Abstract:
A combined fuel for use in an internal combustion engine comprises a combination of partially combusted particles from the engine exhaust, said particles being in suspension in ordinary fuel. A method and apparatus for recycling partially combusted particulate material by collecting those materials. The particulate materials are combined with ordinary fuel in the fuel system to form the combined fuel which is filtered and fed the engine for combustion.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of provisional patent application Ser. No. 61/742,341 filed Aug. 8, 2012 by the present inventor. 
     
    
     DISCUSSION OF PRIOR ART 
       [0002]    Internal Combustion engines produce particulate matter which has been always been considered a waste byproduct of combustion and harmful to the environment. Governments around the world have created legislation focused on reducing the level of particulate matter along with Nitrous Oxides (NOx), hydrocarbons and carbon monoxide. To reduce the particulate exiting the tailpipe, the state of the art includes a Diesel Particulate Filter (DPF) to trap the particles in an engine&#39;s exhaust before being released into the atmosphere. 
         [0003]    Commercially available active Diesel exhaust treatment systems utilize a particulate filter which is thermally regenerated. Diesel fuel is a convenient source of energy for such regeneration. During active filter regeneration, the exhaust gas temperature can be increased by combusting an additional quantity of fuel in the exhaust system using specialized hardware and using one of the following methods:
       Flame combustion—the fuel is combusted in a fuel burner, usually with a dedicatedsupply of combustion air, with the flame entering the exhaust system.   Catalytic combustion—the fuel is introduced through an exhaust injector, evaporated and mixed with exhaust gas, and oxidized over an oxidation catalyst.   Combined flame and catalytic combustion—a combination of the above methods, where a fuel burner is followed by a catalytic combustion system. Further details can be found in “Filters Regenerated by Fuel Combustion” by W. Addy Majewski. 1  In short, the removed particulate is burned and creates CO2 which is passed into the atmosphere.  1  Majewski, W. Addy. “Filters Regenerated by Fuel Combustion.” Diesel Technology Guide—Diesel Filter Systems. Dieselnet, 2009. Web. 27 May 2010. &lt;http://www.dieselnet.com/tech/dpf_sys_fuel.html&gt;.       
 
         [0007]    U.S. Pat. No. 7,992,382 describes using a back flow of filtered exhaust gases to regenerate the filter and the removed particulates are sent to a burner. This arrangement also has the disadvantage of creating carbon dioxide without generating usable output work. It would be advantageous to dispose of the removed particulates without using fuel or other energy to burn the particulates. The present invention is directed toward overcoming one or more of the deficiencies of the prior art. 
       BRIEF SUMMARY OF THE PRESENT INVENTION 
       [0008]    Broadly speaking, the present invention is directed toward utilizing the removed particles as a portion of the fuel for the internal combustion engine. Hence, there is proved a combined fuel for use in an internal combustion engine comprising a combination of ordinary fuel and partially combusted particles from the engine exhaust, said particles being in suspension in the ordinary fuel. 
         [0009]    In accordance with the present invention there is provided a method of recycling partially combusted particulate material from an exhaust system of an internal combustion engine by collecting the partially combusted particulate materials and allowing them to agglomerate; deagglomerating the particulate materials and feeding the same into a fuel system of the engine; combining the deagglomerated particulate materials with a fuel in the fuel system to form a combined fuel; filtering the deagglomerated materials and the fuel; and feeding the combined fuel to the engine for combustion thereof. 
         [0010]    In accordance with another aspect there is provided a system for recycling partially combusted particulate material from an exhaust system of an internal combustion engine having a fuel system which includes a receptacle for receiving partially combusted particulate materials removed from the engine exhaust system, said materials being agglomerated; transport means for transporting said agglomerated materials from the receptacle to the fuel system; deagglomerating apparatus associated with the transport means for deagglomerating said agglomerated materials; means for combining the deagglomerated materials with a fuel in the fuel system to form a combined fuel; and means for feeding the combined fuel to the engine. 
       ADVANTAGES OF PRESENT INVENTION 
       [0011]    In accordance with the present invention there is provided a particulate trap regeneration system which provides one or more of the following advantages: 1—transforms a waste byproduct into useable fuel for powering the internal combustion engine; 2—allows certification of high particulate matter producing engine designs such as “massive EGR” or Stoichiometric Compression Ignition (SCI) to stringent emissions standards; 3—removes particulate matter without elevating exhaust temperature levels; 4—allows significant reduction of expensive rare earth elements that have finite known quantities; 5—simplifies a regeneration control system; 6—precludes the thermal gradients in the filter thereby improving reliability and durability; 7—eliminates use of fuel to regenerate the filter thereby improving fuel economy; 8—allows older engine designs (mainly those with lower fuel injection pressures) to meet current emissions regulations; and/or 9—allows retrofitting of legacy engines to meet emissions criteria. 
         [0012]    The resultant benefits are less fuel consumption; potential for commercial availability of low NOx, but high engine particulate matter designs; a less expensive system then (or compared to) thermally regenerated systems which require sophisticated hardware and control systems; elimination of the need for oxidizing the particulate in the filter which by high temperature and subsequent thermal gradients can damage the filter, the intumescent wrap, and any downstream aftertreatment; and reduction and possibly elimination of downtime required for forced active regeneration and ash maintenance. The energy in the particles trapped in the filter are recycled into the fuel where they are combusted providing power from previously waste particulate matter. The present invention allows for an engine to be designed for high particulate matter and low NOx output while still retaining high overall thermal efficiency. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The drawings illustrate the best known mode of carrying out the present invention and show one embodiment of an engine exhaust particulate removal and utilization system incorporating the above advantages and in which— 
           [0014]      FIG. 1  is a diagrammatic illustration of a system embodying the present invention and showing a settling tank that is concurrently filled with fuel as the main tank is filled; 
           [0015]      FIG. 2  is a view, similar to  FIG. 1 , and illustrates the consumption of the fuel from the settling tank to create additional space within the settling tank for maximum regeneration efficiency; 
           [0016]      FIG. 3  is a diagrammatic illustration showing the transport of particulate matter from a particulate filter to the settling tank; 
           [0017]      FIG. 4  is a view, similar to  FIG. 3 , illustrating the settling of the particulate matter to the bottom of the settling tank; 
           [0018]      FIG. 5  is a diagrammatic illustration showing activation of an ultrasonic mixer to begin deagglomeration of the particulate matter; 
           [0019]      FIG. 6  is a view, similar to  FIG. 5 , illustrating the completion of deagglomeration of the particulate matter; 
           [0020]      FIG. 7  is a diagrammatic illustration showing gravity filling of the settling tank with fuel; and 
           [0021]      FIG. 8  is a diagrammatic illustration showing feeding the deagglomerated particulate matter and fuel to the engine for consumption. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]      FIG. 1  illustrates a particulate matter regeneration system operative to create a new fuel that incorporates solid nanoparticles of particulate matter suspended in a regular fuel. When a fuel tank  28  is filled, an embedded settling tank  22  is flooded with incoming fuel  34  so that there is not a loss of total fuel tank capacity. This creates a separate fuel volume designated by the numeral  32 . Of course, separate tanks could be utilized, but this arrangement eliminates a packaging constraint. A normally-open valve  42  in conduit  41  is then closed and a normally-closed valve  40  is opened so that the associated engine (not shown) consumes only the fuel  32  from the embedded settling tank  22  to create a volumetric space required for non-thermal particulate regeneration. An ultrasonic mixer  38  is arranged for use as an ultrasonic level sensor so that the fuel is only removed until a determined level is reached and then valve  42  is opened and valve  40  is allowed to close. Of course a separate level sensor may also be utilized. 
         [0023]    An electronic control module (ECM)  36  determines that regeneration of an associated particulate filter  10  is required. Regeneration utilizing reverse flow of filtered exhaust gas removes particulate matter from the filter. The separated particulate and exhaust gases are blown into the embedded settling tank  22  and pressurizing settling tank  22  to some degree. The pressure is relieved by the vent return line  30  allowing most of the gases minus the particulate matter to be vented back to upstream of the particulate filter. The ECM, after a determined time, turns on the ultrasonic mixer  38 . 
         [0024]    The particulate matter  46  fed to the receptacle or settling tank  22  can be described as nano particles which are agglomerated. Hereafter these are referred to as agglomerated particulate matter particles  46 . The agglomerated particulate matter particles  46  are then hit with alternating high and low ultrasonic pressure waves created by a deagglomerater, for example the ultrasonic mixer  38 . These waves cause cavitation in the fuel and effectively deagglomerate the particulate matter particles to an absolute level below 6-7 microns. If a fuel filter  50  is used in the fuel system, the deagglomeration level is advantageously to a micron size where the particles  46  will pass through the fuel filter  50 . It is believed that the disclosed arrangement can deagglomerate to the original particle size. Preferably a second ultrasonic mixer  38 ′ is placed at the fuel filter  50  to assure deagglomeration of particles  46  to no more than the 2 micron size. It is perceived possible to deagglomerate the particles even to lower levels. If only one ultrasonic mixer is to be utilized, it preferably is mixer  38 ′ located at the fuel filter  50 . Suitable ultrasonic transducers for use as mixers  38  or  38 ′ and arrangement thereof with a fuel filter is illustrated and described in U.S. Pat. No. 8,051,840 B2 issued Nov. 8, 2011 to Timothy J. Cushing, which is incorporated by reference herein in its entirety. Such ultrasonic mixers emit high frequency acoustic waves. 
         [0025]    The mixture of deagglomerated particles  46  and fuel  32  creates a combined fuel in which the deagglomerated partially combusted particles  46  are suspended in ordinary fuel  32  and is then allowed to be diluted with fuel  34  from the main tank  28  by the opening of valve  40 . Valve  42  is then closed and valve  40  opened so that conduit  41  can transport the mixed or combined fuel  32  to fuel line  44  so the engine can consume the fuel  32  and suspended particulate matter  46  by exiting fuel line  44  which will pass through the fuel filter or filters before getting to the injection system. Once the preset fuel level  32  is reached valve  40  is closed and valve  42  is opened. The system is now ready for the next regeneration of the particulate filter. 
         [0026]    It is now deemed apparent that the above-described apparatus causes particulate matter to be broken down to a size that can pass through a fuel filter. The final product of nanometer particles dispersed in the fuel creates a new and useable fuel. 
         [0027]    The above-described apparatus also performs a process which comprises at least some of the following steps the sequence of which may be altered:
       1. Filtering exhaust gases with a particulate filter to remove particulate matter which is contained on the filter.   2. Regenerating the filter by reverse flow of filtered gas and removing the particulate matter therefrom.   3. Collecting the removed particulate matter and feeding it to a settling tank and allowing them to agglomerate. The settling tank may have a volume of liquid fuel therein.   4. Placing the particulate matter and at least a portion of the liquid fuel in proximity.   5. Deagglomerating the particulate materials and feeding the same into a fuel system of the engine. The deagglomeration of the particulate matter may be performed in a portion of the liquid fuel volume to suspend the particulate matter therein.   6. Combining additional liquid fuel with the suspension volume.   7. Feeding the suspended particulate matter into a fuel system.   8. Filtering the combined liquid fuel and suspended particulate matter.   9. Feeding the combined fuel to the engine for combustion thereof.       
 
         [0037]    While the above process steps have been described as used with specific apparatus, it should be understood that the steps are not to be limited to such arrangements and that other apparatus may be utilized to perform the steps, for example utilizing the entire fuel tank as the settling tank and ultrasonically deagglomerating the particulate matter only at the fuel filter, which results in the filling of the fuel tank generating a new suspension of particulate matter settled in the fuel tank. Similarly, the specific steps and their sequence may be modified and/or combined to perform the intended result. 
         [0038]    While the above description is of the best known mode, it should not be construed as any limitation on the scope of the invention, as other variations will become apparent to those skilled in the art and the scope should be determined only by the scope of the appended claims.