There are three common types of airlocks: Cascade, Bubble, and Sink, often used in conjunction with air showers to minimize cross-contamination.
Types of Airlocks
Airlocks are crucial in environments where maintaining air quality and pressure differentials is important. They act as a buffer zone between areas with different cleanliness or pressure requirements. These airlocks can be combined with air showers for enhanced protection. Here's a breakdown of three common types:
| Type | Description | Air Pressure Relationship |
|---|---|---|
| Cascade | The airlock's pressure is graduated, usually decreasing from the cleanest area to the less clean area. | High pressure (clean area) -> Medium pressure (airlock) -> Low pressure (less clean area) |
| Bubble | The airlock maintains a higher pressure than both the clean and less clean areas. | High pressure (airlock) -> Low pressure (clean and less clean areas) |
| Sink | The airlock maintains a lower pressure than both the clean and less clean areas. This prevents air (and thus contaminants) from flowing from the airlock into either adjacent space. | High pressure (clean and less clean areas) -> Low pressure (airlock) |
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Cascade Airlocks: These airlocks are designed with a stepped pressure gradient. This ensures that air always flows from the cleanest area towards the less clean area, minimizing the risk of contamination flowing into the clean area.
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Bubble Airlocks: Bubble airlocks maintain a positive pressure relative to the surrounding areas. This means that if a door is opened, air rushes out of the airlock, preventing contaminants from entering either the cleaner or less clean areas.
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Sink Airlocks: Sink airlocks operate with negative pressure. This draws air into the airlock from both the cleaner and less clean areas, preventing contaminants from escaping the airlock. They're frequently employed when handling hazardous materials.
