Pocket filter assembly

A pocket filter assembly for removing contaminants, the pocket filter assembly including a frame structure having a plurality of filter pocket openings and a corresponding plurality of filter pockets, each filter pocket having a pocket mouth sealed in a corresponding filter pocket opening, wherein

• the frame structure includes an outer subframe and a corresponding inner subframe, the outer and inner subframes being connected and locked to each other by locking elements at a plurality of locking positions along two longitudinal sides of each filter pocket opening and along opening portions of the subframes defining the filter pocket openings, the outer subframe being hollow and the inner subframe being received within the hollow outer subframe;
• the filter pocket mouths are clamped and sealed between co-operating opening portions of the subframes, the clamped portions of the filter pocket mouths extending in a direction of air or gas flow through the corresponding filter pocket opening;
• and
• said locking elements, at each locking position on said co-operating opening portions of the subframes, include a projection on one of the subframes and a co-operating receiving aperture on the other of the subframes such that an interlock of the subframes to each other is obtained, a filter pocket mouth material of the associated filter pocket being between said projection and said receiving aperture such that said interlock is sealed thereby.