Air filter systems, filter bag assemblies, filter bags and methods

An air filter system comprising:

• a tubesheet separating a housing into a dirty air chamber and a clean air chamber, wherein the tubesheet comprises an aperture placing the dirty air chamber in fluid communication with the clean air chamber, and wherein the housing comprises an access panel located across the dirty air chamber from the tubesheet;
• a filter bag assembly located in the dirty air chamber, the filter bag assembly comprising:
• a flange assembly comprising a clean air outlet extending through the flange assembly, the clean air outlet in fluid communication with the aperture in the tubesheet;
• a cage comprising a first cage end attached to the flange assembly and extending over a cage length to a second cage end distal from the flange assembly, the cage defining a cage axis extending between the first cage end and the second cage end, the cage further comprising a plurality of struts extending away from the interior face of the flange assembly towards the second cage end;
• and
• a filter bag comprising filter media defining an interior volume of the filter bag, wherein the filter bag extends from a first end to a second end, wherein a portion of the filter media defines a bag opening at the first end of the filter bag, and wherein the second end of the filter bag comprises a closed second end distal from the bag opening;
• wherein the bag opening is attached to the flange assembly, wherein the bag opening and the flange assembly form a seal around the clean air outlet such that air entering the interior volume of the filter bag must pass through the filter media of the filter bag or through the clean air outlet of the flange assembly;
• a filter access port in the access panel of the housing, the filter access port comprising a cover movable between a closed position and an open position, wherein the cover closes the filter access port when the cover is in the closed position and wherein the filter bag assembly can be inserted into or removed from the dirty air chamber through the filter access port when the cover is in the open position;
• a filter guide in the dirty air chamber, the filter guide extending along a guide axis passing through the tubesheet and the access panel, wherein the guide axis is aligned with a bag axis, and wherein the filter bag assembly is mounted on the filter guide, wherein the filter guide is located within the interior volume of the filter bag when the filter bag assembly is mounted on the filter guide;
• a seal located around the aperture in the tubesheet such that air passing through the aperture in the tubesheet must pass through the clean air outlet in the flange assembly before entering or leaving the interior volume of the filter bag;
• wherein the cover is configured to apply a seal force on the second cage end through the second end of the filter bag, wherein the seal force is directed along the cage axis and is transferred to the seal through the cage and the flange assembly;
• and
• a pulse generator located in the clean air chamber and configured to deliver pulses of air into the interior volume of the filter bag through the aperture in the tubesheet and the clean air outlet of the flange assembly, the pulses of air passing through the aperture and the clean air outlet before reaching the interior volume of the filter bag.