Abstract: A ventilating suction and exhaust fan device of Plate type comprising a casing of cylindrical shape, a partition plate mounted within the casing and extending in a horizontal plane passing through a central axis of the casing and having a rectangular opening formed therein, a cylindrical impeller of Plate type rotatably mounted in said opening of the partition plate coaxially with respect to the casing, said impeller comprising at least one impeller section for exhaustion, at least one impeller section for suction and a central vertical partition disc disposed between said impeller sections, first hood means for preventing the impeller section for exhaustion from contacting the suction air, second hood means for preventing the impeller section for suction from contacting the exhaust air, and guide means for converting centrifugal flows generated by said impeller sections to axial flows.

Abstract: A ventilating suction and exhaust fan device of Sirocco type comprising a casing of cylindrical shape, a partition plate mounted within the casing and extending in a horizontal plane passing through a central axis of the casing and having a rectangular opening formed therein, a cylindrical impeller of Sirocco type rotatably mounted in said opening of the partition plate coaxially with respect to the casing, said impeller comprising a central vertical partition disc, a first cylindrical impeller section for exhaustion of air arranged on one side of the disc and a second cylindrical impeller section for suction of air arranged on the other side of the disc, first hood means for preventing the first impeller section from contacting the suction air, second hood means for preventing the second impeller section from contacting the exhaust air, and guide means for converting centrifugal flows generated by the impeller sections to axial flows.