Ballast tank drainage structure

Abstract

To provide a drainage structure of a ballast tank in which the drainage time of residual ballast water is not significantly lengthened even if the number of communication holes and their opening areas are reduced.SOLUTION: The total opening area of multiple vertical frame members 17, multiple girder members 11, and multiple communication holes 25 provided in each part of multiple floor members 13 facing each small partition chamber 19 included in 3 or 4 rows of small partition chambers 20Wa-20Wd in the ship width direction, decreases away from the small partition chamber provided with a suction port 21 centered thereon in multiple small partition chambers in a prescribed region centered on the small partition chamber provided with the suction port. The communication hole 25L is not provided in each part of the girder members and the vertical frame members facing a part or all of the small partition chambers among the multiple small partition chambers in the small partition chamber rows in the ship width direction, which are a part or all of the small partition chamber rows 20Wf-20Wh in the ship width direction except for the small partition chamber rows 20Wa-20Wd in the ship width direction.SELECTED DRAWING: Figure 2

Claims

1. A plate frame structure is formed in a ballast tank located between the bottom plate and the inner bottom plate of a ship, wherein a plurality of girder members are provided on the bottom plate, extending in the longitudinal direction of the hull and spaced apart in the width direction perpendicular to the longitudinal direction, and a plurality of floor members are provided on the bottom plate, intersecting with the plurality of girder members and extending within the ballast tank in the width direction and spaced apart in the longitudinal direction, so as to form a grid-like plurality of large compartments between the bottom plate and the inner bottom plate, and a plurality of longitudinal frame members are provided on the bottom plate within the plurality of large compartments, extending in the longitudinal direction and spaced apart in the width direction, and a plurality of small compartments are formed in the bottom-side region of each of the plurality of large compartments, partitioned in the width direction by the plurality of longitudinal frame members, At least one intake port is provided for at least one of the smaller compartments within one of the larger compartments, The plurality of girder materials and the plurality of floor materials are provided with a plurality of water flow holes for circulating ballast water between the plurality of large compartments, A drainage structure for a ballast tank, comprising a plurality of water passages provided in the plurality of girder members, the plurality of floor members, or the plurality of vertical frame members, which guide residual ballast water remaining in the plurality of small compartments within the plurality of large compartments to at least one of the small compartments, each of which is provided with at least one suction port, for draining ballast water from the ballast tank, The aforementioned plate frame structure is configured such that a plurality of rows of small compartments in the width direction are arranged in series in the width direction of the ship, and a plurality of these rows are arranged in the length direction of the ship. The plurality of water passages provided in the plurality of small compartments included in the plurality of rows of small compartments in the width direction, which are arranged on the stern side in the length direction, including the row of small compartments in the width direction that includes the small compartment in which at least one suction port is provided, are provided so that residual ballast water flows into the small compartment in which at least one suction port is provided. The plurality of water passages provided for a plurality of compartments included in a plurality of rows of compartments in the width direction of the ship are arranged such that the total opening area of ​​the plurality of water passages provided for a compartment with at least one intake port is the maximum total opening area, and the total opening area decreases as you move away from the compartment with at least one intake port. A drainage structure for a ballast tank, characterized in that, of the plurality of rows of small compartments in the width direction, one or more water passages provided for a plurality of small compartments included in a plurality of rows of small compartments in the width direction that are located towards the bow in the longitudinal direction of the ship, rather than the row of small compartments in the width direction that includes the small compartment having at least one suction port, are not provided in any of the girder members and longitudinal frame members facing the plurality of small compartments.

2. A plate frame structure is formed in a ballast tank located between the bottom plate and the inner bottom plate of a ship, wherein a plurality of girder members are provided on the bottom plate, extending in the longitudinal direction of the hull and spaced apart in the width direction perpendicular to the longitudinal direction, and a plurality of floor members are provided on the bottom plate, intersecting with the plurality of girder members and extending within the ballast tank in the width direction and spaced apart in the longitudinal direction, so as to form a grid-like plurality of large compartments between the bottom plate and the inner bottom plate, and a plurality of longitudinal frame members are provided on the bottom plate within the plurality of large compartments, extending in the longitudinal direction and spaced apart in the width direction, and a plurality of small compartments are formed in the bottom-side region of each of the plurality of large compartments, partitioned in the width direction by the plurality of longitudinal frame members, At least one intake port is provided for at least one of the smaller compartments within one of the larger compartments, The plurality of girder materials and the plurality of floor materials are provided with a plurality of water flow holes for circulating ballast water between the plurality of large compartments, A drainage structure for a ballast tank, comprising a plurality of water passages provided in the plurality of girder members, the plurality of floor members, or the plurality of vertical frame members, which guide residual ballast water remaining in the plurality of small compartments within the plurality of large compartments to at least one of the small compartments, each of which is provided with at least one suction port, for draining ballast water from the ballast tank, The aforementioned plate frame structure is configured such that a plurality of rows of small compartments in the width direction are arranged in series in the width direction of the ship, and a plurality of these rows are arranged in the length direction of the ship. The plurality of water passages provided in the plurality of rows of small compartments in the width direction, including the row of small compartments in the width direction that includes the small compartment in which at least one intake port is provided, which is arranged on the stern side in the longitudinal direction of the ship, and in the plurality of small compartments included in one row of small compartments in the width direction that is arranged on the bow side relative to the plurality of rows of small compartments in the width direction, are provided so that residual ballast water flows into the small compartment in which at least one intake port is provided. The plurality of water passages provided for a plurality of compartments included in a plurality of rows of compartments in the width direction of the ship are arranged such that the total opening area of ​​the plurality of water passages provided for a compartment with at least one intake port is the maximum total opening area, and the total opening area decreases as you move away from the compartment with at least one intake port. A drainage structure for a ballast tank, characterized in that, of the plurality of rows of small compartments in the width direction, one or more water passages provided for a plurality of small compartments included in a plurality of rows of small compartments in the width direction that are located further forward in the longitudinal direction than one row of small compartments in the width direction that are located further forward in the longitudinal direction than one row of small compartments in the width direction that are located further forward in the longitudinal direction of the ship, are not provided in any of the girder members and longitudinal frame members that face the plurality of small compartments.

3. A drainage structure for a ballast tank according to claim 1 or 2, wherein there are two or more rows of small compartments in the width direction, each row of small compartments in the width direction, which are arranged on the stern side in the length direction, and each row of small compartments in the width direction includes the small compartments in the width direction, each of which includes the small compartments in which at least one suction port is provided.

4. The drainage structure for a ballast tank according to claim 1 or 2, wherein the total opening area of ​​each of the plurality of water passages provided for each of the plurality of small compartments included in the row of small compartments in the ship width direction, which includes the small compartment having at least one suction port, decreases in stages as it moves away from the small compartment having at least one suction port.

5. The drainage structure for a ballast tank according to claim 3, wherein the total opening area of ​​each of the plurality of water passages provided for a plurality of small compartments included in the row of small compartments in the width direction, which includes the small compartment having at least one suction port, and the row of small compartments in the width direction, which is arranged on the stern side in the length direction, is progressively smaller than the total opening area of ​​each of the plurality of water passages provided for a plurality of small compartments included in the plurality of small compartments in the row of small compartments in the width direction, which includes the small compartment having at least one suction port.

6. The drainage structure for a ballast tank according to claim 4, wherein the total opening area of ​​each of the plurality of water passages provided for a plurality of small compartments included in the row of small compartments in the width direction, which includes the small compartment having at least one suction port, and the row of small compartments in the width direction, which is arranged on the stern side in the length direction, is progressively smaller than the total opening area of ​​each of the plurality of water passages provided for a plurality of small compartments included in the plurality of small compartments in the row of small compartments in the width direction, which includes the small compartment having at least one suction port.

7. The drainage structure for a ballast tank according to claim 1, wherein the total opening area of ​​the water passages provided in the floor material facing the plurality of compartments included in the row of compartments in the width direction of the ship is such that the total opening area of ​​the water passages provided in the floor material facing a reference compartment in the row of compartments in the length direction of the ship, which includes the compartment in which at least one suction port is provided, is the maximum total opening area, and the area away from the reference compartment is less than the maximum total opening area.

8. The drainage structure for a ballast tank according to claim 1 or 2, wherein the suction port is provided in each of two or more adjacent compartments among the plurality of compartments included in one row of compartments in the width direction of the ship.

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