A foreign matter removal device removes foreign matter contained in a fluid. The fluid is caused to flow into the trap portion and is separated into an inner fluid flowing inside a separation portion and an outer fluid flowing outside the separation portion. First foreign matter contained in the outer fluid and having a higher specific gravity than the fluid is captured in a gap between an inner wall of the trap portion and the separation portion. Separation of second foreign matter contained in the inner fluid and having a lower specific gravity than the fluid is promoted by a gas-liquid separation portion, and the second foreign matter is discharged to outside, through a foreign-matter-discharging-means-connection portion provided in a ceiling on the vertically upper side at a center part of the trap portion, from foreign-matter-discharging means.

A hydrogen-water separator for a fuel cell includes an upper separation chamber having a first cylindrical sidewall defining an inlet port and a lower collection chamber configured to collect separated water. The collection chamber has a bottom and a second cylindrical sidewall defining a drain port disposed above the bottom. A divider is disposed between the separation chamber and the collection chamber. The divider spans the first cylindrical sidewall and defining one or more openings. An outlet tube is arranged vertically in the separation chamber and having an entrance that is disposed above the divider and below the inlet port.

The invention describes a vortex finder for a cyclonic separator. The vortex finder includes a plurality of stationary vanes around which incoming air is guided into the vortex finder, in which a side of the vanes facing the incoming air is provided with a protrusion at a stagnation point. The protrusion is shaped so as to guide the incoming air into the vortex finder, and have a concave side following a shape of a neighboring vane, and a rounded top. Further, the protrusion has a height in a range between 70% and 130%, and in a range between 85% and 115% of a gap width between the vanes. The gap width between adjacent vanes increases from an outside to an inside of the vortex finder. A vacuum cleaner that includes a cyclonic separator has such a vortex finder.

A vortex finder, for a cyclonic separator, includes a plurality of stationary vanes having a round convex front end around which incoming air is guided into the vortex finder, wherein, where air separates from the plurality of stationary vanes inside of the vortex finder, a cross-section of the plurality of stationary vanes has only one sharp edge. Preferably, a mean line of the cross-section of the plurality of stationary vanes does not cross a chord line in an upstream half of the cross-section. Preferably, a side of the plurality of stationary vanes facing the incoming air is provided with a protrusion at a stagnation point. The protrusion may be shaped so as to guide the incoming air into the vortex finder, and may have a concave side following a shape of a neighboring vane, and a rounded top.

A foreign matter removal device removes foreign matter contained in a fluid. The fluid is caused to flow into the trap portion and is separated into an inner fluid flowing inside a separation portion and an outer fluid flowing outside the separation portion. First foreign matter contained in the outer fluid and having a higher specific gravity than the fluid is captured in a gap between an inner wall of the trap portion and the separation portion. Separation of second foreign matter contained in the inner fluid and having a lower specific gravity than the fluid is promoted by a gas-liquid separation portion, and the second foreign matter is discharged to outside, through a foreign-matter-discharging-means-connection portion provided in a ceiling on the vertically upper side at a center part of the trap portion, from foreign-matter-discharging means.