JPH05116676A - Silt preventing method in ballast tank - Google Patents

Abstract

PURPOSE:To prevent silt at the bottom of a ballast tank by jetting water jet from the jet nozzle of a water jet header so as to wash away mud deposited at the bottom part of the ballast tank, and discharging this mud together with the ballast water from a suction pipe. CONSTITUTION:Ballast water is sucked by a pump 10 through a suction pipe 11 and discharged from a discharge hole 13 though a discharge pipe 9 and a valve 12. In this case, a jet pipe 14 is branched from the discharge pipe 9. When water jet is jetted from the jet pipe 14 to wash away mud deposited at the bottom part of a ballast tank, the valve 12 is closed and a valve 15 provided at the jet pipe 14 is opened, and then the ballast water is sucked by the pump 10 through the suction pipe 11. Then the ballast water flows into the jet pipe 14 from the valve 15 and is jetted from the jet nozzle 17 of a water jet header 16. The silt at the bottom of the ballast tank is thereby prevented so as to lower deposition weight and dissolve the generation of rust.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing silt in a ballast tank, which prevents mud in the ballast water injected into the ballast tank from being silted over the entire area of the ballast tank.

[0002]

2. Description of the Related Art Recently, large-sized ships have deep water for deep-draining. Therefore, there is a seawater inlet for ballast water to be injected into a ballast tank at the bottom of the ship. It tends to be injected into ballast tanks. Then, the injected mud in the seawater is siltated at the bottom of the ballast tank and cannot be pumped out by the pump for discharging the ballast water. Especially when the bottom area of the ballast tank increases like the double hull tanker,
It becomes a big problem.

In order to remove such foreign matter in seawater, a strainer has conventionally been arranged in the middle of the suction pipe. Although such a strainer can prevent large dust from entering, the ballast as described above is used. The entry of mud in the water could not be prevented and the mud was still settling at the bottom of the ballast tank.

[0004]

When mud silts on the bottom of the ballast tank, the loadable weight of the ship is reduced by that much, and rust easily occurs in the ballast tank.

The present invention has been made in order to solve the above-mentioned problems of the prior art, and provides a method for preventing siltation of a ballast tank, which prevents mud from settling at the bottom of the ballast tank. The purpose is to do.

[0006]

A method for preventing the siltation of a ballast tank according to the present invention is for discharging ballast water to the rear end of the ship in the front-rear direction in the area surrounded by partition walls on all four sides of the ballast tank. In addition to the suction pipe of the above, a water jet header having a plurality of water jet nozzles is provided at the front end, and water jetted from a plurality of water jet nozzles toward the rear of the ship allows the mud accumulated on the bottom of the ballast tank to be discharged. And the mud is discharged from the suction pipe to the outside of the ballast tank together with the ballast water.

[0007]

According to the method of preventing siltation of a ballast tank according to the present invention, a suction pipe for discharging ballast water is provided at the rear end of the ship in the front-rear direction in a region surrounded by partition walls on all sides of the ballast tank. , The front end is provided with a water jet header having a plurality of water jet nozzles, and the water jets are jetted from the plurality of water jet nozzles toward the rear of the ship to wash away the mud accumulated on the bottom of the ballast tank, and the suction The mud is discharged from the pipe together with the ballast water to the outside of the ballast tank. Then, by appropriately selecting the pitch at which the water is sprayed, it does not deposit mud to the extent that it becomes difficult to wash it off with water, so no special consideration is given to the means for discharging mud, and the existing It can be discharged with a ballast water discharge device. For this reason, it is possible to prevent siltation of the ballast tank at a cost as low as that of the water jet piping.

[0008]

EXAMPLE A method for preventing siltation of a ballast tank according to an example of the present invention will be described with reference to FIGS. FIG. 1 is an explanatory view showing a piping system for carrying out a silt prevention method for a ballast tank according to an embodiment of the present invention. Reference numerals 1, 2, 3 in the figure
Is a partition wall in the ballast tank along the longitudinal direction of the ship, reference numeral 4 is a partition wall in the ship width direction between the ballast tank and the pump chamber 5, and reference numerals 6, 7 and 8 are ship width directions in the ballast tank. It is a partition wall. The area surrounded by the partition wall is one unit for carrying out the method for preventing siltation of a ballast tank according to one embodiment of the present invention, and such an area is 6 sections in FIG.

The dotted line shows the existing ballast water discharge pipe 9, and the ballast water is sucked by the pump 10 by the suction pipe 11.
Is discharged from the discharge port 13 through the ballast water discharge pipe 9 and the open valve 12.

The chain line with black circles is a jet water pipe 14 branched from the ballast water discharge pipe 9 in order to carry out the method for preventing siltation of a ballast tank according to one embodiment of the present invention. When the jet water is jetted to wash away the mud accumulated on the bottom of the ballast tank, the valve 12 is closed and the valve 15 provided in the jet water pipe 14 is opened (closed when the ballast water is discharged), and suctioned by the pump 10. Aspirate ballast water from tube 11. In this way, the ballast water enters the jet water pipe 14 through the valve 15 and reaches the jet water header 16. Then, the ballast water is jetted in the rearward direction of the ship from the plurality of jet nozzles 17 provided in the jet water header 16.

FIG. 2 is an explanatory view showing the flow of jet water and mud in one region surrounded by a partition wall. At the bottom of the ballast tank, for example, a height of 8
A plurality of 00 mm stringers 18 are attached at intervals of about 800 mm along the longitudinal direction of the ship. At least one jet nozzle 17 of the jet water header 16 is arranged in the groove portion 19 formed by the adjoining longitudinal members 18, and the jet water is installed in the suction pipe 11 along the groove portion 19. The mud that has accumulated at the bottom of the ballast tank flows toward the person who is present. A plurality of openings are provided at a constant pitch in the height of the stringer 18 close to the bottom of the ballast tank, and the jetted water that has washed away the mud flows from the groove 19 through this opening by the suction pipe 11. Other groove 19 near
And finally reaches the suction pipe 11 and is discharged through the ballast water discharge pipe 9.

In the method for preventing siltation of a ballast tank according to one embodiment of the present invention, since the stringer 18 can be used as a so-called straightening plate as described above, it is necessary to discharge the ballast water as described above. A pump having a discharge pressure of about ² to 3 kgf / cm ² can be used to sufficiently achieve the purpose.

[0013]

As described above, according to the present invention, mud does not settle in the ballast tank, and it is possible to prevent a decrease in load weight and generation of rust.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a piping system for carrying out a silt prevention method for a ballast tank according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing flows of jet water and mud in one region surrounded by a partition wall.

[Explanation of symbols]

 1 Partition wall inside the ballast tank along the longitudinal direction of the ship 2 Partition wall inside the ballast tank along the longitudinal direction of the ship 3 Partition wall inside the ballast tank along the longitudinal direction of the ship 4 Between the ballast tank and the general cargo hold Partition wall between, reference numeral 5 Pump room 6 Partition wall in the ballast tank in the ship width direction 7 Partition wall in the ballast tank in the ship width direction 8 Partition wall in the ballast tank in the ship width direction 9 Ballast water discharge pipe 10 Pump 11 Suction pipe 12 Valve 13 Discharge port 14 Water jet piping 15 Valve 16 Water jet header 17 Water jet nozzle 18 Longitudinal member 19 Groove

Claims (1)

[Claims] 1. A spray pipe for discharging ballast water is provided at the rear end of the ship in the front-rear direction in a region surrounded by partition walls on all four sides of the ballast tank, and the front end has a plurality of injection nozzles. By installing a water header and injecting water jets from multiple jet nozzles toward the rear of the ship, the mud accumulated on the bottom of the ballast tank is washed away, and the mud is discharged from the suction pipe together with the ballast water to the outside of the ballast tank. A method to prevent siltation of ballast tanks, characterized by discharging.