CA2073223A1 - Burners with reduced pollutant emission - Google Patents
Burners with reduced pollutant emissionInfo
- Publication number
- CA2073223A1 CA2073223A1 CA002073223A CA2073223A CA2073223A1 CA 2073223 A1 CA2073223 A1 CA 2073223A1 CA 002073223 A CA002073223 A CA 002073223A CA 2073223 A CA2073223 A CA 2073223A CA 2073223 A1 CA2073223 A1 CA 2073223A1
- Authority
- CA
- Canada
- Prior art keywords
- supply duct
- fuel
- burner
- oxygen
- supply
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
- 239000003344 environmental pollutant Substances 0.000 title abstract 2
- 231100000719 pollutant Toxicity 0.000 title abstract 2
- 239000000446 fuel Substances 0.000 claims abstract description 21
- 238000002485 combustion reaction Methods 0.000 claims abstract description 15
- 239000007789 gas Substances 0.000 claims description 15
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 13
- 239000001301 oxygen Substances 0.000 claims description 12
- 229910052760 oxygen Inorganic materials 0.000 claims description 12
- 150000001875 compounds Chemical class 0.000 claims 1
- 239000000203 mixture Substances 0.000 claims 1
- 230000003647 oxidation Effects 0.000 abstract description 9
- 238000007254 oxidation reaction Methods 0.000 abstract description 9
- 239000002912 waste gas Substances 0.000 abstract description 5
- 230000015572 biosynthetic process Effects 0.000 abstract description 4
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 abstract 3
- 239000003795 chemical substances by application Substances 0.000 abstract 1
- 150000002500 ions Chemical class 0.000 description 14
- 125000000449 nitro group Chemical group [O-][N+](*)=O 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 229940099990 ogen Drugs 0.000 description 2
- KDYFGRWQOYBRFD-UHFFFAOYSA-N succinic acid Chemical compound OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 2
- 102000007469 Actins Human genes 0.000 description 1
- 108010085238 Actins Proteins 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- AYFVYJQAPQTCCC-GBXIJSLDSA-N L-threonine Chemical compound C[C@@H](O)[C@H](N)C(O)=O AYFVYJQAPQTCCC-GBXIJSLDSA-N 0.000 description 1
- 101100400378 Mus musculus Marveld2 gene Proteins 0.000 description 1
- 241000282320 Panthera leo Species 0.000 description 1
- 241001387976 Pera Species 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010304 firing Methods 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- KJONHKAYOJNZEC-UHFFFAOYSA-N nitrazepam Chemical compound C12=CC([N+](=O)[O-])=CC=C2NC(=O)CN=C1C1=CC=CC=C1 KJONHKAYOJNZEC-UHFFFAOYSA-N 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 208000006379 syphilis Diseases 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/32—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid using a mixture of gaseous fuel and pure oxygen or oxygen-enriched air
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23D—BURNERS
- F23D14/00—Burners for combustion of a gas, e.g. of a gas stored under pressure as a liquid
- F23D14/20—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone
- F23D14/22—Non-premix gas burners, i.e. in which gaseous fuel is mixed with combustion air on arrival at the combustion zone with separate air and gas feed ducts, e.g. with ducts running parallel or crossing each other
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
Abstract
Abstract A burner for low-pollution combustion of a fuel with an oxidation agent is proposed whereby according to the present invention the end of each supply duct for the fuel projects by a section of the length L beyond the end of each supply duct. This allow successive combustion as well as aspiration of furnace waste gases for reduction of the flame temperature, so as to avoid in particular the formation of nitrogen oxide. Emission of pollutants is further reduced by conical widening of the outer side of the end piece of this supply duct.
Description
13LIRNERS WITH REDUCE~D POLl~UlT~lNT E~ISSION
Burners which s~uld display reduced emis~ion aF pollut~nt~, especiaily environment~l~ harm~ul nitro agn o~ide, must b~ ~d~pt~d to a combustion ~echnique uvhich s~ks to decrease the torm~tion ot su~h pollutarfts.
Nrtr~n oxida is formed d~ring the ~mbus~ion prc:~ss essenti~lly from ~e molQcular nitr~n present in ai~ and ~rom th~ nitro~,n combin~d in ~ fuel. Them~al nitro~n oxi~Q ori~in~es in th~ re~ion of ~he flame root or in hot fl~me zon~s a~temp~r~res above 1300'~ ~rom dissoc~d oxyg~n moie~Jles and ni~o~en mol~les. Formation o~ thermal NOX is dspendent on ~n5:;entration of ~e rnolecular nit~ogen as w~ll a~ ~a dis~ociated oxy~n ar7d depends stron~ly on temper~u~e.
primary sign~can~e f~r thg ~uel / ~tOx ~ormation i8 th0 oxyg0rl coneentra~on in ths combu~tion air or the oxidation gas. In both ca~ h~ ~xc~ss air coefficient ~ Is accordingty a maJor in~u~nce tactor.
5tudi 3s show that the concerltration of nitrogan ris~s with the furnac~ chambertemp~rature as w~ll as exponential~ with the ~ombustion air temper~ture; it ha~ a t5 maximurn in the close stoi~hiornetric combu~tion ~one (excess air coemcient approxim~te~ , and ~creases sh~ to ghe su~stoichiom~tric and su~r-stoichiomstric zone (;~ - 0.6 or ~, ~ 1.6). rhe concentra~n ~ ni~rog~n ~an be low~red by redr~ulation of ~aste ~ases, wher~by th~: redu~tion in NOX is exponential~y r~latad to the recy~ed waste gas fl~w (G~s Wàrme ~Gas He;~t] In~ematlonal 38, ~1989~, ~ol.
~0 10, D~mber~
In tho combustion technique the aim is ~ lowsr the oxyç~en ~nd nitfaS~en par~ialpr~ssure and th~ combustion tempera~re in order to r~du~ ~he nitro~en oxide.
Ac~ordin~ly, oxygen-~nrich0d air or pure oxygen is us~ a~ oxi~ation ~as to minimize the supp~ of nitrogen. Howev~r, the r~s~lt of thi~ is hi~her ~arne ~mperatur~s and a higher oxygen p~ial pressure. ~o redu~e the suppiy of oxygen US8 iS made of the recydin~ o~ ~urnt out waste gases into tho eornbustion air or the oxid~tion ~as, effe~iYely reducin~ the oxy~aen c~nten~ by rarefa~ion on ~ ona hand 2 ~73~
and on the other low~ring th~ combustion temperatur~ on the bas~s o~ the waste ~a~
ballast which draws heat frorn th~ flame. This produ~s an ~fficient suppiy of cosled was~e ~ases to the v~cini~y c~f the flaune root.
Cooling combu~ion charges are also u~ed for low~rin~ ~e ftam~ temperature.
~ucces~ive conlbuæti~n is ~Iso suitable ~or ~he same p~Jrp~se (~ W~rme EGas ~est]
Int~n~tional 39, (1~ , v~l. 6, June). Coolin~ cornbu~ion charges, introduced tQ the flame, mu~t ~i~play ~ cer~in ~3~ometry, mu~t be produc~d from special mat~riaJ~ and must b~ pla~d pr~ ly in the burner. Should these co~bustion charg~s not b~
optimally suited to th~ ~rner and the ~bus~ion, the result cc~uld be e;ther irnperfe~t o~olin~ of th~ flame wRi~out e~ential NOx redu~ion, or exc~ss~v~ lowenng o~ the flame t~mperature, related tv higll CO emi~ion.
Dovvn~m, that is, in the direc~on of the fl~m~, bum~rs ~r succ~ssive co~nbustion have drawn supply duc~s for th~ comi~ ion air or ~e oxidation gas whidl in th~ low~r section near the burner ~low, by way ot pr~mary air openings, ~e supply of only a mininlal quantity of oxyg~n an~ which in th~ ~pp~r section ~lo~, by way o~
secondary and ter~iary air opsnin~s, the supp~ of a quantity of o~ç~en corr~spon~in~
to close s~oich.oms~ric combustion. Ths flame temperature consequently remains far below ~hat o~--rring ~uring singl~sta~e combu~tion.
me disadvantaQes of this succe~sive cornb~s$is~n ~ith so-cailed 's~nd~y air obsta~ realized fo~ ~e combustion alr in the 5~,1pply duet are that thesc ob~taGle~, which surround the burner in th8 fo~m of ~ mantte, af~ subjec~ed to a ~tron~ hest eff~ct, sinc~ they are located downstre~m ~f ~he cornbus~ion gas openin~, and that the forn~ of the man~l~ has ~onsidsrable influenc~ on th~ CO emissi~n which mwst be speciflsd prior to use ~ ~he bumer anct which rencler~ unusabte many ernbodiments ~n account of excsssiv9 C:O ~mission.
The o~ect of ~r~ prasent inven~ion is consequently to d~velop an ilnproved ~umer which allo~ ptim~l use of the p~sibilities outline~ for red~cin~3 poll~tants and which avoi~ls the nominat~d ~i~advantages o~ known burner embodiments.
lhis e~ercise is s~lved accordin~ to the present invention by placin3 ~he end ot each supply du~ f~r the f~ei so th~t i~ proj~ts by a section o~ length L bsyond the end of ~ach suppty ctuct for the o~ygen or the gas eontaining oxygen.
~73223 The burn~r according to the pr~ser~ invention compr~s~ ~y way of ~xamp~e o~
a central supply duct ~or th~ h~el an~ s~veral s~Jpp~y du~s conc~ntrically surroundin~
~e form~r for ~he ox~ation g~8 Çontaining oxygen. E~y means of the upply duct for the fuel projectingl 7h~e oxid~tion g~s j0~ Qrnergin~ ~om the indiv~dual r)oz~les can sllck in wast~ gasas trorn the fumace chamb~r, thus also in~r~ combustion p~oducts, by means ~ tl~e resuttin~a suction effect of these jets prlor to mixin~ with the fu~ j~.
The longer the pro~scting section of ~e fue~ supply duc~ more ~ubst~nti~l the reduction of the oxy~en partial pressur~ become~ on aceount o~ ~he inc~der~
r~rff~a~ion.
Th~e jets containin~ ox~n and spteadinç~ downs~ , and whic~ surround the ~ntral ~1 jet ~or examplc, ensure lonç1 rnix~n~ Icngths which guarar~e sven intermixing of ~uei and oxidation gas and avoi~ the formation of 't~ot s,ool~', or ho~
flamo zon~s.
i-urthermo~e, th~ flam~ temp~ratu~ can be lowered by aspiration ~f inert combustion produ~ts and su~stoichiometric combus~on is guarar~ed oVef a large area, effective~ count~actin~ any formation o~ nitro~n oxide.
tt p~o~s ~dva~lta~eous if th~ 10n~th L o~ the proiecting ~ction of th~ supply d :~ct for ~e fuel is many tin e~, pre~rab~ at lea~t ei~ ~htfold, ~e diam~ter c~h of the ~upply duct fol the oxygcn or the ~as containin~ oxyg~n.
2~) At a ~onventiona1 d~artc~ of ~h~ supply ducts for th~ oxi~agion ~ om th~
~upply duct for ~he fuel of around one to thre~ time~ the diametar dh of the oxidation ducts, a sharp~ incid~nt re~u~on o~ emi~ed nitJogen oxide occurs ~t a l~n~th L ~t ths projs~tinç~ s~ction ~hich amount~ to ~ht times the diame~0r dh. This reduction in~reases with an increasing iength L.
2~ Here and h~reina~r, th~ so-calied hydraulic diameter of th8 openings o~ the supply ducts for the oxidation !3as are under~tood as tt e diam~-ter dh. This ~lydraulic diameter is calcul~ted ~rc)m qu~ruplin3 the cros~;-section~ surface A, divid~ by the ~ircumf~r~n~ U of the supply d~s, thu~ dh = 4,~/U. Accordingty, i~ is taken intoaccc: unt ~hE sl~pp~ du~s. whic:h have no ~irclllar opening cross-section, can also ~e put to use.
2~73~23 In an advanta~eous variant, ghe end piec~ o~ sach supp~y duct fo~ ~he fu81 iS inthe form ~ a conicaliy widening con~ on its ou~3;de.
This widened en~ piec~ rep~esents a hindranc~ to the oxid.~ltion g~s j4t oc~urring with consid~rabls impu~, on whi~h a pwtion o~ this je~ is slow~d down. Thi~
5 impulse r~duction and the simul~an~ous Yo~iCity incr~ase ~e quali~y of ths i~termixin~
~f th~ t~el wl~h the o~dation ~s and the stability of the flam0.
The diame~er D at the end of th~ conically wi~necl end piece of each supply du~t ~vr the fuel ~ pr~fera~ly a~ Iaast 1.3 time~ the int~rn~i di~me~er df~ ~ the supply du~t for ~he fuel. In the ~se ~ non-clrcu ar cross-section~, the~e diams~ers ar~ to be understood a~ain as hydr~ullc clian~etsrs.
In or~er to cau~ th~ principl~ of ~uccessive combustlon to r~act ~Yen m~r~
stron~ an ad~fanta~e fur one or morv bors holas to be mad~ through the conically wid~ned end piece of ~a~;h svpply duct for th~ fuel.
A sm~ll portion ~ the oxidat;on gas ~owin~ past ~e widened encl piece ot the fuel supply duct is fed through th~se bore hol~ rld then strikes th~ l jet directly at thQ burner n outh. llle quanti~y of oxy~en passin~ through th~ bore hol~s is de~flrminbd by the diameter ~ the bore hdes and measured ~3:Jch that sub-~toichiofnetnc com~ustion occurs ~irect y at thB flams root. The flan e l~ k~pt stable a~ bumer mouth and burn~ ~hsre with a low flan~e ternperature.
That p~rt of th~ oxida:tion ~as jet dlyened at th~ ~idened snd pie~ finally mixes w~h t7e residual ~u~l in th~ eme~in~a flame and combust~ this ~ith an exc~ss aircoamcient ~. incr~sin~ down~ream. ll~e maiority oS th~ flame then bu~ns ~s~
stoishio~etrical~ ca. 1.05) with flams ~emperatu~s ~w~r than with sinç3le-staç~
combu6tion.
The burner a~cordin~ to the present inv~ntion enables known ~ro~s~ r nitfoQen ~xide raduction such as successive ~m~ustion. vlJaste gas r~circulation, lowe~ing of the combustion ten~pera~ure, even interrnhun~ o~ fu~ and ~xidation ~as by me~ns of the indicated ~eatur~ to ~ realized simultaneo~ly, and ehus i8 suited precominantly ~o fum~ee firing whi~ main~ining incr~sed end v~lues for ni~ogen oxide and ~arbon monoxid~.
~73223 Arl ernb~3dinl0rit shall hereinaft~r descr7be the u5e of the burner according to the pr~ent invention.
Figure 1 schematic~l~ r~pr~snts th~ ion o~ an ~mbodirnent ~f th~
burner accor~ing to ~e pr~sent invention in a side Yiew;
~i~ur~ 2 show~ a vi~w of ~ burn~r mo~h.
The plan vi~v of Fi~urs 2 shows the contrally disposed ~upply duct 1 fu~t in this exampl~, the fiv~ supply du~s 2 fs~ the oxidation gas disposed conc~ntricaliy around the f~rmer, and the other five bore holes :3 throu~h ~e widene~
snd pie~e ~1 supply dllct 1. The numb~:3r an~ g~ometric ~orm of all ~upply du~t~ 1 ~d 2 and bore hol~ 3 can b~ alt~r~d according to ~slrecl u~e.
Flgu~s 1 ~hows an emb~diment of tha bum~ ~ccordin~ to ~he prssent invention with central supply du~t 1 for the natural gas fu~l and supply ducis 2 sutroundin~ thi~
1~ for ths oxidation ~3as, for whic~ o~yçlen i~ usecl. Supply duct 1 proj~cts ov~r the ends of supply duGts 2 a~cording ~o the pr~sent inver,tion by a section o~ the length L. In ~hi~ case approxin-at@ly ninet~n timss ~e v~lue ~f ~e di~m~or C~h of ~upply duc~3 2 is select~cl aS ~8 Isnçlth L.
Bore hoies 3 ~re fnads through ~he ~nically wi~ening ou~er ~ide of t~ ~nd pieçe of supply duct 1 for ~he hlelj thus al3o~Ann~ ~ r~s~rided cluantity ~f oxldation g~s flowing ~rorn supply duc~ 2 to ~ow throu~h. lhs di~m~t~r D at th~ ~nd of the conically widen~d end pie~ amounts to tN~ and a hal~ tirnes the int~rnal diameter cl~ of ~upply duct 1.
On ~ way ~o the end piece o~ supply duct 1 th~ o~y~n j~ts eme~ging from ~ ~ 25 supply du~ts 2 ~uck in cool~d ~om~ustion gases origina~ing at the flame ~ncl, and ~u~
provid~ ~r recirculabon of the ~ombustlon produc~s in the furnace. That portion of thi~
~: oxidation g~s flowin~ through bor~ hol0s 3 is mixed at the burn~r mouth with the natufal gas fuel and thi~ m~u~s csm~usts ther~ xub-stoichiometrically.
The ren~ining portion of th~ ~idaion ~as jet widsning downstrean~ flowing pa~t the end pleca of SL~ y duct 1 for the fuel is mixed with the partially ~mb~sted fuel in the fl~me and fin~lly combusts this oomplet~ly. Fur~h~r reduction ~ the flame 2~73~3 ternperature is achleved by the a~pir~ted Inert c~mbustion produc~s which drav~ heat from the ~ame. At th~ sarne time, the desired su<::c~siv~ combustion for r~ducUon in NOX emission can be r~alized by thi~ arr~ng~m~n~.
- In ~r~mely high ~mpera~ur~ ndanger th~ thefn~al stabil~ty of the burner ma~erial, Cot)iing of s~pply dUct 1 fQr th~ fuel can ~ ~fle~
Utilization of th~ bwn~r accordinç~ ~o the p~esent invention produc~s a lon~, drawn out, soFt y~llow flarne w~h ~ven t~mpe-~ture distributi4n wi~ 'hot 51~ ;'. In ~e end zone the flame burns wnh an ~xoess air coeffici~n~ ~ 1.05. T~e r~cycled/aspirated ~led combustion pro~ucts an~ the succ~ssiYe combustion O pro~ide for a low temperaturs at tha ~am~ raot. SlJccassive c~m~ustion ~n ~ carried out in the burner accordin~ to th~ pres~r~ ~nver~n with much sm~ r lin~ar dlmension~ than ~as hitherto po~sible. A ~rther advantage is the low-noi~e ~omi~u~tion opera~on.
Waste gas m~surem~nts ~uring operation of the burne~ accordin~ to th~
pr~s~nt inv~ntion at a he~t effici~ncy of 1 MW produce around 1~0 mg ~10,~/Nm~ waste gas and around 40 m~ C0 w~h ~ furnace chamb~r temperatur~ o~ oa. 1~ and an oxy~3en conterlt in the was~e ~a~ o~ ca. 5%. ~ early ensures fallinç~ b~w thecorrespon~ TA ~ir end valu~&
Burners which s~uld display reduced emis~ion aF pollut~nt~, especiaily environment~l~ harm~ul nitro agn o~ide, must b~ ~d~pt~d to a combustion ~echnique uvhich s~ks to decrease the torm~tion ot su~h pollutarfts.
Nrtr~n oxida is formed d~ring the ~mbus~ion prc:~ss essenti~lly from ~e molQcular nitr~n present in ai~ and ~rom th~ nitro~,n combin~d in ~ fuel. Them~al nitro~n oxi~Q ori~in~es in th~ re~ion of ~he flame root or in hot fl~me zon~s a~temp~r~res above 1300'~ ~rom dissoc~d oxyg~n moie~Jles and ni~o~en mol~les. Formation o~ thermal NOX is dspendent on ~n5:;entration of ~e rnolecular nit~ogen as w~ll a~ ~a dis~ociated oxy~n ar7d depends stron~ly on temper~u~e.
primary sign~can~e f~r thg ~uel / ~tOx ~ormation i8 th0 oxyg0rl coneentra~on in ths combu~tion air or the oxidation gas. In both ca~ h~ ~xc~ss air coefficient ~ Is accordingty a maJor in~u~nce tactor.
5tudi 3s show that the concerltration of nitrogan ris~s with the furnac~ chambertemp~rature as w~ll as exponential~ with the ~ombustion air temper~ture; it ha~ a t5 maximurn in the close stoi~hiornetric combu~tion ~one (excess air coemcient approxim~te~ , and ~creases sh~ to ghe su~stoichiom~tric and su~r-stoichiomstric zone (;~ - 0.6 or ~, ~ 1.6). rhe concentra~n ~ ni~rog~n ~an be low~red by redr~ulation of ~aste ~ases, wher~by th~: redu~tion in NOX is exponential~y r~latad to the recy~ed waste gas fl~w (G~s Wàrme ~Gas He;~t] In~ematlonal 38, ~1989~, ~ol.
~0 10, D~mber~
In tho combustion technique the aim is ~ lowsr the oxyç~en ~nd nitfaS~en par~ialpr~ssure and th~ combustion tempera~re in order to r~du~ ~he nitro~en oxide.
Ac~ordin~ly, oxygen-~nrich0d air or pure oxygen is us~ a~ oxi~ation ~as to minimize the supp~ of nitrogen. Howev~r, the r~s~lt of thi~ is hi~her ~arne ~mperatur~s and a higher oxygen p~ial pressure. ~o redu~e the suppiy of oxygen US8 iS made of the recydin~ o~ ~urnt out waste gases into tho eornbustion air or the oxid~tion ~as, effe~iYely reducin~ the oxy~aen c~nten~ by rarefa~ion on ~ ona hand 2 ~73~
and on the other low~ring th~ combustion temperatur~ on the bas~s o~ the waste ~a~
ballast which draws heat frorn th~ flame. This produ~s an ~fficient suppiy of cosled was~e ~ases to the v~cini~y c~f the flaune root.
Cooling combu~ion charges are also u~ed for low~rin~ ~e ftam~ temperature.
~ucces~ive conlbuæti~n is ~Iso suitable ~or ~he same p~Jrp~se (~ W~rme EGas ~est]
Int~n~tional 39, (1~ , v~l. 6, June). Coolin~ cornbu~ion charges, introduced tQ the flame, mu~t ~i~play ~ cer~in ~3~ometry, mu~t be produc~d from special mat~riaJ~ and must b~ pla~d pr~ ly in the burner. Should these co~bustion charg~s not b~
optimally suited to th~ ~rner and the ~bus~ion, the result cc~uld be e;ther irnperfe~t o~olin~ of th~ flame wRi~out e~ential NOx redu~ion, or exc~ss~v~ lowenng o~ the flame t~mperature, related tv higll CO emi~ion.
Dovvn~m, that is, in the direc~on of the fl~m~, bum~rs ~r succ~ssive co~nbustion have drawn supply duc~s for th~ comi~ ion air or ~e oxidation gas whidl in th~ low~r section near the burner ~low, by way ot pr~mary air openings, ~e supply of only a mininlal quantity of oxyg~n an~ which in th~ ~pp~r section ~lo~, by way o~
secondary and ter~iary air opsnin~s, the supp~ of a quantity of o~ç~en corr~spon~in~
to close s~oich.oms~ric combustion. Ths flame temperature consequently remains far below ~hat o~--rring ~uring singl~sta~e combu~tion.
me disadvantaQes of this succe~sive cornb~s$is~n ~ith so-cailed 's~nd~y air obsta~ realized fo~ ~e combustion alr in the 5~,1pply duet are that thesc ob~taGle~, which surround the burner in th8 fo~m of ~ mantte, af~ subjec~ed to a ~tron~ hest eff~ct, sinc~ they are located downstre~m ~f ~he cornbus~ion gas openin~, and that the forn~ of the man~l~ has ~onsidsrable influenc~ on th~ CO emissi~n which mwst be speciflsd prior to use ~ ~he bumer anct which rencler~ unusabte many ernbodiments ~n account of excsssiv9 C:O ~mission.
The o~ect of ~r~ prasent inven~ion is consequently to d~velop an ilnproved ~umer which allo~ ptim~l use of the p~sibilities outline~ for red~cin~3 poll~tants and which avoi~ls the nominat~d ~i~advantages o~ known burner embodiments.
lhis e~ercise is s~lved accordin~ to the present invention by placin3 ~he end ot each supply du~ f~r the f~ei so th~t i~ proj~ts by a section o~ length L bsyond the end of ~ach suppty ctuct for the o~ygen or the gas eontaining oxygen.
~73223 The burn~r according to the pr~ser~ invention compr~s~ ~y way of ~xamp~e o~
a central supply duct ~or th~ h~el an~ s~veral s~Jpp~y du~s conc~ntrically surroundin~
~e form~r for ~he ox~ation g~8 Çontaining oxygen. E~y means of the upply duct for the fuel projectingl 7h~e oxid~tion g~s j0~ Qrnergin~ ~om the indiv~dual r)oz~les can sllck in wast~ gasas trorn the fumace chamb~r, thus also in~r~ combustion p~oducts, by means ~ tl~e resuttin~a suction effect of these jets prlor to mixin~ with the fu~ j~.
The longer the pro~scting section of ~e fue~ supply duc~ more ~ubst~nti~l the reduction of the oxy~en partial pressur~ become~ on aceount o~ ~he inc~der~
r~rff~a~ion.
Th~e jets containin~ ox~n and spteadinç~ downs~ , and whic~ surround the ~ntral ~1 jet ~or examplc, ensure lonç1 rnix~n~ Icngths which guarar~e sven intermixing of ~uei and oxidation gas and avoi~ the formation of 't~ot s,ool~', or ho~
flamo zon~s.
i-urthermo~e, th~ flam~ temp~ratu~ can be lowered by aspiration ~f inert combustion produ~ts and su~stoichiometric combus~on is guarar~ed oVef a large area, effective~ count~actin~ any formation o~ nitro~n oxide.
tt p~o~s ~dva~lta~eous if th~ 10n~th L o~ the proiecting ~ction of th~ supply d :~ct for ~e fuel is many tin e~, pre~rab~ at lea~t ei~ ~htfold, ~e diam~ter c~h of the ~upply duct fol the oxygcn or the ~as containin~ oxyg~n.
2~) At a ~onventiona1 d~artc~ of ~h~ supply ducts for th~ oxi~agion ~ om th~
~upply duct for ~he fuel of around one to thre~ time~ the diametar dh of the oxidation ducts, a sharp~ incid~nt re~u~on o~ emi~ed nitJogen oxide occurs ~t a l~n~th L ~t ths projs~tinç~ s~ction ~hich amount~ to ~ht times the diame~0r dh. This reduction in~reases with an increasing iength L.
2~ Here and h~reina~r, th~ so-calied hydraulic diameter of th8 openings o~ the supply ducts for the oxidation !3as are under~tood as tt e diam~-ter dh. This ~lydraulic diameter is calcul~ted ~rc)m qu~ruplin3 the cros~;-section~ surface A, divid~ by the ~ircumf~r~n~ U of the supply d~s, thu~ dh = 4,~/U. Accordingty, i~ is taken intoaccc: unt ~hE sl~pp~ du~s. whic:h have no ~irclllar opening cross-section, can also ~e put to use.
2~73~23 In an advanta~eous variant, ghe end piec~ o~ sach supp~y duct fo~ ~he fu81 iS inthe form ~ a conicaliy widening con~ on its ou~3;de.
This widened en~ piec~ rep~esents a hindranc~ to the oxid.~ltion g~s j4t oc~urring with consid~rabls impu~, on whi~h a pwtion o~ this je~ is slow~d down. Thi~
5 impulse r~duction and the simul~an~ous Yo~iCity incr~ase ~e quali~y of ths i~termixin~
~f th~ t~el wl~h the o~dation ~s and the stability of the flam0.
The diame~er D at the end of th~ conically wi~necl end piece of each supply du~t ~vr the fuel ~ pr~fera~ly a~ Iaast 1.3 time~ the int~rn~i di~me~er df~ ~ the supply du~t for ~he fuel. In the ~se ~ non-clrcu ar cross-section~, the~e diams~ers ar~ to be understood a~ain as hydr~ullc clian~etsrs.
In or~er to cau~ th~ principl~ of ~uccessive combustlon to r~act ~Yen m~r~
stron~ an ad~fanta~e fur one or morv bors holas to be mad~ through the conically wid~ned end piece of ~a~;h svpply duct for th~ fuel.
A sm~ll portion ~ the oxidat;on gas ~owin~ past ~e widened encl piece ot the fuel supply duct is fed through th~se bore hol~ rld then strikes th~ l jet directly at thQ burner n outh. llle quanti~y of oxy~en passin~ through th~ bore hol~s is de~flrminbd by the diameter ~ the bore hdes and measured ~3:Jch that sub-~toichiofnetnc com~ustion occurs ~irect y at thB flams root. The flan e l~ k~pt stable a~ bumer mouth and burn~ ~hsre with a low flan~e ternperature.
That p~rt of th~ oxida:tion ~as jet dlyened at th~ ~idened snd pie~ finally mixes w~h t7e residual ~u~l in th~ eme~in~a flame and combust~ this ~ith an exc~ss aircoamcient ~. incr~sin~ down~ream. ll~e maiority oS th~ flame then bu~ns ~s~
stoishio~etrical~ ca. 1.05) with flams ~emperatu~s ~w~r than with sinç3le-staç~
combu6tion.
The burner a~cordin~ to the present inv~ntion enables known ~ro~s~ r nitfoQen ~xide raduction such as successive ~m~ustion. vlJaste gas r~circulation, lowe~ing of the combustion ten~pera~ure, even interrnhun~ o~ fu~ and ~xidation ~as by me~ns of the indicated ~eatur~ to ~ realized simultaneo~ly, and ehus i8 suited precominantly ~o fum~ee firing whi~ main~ining incr~sed end v~lues for ni~ogen oxide and ~arbon monoxid~.
~73223 Arl ernb~3dinl0rit shall hereinaft~r descr7be the u5e of the burner according to the pr~ent invention.
Figure 1 schematic~l~ r~pr~snts th~ ion o~ an ~mbodirnent ~f th~
burner accor~ing to ~e pr~sent invention in a side Yiew;
~i~ur~ 2 show~ a vi~w of ~ burn~r mo~h.
The plan vi~v of Fi~urs 2 shows the contrally disposed ~upply duct 1 fu~t in this exampl~, the fiv~ supply du~s 2 fs~ the oxidation gas disposed conc~ntricaliy around the f~rmer, and the other five bore holes :3 throu~h ~e widene~
snd pie~e ~1 supply dllct 1. The numb~:3r an~ g~ometric ~orm of all ~upply du~t~ 1 ~d 2 and bore hol~ 3 can b~ alt~r~d according to ~slrecl u~e.
Flgu~s 1 ~hows an emb~diment of tha bum~ ~ccordin~ to ~he prssent invention with central supply du~t 1 for the natural gas fu~l and supply ducis 2 sutroundin~ thi~
1~ for ths oxidation ~3as, for whic~ o~yçlen i~ usecl. Supply duct 1 proj~cts ov~r the ends of supply duGts 2 a~cording ~o the pr~sent inver,tion by a section o~ the length L. In ~hi~ case approxin-at@ly ninet~n timss ~e v~lue ~f ~e di~m~or C~h of ~upply duc~3 2 is select~cl aS ~8 Isnçlth L.
Bore hoies 3 ~re fnads through ~he ~nically wi~ening ou~er ~ide of t~ ~nd pieçe of supply duct 1 for ~he hlelj thus al3o~Ann~ ~ r~s~rided cluantity ~f oxldation g~s flowing ~rorn supply duc~ 2 to ~ow throu~h. lhs di~m~t~r D at th~ ~nd of the conically widen~d end pie~ amounts to tN~ and a hal~ tirnes the int~rnal diameter cl~ of ~upply duct 1.
On ~ way ~o the end piece o~ supply duct 1 th~ o~y~n j~ts eme~ging from ~ ~ 25 supply du~ts 2 ~uck in cool~d ~om~ustion gases origina~ing at the flame ~ncl, and ~u~
provid~ ~r recirculabon of the ~ombustlon produc~s in the furnace. That portion of thi~
~: oxidation g~s flowin~ through bor~ hol0s 3 is mixed at the burn~r mouth with the natufal gas fuel and thi~ m~u~s csm~usts ther~ xub-stoichiometrically.
The ren~ining portion of th~ ~idaion ~as jet widsning downstrean~ flowing pa~t the end pleca of SL~ y duct 1 for the fuel is mixed with the partially ~mb~sted fuel in the fl~me and fin~lly combusts this oomplet~ly. Fur~h~r reduction ~ the flame 2~73~3 ternperature is achleved by the a~pir~ted Inert c~mbustion produc~s which drav~ heat from the ~ame. At th~ sarne time, the desired su<::c~siv~ combustion for r~ducUon in NOX emission can be r~alized by thi~ arr~ng~m~n~.
- In ~r~mely high ~mpera~ur~ ndanger th~ thefn~al stabil~ty of the burner ma~erial, Cot)iing of s~pply dUct 1 fQr th~ fuel can ~ ~fle~
Utilization of th~ bwn~r accordinç~ ~o the p~esent invention produc~s a lon~, drawn out, soFt y~llow flarne w~h ~ven t~mpe-~ture distributi4n wi~ 'hot 51~ ;'. In ~e end zone the flame burns wnh an ~xoess air coeffici~n~ ~ 1.05. T~e r~cycled/aspirated ~led combustion pro~ucts an~ the succ~ssiYe combustion O pro~ide for a low temperaturs at tha ~am~ raot. SlJccassive c~m~ustion ~n ~ carried out in the burner accordin~ to th~ pres~r~ ~nver~n with much sm~ r lin~ar dlmension~ than ~as hitherto po~sible. A ~rther advantage is the low-noi~e ~omi~u~tion opera~on.
Waste gas m~surem~nts ~uring operation of the burne~ accordin~ to th~
pr~s~nt inv~ntion at a he~t effici~ncy of 1 MW produce around 1~0 mg ~10,~/Nm~ waste gas and around 40 m~ C0 w~h ~ furnace chamb~r temperatur~ o~ oa. 1~ and an oxy~3en conterlt in the was~e ~a~ o~ ca. 5%. ~ early ensures fallinç~ b~w thecorrespon~ TA ~ir end valu~&
Claims (7)
1. Burner for combustion of a fuel with oxygen or a gas containing oxygen with at least one supply duct for the oxygen or the gas containing oxygen and at least one supply duct for the fuel, characterized in that the end of each supply duct for the fuel is placed so that it projects by a section of length L beyond the end of each supply duct for the oxygen or the gas containing oxygen.
2. Burner as claimed in Claim 1, characterized in that the length L
of the projecting section of the supply duct for the fuel is many times preferably at least eightfold, the diameter dh of the supply duct for the oxygen or the gas containing oxygen.
of the projecting section of the supply duct for the fuel is many times preferably at least eightfold, the diameter dh of the supply duct for the oxygen or the gas containing oxygen.
3. Burner as claimed in Claims 1 or 2, characterized in that the end piece of each supply duct for the fuel is in the form of a conically widening cone on its outside.
4. Burner as claimed in Claim 3, characterized in that the diameter D at the end of the conically widened end piece of each supply duct for the fuel is at least 1.3 times the internal diameter dg of this supply duct.
5. Burner as claimed in Claims 3 or 4, characterized in that one or more bore holes are made through the conically widened end piece of each supply duct for the fuel.
6. A burner substantially hereinbefore described with reference to the drawings and/or examples.
7. The steps, features, compositions and compounds disclosed herein or referred to or indicated in the specification and/or claims of this application, individually or collectively, and any and all combinations of any two or more of said steps or features.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DEP4122253.9 | 1991-07-05 | ||
| DE4122253A DE4122253A1 (en) | 1991-07-05 | 1991-07-05 | BURNER WITH REDUCED POLLUTANT EMISSION |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2073223A1 true CA2073223A1 (en) | 1993-01-06 |
Family
ID=6435485
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002073223A Abandoned CA2073223A1 (en) | 1991-07-05 | 1992-07-06 | Burners with reduced pollutant emission |
Country Status (5)
| Country | Link |
|---|---|
| EP (1) | EP0521522A3 (en) |
| AU (1) | AU648183B2 (en) |
| CA (1) | CA2073223A1 (en) |
| CZ (1) | CZ208192A3 (en) |
| DE (1) | DE4122253A1 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2709812B1 (en) * | 1993-09-09 | 1995-10-13 | Air Liquide | Combustion process. |
| FR2774895B1 (en) | 1998-02-16 | 2000-06-30 | Braun Celsa Sa | MEDICAL DEVICE COMPRISING A ROD PROVIDED WITH A MEANS FOR ABSORBING AXIAL CONSTRAINTS |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2375625A (en) * | 1940-12-27 | 1945-05-08 | Frederick S Bloom | Combustion apparatus |
| US3088681A (en) * | 1955-02-01 | 1963-05-07 | Bloom Eng Co Inc | Atomizing oil burner nozzle |
| FR2462657A1 (en) * | 1979-07-25 | 1981-02-13 | Air Liquide | Liquefied gas atomiser and burner - has outside sleeve for combustion air and central pipe for atomised fuel |
| EP0124146A1 (en) * | 1983-03-30 | 1984-11-07 | Shell Internationale Researchmaatschappij B.V. | Method and apparatus for fuel combustion with low NOx, soot and particulates emission |
| US4988285A (en) * | 1989-08-15 | 1991-01-29 | Union Carbide Corporation | Reduced Nox combustion method |
| US4986748A (en) * | 1989-12-15 | 1991-01-22 | Corning Incorporated | Wide range oxy-fuel burner and furnace operation |
-
1991
- 1991-07-05 DE DE4122253A patent/DE4122253A1/en not_active Withdrawn
-
1992
- 1992-06-30 AU AU19326/92A patent/AU648183B2/en not_active Ceased
- 1992-07-02 CZ CS922081A patent/CZ208192A3/en unknown
- 1992-07-03 EP EP19920111336 patent/EP0521522A3/en not_active Ceased
- 1992-07-06 CA CA002073223A patent/CA2073223A1/en not_active Abandoned
Also Published As
| Publication number | Publication date |
|---|---|
| AU648183B2 (en) | 1994-04-14 |
| CZ208192A3 (en) | 1993-08-11 |
| EP0521522A2 (en) | 1993-01-07 |
| AU1932692A (en) | 1993-01-07 |
| EP0521522A3 (en) | 1993-03-03 |
| DE4122253A1 (en) | 1993-01-07 |
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