FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
“SHIP STRUCTURE”
MITSUBISHI HEAVY INDUSTRIES, LTD., a Japanese company, of 16-5,
Konan 2-chome, Minato-ku, Tokyo 1088215, JAPAN; and HITACHI,
LTD., a Japanese company, of 6-6, Marunouchi 1-chome, Chiyoda-ku,
Tokyo 1008280, JAPAN
The following specification particularly describes the invention and the manner in which it is to be
performed.
DESCRIPTION
~~33EL STRUC~U~E
Technical Field
[0001]
The present invention relates to vessel structures
including ballast-water treatment apparatuses for treating
,
vessels' ballast water to, for example, eliminate or killl
microorganisms contained therein.
Background Art
[0002]
Vessels' ballast water, essential for safety vessel
navigation, is seawater or freshwater loaded into ballast
tanks to control the attitude of the hull and ensure its
stability. The ballast water is pumped and loaded (taken up)
into the ballast tanks when the vessel is empty of cargo and
is discharged (released) at a loading port as the loading
proceeds.
The ballast water, described above, contains various
species of microorganisms (aquatic organisms). These
microorganisms include minute organisms (e.g., microorganisms
such as bacteria and suspended organisms such as plankton), as
well as, for example, fish eggs and larvae.
[0003]
Because the ballast water is released at a port (body of
water) different from the loading point, the microorganisms
transferred together with the ballast water, if they settle in
the new environment, might affect the ecosystem of that body
of water and economic activities such as fishery. Some of the
pathogens transferred together with the ballast water might
directly affect human health .
.
Accordingly, the International Maritime Organization
(IMO) is calling for the ratification of a convention
concerning the management of microorganisms contained in
ballast water, which calls for eliminating or killing
microorganisms when ballast water is taken up or released.
[0004]
An apparatus proposed for eliminating or killing
microorganisms in ballast water is a liquid-bornemicroorganism
killing apparatus that passes ballast water
through a slit plate provided in a flow channel at a
predetermined flow rate or more to destroy and kill liquidborne
microorganisms by means of a shearing phenomenon (abrupt
difference in flow rate between different sites) occurring
inside the flow disturbed through the slit. Another liquidborne-
microorganism killing apparatus has been proposed that
includes front and back slit plates with a shift in slit
position that allows microorganisms surviving the shearing
through the front slit plate to be destroyed and killed by
means of an impact pressure caused when cavitation bubbles
produced by the front slit plate collapse on the back slit
plate (see, for example, Patent Document 1).
Patent Document 1:
Japanese Unexamined Patent Application, Publication No.
2003-200156
Disclosure of Invention
[0005]
The above ballast-water treatment apparatuses are
required to have high throughputs (e.g., about 7,000 m3/hr for
large oil tankers) because they treat ballast water taken up
or released substantially at the same time as cargo handling
proceeds. Accordingly, there is a tendency to increase the
size of the ballast-water treatment apparatuses themselves,
and it is difficult to secure an appropriate installation site
for such ballast-water treatment apparatuses in a vessel for
the following reasons.
[0006]
(1) It is preferable to install a ballast-water treatment
apparatus inboard, rather than outboard, such as on the deck,
in view of corrosion resistance against ocean waves and wind
and rain in a marine environment because the apparatus is
required to reach a high treatment level involving the use of,
for example, electricity or chemicals.
(2) If the ballast-water treatment apparatus is installed
inboard, it is desirable to install the apparatus at the bow
or stern, rather than in the midship section, in view of, for
example, ensuring sufficient cargo-loading capacity and the
presence of a hazardous section loaded with combustible cargo.
(3) In a typical vessel design, equipment such as a
I •
ballast pUmp is insta11ed in an engine room at the stern. If
the ballast-water treatment apparatus is installed at the bow,
therefore, extended piping is needed from an intake port
provided near the ballast pump at the stern to the bow.
[0007]
Therefore, there is a demand for a vessel structure that
allows a ballast-water treatment apparatus, which will become
mandatory, to be installed without the need for a substantial
change in hull design and that can readily be applied not only
to newly built vessels, but also to existing vessels with some
adaptation. That is, there is a demand for a vessel structure
that allows many different types of ballast-water treatment
apparatuses to be readily- installed at an appropriate inboard
site in many different types of vessels (particularly,
commercial vessels) such as tankers (e.g., LPG carriers, LNG
carriers, and oil carriers), cargo ships (e.g., container
ships, roll-on/roll-off ships, and general cargo ships), and
5
specialized vessels (bulk carriers, ore carriers, and car
carriers) irrespective of whether they are installed in newly
built vessels or existing vessels.
An object of the present invention, which has been made
in light of the above circumstances, is to provide a vessel
structure that allows many different types of ballast-water
treatment apparatuses to be readily installed at an
appropriate inboard site in many different types of vessels.
[0008]
To solve the above problems, the present invention~
"
employs the following solutions.
A vessel structure according to the present invention
includes a ballast-water treatment apparatus for treating
ballast water to eliminate or kill microorganisms therein when
the ballast water is taken up or released. The ballast-water
treatment apparatus is disposed in a steering gear room at the
rear of the vessel.
[0009]
Because the ballast-water treatment apparatus is disposed
in the steering gear room at the rear of the vessel, this
vessel structure allows various ballast-water treatment
apparatuses to be readily installed while effectively
utilizing the inner space of the vessel without a substantial
change in hull structure and shape.
[0010]
6
In the above vessel structure, the ballast-water
treatment apparatus is preferably disposed on a deck provided
in an inner space of the steering gear room. This allows
various ballast-water treatment apparatuses to be installed
while utilizing the inner space of the steering gear room more
effectively, that is, utilizing the space effectively in three
dimensions.
[0011]
.
In the above vessel struature, a stern void space such as
an aft peak tank is preferably used as a buffer tank of the
ballast-water treatment apparatus. This eliminates the need
to newly install a buffer tank for a ballast-water treatment
apparatus of a type requiring a buffer tank.
[0012]
The above vessel structure of the present invention
allows a ballast-water treatment apparatus, which will become
mandatory, to be installed without the need for a substantial
change in hull design and shape and, additionally, allows many
different types of ballast-water treatment apparatuses to be
readily installed in many different types of vessels
irrespective of whether they are installed in-newly built
vessels or in existing vessels with some adaptation.
Brief Description of Drawings
[0013]
[FIG. 1] Fig. 1 is an enlarged view of a stern section
of a vessel including a ballast-water treatment apparatus as
an embodiment of a vessel structure according to the present
invention.
[FIG. 2] Fig. 2 is an intake system diagram of the
ballast-water treatment apparatus.
[FIG. 3] Fig. 3 is a release system diagram of the
ballast-water treatment apparatus.
[FIG. 4] Fig. 4 is a diagram showing an example of the
overall configuration of an LNG carrier as an example of a
vessel structure.
Explanation of Reference Signs:
[0014]
1: LNG carrier
4: stern section
6: ballast tank
7: accommodation area
8: engine room
9: steering gear room
10: void
12: intake port
12': buffer-tank intake port
13: ballast pump
13': treated-water transfer pump
14: ballast-water piping system
v
15: treatment-apparatus inlet piping system (including
treatment-apparatus vessel connect piping)
16~ treatment-apparatus outlet piping system
16': treated-water transfer piping system
17: release port
20: ballast-water treatment apparatus
30: deck
40: draft line
Best Mode for-Carrying Out the Invention
[0015]
An embodiment of a vessel structure according to the
present invention will now be described with reference to the
drawings.
Fig. 4 is a diagram showing the hull structure of an LNG
carrier 1 as an example of a vessel structure. This LNG
carrier 1 is divided into a bow section 2, a midship section
3, and a stern section 4 in this order from the front of the
hull.
The bow section 2 is a section positioned in the front of
the LNG carrier 1 in the sailing direction and including, for
example, a bow-section store. The midship section 3, disposed
behind the bow section 2, has a plurality of (three in the
example shown) LNG tanks 5 arranged along the hull axis. The
midship section 3 also has a plurality of separated ballast
tanks 6 provided in spaces formed around the bottom of the
spherical LNG tanks 5 to the left and right of the hull.
[0016]
As shown in Fig. 1, for example, the stern section 4,
disposed behind the midship section 3, includes an
accommodation area 7, an engine room 8, a steering gear room
9, and a void 10. In the drawing, reference sign 11 indicates
a propeller for vessel propulsion provided at the stern of the
.LNG carrier 1.
The accommodation area 7 is a space disposed above the
front of the stern section 4 and including, for example, a
wheelhouse and a crew compartment of the LNG carrier 1.
The engine room 8 is a space disposed below the
accommodation area 7 and accommodating various machinery and
equipment such as an engine serving as a driving source for
the propeller 11 and power generation equipment for generating
power used in the LNG carrier 1.
The steering gear room 9 is a space disposed behind the
top of the engine room 8 and accommodating, for example,
machinery and equipment (steering gear) for driving a rudder
(not shown) of the LNG carrier 1.
The void 10, a space formed below or in front of the
steering gear room 9, is a narrow space because the vessel
width is narrowed at the bottom of the stern section 4. The
void 10 is optionally used as, for example, an installation
10
space for an aft peak tank.
[0017]
A ballast-water treatment apparatus 20 is disposed at an
appropriate site in the above LNG carrier 1. The ballastwater
treatment apparatus 20 is an apparatus for eliminating
or killing various species of microorganisms contained in
ballast water loaded into the ballast tanks 6 to control the
attitude of the hull and ensure its stability. That is, the
ballast-water treatment apparatus 20 is an apparatus in which
ballast water, which is taken'up into the ballast tanks 6
depending on, for example, the loading conditions and which is
released as the amount of cargo loaded is increased, is
treated when taken up or released so that it can be released
with microorganisms contained therein eliminated or killed~
thereby preventing microorganisms inhabiting the vicinity of a
port where the water is taken up from being released into
another body of water and thus affecting its ecosystem.
[0018]
The above ballast-water treatment apparatus 20 is
disposed in the steering gear room 9 of the stern section 4,
which forms the rear of the vessel.
The ballast-water treatment apparatus 20 shown in Fig. 1
includes a first treatment unit 21 and a second treatment unit
22. In this case, the first treatment unit 21 and the second
treatment unit 22 are a pair of units into which the necessary
\I
treatment capability is divided, and both units are disposed
in the steering gear room 9. The type of ballast-water
treatment apparatus 20 is not limited to the configuration in
which it is divided into the first treatment unit 21 and the
second treatment unit 22, and it may be appropriately changed
depending on the type of treatment and various conditions.
[0019]
In Fig. 1, reference sign 12 indicates an intake port for
ballast wa~er, and 13 lndicates a ballast pump. The ballast
water taken up through the intake port 12 is supplied into the
ballast tanks 6 via a ballast-water piping system 14.
The ballast-water treatment apparatus 20 is coupled via a
treatment-apparatus inlet piping system (including treatmentapparatus
vessel connect piping) 15 and a treatment-apparatus
outlet piping system 16 to the ballast-water piping system 14
for supplying the ballast water taken up through the intake
port 12 into the ballast tanks 6.
Figs. 2 and 3 are piping system diagrams showing an
example of the configuration of the ballast-water treatment
apparatus 20, the ballast-water piping system 14 for supplying
ballast water from the intake port 12 into the ballast tanks 6
by operating the ballast pump 13, and the treatment-apparatus
inlet piping system (including treatment-apparatus vessel
connect piping) 15 and the treatment-apparatus outlet piping
system 16 coupling together the ballast-water treatment
}2-
apparatus 20 and the ballast-water piping system 14. In Figs.
2 and 3, reference sign 17 indicates a release port for the
ballast water, VI to V7 indicate open/close valves, and eVl
indicates a check valve.
[0020]
In the example of the piping system in Figs. 2 and 3, the
ballast-water treatment apparatus 20 is configured as a single
unit. Fig. 2 illustrates an intake flow, whereas Fig. 3
illustrates a release flow.
When ballast water is taken up, as shown in Flg. 2, the
ballast water is taken in through the intake port 12 by
operating the ballast pump 13. The ballast water taken in
through the intake port 12 flows into the ballast pump 13 via
a ballast water pipe 14a, with the open/close valve VI open,
and via a ballast water pipe 14b. The ballast water is pumped
by the ballast pump 13 and is supplied into the ballast-water
treatment apparatus 20 via the ballast water pipe 14b, which
has the check valve eVl, and a treatment-apparatus inlet pipe
15a.
[0021]
The check valve eVl described above permits only a flow
in the direction from the ballast pump 13 toward the ballastwater
treatment apparatus 20 (the direction indicated by the
arrows shown). When the ballast water is taken up,
additionally, the open/close valve V6 provided in the
treatment-apparatus inlet pipe 15a is open, whereas the
open/close valve V2, provided in a ballast water pipe 14c, the
open/close valve V3, provided in a ballast water pipe 14f, and
the open/close valves V4 and V5, provided in a ballast water
pipe 14g, are all closed. The ballast water supplied into the
ballast-water treatment apparatus 20 is subjected to treatment
for eliminating or killing microorganisms contained in the
ballast water and is then loaded into the ballast tanks 6 via
the open/close valve V7, the treatment-appara!tus outlet piping
16,'a ballast water pipe 14d, and a ballast water pipe 14e.
Accordingly, the ballast water is loaded into the ballast
tanks 6 with the microorganisms eliminated or killed.
If the ballast-water treatment apparatus 20 uses a buffer
tank, the buffer tank is coupled by replacing the treatmentapparatus
outlet piping system 16 with a buffer-tank intake
port 12', a treated-water transfer pump 13', and a treatedwater
transfer piping system 16'; the flow of ballast water is
changed only in that portion.
[0022]
Next, referring to Fig. 3, the release of the ballast
water will be described. When the ballast water is released,-
the open/close valves VI, V6, and V7 are changed from being
open to being closed, whereas the open/close valves V3, V4,
and V5 are changed from being closed to being open.
When the ballast water is released, as shown in Fig. 3,
the ballast water is taken in from the ballast tanks 6 by
operating the ballast pump 13. The ballast water taken in
from the ballast tanks 6 flows into the ballast pump 13 via
the ballast water pipe 14e, via the ballast water pipe 14f,
with the open/close valve V3 open, and via the ballast water
pipe 14b. The ballast water is pumped by the ballast pump 13
and is released outside from the release port 17 via the
ballast water pipe 14b, which has the check valve eVl, and via
the ballast water pipe 14g, which has the open/close valves Vi
and V5.
[0023]
Thus, if the ballast water is subjected to the treatment
for eliminating or killing the microorganisms in the ballast
water when taken up, it is possible to assume that
substantially no microorganisms inhabit the ballast water
loaded into the ballast tanks 6. Accordingly, if the LNG
carrier 1, carrying the ballast water, sails to a loading port
where the ballast water is released outside as the loading
operation proceeds, it does not affect the ecosystem of the
body of water around the loading port.
Although the microorganisms are treated with the ballastwater
treatment apparatus 20 when the ballast water is taken
up in the above description, they may instead be treated when
the water is released.
[0024]
IS
The ballast-water treatment apparatus 20 described above
is installed in the steering gear room 9 at the rear of the
LNG carrier 1. The ballast-water treatment apparatus 20 is
required to have high throughput and is therefore increased in
size because it treats ballast water taken up or released as
cargo handling proceeds. Accordingly, a large space is
required to install the ballast-water treatment apparatus 20.
Although the need for such a large installation space
currently remains the same, many different conditionJ. (e.g.,
shape) are ~emanded of the installation space because there
are various types of ballast-water treatment apparatuses 20.
[0025]
A typical vessel such as the LNG carrier 1 has the.
propeller 11 and the propulsion engine at the rear of the
hull. The ballast pump 13 is therefore installed in the
engine room 8 at the rear of the hull unless there are
exceptional circumstances. Hence, it is desirable to install
the ballast-water treatment apparatus 20 near the ballast pump
13 to limit an increase in piping length and piping
installation space.
On the other hand, because the steering gear room 9 is
adjacent to the engine room 8 and is also located directly
above the propeller 11 and the rudder, the steering gear room
9 has a relatively large space as a measure against, for
example, vibrations resulting from the operation of such
I
J
equipment. Hence, a large installation space in which the
ballast-water treatment apparatus 20 can be installed can
readily be ensured in the steering gear room 9. That is, the
space required to install the ballast-water treatment
apparatus 20 can readily be ensured in the steering gear room
9 without a substantial change in hull structure and shape.
[0026]
Specifically, the space in the steering gear room 9 is
.
usually left as a site (space) that is not appropriate for
installation of equipment because of the vibration problem
described above. The ballast-water treatment apparatus 20,
however, can be used in the absence of the above vibrations
because it is mainly used while the LNG carrier 1 is anchored
or berthed. Focusing on the above vessel structure, the
inventors have found that the steering gear room 9 is ideal as
the installation site for the ballast-water treatment
apparatus 20.
That is, because the ballast water is taken up or
released while the vessel is anchored or berthed at a port for
cargo handling, the engine for vessel propulsion and the
rudd~r are not driven during the operation of the ballastwater
treatment apparatus 20. No consideration is therefore
needed as to ambient variations in the steering gear room 9
during the operation of the ballast-water treatment apparatus
20, and the steering gear room 9 is ideal as the installation
site for the ballast-water treatment apparatus 20. The
treatment may also be performed during a voyage if necessary;
such a case is not out of the question.
[0027]
It might be possible to install the ballast-water
treatment apparatus 20 in the engine room 8 from the viewpoint
of installing it near the ballast pump 13. In a typical
vessel design, however, the interior of the engine room 8 is
used as a site for installation of various equipment in view
of ease of maintenance and handring unless there are
exceptional requirements. Indeed, there is substantially no
extra space in the engine room 8 because it is configured in
view of ease of passage and operation and only has the minimum
space required for installation and maintenance of equipment.
Hence, installing the ballast-water treatment apparatus 20 in
the engine room 8 would necessitate a substantial change in
hull structure and shape, such as changing the hull design so
as to make the engine room 8 larger.
In particular, if this approach were applied to an
existing vessel, installing the ballast-water treatment
apparatus 20 by adapting the engine room 8 would require
substantial adaptation to the hull structure. Because such
adaptation would involve increased costs and extended working
time, the use of the engine room 8 as the installation site
for the ballast-water treatment apparatus 20 causes numerous
\0
problems and is extremely difficult.
[0028]
The steering gear room 9 is advantageous in view of
accessibility for operation etc. because it is close to the
crew accommodation area 7 disposed above the engine room 8.
From this viewpoint, the steering gear room 9 is suitable as
the installation site for the ballast-water treatment
apparatus 20.
The steeringlgear room 9 needs no measure against
corrosion due to ocean waves and wind and rain in a marine
environment because it is an inboard space. From this point,
the steering gear room 9 is suitable as the installation site
for the ballast-water treatment apparatus 20.
[0029]
Because the steering gear room 9 has a relatively large
upper space above the steering gear, as shown in Fig. 1, for
example, the ballast-water treatment apparatus 20 can be
installed on a deck 30 formed at, for example, a middle
position in the space. Such a configuration allows the inner
space of the steering gear room 9 to be effectively utilized
in three dimensions. As shown in 4ig. 1, for example, this
facilitates a divided structure in which the first treatment
unit 21 is installed on the deck 30 while the second treatment
unit 22 is installed on the floor of the steering gear room 9.
Thus, flexible adaptation to various conditions is permitted
\9
in the installation of various types of ballast-water
treatment apparatuses 20 differing in structure, shape, etc.
Although the first treatment unit 21 is installed on the
deck 30 in the exemplary configuration shown in Fig. 1, the
invention is not limited thereto.
[0030]
In the case where the ballast-water treatment apparatus
20 is of a type requiring a buffer tank, if it is installed in
the steering gear room 9, the aft peak tank, for example,
installed in the nearby void 10 can be used as abutTer tank.
Such a configuration allows the space in the void 10 to
be effectively utilized to readily ensure the installation
space for the buffer tank. That is, even the void 10, which
is located at the bow and therefore has a complicated shape,
can be effectively utilized without the constraints of spatial
shape because the buffer tank is merely a tank for storing the
ballast water.
For an open-to-air ballast-water treatment apparatus 20,
installation at or below a vessel draft line 40 should be
avoided, for structural reasons, to prepare for the worst. On
the other hand, installing the ballast-water treatment
apparatus 20 at the same level or above the top of the ballast
tanks 6 while using an existing ballast pump 13 is inefficient
because it requires additional modifications such as
increasing the pumping pressure of the ballast pump 13. For
an open-to-air ballast-water treatment apparatus 20,
therefore, it is extremely reasonable to install it in the
steering gear room 9, which is located above the vessel draft
line 40 and below the top of the ballast tanks 6.
[0031]
The above vessel structure of the present invention thus
allows the ballast-water treatment apparatus 20, which will
become mandatory, to be installed without the need for a
substantial change in hull!design and shape and, additionally,
allows many different types of ballast-water treatment
apparatuses to be readily installed in many different types of
vessels irrespective of whether they are installed in newly
built vessels or in existing vessels with some adaptation.
That is, the present invention is based on the finding that
the space in the steering gear room 9, which is required for a
vessel structure but has little configurational constraint and
little effect on the rest of the vessel structure, can be
effectively utilized, serving as the ideal installation site
for the ballast-water treatment apparatus 20 in the vessel
structure.
[0032]
Because the steering gear room 9 is adjacent to the
engine room 8, in which the ballast pump 13 is installed, a
shorter piping length and a smaller piping installation space
are required for the treatment-apparatus inlet piping system
(including treatment-apparatus vessel connect piping) 15 and
the treatment-apparatus outlet piping system 16, and a
pressure loss accompanying the ballast water treatment can
also be minimized.
Another advantage is that various control devices and
electrical devices have fewer constraints because the steering
gear room 9 is not an explosion-proof area.
A further advantage is that the ballast water can readily
be released outside in an emergency because the steering gear
room 9 is located above the vessel draft.
The present invention is not limited to the above
embodiment and can be appropriately changed without departing
from the spirit of the present invention.
We Claim
1. A vessel including a ballast-water treatment apparatus
(20) for treating ballast water to eliminate or kill
microorganisms therein when the ballast water is taken up or
released, wherein the ballast-water treatment apparatus (20)
is disposed at the rear of a non-explosion proof area.
2. The vessel as claimed in claim 1, wherein a steering
gear room (9) is the non-explosion proof area.
3. The vessel as claimed in claim 2, wherein the steering
gear room (9) is adjacent to an engine room (8), in which a
ballast pump (13) is installed.
4. The vessel as claimed in claim 1, wherein the ballastwater
treatment apparatus (20) is located above a vessel
draft line (40).