In hypoxia, how to deal with the hypoxic vacuum area can be referred to as follows:
A water gate can be built outside the vacuum area (as shown in the picture below), and the vacuum area can then be treated.
Because the four lower compartments inside the water gate are all occupied by liquid, they can isolate the air, so the gases inside and outside the water gate will not be exchanged. In this way, the vacuum area can be treated without causing gas to flow into the vacuum area.
This method can also be used to vacuum the area inside the water gate with an air pump.