Abstract: Apparatus for filtering air laden with dust or other particulate matter including: a filtering area, an air velocity dissipation zone above the filtering area, a lower tube sheet mounted above the dissipation zone and forming a partial boundary therewith, an air plenum mounted above the lower tube sheet, the air plenum including an air inlet for receiving dust laden air, an upper tube sheet forming an upper boundary of the air plenum, the lower tube sheet including a plurality of holes, the upper tube sheet including a plurality of holes vertically aligned with the holes in the lower tube sheet, a plurality of clean air outlet tubes having upper end, main body and lower end portions, the upper end portions being mounted within the holes in the upper tube sheet, the main body portions extending through the holes in the lower tube sheet, the lower end portions extending beneath the lower tube sheet and ending in a horizontal plane at the interface between the dissipation zone and the filtering area, a plurality