Apparatus for reducing hydrocarbon emissions improving efficiency of vehicle internal combustion engines

An apparatus is disclosed for use in a vehicle with a carbureted internal combustion engine having a vacuum inlet port and a fuel inlet port connected to a source of fuel. A heat exchanger is provided having a tank means with an inlet and an outlet, the outlet being connected to the carburetor vacuum inlet and tube means extending through the tank connected intermediate the fuel inlet port and the source of fuel. A source of hot and cold air is connected to the inlet of the heat exchanger and a control means for regulating the amount of hot and cold air entering the inlet of the heat exchanger is also provided in accordance with the temperature of the fuel in the carburetor.

BACKGROUND OF THE INVENTION 
This invention relates to systems for reducing the hydrocarbon emissions 
and improving the efficiency of internal combustion engines. Numerous 
devices have been devised in recent years for reducing the hydrocarbon 
emissions of engines in an effort to make them comply with enacted Federal 
and States laws, however, such systems have, in many instances, severely 
affected the efficiency of the engine and its overall performance. Other 
devices are often costly, complex and require a great deal of maintenance 
or contain components which, in the case of catalytic exhaust converters, 
often operate at undesirably high temperatures. 
It is therefore, the primary object of the present invention to provide a 
new device which is capable of substantially reducing the hydrocarbon 
content of internal combustion engine exhaust emissions while at the same 
time improving or at least maintaining the desired level of engine 
efficiency. 
It is another object of the invention to provide a device which is attached 
to the carburetor of a vehicle engine to reduce the hydrocarbon emissions 
thereof by maintaining the temperature of the fuel in the carburetor at 
between 110 and 115 degrees Fahrenheit. 
It is yet another object of the present invention to provide a device which 
uses no additional energy but makes use of what is wasted in the engine 
cooling and air conditioning systems. 
It is a still further object of the invention to provide a device which can 
be adapted to engines in use without major modification of the structure 
of the engine and which is of relatively inexpensive and simple 
construction. 
These together with other objects and advantages which will become 
subsequently apparent reside in the details of construction and operation 
as more fully hereinafter described and claimed, reference being had to 
the accompanying drawings forming a part hereof, wherein like characters 
of reference refer to like parts throughout the drawing.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT 
In an embodiment of the invention chosen for the purpose of illustration, 
the apparatus indicated generally by numeral 10 is shown comprising an 
internal combustion engine 12 of an automobile or similar vehicle (not 
shown). The engine 12 has an intake manifold 14 upon which is mounted a 
carburetor 16. The carburetor 16 is of the conventional type having an 
inlet port 18 for connection to a source of fuel and a reservoir or bowl 
20 containing an amount of fuel determined by a float actuated valve (not 
shown). The carburetor 16 also has a vacuum port 22 connected by line 24 
to the valve cover 26 of the engine for drawing off engine generated gases 
and mixing them with the fuel mixture entering the engine for the 
combustion of same to further reduce pollution. A pressure-vacuum control 
valve 28 is provided in the line 24 to ensure that the suction in the line 
24 is maintained at a predetermined level. 
A heat exchanger 30 is provided having a cylindrical-shaped outer housing 
32 concentric with a metallic tube 34, preferably copper. The tube 34 is 
connected at one end to a fuel pump 36 by line 38 which in turn is 
connected to a gas tank 40 for delivering fuel to the engine 12 in the 
conventional manner. The other end of the tube 34 is connected by line 42 
to the fuel inlet port 18 of the carburetor via a pressure control valve 
44 the function of which will be fully described later. Washer-shaped 
inserts 46, 48 of elastic material are provided at each end of the heat 
exchanger 30 between the outer housing 32 and the metallic tube 34 to seal 
and prevent air from entering or leaving the area 50. The heat exchanger 
30 has an inlet port 52 extending through the washer insert 48 and an 
outlet port 54 extending through the washer insert 46. In practice, the 
outer housing 32 can be a length of hose having an internal diameter of 
between 0.5 or 0.625 inches which is positioned over the 0.25 inch 
diameter conventional copper fuel line. An overall length of the heat 
exchanger 30 of approximately 3.5 feet has found to be sufficient for 
effective heat transfer. The outlet port 52 is then connected by line 56 
to the vacuum inlet port 22 of the carburetor 16 via line 24. As can be 
seen, air of a predetermined temperature entering inlet port 52 will be 
drawn by the vacuum in line 56 around the metallic tube 34 and out the 
outlet port 54 thereby bringing the temperature of the fuel passing 
through the metallic tube 34 to the temperature of the aforesaid 
predetermined temperature as will now be more fully discussed. 
As is known, warm gasoline will vaporize better in the combustion chamber 
of an internal combustion engine resulting in a more complete burning 
thereof which in turn results in a cleaner burning with less pollutants in 
the exhaust in the form of unburned hydrocarbon particles and carbon 
monoxide. As is also known, as gasoline is heated to a temperature of 
between 110 and 115 degrees Fahrenheit, a vapor will form on the top of 
the gasoline at atmospheric pressure (14.7 pounds per square inch). 
Applicants have thus discovered that if the temperature of the gasoline 
can be maintained in the aforementioned range of between 110 and 115 
degrees Fahrenheit before it is vaporized in the carburetor and if warmed 
air is added through the vacuum inlet port 22, the hydrocarbon emissions 
as well as carbon monoxide in the emitted exhaust can be substantially 
reduced. In addition, the efficiency of the engine in the form of a 
reduction in gasoline consumption can be realized with the use of the 
subject device particularly when the temperature of the gasoline in the 
tank 40 is very cold. For example, if the gasoline in the tank is 
approximately 40 degrees Fahrenheit and it is being delivered to the 
carburetor fuel inlet port 18 by the fuel pump 36 at between 5 and 7 
pounds per square inch pressure, a certain quantity of gasoline will be 
consumed by the engine when it is operating at a certain speed under a 
specific load. When, however, the gasoline is heated in the heat exchanger 
30 to between 110 and 115 degrees Fahrenheit, the gasoline expands raising 
the pressure to between 14 and 15 pounds per square inch with the net 
effect that the fuel pump 36 cannot pump as much fuel to the carburetor 16 
at this elevated pressure as it can when the temperature of the gasoline 
is approximately 40 degrees Fahrenheit. The pressure control valve 44 
serves to limit the pressure of the gasoline entering the bowl 20 to 
approximately 3.5 pounds per square inch. Elevated fuel pressure may 
override the float actuated valve (not shown), controlling the flow of 
fuel to the bowl 20 thus causing increased fuel consumption. If on the 
other hand, the temperature of the gasoline in the fuel tank 40 is between 
95 and 115 degrees Fahrenheit, the temperature under the vehicle hood is 
in the neighborhood of 200 degrees Fahrenheit which in turn causes 
excessive vaporization of the gasoline. Such excessive vaporization also 
results in inefficient engine operation as well as the possibility of a 
"vapor lock" occurring in the fuel system. The subject device will in this 
instance, maintain the temperature of the gasoline in the aforementioned 
range of 110-115 Fahrenheit thus eliminating these problems. 
The means for maintaining the temperature of the air entering the inlet 
port 52 of the heat exchanger 30 and thus the gasoline entering the fuel 
bow 20 constant, comprises a control valve 60 as can best be seen by 
referring to FIG. 2. The control valve 60 has a housing 62 with three 
ports 64, 66, and 68 communicating with the interior of the housing. Port 
64 is connected to a source of cold air, port 68 is connected to a source 
of warm air and port 66 serves as an area for combining quantities of hot 
and cold air before it is delivered to inlet port 52 of heat exchanger 30 
by means of line 134. First and second spaced-apart circular-shaped valve 
seats 70, 72, respectively, are formed in the interior of the housing on 
opposite sides of port 66 which are engaged by a valve head 76 as it is 
moved longitudinally to the right or left as viewed in FIG. 2. A threaded 
end 78 contains a heat responsive element such as spring 80 which is 
operatively connected to the valve head 76. The threaded end 78 is screwed 
into an aperture in the wall of carburetor 16 adjacent the fuel bowl 20 so 
that the temperature of the fuel in the bowl 20 is actually sensed and 
causes the element 80 to respond. A second smaller spring 82 is positioned 
on the other side of valve head 76 to keep it in engagement with valve 
seat 72 at temperatures below 110 degrees Fahrenheit. As the temperature 
of the fuel in the bowl 20 increases above 110 degrees Fahrenheit, the 
valve head 76 is gradually or correspondingly urged away from valve seat 
70 toward valve seat 72. As can thus be seen, when the valve head is 
adjacent valve seat 72, only cold air flows from cold air port 64 through 
to exhaust port 66 to heat exchanger 30 to thereby cool the fuel in line 
34 and subsequently in carburetor bowl 20. As the temperature of the fuel 
in bowl 20 thus decreases, heat responsive element 80 withdraws permitting 
valve head 76 to move to the left as viewed in FIG. 2 thus enabling warm 
air to enter warm air port 68 and mix with cool air. Thus, the fuel in 
bowl 20 will be maintained at the preselected temperature rating of heat 
responsive element 80, namely, 110 to 115 degrees Fahrenheit by means of 
the control valve 60 and the heat exchanger 30. 
The cold air inlet port 64 is connected by line 84 to, in one embodiment, 
the air conditioner system 86 consisting of the major elements of 
compressor 88, condenser coil 90 and evaporator coil 92 present in an ever 
increasing percentage of automotive vehicles. As can best be seen by 
referring to FIG. 3, the line 84 is connected to a heat exchanger 94 
consisting of a cylindrical shaped outer housing 96, preferably made of 
metal, which is substantially concentric with a portion of the low 
pressure or suction line 98 leaving the evaporator 92 of the air 
conditioner system 86. The ends of the outer housing 96 are provided with 
washer-shaped discs 99 of filter material which discs serve to both 
position the outer housing 96 relative to the suction line 98 as well as 
filter out any particles in the air from being drawn into heat exchange 
relationship around suction line 98 as shown by arrows. The force for 
drawing the air into the heat exchanger 94 being, of course, provided by 
the vacuum at carburetor inlet port 22, transmitted via control valve 60. 
In the event the vehicle is not equipped with an air conditioning system, 
an alternative source of cool air can be provided by the device shown 
within phantom lines 100 which consists of a closed cannister 102 
approximately two-thirds full of a fluid 104 such as water. An air pipe 
106 extends from a position toward the bottom of the fluid through the 
cannister wall to the atmosphere. Another pipe 108, connected to cold air 
line 84, extends through the cannister wall to the open space above the 
fluid. Suction in line 84 causes air to be drawn from pipe 106 through the 
fluid where it is cooled and out pipe 108 to inlet pipe 64 of control 
valve 60 via line 84. 
The warm air inlet port 68 is connected by line 110 to, in one embodiment, 
a heat exchanger 112 as best seen by referring to FIG. 4. The heat 
exchanger 112 comprises a cylindrical shaped outer housing 114 preferably 
made of metal having a pipe 116 for connection to line 110. The housing 
114 is substantially concentric with a section of hose 118 which carries 
heated water from the internal combustion engine back to the radiator of 
the vehicle cooling system (not shown). The ends of the outer housing 114 
are provided with washer-shaped discs 120 of filter material which serves 
to filter the air passing therethrough in the same manner as the discs 99 
of exchanger 94. The force for drawing the air into heat exchange 
relationship with heated hose 118, see arrows, is also provided by the 
vacuum at carburetor inlet port 22 transmitted via control valve 60. An 
alternative source of heated air can be provided by the device shown 
within phantom lines 122 which consists of a semi-circular shaped housing 
124 made of metal connected to the exhaust manifold 126 of the internal 
combustion engine. The housing 124 has a length of metal pipe 128, 
preferably copper, connected thereto which in turn is connected to line 
130 running to line 110. Heat from the exhaust manifold 126 is conducted 
into metal housing 124 and copper pipe 128 such that air drawn 
therethrough is heated. Filter material 132 of a heat resistant type is 
placed between the housing 124 and exhaust manifold 126 to filter air of 
particles etc. as it passes therethrough. 
The cooled and heated air or a mixture thereof leaving exhaust port 68 of 
control valve 60 in response to the sensed temperature of the fuel in bowl 
20 as previously discussed, is transmitted to inlet port 52 of heat 
exchanger 30 by means of line 134. 
In a test of the system of the present invention in a 1971 Mark III Mercury 
automobile, without the system installed, the hydrocarbon emissions in the 
exhaust were tested to be 200 parts per million and carbon monoxide of 2 
percent. After the system was installed and operating in the automobile, 
the hydrocarbon emissions were reduced to 100 parts per million and carbon 
monoxide to 0.5 percent. 
Applicants have thus disclosed and now describe in detail their novel 
system for reducing hydrocarbon emissions in the exhaust of internal 
combustion engines as well as improving the operating efficiency thereof 
by maintaining the temperature of the fuel in the bowl of the engine 
carburetor at between 110 and 115 degrees Fahrenheit.