Note: Descriptions are shown in the official language in which they were submitted.
5--
The present invention is directed toward burner
assemblies, or lighters or igni~ors as they are ~ometimes
known, for large ~team generating units, ~ ., boilers.
Each assembly provides an oil gun for the combus~ion of fuel
oil in urnaces where water is heated to generate steam heat
and power in boilers. Such boilers are typically found on
land for power generation or heat production. Much smaller
boiler~ are used on marine vessels. The burner is ired by
oil which has been atomized and mixed with air or other
compressible medium.
15~CR5ROUN~ ART
Typically, the furnace walls are lined with water
tubes, pipes through which water is circulatedf heated and
converted into steam and collected in a large drum usually
above the furnace. In order to heat large quantities of
water, multiple burner assemblies can be employed which are
inserted through at least one wall of the furnace or at each
of the corners, or roof mounted, depending upon the designs
of the manu~acturer. The burners are at least positioned so
i ~hat combustion occurs at or near the center of the ~urnace
interior ~o that the heat is more evenly spread.
The oil fuel is atomized by each gun and enters
the furnace as a sprayO There it is initially ignited by an
ignitor probe which provides a shor~ succession of electric
discharges from its tip to cause initial combustion 9f the
oil which thereafter continues a~ the oil is fed. In
addition to the air which may be used to atomize the oil,
other air is supplied through an air or wind box and is
circulated within a larger conduit through which the oil gun
is centered. This air enters the ~urnace concentrically
with the atomizer tip of the oil gun to provide a source of
air for proper combustion. Additionally~ other air can be
fed into the furnace from sources other than that of the
atomizer tip. ~7
3~
The ~ir i8 intended to insure complete as w211 as
controlled combustion of the oil. Controlled combustion
means that the flame should begin at or near the atomiæer
tip and extend to the center of the furnace interior in a
large, bushy shape. ~hen the combustion is not properly
controlled, the flame may not beg;n until some distance from
the tip and then it may burn with a narrow shape appearing
more as a jet or torch. ~hen this occurs, some quantity of
the fuel is not combus~ed and it will either all to the
furnace floor or be carried through the furnace and become
deposited on various heat transfer surfaces. The latter
creates the potential for catastrophic air heater fires and
the like. As to the combusted ~uan~ity, it may provide a
flame beyond the center of the furnace which provides uneven
heating and in extreme occasions it could focus on several
of the tubes on the far wall which can lead to premature
failure. In addition, for a specified heat input it is
known that a narrow, pencil-like 1ame cannot provide the
same amoun~ of energy as a large bushy flameO
To overcome many of these deficiencies in 1ame
control, multiple burner assemblies are provided as
previously noted~ Also, the supply of air, which is fed at
controllable rates, is adjusted to provide more or less
( ~uantity within the furnace to bring the flame back to the
~5 atomizer tip and also to spread out its shape. Fans provide
the combustion air and it is the circulation of air around
the oil gun that is critical for proper 1ame development
and stability. Existing burner assemblies have used various
combinations of holes and air swirling devices in an attempt
to create a structured turbulence that encompasses the oil
spray and penetrates it to provide sufficient air at each
oil particle in the expectation that complete and maximum
combustion will occur.
Despite the years that burner assemblies have been
3S employed and the many design variations, flame adjustment or
~ontrol can take much time or fuel is wasted and in some
instances, maximum combustion efficiency is never obtained.
More complex assemblies may increase selective combustion
efficlency componen~ bu~ these are m~re labor intensive and
require longer down time of the furnace when work is
required on the oil gun which mus~ be periodically removed~
disassembled and cleaned or replaced.
~5~
It is therefore an object of the present invention
to provide a burner assembly or furnace$ and the like
wherein fuel is combusted to generate heat and ~team.
ld It is another object of the present invention to
provide a burner assembly that provides more complete
combustion of the fuel.
It is another object of the present invention to
provide a burner assembly that provides a controlled,
improved flame pattern.
It is yet another object of the present invention
to provide a burner assembly ~hat is more efficient and is
less costly to service and maintain.
~ t is yet another object of the present invention
to provide an improved atomizer tip fox burner assemblies.
It is still another object of the present inven-
tion to provide a method whereby combustion eficiency of
li~uid fuel(s) and air mixtures is improved~
It is a fur~her object of the present inven~ion to
~5 provide a method for combustion whereby flame pattern is
controlled and improved.
These and other objects, together with the advan~
tages thereof over known burner assemblies, which shall
become apparent from the ~pecification which follows, are
accomplished by the invention as hereinafter described and
claimed.
In general, a burner assembly for the combustion
of liquid fuels in furnaces and the like comprises fuel gun
means for creating a mixture of combustible fuel and an
atomiziny medium and injecting a stream of the mixture into
the interior of the furnaceî housing means carrying the fuel
gun means, attachable to the furnace, so that the com-
bustible fuel mixture is delivered to the interior of ~he
~urnace for combustion and ~upplying a first flow of air
into the furnace to encompass the inje~ted f~lel mf.xture
therein, holding tube means for supplying a second 10w of
air into the furnace lnterior separate from the first flow
of air andy swirler means having a plurality of blades
interposed within the housing means so that the fir~t flow
moves around and through he blades to impart a rotation to
the first flow of air to break up the stream of fuel mix-
ture.
The present invention also provides a related
burner assembly ~or the combustion of liquid fuels in
furnaces and the like comprises fuel gun means for creating
a mixture of combustible fuel and an atomizing medium and
injecting a stream of the mixture into the interior of the
furnace; housing means supporting the fuel gun means,
attachable to the furnace, so that the combustible fuel
mixture is delivered to the interior of the furnace for
combustion and supplying a first flow of air into the
furnace ~o encompass the injected fuel mixture therein and,
swirler means having a plurality of blades interposed within
the housing means so that the first flow moves around and
through the blades to impart a rotation to the first flow of
air to break up the stream of fuel mixture.
The present invention also provides a method for
supplying fuel and air mixtures to furnaces and the like
through a burner assembly which results in increased combus-
tion effi~iency. Such a method comprises the steps of
injecting a mixture o fuel and an atomizing medium from a
fuel gun into the interior of the furnace; feeding a first
flow of air through the burner assembly and into the furnace
interior; interrupting the first flow of air so that a
portion thereof moves axially forward into the furnace
interior while another portion is imparted a rotation and,
encompassing the mixture with the first flow of air as the
mixture enters the furnace, whereby both portions of the
first flow of air break up the mixture within the furnace.
An improved atomizer tip for mixing a separate
supply of air with a separate supply of fuel is also
53~L
provided. ~t comprl e~ firR~ and ~econd plurallties of
narrow air pas6ageway~ extending through the ~tomizer tip
for the movement of air there~hrough, and a plurality of
narrow oil passageway~ for the movement of fuel. The oil
passageways commun~cate with the fir~t plurality of air
passageways wlthin the atomizer t~p whereby ~he fuel becomes
atomized by the air as it is ejected from the fir~t
plurality of air passageways and becomes mixed wi~h the air
ejected from the ~econd plurality of air pa~sageways upon
ejeetion from the fir~t plurali~y of air passageways.
An improved method for atomizing liquid fuel is
also provided and includes the steps of forcing a volume of
( air through fir~t and ~econd pluralities of nsrrow air
passageways provided in an a~omizer ~ip and extending
therethro~gh; forcing a volume of fuel through a plurality
of narrow oil passa~eways which communicate with ~he first
plurality of air passageways; ejecting a mixture of atomized
fuel and air from the first plurali~y of air passageways
and, dispersing air from the second plurality of air
passageways into the mixture of atomized fuel and air.
~ F DESCRIPTION QF T~_nBa~I~Ç~
Fig, 1 is an overall perspective ~iew of a furnace
( for ~team ~eneration depicting a configuration of three
burner assemblies with uel and air supplies;
Fig. ~ is an enlarged ~ide elevation, partially ln-
section~ and taken substantially along line 2-2 of Fig. 1,
depicting one embodiment of burner assembly aceording to the
present invention;
Fig. 3 is a further enlarged frontal elevation, taken
substantially along line 3-3 of Fig. 2, depicting the air swirler
from the burner assembly of Fig. 2;
Fig. 4 is a developed view, taken substantially
along the line 4-4 of Fig. 3, of a ~egmen~ of the swirler
component depicting a plurality of blades thereof;
~ig, 5 is a diagrammatic view of he air and of
the fuel mixture emanating from the tip of a burner assembly
of the present invention;
~ 8 ~3~
Fig, 6 ls an enlarged side elevation, partially in
8ection, deplcting a second embodiment of burner assembly
according to ~he present inVen~on;
Fig. 7 is an enlarged frontal elevation, taken
substantially along line 7-7 of Fig. 6 t depicting the air swirler
from the burner assembly of Fig. 6;
Fig. 8 is an enlarged ~ide elevation, partially ln
~ection, ~epicting a third embodiment of bu~ner assembly
according to the present inven~ion;
Fig. 9 is a further enlarged frontal elevation, taken
substantially along line 9-9 of Fig. 8, depicting the twin air
s~irlers fxom the burner assembly of Fig. 7;
Fig. 10 is an enlarged ~ide elevation, p~rtially
in section, depicting a foùrth embodiment o burner assembly
according to the presen~ invention;
Fig~ ll is a cross-sectional ~iew depicting an
existing atomizer tip;
Fig. 12 is a front elevation of the atomizer tip
of Fig. 11;
Fig. 13 is a cross-sectional view, ~aken substan-
tially along line 13-13 of ~ig. 14~ depicting an improved
atomizer tip;
FigO 14 is a front elevation of the improved
( atomizer tip;
Figs. 15A-15C depict flame pat~erns u~ually
obtained with existing burner assemblies and Fig. 15D
depicts a properly controlled flame pattern obtained with
any of the burner assemblies of the present invention.
~
Four embodiments of burner assemblies are provided
by the present invention. Variations among the assemblies
allow or the design most particularly suited for a yiven
type of furnace to be ~mployed. Wi~h reference to FigO 1~ a
trio of burner assemblies, generally re~erred to by the
numeral 10 is depicted mounted on and through a wall 11 of a
furnace 12. The furnace interior 13 is lined along its
walls with a plurality of tubes 14 through which water is
circulated~ heated and converted to steam.
It will be appreciated ~hat ~ig. 1 i-~ only illus-
trative of furnaces ln general having wa~er/s~eam tubes and
that for clarity and discussion the top of the furnace has
not been shown, nor has any steam drum or means for cir-
culating steam and returning water been presented. The
present invention is not directed toward furnaces or the
generation of s~eam, per se, only improved burner assemblies
that can be employed therewith. Thus~ it is to be under-
stood that practice of the present invention is not limitedto the use of three burner assemblies or any other
plurality; nor is the use of one precluded. Moreover, the
assemblies can be mounted in a side wall, as depicted, or a~
the corners of the furnac~, as is known.
Oil or other liquid fuel is supplied from a tank
15 and is pumped through pipes 16 to an oil gun described
hereinbelow. Compressed air or steam is also fed to the
fuel from an air compressor or proper steam source 18 and
pipes 19. Inasmuch as it is known to mix air or steam with
liquid fuel in the atomizer of a burner assembly, reference
to the term air in conjunction with the fuel gun shall be
unders~ood to mean air or steam or for that matter, any
other compressible atomi~ing medium unless otherwise stated.
The atomizing medium, such as steam, helium or the like,
~5 need not support combustion as the primary function is to
atomize the liquid fuel.
Wind box 20, is also provided which serves as a
manifold to supply large quantities of air via fan 21 ~o
each o the burner assemblies and, ln turn, the furnace
interior for combustion. Each of the burner assemblies is
suitably affixed to a port in the furnace wall sucb as by
bolts and flanges (not shown) which permit disassembly and
re-installation or replacement of the assembly~ Before
describing each o~ the burner assemblies in greater detail,
it is to be understood that any of the four burner assem-
blies embodied herein could be employed with furnace 12 or
one of similar design for burning oil and other liquid
fu~ls.
-8-
With reference ~o Fig. 2, ~he first burner
a~embly 10 ~ deplcted. It comprises a uel or oil gun 25,
housing means 26 by which the oil gun 25 1~ ~upported and a
first supply of air B is supplied to an air swirler 28. The
S housin~ member 26 ~5 a large metal tube having a diameter of
between elght and 16 inche (20 to 40 Cm)r It is ~o be
understood that burner assembly 10 i~ not neces6arily
limited by the~e dimensiQns, however~ ~ousing member 26
passes through the furnace wall 11 and is open a end 29 to
the furnace in~erior, At the opposi~e end 30, a flange 31
is provided to which a closure plate 32 i~ removably
affixed~ An opening 33 in the ~ide of the housing receives
a leg 34 which is connected to the air bo~ 20 and receives a
large volume of air. The leg 3~ is generally not removable
from the housing 26~ Moreover, the leg c~n be affixed at an
angle to the tube 26 or perpendicularly, as shown.
It can be seen in Fig. 2 that a first volume of
air is fed into the housing 26 ~hrou~h the leg 34 to exit
out the end 29 directly into the furnace interior. Rather
than deliver a forward moving blast of air, the swirler 28
is provided in the opening. The ~wirler, which comprises a
cylindrical hub 35 and a plurality of blades 35, is
removably affi~ed to the end 38 of a holding tube 3g with a
clamping device 40. The blades 36 extend radially outwardly
toward the inner wall 41 of,hou~ing 26.
A narrow axial ~pace ~2 i8 provided between the
outermost edge 43 o~ each blade 36 and inner ~all 41. This
space is important for it allows some of the air moving
through housing 26 to travel around the swirler 28 and
continue i~ an axial flow. The diameter of e~isting
~wirlers has been considerably less than the inner diameter
of housing member 26 and an outer ~nnular ring encompasses
the blade edges 43. Thus, s;gnificant amounts of the
axially moving air passing throu~h hou~ing 26 ~low around
the swirler. By increasing the diameter o the swirler 28
to substantially that of ~he housing 26, greater control
over the flame pattern has resulted as well as improved
combustion efficiency, Elimination of the outer ring and
provision of the space 42 allows BOme of the air to flow
around the swirler which also contributes to grea~er control
and efficiency.
The holding tube 39 passes through a bore 45 in
the closure plate 32. A ~uitable fastening device 46 can be
employed to maintain tube 39 in position. One or more
spiders 48 can also be employed to support tube 39~ An
opening 49 in the side of tube 39 is provided with a flange
50 to which a ~eparate air line 51 is connected. As seen in
the drawings, the air line 51 can readily be positioned
within leg 34. It can receive air from the wind box 20 or
from a separate air su~ply, such as the fan 52 and line 53
shown in Fig. 1.
The oil gun 25 is a conventional element and
1~ includes an air or steam line 55 which passes concentrically
~ithin an oil line 56. Both the air and fuel pass
separately through the gun until reaching the atomi~er tip
58 where mixing takes place by atomization of the oil which
is injected under pressure as a stream into the furnace
interior 13~ It is also possible to pass the oil~line
concentrically within the air line and then employ a dis-
tributor plug or similar element to direct the oil flow to
the outside and the air flow inside just prior to reaching
the atomizer tip~ Although the present invention can employ
~5 an improved atomizer tip, to be described hereinbelow,
generally speaking, ~he oil gun 25 havin~ a standard
atomizer 58 can be utilized with the burner assembly lOr
The oil gun 25 is centered within the holding tube
39 by one or more spiders 60. A baffle plate 61 is welded
to the pipe 56 to form a seal within holding tube 39 so that
the flow of air from the line 51 will traval along the oil
gun to be released within the atomized fuel mixture.
With reference to Figs~ 3 and 4, the swirler 28 is
depicted in greater detail. Each blade 36 is curved to
present a concave rear face 65 and a convex front face 66
which is directed toward the furnace interior. Each blade
also presents a trailing edge 68 toward the furnace interior
and a leading edge 69 which is confined within the housing
-10
g~
member 26. The blades are each affixed to the hub 35 in an
overlapping configuration so that the ~railing edge 68 of
one blade overlaps ~he leading edge S9 of the next blade
In this manner, air passing through the ~ousing
member 26 cannot pass straight through any of the blades but
first contacts ~he rear faces ~5. As ~he air moves around
the leading edge 69 of a blade, its path is next impeded by
the trailing edge 68 of an adjacent blade. Because the
blades are each curved, the air is given a curved slotted
passageway 70 through which to flow which imparts a rota-
tional movement to the air as it enters the furnace~ In
order to ease the movement of the air into the swirler, each
of the leading edges 69 is essentially parallel to the flow
of air, as depicted in Fig. 4. Although Fig. 4 has been
developed from Fig. 3~ it is characteristic of the other
swirlers to be discussed hereinafter.
At this point, rPference is drawn to Fig. 5 which
depicts, diagrammatically the various flow patterns. First,
the oil and air mixture is seen exiting the atomizer 58
~ where it fans outwardly to form an expanding cone A The
large volume of air B passing through the housing member 26
contacts the swirler 28 and encompasses the atomized fuel
cone A, in a separate cone Bo The air in cone B rotates in
the direction of ~he arrows C and helps to disperse the fuel
cone A with air. Simultaneously, a narrow~ ~orward moving
volume of air is delivered through the cylindrical hub 35 at
D, where it also passes directly into the cone A, as it just
begins to emerge and expand, helping to slice it open and
expand it further as the swirler air, cone B slices into it.
All of this results first in a heavy concentration of air
directly at the atomizer tip Second, rather than move
forwardly, which would confine cone A, the air components B
and D penetrate the fuel cone, dispersing the atomized fuel
particles with air ~o maximize combustion efficiency.
With reference next to Figs. 6 and 7, a second
embodiment shall be described. The burner assembly,
indicated generally by the numeral 75 comprises a fuel or
oil gun 76, housing means 78, which supports oil gun 76 and
provides a supply of air, and an air ~wirler 79. The
housing member 78 is again a metal tube having a diameter
between four to ~ix 1nches ~10 to 12.5 cm). It is to be
understood that burner as embly 75 is not necessarily
limited by these dimensions. Neverthele~s, the burner
assembly 75 is much smaller than the assembly 10 and is
employed with smaller urnaces or those requiring less input
or where the application cannot accommodate larger burners.
The housing member 7~ also passes through the
urnace wall 11 and i6 open at end 80 to the furnace
interior~ At the opposite end 81, a flange 82 is provided
to which a closure plate 83 is removably affixed. An
opening 84 in the side of the housing receives a leg 85,
which is connected perpendicularly or at an angle, and
which receives air from the wind box 20 as discussed herein-
above.
The oil gun 76 is again a conventional element,
including an air line 86, oil line 88 and atomizer tip 89.
Inasmuch as these elements are the same as those previously
~0 described in conjunction with the oil gun 25 of Fig. 2,
further detail is not necessary. The oil gun 76 is centered
within the housing member 78 by one or more spiders 90. A
baffle plate 91 is welded to the oil line 88 to form a seal
( behind the opening 84 so that the flow of air f ed through
the leg 85 will travel along the oil gun to be released with
the atomized fuel mixture.
As the air moves through the housing member, it
contacts the swirler 79 which is mounted directly to the
atomi~er tip capnut 92 affixed to the end 93 of the gun 760
Swirler 79 includes a plurality o blades 94 radiating
outwardly therefrom. Each blade 94 presents a convex front
face 95, a concave rear face 96 and overlapping trail;ng and
leading e~ges, 98 and 99 respectively. The outermost edges
100 terminate a short distance from the inn~r wall 101 of
the housing member 78 to provide an axial space 102 so that
the air passing through member 78 moves through the blades
94 as well ~s around the edges 100. Again, the design of
the swirler essentially fills the housing member 78 and no
-12-
outer ring is employed.
In thiR embodlment, tbe size of the oil gun and
overall burner assembly ls ~uch that the only additional air
needed can be supplied through the housing member and thus,
a separate supply is not also provided~ Forward moving air
does pass through the axial space 102 in sufficient volume
to help mix with the fuel cone in addition to the rotating
volume of air that passes through the swirler 79~
With reference next to Figs. 8 and 9, a third
embodiment shall be described, The burner assembly~
indicated generally by the numeral 110, comprises a fuel or
oil gun 111, housing means 112 by which the oil gun 111 is
supported and a first supply of air is ~upplied and an air
swirler 113. The housing member 112 is a large metal pipe
having a diameter of between 12 and 24 inches ~30 to 60 cm).
It is to be understood that the burner assembly 110 is not
necessarily limited by these dimensions. ~ousing member 112
passes through the furnace wall 11 and is open at end 114 to
the furnace interior~ At the opposite end 115l a flange 116
is provided to which a closure plate 118 is removably
affixed. An opening 120 in the side of the housing receives
a leg 121 which is connected to the air bo~ 20 and receives
a large volume of air~ The leg 121 is affixed to the
housing 11~ perpendicularly, as shown, or at an angleO
It can be seen in Fig. 8 that a firs volume of
air is fed into the housing 112 through the leg 121 to exit
out the end 114 directly into the ~urnace interiorO Rather
than deliver a forward moving blast of air, the swirler 113
is provided in the openingO The swirler~ ~hich comprises a
plurality of blades 123, is affixed to the end 124 of a
holding tube 125. The blades 123 extend radially outwardly
toward the inner wall 126 of housing 112.
A narrow axial space 128 is provided between the
outermost edge 129 of each blade 123 and inner wall 126 to
allow some of ~he air moving through housing 112 to flow
around the swirler 113c Again, use of a larger diameter
swirler, the elimination o~ an outer ring around the blades
and provision of the space 128 has resulted in greater
-13-
~ 3~
control over the fl~me pat~ern and efflciency of the combus-
t~on.
The holding ~ube 125 pafi es through a bore 130 in
the clo~ure plate 118. ~ ~uitable fastening device 131 can
be employed ~o maintain tube 125 ~n pos~tlonO An opening
132 in the side of tube 125 i5 provided with a flange 133 ~o
which a ~eparate a~r line 134 is connected. OnP or more
spiders 135 oan be employed to ~upport the tube 125 within
housing member 112. ~8 seen in the drawing, the air line
13~ is positioned within leg 121 so that it too receives air
from the wind box 20, which eliminates the need for a
separate air supply, although one could be employed such as
the fan 52 shown in Fig. 1, discus~ed hereinaboYe~
Because of the làrge ~izes invo~ved, the holding
tube 125 can also carry a swirler 136. Thus, the burner
assembly 110 combines elem~nts o~ the burner assemblies 10
and 75. The swirler 136 is mounted directly to the atomizer
tip capnut 138 affixed to the end 139 of the oil gun 111.
Swirler 136 includes a plurality of blades 140 radiating
outwardly therefroma With reference to Fig. 9, each blade
140 presents a convex front face 141, a concave rear face
142 and overlapping trailing and leading edges; 143 and 144,
respectively. The outermos edges 145 ter~inate a ~hort
distance from the inner wall 146 of the holding tube 125 to
~5 provide an axial space 148 0 that the air pas~ing through
holding tube 125 moves through ~he blades 140 as well as
around the ed~es 145.
In similar fashion, the blades 123 of ~wirler 113
are curved to present a convex front face 149, a concave
rear face 15~ and overlapping trailing and leading edges,
151 and 152 respectively. The orientation of the blades 123
of swirler~ll3 ifi ~uch that the air movement is counter~
clockwise, ~s depicted by the arrow E, while the blades 140
of the inner swirler 136 are oriented to move the air in the
opposite direction or clockwise, as depicted by the arrow ~O
The counter-rotating air flows and axial flow around
~wirlers 113 and 136 effects very efficient mixing of the
air and the fuel cone in large burners.
~14-
~ 9~
Once again, ~he oil gun 111 is a conven~ional
element, ~ncluding an air line 153, oil line 154 and
atomizer tip 155. Inasmuch as these el~ments are ~he ~ame
as ~hose previou~ly described in conjunction wi~h the oil
gun 25 o Fiy. 2, further detall is not necessary. The oil
gun 111 is cen~ered within the holding ~ube 125 by one or
more spiders 156 and is clamped to the baffle plate 158 by
clamp collar lS9. The baffle plate 158 is welded to the
tube 125 to form a ~eal behind ~he opening 132 so ~ha~ the
flow of air fed through the leg 134 will travel along the
oil gun to be released with the atomized fuel mixtur~,
With ref erence to Fig. 10, a ourth buxner
assembly 160 is depicted. It comprises a fuel or oil gun
161, housing means 162 by which the oil gun 161 is supported
and a first supply of air is supplied and an air swirler
163. The housing member 162 has a diameter of between eight
to 16 inches (20 to 40 cm). It is to be understood once
again that burner assembly 160 is not limited by these
dimensions. ~ousing member 162 passes through the furnace
~0 wall 11 and is open at end 164 to the furnace interior. At
the opposite end 165, a flange 16S is provided to which the
closure plate 16~ is removably affixed. An opening 169 in
the side of the housing receives a leg 170 which is
connected to the wind box 20 and receives a large volume of
~5 air. The leg 170 is affixed to the housing 162 perpen-
dicularly or at an angle.
It can be seen in Fig. 10 that a first volume of
air is fed into the housing 162 through the leg 170 to exit
out the end 16~ directly into the furnace interior. Rather
than deliver a forward moving blast of air, the fiwirler 163
is provided in the opening. The swirler, which comprises a
cylindrical hub 171 and a plurality of blades 172~ is
affixed to the end 173 of a holding tube 174 with a clamping
device 175. The blades 172 extend radially outwardly toward
the inner wall 176 of housing 162.
A narrow axial space 178 is provided between the
outermost edge 179 of each blade 172 and inner wall 176 ~o
allow some of the air moving through housing 162 ~o flow
-15-
~ g~3~
around the sw~rler 163. Again; use of a larger diameter
~wirler, the elimination of an outer ring around ~he blades
and provision of the space ~78 has resulted ln greater
control over the ~lame pattern and efficiency of the combus-
tion. The swirler is es~entially identical ~o ~he ~wirlerspreviously described, each blade having a con~ex face 180, a
concave rear 181 and ~railing and leading edges 182 and 183.
~ence, a separate view has not been presented.
The holding tube 174 passes through a bore 185 in
the closure plate 168. A suitable fastening device 186 can
be employed to maintain tube 174 in position and one or more
spiders 188 can be used for support. A plurality of axial
ports 189 are provided in the side of tube 174 so that it
too receives air from the air box 20, which eliminates the
need for a separate air supply.
The oil gun 161 is a conventional element and
includes an air line 190 which passes concentrically within
an oil line 191. Both the air and fuel pass separately
through the gun until reaching the atomizer tip 192 where
mixing takes place by atomization of the oil which is
injected under pressure as a stream into the ~urnace
interior 13. Although the present invention can employ an
improved atomizer tip described hereinbelow, generally
speaking~ the oil gun 161 having a standard atomizer 1~2 can
be utilized with the burner assembl~ 10.
The oil gun 161 is cen~ered within the holding
tube 174 by one or more spiders 193. A baf1e plate 194 can
be welded to the oll line 191 to form a seal within holding
tube 174 so that the flow of air through the porks 18~ will
travel along the oil gun to be released within the atomized
fuel mixture.
To help impart a rotational movement to the air
passing through the housing member 162 before it contacts
the swirler 163, a plurality of helical lands 195 are formed
at the time of forging or they may be welded to the inner
wall 176. Of course, they can also be provided in ~he
housing members of the other burner assemblies although not
depicted in the drawings.
-16-
With reference now to Figs. 11 and 12, a conven-
tional atomizer tip 200 such as ~ips ~8, ~9, 155 an~ 192
noted hereinabove is de~cribed in greater detall. The ~ip
200 provides a base flange 201 which is gripped by the ring
202 of a capnut 203 threadably aff ixed to the oil line 204
A central flow of air is fed through line 205 to enter a
central ehamber 206, A plurality of angled passageways 208
pass outwardly ~rom the chamber 206 to the ~ace 209 of tip
200. Simult~neously, oil or other fuel is fed through the
passageway 210, outside of the air line where it enters a
plurality of radially inwardly directed passageways 211
which terminate in the air passageways 208. As fuel exits
passageways 211, it is immediately sheared by the air in
passageways 208 forming atomized particles which exit with
the air. Although the design may be alterPd to provide oil
centrally and air in the outside line, with the use of a
distributor plug to direct the oil to the exterior, the tip
200 is customary in providing atomized fuel.
The present invention ~lso provides an improved
atomizer tip 215, depicted in Figs~ 13 and 14~ It provides
a base flange 216, gripped by the ring 218 o~ a capnut 219
threadably affixed to ~he oil line 2200 A central flow of
air is fed through line 221 to enter a central chamber 222.
A plurality of angled passageways 223 and 224 pass outwardly
from the chamber 222 to the face 225 of tip 2150 Simul-
~aneously, oil or other fuel is fed through the passageway
226 r outside of the air line where it enters a plurality of
radially inwardly directed passageways 228 which terminate
in the air passageways 223. As fuel exits passageways 228,
i~ is immediately sheared by the air in passageways 223
forming atomized particles which exit with the air. Addi-
tionally, more air is fed directly at the atomizer tip ~ia
passageways 224 which do not intercommunicate with any of
the oil passageways. Air actually is the atomiæing medium
for atomizer tip 215 because that portion fed through
passageways 224 is employed to support combustion of the
fuel,
Thus, it should be clear that the present
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invention succeeds in providing ~everal improved burner
assemblies, each one employing structure that delivers
usable air in the immediate vicinity of the atomized stream
of fuel par~icles. U8 of ~he foregoing burner assemblies
facilitates the method of the present lnvention which
supplies air to fuel and air mixtures ~o provide increased
combustion efficiency. As noted hereinabove, such a me~hod
is practiced by injecting a mix~ure of fuel and an atomized
medium from a fuel gun, e~a~, 25 into the lnterior 13 of a
furnace, ~eeding a ~irst flow o~ air B through the burner
assembly and into the furnace interior, intarrupting the
first flow of air so that portions thereof move axially
~orward into the furnace interior while another portion is
imparted a rotation and, encompassing the mixture with the
1~ first flow of air as the mixture enters the furnace whereby
both portions of the first flow of air break up the mixture
within the furnace.
Finally, with respect to Figs. 15A-15D, the effect
of the method of the present invention has been depicted by
a comparison of flame patterns existing heretofore with a
flame pattern (Fig~ 15D~ from a burner assembly described
herein.
FigsO 15A-lSC each depict a fuel gun 230 passing
hrough a furnace wall 231 and one of three typical flame
patterns that result from a lack of controlled combustion.
In Fig. 15A, the flame 232 is narrow and drawn out,
resembling a torch. This results from high internal air
velocity, limited air and little to no mixing of air and
fuel. ~ence, combustion is poor. There is no burning
occurring at areas 233 and the core 234 shows incomplete
combustion.
In Fig. 15B, the flame 235 is lazy and smokey. It
is caused by low to no internal air velocity, limited air
and no mixing. Again, combustion is generally poor. No
burning occurs at region 236 beyond the atomizer tip.
In Fig. 15C, the flame 238 extends out in long t
narrow fingers of partially burned oil, typically caused by
limited or no air~ incorrect velocities and no mixing.
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~ 3q~
Again, eombustion ls poor and a smokey flame results. The
centers 239 are poor burningO
In Fig, 15D, ~he flame 235 has been properly
controlled and combustion is complete. It wlll be noted
that the flame is large and bushy and that combu~tion begins
essentially at the atomizer tip of the burner assembly 10,
or the like described herein. ~ir veloclties and amounts
are correct and the air core and air envelopes are forced to
mix with the atomized oil.
Thus~ it should be clear to those skilled in ~he
art the manner in which the various ~urner assemblies
described herein are constructed, assembled and used. It
should also be clear that the atomizer ~ip 215 is novel and
may be utilized with any of the burner assemblies of this
invention as well as in existing assemblies.
Based upon the foregoing disclosure, it should now
be apparent that the use of the assemblies described herein
will carry QUt the objects set forth hereinabove. It should
also be apparent to those skilled in the art that the burner
assemblies of the subject invention can readily be utilized
in conjunction with various types of furnaces and that the
most basic assembly 75 can be modified with the provision of
a holding tube to route a second volume of air; an addi-
tional swirler can be added and the helical lands discussed
in conjunction with assembly 160 can be employed with any of
the assembliesO
Although approximate si~es have been disclosed for
each of the burner assemblies, none of the ranges should be
interpreted as limiting. As noted hereinabove, there may
exist situations where a smaller or larger burner assembly
may be interchanged for a previous assembly such as where
more or less heat input is desired, size constraints are
present or the like. Thus, it is believed that those
skilled in the art can determine the design of burner
assembly that will be most usable from the total specifica-
tion disclosure provided herein~
It is, therefore, to be understood that any
variations evident fall within the scope of the claimed
~LX81~9~L
invention and thus, ~he selection of specific component
element~ can be determined wi~hout departing from the spirit
of th invention herein dl~closed and described. ~oreover,
the scope of the invention 6hall lnclude all modifications
and variations that may fall within the ~cope of ~he
attached claims.
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