Fuel expander

A fuel expander which is placed in-line in a fuel supply system for an engine has heat exchange means, which receives heat from an engine component, such as a radiator hose, and transfers the heat to the fuel supply system prior to the fuel reaching the engine. The fuel expander has a mesh screen near the entrance to the fuel expander. Auxiliary heating means may be used with the device.

FIELD OF THE INVENTION 
This invention relates to engine fuel systems generally and is more 
specifically directed to a device which is fitted to a fuel transport 
system, and which expands the fuel to provide increased fuel economy. 
BACKGROUND OF THE INVENTION 
Liquid fuels are used to power many types of engines. Commonly, engine 
fuels are liquid, organic fuels having relatively low boiling points, and 
which readily vaporize. The most common example of such fuels is gasoline, 
although diesel fuel and other petroleum oil derivatives are in common 
use. Alcohols are also in common use as fuels for engines. The most common 
engine with which such fuels are used is the internal combustion engine. 
Piston engines and turbines are in common use, and other types of engines 
use liquid fuels. 
For reasons of economy, and for reasons of the environment, much research 
and investigation has been performed to discover ways to reduce the amount 
of fuel consumed for a given amount of energy produced by an engine. It is 
recognized that by vaporizing the fuel prior to introducing the fuel into 
the carburetor, fuel injection system, or other carburetion system, 
increased fuel mileage is obtained. A device which provides fuel 
vaporization is disclosed in Rocky, U.S. Pat. No. 4,883,040. A vaporizer 
for a liquified petroleum gas engine is shown in Horiuchi, U.S. Pat. No. 
4,434,774. 
Engines which burn liquid fuels inherently produce heat. A heat exchanger 
may be used to vaporize fuel, using heat from the engine. 
SUMMARY OF THE PRESENT INVENTION 
The present invention is a fuel expander. The fuel expander may be a wound 
tube which is positioned in a fuel line or fuel transport means. The 
windings of the round tube may surround a radiator hose or other engine 
component having an elevated temperature during normal engine operation, 
and act as a heat exchanger to introduce heat into the fuel to expand the 
fuel. 
A mesh member, such as a wire screen, is positioned downstream of the fuel 
flow from an entrance point into the device. The device may be of 
increased diameter just ahead of, or upstream of, the position of the wire 
mesh. As the fuel passes through the mesh member, the mesh member has a 
nozzle effect, and in combination with the larger diameter tube, modifies 
the flow characteristic of the fuel. The fuel then begins to travel 
through the wound tube, which acts a heat exchanger. The modified flow 
created by the mesh member and the heat which is introduced into the fuel 
expand the fuel.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring now the drawing figures, FIG. 1 shows the fuel expander. A wound 
tube 2 is connected to a fuel line 4 at an entrance point 6 of the wound 
tube. The fuel line 4 is connected at the exit point 8 of the wound tube. 
In the preferred embodiment, the wound tube is spirally wound, or helically 
wound. As shown, the spiral windings are of constant diameter, and the 
windings are in contact with each other. A goal of the present invention 
is to provide a heat exchange between the engine and the fuel passing 
through the fuel line, and accordingly, winding the tube to form a wound 
tube provides a substantial surface area over which the heat exchange is 
provided. In the preferred embodiment, therefore, the device is a spirally 
wound tube of constant diameter, with the spiral windings in contact with 
each other to maximize the surface area for heat exchange, while 
minimizing the amount of space which the device occupies. 
The supply end of the fuel line 4 is connected to the entrance point 6. The 
tube 2 increases in diameter just past the entrance point. A mesh member 
10 is positioned inside the tube just downstream from the entrance point. 
The mesh member may be formed of wire or synthetic materials which are 
capable of withstanding a constant flow of fuel through the screen or 
mesh. In the preferred embodiment, the mesh is comprised of a fine wire, 
having 20 to 150 openings per square inch. 
The mesh member is positioned within the tube near the location where the 
diameter of the tube is increased. As fuel passes from the smaller and 
more restricted entrance point into the increased diameter part of the 
device, it also passes through the screen. The combination of the screen 
and the larger fuel line create a nozzle effect within the device. At the 
same time, the mesh member is positioned near the point of the device 
where the windings of the spiral round tube begin, and heat is introduced 
into the fuel. 
Heat is supplied to the wound tube, and to the fuel which is traveling 
through the wound tube, by a hose. The hose has an elevated temperature, 
that is, a temperature which is elevated above ambient temperature. 
Most commonly, the present invention will be used with water cooled 
engines. Water cooled engines have hoses through which water is 
transported from the engine to a radiator, and back to the engine. The 
water is cooled as it passes through the radiator or heat exchanger. The 
water is circulated through the engine to collect heat, and then back 
through the radiator. Other cooling agents, such as ethylene glycol, are 
used. Hoses are used for transporting water from an engine to a radiator 
or other heat exchanger, and provide a means for heating the fuel by means 
of the wound tube. 
Hose 12 is inserted through the wound tube. In the preferred embodiment, 
the inside diameter of the wound tube will be sufficiently large to allow 
insertion of the hose, although the wound tube will contact the hose for 
maximum heat transfer between the hose and the wound tube. The outside 
diameter of the tube may, however, be less than the inside diameter of the 
wound tube. 
In the preferred embodiment, the radiator hose which carries water from the 
radiator to the engine is used, however, other engine coolant hoses could 
be used. Pipes or hoses which carry heated gases, such as exhaust gases, 
could be used to provide heat to the wound tube. Accordingly, the term 
"hose" as used herein may also be applied to pipes or similar structures 
which carry liquids or gases of elevated temperatures. 
Auxiliary heating means 14 may be used. The auxiliary heating means may be 
a resistor which is electrically powered. Direct current (DC) batteries 
are frequently used for starting engines and for other purposes related to 
engine or vehicle functions, and the resistor may be powered by such 
direct current batteries, and related charging systems. In some 
applications, external power may be used to provide an electrical energy 
source to the resistor. The resistor may be in a circuit with a 
thermostat. The thermostat may control the resistor so as to cause 
actuation of the resistor when the wound tubes fall below a predetermined 
temperature, or when the ambient air within the housing is below a 
predetermined temperature. The thermostat may be capable of variable 
control to adjust the temperature of the device as desired. Alternatively, 
a rheostat may be used to adjust the temperature level of the resistor. 
The rheostat could be provided with switch means which will allow the 
resistor to be disabled. The auxiliary heating means may be used to 
provide heat to the wound tube when the engine is cold, or in other 
situations where the heat provided by the hose is inadequate. 
The device may be placed within a housing 16. The housing provides 
insulation, which allows heat to be retained around the wound tube, while 
at the same time aiding the hose in providing heat to the outer surfaces 
of the wound tube. At the same time, the housing provides insulation 
between the wound tube and the outside of the device, which increases the 
safety of the device. If a housing is used, openings are provided for the 
entrance and exit point of the wound tube, and for connection of the 
entrance point and the exit point to the fuel line. Controls for the 
auxiliary heating means are accessible. 
In the preferred embodiment, the wound tube is comprised of a material 
having good heat conducting properties. In most applications, the wound 
tube will be comprised of metal. The wound tube may be comprised of 3/8" 
outside diameter cooper tubing. In the most common applications, the 
inside diameter of the wound tube will be between 21/4" and 31/2" inches, 
although the inside diameter may be chosen according to the application. 
Likewise, the inside diameter of the copper tubing will be chosen 
according to the required fuel flow of the particular engine. A typical 
mesh for a smaller engine as used in the mesh member will have 140 to 150 
openings per square inch. The mesh size may range, as an example, from 40 
openings to 150 openings per square inch, with the finer mesh typically 
used with the smaller engines, and the mesh having larger openings used 
with larger engines. A common automotive water hose size is 27/8" outside 
diameter. The housing may be provided with brackets 18 for mounting the 
housing to a vehicle body, or to other structures. 
In the preferred embodiment, the wound tube has eight windings or spirals. 
As an alternative to a housing, or in addition to the housing, an 
insulation material may be positioned around the coils.