The present invention features that the suction fan possesses of an outer housing with trunnion and there are air-inlet and air-outlet at two ends of axial housing, their peripheric surface is spherical in shape. By manual or motor-driven mechanism, the housing can be turned 180 degree, it can suck dust or back blown eject dust. For carrying out wet method of dust removing by bubbling and washing, the back blown air contained with dust is exhausted along dust sucking pipe and bubbling pipe which is inserted in the water and equiped with check valve. The other components of said dust catcher are same as that of ordinary one. The ordinary dust catcher can also be refitted into said type by said method. |