Patent Publication Number: US-2013228074-A1

Title: Methods and apparatuses for inhibiting backflow of liquid into engine ducts on a ship

Description:
TECHNICAL FIELD 
     The present disclosure generally relates to methods and apparatuses for inhibiting backflow of liquid into engine ducts on a ship, and more particularly relates to methods and apparatuses that provide a secondary basin to hold liquid below entrances to engine ducts. 
     BACKGROUND 
     As is well known, the combustion of hydrocarbon-containing fuels, such as diesel, results in exhaust gases. Before emitting the exhaust gases, they must be processed to remove or reduce levels of pollutants therein. Typically such processing may include particulate removal, scrubbing, or other operations. 
     Because land-based combustion plants are stationary, they need not be designed for tilting or rocking of their components. However, shipboard plants must accommodate for tidal movements, tilting, and rocking As a result precautions not normally taken on land much be made. For instance, shipboard plants must provide for containment of liquids that would otherwise slosh around or move to inappropriate locations in the plants. Further, unwanted motion of liquids within a shipboard plant may result in the backflow of liquid into gas exhaust ducts and even into the plant engine. 
     In light of the above, the present disclosure provides a method and apparatus for inhibiting the backflow of liquid into engine ducts on a ship. Further, the present disclosure provides a method and apparatus for collecting liquids used in a gas processing vessel in a secondary basin positioned below the processing vessel. Alternative or additional features and characteristics of the methods and apparatuses will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background. 
     BRIEF SUMMARY 
     Methods and apparatuses for inhibiting backflow of liquid into an engine duct on a ship are provided. In accordance with an exemplary embodiment, a gas processing apparatus includes an engine producing exhaust gases. The apparatus also includes a processing vessel having a bottom end. The processing vessel is formed with an inlet, a riser having a riser opening, and a liquid outlet positioned between the bottom end and the riser opening. Further, a duct connects the engine to the processing vessel to flow the exhaust gases into the processing vessel. A secondary basin is positioned below the bottom end of the processing vessel. Also, a pipe connects the liquid outlet of the processing vessel to the secondary basin and is configured to flow liquid from the bottom end of the processing vessel into the secondary basin under force of gravity to prevent liquid from entering the riser opening. 
     In another embodiment, a shipboard apparatus for processing gas with liquid includes a processing vessel for processing exhaust gases with the liquid. The processing vessel is formed with an inlet configured to receive the exhaust gases, a riser having a riser opening, and a liquid outlet positioned below the riser opening. Also, the shipboard apparatus includes a secondary basin positioned below the processing vessel and connected to the liquid outlet. In the apparatus, liquid flows out of the processing vessel through the liquid outlet and into the secondary basin under force of gravity to prevent liquid from entering the riser opening. 
     In accordance with another exemplary embodiment, a method is provided for inhibiting backflow of liquid into an engine duct on a ship. The method includes providing a processing vessel having a vessel wall and a bottom end and formed with an inlet, a riser having a riser opening, and a liquid outlet positioned between the bottom end and the riser opening. Further, the method includes providing a secondary basin positioned below the bottom end of the processing vessel. In the method, liquid is collected in the bottom end of the vessel. The collected liquid is flowed out of the vessel through the liquid outlet and into the second basin under force of gravity and liquid is inhibited from entering the riser opening. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary embodiments will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
         FIG. 1  is a schematic view of an apparatus for processing gases on a ship in accordance with exemplary embodiments; 
         FIG. 2  is a cross sectional view of a processing vessel for use in the apparatus of claim  1  in accordance with exemplary embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is merely exemplary in nature and is not intended to limit the methods and apparatuses for inhibiting backflow of liquid into engine ducts on a ship as claimed herein. Furthermore, there is no intention to be bound by any theory presented in the preceding background or the following detailed description. 
     As detailed below, the methods and apparatuses for inhibiting backflow of liquid into engine ducts on a ship utilize a secondary basin positioned below a processing vessel to receive and hold liquid below riser openings in communication with engine ducts. As a result, there is not liquid build up inside the processing vessel and little to no risk of liquid entering riser openings within the processing vessel. 
     In  FIG. 1 , a processing apparatus is shown and generally designated  10 . The processing apparatus  10  is located on a ship  12  having a bottom  13  and includes a diesel engine  14 , a processing vessel  16  such as a scrubber, and a secondary basin  18 . The diesel engine  14  creates a stream of exhaust gases  22  that are delivered to the processing vessel  16  through a duct  24 . Processed gases  26  exit the processing vessel  16  as shown. While the exemplary processing vessel  16  may incorporate any of a variety of means for processing exhaust gases, it is contemplated herein that water, as well as other liquids to enhance processing, is used in processing. As shown, a pipe  30  connects the processing vessel  16  to the secondary basin  18 . As a result, a liquid such as water  32  may exit the processing vessel  16  and flow to the secondary basin  18  through the pipe  30 . The secondary basin  18  is positioned below the processing vessel  16 , i.e., between the processing vessel  16  and the bottom  13  of the ship  12 , such that water  32  will flow from the processing vessel  16  to the secondary basin due to gravity. As shown, the apparatus  10  includes a pump  36  to pump recycled water  38  to the processing vessel  16  for reuse in processing. 
     Referring now to  FIG. 2 , the structure and connections of processing vessel  16  may be more specifically explained. As shown, the processing vessel  16  defines a central axis  40  and has a top end  42  and a bottom end  44 . The bottom end  44  is formed with an inlet  46  in communication with the duct  24  to receive the exhaust gases  22  from the diesel engine  14 . The top end  42  is formed with an outlet  48  through which the processed gases  26  may exit the processing vessel  16 . 
     The vessel  16  can be of any shape, such as cylindrical, rectangular, or other. The processing vessel  16  shown in  FIG. 2  has a wall  51  defining a chamber  52 . A barrier  54  bounds an inlet zone  56  in the chamber  52  at the bottom end  44  of the vessel  16 . The barrier  54  seals the inlet zone  56  from a processing zone  62  above. Specifically, the barrier  54  forms an annular seal with the wall  51 , preventing any liquid flow downward into the inlet zone  56 . The exemplary barrier  54  has a circumference along the wall  51  and a peak  55  at the central axis  40 . The barrier  54  slopes downwardly in each direction from the peak  55  to the vessel wall  51 . In the exemplary vessel  16 , the barrier  54  forms an angle of about 80° with the vessel wall  51  in the processing zone  62  (and an angle of about 100° with the vessel wall in the inlet zone  56 ). Depending on the design of the vessel  16 , the peak  55  will be about six inches to about thirty-six inches higher than the junction of the barrier  54  and the vessel wall  51 . As a result, water will flow downward to the vessel wall  51  despite extreme rocking or tidal action on the ship. 
     Risers  58  pass through the barrier  54  and extend to openings  60  that are positioned in the processing zone  62 . While two risers  58  are illustrated, the vessel  16  can be provided with six, eight, or more risers  58  as desired. Further, in certain embodiments, the vessel  16  will include a riser  58  along the central axis  40  and the peak  55  of the barrier  54  will surround that central riser. As shown, the processing zone  62  is bounded by the barrier  54  and by a second processing mechanism  64 , such as a vapor-liquid contact mechanism or other gas processing device. The exemplary processing zone  62  may include splash or diffusion plates  66 . Each plate  66  is positioned at a riser opening  60  to provide a selected flow path to diffuse the flow of exhaust gases  22  into the processing zone  62 . Further, the plates  66  block or inhibit falling water drops  68  from entering the risers  58 . Typically, any water droplets  68  that enter the risers  58  are atomized and carried back into the quench zone  62  by the flow of exhaust gases  22 . The exemplary vessel  16  is further provided with baffles  72  that inhibit movement of any water collected on the barrier  54 . As shown, the baffles  72  do not contact the barrier  54 , leaving a pathway  73  for liquid to flow along the barrier  54  to the vessel wall  51 . 
     As shown, the vessel  16  is formed with a plurality of water outlets  74  in the vessel wall  51  adjacent the barrier  54 . As shown, the water outlets  74  are formed below the level of the riser openings  60 , i.e., between the riser openings  60  and the bottom end  44  of the vessel  16 . Water  32  landing on the barrier  54  flows toward the vessel wall  51  and out of the vessel  16  through the outlets  74  to the secondary basin  18  under the force of gravity. As a result, water does not rise to the level of the riser openings  60  and cannot backflow into the risers  58  toward the engine  14 . Such backflow is prevented even in rocking conditions experienced by the ship  12  on rough seas. As noted in  FIG. 1 , the water  32  received in the secondary basin  18  may be pumped and recycled to the top end  42  of the vessel  16  for reuse in processing. 
     While the particular methods and apparatuses for inhibiting backflow of liquid into engine ducts on a ship as herein shown and disclosed in detail are fully capable of obtaining the objects and providing the advantages herein before stated, it is to be understood that they are merely illustrative of exemplary embodiments and that no limitations are intended to the details of construction or design herein shown other than as described in the appended claims.