A filter including a filter wall extending between first and second opposed ends, the filter wall being tubular and surrounding a filter cavity, the filter wall including filtration material permeable to air so that the filter cavity is in fluid communication with an environment of the filter through the filter wall, a filter inlet defined in the first end and in fluid communication with the filter cavity, and a tray extending within the filter cavity and freely rotatable within the filter cavity about an axis of rotation extending longitudinally within the filter cavity, the tray having a center of gravity offset from the axis of rotation, the tray being radially inwardly spaced from the filter wall, the tray being radially outwardly spaced from the filter inlet. A filter module including such a filter and a method of protecting a horizontally extending tubular filter wall from debris are also discussed.