Tank arrangement adapted for a submersible pump

A ballast system for a marine structure, comprising:

• a ballast tank in fluid communication with a tank arrangement via a first inlet conduit,
• wherein said tank arrangement comprises:
• a closed storage space defined by at least one tank wall;
• at least one fluid inlet in fluid communication with said first inlet conduit that introduces a bilge fluid, a ballast fluid, or both into said storage space;
• and
• at least one fluid outlet that removes at least a portion of said bilge fluid, said ballast fluid, or both from said storage space;
• wherein said at least one fluid outlet is at least partially formed by a caisson containing at least a portion of a submersible pump,
• wherein said submersible pump comprises a pump outlet and a pump inlet,
• wherein said caisson comprises a space between said submersible pump and an inner surface of said caisson that receives fluid from said pump outlet, and
• wherein said caisson further comprises at least one circulation conduit having an inlet and an outlet that circulates at least a portion of said bilge fluid, said ballast fluid, or both from said pump outlet to said pump inlet;
• a priming ejector that removes air from said storage space,
• wherein said priming ejector is in fluid communication with an air discharge conduit comprising a plurality of apertures arranged along a length thereof,
• wherein said air discharge conduit discharges said air outside of said storage space, and
• wherein said priming ejector is coupled to said caisson and said at least one circulation conduit at a location outside of said storage space;
• and
• a priming circulation conduit having a first end coupled to said priming ejector and a second end coupled to an ejector outlet for ejecting at least air, said ejector outlet of said priming ejector is arranged inside of said storage space and proximate said submersible pump to enable said submersible pump to remove said air.