Laminar flow hood

Laminar flow hood

A laminar flow hood, also known as a laminar flow cabinet or laminar flow workstation, is a carefully enclosed bench designed to prevent contamination of semiconductor wafers, biological samples, or any particle sensitive materials. Air is drawn through a HEPA filter and blown in a very smooth, laminar flow towards the user. The principle behind the laminar flow hood is to provide a workspace that has a unidirectional flow of air that traps particles and ensures a contamination-free environment.

Principles of Operation

The operation of a laminar flow hood is based on the principle of laminar flow. Laminar flow refers to a consistent flow of air in one direction at the same speed, with minimal or no cross-over of air streams (or "turbulence"). This is achieved by passing air through a HEPA filter to remove 99.99% of particles larger than 0.3 micrometers from the air. The filtered air is then passed through the cabinet in a laminar or unidirectional flow to protect the work from contamination.

Types of Laminar Flow Hoods

There are two main types of laminar flow hoods: horizontal and vertical.

• Horizontal Laminar Flow Hoods: In these hoods, the filtered air flows directly at the user from the back of the cabinet. They are commonly used for work that requires a clean work area but not necessarily a sterile environment.

• Vertical Laminar Flow Hoods: In vertical laminar flow hoods, the air comes from above and is blown downwards onto the work surface. These are preferred in applications where sterility is a priority, such as in the preparation of culture media in microbiology.

Applications

Laminar flow hoods are used in a variety of settings, including research laboratories, hospitals, and manufacturing facilities. Their applications include:

• Preparation of pharmaceutical products
• Sterile handling in microbiology
• Assembly of electronic components
• Any application requiring a dust and particle-free environment

Maintenance

Regular maintenance of a laminar flow hood is crucial for its effective operation. This includes:

• Regular testing and replacement of the HEPA filters
• Cleaning the interior surfaces with appropriate disinfectants
• Calibration and certification by a professional to ensure proper airflow and filter performance

Safety Considerations

While laminar flow hoods protect the work from contamination, they do not provide protection to the user from harmful aerosols or chemicals. Therefore, it's important to use appropriate personal protective equipment (PPE) and follow safety protocols.

See Also

• Cleanroom
• HEPA filter
• Biosafety cabinet

External Links

• CDC - Cleanrooms and Controlled Environments

Laminar flow hood Resources
Latest articles Most recent articles Ongoing trials	Wikipedia