A filter door for closing a filter housing, in an industrial extraction system, wherein the filter door is fastened, with at least two locking elements relative to the housing surface wherein the filter door is pivotally arranged on one side by a slotted guide on the housing surface and is provided with a movable pivot axis. An industrial extraction system is also provided.

A pocket filter assembly (1) with reduced risk for exposing a user to contaminations leaving the pocket filter assembly during and after removal of the pocket filter assembly from an installation is disclosed. A first pocket filter (6a) comprises a grip member (10) configured to be gripped by the user to enable folding of the pocket filters in a controlled manner before removal of the pocket filter assembly from an installation.

The invention relates to a filter system designed for a containment (1) through which a gas flows, comprising at least one filter unit (2). First docking means (253) on the filter unit (2) are designed to removably connect the filter unit (2) to a receiving port (17) of the containment (1). The filter unit (2) further has a closure element (27) which can be adjusted by means of an adjusting mechanism (29) and which is used to block and open an entry (203) into the filter unit (2). In order to actuate the adjusting mechanism (29), a drive unit (3) which can be connected to the adjusting mechanism is provided. The connection between the adjusting mechanism (29) of the filter unit (2) and the drive unit (3) is also preferably designed to be dockable. The drive unit (3) has a motor (33) for driving a rotatably mounted transmission part (30), preferably in the form of an electric motor with a pinion or a gear. The transmission ratio of the motor (33) to the transmission part (30) is dimensioned so as to be greater than 1:20, preferably greater than 1:30, for example 1:33. In particular, when using a plurality of filter systems installed on a containment (1), a control unit is advantageous for switching and monitoring the position of all closure elements (27) according to a program. The adjusting mechanism (29) can also be actuated manually alternatively to the drive unit (3) which can be connected to the filter unit (2).

A filter unit for use in a filter box assembly, the filter unit comprising a particulate filter layer and a gas filter layer, the particulate filter layer being configured to bias towards the gas filter layer, exerting pressure thereon. There is also described filter box assemblies (including a duel filter assembly) comprising the filter unit, and a respiratory protective device comprising the filter unit. Also described is a method of manufacturing a filter unit with a gas filter layer and a particulate filter layer, wherein a force is applied to the particulate filter layer causing it to fix the gas filter layer in place. Also described is a method of manufacturing a dual filter assembly wherein a casing is twice reversibly attached to and detached from a support surface, filter units being added to the casing when the casing is attached to the surface.

This invention concerns an additive manufacturing apparatus for building a part by selectively consolidating flowable material in a layer-by-layer process comprising a build chamber (101) for building the part, a module (105, 106) for providing a focussed energy beam for consolidating flowable material in the build chamber, a gas flow circuit for generating a gas flow through the build chamber (101). At least one filter assembly (200, 201) may be arranged in the gas flow circuit, the or each filter assembly (200, 201) having associated therewith a valve (V-4, V-8) operable to seal the gas circuit upstream from the filter assembly (200, 201) and a valve (V-5, V-9) operable to seal the gas flow circuit downstream of the filter assembly (200, 201), the arrangement allowing a filter element (E-5, E-7) of the filter assembly (200, 201) to be changed whilst maintaining a controlled atmosphere in the build chamber (101). The apparatus may further comprise a purging device (210) configured to purge air from the or each filter assembly (200, 201) when the valves (V-4, V-5; V-8, V-9) associated with that filter assembly (200, 201) have sealed the filter assembly (200, 201) from the gas flow. Alternatively or additionally, a controller (131) may be arranged to control the valves (V-4, V-5; V-8, V-9) associated with the or each filter assembly (200, 201) such that the filter assemblies (200, 201) are closed off to gas flow from the build chamber (101) during a period in which the inert gas atmosphere in the build chamber (101) is compromised as a result of opening the door to the build chamber (101). The apparatus may comprise a pair of filter assemblies (200, 201) arranged in parallel within the gas flow circuit, the arrangement allowing a filter element (E-5, E-7) of the each filter assembly (200, 201) to be changed during a build by allowing the filter element (E-5, E-7) of one filter assembly (200, 201) to be changed whilst the filter element (E-5, E-7) of the other filter assembly (200, 201) is connected to filter particulates from the gas flow. A monitoring device (I-3, I-5) may be provided for detecting a property associated with the gas flow and a controller (131) arranged to control the valves to switch the filter assembly (200, 201) connected in line with the gas flow based upon signals from the monitoring device (I-3, I-5