US1740249A - Method op burning liquid fuel - Google Patents

Description

Dec. "T7, 1 929. A. L. KLEES I METHOD OF BURN'I'NG 4LIQUID FUEL Filed Feb. 15'. 1926 Patented Dec; 17, 1929 UNIT-Ep STATES PATENT j foFFICE 'y ALBERI* Ig. vRLRRS, OR NRW YORK, N. Y., AssIGNOR To 'COMRUSTION UTILITIES COR- rORATION, ORNRW YORK, N. Y., CORPORATION or 'MAINE METHOD OF yBURNING 'LIQUID RUBI;

:Application filed february 15, 1926. Serial No. 88,196.'

The present invention relates to the oombustion of liquid fuels and more-"particularly to nnprovemeuts in the operation-of burners for gas and oil fired domestic heating furing furnaces without DECES.

is ordinarily accomplishediin domestic heatlng furnaces by atomlzing 'a'Jct of the loil .with air'or steam'under pressure'in the'combustion chamber of a furnace-through a small orifice nozzle. and -ivnit-inY the-airor steam' oil mixture by contacting-"ity with the flame from a gas pilotlight or 'other source of heat as it leaves the tip of the nozzle.' lIt has been posed system the air-oil mixture issuing from the atomizing nozzle is ignited and rapidly vaporized by heat supplied from the flame of -a gas burner Of relatively much greater heating power than that furnished by the ordinary-.pilot light. -Accordingly with a combination gas and oil burnersuch as that suggested it is possible to burn a relatively much cheaper grade of Oil than can be used in the Ordinary type of burner,` burning oil only.

tion of oil' in a furnace veither equipped with the common type of oil burner or with a gasoil burner such as that suggested is generally accompanied by a flickering flame and a roaring noise of varying' intensity which is very objectionable and disturbing to the householder.

The primary object of the present invention is to provide an improved method for effecting the combustion of oil in house heatany objectionable combustion noise. l A furtherobject of the invention is to pro- -vide a method of burning Oil in house heat-v ing furnaces with a smoother and-more efficient lame than .that commonly produced with the ordinary type of oil or oil-gas burner above referred to.A 1 v v With-these and other Objects in view the invention consists in the'improved method of burning liquid fuels hereinafter described and particularly defined in the claims.

The various features of the invention are ,I A Y illustrated inthe accompanying drawings, in The combustion of oil or other 'liquid fuel' which Figil is a view in elevation, partly in sec- "burnerapparatustsuitablefor burning Oil in accordance with -fthe Y method embodying the 'l preferred-l` forniy of the p'resent invention. i F1gk2'1s vert-lealsection of theoil atomizingi'i'ozzle illustratedv in Fig. 1;'andI I Fig-'3 is apla'n viewwith parts cut away showing'the relative rarrangement of the gas burnerand oilratomiz'ing nozzle, taken on line 3;-3 offFig.1:i"`

- Thebasic'principle underlying the present invention has beenevol'ved as the result of a large numberfo'f"experiments carried out to determineV thesou'rce of the 'considerable amount of noise produced when an air-Oil mixture is'l injected under pressure into the combustion'chamber of a house heating furnace and is ignited as it leaves the tip of the atolnizing nozzle. It has' been determined by theseexp'eriment's that the roaring noise set up by the. combustion ofl oil according to thel methods now commonly employed in the It has been found, however, that the combu's- I burners of house heating furnacesvresults in great part from the practice of attempting to ignitethe atomi'zed air-oil mixture entering the combustion chamber at a time when the velocity of the jet issuing from the nozzle is greater (or sometimes less) than the rate of flame oil mixture.

Accordingly"one feature of the present invention contemplates a new design of gas-oil burner having the gas burner so arranged relative to the oil atomizing nozzlethat the ignition of the atomized Oil-air mixture'entering the combustion chambenwill' be effected by the gas flame at the instant that the' velocity of the jet issuing'from the tip yof the atomizing nozzle substantially equals the rate of flame vpropagation of the mixture.'

In the drawings 1 0 indicates a standard type of coal'burning domestic heating furpropagation of the atomized air- `nace equippedwith a combination gas and oilV burner-.apparatus 12 ofthe type and arrange-- ment embodying the preferred form of` the presentV invention. In installing apparatus 12 in the furnace the coal burnin'ggrates with Whichthe furnace'may `beorig'jnally.equipped are -,.removed=andf.a;zeast #oresheetmetal. cone `frustum 14 .is placed in the furnace Withits '..baseresting-onthe lugs or rings 16 ordinarily used ALto support the grate. The cone` 14 is centrally ap'ertured -to-permitthe flameissuing from an oil atomizinmnozzle .18 to pro-4 ject into the lower part o the 4furnace with! out coming into contact- Witlnthe-surface of fg-2'@ Theburnerfapparatus.12 comprises anannular gas 'burner 24, preferably cast as an integral. part-ofl thecone l14,.and the oilat'omizing nozzle .18, mounted cent-rally. of the gas }burner.. .2and in .a horizontal .plane vertically i/ ispaced. af'substantial distance belovv.the-'planey i of the;gas lburner. .Thegas burner 24`includes.

a largenumbenoi individualburner. tips 26 extending in a ,ring around .itsinner edge-'with 'their bores"directed horizontallyand radially toward'lf'the central aperture: of lthe burner, so that!iames issuingrom tipsL26 liein-a posi- Y.tionff'to'f'strike.the-edgeof-fand be drawn at -riglt angles into a jet. of atomized-loil issuing i. ron 1 the-centrally;l positioned Voil nozzle 18. ','lhe 4cone 14. entirely surrounds and .extends upwardly. .a .short distance above the flevelfofthe burner tips .26. Restingon brack- -5et`s`128 on the 'upper edge of cone 14 is a spider 30 supporting a central :plate .orbutton'2, .preferablymade of cast iron .and centrally vpositioned :inf the furnace so as to contact with l and:spread oill flame to promote the thorough minglingof the oil'ame `from nozzle 18 With the gasiame from burner `24.

In accordance'with `the present invention Y an idealv apparatus arrangement for .burning hea 'fuel oil is `,provided by burning gas withina refractoryl conetomaintaina 'radiatingsu'rface Whichlvvill readily ignite and .va-

.l50 porizeeventhe heaviest grades of fuel oil. "f The" burner is preferably so operated that at '.thetime oil isintroduced into thevfurnace through the nozzle 18, the gas from burner 24 willbe burningat its maximum. Thereforethe oil is introduced into. a heatedchamber and into a burning gas flame, thus insuringV its complete;combustion. The .means for `supplyinggas"and air to burner 24 form no f, partei the-present invention and accordingly 50 are illustrated. only, diagrammatically'4 in. the

1alrwiirssA Agpipe 3I '..iisishowm preferably connected to a'fgas ,supply which .maybe the ordinary citygas. Apipe-36 isftakenol from' pipe 34 65 .andleadsthroughthe .flue20.to apilot burner 38 adjacentthe 'gasxburner 24. 'Pipe' 34- extends to a' nozzle 40 arranged tov deliver'i-nto an air and gas mixing conduit .42,.fsupported in flue 20. The` conduit v42 is-.equip'ped with air openin s 44at its `outer end'aroun'd-the. .exterior o ...g-gas v no zzle x--. 4O. .Thee-gas 'flowz'ing through. nozzle-11.40 ldraws Y@proportioned amounts of primary airin aroundfthe edges of conduit l42;,through .passages -44;and the airl and as after' mixing' in-"conduit-.42 pass into'^'the urner'f24.' 'Inorder that-ithe'riame of theuga's .burnermay be regulated as desired,

a cap or'shutter 146 is movably .mounted on a vthreaded section of the nozzle 40. When moved up against the end of conduit 42 this shutter `closes;.the air passages44 .and -shuts voff the .flowofairfinto the mixing-chamber.

Therefore by'screwing the-cap e46-back and forth-on.nozzle-theflow offair to theburner ture of gas andrairfisfadmitted.-to. conduit .42 vand burner .224; Sufficient secondary@ fair. `-for v .burning .the .gasfin 4case =no oil 4is..enteringthe furnace, Willleak in through -smallropenings .around .the-base .of .the-'.furnacetand iiue -:20,

. 4and when oilf lisbeingsu pliedto theffurnace additional airferyillvibe =a initted Vin al manner hereinafter described. If. the burner @apparatus is a.part-0Lafhouseheating y's lstems/the hand -valve l48 onthegas.line;':1nay..l epreferably Areplaced fbysa snap Avalve-roifsome-sort, together .with-automatic means .forloperating the valve inaccordancefwithf,thencall'for heat registered. by la thermostat in --some Lpart.v 'of the h ouse (notshown).

The means. for supplying foilV .to thelnozzle 18 -and the Vmeans for starting and-.stopping the How. of oil. form no partof .the present invention. and accordingly are: merely..- indicated diagrammatically :inthe drawing.. .Oil froma storagetank or othersourceofsupply is preferably `ra-ised'- by.v pump Isuctionfto i* van oil pump 5,0 through a pipe 52 andfis- -forced by the' pump to nozzle 18-throughfa= pipe 54.

Anyfexcess oil handled `by the-pump-randffnot needed .atthe burner-is byfpassed -to.a' pipe -55 yand returned `to--storage TheoilrpumpfO illustrated in the drawing is of? the -valveless `oroscillating rotor type.' As indicated inthe drawings Vthe pump is mountedzin..align ment with the drive lshat'of-an.electricrmotor 56 'which is energized .through .a 'circuit V'58. Intermediate oil pump 50 :and motor 56 is a pump x'60. furnishing air under y:pressure for atomizing oil delivered by pump @50 at the .nozzle 18. .fThe casing of-air :pump 66 is .fixed to thecasingsof motor 56and oilpump 50 thas its' shaft. -in alignment 1with :those` 0f the motor andzairfpump. 'llhefmotorand pumps -50 and 60 .form .aulnitary structure. Air pump receives-air throughanzinlet 612a-nddelivers. it .throughrfazpipe v.62, supported lin *Hue 20;; to the atomizingf'nozzle' 18.* Though' 'not' illustrated thermostaticcontrolswitches 'f are Apreferably employed-inYtliefcircuit of motor'g'it'for-thci purposeof'automaticallystarton` the lfurnac'e 10. lLikewise the pilot38 is equipped with a coil 64`of a fluid-filled thermostat which will-operate; upon the extinction of the flame ofthe pilot, preferablyon a fluid motor controlled 'switch opening the circuit to-lnotor 50 and also on a'snap'valve `or other device cutting ofi" the supply of gas to burner 24. A similar device Gtfpositioned on lthe top of the furnace may be'employed to interrupt the circuit of motort and thus shut down the motor and oil pump'O whenever the temperature of the furnace or the pressure on the boiler exceeds-certaindesired limits. These various automatic safety devices form no part of the present invention and accordingly have'not been fully villustratedand' will not be moreconlpletely'describedin connection' with `the* presentcase.

' As already indicated primary air for atom'- izing and burning the oil-is'supplied by pump 60 through pipe T62 ltol theatomizing nozzle'` 18. A relief valv'e v68near tlieliead-'of pipe 62 affords the means bothforfproportioning the amount of air to oil supplied .to nozzle 18 and also for regulating the pressure builtup in line G2 and the resultant' velocity with which the atomized oil-airmixturissues into the furnace from the tip of nozzlelS. For the purpose of supplying-additional second-` ary air to burner apparatus' 12 when oil as Well as gas-is being burned an air inlet-aperture is providedin` flue'20,` aperture 70 being closed by a damper 72encept when oil is being burned. Damper 72 is hinged at 74 to the inside of the bottomlfsurfaceof Hue; 20, so that the'damper remains normally closed by its own Weight. ln vorder to open-damper 72 when needed link 76 is connected to the unhinged part of the damper. At its' opposite end link 76 is connected to a flexible operating diaphragm 78. Diaphragm 78 is rigidly heldin place bythe two 'sections of casing 80 so as to form a tight closure for a chamber 82 in the lower portion'of the Acasing. A pipe 84 connects the interior of 'primary air supply' line 62 with the interiorlof chamber 82 beneath diaphragm 78. With thisarrangement thesame air pressure is maintained in chamber 82that exists in pipe 62. Therefore when the air pump 60'is put into operation the diaphragm 78'Will'be automatically raised and the damper `72Will be opened to admit secondary air intol flue 20.:

' As a result of a large numberoftests made vwith the present burner apparatusyusing many classes of oil fieldsinject'e'd into a'fur- `nace at the relatively low atomizingairi pressure, it has been determined that a condition of substantially noiseless combustion-"With a correspondingly v'high' degree of combustion efiiciency cani-'be Vmaintained in the furnace when the gas burner 24 is elevated a distance approximatingl4 above lthe tip of oil nozzle 18.`A In other words it has been found that by adjusti-nfrthe .volume `of air passed by blower 60 tooilhurner 1'8 'bymea-n's Aof valve 68' in accordance :with the type of oil fuel being burned-'thev same? relative settingV of #the gas burner and oil nozzle may be used when burninga wide variety of oils in the furnace without producing any undesirable amount of combustion noise. Thus lthe valve 68 can be adjusted to change the proportions of air and oil and to vary'the velocity of the oil-air mixturek issuing from the tip'of nozzle 18 to maintain the point'of ignition of the .oil-air mixture substantially stationary at approximately the 'desired point at Which'the velocity of the jet issuing from the'nozzle has attained a valueequaljto the rate of flame propagation of the various' air and oil mixtures-supplied.

In order to provide for different fuel conditions','means are provided for securing a Y'positive adjustment of the distance separating the tipof-.nozzle -18 l'from the plane of burner tips 26. Thefdevice `illustrated in the drawing consists essentially of al small'jack screw arrangement SG'Which is shown positioned under the base of nozzle 18. By rotating 'a Worm 88 a rotary movement maybe imparted to a pinion 90. y,"Ilie .bore of pinion 90 is threaded so that by'its rotation it' raises or lowersa threaded plunger92. .The headof plunger 92 is positioned-tocarry the Weight of nozzle 18 and by the movement of the plunger it is possible to raise or lower the nozzle through a short' distance'vvhichQthough limited 'by the angle through' which it is safe t o swing the pipes 625 54 and 84, is still sufficient in conjunction withthe alternate adjustment-'afforded by valve 68 to give a wide range of ad j ustment to the burner apparatus and thu'sinsure lnois'eless combustion while burning va Wide variety of fuel oils.` I n order to hold the nozzle18 in a central position in the furnace brackets' 94,` attached to the base ofv cone 14, extend'dovvnwardlyand form with 'their ends a sleeve journal9'5 permitting` vertical but `not horizontalmovement of the nozzle. p

The details' of construction of atomizing nozzle 18 are-illustrated in Fig. 2. Oilor other liquid fuel enters thev lower portion of the nozzle casing lfrom pipe 54 through a chamber 96, the top ofwhic'h is formed into a. cap 98. The air`for atomizin'g the oil enters a chamber 100, intowhich is threaded the pipe 62-leading from air pump 60. From chamber 100 theairpasse's'upwardly through a nipple 102'into an annular opening104 surrounding a nozzle 106. A pipe 108 Ais threadedin ca p 98 and runs cent-rally through chamber 10G-and nipple 102,fto conduct oil into the bore of burner nozzle106bi-A protecting cap 110 may if desired be screwed onto threads on' the casingof nozzle 18. The upper end of nipple spac eolfromv the nozzle so that air may pass .uparound the outside of the nozzle through anl annularaperture 114. Oil is delivered through the pipe 108 and the interior bore of nozzle 106 to the aperture 112 so that air and oil are immediately and thoroughly comminvgledas they issue from the lapertures 112 and 114'res'pective1y,. 'f

The operation of the apparatus according to the present invention may be briefly summarized as follows: During periods'of nor.- mal temperature only the pilot burner 38 is left burningn As the temperature begins to fallthe gas valve48 is opened and cap 46 at the head of conduit 42'is adjusted to admit suitable proportions of: gas and air to burner 24'. When the maximumsupply of gas has been reached the electric circuit of motor 56 is closed yand the oil ump 50 and air pump 60 will be simultaneously set in operation to supplyoil and air under pressure to nozzle 1S.

eforetheoilpump starts up the cone 14 will have; become highly heated by reason of the c ofmlo ustiofn of gasissuing from the tips of b u rner,` 24, sothat when the oilis introduced intothefurnace from nozzle 18 Iit will be atomized into'the gas flame from burner 24 and into the. highly heated chamber formed byjc one114.- When the oil pump is started by 'I notgr 1756 the damper 72 ,in flue 20 is graduallypened 'as lthe air pressure inv pipe 62 builds up; This furnishes the secondary air forthe oil and gas flame supplied by burner apparatus 16. f The oil and gascontinue to burn in the furnace until the heat supplied by the b oileris sufficient to raise the tempe'rature in the house to normal, at which timethe circuit to the motor 56 will be broken, preferably .fiutomaticall and the motor, oil pump and blwverfvvill stop. If the temperature continues to' rise the supply of gas to burner 24 can 'be cutoff by closing valve 48. A

4As previously indicatedthe hand valve 48 A illustrated in the drawings may be replaced by a vsnap valve of some sort with automatic means for controlling the operation of such valvez'and the supply of gas to burner 24 in accordancewith the call for heat registered by'a thermostat.

As previously pointed out prior designs of oil and gas-and-oil burningdomestic furnaces are so arranged that the pilot flame or other source of ignition is applied to the atomized oil-air mixture at the instant it enters the combustion chamber from the atomizingnozzle'. Consequently in operating these .burners an unstable condition of combustion is commonly present at the source of ignition and the oil flame which is produced continually bucks and flickers and generates a considera-ble amount of roaring noise. According tothe lpresent design an elevatedsource vproper distance from the tip of the oil burner so that the velocity of the atomized oil-air mixture is substantially equal to the rate of flame propagation of the mixture at the instant combustion begins. At this point the cross-sectional area of the air-oil jet` is many times larger than the area at the base of the jet.- Conscquenth' the mixturccanfbe much more readily .ignited and combustion will maintainitself at this pointfwithout any a'ppreciablc'amount of bucking orv flickering. By employing a gas burner which entirely surrounds the jet of oil and air issuing from the oil burner, the gas flame thrown out from the tips .of the gas burner spreads in a substantially `horizontal sheet over the entire cross-'section of the jet of combustible oil and air mixture vissuing from theatomizing nozzle, igniting the mixture throughout the entire cross-section of the jet-rather than at-a few pointsin the periphery, as is now 'the common practice. In other words the ignition of the air-.oil jet according to the present invention is effected uniformly throughout :its entire cross-section at an elevation where the mixture is prepared t0 maintain its combustion vwithout any flickering back and forth, producing practicallynoiseless -conlbustion with a-smooth and -most desirable charac ter of flame. Moreover, because Combustion takes place in a. smooth and effective manner the. highest degree of eiciency in loo oil has reached a fine state of atomizationand has spread over a relatively large cross sect-ion. Intimately exposingthe finely atomized oil to the heat of the gas fire at this point gives the burning gas a better opportunity to further break up the oil spray and to completely vaporize the atomized oil, thereby producing efficient combustion without any possibility of carbon formation. In other words by igniting the atomized mixtures at the critical point at Which the velocity of the jet entering the furnace is substantially equal to the rate of flame propagation of the mixture, the hea-t from the source of ignition is most effective in gasifying the combustible air-oil mixture. l s previously indicated it is possible to adjust the present apparatus to give efficient and noiseless combustion when burning Widely varying grades of oil,rand the burner apparatus i s so constructed that the atomized air-oil mixture entering the furnace is completely ignited and v porized without at any time coming into con act withv It is not intended by the foregoing description to limit the pinvention to the use of air as an atomizing a" ent for the oil o r other liquid fuel, since o viously steam or i other'suitable atomizin agent for the liquid fuel may be employe without departmg: from the principle underlying the invention.

The inventionhaving been thus described what is claimed as new is:

lo 1. The method of burning liquid' fuel 1 which comprises jetting an atomized mixture of the fuel and air into a combustion chamber, and vaporizin and igniting the mixture substantially at t e point where the velocity of u the jet equals the rate of flame propagation of the mixture.

2. The method of burning fuel oils which comprises injecting' an atomized mixture of the oil and an atomizing agent into the combustion chamber of a furnace and throwing a sheet of gas flame transversely across the jet It a point at which'the velocity of the jet sub- Y stantiall equalsthe rateof flame propagation oft e mixture.

Il 3. The method of burning liquid fuels which comprises atomizing a )et of the fuel with air under pressure, throwing a sheet ofL y flame transversely across the path of the jet to ignite it at the 1point where the velocity of Il the )et substantia y equals the rate of flame propa ation of the atomized mixture, and

adjusting the ratio of air to fuel in the mixture to maintain substantially uniform and quiet combustion.

8l 4. The method of burning liquid fuels which comprises atomizing a jet of the fuel with air under pressure, throwing a sheet of llame transversely across the .path of the jet to ignite it at the point where the velocity of a the ]et substantially equals the rate of flame propagation of the atomized mixture, and adlustng the space separating the base of the ]et from the point of ignition in accordance with the type of fuel being su plied to maina tain substantially uniform an quiet combustion.

5. The method of burning liquid fuels which comprises injecting a )et of the fuel into a combustion chamber, admiXing air 5o with said fuel in amounts sufficient to support its combustion, and igniting the mixture substantially at the point Where the velocity of the 'et equals the rate of flame propagation of t e mixture.

55 In testimony whereof I aiiix my signature.

' ALBERT L. KLEES.

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