Laminar air flow

Introduction
• Many medical and research facilities require aseptic working environment to carry out specialized work
• Laminar air flow Can maintain such aseptic area which is devoid of contaminants
Principle
• Create particle free working environment
• By projecting air through a filtration system
• And exhausting it across a work surface
• With uniform velocity along parallel flow lines
Construction
• Aseptic cabinet- made up of stainless steal without gaps and joints
• Air blower- produces air flow
• Special Filtration system- Pre-filter and HEPA-filter (high efficiency particulate air filter)
      • Pre-filter- removes course particles to prevent clogging of HEPA filter
      • HEPA-filter- can remove particles of size 0.3 µm or more with 99.9% efficiency
• Fluorescent tube- to light up the aseptic cabinet
• UV lamp- to kill the microorganisms already present inside the aseptic cabinet
Working
• Dust particles are removed from the surface with smooth cloth soaked in alcohol
• UV lamp is switched on for 30 minutes to kill microbes already present inside cabinet
• Front covering is opened to keep desired material inside
• Air blower is switched on
• Air is allowed to pass through the filter into aseptic cabinet at a constant velocity
• This mechanism doesn’t allow any kind of microbe to enter into cabinet
• Person can sit properly in front of the cabinet
• All the work like pouring, plating, streaking etc can be carried out inside the aseptic cabinet
Types
Depending upon the direction of flow of air, laminar air flow unit can be divided into two basic types-
1. Horizontal type- air enters the aseptic cabinet horizontally
2. vertical type- air enters the aseptic cabinet vertically from upward to downward

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