Filtering unit with improved cover assembly

A filtering unit comprising:

• a filtering component having an inner wall, an outer wall arranged around the inner wall so as to define an inner space between the inner wall and the outer wall, and a filtering medium partitioning the inner space into a pre-filter chamber and a post-filter chamber, at least said pre-filter chamber being circumferentially compartmented in sectors, at least one of said inner wall and said outer wall having passages respectively communicating with corresponding ones of the sectors,
• a divider arranged coaxially with the filtering component, the divider having distinct distribution columns;
• a cover arranged at an axial end of the filtering component;
• a rotary backwashing distributor having a shutter provided with a discharge opening, the rotary backwashing distributor being mounted to rotate so that said discharge opening is periodically and selectively put into communication with each distribution column, whereby each distribution column periodically and selectively establishes communication between the discharge opening and respective ones of the passages;
• and
• a dividing plate arranged between the cover and the rotary backwashing distributor, the dividing plate being detachably secured with respect to the cover and having apertures opening into the distribution columns,
• wherein the shutter abuts a contact surface of the dividing plate at least on a closed contour surrounding the discharge opening.