U.S. patent application number 15/771967 was filed with the patent office on 2018-08-16 for apparatus for automatically managing ballast water of ship, and operation method thereof.
The applicant listed for this patent is DESEN CO., LTD., ETS CO., LTD.. Invention is credited to Yong-Kyung KIM.
Application Number | 20180229821 15/771967 |
Document ID | / |
Family ID | 58662222 |
Filed Date | 2018-08-16 |
United States Patent
Application |
20180229821 |
Kind Code |
A1 |
KIM; Yong-Kyung |
August 16, 2018 |
APPARATUS FOR AUTOMATICALLY MANAGING BALLAST WATER OF SHIP, AND
OPERATION METHOD THEREOF
Abstract
The present invention relates to an apparatus for automatically
managing the ballast water of a dual-hulled ship and, more
specifically, to an apparatus for automatically managing the
ballast water of a ship, the apparatus dividing the structure of an
integrated ballast water tank into ballast water tanks of a
multi-layered structure, and filling each ballast water tank with
seawater, so as to perform the original function thereof of
maintaining the water-line by means of the ballast water, and
having a structure and a device so as to utilize the seawater, used
as cooling water, residential water, water for miscellaneous use,
and the like, as the seawater of the ballast water tanks, thereby
integrally managing the usage of the seawater of the ship, and
continuously and successively changing the seawater of the ballast
water tanks while the ship is sailing.
Inventors: |
KIM; Yong-Kyung;
(Jeollabuk-do, KR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ETS CO., LTD.
DESEN CO., LTD. |
Jeollabuk-do
Jeollabuk-do |
|
KR
KR |
|
|
Family ID: |
58662222 |
Appl. No.: |
15/771967 |
Filed: |
November 4, 2016 |
PCT Filed: |
November 4, 2016 |
PCT NO: |
PCT/KR2016/012625 |
371 Date: |
April 27, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B63B 43/06 20130101;
B63B 13/00 20130101; B63H 21/383 20130101; B63J 1/00 20130101 |
International
Class: |
B63B 43/06 20060101
B63B043/06; B63H 21/38 20060101 B63H021/38; B63J 1/00 20060101
B63J001/00; B63B 13/00 20060101 B63B013/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 5, 2015 |
KR |
10-2015-0155052 |
Claims
1. An apparatus for automatically managing the ballast water of a
dual-hulled ship to integrally manage seawater used in the ship,
comprising: ballast water tanks of a multi-layered structure; water
level sensors for the ballast water tanks; bypass valves supplying
seawater to adjacent ballast tanks; piping connecting a bottom
ballast tank a desalination unit for cooling water and residential
water etc., and to a pipe for supplying technical water such as
cooling water for mechanical units; and a control unit, which is an
electronic controller, controlling to open the bypass valves so
that the seawater may be supplied to adjacent ballast tanks, when
the bottom ballast tank becomes empty.
2. The apparatus of claim 1, wherein the ballast water tanks of a
multi-layered structure are constructed by modification of void
tanks to ballast water tanks so that the ballast water tanks can
contain more water than the conventional ballast water and
installing additional water level sensors and bypass valves on each
of the modified ballast water tanks.
3. The apparatus of claim 1, wherein the control unit, which is an
electronic controller, controls valves to inflow seawater, controls
valves to supply seawater to the ballast water tanks, and controls
the bypass valves to supply seawater to the desalination device,
the technical water supply pipe, and the residential water supply
pipe from the bottom ballast tank during sailing for cargo
shipments; and when seawater must be discharged out of ship due to
the cargo shipping, controls seawater discharge valves.
Description
TECHNICAL FIELD
[0001] The present invention relates to an apparatus for
automatically managing the ballast water of a dual-hulled ship and,
more specifically, to an apparatus for automatically managing the
ballast water of a ship, the apparatus dividing the structure of an
integrated ballast water tank into ballast water tanks of a
multi-layered structure, and filling each ballast water tank with
seawater, so as to perform the original function thereof of
maintaining the water-line by means of the ballast water, and
having a structure and a device so as to utilize the seawater, used
as cooling water, residential water, water for miscellaneous use,
and the like, as the seawater of the ballast water tanks, thereby
integrally managing the usage of the seawater of the ship, and
continuously and successively changing the seawater of the ballast
water tanks while the ship is sailing.
RELATED ART
[0002] Since 1993, the shipbuilding industry has been booming in
Korea as a requirement for the double hull of the new ship. Since
2005, ships without double hulls have been forcibly removed, but
single hull oil tankers still operate in Korea. Because of this,
there is a risk of oil spillage from the ship and the insurance
premium of the ship is high. In this regard, the market for ballast
water management systems also presents new opportunities.
[0003] The ballast water management system of the ship is regulated
by BWM (ballast water management) Convention under the United
Nations' International Maritime Organization (IMO). Korea is also
stipulating the Marine Pollution Prevention Act since 2009. The
Convention, which is ratified by nations equaling 35% of the
world's fleet, is effective 12 months later and has been ratified
by 44 nations, 32.86% as of Jan. 30, 2015. In other words, it will
be possible that the effective date of the Convention within at
least one year. Korea has a legal basis for the Ballast Water
Management Act (Ministry of Maritime Affairs and Fisheries Notice
No. 2015-37, Apr. 1, 2015) (ballast water line and load
line--excerpt from Korean Rules for Classification of Steel Wire,
see FIG. 8).
[0004] A ship such as a cargo ship cannot be navigated because the
center of gravity of the ship is so high that the propeller is not
submerged under water when the cargo is not loaded, and there is a
high risk that it can be easily overturned by sea waves. Therefore,
by lowering the center of gravity of the ship so that the propeller
can be submerged under water, it can sail and remain stable. In
order to perform this function, the seawater is stored in the ship
hull, which is called a ballast water, and an empty space for
storing the seawater should be provided. The point at which the
ship is fully loaded with cargo is called the design load water
line (DLWL) and the point where the propeller is barely submerged
under water is called the ballast water line (BWL).
[0005] FIG. 9 shows a correlation table between the Deadweight
tonnage (Dwt) and an amount of the ballast water of a general ship
(Korean Register of Shipping data) and shows the ballast water load
of the cargo ships. According to this, the ship should load
seawater up to 50 wt % amount of cargo, and the amount of fuel used
to load and discharge ballast water occupy about 3 to 5% of the
fuel consumption of the ship (according to the data from US Coast
Guard). This cost is similar to the net profits of all the shipping
companies in Korea, according to the Korea Ship Owners
`Association` s annual report published in 2004.
[0006] In general, the structure of the ballast water tank used for
the double hull cargo ship is shown in FIG. 10. FIG. 10 is a
cross-sectional view of the ballast water tank, showing a bottom
tank, a hopper side tank, a side tank, and a topside tank.
[0007] The devices for supplying ballast water in the ship are
specified in detail in FIG. 11 in accordance with the legal
regulations. FIG. 11 shows classification rules relating to general
ballast equipment.
[0008] FIG. 12 is a schematic diagram of a typical ballast tank
arrangement.
[0009] Commonly used ballast water management methods are
classified into three types.
[0010] The isolation method is used when the ballast water is so
polluted that it is difficult or impossible to purify.
[0011] The treatment method is a method in which the ballast water
containing living organisms is subjected to various processes such
as electrolysis, ultraviolet ray treatment, chemical treatment,
plasma treatment, and the like, for killing the living organisms,
after which the ballast water is filtered.
[0012] The exchange method is mainly used when the contamination of
the ship ballast water is not severe or the amount of the water for
treatment is small.
[0013] FIG. 13 shows the ship ballast water management method
recommended by the United Nations Marine Environment Protection
Committee (MEPC) under the International Maritime Organization
(IMO).
[0014] According to the currently used ballast water management
system BWMS, the ship generally sails to the destination port with
sea water loaded in the ballast water tank and discharges the
ballast water for cargo loading. In this process, A large amount of
active substance is generated, including transport-prohibited
living organisms.
[0015] FIG. 14 shows the transport-prohibited life species
(extracted from KBS 1TV on Nov. 24, 2004).
[0016] The ballast water contains pollutants generated due to the
various methods used to kill the 10 transport-prohibited living
organisms regulated by UN. The ballast water, the bilge water, the
toilet water, the cleaning water, etc. containing contaminants are
collectively referred to as the active substance. The MARPOL 73/78
Protocol is an agreement to prevent marine pollution caused by the
active substance in marine pollution.
[0017] The worldwide harbors are suffering by not only disturbance
of the marine ecosystem but also propagation of pathogens, caused
by the fact that more than 13 billion tons of ballast water are
transported each year and about 7,000 kinds of forbidden marine
living organisms are transported across ocean every day between
harbors.
[0018] For example, the ecosystem disturbance that occurred near
Chesapeake Bay in the US seriously damaged the sturgeon shark farm
around the bay, causing a damage recovery cost of over US $1
billion per year. It also adversely affected inside the Great
Lakes, causing a serious ecosystem disturbance such as the
extinction of some native species in the Great Lakes. These events
also played an ironic role in bringing about the United Nations
Convention on Biological Diversity (UNCCD).
[0019] The active substance in a ship must be discharged by
exchanging the ballast water at a distance of more than 20 mph from
the coast before entry into the destination port, wherein on the
open sea of the water depth of 500 m or more, three times of the
amount of existing ballast water must be exchanged, through which
more than 95% of the prohibited species must be removed.
[0020] FIG. 15 shows the Open Sea Emission Regulations (extract
from KBS TV).
[0021] As described above, the conventionally used ballast water
management system BWMS of the ship causes disturbance of the global
marine ecosystem due to the transportation of prohibited life
species. The energy consumption for ballast water exchange is 3 to
5% of the annual consumption of the ship, which is very costly. The
installation and maintenance cost of the processing apparatus for
treating the active substances is high. There is a danger that the
ship sinks during the ballast water exchange and there is a large
economic loss such as a decrease in the number of times of sailings
due to the time spent on the open sea for the ballast water
exchange.
[0022] In addition, due to the structure of the ballast water tank,
the structure of the ship is twisted. In order to prevent this
problem, the structure of the ballast water tank is strengthened by
steel structure, which increases the installation amount of the
steel structural member, and this increases the weight of the ship
hull structure. For these and other reasons, there were structural
and mechanical problems in ship structure.
DETAILED DESCRIPTION OF THE INVENTION
Technical Problem to be Solved
[0023] The present invention is devised for improving the drawbacks
of the prior art. The conventional ballast water management system
is composed as follows.
[0024] In ships, seawater is used for various purposes during
sailing. In order to use seawater, there is an inlet device (which
is called Seachest) for introducing seawater on the bottom or side
of the engine room. It is equipped with an open-close unit (valve).
When the open-close unit is closed, the watertight structure is
formed to prevent the seawater from entering the room. When the
open-close unit at the bottom is opened, seawater is introduced by
natural pressure, and seawater flows into the ballast water line by
the weight of the ship.
[0025] Pumps are installed in the machine room or the pump room to
cause the flow of seawater. Generally, electrically operated pumps
are used. Through the piping (piping and piping accessories)
connected to these pumps and the seawater inlet open-close unit,
the seawater is sent to the desired locations. Depending on the
application of seawater, various pumps such as ballast water pumps,
cooling water pumps, fire water pumps, mechanical unit water pumps,
residential water pumps, and bilge water pumps, etc. are used.
[0026] Depending on the purpose of the seawater, the ballast water
management system and the general-purpose seawater management
system have been operated in separately.
[0027] A ballast water storage tank is provided to store the
seawater in the structure of the double hull so as to make gravity
force forcing some of the ship to be submerged under water. The
ballast water storage tank comprises a bottom tank, a side tank, a
hopper side tank, a top side tank, or a wing tank etc. to fill the
ballast water. These terms are used to distinguish between top and
bottom of the ship when viewed vertically. The terms "bow tanks",
"central tanks" and "stern tanks" are used to distinguish the front
and rear of the ship. In ships with double hull structure, most of
ballast tanks except for bottom tanks are installed as one single
integral tank. When the water of the ballast water tank is
discharged, the uppermost space of the ballast water tank becomes
empty. When the check valve installed on the upper deck is operated
to control the water level of the ballast water tank, ballast water
is supplied to fill empty part of the ballast water tank.
[0028] In discharging the ballast water for loading cargo, the
open-close unit connected to the ballast water tank is opened and
the pump is operated to discharge it out of ship, and the discharge
pipe is installed on the side of the ship.
[0029] Conventional ship ballast water management apparatus
includes ballast water contaminated with transport-prohibited
living species. This has caused problems, such as marine ecosystem
disturbance.
[0030] In addition, the ship draws in seawater and uses it for
various purposes besides ballast water. Seawater mainly used for
machinery is used for engine coolant, generator coolant, main air
compressor coolant, stern tube lubricant coolant, boiler coolant,
etc. In order to use domestic or residential water such as fire
water, cleaning water, kitchen water, shower water etc., seawater
is changed to fresh water by using a fresh water generator, and a
storage tank for this purpose is also provided. For this reason,
seawater continues to flow in and out while the ship is
sailing.
[0031] Korean Patent No. 10-1206025 "a fresh water treatment system
of a ship" discloses a device for desalination process of
seawater.
[0032] Energy for drawing in seawater for ballast, machinery, and
desalination equipment (water purifier) for domestic water consumes
about 10% or more of the total energy consumed by the ship.
[0033] In general, in order to solve the problem, we must analyze
the interaction between the related factors. FIG. 16 is an
association chart analyzing the cause of the ecosystem disturbance
problem caused by the ballast water.
[0034] Through the association analysis of the problem, it was
found that the causes are as follows.
[0035] One cause is that the inflow of seawater containing
transport-prohibited living species.
[0036] Another cause is that the transport-prohibited species
contained in the inflowed seawater are mutated, grow, or generate
other toxic substances during the sailing of the ship, resulting in
increased contamination.
[0037] Yet another cause is that the ballast water with increased
contamination by the transport-prohibited life species during ship
sailing is discharged out of ship.
[0038] If the solution is derived based on only by eliminating each
cause separately, it is difficult to find out the potential cause
that is not easy to see, and it is difficult to obtain a
fundamental solution. The cause of the interaction between the
elements must also be derived.
[0039] In the integrated type ballast tank, ballast water is kept
isolated during ship sailing. This is yet another cause of the
increase of contamination of the ballast water due to mutations of
the transfer-prohibited life species or generating of toxic
substances, etc.
[0040] The best solution deduction method for solving the problem
is shown in FIG. 17.
[0041] Look for any way that minimize modifications in the existing
ship ballast water management system such that no materials that
cause marine ecosystem disturbances are discharged.
[0042] The best solution and the same proposition are summarized
below.
[0043] Minimal modifications are made to the existing ballast water
management system such as to discharge seawater with equal
conditions to those of the ballast water discharged area.
[0044] In order to solve the problem, we have to redefine the
solution of the problem as follows.
[0045] Regardless of the ballast water discharged area, seawater
should always be discharged in the same condition as those of the
discharged area. In order to achieve this, a plan is to be
implemented in which the ballast water of the ship is continuously
discharged and inflowed.
Technical Solution of the Invention
[0046] In order to accomplish the above object, the present
invention includes a plurality of ballast tanks having a
multilayered watertight bulkhead structure by modifying the
existing integrated ballast tanks. In the present invention, each
of the ballast tanks is provided with a water level sensor and a
water level control open-closed device (valve). The present
invention has piping and connectors for connecting to pumps for
supplying and discharging ballast water. The present invention
includes bypass valves for connecting adjacent ballast tanks to
each other in order to rapidly transmit ballast water to the
ballast tank located at the bottom of the tank. The present
invention includes an electronic control unit ECU that smoothly
controls inflow and discharge of ballast water. The present
invention has a seawater regulating device for regulating the water
level while discharging or inflowing water such as ballast water
and cooling water in accordance with the sailing conditions of the
ship.
[0047] Also, the volume of the existing ballast tanks should be
increased. That is, when setting Tbal-n (m) (normal ballast water
load line) after setting Tbal (m) (minimum planned ballast water
line), a part of the tanks that is not used as ballast tank is set
as to be used as a ballast tank. Thus, even if the ballast water is
discharged, space and devices are provided to maintain Tbal-n (m)
(normal ballast water load line). According to the present
invention, since the total volume of the ballast water tanks is
increased, the ship is more deeply submerged under water than the
conventional Tbal-n (m) (normal ballast water load line).
Effects of the Invention
[0048] As described above, the present invention relates to a
ballast water management apparatus for a ship of double hull
structure, and more particularly, to a ballast water management
apparatus when a cargo ship of double hull structure is sailed with
an empty storage state without loading cargo. The present invention
manages and controls an automatic regulating device so that the
ballast water is continuously and sequentially exchanged by using
seawater stored in a plurality of multi-layered ballast tanks as
cooling water and man-made water. In this way, it is possible to
integrate the dualized method for using seawater within the ship,
and to electronically and automatically manage and control the
ballast water.
[0049] In addition, all of the seawater, that is inflowed waters at
first, is discharged during ship sailing. Accordingly, seawater
having the same conditions as those of the sea in the port of entry
shall be discharged to the port of entry. As a result, there is an
effect of preventing the ecosystem disturbance caused by the
transport-prohibited life species in the ballast water.
[0050] Also, compared with that the conventional method in which
the energy used for storing and discharging the ballast water
corresponds to the net profit of the ship that is 3 to 5% of the
fuel used by the ship, the present invention can replace a part of
the energy for ballast water inflow and discharge with the energy
for cooling water and other water, which has the effect of
increasing the profit of the ship through energy saving.
[0051] Also, the ballast water is constantly exchanged during
ship's sailing. It therefore provides the effect of satisfying the
requirement that ballast water should be exchanged at a point 200
meters or more from the coast and at a depth of 500 meters or more.
As a result, the ship can enter the port without being anchored in
the outer port, thus increasing the number of ship sailings.
[0052] Further, since the present invention has ballast tanks
having a multi-layered watertight bulkhead structure, the stability
of the ship is improved, and as a result, the possibility of
sinking due to damage to the ship can be minimized and the ship
insurance cost can be reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] FIG. 1 is a flowchart illustrating an operation process of a
ballast water management method using an integrated seawater
management feature according to an embodiment of the present
invention.
[0054] FIG. 2 is a flowchart showing a conventional management
method of ballast water treatment.
[0055] FIG. 3 is a piping view showing seawater and fresh water
pipes conventionally used for various purposes.
[0056] FIG. 4 is a sectional view showing structure of a
conventional integrated type ballast water tank.
[0057] FIG. 5 is a cross-sectional view showing a multilayered
ballast tank according to an embodiment of the present
invention.
[0058] FIG. 6 is a block diagram showing a control element of an
electronic control unit ECU according to an embodiment of the
present invention.
[0059] FIG. 7 is a flowchart showing a method of managing and
integrating seawater of a ship.
[0060] FIG. 8 is an extract from the Korea Register of Shipping
Rules for the ballast water line and the load line in Korean
ships.
[0061] FIG. 9 is a correlation table of Dwt and ballast water
amount of a ship in general.
[0062] FIG. 10 is a sectional view of a general ballast water tank
structure.
[0063] FIG. 11 is a classification rule for general ballast water
load equipment.
[0064] FIG. 12 is a schematic diagram of a typical ballast water
tank arrangement.
[0065] FIG. 13 is a schematic diagram showing the method of ship
ballast water management recommended by MEPC (Marine Environment
Protection Committee) under IMO (International Maritime
Organization) of the United Nations.
[0066] FIG. 14 is a schematic view showing the transport-prohibited
life species.
[0067] FIG. 15 is a schematic view showing the pollutant discharge
regulations on the open sea.
[0068] FIG. 16 is an association chart analyzing the cause of the
ecosystem disturbance problem caused by the ballast water.
[0069] FIG. 17 is the best solution for problem solving.
DETAILED DESCRIPTION OF THE INVENTION
[0070] Hereinafter, the present invention will be described below
with reference to the accompanying drawings.
[0071] First, the structure of the automatic ballast water
regulating apparatus will be described below with reference to
FIGS. 1, 5, and 6.
[0072] The present invention comprises a plurality of ballast water
tanks having a multi-layered watertight bulkhead structure,
provided by modification of a conventional integral ballast tank
structurally modified,
[0073] additional ballast water tanks having watertight bulkhead
structure,
[0074] water level sensors for sensing water level of each of the
ballast water tanks,
[0075] open-close units (valves) for water level control,
[0076] piping and connectors for connecting to pumps,
[0077] bypass valves for transporting ballast water in a ballast
water tank to an adjacent ballast water tank,
[0078] piping and connectors for connection to cooling water and
water for other uses, and
[0079] an electronic control unit ECU that smoothly controls the
above elements, etc.
[0080] It is advantageous that the volume of the additional ballast
water tanks having the watertight bulkhead structure is the same as
that of the tanks for storing the seawater used as the cooling
water and the water for miscellaneous use.
[0081] The technique of the present invention has the effect of
automatically controlling the seawater according to various uses,
such as ballast water, cooling water, and miscellaneous use water
depending on the application.
[0082] Further, through the above-described technique, there is an
effect of fundamentally preventing the ecosystem disturbance
problem caused by the transport-prohibited life species, which is
not available in the conventional ship ballast water management
apparatus. The details will be described with reference to the
drawings.
[0083] When the cargo is not loaded, the inlet and outlet valves
11, 12, 13, and 14 of FIGS. 5 and 6 are opened and the pumps 22 and
24 are operated to save the ballast water up to the top tank of the
side tanks 102, and then the ship starts sailing. The level
detector 500 of FIG. 6 senses the water level and the controller
600 electronically controls various elements or devices.
[0084] Upon beginning of the sailing, a large amount of technical
water is required to operate the engine and various machinery. In
addition, and seawater for residential water and miscellaneous use
water will be continuously inflowed. The inflowed seawater is
either stored or used continuously by operations of pumps. The
seawater of the bottom ballast water tank 121 of FIG. 1 is used as
technical water such as cooling water and miscellaneous use water,
and then is discharged out of the ship by a drainage unit 400's
operation. When the seawater is discharged out of ship, the bottom
ballast water tank 121 is emptied. The water level at which the
ship is submerged under water reaches the original designed normal
ballast water loading line. At this time, the control unit 600
controls the bypass valve 62 of the un-emptied bottom ballast water
tank 121 to open, and the emptied ballast water tank is filled with
the seawater of adjacent ballast tank through the bypass valve. In
this way, the emptied tank is refilled by the seawater of the
adjacent side tank 123. When the top tanks of the side tanks are
sequentially emptied, the water level sensor 61 sends a signal to
the control unit so as to open the seawater inlet valves 11, 12,
13, 14, to activate the pumps, and to fill the top tanks, and then
to stop the pumps 22, 24, which are repeatedly performed. The time
taken for the seawater of each of the ballast water tanks to be
exchanged is designed to be from 30 minutes to about 90 minutes.
Through such continuous and sequential use of seawater, all of the
seawater is exchanged during ship's sailing.
[0085] In the method of using the ballast water treatment device in
some cases to processing active substances in seawater before
discharging, the discharged seawater is in a completely different
state from that of the seawater of the discharge sea area,
regardless of the method. Therefore, these method causes additional
problems.
[0086] In addition, the present invention technology is designed to
continuously and sequentially exchange the ballast water during the
ship's sailing. In the case of cargo ships sailing the ocean, the
ballast water is exchanged at open sea area of more than 20 miles
from the coast and the water depth exceeds 500 meters, so that not
only does it meet IMO regulations, but it also has the effect of
satisfying all USCG US Coast Guard regulations.
[0087] Further, according to the present invention, it is not
necessary to separately store seawater for various uses such as
ballast water, cooling water, and miscellaneous use water, since
the seawater stored in the ballast water tanks is used. As a
result, there is no need to use energy for storing or discharging
the ballast water, so there is fuel saving effect equivalent to
3.about.5% of ship fuel. This is the amount corresponding to the
net profit of ship sailing.
[0088] A ship equipped with a ballast water tank with multi-layered
watertight bulkhead structure will inflow seawater only into the
broken ballast tank even if the ship's shell is damaged by impact.
Therefore, there is an effect that the ship restoration is
remarkably superior to the restoring force at the time of breakage
occurring in a ship having the conventional integral type ballast
water tank.
[0089] In addition, those skilled in the art can understand that
various changes and modifications can be made therein without
departing from the subject matters of the disclosure. Thus, such
changes and modifications fall within the spirit and scope of the
disclosure.
REFERENCE NUMERALS
[0090] 10: fresh water storage tank, 11,12,13,14,15,16: open-close
unit (valve), 20: desalination device, 22,24: ballast water pump,
30: seawater treatment device, 50: integral type ballast water
tank, 52: supply pipe for mechanical devices water, 54: supply pipe
for residential water, 61: water level sensor of ballast water
tank, 62: bypass valve, 100: Sectional side view of a double hull
structural ship, 101: bottom, 102: hull outer wall, 104: sea
surface, 120: integral ballast water tank group, 121: bottom
ballast water tank, 122: integral side ballast water tank, 150:
discharge pipe, 400: drainage unit, 500: water line sensor, 600:
electronic control device.
* * * * *