SHIP OR BARGE BASED COMPRESSED GAS TRANSPORT SYSTEM

NAVIRE OU BARGE DESTINE AU TRANSPORT DU GAS COMPRIME

English Abstract

A marine gas storage and transport system formed of small diameter steel pipe, which is stacked horizontally in a hexagonal pattern. The system is suitable for use on top of a barge or inside the holds of a ship. The horizontal hexagonal stacking and the use of small diameter pipe permit large stacking heights to be reached without over- stressing the pipes at the bottom of the stack. The pipes are laid down in long straight lengths and are manifolded in groups of two (2) and seven (7) at their ends by a unique system that space-wise still permits the hexagonal stacking arrangement and also allows for about 33% (thirty three percent) of the system to be continuously inspected by a pig. Each group of seven can be connected to another group of seven and so also can the groups of two. Thus very large volume storage units can be constructed cheaply and efficiently. In addition when the pipes are stored within the holds of an ocean going ship a transverse watertight bulkhead is created approximately every 20 to 50 meters by infilling the spaces between the pipes with a watertight material. Since the spaces are small the force from the water head is low and the required longitudinal water-tightness can be provided by a number of materials ranging from silicone to epoxy products. This is a unique component of the invention as it precludes the expensive necessity of providing multiple penetrations through a standard watertight bulkhead.

French Abstract

Système de stockage et de transport de gaz marin formé d'un tuyau en acier de petit diamètre, qui est empilé horizontalement en motif hexagonal. Le système est approprié pour être utilisé sur une barge ou dans la cale d'un navire. L'empilement horizontal hexagonal et l'utilisation d'un tuyau en acier de petit diamètre permettent d'atteindre des hauteurs d'empilement élevées sans imposer de contrainte trop importante aux tuyaux situés à la base de l'empilement. Les tuyaux sont étendus sous la forme de longues files droites et sont raccordés à un collecteur par groupes de deux (2) et de sept (7) à leurs extrémités par un système unique qui permet toujours, dans l'espace, l'agencement par empilement hexagonal et qui permet également à environ 33 % (trente-trois pour cent) du système d'être inspectés en continu par un racleur. Chaque groupe de sept peut être raccordé à un autre groupe de sept et il en est de même pour les groupes de deux. Ainsi, des unités de stockage de très grand volume peuvent être construites efficacement et à bas coût. De plus, lorsque les tuyaux sont stockés dans la cale d'un navire naviguant sur l'océan, une cloison transversale étanche est créée approximativement tous les 20 à 50 mètres par remplissage des espaces entre les tuyaux avec un matériau étanche à l'eau. Puisque les espaces sont petits, la force de la chute d'eau est faible et l'étanchéité à l'eau longitudinale peut être assurée par un certain nombre de matériaux allant de la silicone aux produits époxydes. Il s'agit d'un composant unique de l'invention puisqu'il élimine la nécessité coûteuse de former de multiples pénétrations à travers une cloison étanche standard.

Claims

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THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A containment structure, comprising:
a cluster of seven pipes arranged side by side in a hexagonal cross-sectional
pattern with a central pipe surrounded by six outer pipes, each of the outer
pipes making
linear contact with each of two adjacent outer pipes and the central pipe, the
cluster of
seven pipes having first and second ends; and
a first manifold at one end of the cluster of seven pipes connecting each of
the
seven pipes into fluid communication with a connector pipe.
2. The containment structure of claim 1 in which the connector pipe is formed
of an
extension of the central pipe.
3. The containment structure of claim 2 in which the outer pipes are coned at
the
first end of the cluster of seven pipes.
4. The containment structure of claim 3 in which the manifold comprises:
a plate having apertures to which the coned outer pipes and central pipe are
secured;
a hemispherical shell secured to the plate around an outer periphery of the
plate; and
the connector pipe extending from the hemispherical shell.
5. The containment structure of claim 1 in which a second manifold is provided
at
the second end of the cluster of seven pipes, the second manifold connecting
each of the
seven pipes into fluid communication with a second connector pipe.
6. A transportation storage system, comprising:
a deck;
plural clusters of seven pipes supported by the deck, each cluster of seven
pipes
being formed as defined in claim 1 and supported by each other in a hexagonal
stacking
pattern;

8
each of the connector pipes being interconnected to place each of the pipes in
fluid communication with each other.
7. The transportation storage system of claim 6 further comprising plural
pairs of
pipes manifolded together and interspersed with the plural clusters of seven
pipes, the
plural pairs of pipes being interconnected with the connector pipes.
8. The transportation storage system of claim 6 in which the transportation
system is
ship based.
9. The transportation storage system of claim 7 in which the deck is in the
hold of a
ship.
10. The transportation storage system of claim 9 in which the pipes extend the
length
of the ship.
11. The transportation storage system of claim 6 in which, in each cluster,
the
connector pipe is formed of an extension of the central pipe.
12. The transportation storage system of claim 6 in which, in each cluster,
the outer
pipes are coned at the first end of the cluster of seven pipes.
13. The transportation storage system of claim 12 in which, in each cluster,
the
manifold comprises:
a plate having apertures to which the coned outer pipes and central pipe are
secured;
a hemispherical shell secured to the plate around an outer periphery of the
plate;
and
the connector pipe extending from the hemispherical shell.

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14. The transportation storage system of claim 6 in which a second manifold is
provided at the second end of each cluster of seven pipes, each second
manifold
connecting each of the corresponding seven pipes into fluid communication with
a
corresponding second connector pipe.
15. The transportation storage system of claim 6 in which gaps between the
pipes are
sealed with seals at periodic intervals along the pipes to form bulkheads.
16. The transportation storage system of claim 7 in which gaps between the
pipes are
sealed with seals at periodic intervals along the pipes to form bulkheads.
17. A containment structure, comprising:
a cluster of at least three pipes arranged side by side in a triangular cross-
sectional
pattern, each of the pipes making linear contact with each other, the cluster
of at least
three pipes having first and second ends; and
a first manifold at one end of the cluster of at least three pipes connecting
each of
the at least three pipes into fluid communication with a connector pipe.
18. The containment structure of claim 17 in which the pipes are coned at the
first end
of the cluster.
19. The containment structure of claim 17 in which the manifold comprises:
a plate having apertures to which the pipes are secured;
a hemispherical shell secured to the plate around an outer periphery of the
plate;
and
the connector pipe extending from the hemispherical shell.
20. A transportation storage system, comprising:
a deck;
plural clusters of pipes supported by the deck, each cluster of pipes being
formed
as defined in claim 17 and supported by each other in a stacking pattern;

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each of the connector pipes being interconnected to place each of the pipes in
fluid communication with each other.

Description

CA 02283008 1999-09-22
1
TITLE OF THE INVENTION:
Ship or Barge Based Compressed Gas Transport System
NAME(S) OF INVENTOR(S):
P. John Fitzpatrick
David G. Stenning
James A Cran
FIELD OF THE INVENTION:
This invention relates to apparatus and methods for the marine transport and
storage of compressed natural gases.
BACKGROUND OF THE INVENTION:
This invention is an improvement on the technology disclosed in US patents
nos.
5,839,383 and 5,803,005. The invention relates particularly to the marine gas
transportation of non-liquefied compressed gas. Because of the complexity of
existing
marine gas transportation systems significant expenses are uncurred which
render many
projects uneconomic. Thus there is an ongoing need to design storage systems
for
compressed gas that can contain large quantities of compressed gas, simplify
the system
of complex manifolds and valves, and also reduce construction costs. It is an
object of the
present invention to do all three.
SUMMARY OF THE INVENTION:
A gas storage system, particularly adapted for the transportation of large
quantities of compressed gas on board a ship (within its hold) or on board a
simple barge

CA 02283008 2006-10-13
2
(above or below its deck), primarily by means of simply manifolded long,
straight sections
of small diameter steel pipe. The pipe in general runs the length of the barge
or the ship in
continuous straight sections. The pipe, generally smaller than 300mm, is
stacked in a
hexagonal pattern to reduce stresses and is manifolded at the ends in a manner
that does not
interfere with the hexagonal stacking, even at the ends. Hexagonal stacking
produces a
hydrostatic type loading in the pipes and results in much lower bending and
buckling
stresses than are seen under direct or linear stacking. This combination of
manifolding and
stacking is a feature of the invention. Another feature of the invention
relates to the easy
provision of a transverse watertight barrier when the pipes are stored within
the holds of a
ship or barge. All ships require transverse water-tightness at discrete
intervals along the ship
length for safety and floatation reasons. Since the gaps between the small
diameter pipes are
small water-tightness can be achieved by filling these gaps at discrete
intervals, normally
about 20 to 50 meters depending on the ships overall size, with a product that
can withstand
a full head of water. This could be a silicone; epoxy or urethane based
product. As such the
requirement for expensive bulkhead penetrations is not required and the pipes
can maintain
their straightness and close hexagonal contact throughout the length of the
ship.
Certain exemplary embodiments can provide a containment structure, comprising:
a
cluster of seven pipes arranged side by side in a hexagonal cross-sectional
pattern with a
central pipe surrounded by six outer pipes, each of the outer pipes making
linear contact
with each of two adjacent outer pipes and the central pipe, the cluster of
seven pipes having
first and second ends; and a first manifold at one end of the cluster of seven
pipes
connecting each of the seven pipes into fluid communication with a connector
pipe.
Certain other exemplary embodiments can provide a transportation storage
system,
comprising: a deck; plural clusters of seven pipes supported by the deck, each
cluster of
seven pipes being formed as defined above and supported by each other in a
hexagonal
stacking pattern; each of the connector pipes being interconnected to place
each of the pipes
in fluid communication with each other.
Still certain other exemplary embodiments can provide a containment structure,
comprising: a cluster of at least three pipes arranged side by side in a
triangular cross-
sectional pattern, each of the pipes making linear contact with each other,
the cluster of at

CA 02283008 2006-10-13
2a
least three pipes having first and second ends; and a first manifold at one
end of the cluster
of at least three pipes connecting each of the at least three pipes into fluid
communication
with a connector pipe.
Yet another exemplary embodiment can provide a transportation storage system,
comprising: a deck; plural clusters of pipes supported by the deck, each
cluster of pipes
being formed as defined above and supported by each other in a stacking
pattern; each of the
connector pipes being interconnected to place each of the pipes in fluid
communication with
each other.
The gas storage system of the present invention has many advantages. First,
the pipe
diameter is small and the severity of failure is greatly reduced. Possibly
also the probability
of failure is also reduced. Second, the technology for the production of long
straight lengths
of small diameter pipe is well known and inexpensive. Third, approximately 33%
of the
system is continuously inspectable by means of an internal pig. Fourth,
complicated design
features are absent and the manifolds at the ends are simple in nature. Fifth,
the idea of
manifolding multiple units of small pipe together (approximately seven) to
produce a larger
type bottle unit greatly reduces the severity of failure since little energy
is dissipated by the
fracture of a small diameter pipe. Also the incidence of fracture of small
diameter pipe in
controlled environments is virtually non existent. All these features lead to
great cost
reductions.
Other features and advantages of the invention become apparent when viewing
the
drawings and upon reading the detailed description.

CA 02283008 1999-09-22
3
BRIEF DESCRIPTION OF THE DRAWINGS:
The preferred embodiments of the invention will now be described, with
reference
to the drawings, by way of illustration only and not with the intention of
limiting the
scope of the invention, in which like numerals denote like elements and in
which:
Fig. 1 shows an elevation of a typical barge with the gas storage system on
top of
the deck of the barge;
Fig.2 is an enlarged cross-sectional view of Fig.l;
Fig.3 is an enlarged detail showing an end elevation of the hemi-spherical
manifolding system and the hexagonal stacking of the pipes;
Fig.4 is an end elevation of a group of seven pipes. Six of which are tapered
or
coned into the hemispherical manifold. The central pipe is not tapered;
Fig.5 is a longitudinal plan cross-section of the end system shown in Fig.4;
Fig.6 is a cross-section of an oceangoing double-hulled ship without
transverse
bulkheads, showing the small diameter pipes in cross-section (only a portion
of the pipes
is shown); and
Fig.7 is an enlargement of the pipe detail showing how water-tightness can be
achieved at discrete intervals along the ships length.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS:
Referring now to the drawings, where corresponding similar parts are referred
to
by the same numerals throughout the different figures, the preferred
embodiments are
now described. It is also understood that the material employed to make the
pipe and its
connections will be ductile and not brittle at the proposed operating
temperatures. The
pipe and its connections may be fabricated from normal grade steel typically
X70.
Fig 1 depicts a side elevation 10 of a typically simple barge with a DWT
capacity
of typically around 10,000 to 20,000 Tonnes. The CNG storage system is shown
covered
12 on the deck of the barge. It is also possible to put the pipe on the deck
and have it
exposed to the elements as long as the CNG system is adequately protected from
the
corrosive effects of the elements. Also the barge may or may not be self
propelled. The
advantage of storing the system on the deck means that the barge does not need
any
unusual geometry or strengthening within it's holds and it can be easily
constructed and

CA 02283008 1999-09-22
4
towed to the pipe loading site. Also the deck storage permits straight lengths
of pipe to be
easily placed on board.
Fig. 2 is a cross-section showing the optional weather protection 12 and side
retaining system. The barge 10 is of standard construction details.
Fig. 3 shows the stacking hexagonal pattern in cross-section of the pipes 18.
The
pipes 18 are formed in clusters of seven pipes, with interspersed individual
pipes. The
pipes 18 are arranged side by side with a central pipe surrounded by six outer
pipes. Each
of the outer pipes makes linear contact with each of two adjacent outer pipes
and the
central pipe. Linear contact, that is, contact along a line parallel to the
central axis of the
pipe, distributes the loading of the stack of pipes evenly along the pipes.
The pattern is
repetitive in that while the overall system remains hexagonal clusters of
seven pipes 20
and clusters of two pipes 14,16 form sub-patterns at the ends of the pipe
straight sections.
These are the end manifolds 20,14 and 16. The type A and B pipes 14, 16 simply
connect
back onto themselves with a pipe tube with a bend radius of one or more
diameters. The
group of seven pipes is connected to another group of seven by means of the
central pipe,
which is extended and turned through 180 degrees with a bend radius of
approximately
two or more diameters. In theory it is possible to interconnect every pipe
together but this
would be unwise since any leakage would involve the entire cargo. Typically
there will
likely be twenty or more separate cells. Also it is possible to prefabricate
the group of
seven pipes and lift them into position as a single unit rather than welding
the hemi-
spherical manifolds in place after placement of the pipes. At this point it
can be seen that
approximately 33% of the pipes are continuously inspectable by pig.
Fig. 4 shows an enlarged end view of the manifold for the group of seven pipe
bundle. The manifold connects each of the seven pipes into fluid communication
with a
connector pipe. The pipes on the outside reduce or cone to a smaller diameter
22. This
coning or diameter reduction may take place over a short or long distance
depending on
the motions of the barge or ship. When the pitching motion of the ship or
barge is
expected to be small then for drainage purposes the coning distance may be
fairly large in
order to encourage natural drainage of fluids into the hemispherical manifold
20 at the
ends. A feature of the coning is that it permits the pipes to be manifolded
and field welds

CA 02283008 1999-09-22
to be made without interfering with the close hexagonal packing of the pipes.
The central
pipe of the cluster of seven 24 is not coned or reduced in diameter.
Fig.5 is a plan cross-sectional view through the center of Fig.4. At the ends
of the
cones 22 and the central pipe, 24 a flat circular cover plate 28 with holes to
match the
5 cone and central pipe diameters is welded on to the pipe cluster. The hemi-
spherical
containment shel120 is welded to the cover plate with a circular full-strength
weld. The
hemisphere can be welded to the cover plate 28 either before or after it has
been welded
to the seven pipes. Also the hemisphere may or may not contain internal
strengthening
diaphragms to help reduce the shell plate thickness. The transition piece 36
between he
central pipe and the external connecting pipe 26 is a pipe of the same
diameter as the
central pipe except that it has holes in it's wall to allow the gas to
communicate between
the various chambers. This pipe simply serves as a guidance mechanism for the
pig as it
moves from one cluster to another in the central pipe.
Fig.6 shows the pipes as they might appear in an ocean going ship 18. Only a
few
of the pipes are shown and in reality the ship would be full virtually to the
top. The ship
30 is different from other ships in that it does not possess transverse
bulkheads.
Otherwise it is similar to a double-hulled tanker.
Fig 7 shows a detail of the pipes 18 as they might appear in the area of the
transverse watertight seal 32. While the water head design pressure could be
as high as 30
meters the actual force on the individual sealing components is quite low due
to the small
distance that each seal has to span. There are many materials ranging from
silicone to
epoxy that are more than capable of carrying the design head of water. This
innovative
feature allows the pipe to essentially lie the full length of the ships
without having to
penetrate a transverse watertight barrier. This greatly reduces the expense
and complexity
of the total design.
The pipes may be connected in groups of three (triangular pattern), but this
complicates the design and is not preferred. In such an instance, to allow
cleaning of one
third of the pipes, the location of the connector pipe must be offset over one
of the pipes,
or a curved central connector that, inside the manifold, is curved to connect
to one of the
pipes in the cluster of three.

CA 02283008 1999-09-22
6
The invention has now been described with reference to the preferred
embodiments. Substitution of parts and other modifications will now be
apparent to
persons of ordinary skill in the art. In particular, the transport system of
this invention
may be used to transport compressed gasses other than natural gas.
Accordingly, the
invention is not intended to be limited except as provided by the appended
claim.
Features of the invention thus include, in its various aspects: a barge having
a
deck or a ship having internal storage; a compressed gas storage system placed
on top of
the barge deck or in the internal holds of a ship, a plurality of straight
lengths of small
diameter pipe stacked in a hexagonal pattern; a unique manifolding end capping
system
that connects the smaller pipes and unifies groups of approximately seven
(typically) and
approximately two (typically) in such a fashion as to not interfere with the
hexagonal
stacking pattern of the small diameter pipes; and a unique method of providing
a
transverse water tight system when the CNG storage is within the holds of a
ship.

Representative Drawing