Patent ID: 7776117

Claim:
An air filtration plant, comprising: a filter cartridge fitted with filter sleeves, said sleeves are arranged vertically, and held stretched by appropriate stretching means between two supporting structures, a closed lower end of said sleeves being attached to a lower one of said two supporting structures by a first fastener, and an open upper end of said sleeves being attached to openings provided in an upper supporting structure of said two supporting structures, by a second fastener, said upper supporting structure being in the form of a plate fitted with said openings, wherein the upper end of the sleeves is fitted with a structural element that increases the grip thereof, manually or mechanically, wherein the stretching means fasten the filter sleeves and are configured to enable tensioning of said sleeves at the upper ends thereof, and wherein said second fastener comprises a separate add-on member that is configured to be located within said sleeves below said upper end when the sleeves have been attached to the lower supporting structure and have been stretched to a stretched position, said add-on member being configured to hold said sleeves in said stretched position by clamping against an internal contour of the openings of the upper supporting structure.