Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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ANTI-DETONATION FUEL DELIVERY SYSTEM
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of pending PCT application
number PCT/US03/OS635, filed 19 Mar. ~ 2003, which claims priority from
pending US patent application number 10/ 101,250, filed 19 Mar. 2002.
FIELD OF THE INVENTION w
1o This invention relates generally to fuel delivery systems, and
p'ar'ticularly tov a ~ fuel delivery system including' a ~ fuel nozzle
incorporating a
closed STAR' TUBETM, the system providing a ~ fog' "of fuel 'droplets- sized
50
rnicroris and less, and. predorizinantly iri the X10 w= ' 30 micron'range,
while
rniriiini'zirig vapor formation:
BACKGROUND OF THE INVENTION
A large number , of methods for producing fuel-air mixtures for
reciprocating internal combustion engines, such ~-as' Otto cycle engines,
Diesel
engines, 2-stroke engines, Wankel-type engines and any other compression-
2o type engine are well known, and many axe patented. However, as far as
Applicant is aware, many'~previously disclosed methods, except Diesel and jet
engines, attempt to produce a fuel vapor mixed thoroughly with air. In many
of these methods, fuel is heated, in some instances to near a boiling point of
the fuel, in order to convert the fuel to ~ a gas prior to its induction into
a
combustion chamber. Virtually all attempt : to minimize fuel droplet
production and maximize fuel vapor production based on the belief that fuel
droplets in the fuel/air mixture cause inefficient combustion, and generate
more pollutants in the exhaust. ~ In most engines, fuel spray from a
carburator
or fuel injector is simply sprayed into an intake manifold of the engine.
so In gasoline engines, one major drawback to providing a stochiemetric
fuel/air mixture wherein the fuel is in a vapor form is that the vapor
provides
a readily explosive mixture. This becomes a problem when loading on an
engine causes pressures in the combustion chambers sufficient to raise a
temperature of the fuel/air mixture to or beyond its flash point. This in turn
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causes the fuel/air mixture to explode all at once (rather than burning evenly
in an outward direction from the spark plug), a condition commonly known as
"ping", or in older, worn..engines "knock", due to the knocking noise created
as bearings of the piston connecting rods are slammed against the crankshaft
under the force of the explosion. As might be imagined, such a condition is
deleterious to bearings and other parts of the engine, and can greatly shorten
engine life. For pL~rposes of this application, both ping and knock are used
to
refer to a detonation of the fuel vapor/air riZixture in a manner similar to
an
explosion rather than a controlled burn.
1o Where gasoline is simply sprayed into an engine manifold, as from a
carburetor or fuel injector, droplets of all sizes enter the combustion
chamber.
Here, Applicant has discoveired that fuel droplets larger than about 50
microns or so do not burn 'completely, creating unburned hydrocarbon
pollutants: With respect to Diesel and jet fueh incomplete burning also
produces carbon particulate pollution in addition ~ to gaseous hydrocarbon
pollution.
In accordance with '' the present invention wherein a fog of size-
limited fuel droplets of about 50 microns and less predominantly make up the
fuel component of the fuel/air 'mixture, apparatus is provided that processes
2o metered quantities of fuel delivered by a fuel injector; fuel valve (or
other
nozzle) or any other fuel metering device into an aerosol fog having droplets
less than 50 microns in diameter and with a minimum of vapor. As stated,
the object of this invention is to cause internal combustion engines such as
Otto-cycle engines, Diesel engines, two-stroke engines, Wankel-type engines
and other' such engines that compress an air/fuel mixture to operate more
efficiently, with less pollution and without knock than has heretofore been
possible. It has been discovered that fuel droplets of about 50 microns and
less in diameter burn at a slower rate than a fuel vapor/air mixture that
explodes, but significantly faster than the larger liquid fuel droplets
delivered
so by conventional fuel delivery systems currently in use. In addition, it has
been found that these smaller fuel droplets, when thoroughly mixed with air,
burn more stoichiometrically than larger fuel droplets. It is believed a
larger
fuel droplet depletes the surrounding microenvironment of oxygen before
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burning completely, thus creating the unburned hydrocarbon pollutants
found in exhaust gases. In contrast, fuel droplets smaller than about 50
microns in diameter consume surrounding oxygen in a stoichiometric relation
when burned because of their extremely small size, thus the net fuel/air
charge in a combustion chamber is burned completely, rapidly and with little
to no hydrocarbon pollutants. It is also believed that since, in one
embodiment of the instant invention, fuel is initially sprayed into a
generally
confined tube (designated as a STAR TUBETM for purposes of this application)
containing turbulence-inducing devices, vapor saturation of air within the
1o tube prevents further evaporation of the fuel droplets, causing the fuel
droplets to be reduced in size mechanically rather than by evaporation as the
fuel droplets travel~through the tube. Here, as the fuel, and particularly
with
respect to gasoline and other volatile fuels, is released from pressure of the
fuel rail and exposed to the partial vacuum created by the downward travel of
a nearby piston via the open intake valve, lighter, more volatile components
of
the fuel instantly evaporate and increase hydrocarbon vapor pressure within
the tube, suppressing further evaporation of the fuel droplets. In addition,
cooling due to rapid expansion of the evaporating lighter components of the
fuel cools and stabilizes the fuel droplets within the closed environment
2o within the STAR TUBETM.~ The ~ fuel is then processed mechanically by
turbulence-inducing devices in the STAR TUBETM until the droplets reach a
size sufficiently small so as to travel with a localized region of fuel-
saturated
air to the combustion chamber. The fuel/air mixture is thoroughly mixed as
it passes the intake valve and compressed in the combustion chamber,
causing a rapid, even burning of the fuel.
In addition to the foregoing, it is also well known that when a cold
engine is started, only about 1 / S of the fuel is burned. Only after the
engine
warms does it become possible to burn the fuel stoichiometrically. During the
warm-up period, the quantity of unburned hydrocarbon pollutants produced
so by the engine are much greater than in a warm engine. Applicant's system
fox
fuel processing also greatly reduces such pollutants developed by a cold
engine by providing an air/fuel mixture that burns readily and completely.
Engines such as Diesel or other direct injection engines may also
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benefit from fuel processed into droplets sized 50 microns and less. Here, an
aerosol fog of Diesel fuel having droplets of 50 microns and less will burn
faster and ignite easier , than a fuel spray of larger droplets, this fuel fog
increasing efficiency and reducing unburned hydrocarbon pollutants and
particulates in the exhaust of Diesel-type engines. Also, such combustion
properties allow a more stoichiometric proportion of Diesel fuel/air to be
used.
Similarly, turbine and other jet . engines, which typically are sources of
unburned hydrocarbon pollution and particulates because of poor fuel
management, particularly in afterburner modes of operation, may also benefit
1o by fuel provided as a fog of droplets sized 50 microns and less. These
droplets
burn faster and/are ignited easier than would otherwise be the case. This
allows more of a stoichiometric combustion of the jet fuel, reduces
particulates and hydrocarbon pollutants in the exhaust gas, increases the
efficiency the engine and may even prolong life of a jet engine.
~5 In accordance with the foregoing, it is one object of the invention to
provide a fuel delivery system 'that processes fuel into a fuel fog having
fuel
droplets of a . maximum predetermined size. It is another object of the
invention to provide apparatus for generating a fuel/air mixture wherein the
fuel is incorporated into a fog of droplets sized 50 microns and less to as
great
2o an extent as possible, with as little vapor as possible. It is yet another
object
of the invention to provide a closed STAR TUBETM and fuel injector or other
fuel nozzle as a single integral unit or assembly sized so as to be as direct
a
replacement as possible for a conventional fuel injector. Other objects of the
invention will become apparent upon a reading of the following appended
25 specification.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is a diagrammatic view of the fuel delivery system of the present
invention in its operating environment.
so Fig. la is a diagrammatic view showing particulars of construction
related to a different embodiment of the present invention.
Fig. 1b is a diagrammatic view showing particulars of construction
related to another embodiment of the present invention.
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Fig. 2 is a cut-away view of one embodiment of a "STAR TUBETM" of the
present invention.
Fig. 2a is a view of an end of a STAR TUBETM that receives a fuel injector.
Fig. 2b is a cut-away view showing particulars of another embodiment of .
the invention.
Fig. 3 is a top view of a Star Spin and Shear plate of the present
invention.
Fig. 4 is a side view of the Star Spin and-Shear Plate as shown in Fig. 3.
Fig. 5 is a cut-away view of a Star Spin and Shear plate illustrating
1o particulars of operations.
Fig. 6 is a cut-away, diagrammatic view of a cylinder and combustion
chamber of a Diesel engine fitted with a STAR TUBETM of the instant
invention.
Fig. 7 is an embodiment of the invention integrating a STAR TUBETM, air
~ reservoir and a fuel metering valve into a single, integral unit.
Fig. 7a .is another embodiment of the invention integrating a STAR
TUBETM, a smaller air reservoir and a fuel metering system into a single
integral unit.
Fig. 7b is yet another embodiment of the invention integrating a- STAR
2o TUBETM and a fuel metering valve into a single integral unit without a
discrete
air reservoir, with carrier gas supplied from the volume of air and gas within
the STAR TUBETM.
Fig. 8 is a diagrammatic illustration of how a STAR TUBETM may be fitted
to a jet engine.
Fig. 8a is a diagrammatic illustration of another way a STAR TUBETM may
be fitted to a jet engine.
DETAILED DESCRIPTION OF THE DRAWINGS
The basic principle of operation of the present invention involves
3o providing a fuel fog having fuel droplets of a maximum predetermined size
of
from about 50 microns or so in diameter down to just larger than sub-micron
clumps of fuel generally considered to be vapor. While in some fuels, such as
gasoline, formation of some vapor cannot be avoided due to high volatility of
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the lighter components ~of the fuel, it is believed one feature of Applicant's
system minimizes fuel vapor formation and keeps the fuel in droplet form to
as great an extent as possible by creating a cooled fuel vapor-saturated
region
within which the fuel fog is transported, the cooling and saturation of the
region stabilizing the fuel fog and preventing further evaporation of the fuel
droplets. In this form, droplets of a fog are known to be particularly stable,
with diffusion being the primary way droplets dissipate. Here, surface tension
of the fuel droplets in such a fuel fog is believed to also contribute to
prevent
evaporation and dissipation of the fuel droplets until the droplets are
burned.
1o In a most basic embodiment of the invention, and as shown in Fig. 1,
a throttle body or intake manifold 1 is provided with any device 2 capable of
receiving liquid fuels from a fuel tank 3 and associated fuel pump 4 and
processing the fuel into droplets about 50 microns and less in diameter. The
droplets as a fog to an induction air flow of an internal combustion engine or
~5 any other device, such as a space heater or stove, that beneficially may
use
fuel in such a form. Droplets larger than about 50 microns or so may be
returned to tank 3 via line 6. Such oversize droplets may be isolated by
centrifugal force in a. vortex or ,other controlled flow path, or screens
having a
mesh sized to pass the smaller droplets but trap the larger droplets may also
2o be used. As stated, ~ it has been found that a fog of fuel droplets of 50
microns
and less burns faster and cleaner than a spray as provided by a conventional
fuel injector or carburetor, but yet in a controlled manner. In fact, such a
fuel
fog unexpectedly prevents detonation of lower octane fuels in higher
compression engines requiring higher octane fuels, as will be further
25 described.
Pursuant to Applicant's system, devices other than Applicant's
specific apparatus may be used to generate a fuel fog, such as piezoelectric
atomizers, ceramics sieves receiving pressurized fuel, specialized nozzles
such
as SIMPLEXTM nozzles and LASKIN nozzles, air pressure atomizers, rotary cup
3o atomizers, ink jet-like devices that operate using ink jet or bubble jet
technologies, insecticide spray nozzles and other nozzles such as nozzles from
CHARGED INJECTION CORP. of New Jersey. These alternate devices may be
incorporated into a throttle body or intake manifold, either with or without a
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STAR TUBETM of Applicant's design. In addition, devices such as the
NEBUROTORTM available from IGEBA GERAETEBAU CORP. of Germany may
also be used. This device uses a motor-driven rotating blade to break the
liquid fuel into droplets of the desired predetermined size. However, it is
probably desirable to generate the fuel fog in a closed environment so as to
take advantage of vapor saturation and cooling of the environment within
which the fuel fog is created. As such, these devices may be mounted within
some form of tube or housing communicating with the induction air flow. -
Further, other applications of Applicant's STAR TUBETM include spray
to painting, spraying insecticides, herbicides or fertilizer, powder coating
applications and other applications wherein it is desired to break a liquid
into
droplets of a relatively uniform, predetermined size. Furthermore, such
creation of a fog of droplets ~ may be advantageously accomplished in
combination with a gas used as a carrier or vehicle to transport and process
the droplets through a STAR TUBETM. One example of such a process is
wherein a product is formed from binary compounds, with one of the
compounds being a liquid and the other being a gas or vapor. Here, using
Applicant's STAR TUBETM, mixing of the two compounds occurs almost
instantly and in an extremely uniform manner. Such an application may be
2o useful in drug manufacture where a liquid precursor for a drug is treated
with
a gas, such as hydrogen or oxygen. In this application the gas and liquid
precursor may be applied through a STAR TUBETM in a stoichiometric
proportion, as contrasted to currently used methods where the gas is simply
bubbled up through a solution containing the liquid precursor.
Droplet sizes produced by Applicant's STAR TUBETM were measured
by a test rig wherein a STAR TUBETM as disclosed herein and an associated
fuel injector was set up in a simulated throttle body constructed of a
transparent material. A suction device was used 'to draw air through the
simulated throttle body at a rate representative of induction air flow.
so Conventional laser interferometry ,equipment, such as that used to measure
size of pesticide droplets, was used to measure size of the fuel droplets as
they
exited the STAR TUBETM. As stated, a maximum fuel droplet size was found
to be approximately 50 microns, with most of the droplets being in the 10-30
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mlCrOn range.
In one particular embodiment of the instant invention, and by way of
example, part of the induction air flow through an intake manifold of an
engine may be diverted, and utilized to process fuel sprayed by one or more
fuel injectors into droplets sized 50 microns and less to provide the fuel
fog.
This embodiment uses two or more discs, with five discs for each STAR
TUBETM performing best to develop a fog having droplet sizes predominately in
the range of 10 to 30 microns or so, with 50 microns being the ma~~imum size.
Each disk has a central opening, with a series of slits or vanes radially
1o extending away from the central opening and each vane angularly positioned
to spin the diverted induction air flow and fuel droplets. Slits between the
vanes converge with distance from the central opening, forcing the air and
fuel droplets in a flow path through the central opening and slits between the
vanes. For purposes of this application, these plates are variously
enumerated as Star Spin and Shear plates, or simply Star plates. Also, while
some retrofit embodiments disclosed herein utilize conventional fuel injectors
or similar devices, it should be apparent that a fuel injector is simply a
metering valve for liquid fuel, and any fuel metering device for providing
selected quantities of fuel may be substituted for a fuel injector and used in
2o conjunction with Applicant's STAR TUBETM.
Here, a fuel injector may be replaced by any other fuel-management
device, such as a cam activated piston, a solenoid activated piston, or a
variable speed fuel pump. Such a fuel pump may be particularly applicable to
a~ turbine or other type jet engine. Also, any of the aforementioned devices
may be used alone .to develop a fuel fog for mixing with intake air flow for
combustion in an internal combustion engine, ~d advantageously should be
mounted in an enclosure communicating with the induction air flow so as to
saturate and cool the environment within which the fuel fog is created.
The vanes of Star plates create turbulence in the flow path, causing
3o mechanical breakup of the fuel into smaller droplets. Within these combined
actions, the spinning or spiral path creates centrifugal force on the fuel
droplets, forcing them radially outward in the STAR TUBETM where they pass
through narrower portions of the slits between the vanes were turbulence is
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greater, tearing the larger droplets into smaller droplets. As the droplets
become successively smaller as they pass through and by each Star plate, it is
a
believed that the centrifugal and shearing forces overcomes surface tension in
the liquid fuel droplets until an equilibrium point between the centrifugal
and
shearing forces and surface tension of the droplets is reached. Thus, the
mixture may have an induced spin about the axis of the STAR TUBETM, as
well as turbulent spin from passing through the vanes. After exiting the STAR
TUBETM, the resulting aerosol fog is provided to the rest of the induction air
stream and the fuel-air mixture is drawn into a combustion chamber.
1o In addition, and with respect to gasoline-fed engines, the gasoline
used in an engine utilizing fuel injectors is provided to the fuel injectors
under
a significant amount of pressure; typically in the 30 PSI range. Within the
STAR TUBETM, some of the lighter components of gasoline, such as pentane
and hexane, and to some extent heptane, flash into a vapor when released
from the pressure of the fuel rail and become exposed to the manifold
vacuum. This provides cooling to the environment within the STAR TUBETM
during operation. Such cooling retards further evaporation of the fuel
droplets, and stabilizes the fuel fog as it passes through the STAR TUBETM.
Such cooling is believed to be greater than would otherwise be obtainable with
2o a conventional fuel injector by itself, because such a conventional fuel
injector
provides a spray of fuel with much larger droplets that evaporate less, and in
an open environment, as contrasted to the generally closed environment of a
STAR TUBETM. While some cooling of the fuel fog is believed to be beneficial
at normal operating temperatures, in cold weather the fuel, particularly
heavier fuels such as Diesel fuel, may need to be heated in order to flow
properly or provide a cagier gas; as will be further explained. Also, the fuel
may be heated until an engine reaches its normal operating temperature,
which assists in reducing pollutants developed by cold engines.
As stated, the method and apparatus described herein creates a
so stable fuel fog that allows a gasoline fuel vciith ~a lower octane rating
to
unexpectedly be used without knock in a high compression engine that
otherwise would require a liiglier octane fuel. In the instant invention, and
with respect to gasoline, it is~ believed the extent to which knocking of an
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engine is reduced or eliminated is dependent largely on the extent to which
fuel droplet size is controlled. Also as stated, fuel droplets larger than
about
50 microns or so burn in an oxygen-starved microenvironment, causing loss
of power along with production, of hydrocarbon byproducts characteristic of a
"rich" fuel condition. On the other hand, if too much vapor is developed, the
vapor may spontaneously detonate (knock) due to increased engine
compression as the engine is loaded or if the compression ratio of the engine
is higher than specified for the octane rating of the fuel. As stated,
empirically
derived results have demonstrated that an acceptable fuel droplet size for a
to sparked ignition engine is 50 microns and less in diameter down to just
greater than the submicron clumps of fuel generally considered to be vapor.
Within this range, a droplet size of between about 10 - 30 microns or so
appears to be optimal.
In an engine equipped with Applicant's STAR TUBEsTM" and where
exhaust gases are closely monitored by a conventional engine controller, the
more complete, faster and efficient burning caused by the STAR TUBEsTM
causes the engine controller to provide close stoichiometric fuel/air charges.
In contrast, conventional fuel injectors or carburetor-type devices that
provide
a fuel spray containing droplets of larger sizes results in unburned
2o hydrocarbons in the exhaust gases that in turn causes the engine controller
to reduce fuel in the fuel air charges, creating a lean, less than
stoichiometric
mixture that causes the engine .to not produce rated power.
In these modern engines that have a computer and sensor system to
monitor exhaust gas products to determine quantity of fuel to be provided to
the induction air, addition of any of the aforementioned gases or vapors via
the STAR TUBETM to induction air is compensated for by the engine controller
in order to keep the fuel/air mixture at a close stoichiometric proportion.
Further, in the instance where there is a fuel injector for each combustion
chamber, an aftermarket or OEM manifold may be provided with provisions to
3o house the fuel injectors and a respective STAR TUBETM in a position
proximate a respective intake port of a combustion chamber, with possibly an
air scoop or independent induction air channel cast or mounted in the interior
of the intake manifold . to direct an appropriate proportion of 'induction air
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through the STAR TUBETM. Alternately, an amount of gas or vapor serving as
a carrier gas may be controlled, as by a computer such as an engine
controller, to maintain or assist in maintaining a close stoichiometric
fuel/air
mixture or to increase or decrease a flow of motive gas through the STAR
s TUBETM to compensate for changes in induction air flow, as when the
accelerator pedal is depressed to a greater or lesser degree. Also, mechanical
linkages coupled to valuing apparatus may be employed for such increases
and decreases in the motive flow through the STAR TUBETM.
In gasoline engines specifically designed as "lean burn" engines,
1o excess air is mixed in the fuel/air charge. In these engines, the fuel fog
consisting of droplets 50 microns and less burns more rapidly and more
completely than would otherwise be the case. Thus, with STAR TUBES(TM),
these engines operate more efficiently and produce less pollution, and with
little or no detonation.
~5 As described herein, Fig. la illustrates, by way of example, one
possible embodiment of a STAR TUBETM 10. The STAR TUBETM 10 is
mounted between a conventional fuel injector 12 and injection port 14 in a
throttle body 16 (dashed lines) or in a port of an intake manifold of an
internal
combustion engine near a respective intake valve, or in the case of a two-
2o stroke engine an intake port. Conventionally, a fuel injector 12 is fitted
to
injection port 14 so as to provide a spray of fuel to induction air, as
indicated
by arrows 18, flowing through the throttle body and intake manifold. As
shown, one end B of STAR TUBETM 10 is configured as a fuel injector port to
receive the injection end of a fuel injector 12, with the other end A of the
STAR
25 TUBETM configured as a fuel injector tip so as to be mountable in the fuel
injection port 14 that otherwise would receive the fuel injector. In some
currently manufactured engines; there is more than one fuel injector mounted
in respective ports of a throttle body, the throttle body providing fuel to
all the
cylinders of the engine. In this instance, there is a STAR TUBETM for each
3o respective injector. A portion of the induction air 18 flowing through the
throttle body (or intake manifold) 16 enters openings O in end B of the STAR
TUBETM to create a carrier flow of gas that develops turbulence and shearing
forces as described in order to break up the fuel droplets into a fog. In
other
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engines where there is a fuel injector and corresponding injection port for
each combustion chamber, these ports are typically located in the intake
manifold proximate to a respective intake port or valve, with the fuel
injector
body mounted outside the intake manifold. Here, and as stated, the STAR
TUBETM may be configured at this end A as a fuel injector to fit the fuel
injector port, and be configured at the other end B as a fuel injector port so
as
to receive the injecting end of a fuel injector. In this instance, a portion
of the
induction air may be directed and routed through the STAR TUBETM so as to
create a motive airflow therethrough, or a carrier gas may be provided
to independently of the induction air flow. This carrier gas may be separate
from
the induction airflow, and may be an inert gas such as dry nitrogen or
filtered
atmospheric gases, or a combustible gas such as propane or butane. Where
propane and butane are used as a carrier gas, an octane rating of a fuel/air
charge containing a liquid fuel of a low octane rating is beneficially
increased
due to the higher octane ratings of propane and butane. In other
embodiments, the carrier gas may be or include an oxidizing gas such as
nitrous oxide, which may be supplied through the STAR TUBETM, this flow
being of a sufficiently high rate so as to generate turbulence to mechanically
break the fuel droplets into smaller droplets having a size within the
2o predetermined range as described above, and expel the fuel particles from
the
STAR TUBETM. When a motive flow of gas is provided from an external
source, the gas flow may be continuous, or pulsed ON and OFF by using the
ON-OFF signals provided to the fuel injectors, possibly with a short delay to
allow the fuel droplets to clear the STAR TUBETM. Likewise, the portion of
induction air flow may be switched ON and OFF corresponding with the fuel
bursts from the fuel injectors.
As shown'in the embodiment of Fig. 1b, a supply of gas 22 may be
coupled to closed STAR TUBEsTM via a metering valve 24 and may be
energized ON and OFF responsive to signals to the fuel injectors. An annular
so hollow collar 20 receives the gas from valve 24, and may be simply left
open
on a bottom side thereof, or may be provided with interior openings O that
,,.communicate with an upper interior end of the STAR TUBETM. An injector 12
sealably fits in the opening of the annular collar 20 and communicates with
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an interior of the STAR TUBETM. As stated, valve 24 may be operated to
release a burst of gas in conjunction with the fuel injector being energized
to
release a spray of fuel. In other instances, such as in turbines and other
types of jet engines, the gas may simply flow continuously through the STAR
TUBETM in conjunction with a continuously metered flow of fuel from the fuel
nozzle of the jet engine. In this, embodiment, and referring to Fig. 8, the
fuel
supply 250 is coupled to a fuel pump 252, which provides the jet fuel to a
STAR TUBETM 254 that may be configured generally as described for Fig. 1b,
except the STAR TUBETM construction is optimized for turbine and jet engines
and constructed of materials consistent with jet engine design. Here, STAR
TUBETM 254 may be mounted in combustion chamber 256 generally where
the fuel nozzle for the jet engine would be located. A small amount of
compressor bleed air may be taken from the compressor portion 258 of the jet
engine and applied through the STAR TUBETM as a carrier gas a shown in Fig.
1b. In a jet engine having multiple fuel nozzles, there would be a STAR
TUBETM for each fuel nozzle. In some instances, a different source of
compressed gas, such as ram air, may also be used. In addition, and as
described above, a gas having beneficial or selected properties, such as
nitrous oxide, may temporarily be used as all or some of the carrier gas to
2o provide a temporary boost in power, or a gas that would temporarily reduce
or
eliminate pollution may be temporarily included in the carrier gas to promote
more complete combustion in locations where pollution from a jet engine is a
problem. In addition, certain liquids that would flash into a vapor upon being
exposed to heat from the combustion chamber, such as alcohol, may be used
to develop a carrier gas. Other gases or liquids, such as water, that may have
beneficial properties may also be used, either continuously or on a temporary
basis. Ideally, but not necessarily, the proportion of gas to fuel in a jet or
turbine engine would be .such that the fuel/air proportion is too rich to burn
inside the STAR TLJBETM and would produce a dense fog of jet fuel that would
3o burn more efficiently and completely than can be accomplished by current
methodsof jet fuel managerinent in a jet Also, it may that
engine. be an
optimumdroplet size may be different fox turbine enginesthan
jet or for
sparkedignition engines. Here, droplet be adjusted a jet
size may for or
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turbine engine by providing a larger STAR TUBETM with more or fewer Star
Spin and Shear plates and adjusting size of the central opening and slits.
Such sizing of the Star plates and tubes is true for other engines and fuels.
Here, smaller slits and more Star plates develops smaller fuel droplets, while
larger slits and fewer plates produce larger droplets. Also, a rate of carrier
gas
flow through a STAR TUBETM affects droplet size, with faster flow producing
smaller droplets and slower flow producing larger droplets. Fig. 8a
illustrates
a STAR TUBETM 254, installed in a jet engine wherein the STAR TUBETM is
closed to external carrier gas. Here, the fuel flows through a heater 260,
to which may be heated by combustion temperatures .in the burn chamber 256
of the jet engine. So heated, a portion of the fuel flashes into vapor when
applied to the STAR TUBETM, providing a carrier gas that processes the
remainder of the liquid fuel passing through the STAR TUBETM.
By using STAR TUBEsTM in a jet engine to convert fuel into a fog, it
should be apparent that the fuel may be controlled so as to produce more
efficient and stoichiometric burning, in turn increasing efficiency, reducing
pollutants and conserving fuel.
In yet other embodiments such as in gasoline engines, it has been
found that external carrier gas is unnecessary, with a motive flow of gas
2o through the STAR TUBETM provided by ambient gas or air within the STAR
TUBETM, and by lighter components of the liquid fuel flashing into vapor. In
these embodiments wherein no external carrier gases are provided, it has
been found that lighter components of gasoline fuel flashing into vapor cools
the environment within the STAR TUBETM to between about 35 - 45 degrees
Fahrenheit. As stated, this stabilizes the fuel fog. Also, vacuum developed by
the engine assists in flashing the lighter components of the fuel into vapor.
Here, as the spray of fuel is provided by the fuel injector, the associated
piston
begins its downward travel on the intake stroke, creating a partial vacuum in
the intake manifold that is felt by the volume of air in the STAR TUBETM. As
so the partial vacuum increases due to the piston continuing its downward
travel, air and fuel vapor, along with fuel droplets from the fuel injector,
are
drawn outward, pulling and processing the fuel droplets through the STAR
TUBETM. After the intake valve closes, the partial vacuum dissipates, allowing
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air in the intake manifold to re-enter the STAR TUBETM. Of course, this
action is in addition to any fuel vapor developed as described, and which
contributes to carrier gas flow. This embodiment is useful in retrofit
applications as only a closed STAR TUBETM need be mounted between each
fuel injector and its respective port. In all instances, the STAR TUBETM and
fuel injectors assemblies are mounted and supported by brackets or other
similar structure (dashed lines , in Fig. la), as should be apparent to one
skilled in the art.'
With reference again to Fig. 1a, and as described, a STAR TUBETM 10
1o may be mounted in the throttle body or intake manifold 16 between a
respective fuel injector and an 'associated injector port. Typically, the
liquid
fuel is pumped by low-pressure fuel pump 26 in a fuel tank to a high-
pressure fuel pump 28, on the order of about 30 PSI or so, which
conventionally develops fuel pressure and flow as shown to the fuel injectors
12. Injectors 12 produce bursts of fuel spray as controlled by an engine
controller (not shownj, which determines both duration and timing of the
bursts of fuel. These bursts of fuel spray are fed directly into STAR TUBEsTM
10 where the fuel spray is processed into a fuel fog of smaller droplets of SO
microns and less in diameter, and subsequently fed into the throttle body,
2o intake manifold or any other regions in which fuel would be appropriately
injected. Induction air and the fuel fog as developed by the STAR TUBETM is
then drawn into a combustion chamber (not shown). The fuel feeding the fuel
injectors may be' conventionally regulated to a constant pressure by fuel
pressure regulator 30, which relieves excess pressure by controllably bleeding
high-pressure fuel via return line 32 to fuel tank 34 as shown by arrow 36,
along with any vapor that has formed within the high-pressure feed line or
fuel rail. Of course, and as stated, any of the devices shown and described
for
Fig. 1 may be substituted for the STAR TUBETM 10, preferably v~ithin a closed
environment communicating with the induction air flow.
3o Fig. 2 shows a cross section of one of STAR TUBEsTM 10. Initially, at
an end B of the STAR TUBETM that receives an injection end 38 of a fuel
injector, a cap, as shown enlarged in Fig. 2a, or other closure 40 may be
configured with an opening 4~1 that may be tapered to match a taper of fuel
~5
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injection end 38. Positioned in. cap 40 around injection end 38 are a
plurality
(9 shown) of openings O, which may be sized to handle air flow through the
STAR TUBETM for a particular engine. While a plurality of openings O are
disclosed, other sizes and types of openings axe also workable. For instance,
as shown in Fig. 2b, a single, annular opening 37 around end 38 of fuel
injector 12 may be provided, possibly out to the inner diameter of the STAR
TUBETM, or a smaller number of openings O may be constructed in end B of
the STAR TUBETM. Also as described, the openings may also be omitted, with
the injector and cap sealed to form a closed end to the STAR TUBETM. In this
to embodiment, the volume of the interior of the STAR TUBETM forms a gas and
fuel vapor reservoir that provides a motive flow responsive to suction
developed by a piston on its intake stroke, and the lighter components of fuel
flashing into vapor. In some instances, the STAR TUBETM diameter may be
enlarged, or the length extended, so as to create a larger gas/vapor reservoir
within the volume of the STAR,TUBETM.
In the example of Fig. 2, a STAR TUBE'1'M constructed for use in a
350 cubic inch displacement engine is shown. In a popular, conventional
version of this engine, there are four fuel injectors mounted in ports
positioned directly in the airflow of a throttle body of the engine. As
modified
2o with STAR TUBEsTM, the fuel injectors and STAR TUBEsTM are mounted and
supported by brackets (schematically illustrated by dashed lines) so that
there
is a STAR TUBETM mounted between each fuel injector and fuel injector port.
It may be that the embodiments of the STAR TUBESTM that utilize a portion of
the induction air flow as carrier gas perform better when mounted in a
throttle body due to the fact that the low-pressure pulses developed by intake
strokes of the pistons are attenuated because of the distance between the
intake valves and the throttle body. In contrast, a closed STAR TUBETM and
associated fuel metering valve located proximate an intake valve may function
well because the low-pressure pulse associated with an opening intake valve
so is more strongly felt by the liquid fuel/gas in the STAR TUBETM.
One STAR TUBETM that has been found to work well for the
aforementioned 350 cubic inch engine is shown in Fig. 2. In this
embodiment, the tube portion 42 is about 1.5 inches outside diameter and
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about 1 inch inside diameter and about three to four inches long. Cap 40 is
provided with a plurality (9 shown) of openings O around a periphery of the
cap, these openings O each being about 0.187 inch in diameter. A central
opening 44 in cap 40 is about 0.5 inch in diameter to receive the fuel
injector
end 38. In the instance where there is simply an opening in cap 40 around
end 38 of the fuel injector, forming an annular opening, or where cap 40 is
omitted entirely, the injector body would be supported exterior of the STAR
TUBETM so that end 38 is generally coaxially positioned with respect to the
STAR TUBETM.
The region of the tube portion 42 immediately adjacent cap 40,
which may be about 0.250 inches thick, may be tapered on an interior side
over about a 0.5 inch length of the tube portion as shown in order to provide
a
clearance for openings O, and to provide a feeder region for fuel spray from
the injector. Additionally, this taper somewhat compresses air flowing
through openings O, thus advantageously speeding up velocity of air flowing
through the STAR TUBETM. Alternately, the STAR TUBETM may be
constructed of thinner material. As such, the spray of fuel from the fuel
injector is initially introduced into the STAR TUBETM along with a flow of
air.
The flow of air and fuel droplet spray then encounters a plurality (S shown)
of
2o turbulence-inducing devices, namely serially arranged Star Spin and Shear
Plates 46 spaced about 0.75 inch from one another, with the closest star plate
to the injector being spaced about 0.75 inch from the interior transition of
the
taper. As described, this volume, and to some extent the volumes between
the Star Spin and Shear plates, forms a reservoir (in the absence of openings
O) wherein air and fuel vapor in the STAR TUBETM constitute carrier gas.
The Star 'plates may be mounted in the tube as by an interference fit
between edges of each plate and an interior of a tube, by lips or supports
constructed along an interior surface of the tube that the plates rest on, by
bonding the plates within the tube, securing by fasteners, or any other
obvious means for securing the plates within the tube, as represented by
blocks 48 in Fig. 2. Further, in the event a plate inadvertently loosens
within
a STAR TUBETM, an end of the STAR TUBETM closest to the irdtake manifold
ports or throttle body port may be slightly narrowed or otherwise constructed
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so that the Star Spin and Shear plate is riot drawn into the intake manifold.
The Star Spin and Shear plates 46 each have a plurality of types of
openings (Fig. 3), these openings being' a central opening 50 of about 0.5
inches in diameter and a plurality, in this instance 6, of narrowing spoke-
like
slits or openings 52 communicating with and radially extending from central
opening 50. As shown in Fig. 3, openings 52 may be initially relatively wide
at
central opening 50, and converge with distance from central opening 50 to a
point 54 radially positioned at approximately 50 percent to 85 percent or so
of
a diameter of the plates 46. A ratio of the diameter of plate 46 with respect
to
to central opening 50 may be about 3 to 1, but a range of about 1.5 to 1 or so
up
to about 5 to 1 has been discovered to be workable.
As a feature of the invention, Figs. 3 - 5 also illustrate a downwardly
depending vane 56 positioned on edges of each of openings 52. Vanes 56 may
be downwardly angled, as shown in Figs. 4 and 5, at about from a few degrees
to almost 90 degrees from a plane of the plate. However, in one contemplated
embodiment that works well, a vane angle of about 40 degrees is used. Vanes
56, in conjunction with an opposed edge 58 of openings 52, serve to provide
edges 60 (Fig. 5) that create turbulence when the airflow passes through a
respective opening 52. This turbulence shears and breaks up larger fuel
2o droplets into smaller droplets as the flow passes through successive star
plates 46 until a desired droplet sire of about 50 microns is reached. In
addition, since all vanes 56 are oriented to direct airflow in the same
direction, a net spin of~the aerosol mix through the STAR TUBETM is provided
(clockwise in Fig. 3), causing larger fuel droplets to drift outward due to
centrifugal force toward a perimeter of the STAR TUBETM, where they are
forced to pass through a narrower portion of slits 52 where turbulence is
greater. Here, this greater turbulence developed by the narrower regions of
slits 52, in combination with sharp or abrupt edges 60, causes the larger fuel
droplets to be broken up into smaller droplets. As such, smaller fuel droplets
so that are not as greatly affected by centrifugal force are prone to pass
through
portions of openings 52 closer to, or through central opening 50.
In addition, it has been found that the vanes may be angled either
upward or downward, with approximately equal performance with respect to
is
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breaking up larger droplets into smaller droplets. Here, while the rotation
imparted by downwardly extending vanes causes axial spin of fuel/ air mixture
through the STAR TUBETM, upwardly extending vanes also creates spin
through the STAR TUBETM, in addition to the aforementioned shearing action
around edges of openings 52.
While a Star Spin and Shear plate is disclosed, other configurations
of plates with openings therein have been tested and have been found to
work, albeit to a lesser extent but to an extent which may be practical. For
instance, in one test the Star Spin and Shear plates were replaced with
1o conventional flat washers having only a central opening. In thus example,
spin of the airflow was eliminated while providing relatively sharp or abrupt
edges around central openings in the washers, these edges developing
turbulence in the airflow. This embodiment worked about 40% as well as the
Star Spin and Shear plates having vanes and radially extending slits. In
another test, the Star Spin and Shear plates were replaced with TENON-type
quick-connect nuts, urhich are configured similarly to the Star plates. These
worked about 70-80 percent as well as the Star Spin and Shear plates. From
this, it should be apparent that openings of any configuration in the plates
may be used. This would include star-shaped openings, rectangular
openings, square openings, or any other opening configuration. In addition,
these openings may be alternated between successive plates so that a first
plate may have one particularly configured opening and the next plate may
have a differently configured opening, and so forth. In addition, it has been
found that other types of washers and washer-like devices, such as star-type
lock washers, which also have a similar configuration to a Star plate, work
well. Another device that has been found to work to some extent is a disk or
plate similar to a star-type lock washer except lacking a central opening. In
this latter embodiment, fuel restriction was found to be a problem, but wider,
outwardly extending radial slots or openings that terminate at a periphery of
the plate may improve performance.
While 6 spoke-like slits 52 are shown in a Star Spin and Shear plate,
more or fewer of these slits may be employed, such as about three or more.
Likewise, while 5 star plates are shown and have been found to be optimal,
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fewer or more of these plates may be used, such as from about 1 or 2 to 7 or
so. Also, the STAR TUBEsTM and Star plates may be scaled as necessary
depending on displacement of the engine and number of fuel injector/STAR
TUBETM assemblies per cylinder. As stated, more plates and smaller openings
and slits produce smaller droplets, with fewer plates and larger openings and
slits producing larger droplets. Also, a greater rate of flow produces smaller
droplets, while a slower rate of flow produces larger droplets.
As a primary function of a fuel injector is to provide a selected
amount of fuel as determined by an engine controller, the fuel injector simply
serves as a variable fuel metering valve responsive to the engine controller.
As
such, it may be possible to replace the fuel injector with a simple metering
valve that provides the required amount of fuel, and generally as a spray or
stream, to a STAR TUBETM responsive to a signal from the engine controller,
with the STAR TUBETM breaking up the fuel into droplets of the predetermined
~5 size of about 50 microns and less.
It has been found that in the instance where a carrier gas is used,
the carrier gas passing through all the STAR TUBEsTM of an engine may be up
to a maximum of about five percent or so of the total induction airflow
through the throttle body and intake manifold. In any Star Tube system, the
2o process of breaking up the larger droplets may further be assisted or
regulated by additives in the fuel to limit droplet breakup beyond a selected
smallest size, such as 1-10 microns or so. Here, the additive may be selected
so as to increase surface tension in the fuel droplets so that the smallest
droplets of the fuel fog do not break up into yet smaller droplets. For
25 instance, the addition of a small amount of heavier oil or fuel oil to
gasoline,
or addition of a small amount of glycerin or castor oil to alcohol, may
increase
surface tension or reduce volatility of the fuel so as to facilitate small
droplet
formation arid minimize vapor formation.
As stated, when lighter fuels, such as gasoline, are initially sprayed
3o into a STAR TUBETM from a fuel injector or similar nozzle, more volatile
components of the fuel are vaporized instantly due to being released from
pressure in the fuel pail or feel system, which may be about 30 PSI or so, and
exposed to the vacuum pulse in the intake manifold adjacent an intake valve.
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This flashing into vapor saturates and cools . the environment in the STAR
TUBETM so that further evaporation of the remaining heavier-component fuel
droplets is prevented. Further, when drawn into the induction airflow, the
volume of lighter-component fuel vapor containing the heavier-component fuel
droplets forms a gas and vapor bolus of cool, hydrocarbon fuel-saturated air
that stabilizes the heavier-component fuel droplets and prevents them from
evaporating as they are drawn into a combustion chamber. Thus, in
embodiments closed to an external source of carrier gas, a fuel charge for
each intake stroke is made up of fuel droplets (50 microns and less) of the
1o heavier-component fuel suspended in air partially saturated with cooled
lighter-component fuel vapor. ~ Such separation ~of the fuel into lighter-
component vapor and heavier-component, size limited droplets may
contribute to more efficient and faster burning of the fuel by causing faster
propagation of the flame front through the fuel vapor/droplet/air mixture.
Several test engines have been adapted with Applicant's invention in
order to test feasibility, practicality and workability of the STAR TUBEsTM.
For
instance, one such engine was adapted as described above, and performed on
a dynamometer as follows:
Engine:
2o A Chevrolet 350 CID engine bored out 0.030 to provide about 355 CID and a
Compression Ratio of about 10.6:1.
Total runs done: more than 160.
4 STAR TUBEsTM: (Step Diffuser plates enhanced by Star spin)
mounted in a throttle body,
Six Star spoked openings, base to base: 3 / 4 in.
Peak anti-detonation effect in this engine was found with 5 to 7 Star plates.
With more than 7~ plates, power began to drop, probably because of fuel
restriction. With 3 plates, the effect was still about 80% of what it was with
5
plates. In this engine;
so Star plate OD: 15/ 16 in.
Tube ID: 13/ 16 in.
Tube OD: 1 1/4 in.
Tube length about four inches
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Smaller sized Star plates and tubes produced effectbut with
still an a
proportional reduction in engine Sizing of Star plates may
power. the
therefore be a function of air-flow akin to enginesize)through
(almost the
engine. Considerable latitude appears to exist, but larger area Star plates
work better with larger displacement engines, and vice versa. As a general
rule, the STAR TUBEsTM work well when they receive about 5% of the total
induction airflow through the throttle body. The opening or openings in cap
12 around the fuel injector tip are generally sized to allow little
restriction of
carrier gas flow through the tube. Typically, engine runs were from 5000 rpm
1o down to 2500 rpm, with data readings taken by conventional engine
monitoring equipment.
Engine measurements were taken at every 250 rpm from between
1500 rpm up to about 4500 rpm. Critical detonation data typically comes in
between 3000 and 3500 rpm. Peak torque typically comes in between 3000
and 4000 rpm. Spark advance was set for best torque (without detonation, if
any). With C-12 (108 octane racing fuel used to establish a baseline), there
was never any detonation regardless of the amount of spark advance (this did
not exceed 36 degrees). Using a gasoline with an octane rating of about 80,
peak torque with the STAR TUBEsTM was typically at about 30 degrees spark
2o advance with no knock. Peak torque was always equal to or better with STAR
TUBESTM and 80 octane gasoline than peak torque with C-12 and
conventional fuel injectors. The lesser spark advance used to obtain peak
torque with the STAR TUBESTM is indicative that the 80 octane fuel fog burns
faster than the C-12. Further, it has been found that utilizing STAR TUBEsTM
and 80 octane gasoline, with the spark advance set for peak torque at 28-30
degrees spark advance, exhaust gases are cooler, indicating that more
available power is converted to mechanical energy, and not wasted as heat.
In an aviation context; a ROTORWAYTM helicopter engine in a
helicopter was modified with STAR TUBEsTM and extensively tested. In this
so embodiment of the STAR TUBEsTM, the tubes were similar to the ones used in
the ChevroletTM engine as described, except were closed to any external
carrier
gas. The gasoline feed region of the STAR TUBETM serves as a gas/vapor
reservoir. The ROTORWAYTM engine is a fuel-injected aviation engine rated at
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145 horsepower, with a fuel injector for each cylinder of the engine, each
fuel
injector injection tip mounted in a fuel injector port located just upstream a
respective intake valve. The fuel injectors were removed, and a STAR TUBETM
mounted in each fuel injector port. The fuel injector was then mounted at the
other end of the STAR TUBETM, and as stated, closed to any external source of
carrier gas so that there was a small air reservoir approximately 3~4" - 1" or
so
between the fuel injector tip and the first Star plate. In full power
dynamometer tests, the ROTORWAY engine equipped with STAR TUBEsTM
produced over 200 horsepower, as opposed to 145 horsepower for a full power
1o test of the conventional version of the engine. In a 30 minute hover test,
the
ROTORWAY helicopter equipped with STAR TUBEsTM used slightly under
three gallons of gasoline at a 1 / 3 power throttle setting, as compared to
the
same helicopter without STAR TUBEsTM which used four gallons of gasoline at
a 2/3 power throttle setting in the same 30 minute hover test. Olearly, the
embodiment of STAR TUBEsTM closed to any external carrier gas, at least with
respect to the ROTORWAY engine, provides about 25 percent increase in
power and efficiency.
The STAR TUBETM of the instant invention may also work with
certain Diesel or Diesel-type engines wherein the fuel is ignited by
2o compression. In this instance, and referring to Fig. 6, a cut-away,
diagrammatic vie'v of a Diesel cylinder and combustion chamber 60 are
shown. In this particular type of Diesel engine, a swirl chamber 62 is
conventionally provided in a head portion 64 of the combustion chamber, and
a swirl cutout 66 is conventionally provided in a piston 68. A passageway 70
communicates between swirl chamber 62 and combustion chamber 72. A
fuel injector 74 is mounted so as to inject fuel into swirl chamber 62, with a
STAR TUBETM 76 of the present invention mounted in passageway 70 so as to
receive fuel from injector 74 and convey a fuel fog to combustion chamber 72.
It is to be noted that the STAR TUBETM 76 is sized so as not to completely
fill
3o passageway 70, thus allowing some of the combustion air to bypass STAR
TUBETM 76. As stated, the dimensions of the Star plates and STAR TUBEsTM
for a Diesel engine may be adjusted to obtain a different particle size if a
particle size other than less than 50 microns is found to be optimal.
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Operation of the embodiment of Fig. 6 is as follows. During the
compression stroke, essentially all of the combustion air is compressed into
the swirl chamber. At the appropriate time, which is typically 2 degrees or so
before top dead center for a Diesel engine, fuel is injected into the STAR
TUBETM. At the beginning of the fuel injection, it is believed a small
combustion burn occurs in the STAR TUBETM, depleting the tube of oxygen
and allowing the remainder of the fuel to be sprayed into the STAR TUBETM.
The remainder of the fuel is processed by the STAR TUBETM as described
above, with some of the gas from the swirl chamber passing through the STAR
to TUBETM and the fuel fog ejected from the STAR TUBETM and burned in the air
bypassing the STAR TUBETM via passageway 70. When cold, the engine may
be started by means of a conventional glow plug 80 positioned below STAR
TUBETM 76.
In yet other embodiments that may be particularly applicable to
i5 gasoline or other sparked ignition 'engines, and referring to Fig. 7 by way
of
example, a combined fuel injector or fuel nozzle and STAR TUBE form an
integral assembly 200 that is more compact in length than a sealed fuel
injector and STAR. TUBETM combined as described above. This is
accomplished by moving the fuel nozzle or other fuel-supplying orifice 212 up
2o into assembly 200 to a point near a fuel rail 230. A STAR TUBETM 208 is
mounted to receive, at one end, fuel from the fuel port or nozzle 212, with
the
other end of the STAR TUBETM configured to be mountable into a fuel injector
port 238 of an intake manifold or throttle body 236. The assembly 200 is
conventionally sealed at fuel rail 230 and at port to 38, as by O-rings 209.
25 Significantly, to provide a motive flow of gas through the STAR TUBE, an
air/vapor reservoir 216 may be provided and which is sealably coupled to a
top of STAR TUBETM 208, with nozzle or tube 212 extending as shown
therethrough to a point near an entrance of the STAR TUBETM. In other
embodiments, tube 212 and the reservoir 216 may be shortened or omitted
3o entirely in order to shorten the assembly 200, with fuel provided directly
from
the metering valve into the STAR TUBETM. Such an embodiment may be used
in conjunction with heating the fuel to develop vapor that serves as a carrier
gas, as will be further explained.
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The assembly 200 is provided with an outer hollow housing 202
having a port 232, which as stated sealably communicates with fuel rail 230,
with the combined fuel valve and STAR TUBETM assembly 204 mounted in
housing 202. Housing 202 may be constructed to internally and rigidly
support assembly 204 at an interface region 206, although other internal
mounting arrangements may be implemented, as should be apparent from
Applicant's disclosure to one skilled in the art. An armature assembly 218 is
provided between housing 202 and assembly 204, and is provided with a
magnet portion 220 that reacts against a magnetic field developed by solenoid
222. Thus, armature assembly 218 is raised and lowered responsive to
control current applied to solenoid 222. Also attached to an upper portion
223 of armature 218 is a needle portion 224 of a needle valve, which is
mounted so as to release a flow of fuel through an entrance 226 of nozzle 212
when the armature is raised. A spring 228 biases armature 218 downward,
pressing needle 224 against a needle valve seat 229 at entrance 226 until the
armature is lifted by an energizing current pulse provided to solenoid 222:
Vertical or other guides (not shown) may be incorporated on armature 218
and on interior surfaces of housing 202 so that needle 224 is maintained in a
precise position with respect to seat 229 as the armature is actuated up and
2o down. As stated, fuel rail 230 provides fuel to the interior of housing 202
via
opening 232, from which pressurized fuel flows to opening 226. For reducing
hydrostatic resistance as the armature is moved up and down, the armature
may be provided with openings; or be constructed as a cage-like structure, as
should be apparent from Applicant's disclosure to those skilled in the art.
.25 Further, the skirt of the armature may be shortened so as to extend barely
over the reservoir, reducing its mass. In this instance, the coil 222 would be
appropriately positioned. As should be apparent from Applicant's disclosure,
the armature and fuel valve may take many forms, the primary feature being
that of a fuel metering valve constructed in conjunction with a STAR TUBETM,
3o with or without an air reservoir, and all as a single, integral, compact
unit.
In operation, and as stated, pulses of appropriately poled current
flow, which may be on the order of about 1 - 15 milliseconds or so, depending
on the fuel demand to the engine, are applied to solenoid 222. Responsive to
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these pulses, armature 218 is lifted against the bias of spring 228, releasing
fuel through opening 226 for a duration approximately equivalent to the
duration of each pulse. Just before or concurrently with each pulse, an
intake valve in the engine opens and an associated piston begins downward
travel of the intake stroke, creating a temporary vacuum pulse in the intake
manifold. This temporary vacuum pulse causes air in air reservoir 216 (when
provided) to rush downward through the STAR TUBETM and out port 238. In
addition, such a temporary vacuurri pulse in combination with pressure in the
fuel rail assists in vaporizing lighter components of the fuel, which develops
1o more carrier gas and vapor and cools and saturates air in the STAR TUBETM
as described above. Fuel droplets from nozzle 212 are carried along with the
rush of air along with the lighter, vaporized components of the fuel from
reservoir 126 and processed as described above by Star plates 210. After the
intake valve closes, the partial vacuum pulse is eliminated and air fills the
Star TUBETM. Thus, in this embodiment, an external supply of gas or air need
not be provided to the STAR TUBETM, and the entire assembly 200 may be
constructed in a more compact form, possibly a short as the length of a
conventional fuel injector. In these embodiments that do not use an external
caxrier gas, it may be that after a short period of operation, and
particularly at
2o higher RFM's of the engine, reservoir 216 becomes filled with fuel vapor
that
may simply oscillate back and forth on each stroke of the engine, with all the
fuel vapor never really clearing the reservoir. In this instance, the lighter-
component, fuel saturated environment in the reservoir assists in preventing
further evaporation of the heavier-component fuel droplets. Of course, as the
lighter fuel components flash into vapor when released from pressure in the
fuel rail, the newly formed fuel vapor displaces any fuel vapor remaining in
the STAR TUBETM along with the heavier-component droplets.
Figs. 7a and 7b each show an integral device similar to that of Fig. 7,
except that in Fig. 7a the reservoir is narrower and in-line vvith the STAR
3o TUBE. In Fig. 7b, there is only a very small or no reservoir, the STAR
TUBETM
being directly below a fuel valve. This embodiment is functionally the same as
was tested in the ROTORWAYTM helicopter. In addition to the designs
described herein, it should be apparent from Applicant's disclosure to one
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skilled in the art that the combined fuel nozzle/STAR TUBETM may take many
forms. For example, a fuel-dispensing tube may extend generally
perpendicular into the STAR TUBETM, or at an angle over the top of the STAR
TUBETM, to inject liquid fuel at a point just over the first Star Plate. The
closed gas/vapor reservoir over the top of the STAR TUBETM would provide
carrier gas and vapor as described on the intake stroke, or the fuel may be
heated to flash some of the fuel into a vapor to provide carrier gas. Also, a
fuel injector nozzh may be mounted adjacent a top of the STAR TUBETM to
dispense fuel into a top of the STAR TUBETM and in a direction generally
1o perpendicular to the STAR TUBETM. In this embodiment, the fuel injector
portion may be fabricated alongside the STAR TUBETM so the assembly would
be wider and shorter than the embodiments of Figs. 7, 7a and 7b. Of course,
in these embodiments a tube or nozzle may also be extended to direct fuel
approximately coaxially into the STAR TUBETM.
Also shown in Fig. 7b, and by Way of example, is a small heater or
heating element 205 located or mounted to an exterior upper region of
assembly 204 so as to heat liquid fuel just prior to the fuel passing through
the needle valve. This or a similar embodiment may be used in cold
environments where less fuel flashes into vapor that otherwise would reduce
carrier gas flow through the STAR TUBETM. Here, such an embodiment may
be useful in an aviation context where a heater such as heater 205 may be
used continuously at a colder, higher altitude, and switched OFF at lower,
warmer altitudes. Of course such a heater may be used in a ground vehicle
travelling between cold and warm climates. Also, such a heater may initially
be used when starting a cold engine in order to develop more carrier
gas/vapor, which in turn causes more flow through the STAR TUBETM that
breaks cold liquid fuel into smaller droplets that are easier to ignite. As
noted
above, when cold engines are started, relatively large amounts of pollution
are
produced due to poor combustion properties of cold fuel in a cold engine.
Additionally, such heating of the fuel may be beneficial in engines fueled by
heavier fuels that do not readily flash into vapor, such as jet fuel, in order
to
cause more of the fuel to flash into vapor or otherwise cause the fuel to be
easier to ignite. In this embodiment, the fuel may be heated continuously, or
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CA 02519355 2005-09-15
WO 2004/094810 PCT/US2004/002186
heated only as needed to effect faster burning of fuel with little or no
pollutant
generation.
While a heater is shown within the assembly 200 of Fig. 7b, it should
be apparent from Applicant's disclosure to one skilled in the art that several
embodiments that include heating of the fuel may be implemented. For
instance, the entire assembly 200 may be insulated and heated as by
wrapping an external heating element around the assembly, or. the fuel may
be heated in the fuel rail or in a connecting region between the fuel rail and
assembly 200. Alternately, the larger volume of fuel within assembly 200 may
to be heated, as by providing a heating element near solenoid 222, or a
heating
element may be incorporated in solenoid 222. In addition, tube 212 may be
heated to flash a portion of the fuel into vapor to develop carrier gas, or
the
STAR TUBETM portion itself may be heated to flash a portion of the fuel to
vapor. Alternately, as shown by dashed lines in Fig. ?b, some or all the fuel
may be sprayed directly from the fuel metering valve directly onto a heated
screen, perforated plate or similar heater 207 to evaporate a portion of the
fuel to develop carrier gas just prior to processing a remainder of the liquid
fuel through the STAR TUBETM.
Other, more volatile fuels than gasoline may also be used in
2o conjunction with a STAR TUBETM system. For example, . cryogenic fuels such
as liquefied propa~.ze or liquefied natural gas, and possibly hydrogen, may be
used. Here, a step down liquid-to-liquid regulator may be used so that the
output pressure of the fuel may be regulated to about 40 psi or so, with the
fuel lines carrying this lower pressure being thermally insulated so that the
lower-pressure fuel is maintained in a chilled and liquid state. Any vapor
developed in the fuel lines may be returned to the tank. In this instance, a
standard fuel injector or similar metering valve may be used to dispense the
chilled liquid fuel. Operation would be the same as with gasoline, with a
portion of the liquid fuel flashing into vapor, saturating the environment of
so the STAR TUBETM with hydrocarbon gas and further cooling the fog of
droplets, stabilizing the droplets and retarding further evaporation of the
droplets until they are burned.
As should be apparent from Applicant's disclosure, there are many
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WO 2004/094810 PCT/US2004/002186
ways in which an integral unit containing a STAR TUBETM and fuel injector or
fuel valve, or other droplet generator such as those earlier described, may be
configured, either with or without a discrete air/gas reservoir. Also, the
size
of the reservoir and distance between the Star plates may be adjusted to a set
size and distance so as to take advantage of a particular RPM range of an
engine, or may be adjustable "on the fly" so as to be adjustable throughout an
engine's RPM range in order to assist or facilitate broadening a power band of
. , . _. ,
the engine. Such variations or adjustrizent ~of the reservoir size and/or
distance between the Star plates may be in accordance with harii~.orlics or
to resonance of the air column within the star tube,~arid possibly in
conjunction
With resonance 'of the reservoir; to make gas flow through the star tube more
efficient, enhance fuel flow or to increase or decrease gas pressure spikes in
the STAR TUBETM and reservoir (where used). Such tuning would generally
be similar to tuning of exhaust systems in order to make air flow through the
~ 5 engine more efficient. .
Having thus described ,my invention and the manner of its use, it
should be apparent to those skilled in the arts to which my invention pertains
that incidental changes may, be made thereto that fairly fall within the scope
of the following appended claims, wherein I claim:
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