A conventional dust-catcher for blast furnace gas comprises a pressure vessel, with a gas inlet and outlet dome (14), a separation chamber (16) and a lower dust hopper (18), and a diffuser pipe (26) extending axially through the gas inlet and outlet dome (14) into the separation chamber (16). To increase the separation efficiency of such a dust hopper (18), it is proposed to centrally arrange a flow deflecting chamber (50, 50′), having a smaller cross-section than the separation chamber (16), in the separation chamber (16), so that there remains an annular settlement chamber (52) between the inner wall of the separation chamber (16). The diffuser pipe (26) is connected to this flow deflecting chamber (50, 50′) so as to axially discharge a downward gas flow into the top end of the flow deflecting chamber (50, 50′), wherein this downward gas flow is deflected upward. An annular swirling device (58) with guide vanes (60) is arranged in the top end of the flow deflecting chamber (50, 50′) around the lower end of the diffuser pipe (26) and acts as outlet opening for the gas flow into the into the pressure vessel of the dust-catcher. The guide vanes (60) form a vortex gas flow rising around the diffuser pipe (26) upward into the gas inlet and outlet dome (14).