Note: Descriptions are shown in the official language in which they were submitted.
CA 02636100 2008-06-25
INTERMODAL SHIPPING CONTAINER FOR TRANSPORTING
COMPRESSED GAS
BACKGROUND
Field of the Invention
The present invention relates to an apparatus and method for
transporting compressed gas. Specifically, embodiments of the invention relate
to intermodal containers for transporting compressed gas within pressure
vessels and methods for the manufacture and use thereof.
Description of the Related Art
Gases and similar materials require specialized pressurized containers
for transportation. Natural gas and similar materials are often mined at
locations that are remote from refineries and storage facilities, as well as
the
end users of the materials. Large volumes of pressurized gas are transported
from field to market using multiple forms of transportation.
Pipelines are one traditional form of transportation. However, pipelines
are expensive and time consuming to install over significant distances.
Transportation of gas via pipelines raises political issues relating to the
construction and control of the pipeline. Pipelines often pose regulatory and
environmental challenges as well. Due to these challenges, the costs of
creating
and utilizing a pipeline often make them infeasible as solutions in many
situations.
Pressure vessels are another way to transport gas from the field to
market. Pressure vessels come in many forms and may be built especially for
use with gases stored at very high pressure. Moving compressed gas in
pressure vessels over long distances typically requires multiple modes of
transportation. The compressed gas within the pressure vessels must be
1
CA 02636100 2008-06-25
transferred from one mode of transportation to another along the route to the
target destination. At each transfer point along the route, the gas must be
emptied from one set of pressure vessels and used to fill another set of
pressure
vessels for the next leg of the journey. For example, a cargo ship having a
set of
pressure vessels is used to transport compressed gas from its country of
origin
to a destination country by sea. When the ship arrives at the destination
country, the compressed gas is transferred from pressure vessels aboard the
cargo ship to pressure vessels aboard a train or truck (i.e., a tube trailer)
or into
a pipeline for transport deeper into the destination country. Alternatively,
the
pressure vessels may be physically transferred one by one from the ship to
other forms of transportation such as the train or truck. Both of these
transfer
methods are time consuming and require specialized equipment for pumping
the materials in the vessels or transferring individual pressure vessels. This
increases the cost of shipping the materials in the pressure vessels.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are illustrated by way of example and not
by way of limitation in the figures of the accompanying drawings in which like
references indicate similar elements. It should be noted that different
references to "an" or "one" embodiment in this disclosure are not necessarily
to
the same embodiment, and such references mean at least one.
Figure 1 is a diagram of one embodiment of an intermodal
transportation unit.
Figure 2A is a diagram of one embodiment of the intermodal
transportation unit with a manifold and access panel.
Figure 2B is a diagram of one embodiment of the intermodal
transportation unit without doors and without a manifold to show the rack
structure.
Figure 3 is a diagram of one embodiment of a pressure vessel.
2
CA 02636100 2008-06-25
Figure 4 is a flowchart of one embodiment of a process for constructing
an intermodal transportation unit.
Figure 5 is a flowchart of one embodiment of a process for transporting
a material using an intermodal transportation unit.
DETAILED DESCRIPTION
In the following description, for the purpose of explanation, numerous
specific details are set forth to provide a thorough understanding of the
various
embodiments. It will be apparent to one of ordinary skill in the art that the
embodiments may be practiced without some of these specific details. In other
instances, certain structures and devices are omitted or simplified to avoid
obscuring the details of the various embodiments.
The following description and the accompanying drawings provide
examples for the purposes of illustration. However, these examples should not
be construed in a limiting sense as they are not intended to provide an
exhaustive list of all possible implementations.
Figure 1 is a diagram of one embodiment of an intermodal
transportation unit 100. The intermodal transportation unit 100 may include an
exterior housing 119, such as a 688 dry van container. In one embodiment, the
exterior housing 119 may be cuboid in shape, such as a box or similar shape.
In
other embodiments, the exterior housing 119 may have other geometric shapes
or irregular shapes. In one example embodiment, the external housing 119,
such as the 688 dry van container may be approximately twenty or forty feet in
length (dependent on model), eight and a half feet in height and eight feet
wide. The intermodal transportation unit 100 may have any dimensions
suitable for its purpose. The intermodal transportation unit 100 may be sized
to fit specific modes of transport such as truck trailers, train cars, ship
holding
areas and similar modes of transportation. In another embodiment, the
3
CA 02636100 2008-06-25
intermodal transportation unit 100, may be designed to be used with multiple
modes of transport meeting the restrictions of each mode.
The external housing 119 may include a frame 103 and a set of sidewalls
105. A set as used herein may refer to any number of items including one item.
The frame 103 may be made of a high strength metal such as steel, alloys
thereof, titanium, iron or similar materials. The side panels 105 may be
formed
from metals, plastics or other similar materials. In one embodiment, the frame
103 and side panels 105 may be made from non-combustible or flame retardant
materials to protect the contents from fire. The external housing 119 also
serves
to protect the contents from theft, weather, impact, or similar hazards and
masks the identity of the contents and provides similar benefits.
In one embodiment, the side panels 105 may be removeably attached to
the frame 103 or fixed to the frame 103 by welding, riveting or similar
attachment mechanisms. In one embodiment, the frame 103 and sidewalls 105
may form a complete enclosure. This enclosure may be water tight, air tight,
weather proofed or similarly sealed. Extra panels may also be present in the
sidewalls including the ceiling and floor panels to protect the contents from
heat, cold, forced entry, impact or similar conditions and events.
In one embodiment, the external housing 119 may reduce the effects of a
nearby heat source such as a fire. The intermodal transportation unit 100 has
been tested by being exposed to a pan fire test conducted by the Office of
Hazardous Material Technology. In the test, the pan holds 150 gallons and is
12 foot by 24 foot in size. 150 gallons of Jet A fuel are burned in the pan
over a
period of thirty minutes. A pressure vessel exposed directly to this heat
source
reached a peak temperature of 1161 degrees Fahrenheit. A pressure vessel on a
conventional truck trailer reached a peak temperature of 1005 degrees
Fahrenheit when exposed to the same conditions. However, a pressure vessel
in the intermodal transportation unit 100 exposed to the same conditions
maintained a temperature below 225 degrees Fahrenheit for the full thirty
4
CA 02636100 2008-06-25
minutes. These tests provide an example of the fire protection attributes of
an
intermodal transportation unit 100 containing a set of pressure vessels. In
other embodiments, similar fire protection is provided for other types of
objects
that may be placed within the intermodal transportation unit 100.
In one embodiment, the external housing 119 may include a set of front
101 and rear doors 107. The doors 101, 107 may be removeable side panels,
hinged doors, sliding doors or similar types of doors or access panels. In
another embodiment, other side panels may be configured as doors or access
panels. In a further embodiment, only a single set of doors may be present to
allow access to the pressure vessels 111 within the exterior housing 119.
Doors
and access panels may have locking mechanisms or similar mechanisms to
secure the internal components of the unit.
Figure 2A is a diagram of one embodiment of an end view of an
intermodal transportation unit showing a set of doors with an access panel.
The doors 107 open and close to provide access to the contents of the
intermodal transportation unit 100. In one embodiment, the doors 107 may
include a smaller access panel 257. This panel 257 may be connected by hinge,
by slide mechanism or similar attachment mechanism that allows the access
panel to be opened. The access panel 257 may be used to gain access or limited
access to the interior compartment of the intermodal transportation unit 100
if
the doors are closed.
In one example embodiment, the access panel 257 may be used to
connect a set of pressure vessels and a manifold 251 connected to those
pressure vessels to an external pump to load or unload the contents of the
pressure vessels. The pump may be connected to the manifold 251 through the
port 255 created by the open access panel 257 through a hose 253 or similar
mechanism. This increases the ease in which the contents of the intermodal
transportation unit 100 may be loaded and unloaded. In one example use, the
access panel 257 may be used to connect the pressure vessels to a pumping
CA 02636100 2008-06-25
system on a transport such as a ship. Each pressure vessel may be individually
accessed by a pumping system or a central valve may be present in the
manifold to allow simultaneous access to the pressure vessels.
Returning to a discussion of Figure 1, in one embodiment, the
intermodal transportation unit 100 may include a rack to hold a set of
pressure
vessels 111. The rack may include a set of stands 109A, 109B each supporting a
set of crossbars. The stands 109A, 109B may be independent of one another or
may be connected to one another for support. Figure 2B is a diagram showing
one embodiment of a configuration of the rack 200. In one example
embodiment, the rack 200 may include four crossbars 201 creating three rows
for storing pressure vessels 111. Any number of crossbars 201 may be utilized
dependent on the size of the intermodal transportation unit 100 and the size
of
the pressure vessels 111. Also, additional vertical bars or stands may be
utilized in the rack to provide additional support to the pressure vessels
111.
For example, a set of stress rods 211 may reinforce the stand 109. Any number
of stress rods 211 may support the rack 200. Any number of columns of
pressure vessels may be defined by the rack 200. The stand 109B, crossbars 201
and stress rods 211 may be formed from metals such as steel or aluminum, or
other similar materials with sufficient material strength to support the
weight
of a set of pressure vessels 111. For example, the stress rods 211 may be 7/8
inch diameter steel rods.
Crossbars 201, stress rods 211 and stands 109A, 109B may be welded
together, interlocking or similarly connected. In one embodiment, the
connections may be reinforced by bolts through the joints between the
crossbars 201, stress rods 211 and stands 109A, 109B. In one embodiment, the
holes may be drilled and the bolts 213 inserted after the rack has been loaded
and compressed by a load mechanism 215 or preloaded to simulate the weight
of full pressure vessels. For example, a bottom row of the rack 200 may be
loaded with pressure vessels and a crossbar placed over them. The next row is
loaded on a crossbar placed over the pressure vessels. This process may repeat
6
CA 02636100 2008-06-25
until all the rows are loaded. The load mechanism 215 may exert pressure on a
top crossbar to settle the pressure vessels into place and exert a compressing
force to hold them in place. The load mechanism 215 holds or clamps the rack
200 and the pressure vessels on the rack 200 in a compressed or secure
position.
The holes for the bolts may then be drilled and the bolts 213 inserted to hold
the structure in place. The load mechanism 215 may be any tightening or load
exerting mechanism including a clamping mechanism, spring mechanism,
tightening bolt or similar loading mechanisms.
In one embodiment, the reinforcement provided by the stress rods 211
may improve the strength of the intermodal transportation unit 100 in the
event of a rollover. The combination of the crossbars 201 and stress rods 211
maintain the shape of the rack 200 and protect the pressure vessels 111. This
structure also assists in holding the pressure vessels 111 in place when
placed
under the stress of sharp turns or impacts.
In one embodiment, each crossbar 201 may have a set of positioning
members 203A, 203B. The positioning members 203A, 203B may have a shape
complimentary to the exterior cross-sectional shape of the pressure vessels
111
to secure the pressure vessels 111 during transport. The positioning members
203A, 203B may be attached to the crossbars 201 by welding, adhesion, riveting
or similar attachment mechanisms. In another embodiment, the positioning
members 203A, 203B may be integrally formed with the crossbars 201. The
positioning members 203A, 203B of each crossbar 201 define the placement of
the pressure vessels 111 within the rack 200. Any number of pressure vessels
111 may be accommodated by the rack 200 dependent on the size of the
intermodal transportation unit 100, size of the pressure vessels 111 and
spacing
of positioning members 203A, 203B.
In one embodiment, a set of friction members 205A, 205B may be
attached to the positioning members 203A, 203B to reduce the longitudinal
movement of the pressure vessels 111 during transport. The friction members
7
CA 02636100 2008-06-25
205A, 205B may be a natural material such as rubber, a synthetic material or
any material capable of providing sufficient surface friction to prevent or
minimize the longitudinal movement of the pressure vessels. In one
embodiment, the friction members 205A, 205B may have elastomeric properties
to accommodate expansion of the tubes during filling or due to changes in
temperature. The friction members 205A, 205B may be welded, adhered, form
fit or similarly attached to the positioning members 203A, 203B. The friction
members 205A, 205B may be friction enhancing cushions and provide padding
to cushion the pressure vessels 111 during transport. In one embodiment the
friction members may be made of tire rubber.
Returning to the discussion of Figure 1, the rack stands 109A, 109B may
be positioned adjacent to each end of the pressure vessels 111 to provide a
level
support for each pressure vessel 111. In one example embodiment, two stands
109A, 109B are present in the intermodal transportation unit 100. In another
embodiment, any number of stands may be utilized along the length of the
pressure vessels 111 to provide support during transport. In one embodiment,
the rack stands 109A, 109B provide support and secure the pressure vessels 111
along a body portion of the pressure vessels and do not support the pressure
vessels 111 at the neck portion. Supporting the pressure vessels 111 in the
neck
portion may cause a higher level of wear and limit the lifespan of the
pressure
vessels.
Figure 3 is a diagram of one embodiment of a pressure vessel 111. The
pressure vessel 111 may have a body portion 301 and a neck portion 303. The
neck portion 303 defines an opening for filling and empting the vessel 111.
The
pressure vessel 111 may include an inner core 305. The inner core 305 may be
composed of steel, steel alloys, carbon steel, monel, inconel, hastelloy,
titanium
and similar materials. The inner core 305 may be encased in a composite
reinforcement layer 307. The composite reinforcement layer 307 may be an
isopolyester resin matrix, polyester, aramid or other fiber material or
similar
composite materials. A third layer of woven reinforcement tape 309 may also
8
CA 02636100 2008-06-25
be placed over the composite layer 307. In another embodiment, the
reinforcement lay 309 may be omitted.
In one embodiment, the inner core 303, composite layer 307 or woven
tape layer 309 may be formed with a thickened wall or region in at least one
segment along the length of the pressure vessel 111. The thickened wall may
form an annular protrusion 311 from the surface of the pressure vessel 111. In
another embodiment, the protrusion 111 may have other shapes such as a set of
bumps in an annular pattern. Any number of thickened walls may be formed
in the pressure vessel 111. The thickened walls may also be positioned at any
point along the length of the pressure vessel.
The pressure vessel 311 may have a tube or other elongated shape. The
pressure vessel 311 may have any dimensions and shape suitable for providing
sufficient strength for storing pressurized materials and for ease of
transportation. The pressure vessel 111 may have a single opening in the neck
portion. The opening may be fitted with a stop or valve to control the release
and fill of the vessel 111. In another embodiment, the pressure vessel 11 may
have a neck and opening at each end. Each opening may be fitted with a stop
or valve to control the release and fill of the vessel 111.
Returning to the discussion of Figure 1, the pressure vessels 111 are
restricted in longitudinal movement with relation to the rack by a combination
of the friction members attached to the positioning members and the thickened
wall forming protruding sections 113A, 113B on each pressure vessel 111. The
protruding sections 113A, 113B may be positioned on either side of the
positioning members and friction members to inhibit longitudinal movement
in either direction. The protruding sections 113A, 113B may both be adjacent
to
the positioning members of the stand 109A in any combination of positions
including both being inside of the positioning members, both being outside
and one being outside and the other inside. Additional combinations may be
9
CA 02636100 2008-06-25
formed if additional protrusions, for example one on either side of a
positioning member, or additional stands are present.
In one embodiment, the rack stands 109A, 109B may be secured to the
exterior housing 119 through a bracket, pin, riveting, welding, or other stop
or
attachment mechanism. In one example embodiment, the rack stands 109A,
109B may be secured to the exterior housing 119 through a z-bar 115 and screw
or rivet 117. The z-bar 115 may prevent the longitudinal movement of the rack
during transportation in relation to the exterior housing. The attachment
mechanism may be placed at the base of each stand 109A, 109B. In other
embodiments, attachment mechanisms may secure the stands 109A, 109B along
other portions of the rack such as the top of the stands or the sides of the
stands. Any number of attachment mechanisms may be used to secure the
rack. In one example embodiment, a set of bolts 121 may extend through the
external housing 119 into the stands 109A, 109B. The bolts 121 may be inserted
after loading and clamping the rack 200 with a load mechanism or prior to
loading and clamping the rack 200. Holes may be drilled through the external
housing and into the stands 109A, 109B to allow the bolts 121 to be inserted.
In
one example embodiment, six inch washers may be placed between the
external housing 119 and the head of the bolt 121.
In one embodiment, the intermodal transportation unit 100 may include
a set of strong points for use in moving the unit. These strong points, e.g.
corner castings, may be used by cranes or lifting machines for moving the unit
without damage to the unit and its contents. These strong points may be
positioned at any point on the intermodal transportation unit 100. The strong
points may be fitted with hooks, loops or similar mechanism to facilitate
lifting
and moving the unit 100.
Figure 4 is a flowchart of one embodiment of a process for constructing
an intermodal transportation unit. In one embodiment, a portion of the
exterior housing may be assembled such as the floor and sides or the entire
CA 02636100 2008-06-25
exterior housing (block 401). A rack may then be installed into the exterior
housing (block 403). The rack may be installed as a single unit or may be
installed in sections such as stand by stand and crossbar by crossbar. The
rack
may then be secured to the exterior housing (block 405). The rack may be
secured by any type of attachment mechanism. For example, a set of z-bars or
bolts may be used to attach the rack stands to the exterior housing.
In one embodiment, the pressure vessels may then be placed in the rack
(block 407). The positioning members may be adjustable or the crossbars and
stress rods in the rack may be adjustable to facilitate the placement of the
pressure vessels in the rack. In another embodiment, the pressure vessels may
be placed in the rack prior to its installation into the exterior housing.
After
each pressure vessel is placed in the rack or after all of the pressure
vessels
have been placed in the rack, the pressure vessels may be secured within the
rack (block 409). The pressure vessels may be secured by tightening the
positioning mechanisms or crossbars or through similar mechanisms.
In one embodiment, after the pressure vessels are secured within the
rack they may be enclosed by the exterior housing (block 411). The exterior
housing may be completed by adding missing portions such as the top or side.
In another embodiment, the rack may be loaded through the front or rear doors
or other access panel. The front or rear doors may be closed or the access
panel
reattached to complete the enclosure.
Figure 5 is a flowchart of one embodiment of a process for use of the
intermodal transportation unit. In one embodiment, after the intermodal
transportation unit has been constructed it may be loaded unto a first form of
transportation, such a truck, train or ship (block 501). Any type of transport
vehicle may be used. The unit may be moved by a lift, crane or similar
machinery. The machinery used for the movement of the unit may be general
use moving machinery instead of machinery specialized for the movement of
pressure vessels.
11
CA 02636100 2008-06-25
After the intermodal transportation unit has been properly loaded onto
the first vehicle, the pressure vessels may be filled with a material to be
shipped (block 503). All vessels may carry the same materials or different
vessels may carry different materials or amounts of materials. The pressure
vessels may be filled one by one or several or all of the vessels may be filed
at
the same time. The vessels may be filled through an external system that
connects to the neck portion and the stops or valves attached to the vessels.
The external filling system may access the pressure vessels through a front or
rear door or other access panel of the unit. In another embodiment, the
vessels
may be filled prior to being loaded into the intermodal transportation unit.
In
a further embodiment, a portion of the filling system may be integrated or
attached to the intermodal transportation unit.
After the vessels are filled or at least a portion of the vessels are at least
partially filled, the intermodal transportation unit may be closed to
completely
enclose the pressure vessels (block 505). The unit may be closed by closing
and
securing doors or replacing and securing an access panel or through a similar
mechanism.
The intermodal transportation unit may be transported to an
intermediate location or a first destination by the first mode of
transportation
(block 507). At the first location, a determination is made as to whether a
delivery of materials is scheduled (block 509). If a delivery is scheduled,
then
the intermodal transportation unit is opened and the appropriate amount of
materials, either a portion or the whole, are emptied from the appropriate
pressure vessel (block 511).
After delivery, or if no delivery is scheduled at the location, then it is
determined if the final destination has been reached (block 513). If the final
destination has been reached then the intermodal transportation unit may be
taken to the start of a new delivery route (block 515). This may include
transferring the unit to a new form of transportation or the start of the new
12
CA 02636100 2014-12-05
route may be the current location, the final destination. The new form of
transportation may be a truck, train, ship or similar vehicle. The new form of
transportation may be of the same type but a different vehicle. For example,
the intermodal transportation unit may be moved from one truck to another or
from one ship to another. At the start of the new route, the process may
continue by filling the vessels (block 503).
If the final destination has not been reached, then a determination may
be made to transfer the intermodal transportation unit to a new form of
transportation (block 517). If the unit is not to be transferred, then the
unit is
closed (block 505) and transported to the next location (block 507). This
process
may continue until the destination is reached.
If the unit is to be transferred, then the unit is closed (block 519) and
then transferred to the new form of transportation (block 521). The intermodal
transportation unit may be moved by standard lifting and moving equipment.
The new form of transport may be any type of vehicle including the same type
of vehicle from which it is transferred. After transfer, the new form of
transportation may take the unit to the next location (block 507). This
process
may continue until the destination is reached.
In the foregoing specification, the embodiments of the invention have
been described with reference to specific embodiments thereof. The scope
of the claims should not be limited by the preferred embodiments set forth
in the examples but should be given the broadest interpretation consistent
with the description as a whole.
13
