Abstract: A method for recirculating powder in an apparatus for manufacturing a three-dimensional object from the powder. The powder recirculation method includes: providing powder in a powder repository, the powder being one of fresh powder, excess powder or a blend thereof; transferring the powder from the repository to a work surface; distributing the powder across a build surface and resulting in a portion of the powder defining excess powder; returning the excess powder back to the repository; monitoring the amount of powder in the repository relative to a predetermined amount of powder; and delivering fresh powder from a powder tank to the repository when the amount of powder in the repository is less than the predetermined amount and not delivering fresh powder when excess powder is being returned to repository and the amount of powder in the repository is greater than the predetermined amount of powder.

Abstract: A powder recirculation system for an apparatus for manufacturing a three-dimensional object (500) from powder is provided. The powder recirculation system comprises: a delivery path coupled to an outlet of a powder tank (410), the powder tank configured to store the powder; a powder repository (115) coupled to an outlet of the delivery path, the delivery path comprising a delivery mechanism for delivering the powder from the powder tank to the powder repository; a powder recirculation path coupled to an outlet (102) of the powder repository, wherein the powder recirculation path is configured to return first excess powder from the powder repository to the delivery path at a location (103, 104) upstream of the outlet of the powder tank.

Abstract: A powder recirculation system for an apparatus for manufacturing a three-dimensional object (500) from powder is provided. The powder recirculation system comprises: a delivery path coupled to an outlet of a powder tank (410), the powder tank configured to store the powder; a powder repository (115) coupled to an outlet of the delivery path, the delivery path comprising a delivery mechanism for delivering the powder from the powder tank to the powder repository; a powder recirculation path coupled to an outlet (102) of the powder repository, wherein the powder recirculation path is configured to return first excess powder from the powder repository to the delivery path at a location (103, 104) upstream of the outlet of the powder tank.