Note: Descriptions are shown in the official language in which they were submitted.
DMR930225 2 1 7 5 9 3 4 PATENT
Docket No. 93A224
FUE~ BURNE R APPARAlUS ANlD I~OD
EMPLO~NG DIVERGENT FL~W NOIZZIE
TRouNn OF TITF INVI~ON
The present invention relates to a fuel burner apparatus and method for burning
a fuel in an oxidant. More particularly, the present invention relates to sucll a fuel burner
apparatus and method in which the oxidant is oxygen or oxygen erlriched air. The present
invention also relates to a nozzle that is capable of producing a flat, &vergent uniform
S flow of a fluid that is particularly suited for forming oxidant nozzles used ill a fuel burner
apparatus and method in accordance with the present invention.
Fuel burners are used in many industrial ~ ",~ in which a material to be
processed is melted, for example, glass, copper, alurninum, iron, and steel. In order to
10 maximize the he~t available from the fuel, oxy-fuel burners have evolved m which the
fuel is burned in oxygen or oxygen enriched air. These bumers generally produce flames
having a highly .~ r,l~ power output which carl in turn p}oduce hot spots in themelt. Typically, such bumers utilize high velocity oxidant and high mass flow rates of
fuel to produce the high power outputs. Taken together, the l / ~"r, ,~ r 1 heating tends
15 to evolve volatiles within the melt and the high velocities tend to ffntrain feed matffial to
the exhaust of the fumace. The ffntrained feed material and evolved volatiles can thffeby
be lost and pollute the ~I~u~ Qc or can form a deposit which ~, "" " ~ within the
furnace or exhaust heat recovffy systems used m I ; with furnaces.
A still furthff problffm in oxy-fuel bumQs is that the high ~C114J~l~UlC ~III~ iUII
of the fuel in oxygQn or oxygen fflriched air can produce polluting NOX.
DMR930225 2 1 7 5 9 3 4 PATENT
Docket No. 93A224
As will be discussed, the present invention provides a burner apparatus and method
that is less susceptible than prior art apparatus and m~thn~lnlngy to forming hot spots and
entraining feed particles within the flow of oxidant and fuel and furdler, is readily
adaptable to employ a NOX limiting form of .'1 " "1."~ .. ",
s
S~lMMARY OF TTlF. INV~ON
Ihe present invention provides a fuel bumff for burning fuel in an oxidant
fuel noz~le means and upper and lower noz~le means. The fuel noz~le means
10 p}oduces a fuel jet of outwardly divergent, fan-shaped .-nnfi~tinn whicll is adapted to
burn within the oxidant with an outwardly extending and divergent flame. The upper and
lower oxidant noz~le means are separate and distinct from one another and from the fuel
nozle means for producing upper and lower oxidant jets of outwardly divergent,
fan-shaped cnnfi~tinn located above and below the fuel jet, respectivel~ . The oxidant
lS jets have a lower velocity than the fuel jets such that the oxidant is aspirated into the fuel.
In another aspect of the present invention, the present invention provides a method
of burning fuel in an oxidant. In accordance with such method a fuel jet is produced of
outwardly divergent, fan-shaped ~nnfi~ tinn so that the fuel jet will burn within the
20 oxidant with an outv-~ardly extending and divergent flame. Upper and lower oxidant jets,
separate and distinct from one another and from the fuel jet are produced at locations
above and below the fuel jet, ~ iv~ly, and so as to have a lower velocity than the fuel
jet and thereby aspirate oxidant into the fuel.
In these forgorng aspects of the present invention, the fuel jet and ~xidant no~le
are outwardly divergent and fan-shaped to produce an outwardly extending flame burning
over a wide ar~ The wide area of ~ . has the advantage of permitting high
levels of heat input into a melt while ~ hot spots within the melt. The upper
and lower oxidant noz~:le means produce low velocity and therefore high pressure oxidant
jels which ~ tt ln Ptl~ctD~ a p~ ~t~hat t asptlalc tt e ~ to tt c t ~I
D~930225 2 1 7 5 9 3 4 PATENT
Docket No. 93A224
Since, however, the oxidant jets are of low velocity, they tend not to entrain feed particles
and thus serve to shield the fuel jet.
In still another aspect, the present invention provides a nozle for p~oducing a flat,
5 uniformly divergent flow of a fluid. Ihis nozzle is IJ~Li~uLuly well suited for selving as
the upper and lower oxidant noz~;le means. Ihe nozzle cornprises a body portion
including a ~ a~way~ Ihe ~ ,w~ has an outlet for d;~ g a duid flow and
an inlet to the ~ cway for introducing the fluid flow into the pa~a~way. A meansis provided for dividing the ~ a~v-a~ in a lengLhwise direction thereof and thus, the
10 flow of the fluid into a plurality of subflows having velocities of esserltially equal
magnitude and oriented so æ to gradually diverge in a transverse directiorl of the flow of
the fluid.
As stated ahove, the present invention can be adapted to reduce NOX forrnation.
15 In prior art oxy-fuel burners, Al",..~l,l,r.;,- nitrogen can react with oxygen to produce
thermal NOX. In addition, fuel radicals such as CIH can react with Al . "n~ , ;c nitrogen
to form prompt NOX. In this æpect of the present invention, r~lmh -ction of the fuel
occurs in two stages in order to reduce both thermal and prompt NOX formation. In a frrst
of the two stages of .~ ""~1"~1; ." of the fuel within the oxidant supplied by
20 the upper and lower oxidant jets is ~ ""~ Ihe blrrner further comprises
secondary upper and lower oxidant noz~le means separate and distinct from one another
and the upper and lower oxidant noz~le and fuel jet means. Ihe upper and lower oxidant
no~le and fuel jet means produce at leæt one pair of upper and lower secondary oxidant
jets of outwardly divergent, fan-shaped confi~-~tinn located above and b,low the upper
25 and lower oxidant jets, ~ iv~ly, for supplying sufficient amounts of oxidant to
complete ~nmhllctinn of t'ne fuel. Ihe ~nmhllctinn of the fuel is thereby r~ompleted in a
second of two stages of ~."~ It is to be noted that the sufficient amounts of
oxidant can either be just that required to romplete ~ or 't~ldliv~ly, can be
in ~ lu~ rl~ ;~ amounts. lhe ~ l" ~l~llo~y involved in this æpect of the present
30 invention comprises producirlg at leæt one pair of upper and lower secondary oxidant jets
of outwardly divergent, fan-shaped ~ ~" ,~ "~ at locations above and below the upper
~ =~
DMR930225 2 1 7 5 9 3 4 PA~ENT
Docket No. 93Aæ4
and lower oxidant jets"~liv~ly, so as to supply sufficient amounts of oxidant tocomplete .~""1",~1;.", of the fuel. Ihis staging of c~ mh lctirln has been found to lower
NOX formation.
S RRIFF DFA~(~RTT~ON OF TElF DF~AWIN('~
While the ~ ;r~ ,.,., collcludes with claims distinctly pointing out the subjectmatter that Applicant regards as his invention, it is believed tbat the invention will be
better understood when taken in connection with the awJ~ Jallyillg dra~ings in which:
Fig. I is a top plan view of a bumer in accordance with the present invention;
Fig. 2 is an elevational view of Fig. I,
Fig. 3 is a front elevational view of Fig. I;
Fig. 4A is a La~ll~,llL~y or a sectional view taken along line 4-4 of Fig. 3,
Fig. 4B is a La~ll~ll~y front elevational view of Fig. 4A;
Fig. 4C is a La~~ ~y~ cross-sectional view taken along line 4C of Fig. 4A;
Fig. 4D is a La~ll~ ~y~ cross-sectional view taken along line 4D of Fig. 4A;
Fig S is a L~ y side elevational view of another ernho;' of a burner
in accordance with the present invention employing oxidant staging and illustrated as
being set m a bumer block shown in section;
Fig. 6 is a front elevational view of Fig. 5.
Fig 7 is a top planar view of a nozzle employed in the bumer of Fig. 5.
. ~ ' 21 75934
D~930225 PAT~NT
Docket No. 93A224
Fig. 8 is an elevational view of a flame issuing forth from the burner of Fig. 5.
with the bumer block being drawn in section, ~,nd
Fig 9 is a top plancir view of Fig. 8.
DETA~T Fn DE!~CRITYriON
Wlth reference to Figs. 1, 2 and 3 a burner 10 in acoc,rd~,nce w~th the present
invention is illusttated. Burner 10 includes a fuel no~le 12, which, as will be described,
10 is designed to produce a fuel jet of outwc,rdly divergent, fcn-sha~ed c~-nfi~-riti in Such
a fuel jet will burn witbin suitably shal~ed oxidcnt jets with an outwc,rdly extending and
&vergent flame. Upper cnd lower oxidant nozzles 14 c,nd 16 are prcivided for producing
upper c,nd lower oxidc,nt jets of outwardly divergent, fc,n-shaped ~infi~iritinn located
above c,nd below the fuel jet. Ihe upper and IOWff oxidant jets of upper and lower
15 oxid-c,nt noz~les 14 and 16 have a lower velocity than the fuel jet. As a result, the oxidant
has a higher pressure than the fuel and the oxid~nt tends to æpirate into tlle fuel. Thus,
in the present invention, a high velocity fuel jet is shielded by low velocity oxidant jets
to help prevent the c~ llr~ll of feed that wou',d otherwise occur with burners of the
prior a~t. Burner 10 is specifically designed to burn natural gas in an oxidant of
20 essentially pure oxygen. It is understood that more generally the teachings set forth herein
have ~ y to different fuel gases such as hydrogen, ethane, propane, butane
acetylene and liquid fuels such as diesel fuel, heating oils, etc. Additionally the oxidant
can be oxygen enriched air.
As can be ~ ~L the fuel bums along the length of the flame and oxidc,nt
jets. As such, unburned fuel is heated and becomes ~JIV~ l v~ more buoyant along the
leng~th of the flame, ca~-,sing the flame to lick upwardly, away from the heat load. In
order to prevent this, lower oxidant noz~,e mear,s 16 can be designed such that the lower
oxidant jet has a higher mass flow rate t~,an that of the upper oxidant jet issuing from
upper oxidant noz~:le 14. I~is will result in the ~ ~ ", ~ ", of the fuel being primarily
in oxid~,nt supplied by the lower oxidant jet of higher mass flow rate with the "l~ lc~ ;ly
s
` 2 1 7593~
DMR930225 PA~T
Docket No. 93A224
more buoyant unburned fuel burning in the oxidant supplied by the upper oxidant jet. As
can be a~lulcc;~ an ~ IH~ of the present invention could be ~~ uc,~d witn
upper and lower oxidant noz~les producing oxidant jets of equal mass flow rates.
S Burner 10 is provided with a body 18 of elongated configuration l~aving top and
bottom walls 20 and 22 and side walls 24 and 26. Angled l~illru~ wl~ rnembers 28-34
are provided to stiffen body portion 18. Central fuel nozle 12 divides body portion 18
into upper and lower oxidant no~zles 14 and 16 which include upper and lower
pa~ d~wa,v~ 36 and 38 having outlets 40 and 42 and inlets 44 and 46.
A coupling assernbly 48 is cormected to the rear of body portion 18 to introduceoxidant into body portion 18 which in turn flows into inlets 44 and 46 of upper and lower
oxidant nozzles 14 and 16 and t'nereaPler, flows of outlets 40 and 42 thereof.
Fuel no~le 12 is supported within body 18 by upper and lower sets of vanes 50
and 52. Vanes 50 and 52 are connected to top and bottom walls 20 and 22 and to fuel
nozzle 12. Vanes 50 and 52 divide pa~ia~wa,ys 36 and 38 in the lengthwise direction
and therefore the flow of oxidant passing through upper and lower ~a~ay~Wdys 36 and
38 into a plurality of subflows. Vanes 50 and 52 are specifically designed such that the
velowties of the subflows will have an essentially equal magnitude and be oriented so as
to gradually diverge in a transverse direction to the flow of the oxidant. rnis is
effectuated by outwardly curving vanes 50 and 52 which are designed such that tangents
drawn at t'neir maximum cu~vatures all intersect at one location within the respective of
the ~ rway~ 40 and 42 of which vanes 50 and 52 subdivide. Although hidden, the
vanes extend rearwardly to the inlets 44 and 46 of upper and lower oxidant no~zles 14
and 16. A further advantage of the vaned upper and lower oxidant no7~les is ~at the
vanes allow for effective self cooling of burner 10 without extemal water cooling.
As stated previously, upper and lower oxidant nozles 14 and 16 are designed suchthat the lower oxidant jet will have a higher rnass flow rate than the upper ~xidant nozle
jet. Tnis is eflfected by a~ uu~ ly sizing the l~~ uldl, transverse woss-section of
. `~ 2 ~ 7593~ `
D~930225 PATENT
Docket No. 93A~24
upper and lower oxidant nozz;les to be in a ratio of cross-sectional areas srnaller than
unity. Ihe ratios are preferably in a range of between about 0.125 and about 0.5.
It is to be noted here that the design of oxidant nozzles 14 and 16 could be used
5 in other ~rrlj~tionc For instance, an oxidant nozzle could be designed in the rnanner
provided herein for use in creating a fiat, fan-shaped outwardly divergent field of oxidant
below a fuel jet or burner or in other words, for oxygen-lancing purposes~
~Ith reference to Figs. 4A through 4D, fuel nozzle 12 is preferably formed in two
10 sections 56 and 58. Fuel nozzle 12 is in the form therefore of a central body portion
having a chamber 60 and a plurality of ~ad~ y~ 62 of equal length, spa~ed apart from
one another, and gradually fanning out from chamber 60. Chamber 60 ~
between passages 62 and a fuel inlet 64 such that fuel flows from fuel inlet 64 and out
of passages 62. Passages 62 gr~dually fan out from cha~nber 60 so that the resultant fuel
15 jet v~ill fan out. Ihe equal length of passages 62 produce an equal pressure drop and
therefore equal velocity so that the fuel jet will fan out or horizontally diverge with liKle
decay. In the illustrated L.. 1 ~ 1.. Il the ratio of the average velocities of the fuel versus
oxidantis~ t~ly 13.5to IØ Aconduit66of,~~ ulal-transversecross-sectiorl
connects to a coupling 68 by means of a transition piece 70 ~vhich transitions from a
20 circular, transverse cross-section to a rectangular, transverse cross-section. If fuel nozzle
12 were to be employed to burn liquid fuels, suitable fuel nozzles (known ~vell in the art)
would have to be attached to passages 62.
~Ith reference now to Figs. 5, 6 and 7 an alternative L.l~;hl~ l of a fuel burner
25 appara~us of the present invention is illustrated. The illustrated L~ '- ' stages
oxidant into the fuel to reduce polluting NOX emissions while producing a flame paKern
illustrated in Figs. 8 and 9 which is horizontally divergent, fan-shaped and resistant to
decay along the length of the f~ame pattenL This is effected with the use of burner 10
such that fuel and oxidant is supplied from oxidant nozzles 14 and 16 in ~"l, ~l~ .;. l .: .. . ,~l . .c
30 amounts or in other words the oxidant supplied does not completely support c.... ,1...~l ;. ,, ~
of the fuel. Ihereafter, .~ ;-... of fuel is completed in upper and lower secondary
. ` 21 75934
D~930æS PAT~T
Docket No. 93A224
oxidant jets of outwardly divffgffnt, fan-shaped rA)nfigll~tir,n supplied at L~cations above
and below the Uppff and IOWff oxidant jets, ~ , by upper and IOWff secondary
oxidant no~les 72 and 74 set within a burnff block 75 along with burnff 10. Ihe
incomplete combustion occurs in a first stage of the ~l mhll~ti~n and the completed
S c~ occurs in a second stage of the ~mhl~tir~n located du~v~ wll from the first
stage of the rl~" ll ."~ ;. " 1. As discussed above the two stage rl ~" ,1."~1;. ." ,`""t. ~ ~IJI ~t~l by
the presffnt invffntion tffnds to reduce NOX ffnissions. Additionally, NOX emissions are
also lowered by the spacing of passages 62 of fuel nozzle 12. Ihe sl~aces bet~veen
passages 62 pffmit IV~ilUlJIaliUll zones to aspirate rrlmhll~hr,n gases into the fuel and
10 thereby reduce NOX emissions.
Uppff and lower secondary oxidant no:z~les 72 and 74 have opposed side walls 76
and 78 (for Uppff secondary oxidant nozle 72) and 80 and 82 (for 10Wff secondaryoxidant nozzle 74) connected to sets of top and bottom walls 84, 85, $6 and 87 are
15 provided which are connected to side walls 76 and 78 and 80 and 82 of upper and lowff
secondary oxidant nozzles 72 and 74, l~liv~l~y. Ihe no~;les are also provided with
back walls 88 and 90. Nozles 72 and 74 are also provided with rectangular discharge
outlets 92 and 94 and vanes 96 and 98 having the same c~ nfigll~tirn as vanes 34 and 36
of Uppff and IOWff nozzles 14 and 16. Although discharge outlets 92 and 94 are designed
20 to inject oxidant in the same ratio as upper and IOWff nozles 14 and 16, an c;ll~
of the present invffntion is possible in which discharge outlets 92 and 94 llave the same
cross-sectional area and thffefore possibly not in the same ratio of upper and lower
nozzles 14 and 16. In the illustrated ~ no~le 72 is provided wi h a front wall
97 within which discharge outlet 92 is defned.
Noz~:les 72 and 74 and burnff 10 are set within pæsages 100, 102, and 104
provided in burner block 75. It should be noted that passage 102 recesses burner 10 from
nozles 72 and 74 to allow for the dvwl~ilwll injection of oxidant by nozzles 72 and 74
and thffefore the second stage of ~." ,l ,~ , Fu~ llllul~, the surfaces 106,108,1 10,
30 andll2Ofburnffblock75,1OcatedinfrontofburnfflOandformingthefrontofpæsage
102, are designed to allow the flame produced by burnff 10 to g~adually divffge.
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2 1 75934 DMR930225 PAIENT
Docket No. 93A224
Conventional quick-disconnect fittings 114 and 116 are connected to upper and
lower secondary oxidant noz~;les 72 and 74, ~ iv~ly~ for illllUdU~,i Ig the secondary
oxidant into the upper and lower secondary oxidant noz~les 72 and 74, I~Li~ y.
S While the invention has been described with reference to preferred ~Illln)dilll~llt,
it would be understood that numerous additions and omissions can be rnade without
departing from the spirit and scope of the invention.
