Injector for turbine engines

An injector for turbine engines which includes a shaped injector core fitted with an eccentric spinner inlet communicating with a cylindrical, annular fuel spinner chamber and a preheater or evaporator for preheating and vaporizing fuel, wherein the vaporized fuel is eccentrically injected into the fuel spinner chamber to effect a spinning fuel sequence around a fuel guidance pin extending through the center of the fuel spinner chamber. Compressed air from the turbine compressors flows through the primary nozzle of an air guidance nozzle surrounding the injector core into a shaped secondary nozzle, where the air mixes with the spinning fuel at a selected air flow angle to facilitate thorough mixing of the fuel and air as the combustible mixture is channeled into the annular turbine combustor. The unique spinning component applied to the preheated, vaporized fuel and manner of introducing the compressed air into the spinning fuel using multiple, spaced injectors and corresponding air guidance nozzles effects exceptionally good air-fuel mixing and facilitates increased turbine operating efficiency and reduction of NOX emissions in the turbine exhaust gases.

BACKGROUND OF THE INVENTION 
Field of the Invention 
This invention relates to techniques for improving the efficiency of 
turbine engines and reduction of noxious components in the turbine exhaust 
gases. More particularly, the invention relates to a new and improved 
injector for turbine engines, which injector is characterized in a 
preferred embodiment by a shaped injector core fitted with an eccentric 
spinner inlet nozzle communicating with a cylindrical, annular spinner 
chamber, and a preheater or evaporator for preheating fuel and injecting 
the vaporized fuel at a selected temperature into the fuel spinner chamber 
through the eccentrically-positioned fuel spinner nozzle or opening, to 
effect a spinning fuel sequence around a fuel guidance pin extending 
through the fuel spinner chamber. Compressed air from the turbine 
compressors flows through the primary nozzle of an air guidance nozzle 
enclosing each injector core, into a shaped secondary nozzle and mixes 
with the spinning fuel in a flow focus zone at a selected mixing air flow 
angle to facilitate thorough and homogeneous mixing of the fuel as it is 
channeled into the annular turbine combustor. The unique spinning 
component applied to the preheated, vaporized fuel by the several 
injectors and the manner of introducing air into the spinning fuel from 
the respective secondary nozzles of the air guidance nozzles effects 
surprisingly good air-fuel mixing and facilitates excellent engine 
operating efficiency and reduction of undesirable "NOX" emissions in the 
turbine exhaust gases. 
One of the problems which is arising in ever-increasing significance is 
that of noxious, air-polluting components in the exhaust gases of turbine 
engines, including jet airplane engines and such equipment as stationary 
engines, typically turbine-operated generators, pumps and refrigeration 
turbine engines, as well as other engines and systems utilizing fuel 
injecting equipment. Solutions to this problem have included both wet and 
dry "NOX" control techniques which are well known to those skilled in the 
art, for the purpose of lowering undesirable turbine exhaust gas 
emissions. These emissions are hereinafter collectively referred to as NOX 
and include such ingredients such as carbon monoxide, nitrogen dioxide and 
the like, and in light of current pollution control standards, new and 
improved techniques for reducing these undesirable NOX emissions from 
turbine and other system exhaust gases is necessary. The conventional use 
of wet NOX and dry NOX techniques for achieving this result require 
heavier and more complex turbine equipment and are therefore 
counterproductive in many installations, including aircraft, as well as 
industrial and other applications. 
Accordingly, it is an object of this invention to provide a new and 
improved injector for turbine engines of various design, which injector 
not only increases the efficiency of the turbine engine with no increase 
in weight or complexity, but also reduces the emission of noxious, 
air-polluting components (NOX) from the turbine exhaust. 
Another object of this invention is to provide a new and improved injector 
for turbine engines and other engines and systems utilizing fuel injection 
equipment of various design, which injector is characterized by an 
injector core shaped to define an internal, curved, annular fuel spinner 
chamber having a centrally-projecting fuel guidance pin to facilitate 
spinning of fuel vapor introduced into the fuel spinner from an evaporator 
through an eccentrically-positioned spinner inlet, such that a spiral of 
spinning, preheated and vaporized fuel is created in the fuel spinner 
chamber and mixes with incoming compressed air from the turbine 
compressors or alternative air source at a selected mixing angle to effect 
a surprisingly complete and homogeneous mixture of air and fuel channeled 
to the turbine or engine combustor system. 
Still another object of this invention is to provide new and improved 
injectors for turbine engines, a selected design number of which injectors 
can be retrofitted to the annular combustion of existing turbine engines, 
as well as provided on new turbine engines and each injector including an 
air guidance nozzle enclosing a tapered injector core having an internal 
cylindrical, annular fuel spinner chamber defined around an 
outwardly-projecting fuel guidance pin having an enlarged end or tip, 
wherein preheated, vaporized fuel from a heat exchanger enters the fuel 
spinner chamber through an eccentrically-oriented spinner inlet to 
facilitate a spiral rotation of fuel in the annular fuel spinner chamber 
around the fuel guidance pin and from the fuel spinner chamber, guided by 
the fuel guidance pin tip, into an inwardly-directed, continuous, 
compressed air stream flowing through the corresponding air guidance 
nozzle, to create a significantly homogeneous, stoichiometric mixture of 
fuel and air prior to entrance of the combustible mixture into the annular 
turbine combustor. 
SUMMARY OF THE INVENTION 
These and other objects of the invention are provided in new and improved 
injectors for mounting in radially spaced relationship with respect to 
each other on the annular combustors of turbine engines, each of which 
injectors is characterized in a preferred embodiment by a shaped metal, 
ceramic or ceramic-coated injector core located in an air guidance nozzle, 
wherein compressed air from the turbine compressors is caused to flow 
between each injector core and the corresponding air guidance nozzle in 
inwardly-directed relationship to mix at a selected mixing angle with 
vaporized fuel introduced into a cylindrical fuel spinner chamber shaped 
in the injector core, through an eccentrically-located spinner inlet. The 
fuel is preheated as a vapor or vaporized in an evaporator or heat 
exchanger and is thus introduced along a selected chord of the circle 
defining the fuel spinner chamber and against the curved cylindrical wall 
of the fuel spinner chamber perpendicular to the longitudinal axis of the 
injector core, to impart a spinning and spiralling rotation of the fuel 
around a centrally-projecting fuel guidance pin that extends through the 
fuel spinner chamber, to mix with the air and create a significantly 
homogeneous, stoichiometric mixture of fuel and air, which is then 
delivered by the air stream to the annular combustor. This homogeneous 
mixing of preheated and vaporized fuel and air by the spiralling movement 
of the fuel into the air stream both increases the efficiency of the 
turbine and reduces the emission of NOX in the turbine exhaust gases.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring initially to FIGS. 1 and 2 of the drawings, a conventional 
turbine engine which is typical of the turbine engines in which the 
injectors of this invention may be mounted, is illustrated by reference 
numeral 1. The turbine engine 1 is characterized by an accessory drive 
assembly 2, which may be connected to various equipment such as a 
compressor, propeller or the like, for doing useful work. An air inlet 
assembly 3 is illustrated at the front of the turbine engine 1 and 
facilitates a flow of ambient air 4 into the turbine engine 1. The air 4 
passes through a compressor rotor 5, which is fitted with multiple, 
radially-extending rotor blades 5a, located in a compressor case 6. A 
compressor variable vane assembly 7 extends from the compressor case 6 
radially outwardly of the compressor rotor 5, as illustrated. A compressor 
diffuser 8 is provided on the inboard end of the compressor case 6 and a 
gas fuel manifold 9 encircles the combustor housing 35a, which encloses 
the annular combustor 35. Fuel lines 9a serve to channel fuel from the 
circular gas fuel manifold 9 to the conventional fuel injector 27, 
illustrated in FIG. 1, and identified by reference numeral 10 in FIG. 2, 
as a fuel injector of this invention. A bleed air valve 36, nozzle case 
37, gas producer turbine rotor 38, power turbine rotor 39, output drive 
shaft assembly 40, turbine exhaust diffuser 41 and exhaust collector 42 
complete the major components of the conventional, illustrative turbine 
engine 1 illustrated in FIGS. 1 and 2 of the drawings. 
Each one of the multiple fuel injectors 10 of this invention is more 
particularly illustrated in FIGS. 2-4 of the drawings and includes a 
cylindrical air-guidance nozzle 11, illustrated in FIGS. 3 and 4, having a 
cylindrical nozzle housing 17 which is symmetrical about a longitudinal 
axis 10a and terminates in a nozzle bevel 11a. The air-guidance nozzle 11 
includes a primary nozzle chamber 12, which receives compressed air from 
the compressor rotor 5 illustrated in FIGS. 1 and 2, and a secondary 
nozzle chamber 13, which channels and directs the compressed air from the 
primary nozzle chamber 12 into an annular, converging stream. The 
compressed air flow from the compressor rotor 5 is indicated by the arrows 
14 in the primary nozzle chamber 12 and by the arrows 23, as a mixing air 
flow, in the secondary nozzle chamber 13, as shown in FIG. 3. An injector 
core 15, having a cylindrical core wall 18, is disposed inside each 
cylindrical air guidance nozzle 11 and is also symmetrical about each 
longitudinal axis 10a, to define the secondary nozzle chamber 13. That 
portion of the injector core 15 which faces the incoming compressed air 
flow 14 is most preferably characterized by a core taper 16, shaped to 
channel the compressed air flow 14 around the injector core 15 and into 
the inwardly-directed secondary nozzle chamber 13 to define the mixing air 
flow 23, as illustrated in FIG. 3. A wall bevel 19 encircles the opposite 
end of the injector core 15 from the core taper 16 and parallels the 
nozzle bevel 11a of the air guidance nozzle 11 to further define the 
secondary nozzle 13. An internal, cylindrical, annular fuel spinner 
chamber 20 is provided in the injector core 15 opposite the core taper 16 
and receives an outwardly-extending, centrally-positioned fuel guidance 
pin 22, having an enlarged, flared end 22a, which is also symmetrical 
about the longitudinal axis 10a of each fuel injector 10. As further 
illustrated in FIGS. 3 and 4, a spinner inlet 21 is eccentrically provided 
in the curved wall of the cylindrical, annular injector core 15 and 
communicates with a fuel flow line 32, extending from an evaporator 28, 
hereinafter further described. Accordingly, fuel 32a which is injected 
into the annular space between the circular fuel spinner chamber 20 and 
the fuel guidance pin 22 from the eccentrically-oriented spinner inlet 21 
is injected along a chord of the circle defining the spinner chamber 20, 
directly against the curved wall of the cylindrical fuel spinner chamber 
20, thereby imparting a spinning component to the entering fuel, which has 
been preheated by heat exchange in the evaporator 28, as further 
hereinafter described. The spinning, vaporized and preheated fuel is 
identified by reference numeral 24 and the spinning fuel 24 spirals from 
the point of impingement in the spinner chamber 20, annularly around the 
fuel guidance pin 22 as illustrated in FIG. 4, to diffuse in the 
converging mixing air flow 23 flowing from the secondary nozzle chamber 13 
at the wall bevel 19 of the core wall 18, in a flow focus zone 25, as 
illustrated in FIG. 3 and as further hereinafter described. 
Referring again to FIGS. 3 and 4 of the drawings, the evaporator 28 is 
characterized by a first pass chamber 30 and a second pass chamber 30a, 
which direct the fuel 32a from the fuel inlet 31 through the evaporator 
28. Application of external heat 29 from the combustor 35 of the turbine 
engine 1 vaporizes the incoming fuel 32a if it is introduced as a liquid 
and preheats the vaporized fuel 32a to the point of entry into the 
cylindrical, annular fuel spinner chamber 20, through the spinner inlet 
21. Accordingly, the fuel 32a is preheated and vaporized when it exits the 
spinner inlet 21 and begins its spiralling annular flow as the spinning 
fuel 24 around the fuel guidance pin 22 and flared end 22a, into the 
mixing air flow 23, as heretofore described and illustrated. 
In operation, liquid or gaseous fuel 32a from a suitable storage tank (not 
illustrated) is introduced into the gas fuel manifold 9 illustrated in 
FIGS. 1 and 2 and is continuously pumped from the gas fuel manifold 9 
through the fuel lines 9a and into the fuel inlet 31 of the evaporator 28, 
illustrated in FIG. 3. Typical fuels which may be handled by the fuel 
injector 10 of this invention include methane, butane, propane, kerosene, 
alcohol, acetone, hydrogen and fluidized charcoal dust, in nonexclusive 
particular. If the fuel 32a is liquid when it enters the fuel inlet 31, it 
is quickly vaporized by application of the external heat 29 to the first 
pass chamber 30 and second pass chamber 30a. If gaseous fuel 32a is 
introduced into the fuel inlet 31, it is preheated to the desired 
injection temperature and in both cases, the fuel 32a exits as a preheated 
vapor at the spinner inlet 21 into the cylindrical, annular fuel spinner 
chamber 20. As illustrated in FIG. 4, the vaporized fuel 32a is directed 
longitudinally normal to the longitudinal axis 10a, along a chord of the 
circle defined by the circular fuel spinner chamber 20, against the curved 
wall of the fuel spinner chamber 20 and a spiralling spin having a fuel 
spinning velocity 24a, is thus imparted to the vaporized and preheated 
spinning fuel 24 as it rotates in the annular fuel spinner chamber 20, 
around the centrally-located and extending fuel guidance pin 22. The fuel 
spinning velocity 24a is a function of the speed of rotation of the 
vaporized fuel 32a and the diameter of the fuel spinner chamber 20. 
Accordingly, this spinning fuel 24 continuously spins toward the 
compressed mixing air flow 23, which continuously flows through the 
secondary nozzle chamber 13 at a selected mixing air flow angle 23a, 
measured with respect to the longitudinal axis 10a and is directed 
inwardly by the wall bevel 19 of the injector core 15 and the nozzle bevel 
11a of the air guidance nozzle 11. The mixing air flow angle 23 typically 
ranges from 0 degrees to about 90 degrees, depending upon application. The 
enlarged, flared tip or end 22a of the fuel guidance pin 22 directs the 
spinning fuel 24 into the mixing air flow 23 at a desired angle, 
preferably about 80 to 90 degrees, in a flow focus zone 25 and the 
spinning fuel 24 is quickly and efficiently diffused into the mixing air 
flow 23 to create an extremely homogeneous, highly combustible 
stoichiometric air/fuel mixture 26 in the flow focus zone 25, carried into 
the combustor inlet 33 of the combustor 35 by an excess of air in the 
mixing air flow 23, where it is ignited in conventional fashion. 
Accordingly, the rotational spin imparted to the preheated, vaporized, 
spinning fuel 24, coupled with the inwardly-directed compressed mixing air 
flow 23 to thoroughly and homogeneously mix the fuel and air, effects 
combustion which facilitates optimum turbine engine operating efficiency 
and minimum discharge of NOX in the exhaust gases 43 emitted from the 
exhaust collector 42 of the turbine engine 1. This elevation of turbine 
engine efficiency and reduction of NOX is therefore effected by more 
efficient mixing and burning of the fuel with an excess of air to produce 
thorough, stoichiometric burning and minimum emission of undesirable 
exhaust components such as carbon monoxide. 
It will be appreciated by those skilled in the art that the evaporator 28 
is illustrated in FIG. 3 as a double-pass heat exchanger for purposes of 
illustration only. Accordingly, a multiple-pass or even a single-pass heat 
exchanger may be used to characterize the evaporator 28, according to the 
knowledge of those skilled in the art, depending upon the temperature and 
character of the incoming fuel 32a entering the fuel inlet 31. For 
example, if the fuel 32a entering the fuel inlet 31 is liquid at a low 
temperature, appropriate external heat 29 will be applied to the 
evaporator 28 and the evaporator 28 must be designed with the appropriate 
number of pass chambers to effectuate entry of an appropriately evaporated 
and preheated fuel 32a at the spinner inlet 21 of the injector core 15. 
Under circumstances where the incoming fuel 32a is already vaporized and 
is at a higher temperature, minimum application of external heat 29 and a 
single pass such as a first pass chamber 30 only, may be necessary in the 
evaporator 28 to effect the desired injection temperature at the spinner 
inlet 21. Furthermore, it will be further understood that the size of the 
nozzle housing 17 and internal injector core 15, including the secondary 
nozzle chamber 13, as well as the dimensions of the fuel spinner chamber 
20 and fuel guidance spin 22 and flared end 23 and the other components of 
the fuel injector 10, may be varied and sized according to the dimensions 
of the turbine engine 1 in which the fuel injectors 10 are installed and 
used. Moreover, a selected number, typically 9 or 10, of fuel injectors 10 
may be installed in annular, circumferentially-spaced fashion around the 
annular combustor 35, according to design requirements for the respective 
turbine engine 1. Also, various types of pumps, accessory equipment and 
the like, may be used in connection with the fuel injectors 10 to supply 
either liquid or gaseous fuel to the evaporator 28, according to the 
knowledge of those skilled in the art. It will be further appreciated that 
the fuel injectors 10 may be retrofitted to existing turbine engines and 
installed in new turbine engines, as desired. 
The fuel injectors 10 of this invention may also be installed on burner 
systems and engines of non-turbine design. Since the application of one or 
more fuel injectors 10 operates to more efficiently disperse preheated, 
vaporized fuel into a directionally-controlled air stream, this 
application can be made to internal combustion engines, including 
reciprocating and rotary engines, as well as boiler systems and other 
systems requiring injection of fuel into a combustor or combustion chamber 
of various design and description. In any such engine or burner system, 
regardless of size, complexity or design, one or more of the injector 
cores and air guidance nozzles illustrated in FIGS. 2-4 may be mounted in 
the engine or burner at or near the combustion chamber. And a blower, or 
other air delivery system may be used to move air around the injector core 
through the air guidance nozzle, or, in the alternative, around the 
injector core in the angular relationship described above with respect to 
the longitudinal axis of the injector core, to create the desired 
stoichiometric mix of air and fuel for combustion and achieve the intents 
and purposes of the invention. 
While the preferred embodiments of the invention have been described above, 
it will be recognized and understood that various modifications may be 
made in the invention and the appended claims are intended to cover all 
such modifications which may fall within the spirit and scope of the 
invention.