Foreign matter removal device

A foreign matter removal device which removes foreign matter contained in a fluid in a pipe by using a swirling flow in a trap having a cylindrical shape, the foreign matter removal device comprising:

• an inlet for causing the fluid to flow into the trap;
• a tubular structure provided at a bottom part of the trap so as to separate the fluid having flowed in through the inlet into an inner fluid having the swirling flow flowing inside the tubular structure and an outer fluid having the swirling flow flowing outside the tubular structure;
• a gap between an inner wall of the trap and the tubular structure, which captures higher specific gravity foreign matter than that of the fluid and settled by gravity;
• an outlet for causing the inner fluid from which the higher specific gravity foreign matter has been separated by the tubular structure to flow out of the trap;
• an opened space located vertically above the outlet, is located opposite the outlet in a center of the trap above the inlet, and the opened space to remove small specific gravity foreign matter;
• another outlet connected to the opened space to discharge the small specific gravity foreign matter;
• a plate shaped so as to divide an opening of the opened space in the vertical direction, so that the small specific gravity foreign matter having flowed into the opened space is promoted floating up toward the other outlet;
• and
• a gas-liquid separator which is provided at a center part of the trap and below the inlet, has a horizontal cross section whose area is smaller than that of the outlet, and inhibits the swirling flow from flowing toward the outlet.