Patent Grant
11987336
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Emissions sources produce harmful air contaminants such as particulate matter (PM) and oxides of nitrogen (NOx). The United States Environmental Protection Agency (EPA) and state and local agencies continue to tighten maximum emission limits. In order to meet increasingly stringent regulations, engine and boiler manufacturers and operators install exhaust treatment systems to remove emissions from the exhaust stream before release to the atmosphere.
Emissions sources may contain boilers and/or internal combustion engines. Emissions sources are categorized as either stationary sources or mobile sources. Examples of stationary sources include fixed electrical power generators and power plants. Examples of mobile sources include cars, trucks, tractors, locomotives, boats, ships, oceangoing vessels (OGV's) and mobile electrical power generators.
Many mobile sources are already equipped with close-coupled, dedicated exhaust treatment, where each engine or boiler is equipped with its own exhaust treatment that travels with the mobile source. However, engines and/or boilers on some mobile sources do not have dedicated exhaust treatment that travels with the mobile source. In these cases, a temporarily coupled remote emissions control system may be used. A remote emissions control system may temporarily couple to the mobile source while the mobile source remains in one location but still generates emissions.
One example of temporary coupling to a mobile source is an oceangoing vessel at berth in which the vessel's auxiliary generator(s) and/or boiler(s) continue to operate while at berth. Another example is a stopped or slow-moving locomotive in a railyard which continues to generate emissions. For these types of emissions sources, an emissions control system may couple temporarily to the mobile source at the mobile source's exhaust pipe.
In the case of the vast majority of oceangoing vessels (OGV's), one exhaust pipe is dedicated to each engine or boiler within the OGV. Each exhaust pipe is routed from the engine or boiler, each located in the engine room within the hull of the OGV, up through the ship's stack/funnel, where the exhaust pipes penetrate a deck at the top of the ship's stack. Each of the exhaust pipes extend vertically beyond the deck to sufficiently clear the top of the ship's stack to direct the exhaust away from the OGV.
The top aspect of these OGV exhaust pipes can have various exit configurations ranging from straight up to angled-over by as much as ninety degrees. In a straight up configuration, the exhaust exits vertically and there is no bend at the top aspect of the exhaust pipe. The most common exhaust pipe configuration, by far, is the angled-over configuration. The angled-over configuration is popular because it helps to prevent rain from entering the exhaust pipe. The angled-over configuration also helps to direct the exhaust stream away from the direction of travel, thus helping to keep the exhaust gas away from the vessel when underway.
Angled-over OGV exhaust pipes are typically constructed from a pipe that is cut at an angle into two pieces. One of the pieces is rotated along its longitudinal axis 180 degrees relative to the other piece and then the two pieces are welded back together. This has the effect of causing a bend in the pipe. This procedure may be repeated until the desired shape is achieved. This type of method may be used for many different shapes of angled exhaust pipe exists. A curved piece of pipe also be used to construct an angled-over exhaust pipe.
An early approach to OGV exhaust pipe coupling consisted of an inverted funnel-shaped collection hood which were modeled after typical fume extraction hoods that have been used for many other purposes. Collection hoods in general work on the principle that a slip stream of outside air covers the fumes and draws the fumes with the air into the collection hood. Typically fume extraction hoods are separated by a gap from the fume source.
A disadvantage of collection hoods is the gap between the hood and the exhaust pipe which allows exhaust gas to escape if not counteracted with excessive suction that draws outside air in addition to the exhaust gas. A disadvantage of ingesting this outside air is that it requires the entire system to process significantly more gas (exhaust gas plus outside air). This, in turn, causes the ducting to be larger and the treatment system to be larger which increases capital cost. A further disadvantage of processing the additional gas volume is increased energy cost.
A further disadvantage of collection hoods when used for oceangoing vessels is that both the collection hood and the oceangoing vessel are typically in motion due to rolling, pitching, surging, and/or wind. Thus, when a collection hood is positioned over an exhaust pipe of an oceangoing vessel, there is a tremendous about of relative motion between them, which reduces capture efficiency.
A further disadvantage of the collection hoods is they are only effective for straight up exhaust pipes that exit vertically. An inverted funnel that is typically lowered from above with a crane. In this case, it is relatively easy to align vertical axis of the inverted cone collection hood with the vertical exhaust pipe below. In this case, the force of gravity is parallel with both the axis of the exhaust pipe exit and the axis of the collection hood.
However, if the exhaust pipe is angled-over, then the axis of the collection hood has to be positioned along the same axis of the exhaust pipe exit. In this angled-over case, the force of gravity is no longer parallel with the exit of the exhaust pipe nor the axis of the collection hood. Thus, the force of gravity tends to pull the hood away from the exhaust pipe which requires an opposing force to maintain the position of the collection hood. This is a disadvantage because it is significantly more difficult to maintain the proper orientation of the collection hood both during coupling and while the system is operating. This difficulty is increased during high winds and/or relative motion caused by rolling and pitching motion of the vessel(s).
An angled exhaust pipe exit is typically not cut perpendicular to the longitudinal axis of the exhaust pipe. Most angled exhaust pipe exits are cut so that the exit is vertical in profile or there is even a slight overhang on the top in an effort to reduce the chance of rain entering the pipe from above. Thus, the cross section of an angled-over exhaust pipe exit is likely to be an oval instead of a circle because the pipe is cut at an angle rather than perpendicular across the pipe. In the case of a typical collection hood, however, the shape of the inverted funnel is typically circular. Thus, the shape of and angled exhaust pipe exit does not match the shape of the collection hood, leaving a significant gap on three sides. An oval collection hood cold be built, but then it would not be compatible with the round exhaust pipe exists. Furthermore, if the collection hood is to the side of the exhaust pipe in order to align with the exhaust pipe exit, there will be more opportunity to lose exhaust gas as the hot gas tends to rise vertically and escape between the gap between the exhaust pipe and the collection hood. Thus, an angled-over exhaust pipe when used in conjunction with an inverted funnel collection hood has a significant disadvantage of allowing even more outside air through the gap caused by the shape mismatch and a further disadvantage of losing some of the exhaust gas through the gap. Furthermore, the outside air is drawn into the collection hood asymmetrically, which has the disadvantage of causing a flow disturbance which may reduce the capture efficiency of the hood.
A further disadvantage of collection hoods when used with angled-over exhaust pipes is the hood must be positioned in space in six degrees of freedom (6DOF) (three translational degrees of freedom and three rotational degrees of freedom) in order to align the exhaust pipe exit axis with the collection hood axis.
Thus, there remains a need for a universal temporary coupling device for the extraction of exhaust gas from mobile sources for processing, treatment, and/or testing. Furthermore, it is desirable that the coupling facilitates remote connection, thus eliminating the necessity for person(s) to directly manipulate the coupling onto each exhaust pipe.
A coupling used to temporarily couple to an oceangoing vessel exhaust pipe. Installation and removal of the coupling only uses, in an exemplary embodiment, a simple mechanism with three translational degrees of freedom and only one rotational degree of freedom, thus enabling simple remote coupling. The coupling adapts to a wide array of exhaust pipe shapes and sizes. This is accomplished by a novel and unique shape that allows stable and balanced resting position on top of an exhaust pipe as well as a two-chamber configuration, wherein the two chambers are separated by a permeable partition. Furthermore, the unique shapes of the chambers deflect the exhaust gas stream towards the outlet of the coupling, regardless of exhaust pipe shape, thus increasing capture efficiency and extending the life of an attached fabric flexible hose.
The novel features which are characteristic of the present invention are set forth in the appended claims. However, embodiments, together with further objects and attendant advantages, will be best understood by reference to the following detailed description taken in connection with the accompanying drawings in which:
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent file or records, but otherwise reserves all copyright rights whatsoever.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
In the case of the vast majority ocean going vessels (OGV's), each exhaust pipe is dedicated to a corresponding engine or boiler within the OGV.
The outlet chamber 340 communicates fluidically with the inlet chamber through the permeable partition 330, and in this exemplary embodiment is also wedge-shaped, with an angled bottom surface 344, with top end 344A of surface 344 higher than the lower end 344B. The angled surface 344 tends to deflect horizontal components of the exhaust gas flow toward the outlet. The wedge shape of the outlet chamber is inverted with respect to the wedge shape of the inlet chamber, with a wide aspect extending upwardly, with an outlet at the top for providing an exit for the exhaust gas flow.
In this exemplary embodiment, there is also an attachment device. The attachment device is typically located above the location near the center of mass of coupling 300. The center of mass of coupling 300 is ideally located near the top of the wedge-shaped of inlet chamber 320. In order to maintain this center of mass, additional weight may be added to coupling 300 as required such that coupling 300 balances sufficiently on the exhaust pipe.
The width of coupling 300 is typically slightly wider than the diameter of the largest exhaust pipe diameter that will be coupled to, ensuring a gap between the exhaust pipe and coupling 300. Smaller exhaust pipe diameters than this width will also fit but larger exhaust pipe diameters will not. Thus, coupling 300 will work for all diameter exhaust pipes up to the selected size. However, selecting coupling 300 with unnecessary width is not recommended, as this may result in difficulty when coupling exhaust pipes that are side-by-side. The typical width for coupling 300 for OGV's is about 28 inches, although the actual width will be determined by the application at hand. Larger OGV's with larger auxiliary engines may have larger diameters and smaller OGV's may have smaller diameters. Some exhaust pipes have attachments called “spark arrestors” or “soot screens” which comprise a mesh covering or a grid covering that a larger diameter than the exhaust pipe itself. These exhaust pipe attachments are commonly seen on tanker vessels. When an exhaust pipe outlet attachment is encountered, a corresponding coupling 300 is selected to accommodate the larger size. Furthermore, an expanded area within coupling 300 may be used to accommodate the larger size of the attachment. Furthermore, a special coupling 300 may be fabricated to accommodate any unusual exhaust pipe configurations, while still operating according to the principles discussed herein.
Attachment device 360 (
The material of construction for the skin of coupling 300 in this exemplary embodiment is 18-gauge stainless steel, preferably type 316, in which the shapes are cut, rolled as required, and then welded together. An alternative preferred material for the skin of coupling 300 is titanium. Thinner or thicker gauges may be used depending on the overall size of coupling 300. The metal gauge should be as light as possible to minimize weight but thick enough to prevent denting from normal operation. The material of construction in this exemplary embodiment for permeable partition 330 is stainless steel, preferably type 316, which is fashioned from 0.5-inch diameter round rod in which the resulting grid is has preferred open area of 75%. Non-round stainless-steel rod could be used, but there less chance of galling as the exhaust pipe slides over a rounded shape, at least the aspects facing inlet chamber 320 that potentially contact an exhaust pipe. Different sizes of rods or elongated elements, such as square bars, may be used depending on the requirements at hand. The partition may also be formed of a perforated plate, in another exemplary embodiment. The side of permeable partition 330 the faces inlet chamber 320 consists of vertical rods that at least cover the common opening between inlet chamber 320 and outlet chamber 340. In this exemplary embodiment, the stainless-steel rods extend from the top of the opening between inlet chamber 320 and outlet chamber 340 all the way to the bottom of skirt 310 in order to provide a bearing surface for the exhaust pipe to ride on as coupling 300 is being installed onto an exhaust pipe. Permeable partition 330 should be manufactured so that only vertical rods can make contact with an exhaust pipe, as horizontal rods can catch on the lip of an exhaust pipe as it slides up permeable partition 330 during installation. Therefore, it is recommended that the horizontal reinforcement rods be located on the outlet chamber 340 side of permeable partition 330. Additional stiffening metal may be added around attachment device 360 as required to distribute the weight of coupling 300 to the surrounding structure.
In this exemplary embodiment, a rounded edge, composed of ¼ inch stainless steel rod, is used around the exposed edges at the bottom of skirt 110. This has the benefit of adding rigidity and eliminating a possible knife-edge safety hazard.
In another exemplary embodiment, the skin of coupling 300 may be partially composed of high-temperature fabric suitable for the application. The fabric may be supported by a metal frame. One location anticipated for use of fabric in place of metal is skirt 310. Furthermore, skirt 310 may be flexible such that the skirt material would be drawn toward the exhaust pipe when a vacuum exists within inlet chamber 320 and would be pushed outward when a pressure exists within inlet chamber 320. Thus, skirt 310 serves as seal in vacuum conditions and as a pressure relief under pressure conditions.
A combination of inflatable bellows 610, inflatable balloon(s) 640, and/or flaps 660 may be used in a sealing system 600. For example, the devices shown in
Coupling 300 is considerably simpler to couple onto an angled-over exhaust pipe than the prior art, as fewer degrees of freedom (DOF) are required. The coupling motion may be defined within a Cartesian coordinate system in which the X and Y axes are horizontal, and the Z axis is vertical. The following simple steps are required to install coupling 300 over an angled-over exhaust pipe:
The first step comprises first rotating coupling 300 about the Z axis to roughly align the exhaust pipe exit so that horizontal direction of the exhaust stream is in the same direction as a line drawn from the inlet chamber to outlet chamber. In other words, the exhaust flows in the direction of outlet chamber 340. In the example in
The second step is to position skirt 310 directly above exhaust pipe 112 within the XY plane. Since the opening of skirt 310 is sufficiently large, this does not have to be a precise positioning, and the wedge-shaped inlet chamber 320 will guide exhaust pipe 112 into position. In the example in
The third step is to lower coupling 300 onto exhaust pipe 112 until it comes to rest. The novel and unique wedge shape of inlet section 320 guides exhaust pipe 112 into position once exhaust pipe 112 is located within the perimeter skirt 310. In the example in
Thus, an advantage of coupling 300 is that it requires only three distinct steps and four degrees of freedom (4DOF) to couple, in which only one DOF needs to be operated at a time, which is considerably simpler than in the prior art which required 6DOF concurrently. Thus, the simple positioning mechanism shown in
Thus, an advantage of coupling 300 is that the unique wedge shape of inlet chamber 320 in combination with permeable partition 330 is that it guides the exhaust pipe into the optimum location within coupling 300 with a simple lowering motion. Installation of coupling 300 does not require manual manipulation installation and/or removal by personnel at the exhaust pipe. Coupling 300 enables remote installation and/or removal and is thus advantageous in reducing the amount of time required to couple and decouple, which results in increased overall connected time which increases the amount of emissions treated. Furthermore, remote coupling and decoupling is advantageous because of the reduction of danger to personnel because personnel are not required to manually manipulate the coupling.
X actuator 510 and Y actuator 520 as disclosed in
Z actuator 550 as disclosed in
All three actuators (X actuator 510, Y actuator 520, and Z actuator 550) in this exemplary embodiment are instrumented with position feedback. Thus, the precise position of each coupling 300 may be monitored by the control system such that impending extremes of motion may be signaled to the operator(s). This has the advantage of enabling continual monitoring of the relative locations of each coupling 300 by a control system. Thus, when an OGV raises or lowers in response to cargo loading and unloading, an operator may decide to periodically adjust the location of the main arm in response to changing conditions to center the oscillatory motions of all the couplings being utilized.
The positioning mechanism disclosed in
Coupling 300 completely encloses exhaust pipe 112, unlike prior fume hoods that stood off at some distance resulting in ingested outside air. This results in the advantage of less total gas that must be processed by the treatment system, resulting in smaller ducting and treatment system, thus reducing capital cost and operating cost.
Yet another advantage of coupling 300 is that combination of the aforementioned unique wedge shape of inlet section 320 and permeable partition 330 in combination with a balanced weight distribution maintains coupling 300 on top of exhaust pipe 112 without additional grasping or securing apparatus to maintain the hood on top of the exhaust pipe. Thus, gravity alone is sufficient to maintain the coupling of coupling 300 to exhaust pipe 112. This is an advantage compared to simple fume extraction hoods in which the proper orientation of the collection hood had to be maintained relative to the exhaust pipe using additional mechanisms and controls.
Furthermore, the unique wedge shape of inlet section 320 and outlet section 340 deflects the exhaust stream toward the axis of outlet 342. This has the advantage of preventing loss of exhaust gas out of skirt 310 because the momentum of the gas is deflected away from the opening of skirt 310. Furthermore, exhaust gas does not directly impinge on the walls of a fabric outlet duct attached to outlet 342. Otherwise, if exhaust gas were to directly impinge on the walls of the fabric duct, exhaust gas would be lost through the permeable fabric wall of the duct. Furthermore, if exhaust gas were to otherwise directly impinge on the walls of the fabric duct, the duct would be damaged from excessive heat. Thus, the deflection of exhaust gas caused by the shape of inlet chamber 320 and/or outlet chamber 340 provides an advantage of increased the capture efficiency by preventing loss of exhaust gas through the fabric conduit. A further advantage is the prevention of damage to the outlet duct.
A further advantage of coupling 300 is that it is suitable for use with angled-over exhaust pipes, not just vertical-exit exhaust pipes as in prior fume hoods. Any style of exhaust pipe may be accommodated from vertical-exit to bent-over by 90 degrees. Regardless of the exhaust pipe style, the exhaust gas stream is deflected toward outlet 342.
Inflatable bellows 610 and inflatable balloon 640 may be actuated, once exhaust pipe 112 is in position, with pressurized gas or compressed air via a remote solenoid, for example. The pressurized gas would be allowed to fill the bellows or balloon at a pressure sufficient to maintain a shape that fills the intended gap. To release bellows 610 or balloon 640, the pressure may be released, or alternately a vacuum may be applied to evacuate the gas within bellows 610 or balloon 640. Use of a vacuum would have the effect of flattening the bellows or balloon to the side of walls of skirt 310 which would maximize the opening for easy installation or removal of exhaust pipe 112.
Optional sealing system 600 may improve the capture efficiency of coupling 300 by providing resistance to escaping exhaust gas and may reduce the amount of outside air ingested by providing resistance to incoming air. Note that the purpose of optional sealing system 600 is not to assert any mechanical force to retain coupling 300 onto exhaust pipe 112, because coupling 300 is already mechanically stable on top of exhaust pipe 112 due to the force of gravity in conjunction with the novel shape of chamber 310. Furthermore, optional sealing system 600 may fall short of contacting exhaust pipe 112, but instead only partially fill the area to provide a resistance to air to entering or exhaust to exiting coupling 300. Alternatively, optional sealing system 600 may be used to at least partially seal coupling 300 when not installed on an exhaust pipe 112. This feature would provide the benefit of preventing outside air from being ingested when coupling 300 is not in use, especially if the coupling is one of several couplings that are ultimately connected to the same treatment system.
The above description is intended to enable the person skilled in the art to practice the invention. It is not intended to detail all of the possible modifications and variations that will become apparent to the skilled worker upon reading the description. It is intended, however, that all such modifications and variations be included within the scope of the invention that is seen in the above description and otherwise defined by the following claims.
Accordingly, several advantages of one or more aspects are as follows:
The materials of construction in this exemplary embodiment may also be any form of stainless steel, titanium, or another metal, fabric, or plastic suitable for exhaust temperatures exceeding 1,000 degrees Fahrenheit. Some aspects of coupling 300 may be different from other aspects. For example, the surfaces that deflect exhaust gas may be best suited for metals, whereas other surfaces not subject to exhaust gas stream impact or contact with the exhaust pipe may be plastic or fabric. For example, skirt 310 could be made of fabric in order to save weight. Skirt 310 could also be partially open in some areas.
Other methods of fabrication could be used for at least some aspects of coupling 300, for example, such as deep drawing metal, casting, or molding.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4637300 | Cole | Jan 1987 | A |
| 5980343 | Rolinski | Nov 1999 | A |
| 8402746 | Powell | Mar 2013 | B2 |
| 11325687 | Sharp | May 2022 | B1 |
| 20180290864 | Garitaonandia Aramberri | Oct 2018 | A1 |
| 20220073181 | Sharp | Mar 2022 | A1 |
| Number | Date | Country | |
|---|---|---|---|
| 20220371716 A1 | Nov 2022 | US |
