2. Discussion of the Prior Art There are numerous patents directed at increasing the fuel efficiency of some type of combustion source. Some of these patents include patent no. 4,735,186 to Parsons, patent no.

5,074,273 to Brown, patent no. 5,379,728 to Cooke, patent no.

5,408,973 to Spangjer, and patent no. 5,794,601 to Patone.

Accordingly, there is a clearly felt need in the art for a preheat fuel delivery system which has an uncomplicated design, may be easily configured for different types of combustion sources, greatly increases fuel efficiency, and may be used with any type of combustion source without having to make modifications to the combustion source.

SUMMARY OF THE INVENTION The present invention provides a preheat fuel delivery system with an uncomplicated design that greatly increases fuel efficiency. The preheat fuel delivery system includes a fuel processor and a bubbler fuel tank. The bubbler tank includes a fuel container, container cover, inlet supply line, and vapor outlet line. The inlet supply and vapor outlet lines are inserted through the container cover. The inlet supply line continues to a bottom of the fuel container. The vapor outlet line may be flush with a bottom of the container cover. The container cover is sealed to a top of the container. The vapor outlet line is attached to an inlet fuel port of the fuel processor. An outlet fuel port of the fuel processor is connected to an intake manifold through a fuel outlet line.

The intake manifold is attached to an intake port of a combustion source. The intake manifold includes a fuel inlet port and an air inlet port. An air cleaner is preferably attached to the air inlet port.

One end of an exhaust intake line is connected to the exhaust port of a combustion source and the other end of the exhaust intake line is attached to an inlet exhaust port of the fuel processor. One end of an exhaust outlet line is attached to an outlet exhaust port of the fuel processor and the other end is attached to a muffler. The heat from the exhaust of the combustion source heats the vaporized fuel from the bubbler fuel tank. The vaporized fuel is pulled into the intake port of the combustion source by vacuum. The preheated fuel provides a more efficient burning of the fuel.

Exhaust gases from the outlet exhaust port may be fed into the inlet supply line of the bubbler tank to further increase fuel efficiency.

A first embodiment of a fuel processor includes a pair of inlet/outlet plates, at least one heater plate, at least one exhaust transfer plate, and at least one fuel transfer plate.

Each inlet/outlet plate includes a fuel nipple and exhaust nipple for attachment of fuel and exhaust lines. A single inlet/outlet plate terminates each end of the fuel processor.

Exhaust gases from the combustion source flows through an exhaust transfer plate and heats the at least one heater plate.

Fuel flowing through the fuel transfer plate absorbs heat from the at least one heater plate.

A second embodiment of a fuel processor includes a center tube, a middle tube, and an outside tube. Preferably, exhaust gases from the combustion source enter the center tube and exit through the space between the middle and outer tubes. The vaporized fuel enters and exits through the space between the center and middle tubes. The heat from the exhaust gases preheat the vaporized fuel. Accordingly, it is an object of the present invention to provide a preheat fuel delivery system which has an uncomplicated design.

It is a further object of the present invention to provide a preheat fuel delivery system which is easily configured for different types of combustion sources.

It is yet a further object of the present invention to provide a preheat fuel delivery system which greatly increases fuel efficiency.

Finally, it is another object of the present invention to provide a preheat fuel delivery system which may be used with any type of combustion source without having to make modifications to the combustion source.

These and additional objects, advantages, features and benefits of the present invention will become apparent from the following specification.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a side view of a preheat fuel delivery system in accordance with the present invention.

Figure 2 is an exploded perspective view of a fuel processor of a preheat fuel delivery system in accordance with the present invention.

Figure 3 is a side view of a preheat fuel delivery system with a second embodiment of the fuel processor in accordance with the present invention.

Figure 4 is a cross sectional view of a second embodiment of a fuel processor of a preheat fuel delivery system in accordance with the present invention.

Figure 5 is a schematic diagram of exhaust gases being partially fed back into the bubbler air supply line in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference now to the drawings, and particularly to figure 1, there is shown a side view of a preheat fuel delivery system 1. The preheat fuel delivery system 1 includes a fuel processor 10 and a bubbler fuel tank 12. The bubbler tank 12 includes a fuel container 14, container cover 16, inlet supply line 18, and vapor outlet line 20. The inlet supply and vapor outlet lines are inserted through the container cover 16. The inlet supply line 18 continues to substantially a bottom of the fuel container 16. Preferably, the inlet supply line 18 has a valve 19 to control the amount of air entering the bubbler tank 12. The vapor outlet line 20 may be flush with a bottom of the container cover 16. The container cover 16 is sealed to a top of the container 14. The vapor outlet line 20 is attached to the inlet fuel port 22 of the fuel processor 10. An outlet fuel port 24 of the fuel processor 10 is connected to an intake manifold 26 through a fuel outlet line 28. Figure 1 does not show the true position of the outlet fuel port 24 to better illustrate the fuel outlet line 28. The intake manifold 26 is attached to an intake port 102 of a combustion source 100. The intake manifold 26 includes a fuel inlet port 30 and an air inlet port 32. An air cleaner 34 is preferably attached to the air inlet port 32. Preferably, the air inlet port 32 has a valve 33 to control the amount of air entering the intake port 102. Lines are preferably attached to the fuel processor 10 with hose. clamps 46, but other attachment devices may also be used.

One end of an exhaust intake line 36 is connected to the exhaust port 104 of the combustion source 100 and the other end of the exhaust intake line 36 is attached to an inlet exhaust port 38 of the fuel processor 10. One end of an exhaust outlet line 40 is attached to an outlet exhaust port 42 of the fuel processor 10 and the other end is attached to a muffler 44.

Fuel 106 vaporizes in the bubbler fuel tank 14 and enters the fuel processor 10 through the vapor outlet line 20. The fuel 106 is replaced by a gas (such as air or possibly exhaust fumes) entering the inlet supply line 18. The vaporized fuel is pulled through the fuel processor 10 into the intake port 102 by vacuum from the combustion source 100.

With reference to figure 2, the fuel processor 10 includes a pair of inlet/outlet plates 48, at least one heater plate 50, at least one fuel transfer plate 52, and at least one exhaust transfer plate 54. Each inlet/outlet plate 48 preferably includes an exhaust nipple 56 and a fuel nipple 58 for attachment of fuel and exhaust lines. Other methods of attaching lines may also be used. A single inlet/outlet plate 48 terminates each end of the fuel processor 10. It is preferable to have two exhaust transfer plates 54 and two heater plates 50 for a single fuel transfer plate 52 as shown in figure 2. Each heater plate 50 includes a fuel passage 60 and an exhaust passage 62. Each transfer plate includes a passage opening 64 and a transfer area 66.

The jog in the flow path of the exhaust gas through the fuel processor 10 forces the exhaust gas to flow through the transfer area 66 and heat the surface of each heater plate 50.

The jog in the flow path of the vaporized fuel forces thereof to flow across each heater plate 50 and absorb the heat energy therein. The plurality of plates are preferably retained against each other by forming holes 68 in the corners thereof, inserting a threaded stud 70, and tightening a nut 72 on each end of the threaded stud 70, other assembly methods may also be used.

With reference to figure 3, a second embodiment of a preheat fuel delivery system 2 includes a fuel processor 74 and a bubbler fuel tank 12. The vapor outlet line 20 extends from the bubbler fuel tank 12 and is attached to the inlet fuel port 76 of the fuel processor 74. An outlet fuel port 78 of the fuel processor 74 is connected to an intake manifold 26 through a fuel outlet line 28. The intake manifold 26 is attached to the intake port 102 of the combustion source 100. The intake manifold 26 includes the fuel inlet port 30 and the air inlet port 32. Lines are preferably attached to the fuel processor 74 with hose clamps 46, but other attachment devices may also be used.

One end of an exhaust intake line 36 is connected to the exhaust port 104 of the combustion source 100 and the other end of the exhaust intake line 36 is attached to an inlet exhaust port 80 of the fuel processor 74. One end of an exhaust outlet line 82 is attached to an outlet exhaust port 84 of the fuel processor 74 and the other end is attached to a muffler 44.

With reference to figure 4, the fuel processor 74 includes a first end cap 86, a second end cap 88, a center tube 90, a middle tube 92, and an outside tube 94. The tubes are preferably retained concentric to each other. The exhaust gases are preferably routed through the center tube 90, then through the space between the middle and outside tubes. The vaporized fuel is routed through the space between the center and middle tubes.

The tubes are terminated on one end by the first end cap 86 and on the other end by the second end cap 88. The first end cap preferably includes a cover cap 98 and a path cap 96. The path cap 96 retains the tubes and the cover cap 98 is attached to the path cap 96 to seal at least one exposed exhaust passage 110. Vaporized fuel enters the space between the center and middle tubes through the inlet fuel port 76. The vaporized fuel exits through an outlet fuel port 78 formed in the second end cap 88. The exhaust gases enter the center tube 90 through the inlet exhaust port 80 formed in the second end cap 88. The exhaust gases flow through the center tube 90, the at least one exhaust passage 110, and the space between the outer and middle tubes. The exhaust gases in the center tube 90 and the space between the outer and middle tubes heat the vaporized fuel between the center and middle tubes. The exhaust gases exit through the outlet exhaust port 84.

With reference to figure 5, the exhaust may be partially fed back into the preheat fuel delivery system 1 or 2 by connecting the exhaust outlet line 40 to the inlet supply line 18 through a limiting valve 112. The limiting valve controls the amount of exhaust gases entering the inlet supply line 18.

The exhaust gases further increase fuel efficiency. The bubbler tank 12 in either embodiment may be replaced by fuel injection.

While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made without departing from the invention in its broader aspects, and therefore, the aim in the appended claims is to cover all such changes and modifications as fall within the true spirit and scope of the invention.