Seal system

1. Seal system for an installation for producing a three-dimensional workpiece by means of an additive layer manufacturing method, the seal system comprising:

a first seal, which is configured to seal an intermediate space on a first periphery between a process chamber inner wall and a plate assembly supporting powder material in a process chamber of the installation, and

a second seal, which is configured to seal the intermediate space on a second periphery between the process chamber inner wall and the plate assembly supporting powder material in the process chamber of the installation,

the first seal and the second seal being mounted on the plate assembly and the first seal being spaced at a distance from the second seal in order to form, on sealing by the first seal and the second seal of the intermediate space between the process chamber inner wall and the plate assembly, a channel between the first seal and the second seal at an edge of the seal system for a gas to flow (i) along the channel in a circumferential direction around the plate assembly and/or (ii) substantially perpendicular to the circumferential direction of the channel.

2. Seal system according to claim 1 , the edge of the seal system comprising a circumferential edge of the seal system on which the channel is formed on sealing of the intermediate space.

3. Seal system according to claim 1 , further comprising a gas supply source, which is coupled to the channel formed on sealing of the intermediate space and is configured to supply a gas to the channel for generating a gas flow in the channel.

4. Seal system according to claim 1 , further comprising a gas extraction facility, which is coupled to the channel formed on sealing of the intermediate space and is configured to extract a gas from the channel for generating a gas flow in the channel.

5. Seal system according to claim 4 , further comprising a powder circuit, which is coupled to the gas extraction facility and/or the gas supply source and is configured to return powder material, which is located in the gas extracted by the gas extraction facility and/or in the gas pressed through the channel by the gas supply source, to a powder depot of the installation.

6. Seal system according to claim 3 , wherein the gas supply source is configured to generate the gas flow in the channel in the event of an upward movement of the plate assembly in the process chamber and/or during the production of the three-dimensional workpiece by means of the additive layer manufacturing method.

7. Seal system according to claim 1 , further comprising one or more pressure sensors, which are configured to detect a pressure in the channel, the seal system being configured to reduce a pressure difference between the pressure in the channel and an ambient pressure, in particular a pressure in the process chamber.

8. Seal system according to claim 7 , further comprising one or both of a gas supply source and a gas extraction facility, which are coupled to the channel formed on sealing of the intermediate space and configured to supply and/or extract a gas to/from the channel for generating a gas flow in the channel, the gas supply source and/or the gas extraction facility being configured to reduce the pressure difference based on the pressure in the channel and the ambient pressure.

9. Seal system according to claim 1 , further comprising one or more excess pressure connections and one or more vacuum connections, which are arranged such that on formation of the channel, the excess pressure connections and the vacuum connections are coupled to the channel such that excess pressure connections and vacuum connections alternate in the channel direction.

10. Seal system according to claim 9 , the excess pressure connections and the vacuum connections being coupled on formation of the channel to the channel such that spacings of respectively consecutive connections of the excess pressure connections and vacuum connections in the channel direction are of equal length.

11. Seal system according to claim 9 , further comprising one or more supply channels via which the one or more excess pressure connections and/or the one or more vacuum connections are coupled to the channel-formed on sealing of the intermediate space, a cross section of one of the supply channels narrowing before entry into an area between the first seal and the second seal and/or the supply channel fanning out.

12. Seal system according to claim 11 , further comprising a processor, which is configured to adjust a gas flow in the channel by means of the pressure sensors such that the pressure differences between channel and process chamber are minimised.

13. Seal system according to claim 1 , the first seal comprising a more wear-resistant material than the second seal.

14. Seal system according to claim 1 ,

wherein the plate assembly is movable upwards and/or downwards.

15. Installation for producing a three-dimensional workpiece by means of an additive layer manufacturing method, the installation comprising:

a system according to claim 14 ;

a process chamber, in which the system is arranged;

a powder depot for supplying powder material to the process chamber for producing the three-dimensional workpiece from the powder material by means of the additive layer manufacturing method, the powder depot being coupled to the seal system in order to supply powder material extracted by the seal system to the powder depot; and

an irradiation unit for irradiating a powder layer distributed on the plate assembly to produce the three-dimensional workpiece.

16. Installation according to claim 15 , further comprising one or more sensors, which are configured to detect a pressure in the process chamber and/or in the environment of the installation.