A filtering system for a flow of dust-laden gas, comprising a fabric filter enclosure having at least one inlet opening, a gas plenum having a first main flow direction and at least one gas outlet opening in a vertical side wall of the gas plenum for feeding the dust-laden gas to the fabric filter enclosure, and an inlet channel from the at least one outlet opening to the at least one inlet opening, the inlet channel having a substantially horizontal second main flow direction differing from the first main flow direction, an inner surface, and a gas flow control device, wherein the gas flow control device comprises - a damper blade arranged in the inlet channel and having a general plane and two opposite, substantially planar surfaces (56, 58) with a shape fitted to enable closing of the inlet channel, and two opposite end edges (60, 60'), the damper blade being arranged to be pivoted through a definite pivoting angle around a substantially horizontal pivot axis, wherein the pivot axis is perpendicular to the second main flow direction and passes adjacent to the end edges (60, 60') of the damper blade so as to divide the damper blade to two end sections (76, 76'), for regulating the flow of the dust-laden gas in the inlet channel by pivoting the damper blade between an open position, wherein the general plane of the damper blade is parallel to the second main flow direction, and a closed position, characterized in that the gas flow control device comprises - at least one substantially planar guide baffle (48, 48') attached to each of the two substantially planar surfaces of the damper blade at a distance from the end edges (60, 60') of the damper blade, the at least one guide baffle extending in the open position of the damper blade substantially parallel to the second main flow direction and from the pivot axis in the direction of the normal of the general plane of the damper blade substantially to an opposite inner surface (64, 66) of the inlet channel, for controlling the distribution of the dust-laden gas flow to the fabric filter enclosure. - a damper blade arranged in the inlet channel and having a general plane and two opposite, substantially planar surfaces (56, 58) with a shape fitted to enable closing of the inlet channel, and two opposite end edges (60, 60'), the damper blade being arranged to be pivoted through a definite pivoting angle around a substantially horizontal pivot axis, wherein the pivot axis is perpendicular to the second main flow direction and passes adjacent to the end edges (60, 60') of the damper blade so as to divide the damper blade to two end sections (76, 76'), for regulating the flow of the dust-laden gas in the inlet channel by pivoting the damper blade between an open position, wherein the general plane of the damper blade is parallel to the second main flow direction, and a closed position, characterized in that the gas flow control device comprises - at least one substantially planar guide baffle (48, 48') attached to each of the two substantially planar surfaces of the damper blade at a distance from the end edges (60, 60') of the damper blade, the at least one guide baffle extending in the open position of the damper blade substantially parallel to the second main flow direction and from the pivot axis in the direction of the normal of the general plane of the damper blade substantially to an opposite inner surface (64, 66) of the inlet channel, for controlling the distribution of the dust-laden gas flow to the fabric filter enclosure.