Patent ID: 8052771

Claim:
A removable dust collecting device ( 100 ) for an air conduit consists essentially of: a dust collecting tubes set ( 1 ); the set ( 1 ) is provided about an inner wall of an air conduit ( 51 ); said set ( 1 ) includes a plurality of hollow dust collecting tubes ( 2 a - 2 f ) made of soft material and having different diameters; said dust collecting tubes ( 2 a - 2 f ) are arranged in a concentric fashion by covering the one having small diameter with another one having larger diameter; the tubes ( 2 a - 2 f ), after collecting dust fully, are removed from the air conduit ( 51 ) sequentially from an innermost tube; an adhesive layer ( 3 ) is applied on each inner surface ( 21 a - 21 f ) of said dust collecting tubes ( 2 a - 2 f ) and on an outer surface ( 22 f ) of the outmost dust collecting tube ( 2 f ) for attaching each other and collecting dust; and an intake ( 24 a - 24 f ) is provided respectively at an end of said dust collecting tubes ( 2 a - 2 f ) where is about an air conditioning unit ( 5 ); an outlet ( 25 a - 25 f ) is provided respectively at an end of said dust collecting tubes ( 2 a - 2 f ) where connected to an air conditioning tube ( 51 ), and a pull string ( 4 a - 4 f ) is provided longitudinally on said dust collecting tubes ( 2 a - 2 f ) and extended from two extreme ends hereof for removing the tubes ( 2 a - 2 f ).