| 摘要 |
<p>An air filtering arrangement comprises a generally cylindrical, rotary, perforate filter element (29), a fan (18) operable to draw air therethrough, drive means (36/.) operable rotatably to drive the filter element (29) and blanking off means (38) mounted within the filter element (29) for blanking off the perforations thereof over a predetermined region. The filtering arrangement further also comprises rotatable brush means (48) provided in cleaning engagement with a section of the filter element (29) for releasing foreign matter restrained thereby. The brush means (48) are positioned adjacent the blanking off means (38) at the inner side of the filter element (29) and are movable from an inoperative position out of engagement with the filter element (29) to an operative position engaging said filter element (29). Control means (56, 84) are provided for intermittently moving the brush means (48) in and out of engagement with the filter element (29). <IMAGE></p> |
