Apparatus and method for producing a three-dimensional work piece comprising a flow trap

An apparatus for producing a three-dimensional work piece, the apparatus comprising:

• a process chamber,
• a carrier configured to receive a raw material powder,
• an irradiation device configured to selectively irradiate electromagnetic or particle radiation onto the raw material powder on the carrier in order to produce a work piece made of said raw material powder by an additive layer construction method,
• a transmission element configured to allow the transmission of the electromagnetic or particle radiation emitted by the irradiation device into the process chamber,
• a gas supply device configured to supply gas to the process chamber and comprising at least one gas inlet,
• a gas discharge device configured to discharge gas from the process chamber and comprising at least one gas outlet, and
• a flow trap configured to trap gas containing particulate impurities in a flow trap region which, with respect to a direction of flow of the gas entering the process chamber via the at least one gas inlet, is arranged downstream of the transmission element.

A method for producing a three-dimensional work piece, the method comprising:

• applying a layer of raw material powder onto a carrier,
• selectively irradiating electromagnetic or particle radiation onto the raw material powder on the carrier in order to produce a work piece made of said raw material powder by an additive layer construction method,
• transmitting the electromagnetic or particle radiation into a process chamber via a transmission element,
• supplying gas to the process chamber via at least one gas inlet of a gas supply device,
• discharging gas from the process chamber via at least on gas outlet of a gas discharge device, and
• by means of a flow trap, trapping gas containing particulate impurities in a flow trap region which, with respect to a direction of flow of the gas entering the process chamber via the at least one gas inlet, is arranged downstream of the transmission element.