Abstract: A device for detachably securing a dust filter bag in dust aspirating equipment, comprises a flange part of rigid material seated externally on the bag wall and having a passage opening aligned with an inlet opening in the bag wall, and an equipment specific adapter plate of rigid material, which on the one hand is able to be secured to the dust aspirating equipment and on the other hand is able to be detachably connected with the flange part by means of a plug and detent joint. The adapter plate has a through opening which in the connected state is flush with the passage opening in the flange part and together with same has a through opening constituting a flow opening with the same and an annular seal and in the connected state effective between the adapter plate and the flange part for sealing off the through opening from the outside.

Abstract: The invention describes a multi-layer filter structure and the use of a multi-layer filter structure for the dust removal from gases, wherein a coarse dust filter layer, a fine dust filter layer, and a support layer are disposed behind one another in the direction from the inflow side to the outflow side, and which is designed such that the fiber diameter distribution within the coarse dust filter layer and fine dust filter layer has a gradient, and that the fiber diameters of the coarse dust filter layer and fine dust filter layer continually decrease from the inflow side to the outflow side. This multi-layer filter structure may be used in a filter cassette for industrial dust removal, as well as in a stationary or mobile home dust cleaning device.