Filter assembly

A method of changing a particle filter element located within a filter housing mounted on an additive manufacturing apparatus, the additive manufacturing apparatus comprising:

• a build chamber,
• a module for providing a focused energy beam for consolidating layer-by-layer powder material in the build chamber to build an article,
• a gas flow circuit for passing a flow of gas through the build chamber during the manufacturing process, and
• a filter assembly comprising:
• the filter housing having a gas inlet and a gas outlet,
• a first valve actuatable to seal the gas inlet, and
• a second valve actuatable to seal the gas outlet,
• wherein the gas inlet and gas outlet are detachably coupled to the gas flow circuit such that the filter assembly is removably-mounted to the additive manufacturing apparatus and permit gas flow through the filter housing from the gas inlet to the gas outlet such that the filter element is configured to filter at least one of volatile and explosive powder from the gas of the gas flow circuit,
• the method comprising, in order:
• (a) closing the first valve to seal the gas inlet to the filter housing and closing the second valve to seal the gas outlet from the filter housing,
• (b) removing the filter assembly from the additive manufacturing apparatus,
• (c) connecting a source of liquid to the filter housing to flood the filter housing to entrap the at least one of volatile and explosive powder held against the filter element, and
• (d) opening the filter housing to remove the filter element, against which the at least one of volatile and explosive powder has been entrapped by the liquid, from the filter housing.

A method of changing a particle filter element located within a filter housing mounted on an additive manufacturing apparatus, the additive manufacturing apparatus comprising:

• a build chamber,
• a module for providing a focused energy beam for consolidating layer-by-layer powder material in the build chamber to build an article,
• a gas flow circuit for passing a flow of gas through the build chamber during the manufacturing process, and
• first and second filter assemblies, each of the first and second filter assemblies comprising:
• a filter housing having a gas inlet and a gas outlet, and
• the particle filter element located within the filter housing between the gas inlet and the gas outlet and configured to filter at least one of volatile and explosive powder from the gas of the gas flow circuit,
• wherein, the first and second filter assemblies are arranged in parallel in the gas flow circuit of the apparatus,
• the method comprising:
• for one of the first and second filter assemblies, providing a neutralised particle filter element by trapping the at least one of volatile and explosive powder held on the filter element to neutralise the at least one of volatile and explosive powder, and
• removing the neutralised particle filter element from the filter housing during operation of the additive manufacturing apparatus, wherein during removal of the neutralised filter element, the other of the first and second filter assemblies is used to filter the at least one of volatile and explosive powder from the gas of the gas flow circuit.

An additive manufacturing apparatus comprising:

• a build chamber,
• a module for providing a focused energy beam for consolidating layer-by-layer powder material in the build chamber to build an article,
• a gas flow circuit for passing a flow of gas through the build chamber during the manufacturing process and a filter assembly, the filter assembly comprising:
• a filter housing having a gas inlet and a gas outlet detachably coupled to the gas flow circuit,
• a particulate filter element located within the filter housing between the gas inlet and the gas outlet and configured to filter at least one of volatile and explosive powder from the gas of the gas flow circuit,
• a valve actuatable to seal the gas inlet, and
• a valve actuatable to seal the gas outlet,
• wherein the filter housing is configured to allow ingress of fluid into the filter housing for entrapping the at least one of volatile and explosive powder held on the particulate filter element to provide a neutralized particulate filter element and openable to allow direct access to the neutralized particulate filter element, on which the at least one of volatile and explosive powder is entrapped by the fluid, for removal of the neutralized particular filter element from the filter housing.

A method of changing a particle filter element located within a filter housing mounted on an additive manufacturing apparatus, the additive manufacturing apparatus comprising:

• a build chamber,
• a module for providing a focused energy beam for consolidating layer-by-layer powder material in the build chamber to build an article,
• a gas flow circuit for passing a flow of gas through the build chamber during the manufacturing process, and
• a filter assembly comprising:
• a filter housing having a gas inlet and a gas outlet, and
• a particulate filter element located within the filter housing between the gas inlet and the gas outlet and configured to filter at least one of volatile and explosive powder from the gas of the gas flow circuit,
• the method comprising:
• providing a neutralised filter element by entrapping the at least one of volatile and explosive powder held on the particulate filter element in a fluid to neutralise the at least one of volatile and explosive powder, and
• removing the neutralised particulate filter element, on which the at least one of volatile and explosive powder is entrapped by the fluid, from the filter housing.

An additive manufacturing apparatus comprising:

• a build chamber,
• a module for providing a focused energy beam for consolidating layer-by-layer powder material in the build chamber to build an article,
• a gas flow circuit for passing a flow of gas through the build chamber during the manufacturing process, and
• a filter assembly comprising:
• a filter housing having a gas inlet and a gas outlet detachably coupled to the gas flow circuit such that the filter assembly is removably-mountable to the additive manufacturing apparatus,
• a particulate filter element located within the filter housing between the gas inlet and the gas outlet and configured to filter at least one of volatile and explosive powder from the gas of the gas flow circuit,
• a first valve actuatable to seal the gas inlet, and
• a second valve actuatable to seal the gas outlet,
• wherein the filter assembly is removable with the gas inlet sealed by the first valve and the gas outlet sealed by the second valve such that the particulate filter element is sealed from exposure to air within the filter housing.