Patent ID: 7921790

Claim:
A ballast water exchanger for a ship with a ballast tank, comprising: a partition provided in the ballast tank with an upper portion of the partition being open, and an inflow port and an outflow port which are open through a bottom of the ship; wherein the partition forms a weir extending in a widthwise direction of a hull in the ballast tank, and divides a region in the ballast tank into an inflow area located in front in a headway direction of the hull and an outflow area located in rear in the headway direction of the hull; wherein a height of the partition is at least 0.2 times an overall height of the ballast tank; and wherein the inflow port is disposed in the inflow area, and the outflow port is disposed in the outflow area, and the inflow area and the outflow area are spaced apart from each other in the headway direction of the hull so that forward motion of the hull causes seawater outside the ship to flow into the ballast tank through the inflow port and the seawater in the ballast tank to flow out of the ship through the outflow port to create circulation flow of the seawater in the ballast tank.