Airlock (untested)

thingiverse

Airlock used to prevent overpressure in fermentation containers for beer & wine or contamination from air exposure for certain biology experiments. Water is slowly added to the outer chamber and flows into the inner chamber thus preventing ambient air from entering the container through the center pipe. Gas buildup in the fermentation container flows up the center pipe causing the water level in the inner chamber to lower until the gas can escape through the holes at its base into the outer chamber. Once there, the gas will rise through the outer chamber and escape through the side vents near the top. To prevent dust from making the water in the airlock muddy while still allowing for the monitoring of gas activity and water level, cover the top with a clear material such as a piece of clear packing tape. I've designed a simple lid with .4mm clearance to fit loosely enough to be removed without disturbing the airlock. Print this part in clear to easily monitor gas activity. Check the water level in the airlock daily and refill it when needed. When refilling, excess water should escape from the side vents rather than draining into the fermentation container.