Particulate bed dust collectors

Claim 1

In a dust collecting system, in combination, a plenum chamber, a dirty gas inlet at one end of said plenum chamber, a solids removal means at the bottom of the plenum chamber, a plurality of filter modules each comprising a container having an upper and a lower chamber, a perforated plate in each module separating the upper and lower chamber, a bed of particulate filter material supported on each perforated plate, separate conduits one for each module connecting its upper chamber to said plenum chamber, a clean gas duct, a backflush gas duct, valve means individual to each module adapted to selectively connect the lower chamber of each module to the clean gas duct and the backflush gas duct, means maintaining the pressure in the clean gas duct less than the pressure in the plenum chamber, means maintaining the pressure in the backflush duct greater than the pressure in the plenum chamber, and a recirculating system comprising a cyclone collector and a fan connected in series between an end of the plenum chamber remote from said dirty gas inlet and the inlet end of the chamber, whereby agglomerated dust backflushed from a filter bed into the plenum chamber and failing to settle to the solids removal means is carried by the recirculating system and separated in the cyclone thereof.