Abstract:
A self-cleaning exhaust component arrangement comprising: an exhaust component ( 100 ); a housing ( 102 ) enclosing the exhaust component ( 100 ); a filter arrangement ( 104, 104′ ) coupled to the housing ( 102 ) to supply the housing ( 102 ) with a flow of filtered air, the filter arrangement ( 104, 104′ ) further comprising a filter element ( 114, 114′ ); wherein the filter arrangement ( 104, 104′ ) is configured to direct air in a first direction through the filter element ( 114, 114′ ) to provide the flow of filtered air, and is further configured to direct the flow of filtered air in a second direction through the filter element ( 114, 114′ ) to thereby clean the filter element ( 114, 114′ ).

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to after treatment devices for internal combustion engines of work vehicles. It also relates to self-cleaning filter systems for such devices. 
       BACKGROUND 
       [0002]    Internal combustion engines used in vehicles face increasingly stringent regulation. The regulations require that the engines produce a low level of pollutants. One way of reducing the pollutants is to provide exhaust components (such as aftertreatment devices) to treat the exhaust gas. These exhaust components operate at elevated temperatures, which can cause their outer surfaces become quite hot. 
         [0003]    Work vehicles, such as agricultural harvesters, generate a great deal of combustible particles that accumulates on free surfaces of the exhaust components. One method of preventing this accumulation is to enclose the exhaust components in a housing. The temperatures can be elevated, however, and therefore air is circulated through the housing to prevent the housing from becoming too hot. 
         [0004]    The air circulated through the housing must be clean, however, and relatively free of the combustible particles generated by the agricultural harvester. Given the small size of the particles, however, it is difficult to filter the air sufficiently clean to prevent particle accumulation on the exhaust component. Due to the large volume of air that must be circulated around the exhaust component, any filter rapidly becomes clogged. If the filter becomes clogged, the temperature of the housing begins to rise, and any combustible particles that have accumulated on the outside of the housing are prone to catch fire. 
         [0005]    Unfortunately, the operator must stop his agricultural harvester, climb down from the operator&#39;s cabin, open the engine covers, clean the filter, return to the operator&#39;s cabin, and begin harvesting again. This is a time-consuming process. 
         [0006]    What is needed, therefore, is an after cleaning device arrangement that requires less maintenance. It is an object of this invention to provide such an arrangement 
       SUMMARY OF THE INVENTION 
       [0007]    In accordance with a first aspect of the invention a self-cleaning exhaust component arrangement is provided comprising: an exhaust component; a housing enclosing the exhaust component; a filter arrangement coupled to the housing to supply the housing with a flow of filtered air, the filter arrangement further comprising a filter element; wherein the filter arrangement is configured to direct air in a first direction through the filter element to provide the flow of filtered air, and is further configured to direct air in a second direction through the filter element to clean the filter element. 
         [0008]    The filter arrangement may comprise a motor coupled to the filter element, the motor being configured to move the filter element from a first position in which a portion of the filter element filters air entering the housing to a second position in which the portion of the filter element is cleaned by air exiting the housing. The motor may be configured to move the filter element from the second position to the first position thereby permitting the portion of the filter element to be reused in the first position after being cleaned in the second position. The filter element may be coupled to a motor to drive the filter element in rotation. The filter element may be in a form selected from a group comprising a disk and a cylinder. The filter element may be in a form selected from the group comprising a generally circular disk and a generally circular cylinder. The exhaust component may be an aftertreatment device. The exhaust component may be a diesel particulate filter. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a side view of an aftertreatment device and housing in accordance with the present invention. 
           [0010]      FIG. 2  is a cross-sectional view of the arrangement of  FIG. 1  taken at section line  2 - 2  in  FIG. 1 . 
           [0011]      FIG. 3  is a cross-sectional view of the arrangement of  FIGS. 1-2  taken at section line  3 - 3  in  FIG. 1 . 
           [0012]      FIG. 4  is a side view of an alternative aftertreatment device and housing in accordance with the present invention. 
           [0013]      FIG. 5  is a cross-sectional view of the arrangement of  FIG. 4  taken at section line  5 - 5  in  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring to  FIGS. 1-3 , an exhaust component arrangement is shown comprising an exhaust component (here shown as an aftertreatment device  100  in the form of the diesel particulate filter) enclosed in a housing  102  that is supplied with air by a filter arrangement  104 . 
         [0015]    The aftertreatment device  100  is a generally cylindrical body. The housing  102  is a generally cylindrical shell that extends around and encloses the aftertreatment device  100 . The filter arrangement  104  is fixed to an upper part of the housing  102 . An air pump or fan  106  is coupled to an inlet conduit  108  to provide the filter arrangement  104  with a flow of air. The inlet conduit  108  conducts air into a filter shell  112  that surrounds a filter element  114 . The filter element  114  is generally in the form of a circular cylinder having a filter media that is corrugated to provide a greater filtering capacity much the same as the combustion air filter of an automobile. 
         [0016]    The filter shell  112  fits closely against the outer surface of the filter element  114  such that air introduced into the filter shell  112  is forced through an inlet surface  116  of the filter element  114  adjacent to an outlet of the inlet conduit  108 . 
         [0017]    Air passing through the filter element  114  is filtered such that the particles entrained in the air are removed and deposited on the inlet surface  116  of the filter element  114 . 
         [0018]    The air, having passed through the filter element  114  in the region of the inlet conduit  108 , is then received by a first filtered air conduit  118 . The first filtered air conduit  118  directs this filtered air downward and into a space  120  formed between the outer surface  122  of the aftertreatment device  100  and the inner surface  124  of the housing  102 . 
         [0019]    The filtered air then flows around the aftertreatment device  100  until it reaches a second filtered air conduit  126 . The second filtered air conduit  126  directs the filtered air back through the filter element  114  in a direction of flow that is opposite to the direction of flow by which the air was initially filtered. As the filtered air passes in the opposite direction through the filter element  114 , the air blows combustible particles off the inlet surface  116  of the filter element  114 . This works to clean the filter element  114  and extend its life. 
         [0020]    In order to clean the combustible particles off the inlet surface  116 , however, the filter element  114  must be rotated with respect to the (stationary) filter shell  112 . To do this, a motor  128  is provided that is coupled (via a shaft  130 ), to the filter element  114 . The motor  128  drives the filter element in rotation, rotating the filter element  114  about its central axis  132 . This moves the portions of the inlet surface  116  (that have previously accumulated combustible particles) from the region of the inlet conduit  108  to the region of the second filtered air conduit  126 . 
         [0021]    The housing  102  surrounds and encloses the aftertreatment device  100  in the embodiment of  FIGS. 1-3  sufficient that the air introduced into the space  120  by the fan  106  increases the pressure in the space  120  sufficient to force at least a portion of the air in the space  120  out of the space  120  and out of the housing  102  through the second filtered air conduit  126   
         [0022]    Referring to  FIGS. 4-6  the aftertreatment device  100  is shown enclosed in the housing  102  that is supplied with air by filter arrangement  104 ′. The filter arrangement  104 ′ is fixed to an upper part of the housing  102 . 
         [0023]    The air pump or fan  106  is coupled to an inlet conduit  108 ′ to provide the filter arrangement  104 ′ with a flow of air. The inlet conduit  108 ′ conducts air into a filter shell  112 ′ that surrounds a filter element  114 ′. The filter element  114 ′ is in the general form of a circular disk 
         [0024]    The filter shell  112 ′ fits closely against the outer surface of the filter element  114 ′ such that air introduced into the filter shell  112 ′ is forced through an inlet surface  116 ′ of the filter element  114 ′ adjacent to an outlet of the inlet conduit  108 ′. 
         [0025]    Air passing through the filter element  114 ′ is filtered such that the particles entrained in the air are removed and deposited on the inlet surface  116 ′ of the filter element  114 ′. 
         [0026]    The air, having passed through the filter element  114 ′ in the region of the inlet conduit  108 ′ is then received by first filtered air conduit  118 ′. The first filtered air conduit  118 ′ directs this filtered air downward and into the space  120  formed between the outer surface  122  of the aftertreatment device  100  and the inner surface  124  of the housing  102 . 
         [0027]    The filtered air then flows around the aftertreatment device  100  until it reaches a second filtered air conduit  126 ′. The second filtered air conduit  126 ′ directs the filtered air back through the filter element  114 ′ in a direction of flow that is opposite to the direction of flow by which the air was initially filtered. As the filtered air passes in the opposite direction through the filter element  114 ′ the air blows combustible particles off the inlet surface  116 ′ of the filter element  114 ′ this works to clean the filter element  114 ′ and extend its life. 
         [0028]    In order to clean the particles off the inlet surface  116 ′, however, the filter element  114 ′ must be rotated with respect to the (stationary) filter shell  112 ′. To do this, the motor  128  is provided that is coupled (via a shaft  130 ′) to the filter element  114 ′ the motor  128 ′ drives the filter element  114 ′ in rotation rotating the filter element  114 ′ about its central axis  132 ′. This moves the portions of the inlet surface  116 ′ (that have previously accumulated particles) from the region of the inlet conduit  108 ′ to the region of the second filtered air conduit  126 ′. 
         [0029]    The housing  102  surrounds and encloses the aftertreatment device  100  in the embodiment of  FIGS. 4-6  sufficient that the air introduced into the space  120  by the fan  106  increases the air pressure in the space  120  sufficient to force at least a portion of the air in the space  120  out of the housing  102  through the second filtered air conduit  126 . 
         [0030]    The figures and explanations herein illustrate two embodiments of the invention. The invention is not limited to the illustrated embodiments, however. To one skilled in the art of corn head design and operation, other embodiments of the invention are also possible.