Laminar flow cabinet

A workbench or enclosure that provides a sterile environment using laminar air flow

A laminar flow cabinet, also known as a laminar flow hood or clean bench, 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.

Design and Function

Laminar flow cabinet in a microbiology department

The primary function of a laminar flow cabinet is to create a particle-free working environment by projecting air through a filtration system and exhausting it across a work surface in a laminar or unidirectional air stream. The air flow is designed to be uniform in both direction and speed, which helps to prevent cross-contamination.

Laminar flow cabinets are typically made of stainless steel with no gaps or joints where spores might collect. The air flow is usually vertical or horizontal, depending on the design and application. Vertical flow cabinets direct air from the top of the cabinet downwards, while horizontal flow cabinets direct air from the back of the cabinet towards the user.

Types of Laminar Flow Cabinets

There are two main types of laminar flow cabinets:

Horizontal Laminar Flow Cabinets

In horizontal laminar flow cabinets, air is drawn from the back of the cabinet and passed through a HEPA filter before being blown horizontally across the work surface towards the user. This type of cabinet is often used in applications where the risk of contamination from the user is minimal.

Vertical Laminar Flow Cabinets

Preparation of microbiological samples in a laminar chamber

Vertical laminar flow cabinets draw air from above the work area, pass it through a HEPA filter, and direct it downwards onto the work surface. This design is often preferred in applications where the risk of contamination from the user is higher, as the downward air flow helps to prevent contaminants from the user reaching the work surface.

Applications

Laminar flow cabinets are used in a variety of settings, including:

• Microbiology: To prevent contamination of samples and cultures.
• Pharmaceutical industry: For the preparation of sterile products.
• Electronics: To prevent contamination of sensitive components.
• Research laboratories: For any work requiring a clean environment.

Maintenance and Safety

Regular maintenance of laminar flow cabinets is crucial to ensure their effectiveness. This includes routine checks and replacement of HEPA filters, as well as cleaning of the work surfaces and interior surfaces of the cabinet. Users should also be trained in proper techniques to minimize contamination risks.

Related Pages

• HEPA filter
• Cleanroom
• Biological safety cabinet

File:Laminar Chamber Simple.jpg

Simple laminar chamber