Abstract: A process chamber housing for an additive manufacturing apparatus comprising a process chamber with a bottom, a ceiling, and sidewalls jointly enclosing a volume of the process chamber, with a gas inlet in a front wall and a gas outlet in a rear wall of the sidewalls. The gas inlet and outlet are positioned at opposite sides of an opening in the bottom and face each other, which allows for an improved removal of smoke out of the process chamber if the gas inlet has a width wi, the opening has a width ws, and the gas outlet has a width w0, such that at least one of the relations (i) wi?ws±4 cm and wo?ws±4 cm; (ii) wi?ws and/or wo?ws; and (iii) wi?ws+1 cm and/or wo?ws+1 cm is satisfied.

Abstract: A process chamber housing for an additive manufacturing apparatus comprising a process chamber with a bottom, a ceiling, and sidewalls jointly enclosing a volume of the process chamber, with a gas inlet in a front wall and a gas outlet in a rear wall of the sidewalls. The gas inlet and outlet are positioned at opposite sides of an opening in the bottom and face each other, which allows for an improved removal of smoke out of the process chamber if the gas inlet has a width wi, the opening has a width ws, and the gas outlet has a width w0, such that at least one of the relations (i) wi?ws±4 cm and w0?ws±4 cm; (ii) wi?ws and/or w0?ws; and (iii) wi?ws+1 cm and/or w0?ws+1 cm is satisfied.

Abstract: An apparatus for producing a three-dimensional work piece is provided. The apparatus comprises a carrier configured to receive multiple layers of raw material powder, an irradiation unit configured to direct a radiation beam to predetermined in sites of an uppermost layer of the raw material powder in order to solidify the raw material powder at the predetermined sites, a process chamber defining a volume through which the radiation beam is directed from the Irradiation unit to the raw material powder, and a support structure provided outside the process chamber and supporting the irradiation unit.