Powder removal assemblies and methods of removing unbound particles using powder removal assemblies

A powder removal assembly for removing powder from a part produced by additive manufacturing, comprising:

• a process chamber including an outlet;
• a recovery chute defining a flow path from the outlet of the process chamber to a powder recovery chamber;
• an elevator that selectively extends and retracts into and out of the process chamber through an inlet defining an inlet axis;
• a nozzle rotatably coupled to the process chamber and configured to remove particles from the process chamber, the nozzle being positioned to direct a fluid towards a cake including the part, the nozzle being rotatable about the inlet axis;
• a particle sensor coupled to the outlet to determine an amount of particles falling under the force of gravity as a function of time, the particle sensor positioned along the flow path and adjacent to the outlet of the process chamber;
• and
• a control system communicatively coupled to the particle sensor and the nozzle, the control system being configured to automatically activate and deactivate the nozzle in response to a change in a rate of the amount of particles passing through the outlet as a function of time, passing a threshold value.