pre-run the fan for 20 minutes
   • Avoid blocking air inlets (rear or lower sections); clean pre-filters regularly (e.g., foam pads)

2. ‌Maintenance Requirements‌

   • Monitor HEPA filter pressure drop; replace when airflow velocity drops below 0.3 m/s
   • Wipe surfaces and interior walls with 70% ethanol or phenol solution periodically
   • Ensure proper grounding for three-phase power to prevent motor damage

‌V. Differentiation from Biosafety Cabinets‌

Laminar flow cabinets operate under ‌positive pressure‌, protecting only samples from contamination. In contrast, biosafety cabinets use ‌negative pressure‌ to safeguard operators, samples, and the environment. Biosafety cabinets are mandatory when handling biohazardous materials.