Patent Application
20110265449
The present invention relates to control of emissions from Ocean Going Vessels (OGVs) at berth or anchored in port and in particular to the capture of exhaust gases from the OGVs to allow subsequent processing.
OGVs at berth or anchored in port are a significant source of air pollution from the exhaust gases of their auxiliary power sources. The OGVs have auxiliary diesel engines and auxiliary boilers which normally remain in operation while the OGV is at berth or anchored. The auxiliary engines drive generators which provide power for ballast and other pumps, onboard motors, shipboard lighting and air conditioning, communications equipment, and other housekeeping functions. The auxiliary boilers are used to keep the bunker fuel used to feed the main engines warm. If allowed to cool, this fuel becomes so viscous it is difficult or impossible to pump. Heat from the boilers is also used for other shipboard functions.
The boilers and auxiliary engines are a source of nitrogen dioxide (NOx), sulfur dioxide (SOx), particulate matter (PM), and volatile organic compounds (VOCs), all of which are air pollutants. Left untreated, the OGVs are one of the most significant sources of air pollution in the vicinity of ports throughout the world.
The OGV discharge the exhaust from the auxiliary engines and auxiliary boilers, as well as other less significant pollutant sources such as the galley and incinerators, through exhaust pipes clustered within an exhaust stack which runs from the engine room up through the OGV's decks and continues some distance above the top deck. U.S. Pat. No. 7,258,710 for “Maritime Emissions Control System,” assigned to the assignee of the present invention, describes a maritime emissions control system which may be transported by barge or vessel to an OGV near or within a harbor. The maritime emissions control system uses a bonnet (or umbrella-like device) which is lifted up above the top of the OGV exhaust stack and then lowered over the entire exhaust stack of the OGV and sealing around the exhaust stack perimeter, thereby capturing exhaust otherwise released to the environment. The '710 patent further discloses processing the exhaust flow from the OGV to reduce emissions. The '710 patent is herein incorporated in its entirety by reference.
The top of the stack is usually the highest part (other than antennas) of the OGV. The stack of an OGV is typically 15 to 30 feet on a side and often rectangular, but it can be round or oval or some other shape. The stack side walls are usually vertical or slightly tapered, but sometimes have sharp lips protruding from the side, railings near the top, or other features which depart from smooth sides, and the stacks frequently include air intakes for the engine room and other interior spaces at some point below the stack rim. The individual exhaust pipes exit through a recessed floor located a few feet below the top rim of the stack, and generally extend upward a small distance above the stack.
Unfortunately, there are some difficulties in positioning a bonnet over the OGV stack. The OGV's antennas are often close to the stack, wires are often attached to the rim of stack, the stack may be built into OGV superstructure, appendages reach from the rim of stack, and/or extreme stack dimensions.
Another issue is the difficulty in sealing the bonnet to the stack, which can result in escape of exhaust gas or ingestion of air through a gap between the vessel stack and the inner periphery of the bonnet in which case the bonnet will capture only a portion of the exhaust gas and simultaneously ingest significant volumes of atmospheric air reducing the efficiency of the processing unit. Tension devices intended to effect a seal between the bonnet and stack are difficult at best to implement on a rectangular surface with large flat sides, and bladder type devices are cumbersome and unreliable and require external apparatus such as an air blower or pressure vessel to inflate them. Even if an acceptable seal is achieved with a bonnet, wind forces and wind gusts “pump” the bonnet like a bellows once it is attached, and this action may force exhaust gas out around the perimeter while simultaneously creating over-pressure followed by under-pressure within the bonnet and consequently on the boiler exhaust, which is detrimental to boiler performance and can even cause flame extinguishment in extreme cases.
Another issue is the ingestion of non-exhaust gas flowing from vent pipes in the stack, gaps around each of the exhaust pipes where they exit the stack deck, gaps around the access door to the stack deck, and steam vents. Another issue is the bonnet's size and weight make using it on a barge potentially difficult.
Another issue is the “breathing” or volumetric changes to the inside volume of the bonnet caused by wind eddies and gusts, which often have the effect of forcing exhaust gas out the imperfect seal around the interface between the bonnet and the stack.
Another issue is the difficulty in attaching the bonnet to the stack during high winds because of the large bonnet surface area exposed to the wind. The surface of a bonnet sufficiently large to encompass the typical OGV exhaust stack is 20 to 30 feet on a side, usually square, rectangular, hexagonal, octagonal, or oval. Such a large surface, hanging from a crane or other placement device many tens of feet and often over 100 feet in the air, is frequently subjected to wind forces which cause the bonnet to sway with relatively large excursions, creating the danger of hitting and damaging antennas or other nearby OGV structures. This movement also makes alignment and attachment to the stack difficult if not impossible in windy conditions.
An additional drawback to the bonnet is its weight. Due to the size required to encompass the OGV stack, the bonnet and its actuating and support structure is heavy, requiring a substantial lifting capability for the crane or other placement device.
Yet another drawback is inherent in the large volume enclosed by the bonnet. The interior of the bonnet is the size of a room, so control of the vacuum within this bonnet which is necessary to ensure that gas is drawn out of the pipes rather than impeded from exiting each exhaust pipe, and of ensuring that over pressure will not force exhaust gas back down to the engine room through openings in the stack itself, is very difficult, exacerbated by variable exhaust flows and gusting wind.
Another issue is that known bonnet designs are fairly complex and may prove unreliable. Known bonnet designs include numerous motors, cables, and control devices to furl and unfurl or extend and retract and secure the bonnet to the stack, all of which add complexity, weight, and failure modes, and require that electrical, pneumatic, or hydraulic power be routed to the bonnet. Additionally, a large crane or similar lifting and placement device is required for the bonnet due to its weight and potential wind forces, which adds cost and structure needed to support the crane.
The present invention addresses the above and other needs by providing an exhaust gas capture system for capturing the exhaust gas emitted by auxiliary engines, auxiliary boilers, and other sources on an Ocean Going Vessel (OGV) while at berth or at anchor so that these gases may be carried to an emissions treatment system for removal of air pollutants and/or greenhouse gases. The exhaust gas capture system includes a manifold and a family of parallel-flow ducts for connecting directly to each individual OGV exhaust pipe and carrying parallel exhaust gas flows to the common manifold. The exhaust gas capture system further includes apparatus for connecting the parallel-flow flexible ducts to the OGV exhaust pipes.
In accordance with another aspect of the invention, there is provided a system for capture and removal of the pollutant-laden exhaust gas from the OGV exhaust pipes. Once captured, the exhaust gases are carried to an emissions treatment system on shore, or on a barge, for pollutant removal.
In accordance with yet another aspect of the invention, there are provided couplings to connect each of the parallel exhaust gas collecting ducts to individual OGV exhaust pipes. The couplings serve several functions and may take on any of several forms, employ any of several means of securing each coupling to the pipes, and use any of several means for closing off or sealing the interface between the duct and the exhaust pipe to reduce or eliminate exhaust gas leakage. In accordance with another aspect of the invention, a placement device lifts the manifold and ducts to a position directly above the exhaust pipes so that the parallel ducts may be deployed over the individual OGV exhaust pipes without further manual or mechanical intervention required to extend the ducts to reach the exhaust pipes.
In accordance with another aspect of the invention, a robotic manipulator arm is preferably used to position the parallel ducts for coupling to the exhaust pipes. Alternatively, alignment may be conducted by a technician who has been lifted up above the top of the stack near the exhaust pipe exit by a manlift or other conveyance or by a technician aboard the OGV, and connection of the parallel ducts to the individual exhaust pipes effected either manually or by other means such as a remote controlled actuating device.
In accordance with another aspect of the invention, there is provided a manifold positionable near the top of the OGV exhaust stack. The manifold serves multiple functions, among them: a collection manifold to accept exhaust gas from the parallel-flow flexible ducts and discharge the combined exhaust gas through one common duct to an emissions treatment system; a pressure/vacuum control chamber; an over-pressure and under-vacuum safety relief device; a pneumatic compliance to moderate the effects of transitions in flow rate as engines or boilers come on or off line; and a docking station for the parallel-flow flexible ducts.
In accordance with still another aspect of the invention, there are provided parallel-flow flexible ducts, each of which connect the manifold to an OGV exhaust pipe. The parallel-flow flexible ducts may hang in a loop, be housed in a magazine attached to the manifold, or be on a roll. When not in use, a free end of each parallel flexible duct is secured to a docking station on the manifold. A manually operated or robotic manipulator arm is used to undock the parallel-flow flexible ducts one at a time and position the parallel-flow flexible ducts for coupling to the OGV exhaust pipes. Alternatively, this undocking and moving function may be performed manually. Further, the parallel flexible ducts may simply either hang freely, or be released from the docking station and allowed to drop to a location above the OGV exhaust pipes. Various available motions (degrees of freedom) of the manipulator arm may be employed to perform additional functions both during the act of removing each of the parallel-flow flexible ducts from its docking station, and during actions of positioning and coupling each flexible duct to a corresponding exhaust pipe.
In accordance with yet another aspect of the invention, there are provided automatically actuated valves, couplings and seals for each of the parallel-flow flexible ducts. The action of lifting or undocking each of the parallel-flow flexible ducts may be coupled to a mechanism on the manipulator arm to open or close valves and/or clamps or latches of the parallel-flow flexible ducts. For example, the simultaneous act of gripping (squeezing) a duct lifting handle may perform these or other actions. Similarly, while placing the coupling over the exhaust pipe, the actions of lifting or releasing, as well as the ability of the end effector (the last robotic arm section, which is attached to the last joint on the manipulator arm) to rotate, may be coupled to placement, securing, and/or sealing of the attachment device.
In another aspect of the invention, each coupling device may be utilized to perform several functions, including alignment of each flexible duct with the corresponding exhaust pipe, facilitate flexible duct attachment to, or insertion over or inside the exhaust pipe, and seal or close off the interface between each flexible duct with the corresponding exhaust pipe.
In accordance with another aspect of the invention, there is provided a manipulator arm. The manipulator arm may be a commercially available device which may be modified for use with the exhaust capture system, and it may be robotic or manually operated by a joystick, opening and closing valves, or other control devices. Operation of the manipulator arm may be integrated into a control system which positions the manifold near the OGV stack. Alternatively or additionally, sensors and/or a vision system may be included to locate the individual exhaust pipes to direct the placement of the coupling devices on or over each exhaust pipe. When the manipulator arm is coupled with a vision system, a remote operator is able to place the manifold into the required location and then attach the individual flexible ducts to the exhaust pipes. Alternatively or additionally, infrared and/or acoustic and/or other sensors allowing partial or complete automatic operation, may be included in the exhaust gas capture system.
In accordance with yet another aspect of the invention, there is provided an OGV exhaust gas capture system having advantages over a bonnet including simplicity of design and mechanisms, reliability, small size, low weight, minimal power requirements, the possibility of relatively unskilled or even unattended operation, and low operational and maintenance cost.
In accordance with another aspect of the invention, there is provided an OGV exhaust gas capture system having a connector including a coupling and a stepped cone. The coupling selected from an elastomeric rigid cone with the diameter becoming larger away from the open end which is pushed into the OGV exhaust pipe, and which further includes ribs on the outside of the cone to increase the holding power of the cone inside the OGV exhaust pipe, and an elastomeric coated rigid cone with the diameter becoming larger away from the open end which is pushed into the OGV exhaust pipe, and which further includes ribs on the outside of the cone to increase the holding power of the cone inside the OGV exhaust pipe. The stepwise tapered elastomeric cone includes exterior ridges which will fit into various sizes of OGV exhaust pipe inside diameters.
In accordance with yet another aspect of the invention, there is provided an OGV exhaust gas capture system having a connector including a drape-like assembly which is draped over the outside of the OGV exhaust pipe and which then falls or scoots down the outside of the pipe, pulling the flexible duct into place over the open end of the exhaust pipe. The drape-like assembly includes segmented vertically spaced apart horizontal stringers and attached at either end to a vertical cable. The vertical cables are spread apart by the horizontal stringers and horizontal bars at the bottom of the drape-like assembly, the horizontal bars carrying several spaced apart rollers. A flat plate at the top of the drape-like assembly mates to the flexible duct and has an opening approximately the size of the exhaust pipe bore and an elastomeric gasket to seal against the end of the pipe, and three or more tapered ribs or a tapered cage which centers the flat plate over the opening of the exhaust pipe.
In accordance with yet another aspect of the invention, there is provided an OGV exhaust gas capture system having a manifold serving as a pressure/vacuum control chamber, wherein the volume of the manifold provides mechanical compliance to smooth out pressure excursions which could otherwise occur when flows from the OGV exhaust pipes change. The manifold includes a plenum, pressure sensors, a double acting valve, lightweight manifold couplings, a docking station, and valves. The pressure sensors provide a feedback control signal for a fan, adjusting the fan speed to maintain a slight vacuum within the manifold regardless of exhaust flow. The double acting valve in one end of the manifold providing an over-pressure relief and an under-pressure relief to protect the system and especially the ship systems. The lightweight manifold couplings couple the plurality of flexible ducts connecting the OGV exhaust pipes to the manifold. The docking station may include a hook, bracket, or other mechanical means of hanging the flexible duct; or a magazine or cylindrical chamber into which the flexible duct is collapsed for storage. The valves are provided to adjust and balance the flow from the OGV exhaust pipes.
In accordance with yet another aspect of the invention, there is provided an OGV exhaust gas capture system having a manifold having a hook, a bracket, or other mechanical means of hanging unused flexible ducts, (i.e., flexible ducts not connected to OGV exhaust pipes. Valves are provided to close off the unused flexible ducts to avoid ingesting outside air and thereby increasing the load on an induced draft fan which would require more electricity.
The above and other aspects, features and advantages of the present invention will be more apparent from the following more particular description thereof, presented in conjunction with the following drawings wherein:
Corresponding reference characters indicate corresponding components throughout the several views of the drawings.
The following description is of the best mode presently contemplated for carrying out the invention. This description is not to be taken in a limiting sense, but is made merely for the purpose of describing one or more preferred embodiments of the invention. The scope of the invention should be determined with reference to the claims.
In the following detailed description, the term stack refers to the large structure protruding from the upper part of an Ocean Going Vessel (OGV) and from which exhaust gas may be observed to exit. An alternative term for stack, used by some in the marine field, is funnel. The stack contains or encompasses several individual OGV exhaust pipes. Each of the OGV exhaust pipes connects to one source of exhaust gas such as one auxiliary engine or one auxiliary boiler or the onboard incinerator. The terms vessel and OGV mean one and the same, namely an ocean going vessel used to transport cargo or people, and the terms are used interchangeably. The term hotelling means the OGV is at berth or at anchor with the main engines off. During hotelling, ongoing shipboard activities continue to require electrical, heat, and steam power.
An exhaust capture system 10 according to the present invention is shown in
Commercial OGVs 12 such as container vessels, tankers, passenger, RoRo, and bulk carriers have several OGV exhaust pipes 16. Each of the OGV exhaust pipes 16 receives exhaust gas from one or more source of exhaust gas such as an auxiliary diesel engine, auxiliary boiler, or incinerator. The OGV 12 typically has three or more auxiliary engines of which one or two are operating while the OGV 12 is at berth, and one or more auxiliary boilers of which one is normally operating either continuously or intermittently at berth, except in the case of tankers offloading cargo with onboard steam driven pumps, in which case two or three auxiliary boilers may be operating. There are also minor sources of gaseous discharge from OGV 12 housekeeping activities such as the galley or incinerator, each of which has an exhaust pipe, but these are generally not a significant source of air pollution and the incinerator is not usually used in port. The only exhaust pipes to which this invention would normally be connected are those from the auxiliary boiler(s) and the auxiliary engines.
The OGV 12 main engine exhaust pipe(s) are not addressed by the present invention because the main engines are not operating during the time the OGV 12 is at berth or at anchor except during preparation for departure (main engines are almost always direct coupled, so if the main engine is running the propeller is turning.) The OGV exhaust pipes 16 addressed by the exhaust capture system 10, of which there are typically five or more from auxiliary engines, auxiliary boilers, and other sources, are generally routed through the OGV stack 14 and exit the OGV 12 through passages in a floor within the stack 14, which floor is usually located a few feet below the top of the stack 14. The pipes 16 extend vertically above the floor and above the peak of the exhaust stack 14.
The top end of the OGV exhaust pipes 16 may be vertical, bent toward horizontal, or cut at an angle, and occasionally the OGV exhaust pipes 16 are simply vertical pipes open at the top. However, the tops of the individual OGV exhaust pipes 16 often include a 90 degree bend towards the OGV aft to direct the exhaust gas toward the aft end of the OGV 12. The OGV exhaust pipes 16 are round and the OGV exhaust pipes 16 diameter can vary from about 6 inches for an incinerator to 16 inches or more for a large auxiliary boiler. The OGV exhaust pipes 16 releasing the most pollution generally range from about eight inches to sixteen inches in diameter because incinerator exhaust is not normally an issue and is not an exhaust pipe size to which this invention would generally be required to address.
A side view of the manifold 20, the main duct 18 and the parallel-flow flexible ducts 22 is shown in
Making a connection between the parallel-flow flexible ducts 22 and the OGV exhaust pipes 16 in order to route the exhaust gas to the emissions treatment system 19 requires addressing several factors. Any connection must accommodate six degrees of freedom motion of the OGV 12. The motions of the OGV 12 include translating in three directions and rotating about three axes. Additionally, the slow draft changes due to tide and cargo loading or unloading can lift or lower the OGV 12 as much as 40 feet vertically.
Another consideration is that the main ducting 18 required to carry the exhaust gas to the emissions treatment system 19 is generally too heavy and awkward to be easily handled manually, so some sort of assist is usually required. In addition it is possible, but not desirable, to require that personnel board the vessel and climb up the OGV stack 14 to connect the exhaust capture system 10 to the OGV exhaust pipes 16. The exhaust gas is hot, typically 550 degrees Fahrenheit, so any exhaust collection device must be capable of operating in a high temperature environment. Safety issues are a major concern and if an emergency is declared, all connections to the OGV must be freed within 20 to 30 minutes. All of this is complicated, because currently, modification of the OGV is not allowed.
The exhaust capture system 10 also includes the apparatus for positioning the manifold 20 in the vicinity of the top of the OGV exhaust stack 14, in which the exhaust from all the OGV exhaust pipes 16 is combined for transmission through a main duct 18 to the emissions treatment system 19. The exhaust capture system 10 also includes apparatus to set and maintain flow and pressure in each individual flexible duct as it is attached to an OGV exhaust pipe as well as during subsequent operation so as to preclude significant alteration of preexisting exhaust flows, back pressure, or boiler operation.
The exhaust capture system 10 may include sensors for determining the location of the OGV exhaust pipes 16 and moving the parallel-flow flexible ducts 22 to that location, aligning the parallel-flow flexible ducts 22 to the respective OGV exhaust pipe 16, securing an adequate seal, and providing an attachment to the exhaust pipe 16 sufficient to hold the parallel-flow flexible duct 22 in position. The locating, positioning, and attaching activity may be by direct visual means and a joy stick, by a valve block, or other manual controller, by video and or infrared and or acoustic and or laser or similar means with a remote human operator, or it may be partially or fully automatic with remote human oversight and override capability, or by a combination of these methods.
A method according to the present invention for attaching the parallel-flow flexible ducts 22 of the exhaust capture system 10 to individual OGV exhaust pipes 16 of the OGV 12 are shown in
The flexible ducts 22 are sequentially attached to the OGV exhaust pipes 16 to collect the exhaust gas from the individual OGV exhaust pipes 16. The parallel-flow flexible ducts 22 capture and transport the OGV exhaust gas to the manifold 20 and the exhaust gas is subsequently carried by the main duct 18 to the emissions treatment system 19. The manifold 20 is preferably attached to a placement device such as a hydraulic lift (but may be attached to the duct support boom 24) which is capable of reaching a location proximal to the uppermost termination of the OGV exhaust stack 14. The manifold 20 includes instrumentation and mechanisms which may be used to control flow and/or pressure in various parts of the exhaust capture system 10.
The parallel-flow flexible ducts 22, and the coupling 26 which connects and seals the parallel-flow flexible ducts 22 to the OGV exhaust pipes 16, present a very small profile to the wind. The parallel-flow flexible ducts 22 and the coupling 26 are preferably approximately one foot in diameter as opposed to the 20 feet or more for a bonnet as described in the '710 patent. Since wind force is proportional to area, the force imparted to the parallel-flow flexible ducts 22 and the coupling 26 is 100 to 1000 times less than with a bonnet. The wind force is effectively even smaller, because the drag coefficient of a cylinder is on the order of 1.2 while for a flat surface it is approximately 2. The net result is that the exhaust capture system 10 of the present invention suffers very little force and resulting motion due to wind so is far easier to position over the OGV exhaust pipes 16, and it presents virtually no hazard to nearby antennas or other OGV structures.
Unlike a system using a bonnet, the exhaust capture system 10 has very small internal volume, acting as only a continuation of the OGV exhaust pipe 16 through the parallel-flow flexible duct 22 to the manifold 20. Thus, back pressures may be accurately controlled and maintained, and there is no bellows-like volumetric pumping as created by wind acting on a bonnet. Leaks are most likely to occur where the duct 22 or bonnet connects to the OGV exhaust pipes 16 or the stack 14 respectively. The amount of exhaust gas which will escape to the atmosphere from a leaking duct connection is extremely small by comparison to leaks in a bonnet connection because the duct connections have a circumference of approximately three feet, which is far shorter than the bonnet connection around the exhaust stack 14, which is 50 feet to 100 feet. It is also much easier to seal to a small round duct than a much larger bonnet.
Further, a bonnet may ingest substantial air through this same interface in addition to exhaust gas leaks around the periphery because the stack itself is not airtight, with numerous openings and gaps which communicate to below-deck spaces. Additionally, the negative pressure inside a bonnet will pull air from the pressurized engine room or other OGV compartments, creating dilution of the exhaust gas and requiring additional fan power to move the greater gas volume, which wastes energy and increases operating costs. The dilution air ingestion with a bonnet also reduces pollutant concentration, making pollutant removal more difficult. The shortcomings of a bonnet are thus eliminated with the exhaust capture system 10 direct connection to the OGV exhaust pipes.
Three additional parallel-flow flexible ducts 22 await deployment. While in the docked state, the additional parallel-flow flexible ducts 22 may be blanked or sealed with a valve or cap to prevent ambient air ingestion into the manifold 20. The manipulator 32 may be attached to the same crane or other structure 24 as the manifold 20, or two separate cranes (or other lifting devices) 24 may support the manipulator 32 and the manifold 20.
A further unique aspect of the exhaust capture system 10 is the means of connecting the parallel-flow flexible ducts 22 to the OGV exhaust pipes 16. Any such connection may include some combination of an alignment means, a securing means, and a means to open and close the parallel-flow flexible duct 22 with a valve depending upon whether it is docked in a cradle or other device, or connected to an exhaust pipe 16, or being transported prior to such connection. The manipulator arm 32 may be used to remove each parallel-flow flexible duct 22 from its dock and place it over an exhaust pipe 16. This placement action may include multiple tasks such as releasing or closing a latch, opening or closing a valve, aligning the flexible duct 22 with and placing it in or over the exhaust pipe 16, latching or otherwise securing it to the exhaust pipe 16, and effecting a seal between the flexible duct 22 and the exhaust pipe 16 to eliminate or minimize exhaust gas leakage to atmosphere.
The sleeve 41 tapers slightly from the open end which fits over the OGV exhaust pipe 16 to the opposite end which is connected to the free end 23 of the corresponding parallel-flow flexible ducts 22. The flexible connecting piece 26a is pulled over the OGV exhaust pipe 16 by the manipulator arm 32. The belt 40 may be an annular coil spring or elastomeric band encircling the sleeve 41 near its midpoint and squeezing the sleeve 41 around the outside surface of the OGV exhaust pipe 16, ensuring a secure attachment. An alternative to the spring or elastomeric band is a circular band, similar to a hose clamp, which is tightened by the manipulator after the flexible connecting piece 26a is positioned over the exhaust pipe. The belt 40 may alternatively be a steel strap clamp attached to the sock and having adjustable circumference, the steel strap clamp actuated by a robotic manipulator arm by actuating a lever which actuates a mechanism which may be a cam, a take-up spool and latch mechanism, or a tightening screw to tighten the sleeve on the OGV exhaust pipe.
The magnets 58 are in the form of a ring concentric with the flexible duct 22. An upside-down U-shaped yoke 56, held and positioned by the manipulator arm 32, centers the magnetic connector 26c and the parallel-flow flexible duct 22 over the OGV exhaust pipe 16, then the manipulator 32 moves the magnetic connector 26c and attached parallel-flow flexible duct 22 forward until the magnets 58 are drawn to the end of the OGV exhaust pipe 16.
The interface plate mechanism 64 comprises a hinged flat plate 65 with a hole in the center slightly smaller in diameter than the OGV exhaust pipe 16. A front face 65a of the interface plate 65 includes a centering cross 66 which preferably is pointed for aligning with the OGV exhaust pipe 16 and one of the parallel-flow flexible ducts 22 is attached to a rear face 65b of the interface plate 65. A pair of lower parallel tubes forming sides of the bottom 60b of the cage 60 straddle the OGV exhaust pipe 16, and as the cage 60 is lowered over the OGV exhaust pipe 16, and the curved tubes forming the ceiling 60a of the cage 60 cause the cage 60 to glide over the OGV exhaust pipe 16 and slide down until the interface plate 65 (centered by the centering cross 66) making contact with an open end of the OGV exhaust pipe 16. The interface plate 65 is pulled forward by springs 68 and the weight of the cage connector 26d seats the interface plate 65 against the open end of the OGV exhaust pipe 16, thereby directing the exhaust gas into the parallel-flow flexible duct 22. The lower end of the cage 60 is weighted by weights 61 to facilitate this process.
At least four different actuation methods are contemplated for the flexible tube connector 26e. In the first method, when the manipulator arm 32 picks up the flexible tube connector 26e by the handles 72a and 72b, the flexible tube connector 26e opens or remains open, and when the manipulator arm 32 lowers the lifting handles 72a and 72b and places the flexible tube connector 26e over the OGV exhaust pipe 16, a spring or weight mechanism twists the flexible tube connector 26e to close the flexible tube connector 26e over the OGV exhaust pipe 16 and holds the flexible tube connector 26e in the closed position until removed by the manipulator arm 32 moving handle 72a into the position shown in
A second method has the manipulator arm pull the end of the sock over the exhaust pipe with handle 72a, then a second action would rotate the end of the sleeve connected to the flexible duct with handle 72b to contract the flexible tube connector 26e to the closed state.
In the third actuation method, the flexible tube connector 26e is relaxed in the closed state until the manipulator arm 32 forces a relative rotation between the handles 72a and 72b to transition the flexible tube connector 26e to the open state, after which a latch, for example one which extends between handles 72a and 72b, is actuated to hold the flexible tube connector 26e in the open state. After the flexible tube connector 26e is positioned over the OGV exhaust pipe 16, the latch is released to tighten the flexible tube connector 26e over the OGV exhaust pipe 16.
The fourth method replaces the sock with a gradually tapered elastomeric tube. The elastomeric tube is pulled over the OGV exhaust pipe 16 by handle 72a until the inner bore of the elastomeric tube makes firm contact with the outer diameter of the OGV exhaust pipe 16, at which time handle 72a is rotated as shown in
In another configuration the ball 90 is carried inside the flexible duct 22 and held in place by a latch which is released when the guide 66 makes contact with the end of the exhaust pipe 16. Tripping this latch releases the weight 90 and may simultaneously give the weight 90 a push into the exhaust pipe 16. Releasing the weight 90 causes the weight 90 to drop into the open end of the OGV exhaust pipe 16. Once the weight 90 is dropped into the OGV exhaust pipe 16, no further action is required to complete and maintain the connection to the OGV exhaust pipe 16. An elastomeric gasket preferably resides on the end of the respective parallel-flow flexible duct 22 to provide a gas tight seal.
The weight 90 may, for example, be a ball at the end of a cable. The leash 92 may alternatively be a heavy multiple segment cable, or a series of weights strung on a cable, and any weight and leash which do not snag on bends in the OGV exhaust pipe. The end of the flexible duct 22 may alternatively be attached to a tapered elastomeric sleeve similar to that shown in
In another embodiment, individual steel balls are attached to the leash at close, regular intervals, which increases the ease of traversing bends in the exhaust pipe. A second parallel leash may be attached to each ball which acts as a safety wire to prevent one or more of the balls from coming loose from the main cable and falling down the exhaust pipe.
Instances of the present invention including flexible connector (or socks) positioned over the OGV exhaust pipe 16 preferably have a relaxed state in which the flexible connectors may be pulled off the OGV exhaust pipes 16 for easy removal in an emergency.
Examples of suitable emissions treatment systems are described in U.S. Pat. No. 7,258,710 for “Maritime Emissions Control System”, U.S. Pat. No. 7,275,366 for “High Thermal Efficiency Selective Catalytic Reduction (SCR) System”, and U.S. patent application Ser. No. 11/092,477 for “Air Pollution Control System for Ocean-going Vessels”. The '366 patent and '477 application are herein incorporated by reference in their entirety and the '710 was incorporated above.
While the invention herein disclosed has been described by means of specific embodiments and applications thereof, numerous modifications and variations could be made thereto by those skilled in the art without departing from the scope of the invention set forth in the claims.
