Note: Descriptions are shown in the official language in which they were submitted.
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MULTI-FUEL SYSTEM FOR INTERNAL COMBUSTION ENGINES
DESCRIPTION
BACKGROUND OF THE INVENTION
[Para 1] The present invention generally relates to fuel systems for an
internal
combustion engine. More particularly, the present invention relates to a multi-
fuel system for an internal combustion engine that utilizes both diesel and
natural gas.
[Para 2] It is estimated that there are currently three hundred million
vehicles
on America's roads. Every day, the average American spends almost an hour
driving in a car. Additionally, approximately seventy percent of goods that
are
shipped in America travel on commercial vehicles. Clearly, automobiles are an
integral part of everyday life in America. The same is true for most countries
around the world. The world's dependence on automobiles creates a similar
dependence on fuel sources to power these automobiles. Most vehicles on the
road today are fueled by gasoline or diesel fuel. Most commercial vehicles are
fueled by diesel fuel.
[Para 3] The reliance on fossil fuels creates a host of problems. Diesel fuel
prices fluctuate on a daily basis, but there is a definite upward trend in
fuel
pricing. There are no indicators to suggest that these fuel prices will go
down
in the foreseeable future. The air pollution problems inherent in the
operation
of gasoline fueled and diesel oil fueled internal combustion engines are well
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known. These air pollutants include carbon monoxide, nitrogen dioxide,
particulate matter, ozone, sulfur dioxide and lead. All these pollutants are
known sources of a wide variety of health problems in humans, as well as
ozone depletion and acid rain in the environment. Many speculate that air
pollution is causing the gradual and irreversible warming of the globe.
[Para 4] For these reasons, various emission control devices are presently in
use, and may be required by federal regulations in order to reduce the amount
of pollutants discharged in the atmosphere by internal combustion engines.
These emission control devices are in response to various Air Quality
Standards
set by the Environmental Protection Agency (EPA), including the Clean Air Act.
Individual states also have their own environmental protection regulations and
methods of enforcement. California's Air Resources Board (CARB) is the
strictest regulatory body concerned with pollution in the country. The
emissions standards set by CARB are stricter than the federal EPA
requirements,
specifically with regard to hydrocarbon and nitrogen oxide emissions, which
become smog. Currently, sixteen other states have adopted, or are in the
process of adopting, California's strict emissions standards.
[Para 5] Emission control devices, however, only remove a portion of the
pollutants and are subject to deterioration with the passage of time. Also,
they
often hinder engines from operating at peak efficiencies. Such emission
control
devices also are somewhat limited in their ability to remove pollutants, and
increase the costs of the automobiles significantly.
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[Para 6] Discharge or burning of blow-by gas also contributes to emissions. In
a diesel powered engine, oil is used to lubricate the crankshaft and
connecting
rod bearings. The crankcase is mainly filled with air and oil. It is the
intake
manifold that receives and mixes fuel and air from separate sources. The
fuel/air mixture in the intake manifold is drawn into the combustion chamber
where it is ignited by a sparkplug, or as a result of compression in the
combustion chamber due to the movement of the piston shaft. Although piston
rings, disposed around the outer diameter of the pistons within the piston
cylinder, are intended to seal off from the crankcase the unburned and burned
fuel and air injected into the combustion chamber, the piston rings are unable
to completely seal off the piston cylinder. Thus, waste gas enters the
crankcase, which is commonly called "blow-by" gas.
[Para 7] Blow-by gasses mainly consist of contaminants such as hydrocarbons
(unburned fuel), carbon dioxide and/or water vapor, all of which are harmful
to
the engine crankcase. The trapping of blow-by gasses in the crankcase allows
the contaminants to condense and accumulate over time in the engine
crankcase. Condensed contaminants form corrosive acids and sludge in the
interior of the crankcase. This decreases the ability of the engine oil in the
crankcase to lubricate the cylinder and crankshaft. The degraded oil that
fails
to properly lubricate the crankshaft components can be a factor in increased
wear and tear in the engine, as well as poor engine performance.
[Para 8] Crankcase ventilation systems have been developed to expel blow-by
gasses out of a positive crankcase ventilation (PCV) valve and into the intake
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manifold to be re-burned. However, such blow-by gasses removed from the
crankcase often contain relatively high levels of lubricating oil and the
like,
which are introduced into the air intake manifold and thus into the combustion
chamber, which increases the pollution generated by the vehicle.
[Para 9] These issues are especially problematic in diesel engines as
diesel
engines burn diesel fuel which is much more oily and heavy than gasoline.
Thus, the blow-by gas produced by the crankcase of the diesel engine is much
more oily and heavy than gasoline blow-by gas. Of course, the burning of such
diesel blow-by gas creates even a greater pollution concern.
[Para 1 0] Recently, there have been found vast sources of natural gas
within
the United States. Natural gas is also sometimes used as a fuel for internal
combustion engines. It has the capability of producing less combustion
pollutants and decreasing engine operating costs without complex emission
control devices. Its use is anticipated to reduce the rate of world fossil
fuel
consumption.
[Para 1 1 ] Since the current transportation infrastructure does not
include
large numbers of widely dispersed retail suppliers of natural gas for
vehicles, it
has been impractical to produce vehicles that are fueled solely by gaseous
fuels
like natural gas due to range limitations. Instead, it is more practical to
equip
vehicles with a supply of both a liquid fuel, such as diesel fuel, and an
auxiliary
supply of gaseous fuel such as natural gas.
[Para 1 2] Accordingly, there is a continuing need for a system which is
capable of burning not only diesel fuel, but diesel fuel combined with natural
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gas so as to lessen the emissions of the diesel combustion engine. What is
further needed is such a system that does so with as little retrofitting as
possible to the existing fuel intake systems and configuration, in order to
lessen the complexity and the cost of the system and also to enable existing
diesel engines to be retrofitted. What is also needed is such a system that
filters the blow-by gas of the diesel engine crankcase, so as to maintain a
clean
and filtered lubricating oil within the crankcase, while lessening the
environmental impact of blow-by gasses that are introduced into the
combustion chamber. The present invention fulfills these needs, and provides
other related advantages.
SUMMARY OF THE INVENTION
[Para 1 3] The present invention is directed to a multi-fuel engine system.
The multi-fuel engine system starts with a diesel engine having a diesel tank
fluidly connected to a combustion chamber by a first supply line. The diesel
engine may include a fuel injector rail and a fuel injector that extends into
the
combustion chamber, in which case the first supply line is fluidly connected
to
the combustion chamber through the fuel injector rail and fuel injector. The
fuel injector is responsive to a microcontroller as described below.
[Para 14] The engine preferably has a plurality of combustion chambers
corresponding to any number of a plurality of pistons in the engine. With a
plurality of pistons and combustion chambers, the engine may also include a
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plurality of fuel injectors extending from the fuel injector rail into each
combustion chamber.
[Para 1 5] The system also has a natural gas tank fluidly connected to the
combustion chamber by a second supply line, which may also pass through the
fuel injector rail and fuel injector if present. The natural gas tank is
preferably
made from a puncture resistant material or carbon fiber. The natural gas tank
and the second supply line are preferably pressurized.
[Para 1 6] The system also has a mixing chamber disposed in-line with the
first and second supply lines, wherein the mixing chamber mixes diesel fuel
from the diesel tank and natural gas from the natural gas tank to form a multi-
fuel mixture before the combustion chamber. A microcontroller is coupled to a
sensor monitoring an operational characteristic of the diesel engine,
particularly engine temperature, battery charge, engine RPMs, rate of
acceleration, exhaust features, or PCV valve position.
[Para 1 7] The mixing chamber is responsive to the microcontroller for
selectively modulating formation of the multi-fuel mixture. The mixing
chamber preferably processes the multi-fuel mixture by expanding, aerating,
pressurizing, heating, or cooling, which is done in response to a signal from
the
microcontroller. The mixing chamber preferably mixes the diesel fuel and the
natural gas in a range from pure diesel to a 1:1 ratio, also in response to a
signal from the microcontroller.
[Para 1 8] The diesel tank preferably includes a diesel level sensor that
is
wirelessly connected to the microcontroller. The natural gas tank also
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preferably has a natural gas level sensor wirelessly connected to the
microcontroller. The microcontroller is configured to selectively modulate
formation of the multi-fuel mixture responsive to signals from the diesel
level
sensor and the natural gas level sensor. The microcontroller is preferably
configured to increase diesel fuel in the mixing chamber in response to
increased torque, increased load, or increased altitude of the engine. The
increased torque, increased load, or increased altitude of the engine is
determined by analysis of the operational characteristic of the diesel engine
by
the sensor.
[Para 19] The system preferably comprises a blow-by gas system comprising
a PCV valve disposed in-line with a recirculating line extending from a
crankcase of the diesel engine to the mixing chamber. The blow-by gas system
further includes an oil filter in the recirculating line between the crankcase
and
the PCV valve.
[Para 20] The system may also include a display device wirelessly connected
to the microcontroller, the diesel level sensor, and the natural gas level
sensor.
The display device is may be configured to display a level of diesel fuel in
the
diesel tank, a level of natural gas in the natural gas tank, and a ratio of
diesel
fuel to natural gas in the multi-fuel mixture in the mixing chamber. The
display device may be a smart phone or a dashboard mounted monitor. The
display device may be configured to receive user input and transmit control
signals to the microcontroller. The control signals may manually modulate
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formation of the multi-fuel mixture. The user input may be received by touch
screen, button, or voice recognition.
[Para 21] Other features and advantages of the present invention will
become
apparent from the following more detailed description, taken in conjunction
with the accompanying drawings, which illustrate, by way of example, the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[Para 22] The accompanying drawings illustrate the invention. In such
drawings:
[Para 23] FIGURE 1 is a schematic illustration of vehicle with a multi-fuel
system of the present invention;
[Para 24] FIGURE 2 is a schematic illustration of an engine incorporating a
multi-fuel system of the present invention;
[Para 25] FIGURE 3 is a schematic illustration of the fuel injector rail
and fuel
injectors of the multi-fuel system of the present invention;
[Para 26] FIGURE 4 is a schematic illustration of the multi-fuel system of
the
present invention;
[Para 27] FIGURE 5 is a schematic illustration of a multi-fuel system of
the
present invention having a microcontroller operationally coupled to numerous
sensors and a PCV valve;
[Para 28] FIGURE 6 is a schematic illustration of the general functionality
of
the multi-fuel system of the present invention;
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[Para 29] FIGURE 7 is an elevational view of the blow-by filter,
illustrating
placement of the intake, exhaust, and oil drainage ports;
[Para 30] FIGURE 8 is an enlarged side view of the area indicated by circle
8
of FIG. 7, illustrating the closed top portion of the canister of the blow-by
filter;
[Para 31] FIGURE 9 is an enlarged fragmented view taken from circle 9 of
FIG.
7, illustrating the bottom portion of the canister of the blow-by filter;
[Para 32] FIGURE 10 is a cut-away side view of the blow-by filter,
illustrating
the filtering assembly with its multiple layers of metal mesh of differing
gauges;
[Para 33] FIGURE 11 is a schematic illustration of an alternate embodiment
of
the multi-fuel system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[Para 34] As shown in the accompanying drawings, for purposes of
illustration, the present invention resides in a dual diesel and natural gas
system for a diesel combustion engine. In accordance with an embodiment of
the present invention, a diesel engine system is converted into a multiple
fuel
engine which operates on a combination of diesel fuel and natural gas fuel. In
a preferred embodiment, the multiple fuel system operates on diesel as a first
fuel and natural gas as a second fuel, being combined with diesel to lessen
emissions. The system of the present invention can also potentially cause a
dramatic increase in engine efficiency, such that the user can keep his car
fueled for much less than it would cost to fuel a standard diesel engine.
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[Para 35] In accordance with the invention, existing diesel engines can be
retrofitted with as little modification to the standard diesel engine as
possible.
For example, the only additions required to the standard diesel engine would
be a tank for the natural gas and fuel line, a mixing chamber for the mixing
of
the fuels, a microcontroller, and in one embodiment a PCV valve and a blow-by
gas filter. Although calibrated fuel injectors may be used, these are not
necessary, and no additional alterations are needed for the actual engine.
[Para 36] With reference now to FIG. 1, the dual fuel system is generally
referred to herein by the reference number 10. A vehicle 12 is shown with an
engine 14, a fuel injector rail 24 and four fuel injectors 26. By and large,
fuel
injection systems have replaced the old carburetor systems. Carburetors
supplied fuel to the engine based on suction, while fuel injection systems
supply fuel via a direct injection spray. The amount of fuel sprayed into the
engine's combustion chamber may correspond to the amount of air entering
the engine, resulting in the fuel injection system making the engine much more
efficient.
[Para 37] Normally, a fuel injection system only functions with one type of
fuel. The dual fuel system of the present invention functions with both
standard
diesel as well as natural gas fuels. The dual fuel system 10 can be
retrofitted
into an existing vehicle, or it can be factory installed into a new vehicle.
The
vehicle 12 illustrated in FIG. 1 is for exemplary and illustration purposes
only.
It will be appreciated that the system 10 of the present invention can be used
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a variety of vehicles and in fact in conjunction with diesel engines which are
not
part of a vehicle.
[Para 38] The system 10 of the present invention requires both the standard
diesel tank 16 as well as a separate natural gas tank 18. The natural gas tank
18 may be made of carbon fiber or some other material that is puncture
resistant and capable of transporting materials under pressure. Typically, the
vehicle is retrofit, such that the natural gas tank 18 is mounted within a
sufficiently large space of the vehicle, the undercarriage of the vehicle 12,
or
any other place where the tank 18 will fit without compromising the safety and
functionality of the vehicle 12.
[Para 39] With reference now to FIG. 2, a partial cross-sectional and
diagrammatic view of a typical engine is shown. Air is received through the
intake manifold 30 into the combustion chamber 38 as the intake cam shaft 42
is drawn up. This creates the vacuum necessary to draw the air in. When the
intake cam shaft 42 is pushed down, fuel is injected into the combustion
chamber 38 by the fuel injector 26. The fuel injector 26 basically acts as an
atomizer, producing a fine spray of fuel that is easily ignited by a glow plug
40
as the piston 32 is raised by the crankshaft 36, compressing the fuel to a
point
of ignition. The resulting combustion forces the piston 32 down into the
crankcase 34, which in turn rotates the crankshaft 36. At this point, the
exhaust camshaft 44 draws back to create the vacuum necessary to drive the
exhaust out of the combustion chamber 38 through the exhaust manifold 46.
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[Para 40] The fuel injector 26 is supplied by the fuel supply line 50 from
the
expansion and mixing chamber 20, which is supplied the diesel fuel 52 from
tank 16 and/or the natural gas 54 from tank 18. Typically, the engine will run
on either diesel fuel from supply line 52 alone, or a combination of diesel
fuel
from line 52 and natural gas from line 54.
[Para 41] Hoses or fuel supply lines 28 interconnect the diesel and natural
gas tank 16 and 18 with a mixing and expansion chamber 20. With reference
now to FIG. 3, the diesel fuel supply from tank 16 is illustrated with its
supply
line 52 to mixing and expansion chamber 20. Similarly, the natural gas supply
tank 18 is shown with supply line 54 to the mixing and expansion chamber 20.
At the expansion and mixing chamber 20, the fuels are aerated and conditioned
as necessary for proper mixing and use. The ratio of each fuel supplied can
vary depending upon engine parameters. The fuel may be heated or cooled in
the mixing chamber 20. The mixed and conditioned fuel is then sent via line
50 either directly to the engine, such as the illustrated fuel injector rail
24
having apertures 56 which lead to the fuel injectors 26 themselves. A
microcontroller or ECU 58 is used to control the input of the fuel through the
fuel injectors 26 into the cylinders of the engine. The electronic control
unit
(ECU) 58 tells the fuel injectors 26 when to inject fuel and how much fuel to
inject. The ECU 58 is typically part of the vehicle's computer control system.
It
is also contemplated by the present invention that the mixed fuel be delivered
to the intake manifold 30 where it will be mixed with a portion of air for
introduction into the cylinder and combustion chamber 38.
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[Para 42] With reference now to FIG. 4, a schematic drawing of the system
of
the present invention is shown. The supplies of diesel fuel 16 and natural gas
fuel 18 are fed into the expansion and mixing chamber 20. A microcontroller
60, with sensor inputs, is used to determine the proportion of diesel fuel to
natural gas fuel at any given time. The conditioning of the mixed fuel, such
as
by aerating, pressurizing, heating or cooling, etc. is also controlled by the
microcontroller 60. The microcontroller 60 may be a separate microcontroller
from the ECU 58, but may also comprise the ECU 58 or a modified ECU 58.
[Para 43] With reference now to FIG. 5, the controller 58 and/or 60 has
sensor inputs to make these determinations. Sensors may include engine
temperature sensor 62, battery sensor 64, a PCV valve sensor 66, an engine
RPM sensor 68, an accelerometer sensor 70, and an exhaust sensor 72. Other
sensors that are typically found in the vehicle and which provide data and
signals to the ECU 58 may also be used. In fact, the data from the sensors may
be fed directly to the microcontroller 60, or to the ECU 58, which then
supplies
the data to the microcontroller 60.
[Para 44] As shown in FIG. 11, an alternate embodiment of the system may
include wireless features for various components. Each of the diesel fuel
supply
16 and the natural gas fuel supply 18 may include a fuel level sensor 16a,
18a.
In addition, each fuel supply 16, 18 may also include wireless antennae 16b,
18b configured to communicate information obtained by the fuel level sensors
16a, 18a. The fuel level sensors 16a, 18a may communicate the information to
a display device such as a dash mounted monitor or smart phone 116. The
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purpose of such a wireless configuration is to permit aftermarket installation
of
the system so as not to require hardwiring into the OEM systems of an engine
or automobile.
[Para 45] The microcontroller 60 may also include an antenna 60a to permit
wireless communication. The microcontroller 60 may wirelessly receive fuel
level information from the sensors 16a, 18a and use that information to
control
the proportion of diesel fuel to natural gas fuel introduced to the mixing
chamber 20 based upon the amounts of each left. The dash mounted monitor
or smart phone 116 may also receive manual input, as by touch screen,
buttons, or similar input devices, to transmit control signals to the
microcontroller 60 so as to manually control the proportion of diesel fuel to
natural gas in the mixing chamber 20. The dash mounted monitor or smart
phone 116 may be provided with an app to give a graphical user interface to
permit manual control of the fuel proportions. The same app may also be
programmed to respond to voice commands to control switching of the fuel
proportions without requiring physical manipulation.
[Para 46] The system may also use the engine sensors 62-72 to detect
engine conditions such as increased torque, increased load, or increased
altitude. In such instances, the microcontroller 60 may adjust the proportions
of diesel fuel and natural gas fuel to a more advantageous mixture. Such
engine conditions would benefit from a greater amount of diesel fuel in a
mixture. The system may be configured to automatically switch to fuel
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proportions based upon the sensing of one or more of increased torque,
increased load, and/or increased altitude.
[Para 47] With reference again to FIG. 3, it will be appreciated that the
present invention contemplates the use of a unique fuel injector rail 24 which
is
designed to supply the combined and mixed diesel and natural gas fuel to the
combustion chambers of the cylinders of the engine. In such case, it is still
contemplated that a single fuel injector 26 will be used in each combustion
chamber of each cylinder of the engine so as to supply the already premixed
fuel supply. It is also contemplated by the present invention that the
existing
fuel intake and injecting system of the engine be used so as to modify the
engine as little as possible to minimize the complexity and expense of
retrofitting the vehicle or engine.
[Para 48] With reference to FIGS. 4 and 5, in a particularly preferred
embodiment a PCV valve 74, which is controlled by microcontroller 60,
regulates the flow of blow-by gasses drawn from the engine crankcase 34 and
supplied to the engine for burning. This may be done, for example, by
regulating the engine vacuum in a combustion engine through a digital control
of the PCV valve 74. The data obtained from the sensors 62-72 by the
controller 58 and/or 60 may be used to regulate the PCV valve 74 as well as an
oil filter 76.
[Para 49] As illustrated in FIG. 4, a filter 76 is used to filter the blow-
by
gasses, thus returning filtered oil back into the crankcase 34 of the engine
14,
while supplying filtered, pure blow-by gas through the PCV valve 74 to be
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burned in the engine 14, such as by introducing the filtered blow-by gas into
the expansion chamber 20 to be combined with the diesel and/or natural gas
fuels. FIG. 11 shows the PCV valve 74 including an antenna 74a. With this
antenna 74a, the state (open/closed) of the PCV valve 74 may be wirelessly
monitored by the microcontroller 60. The microcontroller 60 may also
wirelessly control the state of the PCV valve 74 based upon the sensed
condition of the engine 14.
[Para 50] The oil filter 76 illustrated in the figures herein is typically
in
addition to the regular oil filter, wherein the oil itself is filtered to
remove
contaminants. Instead, this filter 76 is for the filtering of oil from the
blow-by
gas removed from the crankcase. The typically cylindrical filters 76 can be
clamped in place or threaded into place as needed. Off-the-shelf after market
separators or oil filters or the uniquely designed filter 76 illustrated and
described herein can be used. While impurities from the oil may be removed,
such that the oil returned to the crankcase is filtered and will have better
efficacy and life, it is the removal of the liquid oil from the blow-by gas
which is
of particular interest and concern in the present invention in order not to
introduce the oil or contaminants into the combustion chamber, which would
result in increased emissions instead of decreased emissions.
[Para 51] With reference now to FIG. 6, a schematic view of an engine 14
and
the operation of the blow-by filter 76 in conjunction with a PCV valve 74 are
shown. As illustrated, the blow-by filter 76 and the PCV valve 74 are disposed
in-line in a recirculating line 75 between the crankcase 34 of the engine 14
and
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the intake manifold 30 and fuel line 50 of the engine 14. In a diesel engine,
the
intake manifold 30 receives a mixture of fuel and air via fuel line 50 and air
line
78. Fuel line 50 also provides fuel for direct injection into the combustion
chamber 38. In a gasoline engine, the fuel line 50 does not directly inject
fuel
into the combustion chamber 38, rather, the fuel line 50 is only connected to
the intake manifold 30. An air filter 80 receives fresh air 82, which is
delivered
through the intake manifold 30 to a piston cylinder and combustion chamber
38 as the piston 32 descends downwardly within the cylinder 84 from the top
dead center. As the piston 32 descends downward within the cylinder 84, a
vacuum is created within the combustion chamber 38. Accordingly, an input
camshaft 42, rotating at a speed timed with the crankshaft 36 is designed to
open an input valve 88 thereby subjecting the intake manifold 30 to the engine
vacuum. Thus, air is drawn into the combustion chamber 38 from the intake
manifold 30.
[Para 52] Once the piston 32 is at the bottom of the piston cylinder, the
vacuum effect ends and air is no longer drawn into the combustion chamber 38
from the intake manifold 30. At this point, the piston 32 begins to move back
up the piston cylinder 84, and the air in the combustion chamber 38 becomes
compressed. In a diesel engine, fuel is injected directly into the combustion
chamber 38 from the fuel line 50. This injection may be further aided by more
compressed air from a compressed air line 90. The compressed air line 90 is
not present in a gasoline engine. As the air and fuel in the combustion
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chamber 38 is compressed, it heats up until the fuel ignites and combustion
occurs.
[Para 53] The rapid expansion of the ignited fuel/air in the combustion
chamber 38 causes the piston 36 to move downwardly within the cylinder 84.
After combustion, an exhaust camshaft 44 opens an exhaust valve 92 to allow
escape of the combustion gasses from the combustion chamber 38 out an
exhaust manifold 46.
[Para 54] Typically, during the combustion cycle, excess exhaust gasses
slip
by a pair of piston rings 94 mounted in the head 96 of the piston 32. These
"blow-by gasses" enter the crankcase 34 as high pressure and temperature
gasses. Over time, harmful exhaust gasses such as hydrocarbons, carbon
monoxide, nitrous oxide and carbon dioxide can condense out from a gaseous
state and coat the interior of the crankcase 34 and mix with the oil 95 that
lubricates the mechanics within the crankcase 34. As discussed above, the PCV
valve 74 is designed to recycle these blow-by gasses from the crankcase 34 to
be re-burned by the engine 14. This is accomplished by using a pressure
differential between the crankcase 34 and the intake manifold 30. This process
may be digitally regulated by a micro-controller.
[Para 55] PCV valve 74 includes a one-way check valve (not shown) that
opens to allow blow-by gasses through the valve 74 when the vacuum between
the intake manifold 30 and the crankcase 34 is strong enough. With the check
valve open, blow-by gasses pass through the PCV valve 74 to be recycled
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through the intake manifold 30. The check valve can also be controlled by a
microcontroller for added fuel efficiency.
[Para 56] Blow-by gasses are not pure fuel vapors. Rather, when the un-
ignited fuel is pulled into the crankcase 34, past the piston rings 94, the
fuel
vapors mix with the oil 95 that lubricates the mechanics within the crankcase
34. Over time, harmful exhaust gasses such as hydrocarbons, carbon
monoxide, nitrous oxide and carbon dioxide can condense out from a gaseous
state to mix with the oil 95 and the fuel vapors. Thus, the resulting blow-by
gasses contain harmful impurities making them unsuitable for re-burning in
the engine. In a diesel engine, diesel fuel contains more oil than gasoline,
so
the blow-by gasses are significantly oilier. Oily and sludgy blow-by gasses
are
not only non-suitable for re-burn, they also tend to gum up the PCV valve 74
making it impossible for the blow-by gasses to be recycled at all.
[Para 57] Thus, the present invention incorporates a filter 76 to clean the
impurities out of the blow-by gasses before they enter the PCV valve 74. The
blow-by filter 76 also returns filtered engine oil 95 back into the crankcase
34
by return line 77 for further use. In one embodiment, a check valve is used in
the return of the oil back into the crank case. This prevents untreated oil
from
entering into the oil drainage port of the filter 76. Sensors may be used to
detect if the filter 76 becomes too full, and a purging system may be used to
resort back to the OEM. A warning system, including alarms, LED lights, etc.
may be used to notify the operator of such a situation.
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[Para 58] The blow-by filter 76 is particularly illustrated in FIGS. 7-10.
In
FIG. 7, the blow-by filter 76 is shown in a side view. The blow-by filter 76
includes a canister 98 with a closed top portion or lid 100 and a bottom
portion
102. The canister 98 may be made of metal, plastic, or any other material or
composite that is suitable for use in high temperature, high pressure tasks.
The closed top portion 100 of the canister 98 includes a blow-by intake port
104 and a fuel vapor exhaust port 106. The blow-by intake port 104 receives
the blow-by gasses into the interior of the canister 98. The fuel vapor
exhaust
port 106 vents purified blow-by gasses from the interior of the canister 98 to
the PCV valve 74, as illustrated in FIG. 6.
[Para 59] As illustrated in FIG. 7, the closed top portion 100 of the
canister
98 is typically not removable from the canister 98. However, the bottom
portion 102 of the canister 98 includes a removable cover 108 with clamps
110. The removable cover 108 includes an oil drainage port 112 that allows
the purified oil 95 to drain back into the crankcase 34 of the engine 14.
FIGS. 8
and 9 are enlarged views of areas "8" and "9" of FIGS. 7, illustrating the
upper
portion 100 and lower portion 102 of the oil filter canister 98. With
reference
to FIG. 9, the oil drainage port 112 may be offset from the center of the
removable cover 108 in order to account for the angle of the blow-by filter 76
as it is mounted in relation to the vehicle 12. The removable cover 108 allows
for easy access to the interior of the canister 98, making for easy cleaning
and
replacement of the contents of the canister 98.
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[Para 60] With reference now to FIG. 10, the blow-by filter 76 is shown in
a
cut-away side view. Here, the filtering assembly 114 is shown in detail. The
filtering assembly 114 comprises multiple layers of metal mesh 86 of differing
gauges. These layers of metal mesh 86 are loaded into the canister 98 through
the canister's open end, after removing the cover 108. The layers of metal
mesh 86 may be of the same type of metal, or may be of different types of
metal. The types of metal that may be used include, but are not limited to,
steel, stainless steel, aluminum, copper, brass, bronze, etc.
[Para 61] In operation, unfiltered blow-by gasses are received by the blow-
by intake port 104 in the closed top portion 100 of the canister 98. The blow-
by gasses begin to circulate through the layers of metal mesh 86 in the
canister
98. Different contaminants and impurities are trapped at each layer of metal
mesh 86 depending on the gauge of the mesh and type of the metal. Larger
contaminants are filtered by larger gauges of metal mesh 86. Smaller
contaminants and impurities are filtered by the finer gauges of metal mesh 86.
Likewise, some impurities may be trapped by certain types of metal. As the
blow-by gasses work through the filtering assembly 114, contaminants and
impurities are trapped leaving two main byproducts, namely, cleansed engine
oil 95 and purified fuel vapor. The cleansed engine oil 95 eventually collects
in
the bottom portion 102 of the canister 98, where it drains via the oil
drainage
port 112 back to the crankcase 34 of the engine 14. The purified fuel vapor is
vented through the fuel vapor exhaust port 106 in the closed top portion 100
of the canister 98 to pass to the PCV valve 74 to be recycled through the
intake
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manifold 30 or added to the diesel and/or natural gas fuel mixture in the
expansion chamber before being introduced into the combustion chamber 38
of the engine 14.
[Para 62] When the filtering assembly 114 requires periodic cleaning and
maintenance, it can be easily removed from the canister 98 by unlatching the
clamps 110 and removing the lid 108 from the bottom portion of the canister
98. It will be appreciated that the blow-by oil filter 76 may include sealing
gaskets and the like as necessary to create a seal between the canister 98 and
the removable lid 108, so as to prevent oil and other contaminants from
leaking
out. The present invention contemplates that priming might be involved when
changing the oil separator/filter elements of the filtering assembly 114.
[Para 63] The computerized controller 60 can be used to monitor the
filtering process of the blow-by gasses and the PCV valve 74 and so as to
control whether and to what degree the purified blow-by gasses pass through
the PCV valve 74 and into either the fuel line 50, the expansion and mixing
chamber 20 or directly into the air intake manifold 30 or air line 78. In any
event, the blow-by gas which has been filtered presents a much cleaner gas
which produces less undesirable emissions.
[Para 64] Although several embodiments have been described in detail for
purposes of illustration, various modifications may be made without departing
from the scope and spirit of the invention. Accordingly, the invention is not
to
be limited, except as by the appended claims.
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