Humidification in a build material recovery system

1. A build material recovery system for additive manufacturing, the system consisting of:

a receiving station to receive a portable container containing a build material;

a separator to remove build material from a stream of air;

a first conduit to carry build material in the stream of air from the receiving station to the separator;

a source of negative air pressure to pull the stream of air with the build material through the first conduit from the receiving station to the separator;

a humidifier to add moisture to the stream of air;

a second conduit to carry build material from the separator to the receiving station; and

optionally, the portable container to contain the build material for additive manufacturing.

2. The system of claim 1 , where the humidifier is to add moisture to the stream of air in the first conduit.

3. The system of claim 1 , where:

the receiving station includes an unloading port through which build material powder may be recovered from a container in the receiving station and a loading port through which build material powder may be added to a container in the receiving station;

the first conduit is to carry build material in the stream of air from the unloading port to the separator;

the second conduit is to carry build material from the separator to the loading port; and

the humidifier is to add moisture to the stream of air entering the unloading port at the receiving station and/or to build material in the second conduit.

4. The system of claim 1 , where the humidifier is to add moisture to build material in the separator.

5. The system of claim 1 , where the humidifier is to add moisture to the stream of air in the first conduit and to build material in the separator.