US2614618A

US2614618A - Air and fuel supply means for liquid fuel burners of the bowl type

Info

Publication number: US2614618A
Application number: US50312A
Authority: US
Inventors: Lee S Chadwick; Evans W Cheeseman; Arthur R Moore
Original assignee: Perfection Stove Co
Current assignee: Perfection Stove Co
Priority date: 1948-09-21
Filing date: 1948-09-21
Publication date: 1952-10-21
Anticipated expiration: 1969-10-21

Description

Oct. 2l, 1952 L. s. cHADwlcK ET AL 2,614,618

AIR AND FUEL SUPPLY MEANS FOR LIQUID FUEL BURNERS oF THE Bowl. TYPE 3 Sheets-Sheet 1 Filed sept. 21, 1948 l.. s. cHADwlcK ET AL 2,614,618 AIR AND FUEL SUPPLY MEANS FOR LIQUID FUEL BURNERS oF THE Bowl. TYPE Oct. Z1, 1952 s Sheets-sheet 2 Filed Sept. 2l, 1948 3 Sheets-Sheet 3 MEANS FOR LIQUID FUEL.

OWL. TYPE:

INVENTORl EVANS w. cnaesamnw i o r' n ggf L. S. CHADWICK ET AL BURNERS OF THE B AIR AND FUEL SUPPLY Oct. 21, 1952 Filed sept. 21. 1948 LEE 5. CHHDW1CK BY RRTHUR R- MOORE `lytically cracked fuels,

yburners that is Patented Oct. 21, 1952 s -VUNITED STATES YPATENT *l OFFICE' AIRAND FUEL SUPPLY MEANS Fon LIQUID ,i

FUEL BURNERS THE BOWL TYPE I .j Lee S. Chadwick, vShaker Heights, Evans t Cheeseman, Lakewood, and Arthur R. Moore,

Cleveland, vOh'iofassgnors to Perfection Stove Company, Cleveland, Ohio, a corporation of Application september' 21`,194s,se`ria1No. 50,312

12 claims. (o1. 15s- 91) the'bowl'or pot type, and more particularly to improved means for admitting fuel and air-there- Heretofore, with respect to burners ofthe above mentioned type, carbon deposit, and the accumulation of other` fuel residues, in andabout" the fuel inlet of thelbowl, have attended the operation of thevburners; and this, obviously, hask necessitated frequent cleaning, and occasional repair and replacement of the fuel inletl means.

This unfavorable condition, which is especially pronounced in the burning of the so'fcalled catadevelops at arrate into the size of the fire. AIn during Ylow versely proportionate other-words, it grows more rapidly or pilotf fire operation. ,s

We have discovered that, in order to successfully burn the beforementioned catalytically cracked orsimilar fuel in a bowl type burner, it is necessarylthat the fuel be maintained at arrelativelylow temperature during its passage from the fuel supply and metering meansjcornmon in the type of burner above referred to,to the point of its liberation withinvther bowl. However,L after its being liberated, the fuel vmust be rapidly transformed into a state suitable for combustion, which generallyV means that it must be converted from liquid to gas andimmediately mixed with a predeterminedamount of air. It is essential, on the other hand, lthat actual combustion take place relatively remote from the point where'the fuel is liberated so that the fuel discharge means or tip` of the fuel supply pipe will be maintained at acomparatively low temperature in order to prevent undesirable cracking of the fuel and the ensuing" deposit of carbon and residue in or upon said means or tip.

- and which is characterized by'additional'means It is, therefore, the lprimary object of our invention to provide, in a bowl type burner, means for supplying liquid fuel and air to the bowl in proper proportions and in a manner to bring about theA results above set forth, and which is equally effective at all stages of burner operation, frornlowor pilot both inclusive. l y It is'- anotherobject of the invention to provide means ofthe above-described character that insures eflicient burning of the fuel at all stages of burner operation.

Another object of the invention 4is to provide fuel and combustion air inlet means for bowl type so related to the region of lcoinbustion that the combustion air is preheatedy a limited amount before being discharged into the bowl. l Y

fire to high or maximum re,

l single wall tube with the 'radiation of heat, durf y ing .higher re conditions, Afrom the flame to the r:fuelspread over the bottom of the burner bowl.

posed peripherally of It is anotherobject of the invention to provide a liquid fuel burnerv of the type aforesaid including lan air housing about the burner bowl and wherein there are air admitting means'disthe bowl through which its interior communicates with that of the housing,

for conveying air to thefcentral'region of the bowl, said additional means beingso constructed and arranged as to effect a proper control and Ydistribution of the air, thereby to assure stable conditions -of combustion 'at all stages 'of re.

vA further object ofthe invention is-to provide a bowl type burnerincorporating means for delivering fuel and a proportional amount-of combustion air to an area within the bowl a suitable `distance above the bottom thereof and vin such manner that the fuel, as it is liberated'and drops to the bottom of the bowl, will be envelpedin the combustion ^air,-whereby, upon `vaporiaation andignition of the fuel, combustion will be'localvized Ato a given region of the'bottom of the Abowl in spaced relation to the pointof admission of 'the fuel.'

With the fuel-and air thus delivered to the burner bowl and :combustion localized as described, it is protected from abnormalconditions or disturbances, such as air currents or eddies caused within ythe bowl by down drafts in the chimney'to which the burner is connected,

or such aswould be caused by momentary interruptions inthe supply of fuel to the burner.

A still further and fundamental object of the 'invention is to provide a construction wherein` the fuel 'supply pipe is so vrelated lto the com. bustion airsupply means that said pipe is maintained at `a relativelylow temperature during burner operation,thereby toavoid the conditions conducive to carbon formation.

l The invention is susceptible to differentv embodiments, two being disclosed herein, characterized, respectively, by a single wall air vsupply tube, and by a double vwall air supply tube. 'The latter has the advantage of providing an insulating space between the inner and outer*` walls of the air supply tube which, obviously, maintains the incoming combustion-air at a lower temperature than would otherwise be the case; and as a consequence of this theoutside diameter of the double wall air supply tube may be less than'that of the single wall modification, under which circumstances-itwould interfere less than the larger Another object of the invention is to provide a dischargetip-l of `.novelcharacter for the fuelsupply pipe that will liberate the fuel in smaller droplets and with greater frequency than occurs when the conventional shaped tip is employed, and which..lat ter.isforrned bycutting or trimming thel dischargefend of the fuel supply pipe in a plane normal tothe axis of the tube in the immediate region of said end. Our improved tip l is especially advantageous when the fuel is fed at an extremely low rate, suc-h'as` for pilot -or low re. In this connection it may beeXplaine'd that when the fuel is fed in larger drops at relatively longY intervals, a fluctuating re lresults-that ,is

'. bottom w 1.21;

wall 20go ,th2;hQusing H ts over a cylindrical hard to control because offthediinculty ofsup--i l plying the requisite amount 'of combustion ain v under such circumstances.

Other objects will appearas we rproceed to describe the herein disclosed embodiments of the' invention and among which are convenience` of f assembly and disassembly, ready accessibility of the parts, and ease of fabrication,v

' In theaccompanying*drawings that form a part hereof and wherein like reference characters des- Aignate;like parts inthe different views, Fig, A1

,but lessxcomprehensive. than Fig. 1, showing an- .other. formfof theinvention; Figs. 5 and 6 are .sectionalfdetails on the.respective lines 5 5 and @+6 of Fig, 4; Fig.- 5 :being on av somewhat enlarged scale, and Fig. lisa View, similar to Fig. 4,

v.showing the inner' air tube and the` fuel supply pipe partially withdrawn` from the assembly.-

Wegshall first describe the simpler -form of our invention; Aillustrated inFigs; 1, 2 and Sywherein asinglewall air supply tube Iv is shown as passing diametrically through the burner bowl, the latter being Ydesignated generally by the reference letteryB. The burner -bowl is shown kas fabricatedffrom sheet .metalparts includingy a cylindrical peripheral wall 2, to the respective upper and lower ends'of which are suitably connected, as by welding, an annular top wall 3 and a circular bottom wall il.` Shown asl connected by a seam 5 to the top wall 3 about therlarge central opening thereof is an .upwardly divergent perforated throatmem- `ber 6 which has its outer'edge portion overlying -and connected to an annular, stepped member 1. This member is -detachably connected by fastening means 8 to the lbottomwall 9 of a'structure shown 'in `broken lines and which` includesvertical wall portions Ill. Said structure encloses a combustion chamber or space C that communicates with the interior of the burner bowl through a large openingin the bottom wall 9 andthe passage wherewith it registers` that is surrounded and thus defined by thel steppedy member?, throat member 6,

andl top wall 3. Said top wall 3 and member'l are frigidly connected together at circumferen-l tially spaced points by ties I5 in accordance with prior practice. i

vThe central portion of the bottom wall 4 is depressed to provide an oilsurnp of considerable areaand, at its center,- said wall is shown as `formed to provide a shallow cup I6 that is preferably occupied by a body or vdisc of pervious re fractory material. A material found especially suitableV for our Ipurpose is a relatively coarse For descriptive purposes l grained sinteredmetal. y the,y aforesaid body orv disc of Apcrvous material,

. 4 or, in its absence, the interior of the cup I6, will be referred to as the target I8.

Enclosing the burner bowl B is a housing that is designated generallyby the reference letter H andthatfconsist's of afcylindricaligperipheral wall 2U andl a slightly'dished'circularbottom wall 2I. 'I he bottom wall has a relatively large central opening surrounded by a depending flange 22, a'nd-tted `overthelatter is the outwardly flanged upperend of a relatively shallow sheet metal cup 23, s aid cup. being fastened, as by welding, to the vThe upper end of the peripheral v.portion oflfthe vpreviously mentioned annular stepped member 'Lithe overlying portions of said wall and. member. being welded or otherwise secured together. The peripheral wall of the housing H is radially spaced from the peripheral wall 2 of the burner bowl B to provide an air space that surrounds the burner Ybowl and communicateswithits interior through perforations 2a in the wall 2. vThe air space S also communicates with the combustion chamber or space C through the perforations 6a of the throat member Bjand through an aperture in thel member l, over which aperture is an air director or hoody 26. This latter fea-tureconstitutes no part of my invention, but is disclosed and claimed in the` applicationof Marc Resek, et al., Serial No. 789,052, filed December 1 1947.

.with the aii` supply'tube I, and projecting inwardly through said hole is atubular extension I@ through which the outlet of the scroll casing of a centrifugal fan or blower F` hascommunicative connection with the air supply tube I.v For present purposes, said extension and tube may be regarded as a unit, and the samemaybe described as extending inwardlythrough the openingin the wall 20 and diametrically through the burner bowl I and as having its end. portions sealed in holesinl opposed parts of the wall 2. -The end of the air supply tube remote from the vfan or blower F opens into theair'space S. Said fan orblower is operated by an electricmotor M that is shown as attached to the side of the beforementioned scroll casing.

Opposite the inner or discharge end of the air supply tube I, the wall 20 of thehousing H is provided with an opening that is normally closed by a plate 36. The plate is` shown as attached to said wall by screws 3l, and as having a central aperture 38through which a fuel supply pipe isiextended inwardly, thev pipe continuing within the air supply tube I to about the longil ported by a member I that may a convenient part of the apparatus.

substantially semi-cylindrical socket portion 46 wherein the -pipe rests, said socket portion desirably embracing something more than half the pipe so that the pipe will snap into the socket when fully depressed. At its outer end, thek fuel supply pipe has connection, through a' coupling 48with a tubular outlet 49 of' a liquid fuely supply and control'means 50. This means desirably consists of a so-called constant level valve, an article well known to those familiar with the subject to which the invention relates. The liquid fuel supply and control meansA 50 is shownvas supbe attached to In order to avoid flooding of the burnerzbowl, and to provide for a definite maximum lliquid level therein, the depressed portion of the bottom wall 4 of the bowl is provided with an overflow opening 5.5, from which a pipe 56 leads to Aa vessel 51. This vessel encloses a float 5B that has operative connection, through a rod 59, with trip mechanism of the liquid fuel supply and control means 50., Such trip mechanism is a part of the previously mentioned well known constant level valve that is employedv in the present instance as the liquid fuel supply and control means. When liquid fuel rises within the burner bowl to an abnormal height, and the excess escapes through the overflow opening 55, said excess fuel drains tothe vessel 51 through the pipe 56 and lifts the float w5,3 thereby to operate the aforesaid trip y mechanismand stop theiiowk of oil through the pipe 46. Communicating with the lowest part of the pipe 56 is a drain valve 60 through which the vessel 51 and pipe 56 may be emptied of liquid fuel at the time of resetting the trip mechanism. This restores the apparatus to condition for normal operation.

When the apparatus is in operation, oil will be delivered to the burner bowl through vthe pipe 40 at a rate depending uponthe adjustment of the liquid fuel supply and control means 5G. By'this means the fuel may be fed at different rates to produce low or pilot lire, intermediate fire, and high or maximum re. In any event, the fuel drops from the discharge end or tip of the tube 40 onto the target I8. It will be understood, of course, that during operation of the apparatus, the motor M is energized and drives the fan orvblower F which impels air through the 4tube I into the space S and, through the aperture 42 of said tube, into the lower portion of the burner bowl. The air entering the bowl through the aperture 42 is more or less in the form of a columnr that is projected toward the target I8 about the fuel that drops from the pipe 4D. The burner may be lighted by any suitable means, as by a burning taper or the like introduced through the lighting and cleanout opening 36. Very shortly after` the burner is lighted, the target I8 and the surrounding portion of the bottom wall of the burnerbowl become sufficiently heated to vaporize the oil. The vapors immediately commingle with the air in sufficient amount to render combustion subthat is projected downwardly through the aperture 42 andthe mixture burns within the bowl.`

stantially complete, enters through the perfoi'ations 2i in the peripheral wall of the bowl. Under these conditions the products escape through the open top of the bowl into the combustion space or chamber C. When the fuel supply is increased by an appropriate adjustment of the means v50 (whether it be accomplished-manually or by thermostatic means, in which latter event the/apparatus would be equipped with an automatic control system .of usual character) the .droppingof the oil quickens and the volume of the irein-Y creases. Under these circumstances theair entering through the aperture 42 supplies only a part of the primary air, the balance vvbeing supplied through the perforations 2a of the wall 2. During high or maximum fire, substantially the entire capacity of the perforations 2a is needed to supply the requisite amount of primary air, wherefore a rich mixture fills the bowl and, as it rises through the throat member 6, it receives secondary air through the perforations 6a and is thus conditioned for combustion within the combustion space or chamber C.

During all stages of operation, the discharge end or tip and adjacent portion of the fuel supply pipe 4D is maintained "relatively cool by the surrounding column of air, while the air supply tube itself is kept at a relatively low temperature by the air stream that is constantly flowing through it. Also, the region of said tube above the target I8 is protected from the intense heat of vcombustion by the presence of the air issuing through the aperture 42. As a consequence of the favorable temperature conditions just described, carbon deposit and the accumulation of other fuel residues within or upon the tip ofthe fuel pipe is prevented, and deterioration of the air supply tube is avoided. While we have referred to relatively low` temperatures of the air supply tube andfuel supply pipe, it will be understood that operating temperatures within the bowl will be high enough to cause the air flowing through the air supply tube to be preheated to a desirable degree.

What we at present consider the preferred form of our invention is illustrated in Figs. 4 to 7, where the air supply tube is of double wall construction, and the oil supply pipe is formed with a unique tip. This modification we shall now describe.

The air supply tube, designated generally by the numeral IUD', consists of an inner cylindrical wall IIlI and an outer cylindrical wallr |02 that are maintained in radially spaced, and desirably'concentric, relation to each other by collars |03 and |04 that are substantially Z-shaped in cross section. The llarger ends of these collars fit within the ends of the outer cylindrical wall E02, while their smaller ends iit about the adjacent-portions n of the inner wall. lill. The larger end'of collar ID3 is welded or otherwise secured to the adjacent end of said outer wall I 62, While the smaller end of collar E64 is similarly fastened to the inner wall IIlI. The reverse ends of said collars are unxed with respect yto the walls wherewith they cooperate. The ends of the outer wall |02 are projected through holes of appropriate size in diametrically opposed portions of the peripheral wall 2 of the burner bowl, and are welded or otherwise fastened to said wall. The portion ofthe peripheral wall 2i) of the housing H that is nearest the collarzI03 is provided with an opening shown as surrounded by a flange I lll that is axially -alignedwith vsaidcollar and is substantially equal in inside diameter to .the outside diameter of the Walll Alsolv the: portion: of said housing wall 2|! that is adjacent the .collar i'iliis provided with anfopenng H l aligned with saidcoll'ar and that is'somewhatgreater in `dituneter thanthe larger endl thereof. This lattero'pening'lis.adapted to be close'diby a plate ||2:.'tha`t is shown as fastened tothe Wall 2B. by .screws When .the parts. of thefassembly. arein normal-relation, as shownL in Fig.: 4;'the.inner: wall IDI projects a'substantial distance-through .the collar. 103,1" across the air space:S and intoitlieange H8; Shown engaged over theaan-ge. Hliis `the outlet connection ofthe scroll casing oft-liefern or blower F. Supported within and permanentlyzconnected. tothe cylindrical wall ||l|, through hangers H5, is. a' fuel supply pipe |2|3` `that enters the housing through afh'ole |2| in the previously Vmentioned plate. i i2. Itrwillbe understood that the outer end of the fueli supply pipe l is adapted z to be connected, throughia coupling |22,` with a fuel supply and control means, such as that 'shown at 5U .in Fig. 1.' The'inner end ofthe fuel .supplypipe |20v is curved downwardly and terminates in a unique oilfeeding tip ithat is formed by cutting away th'eisides'ofthe. tube atan angle, as best shown inzlig. 5,. tov formA two pointed, laterally curved beaksxthatiaresthen iiattened and: pressed toward each other to dispose ther'nfin slightly'spaced parallelrelaitionf.` The vtip iiprojects through an aperture|28in the inner wall |534 that registers withalarger aperture |29in' the outer wall |92. A lug-430i extends radiallyrfrom'the larger'end of the-collary lil'lliand, when kthe parts are in normal relation, said lug occupies a notch' |3| .in the adjacent end of thewall |82. Thus, vided-v f'or positioningV the' inner wall lili inr such relation to the: fixedV outer wall H32V that the aforesaid apertures.. |28'and'l29- are in register, and theftip is directly above the target I8.

In general, the operation ofV the Vpresent 'form of` thefinvention is the same as that-of 'the `form previously described. However, in the present case, at a-correspondingrate of flow, the fuel is delivered in smaller drops and with greater frequency than'in the former case. This result is due tothe difference in the discharge end or tip of the fuel supply pipe, and it contributes to a more even nre, a more uniform vaporization of the fuel, anda better mixture of primary air with the vapors. Also, experience has shown that there is less tendency for carbon and other fuel residues to form or accumulate in or upon a tip of the style shown in Figs. 4 and 5.

Furthermore, because of the double wall construction of the air supply tube |00, with its insulating air space, thetemperature of the combustion air is better' controlled; and a further advantage is that this construction admits of a smaller external diameter than the single wall tube; thereby afording a larger vaporizing area during higher nre, as already pointed out.

It is also evident from the construction at present under consideration that the inner and outer walls of the air` supply tube are capable of independent elongation and contraction. Therefore, the outer wall |92, which has its ends fase tened tothe peripheral wall 2 of the burner bowl, is Vfree to expand and contract with the latter wall under temperature-changesand independently of the inner wall IIJ which is kept relatively cool by the air flowing through it. Accordingly, undesirablestresses are not so likely to occur in the double wall air tubev construction as in the single tubeembodiment where such stresses in the structure vmight resultrfrom" the'difference in tem- 8i perature between the tube and theburner'bowl wallZ rto which saidy tube is rigidly connected.

InV Fig. 7 'we have shown ho-w the inner cylin, drical wallV {l-l may be Withdrawn from the assemf bly orl replaced, when the plate ||2 is removed from the opening of the wall 2D.

Having thus described our invention, what we claim is:

1. Inliquid/fuel burning apparatus, the combination of a burner bowl including aperipheral Wallya housing enclosing, saidvbowl and having a peripheral wall spaced from the` corresponding wall of the bowl, an'air supply tube extendinginwardly through the peripheral Wall of the housing and entirely through the bowl and openingY at its inner end into the space between said walls,'the tube having an aperture in its lower side through which the interior of the tube communicates with that of the bowl, and a fuelr supply pipe projecting into the air supply tube and. arranged with its discharge end above said aperture.

2. In liquid fuel burning apparatus, the combination of a burner bowl including a peripheral Wall, a housing enclosing said bowl and having a peripheral wall spaced from the corresponding wall of the bowl, an air supply tube extending inwardly through the peripheral wall of the housing and diametrically through the bowl and opening at'its inner end into the space between said walls, vthe tube having an aperture in its lower side through which it communicates with the bowl, and a fuel supply pipe projectingV in# wardly through the peripheral wall of the hous- Ying substantially diametrically opposite the entrance of the air supply tube through said wall and continuing into the air supply tube and having its inner end turned downwardly and arranged substantially within the area of said aperture.

3. In liquid fuel burning apparatus, the combination of a burner bowl including a peripheral wall and a bottom wall, a housing enclosing said bowl and having walls spaced from the peripheral and bottom wallsof the bowl, an air supply tube extending inwardly through the peripheral wall ofthe housing and diametrically and horizontally through the bowl and opening at its inner end into the space between the peripheral walls of the bowl and housing, said tube being spaced a substantial distance above the bottom wall of the bowl and having an aperture in its'lower side substantially coincident with the vertical axis o f the bowl, and a fuel supply pipe projecting through the peripheral wall of the housing and into the air supply tube through the inner end thereof and having its discharge end turned downwardly'in alignment with said aperture, the bottom wall'of the bowl having a central depresi sion.

4. The combination of elements dened by 'claim l3, plus: a target consisting of a body of pervious refractory material occupying said depression.

5.v In liquid fuel burning apparatus, the combination of arburner bowl including a peripheral wall and a bottom wall, a housing enclosing said bowl and having a peripheral wall spaced from the corresponding wall of the bowl, substantially dia-metrically opposite portions of the peripheral Walls of the bowl and housing having substantially axially aligned openings, an air supply tube extending inwardly through one of the'openings of the housing wall and through the burner bowl and khaving its inner end Xed within the Opening-of.v the burner bowl wall' at the side thereof line bottom wan "of l .6. lInliquid fuel remote froinithatgthrough whichithe air supply tube enters the housing, the air supply tube Ahaving Vanaperture in its loweriside at 'about the ,-vfrtcal center of y rrivabiyjattached to theV peripheral waiior the icusingpver the opening l inner'end of .the air ing a hole, an oil supply pipe extendingV inwardly Y '.throughfsaid holeand into the air supply ,tube

the'rein adjacent the supply tube, `said plate hav- `"and havingy its inner end turned` downwardly and alignedv/lithl the aperture 'of the y'air supply' tube,

the bowl'having a depression' inv vertical alignment with said aperture, and a target consistingof abodyl of -pervious refractory material occupying said depression.

burning apparatus, the comybinationof elements defined ,by claim 5, plus: a

tube surrounding and radially spaced `from the air supply tube within the burner bowl and hav- Y ling an aperture registering with that of said air'` supply tube.

7. In liquid fuel burning apparatus, the combination of a burner bowl, an air supply tube extending substantially horizontally into the bowl and having an aperture through which it communicates with the interior of the bowl, said aperture being located on the underside of the tube, and a fuel supply'pipe projecting into the air supply tube and arranged with its discharge tip substantially within the area of said aperture, said tip being characterized by opposed with the interiorof the bowl, said aperture being located on the under side of the tube, a fuel supply pipe projecting into the air supply tube and arranged with its discharge end substantially within the area of said aperture, said air supply tube being spaced a substantial distance above the bottom of the bowl, and a heat insulator in shielding relation to the air supply tube.

9. In liquid vfuel burning apparatus, the combination of a burner bowl including a peripheral wall having substantially diametrically opposed openings spaced a substantial distance above the bottom of the bowl, a tube extending through the bowl and'having its ends fixed in said openings, a housing enclosing the burner' bowl and having a peripheral wall spaced from the corresponding wall of the bowl and provided with openings aligned with those in the peripheral wall of the bowl, an air supply tube of smaller diameter than the formertube extending inwardly through one of said openings in the peripheral wall of the housing and axially through the aforesaid tube and terminating adjacent the end of the first mentioned tube remote from that through which the air tube enters said first mentioned tube, means supporting and spacing the air supply tube from the first mentioned tube, the air supply tube and the rst mentioned tube lhaving registering apertures on their lower sides that are substantially central of the burner bowl, and a liquid fuel supply tube entering through the other opening of the peripheral wall of the housing and ,projecting into theair, supply tube and Y having its innen, discharge .s end; ,turnedy ldownyply tube and fitting within wardly kin alignment with the-j aforesaid apertures. l

1G. In

tial distance above-,thebottomwall ofthe bowl,

a tube disposedv across the burner bowl and hav- A ringiits ends fixedwithin said openings, ahousing enclosing the .burner bowl and-having aL peripheral wall spaced from the correspondingH wall of the bowl, said .peripheral havingfopeningsjthat are substantially in axial alignment with'theaforesaid tube, an air supply tube extending axially through the aforesaid tube and having one of =its `ends within one of the openings of the vperipheral wall of the Vhousing and its other end substantially intheplane-,of the corresponding end of` their lower sides, collars embracing the air supthe ends of the first mentioned tube, and a fuel supply pipe extending through the other opening in the peripheral wall of the housing and into the air supply tube and having its inner end turned downwardly and aligned with the apertures of said tubes.

1l. In liquid fuel burning apparatus, the combination of a burner bowl including a peripheral wall and a bottom wall,V substantially diametrically opposed portions of said peripheral wall having openings that are spaced a substantial distance above the'bottom wall of the bowl, a tube disposed across the burner bowl and having its ends fixed within 'said openings, a housing enclosing the burner bowl and having a peripheral wall spaced from the corresponding wall of the bowl, said peripheral wall ofthe housing having openings that are substantially in axialalignment with the aforesaid tube, one of said openings being of a diameter at least as great as that of the aforesaid tube and the other opening being of somewhat lesser diameter, an outwardlyextending flange surrounding the smaller opening, an air 'supply tube extending axially*V through the aforesaid tube and having oneA of its ends supported within the beforementioned flange and its other end adjacent the corresponding end of the rst mentioned tube,

said tubes having registering apertures in their lower sides that are substantially central of the burner bowl, collars embracing the air supply tube and fitting within the ends of the rst mentioned tube, the collar nearest the end of the air supply tube that occupies said flange being fastened to thev rst mentioned tube, andthe other collar being fastened to the air supply tube, whereby the air supply tube, with the last mentioned collar attached, may be slid free of the other collar and withdrawn from the first mentioned tube through the larger opening in the peripheral wallof the housing, a plate detachably connected to said housing wall over said larger opening, the plate having a hole, and a fuel supply pipe extending through said'hole and into the air supply tube and having its inner end turned downwardly and aligned with the apertures of said tubes.

l2. In liquid fuel burning apparatus, the combination of a burner bowl, an air supply tube leading substantially `horizontally into the bowl a distance above the bottom thereof and having an raperture in its under side through which it i liquid fuel 'f burningv e apparatus, the f combination of a burnerbowl includinggaperiphwall of the housingA the firstk mentioned tube, said tubes having registering apertures in v' vcommuhicates with the interior of the Yhema fuel supply 'pipe extending in'to the air supply tube and arranged With its discharge nd in spaced relation to the perimeter of said aperture so' that fuel discharged from the pipe will drop freely into' che `bowleiw'eloped by air entering the bowl through said aperture', and an insulating 'structure inludinga tube entirely'enc'asing and radially spacedfrom the o'tin o'f the air` 'supply tubewithin the bowl,--and end means separating thespace .between said tubes from the interior offthe boWLth second xnn'ti'oned tube having Eny 'aperturein' `register Withithat of the .air supj ply tube.-

s. OHADWICK. EVANS W. CHEESEMAN. -ARTHUR R. MOORE.

i vEEFEEMBES CITED "'l'ijfl'low'ing'* references are f record in the f'12 UNITED STATES' PATENTS Number l5 Number Name Da't Petty gMay, 1910 schaurnann Mar.' 31, 1925 Littl Dec. 22, 1925 Blake Dec. 27, 1927 4Grant Dec. 8, r1931 Poore Deaf@ 1932 Qannon O t. 31, 1333 *Ramsey Oct. 1,5, 1940 Keating June 2 4, V1941 Johnston Jan. 26, 1943 FOREIGN PATENTS