The disclosure relates to a filtration device that comprises a disc with a rim covering and stiffening a plurality of filtration sectors connected to taps provided on the outer wall of a rotary main shaft containing inner discharge channels and fit-inserted into said taps and into a crown comprising two parts concentric to the shaft, one which is secured to the shaft while the other is removable, characterised in that said rim is provided with openings each intended for receiving a removable connection flange bearing, on the one hand, a radial strut clamped between two adjacent sectors for the relative clamping thereof and interacting, on the other hand, with a spring quick fastener for locking the strut under tension between the sectors. The disclosure also relates to a method for assembling and maintaining said filtration device.