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Description  |
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BACKGROUND OF THE INVENTION
This invention is directed to an open sea skimming barge for the removal of
crude oil, refined hydrocarbon product or other floating pollutant slicks
from water surfaces, particularly those slicks caused by accidents while
handling, transporting, processing, controlling, producing or exploring
for hydrocarbons.
For many years, crude oil and refined hydrocarbon product spillages at sea
have been a problem. The environmental damage and cleanup costs of large
spills can reach millions of dollars, which along with damaging publicity
present a serious problem for the industries involved. As more crude oil
and refined hydrocarbon products are being transported over longer
distances by larger tankers, and with the increases in offshore
hydrocarbon exploration and production, the problem of dealing with
spillages is likely to increase.
Since crude oil and refined hydrocarbon product spillages are likely to
continue at an ever increasing rate, a method and apparatus are needed for
reliably removing the spillages as rapidly as possible from the surface of
the water in open seas, or large bays, lakes and rivers.
Slicks in the open sea vary considerably in their characteristics depending
upon the type of crude oil or refined hydrocarbon product spilled, the
weather, size of the spillage and the condition of the sea. The slick
thickness may vary on the surface of the sea and be considered as having a
portion extending below the surface of the sea due to the continual
degradation of the slick by the elements and natural evaporation of the
hydrocarbons.
When compared with the problems of recovering spillages in quiet, calm
seas, bays, harbors or rivers, the recovery of spillages in the open sea,
particularly under adverse weather conditions, is clearly more difficult.
Open sea spillage recovery requires equipment which must be
self-contained, capable of maintaining its station over long periods of
time, and capable of operating in adverse weather conditions, such as in
seas of eight feet or more. Frequently in the past, many types of spillage
recovery equipment have only been effective in relatively calm conditions
and were intended for short term operation.
To date, many types of methods and apparatus have been used in attempts to
deal with spillages.
Detergents and other chemical treatments of slicks have been, and continue
to be utilized, but each has limitations and inherent hazards which can be
as undesirable as the slicks themselves.
Early attempts were usually directed to dealing with spillages of oil in
flowing streams. Typical apparatus comprised collection reservoirs or
rotating drum type pumps, such as shown in U.S. Pat. Nos. 48,411; 54,014
and 95,089.
Prior spillage removal equipment employing endless belt transports, such as
those described in U.S. Pat. Nos. 3,314,540 and 3,314,545, are considered
by their design to have a limited capacity to collect floatage of both
solid and liquid forms of the spillage. More particularly, some prior
constructions depend on the adherence of floatage to the belt transport to
recover solid and liquid floating material of the spillage. Others provide
structures that push the spillage to recover the same, and still others
require pumps to enhance the collection of floatage, such as the belt
transport sold by Marco Pollution Control, Seattle, Wash. Yet others tend
at least to partially bulldoze the spillage being recovered, which
increases the likelihood that some spillage will be pushed to the side and
hence not collected.
Another prior skimming type spillage recovery equipment utilizes a
submerged forward lip or ledge and processes all the inflow, whether
floatage to be removed or the liquid spillage being skimmed, which is
above the shelf edge. This type of recovery equipment generally takes in
the floatage and liquid spillage which is above the shelf edge, and hence
leaves floatage and liquid spillage uncollected where there is a
considerable depth thereof. This type of arrangement is illustrated in
U.S. Pat. Nos. 3,690,464; 3,875,062 and 3,823,828. This skimming equipment
illustrated utilizes the forward velocity of the vessel and the pumping or
suction action of either the vessel's propulsion means or a separate
pumping means to help enhance the flow of spillage over the submerged
forward lip. Wave action will affect this type of skimming equipment since
heavy seas will cause the excessive inflow of water with the spillage
since the control of the depth of the forward lip below the surface of the
water is difficult. With the excessive inflow of water with the spillage,
it will also become more difficult to subsequently separate the spillage
therefrom, thereby requiring other types of separation equipment or much
larger on-board holding tanks for the excessive water and spillage.
Yet another prior skimming type spillage recovery equipment utilizes a
downwardly inclined member having a horizontal slot or opening at the
lower end thereof to force the slick downwardly during the passage of the
inclined member thereover and into the slot or opening due to the pressure
differential created by the buoyancy of the slick. The pressure
differential may be increased to ensure the slick will flow into the slot
or opening through the use of pumps to decrease the pressure within the
cavity fed by the slot or opening. Typical examples of this type of
equipment are described in U.S. Pat. Nos. 3,465,882; 3,615,017; 3,715,034;
3,860,519 and 3,966,615 and published U.K. Patent Application No. GB
2,005,554. In this type of skimming equipment the skimmer may be
stationary having a flowing body of water moving thereby, as in U.S. Pat.
No. 3,465,882, may be self-propelled through the water utilizing a reduced
collection tank pressure, as in U.S. Pat. No. 3,615,017, may be
self-propelled utilizing a variable flap to control the slot or opening
width and merely utilize a gravity settling technique in the collection
tank, as in U.S. Pat. No. 3,715,034, or may be self-propelled utilizing a
reduced collection tank pressure and a wave-receiving splash plate on the
bow thereof, as in published U.K. Patent Application No. GB No. 2,005,554.
This type of spillage recovery equipment requires relatively high
velocities downwardly along the inclined member of the spillage relative
to the inclined member, i.e., for example, five to ten knots, for most
efficient operation and also has a tendency to sidewardly deflect a
portion of the spillage, even with the addition of vertical extensions
along the inclined member to prevent the same. As with the submerged
forward lip type skimming equipment, this type of equipment suffers
performance degradation in heavy seas since it is difficult to control the
height of the inclined member with respect to the wave height. Also, since
in open sea skimming operations high forward velocities are required to
maintain the high velocities of the spillage downwardly along the inclined
member with respect to the inclined member, sideward deflection of the
slick, splashing of the slick over the bow of the vessel, and large bow
waves created by pushing and churning of the spillage, even in calm seas
let along heavy seas, are problems.
Still another type of spillage recovery equipment utilizes a rotating
downwardly inclined endless belt to force the slick downwardly during the
passage of the belt thereover and into a collection tank due to the
pressure differential created by the buoyancy of the slick as it is
depressed. Such equipment is illustrated in U.S. Pat. Nos. 3,314,540;
3,804,251; and 3,812,968. While not necessarily requiring high forward
velocities for skimming operations, such velocities can be artificially
created by increasing the rotational speed of the belts. For open sea
skimming operations of this type of equipment may require the use of many
rotating endless belt assemblies, may have problems operating in heavy
seas due to the inability to compensate for wave height variation thereby
having waves break over the vessel on which the equipment is installed,
and may sidewardly deflect portions of the slick during operations thereby
lowering the effective skimming efficiency of the device.
Other types of recovery equipment utilize a combination of slick separation
techniques in order to remove as much water from the spillage in order to
reduce handling and storage problems on board the equipment. One such
device having an initial submerged forward lip to skim the slick, a
plurality of rotating drums to further separate the water from the slick
and a gravity settling processing tank to further separate the water from
the slick is illustrated in U.S. Pat. No. 3,700,107. Another such device
having an initial suction type skimming device, a further gravity settling
tank for a secondary water and slick separation means and finally a
centrifugal type separating means is illustrated in U.S. Pat. No.
3,957,646.
SUMMARY OF THE INVENTION
The open sea skimming barge of the present invention is self-contained,
capable of maintaining its station over extended periods of time, capable
of operating in adverse weather conditions and utilizes a multiplicity of
separation techniques to ensure the most efficient recovery of open sea
spillages. The open sea skimming barge of the present invention utilizes a
unique spillage suction tunnel having an integral variable flap therein
for initial separation of spillage into a collection tank, a secondary
recovery means for further separation of the spillage in the collection
tank and a tertiary recovery means for the final separation of the
spillage for subsequent storage in holding tanks for offloading. The open
sea skimming barge of the present invention also utilizes spillage
containment booms and storage means therefor.
The present invention and the advantages thereof will be better understood
when taken in conjunction with the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of the open sea skimmer barge of the present
invention.
FIG. 2 is a partial cutaway side view of the open sea skimmer barge of the
present invention showing an oil boom in its stored position and in its
partially deployed position.
FIG. 3 is a partial plan view of the main deck of the open sea skimmer
barge of the present invention.
FIG. 4 is a cross-sectional view along line 4--4 of FIG. 3.
FIG. 5 is a cross-sectional view along line 5--5 of FIG. 3.
FIG. 6 is a cross-sectional view along line 6--6 of FIG. 3.
FIG. 7 is a plan view of the main deck of the open sea skimmer barge of the
present invention.
FIG. 8 is a cross-sectional view along the centerline of the hull on the
open sea skimmer barge of the present invention.
FIG. 9 is a plan view below the main deck of the open sea skimmer barge of
the present invention.
FIG. 10 is a plan view of the tank top level of the open sea skimmer barge
of the present invention.
FIG. 11 is a cross-sectional view along the centerline of the open sea
skimmer barge of the present invention showing the quarters above the main
deck.
FIG. 12 is a plan view along line 12--12 of FIG. 11 including the skimming
control tower.
FIG. 13 is a plan view along line 13--13 of FIG. 11.
FIG. 14 is a plan view along line 14--14 of FIG. 11.
FIG. 15 is a cross-sectional of the secondary oil separation means utilized
on the open sea skimming barge of the present invention.
FIG. 16 is a plan view between decks in the pump room area.
FIG. 17 is a plan view in the pump room area along section line 10--10 of
FIG. 8.
FIG. 18 is a cross-sectional view along section line 18--18 of FIG. 17.
FIG. 19 is a cross-sectional view along section line 19--19 of FIG. 17.
FIG. 20 is a plan view between decks of the machinery room.
FIG. 21 is a plan view of the machinery room along section line 10--10 of
FIG. 8.
FIG. 22 is a cross-sectional view along section line 22--22 of FIG. 21.
FIG. 23 is a cross-sectional view along section line 23--23 of FIG. 21.
FIG. 24 is a cross-sectional view along section line 24--24 of FIG. 21.
FIG. 25 is a plan view of the flap area of the spill suction tunnel of FIG.
8.
FIG. 26 is a cross-sectional view along section line 26--26 of FIG. 25.
FIG. 27 is a cross-sectional view along section line 27--27 of FIG. 25.
FIG. 28 is an enlarged view of area 28 of FIG. 26.
FIG. 29 is an enlarged view of area 29 of FIG. 27.
DESCRIPTION OF THE INVENTION
Referring to FIG. 1, the open sea skimmer barge 10 of the present invention
is shown in its preferred embodiment.
The open sea skimmer barge 10 comprises a hull 12 having a raked bow 14 and
transom stern 16, deck house 18, cranes 20, helideck 22, control tower 24,
skimmer control tower 26, oil booms 28 and life boats 30. Of course,
similar or other hull and superstructure arrangements are acceptable for
use.
The main deck 32 of the hull 12 is constructed having no camber or shear
and the bottom 34 of the hull 12 is constructed having no deadrise. The
hull 12 is further constructed having a bilge radius, having rub rails 36,
having a plurality of suitable fenders 38 thereabout, having retractable
bow thrusters 40 on each side of the raked bow 14, having a transverse
stern thruster 42 (see FIG. 8), having aft ramps 44 for the deployment and
retrieval of the oil booms 28, having oil boom storage supports 46 on the
port and starboard side thereof for the storage of the oil booms 28 when
not in use, and a centerline entry slot 48 (see FIG. 8) at the transom
stern 16 for the entry of the spillage into the hull 12.
The hull 12 further contains various compartments and equipment not shown
in FIG. 1 which will be described hereafter.
Referring to FIG. 2, the open sea skimmer barge 10 is shown in a partial
cutaway view showing one of the aft ramps 44 for the deployment and
retrieval of the oil booms 28. The aft ramps 44 extend along a portion of
aft portion of the hull 12 on either side thereof. The aft ramps 44
provide a surface along which the oil booms 28 may be transported from
their storage position on oil boom storage rails 46 when the booms 28 are
being deployed and retrieved.
The aft ramps 44 terminate along the aft portion of the hull 12 having the
ends 50 of the track ramps 58 being arcuately shaped for the guidance of
the booms 28 with respect to the hull 12 when the open sea skimmer barge
10 is not loaded and at an even keel.
When the booms 28 are deployed, as partially illustrated, to control the
relationship of the boom height with respect to the stern 16 to compensate
for draft changes of the barge 10, the lines securing the boom 28 to the
barge 10 are positioned about a guide roller 52 which is movably retained
in track 54. The guide roller 52 may be vertically adjusted with respect
to the hull 12 by any suitable means secured thereto, such as a pair of
traveling nuts mounted on a powered screw-threaded member secured in
slides.
Referring to FIG. 3, a partial planform view of the main deck of the open
sea skimmer barge 10 is shown.
As shown, each aft ramp 44 supports track ramp 58 and a portion of a track
56 which extends throughout approximately the entire length of the barge
10 being supported by oil boom storage supports 46 where not secured to
the aft ramp 44 having track ramp 58 thereon.
Referring to FIG. 4, the oil boom 28 is shown being supported by the track
56 which is, in turn, supported by track ramp 58 secured to the sidewalls
of an aft ramp 44. As shown, the bottom of the oil boom 28 is provided
with sufficient clearance to permit the free movement of the boom 28 along
each aft ramp 44 without interfering therewith.
Referring to FIG. 5, the oil boom 28 is again shown being supported by the
track 56 which is, in turn, supported by track ramp 58 secured to the
sidewalls of an aft ramp 44.
Referring to FIG. 6, the oil boom 28 is shown being supported by the track
56, which is, in turn, supported by brackets 60 secured to an oil boom
storage support 46. As shown, the bottom of the oil boom 28 is provided
with sufficient clearance to permit the free movement of the boom 28 along
the main deck 32 without interfering therewith during deployment and
retrieval operations.
Referring to FIGS. 1 through 6, it can be easily seen that each oil boom 28
comprises a plurality of boom floats 500 having transverse supports 502
secured thereto having, in turn, rotatable wheels 504 thereon which are
received in the tracks 56, flexible member 506 interconnecting the boom
floats 500, impermeable boom apron 508 secured to the bottom of boom
floats 500 and flexible members 506 and permeable boom apron 510 secured
to the bottom of impermeable boom apron 508 having a suitable line 514
retained within the bottom 512 of the permeable apron 510.
Running through the boom floats 500 is a line 516 suitable for use in
towing operations of the open sea skimmer barge 10.
The first boom float 500' has an attachment means 518 secured thereto which
is, in turn, secured to line 516, impermeable apron 508, permeable apron
510 and line 514. An attachment ring or other suitable means is included
on end 520 of attachment means 518 for a line from a suitable towing means
to be secured thereto.
The line 514 contained within the bottom 512 of the permeable apron 510 is
utilized to weight the aprons 508 and 510 to maintain them in a submerged
state and provide stability to the oil boom 28 during skimming operations.
Referring to FIG. 7, the main deck 32 is shown in planform. As shown, the
main deck 32 has a plurality of pedestal cranes 20 located thereon to
assist in loading and unloading operations of the open sea skimmer barge
10. The stern portion of the main deck 32 includes a plurality of winches
62 to assist in line handling operations and a plurality of washing units
64 for cleaning operations, particularly in the deployment and retrieval
of the oil booms 28. The stern portion of the main deck 32 further
includes the base portion of the skimmer control tower 26, which is
utilized for deck observation, communication, skimmer control and storage
purposes.
Forward of the stern portion of the main deck 32 are a plurality of
observation hatches 66 which allow the observation of the spillage
contained within the forward portion of the oil collection tank
therebelow.
Forward of the observation hatches 66 is a deck storage compartment 68 for
the storage of equipment or stores therein.
On the forward side of the storage compartment 68 are a plurality of filter
belt hatches 70 which allow access to the secondary filter belt separation
means 230 (not shown) located in the oil collection tank 144 therebelow.
Forward of the filter belt hatches 70 are a plurality of sump hatches 72
which allow access to the sump 150 for the secondary oil separation means
230 (not shown) located in the oil collection tank 144.
Forward of the sump hatches 70, located on the port and starboard side of
the open sea skimmer barge 10, are auxiliary boom winches 74 which assist
in the deployment and retrieval of the oil booms 28.
Slightly aft and outboard of the auxiliary boom winches 74 are washing
units 64 which are utilized to clean the oil booms 28 when retrieving and
storing the booms 28 on storage supports 46 (not shown).
Forward of the auxiliary boom winches 74 are a plurality of pump hatches 76
which allow access to the pumping means therebelow, while forward of the
pump hatches 76 and aft of the cranes 20, located amidship of the open sea
skimmer barge 10 on the port side of the barge 10, is an escape scuttle
78, and located on the starboard side is an enclosed stairway 80 leading
to below decks.
Located approximately amidships inboard of the cranes 20 thereat are
tertiary oil separation means 82 which may be of any suitable separation
device, such as a gravity, electrostatic or centrifuge type separation
device.
Located outboard of the tertiary oil separation means 82 are washing means
64 which assist in the cleaning of the oil booms 28 during retrieval and
storing of the booms 28 on storage supports 46 (not shown).
Forward of the cranes 20 and tertiary oil separators 82 is the main deck
portion of the deck house 18. The main deck portion of the deck house 18
includes storage area 84, workshop 86, locker room 88, stairwell 90,
control line trunk 91, storage room 92, laundry 94, pipe chase 96,
equipment removal trunk 98, auxiliary generator 100, air handling
equipment area 102, refrigerated storage 104, dry storage area 106, supply
storage 108, galley 110, supply storage 112, mess 114 and stairwell 116
leading to below decks.
Located in the outboard portion of the main deck portion of the main deck
32 near the bow 14 of the open sea skimmer barge 10 are bow thruster
hatches 118 which allow access to the retractable bow thrusters 40 located
therebelow.
Located on the bow portion of the main deck 32 are oil boom winches 120,
anchor winch 122, chemical dispensant storage tanks 124, jet fuel storage
tanks 126 and anchor 128.
Located at various positions on the port and starboard sides of the main
deck 32 are a plurality of padeyes 130, bitts 132 and cleats 133 (not
shown, see FIG. 1).
Referring to FIG. 8, the hull 12 is shown in cross section.
Starting at the stern 16, the stern portion of the hull 12 includes ballast
tanks 134, spill suction tunnel centerline entry slot 48, entry slot bars
133, and stern thruster compartment 138 having transverse stern thruster
tunnel 140 having, in turn, stern thruster 42 therein. The ballast tanks
134 are utilized for trimming the open sea skimmer barge 10 during
skimming, boom launching and retrieval, and towing operations. The stern
thruster compartment 138 is ventilated and provided with access from the
main deck 32 through hatches (not shown).
Forward of the stern portion of the hull 12, the spill suction tunnel 136
is provided with a plurality of movable flaps 142 which allow spillage and
water to flow into oil collection tank 144 during skimming operations. The
flaps 142 are movable between a closed position where they sealingly
engage the bottom of the oil collection tank 144 forming a portion thereof
to a fully extended position where they abut the bottom 146 of the spill
suction tunnel 136. The flaps 142 may be powered by any suitable means,
such as remotely controlled hydraulic actuators.
Contained within the oil collection tank 144 are a plurality of secondary
oil separation means (not shown) in individual compartments (not shown).
The spill suction tunnel 136 is located below the oil collection tank 144
and located below spill suction tunnel 136 are a plurality of ballast
tanks 148 which are utilized to ballast the open sea skimmer barge 10.
Located forward of oil collection tank 144 are sump 150, induction space
header 152, cofferdam 154, access space 156, pump room 158 having a
plurality of pump power means 160 therein driving a plurality of pumping
means 162 located in spill suction tunnel 136, cofferdam 164 and access
space 166. Located below the spill suction tunnel 136 and forward of
ballast tanks 148 are access space 156, spill compartment 168 and
compartment 170.
Forward of the pump room 158 and cofferdam 164 are recovered oil tanks 172
having cofferdams 174 at the forward end thereof and the outlet 176 of the
spill suction tunnel 136. The outlet 176 of the spill suction tunnel 136
comprises a transition section 178 having flow deflectors 180 therein. The
transition section 178 having flow deflectors 180 therein turns the fluid
flow after discharging from the pumping means 162 in the spill suction
tunnel 136 through approximately a ninety degree (90.degree.) angle so
that the fluid discharge from the outlet 176 of the spill suction tunnel
136 neither produces nor induces any forward or aft thrust on the open sea
skimmer barge 10.
Forward of the cofferdams 174 are potable water storage comparment 182,
machinery space 184 and bow ballast tanks 186 which are utilized for
ballasting of the open sea skimmer barge 10 during maintenance operations.
Referring to FIG. 9, the various compartments of the open sea skimmer barge
10 are shown at a level below the main deck 32 along section line 9--9 of
FIG. 8. The stern portion of the hull 12 includes ballast tanks 134 and
access compartments 188 which provide access to the stern thruster
compartment 138.
Located forward of the stern portion of hull 12 is oil collection tank 144
having a plurality of individual compartments 190 therein, each
compartment 190 having, in turn, a secondary oil separation means (not
shown) located therein. Shown in phantom are the flaps 142 which allow
spillage and water to flow into the oil collection tank 144 during
skimming operations.
Located outboard of the oil collection tank 144 are ballast tanks 134 and
recovered oil tanks 172. It should be remembered that the aft ramps 44
(shown in phantom) which are utilized for the deployment and retrieval of
the oil booms 28 extend into the hull 12 and through portions of ballast
tanks 134 and recovered oil tanks 172 which are outboard of oil collection
tank 144.
As shown, forward of oil collection tank 144 are sump 150 which receives
spillage from the secondary oil separation means, cofferdam 154, pump room
158 having power means 160 therein, and cofferdam 164.
Located forward of cofferdam 164 are primary recovered oil tanks 192,
recovered oil tanks 172, cofferdams 174, potable water tanks 182, fuel oil
tanks 194, machinery space 184, bow thruster compartments 196 and ballast
tanks 186.
Referring to FIG. 10, the various compartments of the open sea skimmer
barge 10 are shown at the tank top level along section line 10--10 of FIG.
8. The stern portion of the hull 12 includes ballast tanks 134, access
compartments 188 which provide access to stern thruster compartment 138.
Located forward of the stern portion of the hull 12 are ballast tanks 134,
ballast tanks 198, and recovered oil tanks 172. As shown, the aft ramps 44
extend through portions of ballast tanks 134 and recovered oil tanks 172.
Continuing forward amidships extend access space 156, spill compartment 168
and compartment 160, while located outboard thereof are induction sumps
200 having induction pumping means (not shown) therein to re | | |
