US2640530A - Pot type burner for liquid fuel - Google Patents

Description

June 2, 1953 Aw..c. ROBERTS POT TYPE BURNER FOR LIQUID FUEL 2 Sheets-Sheet l Filed Feb. 12. 1948 FIG. 2

JNVENTOR. W- C. ROBERTS FIG. 3

ATTORNEY June 2, 1953 w. c. ROBERTS 2,640,530

` POT TYPE BURNER FoR LIQUID FUEL Filed Feb. 12, 194e 2' sheets-sheet 2 INVENTOR.

' W- C. ROBERTS ATTORNEY Patented June 2, 1953- POT TYPE BURNER FOR LIQUID FUEL William C. Roberts, Detroit, Mich., assignor to Bone Tool & `Gauge Company, Detroit, Mich., a

corporation of Michigan l Application February 12, 1948, Serial No.7,776 l 7 Claims.

This invention relates to burners `and Y more particularly to an improved pot type burner for liquid fuel.

Heretofore many .burners of this .type have been designed and manufactured but these burners have been relatively inefficient, mainly due to improper introduction of the primary air-necessary for eicient combustion, incomplete and slow vaporization of the liquid fuel and the formation of carbon deposits on the'passage or passages through which the fuel iiows into the combustion chamber. l t It is'therefore an object of this invention to provide a. pot type liquid fuel burner of relatively simple and economical construction comprising only two major parts preferably castings.

` It is a further object of this invention to provide a liquid fuel burner in which the fuel inlet passage is shielded from the actual combustion chamber in order to prevent formation of carbon deposits therein and in which the fuel is` introduced into the combustion chamber throughl a plurality of passages, which passages may also serve for the introduction of primary air,I thus.

It is a further object of this invention'to provide a liquid fuel burner in which'the-fuel is supplied to the combustion chamber in a relatively thin film spread over a large ,area which permits the yfuel to be quickly heated to a relatively high temperature, thus increasing the rate of vaporization.

It is a further object .of the invention to provide a liquid fuel burner kin which the primary air passages also serve to introduce fuel into the combustion chamber and whereby any formation of carbon on such passages is removed by the action ofthe air blast.

It is a further object of this invention to provide a novel method of supplying fuel toa. pot type burner whereby relatively fast and complete vaporization is obtained resulting in vsubstantially complete and highly efficient combustion.

It is a further object of this invention to pro'- vide a modified form of liquid fuel burner vin which a liquid fuel vaporizing chamber located adjacent the lower portion of the sides of the combustion chamber serves to vaporize the fuel prior to its introduction to the combustion chamber, the structure forming the vaporizing chamber also serving to prevent undesirable burning or flames outside the combustion chamber. y

It is another object of this invention to provide' 2 r a still further modified form of liquid fuel burner in which a separate vaporizing compartment located below the combustion chamber serves to vaporize the fuel prior to its introduction to the combustion chamber through apertures in the bottom thereof.

Further objects and advantages of the invention will be apparent from the following description taken in conjunction with the accompanying drawings, wherein: t,

Fig. 1 is a sectional view in elevation showing the burner of this invention incorporated with a conventional fuel and forced draft supply; t

Fig. 2, a. partial perspective View ofthe burner and combustion chamber with the parts broken away for greater clarity; Y Fig. 3, an elevational view in section taken on the line 3--3 of Fig. 1; I

Fig. 4, a, sectional view in elevation taken on the line 4-4 of Fig. l;l t

Fig. 5, a partial perspective view of a. modified form of the invention with parts broken away for greater clarity;

Fig. 6, an elevational view in section showing the modified burner of Fig. 5; and, y

Fig. 7, a sectionalview of a furthermodied form of the invention.v

With continued 4reference, toI the drawings," there is shown 'in Fig. 1 a liquid fuelburner` II): secured in an aperture II in the top rportion of an air duct I2 by rivets or other conventionalfas-A tening means I3. Air duct I2 may be formed of sheet metal or other appropriate material and isv securedto a fire wall or shield I4 which may either compriseone wall of va furnace or may be` utilized as a closure for anV openingin a furnace,A through which the burner I0 is introduced fori-I instalation. Also secured to the wail I4 h outer surface thereof is a yblower I 5 and -a. .bar4 metric type fuel supply means I6, air from;,the

blower I5 being' introduced through th duct I3@ to the burner Il).v 'i

As best shown in Fig. 2, the bur, prises Ian outer receptacle I'I ha bottom surface I8, upstanding end walls 20. The receptacleJ.

lof the plate 22 adjacent the opening 23 are flanges `2li and 26, forming the side and end walls respectively of the lcombustion chamber. It is understood that if a circular burner were used, the combustion chamber would have a continuo-us rcircular wall. In the preferred form of the invention shown in Fig. 2, the opposed flanges 24 are provided with a plurality of slots 25 extending from the 'bottom'of the flangeslto apoint slightly below thelower surfaceof the plate 22'. The slots 25 provide vertical passageways extending from the inner bottom surface I8 of the receptacle I7' for the introduction of lprimaryfaiifY t'ofthejrcom-r bustion chamber formed by the opening 23 and the anges 24. As may be Lseen:fronr'anjinspec'A` tion of Figs. 1, 3 and 4 thepriinary air isfintroey duced through the duct I2 and flows between the lower surface of plate 22 anditheiiupper'edges-22K lof the receptacle I'I into the space between flanges 24 and the side Walls IS of the receptacle' I'I thence through the -passageways 25 into the combustion chamber.`

Fl'ang'es- 2@ which' form the end wallsA of" the combustionchamber are integral withv side flanges1-24butf the flanges Zlare -imperforate'and contact the innerI bottomsurfaceofthe receptacle II. In order to Iproperly loca-te plate'ztogether With= itsdepending-v flangesin the receptacle I1 thefbottomsurface' thereof maybe vprovided with upstanding lugs ZT' appropriately positioned'l to 'contact the lower inner surfacesoff the'flanges y24f and zf'iniorder to prevent movement ofplate :225 and itsdependingflanges relative to the re- Iceptacle I1'. Platev2-2f and receptacle IT are secured together by' screw threaded fastening rneansZ extending throughapertures 29; in the Yplate 22 and engaging screw threadedv lugs or -b'ossesf 30 formed on the-outersurface off receptacle II.

Fuel'issuppl-iedto-the burner I llthrough ac'on.- 'duit 3l from the supply IB and is` introducedito the receptacle II through' aperture' 3 2" in' the :end wall20for in thecase'of a circular burner 'the' aperture 32 would be located adjacentthe" junc- .ture-off the circula-r side' wall'with'the `inner'botf tom surface ofthe' receptacle. Fuel thus'ows through theapert'ure' 3521' and into'theispa'ce 33 abetween the end wall 20 of-'the'recepta'cle' IIrand" the ir'nperforatel end`- flange 26" depending from plate 2-2-2 Fronrspace' 33 the" fuel' flows around l rapidly heated` and' will tend to vaporize ahnosty immediately'on contacting this surface. Vapor-v ization' of' thefuel is. further assistedl and accelerate'diby` theflowof" air through the slots. 25 Whiclitends to 'agltate' the surface of 'theiowing fuel,1 this action materially` hastening vaporiza.- tion.

It will thus be seen that bythis structure there hasbeen'provideda means for introducing fuel. tothe combustion' chamber' of" ai burner over a*- Wide area andi in a' relatively" thin filmas contrasted to prior' methods of introducing'fel into 4. a static pool wherein heating of the fuel proceeds at a relatively slow rate and air flow thereover has little effect on vaporization resulting in the extremely low burner efficiency common in this type of burner. The burner of this invention, however, by the above described features, provides for extremely rapid vaporization, practically. complete combustion and resulting burner eflciency of 20 to' 30 percent highe'rthan previous commercial pot type burners.

The eciency of the burner is also increased by the structure Which provides for the introduction: ofV primary air in vertical streams through theslots 25.which results in a better disn persion' ofthe'fuellvapor through the air introducedlintothe.combustion chamber, which dispersion as is commonly known in the art results i111' higher" burner'. efficiency.

Itis to. be noted that the fuel inlet 32 is completely shielded from the combustion chamber proper by the depending flange 2B which precludes any carbon deposit' forming on' the'. fuel inletl 32 whichv would" tend' to vrestrict the' flow 'of fuel therethrough. Any carbon deposit which tends` to form" on theiedges'offslots 25"is'r'em'oved by the' air blastl passing through these slots, which' further contributes' to' burner' eiiiciency since'the' fuelr flow rate 'is thus' maintained.'A subst'antis'illy constant throughout'v the' life of the burner. This feature' also precludes' the` neces'- sity for'frequent cleaning" of the'burner..

In utilizing the principles describedabove in a circular or polygonal shape burner; itisic.on' templated that the slots' 25' would extend' substantially around'V theA circumference of' the depen'ding flange with a portion" thereof-` opposite the fuel" inlet to. the receptacle' being 'imperforat'e inl order to 'shield the inlet from'. the i combustion chamber proper as described"v above'.

This invention; in'addition tothe structurev described above, alsoi contemplatesan' improved and'v novel' method of introducing 'fuel' into" a p ot type' burner insuch a manner` that'thefuel is distributed in a relatively'tnin' film over a' com#- p'aratively large' surface in'order to obtainrapid and' complete vap'orization' thereof. and as a' further feature this fuel is' introduced through the same openings throughV which the' primary airis introduced, thus resultingjin theair now materially'assisting in the vaporization and.. dispersion'of'the'fuelivapor'through the air. This novel'method of fuel introduction"andvaporization results' in very.'high efficiencies for this type of'burner;

The modified form ofthe burner Ibest shown" Figs: 5: and' 6' is'simila'r' in mosti respects to the' burner abovev described with the exception that" the receptacle IT is'. provided on the inner' walls thereof with an' inwardly' extendingV flange 3E: The flange' 311" is spaced'above the bottomIS" of the receptacle. Il to provide inA conjunction witlisidev walls' I9, end'walls'2ll, flanges 24'and 26, and" bottomv I8" a vaporizing chamber. 35. Flange 3d extends throughout the inner surface of the receptacle IT the inneredge 34"' thereof being in intimate contactl with the outer walls of flanges 2H' and 2. th'us providing in effect a chamber extending aroundr the entire innersurface'tliereof Als above described; liquid fuel'. is introduced through conduit' 3I andfuel inlet 32to the space. 33 between the wall`2ll anddependingiiange 26'.' whereuponthis" fuel` willl w around the ends.. of `ange 25. and' partially, fillltliespacabelow the: inwardly extending. flange. 3K Prior. to ignition of the burner the liquid fuel will of course flow from the space 35 through slots 25 into thecombustion chamber but shortly `after the burner is ignited sufficient heat will be produced in the bottom I8 and depending flanges 24 and 26 to completely vaporize theliquid fuel in the space 35. This results in fuel vapor rather than liquid fuel being introduced to the combustion chamber through slots 25 thus resultingin increased efficiency of the burner. l f

Inwardly extending flanges 34also provide the additional functions of shielding or isolating the space thereabove between side walls I9 and depending flanges 24 from the fuel supply, thus preventing undesirable burning or flame in this space which would be dangerous and also reduce burner elciency.

It is of course obvious that inwardly extending flange 34 may be formed integral with the walls of receptacle |1 or may be formed as a separate member and secured to the wall of this receptacle by welding or other convenient fastening means. The principle above described inconnection with the modicationof Figs. 5 and 6 may also be easily applied to a conventional pot type burner comprising, as shown in Fig. 7, a combustion chamber defined by a circular or other conveniently shaped side wall 36 and a bottom 31. In the prior structures the bottom 31 was usually imperforate with liquid fuel being supplied thereto to form a static pool, the fuel vapors arising.

therefrom burning slightly above the surface of the pool. It was also common practice to provide the wall 36 with primary air inlets in the form of apertures 38.`

In applying applicants invention to this structure, the bottom 31 is provided with a series of apertures 39 preferably formed in a single row slightly spaced from the outer periphery of the bottom although it is of course obvious that these apertures 39 may alsoform other patterns rather than a singlecircular row. Attached to the bottom 3,1 adjacent the side wall 3B is a receptacle 40 forming a chamber 4| closed atthe top by a bottom 31 and communicating with the combustion 4chamber through apertures 39. Liquid fuel is supplied to the chamber 4| by a conduit 42, the level in the chamber 4| being maintained by any convenient means such as a barometric feed.

Inl the operation of this form of the invention liquid fuel is supplied to the chamber 4| in sufficient quantity to flow through apertures 39 onto the bottom 31 whereupon the fuel is ignited. As soon as sufficient heat is developed in the combustion chamber this will be radiated to the chamber 4| from theY bottom 31 thus vaporiz'ing the fuel in chamber 4|, the vapors then being introduced to the combustionv chamber through apertures 39. This action results in the fuel supply to the combustion chamber being in the form of vapor only which of course results in a relatively high burner efciency as compared to burner efficiency when fuel is supplied to the combustion chamber inliquid form.

It has been found in .practice that sufficient heaty is developed both in the form `illustrated in Figs. 5 and 6 and in the form shown in Fig. '7 to vaporize the fuel in the vaporizing chamber to such an extent that vapor only is supplied to the combustion chamber, such vaporization being at a rapid enough rate to insure that no liquid fuel will :dow to the combustion chamber.

The above described methods may be conveniently applied to existing pot type burners and the burners described herein incorporating these methodsv may be conveniently applied toexisting furnaces or may be incorporated as. a built-in unitin new furnaces It is apparent that there is provided by this invention very simple and efficient liquid fuel burners which are economical to manufacture and in which maintainence and repair costs are kept to a minimum. l

It will be obvious to those skilled in the art that various changes may be made in the invention without departing from the spirit and scope thereof and therefore. the invention is not limited by that which is shown in the drawings and described in the-specification but only as indicated in the appended claims.

What is claimed is:

1. A burner for liquid fuelcomprising an open top receptacle having an inner bottom surface, imperforate side .and end walls, a fuel inlet in one of said end walls, a plate spaced -above the upper edges of saidwalls, a central opening in said plate, side and end flanges depending from said plate adjacent said opening forming .side and end walls deilning a combustion chamber, said flanges extending downwardly in spaced relation to said side and end walls and into intimate contact with the inner bottom surface of said receptacle, relatively narrow vertical slots in said side flanges extending from the bottom thereof to points adjacent the lower surface of said plate, said end flanges being imperforate and one said flange serving to shield said fuel inlet from said combustion chamber thus preventing the formation of carbon deposits in said inlet, said fuel being introduced to said combustion chamber in a relatively thin Illm through the lower portions of said slots, the heated bottom surface of said receptacle together with the air ilowing through said slots serving to completely vaporize said fuel thus complete combustion thereof.

2. A burner for liquid fuel comprising an open top receptacle having an inner bottom` surface, imperforate side and end walls, a fuel inlet in one of said end wallsy a plate spaced above they upper edges of said Walls, a central opening in said plate, side and end flanges depending from said plate adjacent said opening forming side and end walls defining a combustion chamber, said flanges extending downwardly in spaced relation to said side and end walls and into intimate contact with the inner bottom surface of said receptacle, apertures in said side flanges, said end flanges being imperforate and one said flange serving to shield said fuel inlet from said combustion chamber, thus preventing the formation of carbon deposits in said inlet, said fuel being introduced tosaid combustion chamber in a relatively thin film through said aperture, the heated bottom surface of said receptacle together with the air flowing through said aperturesserving to completely vaporize said fuel thus producing substantially complete combustion thereof.

3. A burner for liquid fuel comprising a receptacle having a relatively flat inner bottom surface and an outer wall, a fuel inlet in said outer wall, a combustion chamber within said receptacle defined by an inner side wall extending above said outer wall the lower edge of which abuts said bottom surface, a portion of said side wall having apertures open to said bottom surface and a portion of said side wall adjacent said fuel inlet being imperforate whereby said fuel inlet is shielded from said combustion chamber thus preventing the formation of carbon deposits producing substantially afelioao' in saidzinlet; said fuelbeing@introduced'itofsaid combustionv chamber: a relatively thine nlm through said apertures and an-v air inlet tothe space between said inner' and.outerwalls.

4; A burner for liquid fuelcomprising an open topreceptacle having an innerfbottom surface, imperforateA side vand-'end1walls',. an :inwardly extending lange on said side and .endwalls spaced above said bottom'. surface, a fuel inlet in one ofA said end iwalls .and imeans to supply liquid fuel thereto,` a plate spacedabovefthe upperedges of said walls, a central opening in said plate, and end flanges depending from said plate adjacent said-,opening forming sideand end wallsdeiining` a combustion chambers saidiflanges extending. downwardly in spaced relation to said side and end'` wallsand-iinto-intimate Contact with the inner bottom surface of said receptacle and with the. inner edge of said inwardly `extending flange, the space below'` said flange forming a fuel vaporizingchamber, relatively narrow vertical slots in said side flanges extending from the bottom thereof to points adjacent the lower surface of saidplate,y saidv endrilanges being imperforateand one said fiange serving to yshield said fuel inlet from said` combustion chamber thus preventing the formationof carbon deposits insaid inlet, said liquid fuel .upon .owng from said inlet to said Vaporizing chamber being vaporized .therein and the fuel'vapor being introduced tosaid combustionY chamber through the lower portions of-said slots.

5. A- burner for liquid fuel comprising an open top'receptacle having an inner bottom surface,v

imperforate side and end walls, an inwardly extending fiange on saidside and end walls spaced above said bottom surface, a fuel inlet in oneof said end walls and means to'supply liquid fuel` thereto, a plate spaced above the upper edgesof saidjwalls, a central opening in said plate, side and end flanges depending from said plate adja.

cent said opening forming side and end walls defining acombustion chamber, saidflangesA extending downwardly in spaced relation toisaid side and end Walls and into intimate Contact with the inner bottom surface of said receptacle and with the inner edge of said inwardly exinlet, said liquid fuel upon flowing from said :inlet to said vaporizing chamberbeing vapo-rized therein and the fuel vapor being introducedfto said:

combustion chamberthrough said apertures.

6. A burner for liquid fuel/comprising anopen top receptacle having an imperforate innerbettom surface and an outer wall, an inwardly ex.

tending flange on said outer wall spacedabove said bottom surface, aV fuel inlet in said outer Wall and means to supply liquid fuelthereto, a

plate spaced above the upper edge of said wall, a central opening in said plate, a nange depending from saidplate adjacent said opens, ing, said'angaex-tending ldownwardly in spaced relation tosaid wall and into intimatecontacty with the inner-bottoml surface of said receptacle and defining, a combustion chamber, theoutersuraCe-Of saidfdepending flange being in intimate contact with the inner edge of said inwardly extending ange, the spacel below saidiflange forming a fuel vaporizingchamber, relativelyy narrow vertical slots insaid flange extending from the bottomithereofto a point adjaeentthelower surface of said D 1ate,a portion. of'said flange being-imperforate and located adjacent said'fuelfinlet whereby said fuel inlet is shieldedffrom said combustionv chamber thus `preventing the formation` ofcarbon depositsin said inlet, said liquid fuel-upon flowing from said inlet to said vaporizing chamber being vaporizedthereinY and the--fuel vapor -be ing introduced to saidcombustion chamber through thelower portions `of said 1 slots.`

7. A- burner for liquidA fuel comprising an l open top receptacle having an-imperforate inner bottom surface and anouterwall, aninwardly extending ange on said outenwall spaced'above said bottom surface, a fuel inlet in said outer wall and means to supply liquid-fuel'theretd afplate spaced above theupper edge ofsaid wall, a central openingin saidV plate, a lian-ge depending. from said plate adjacent said-opening, said flange extending'A downwardlyv in spacedl relation to said wall1and-into-intimate contact with the inner bottom surface of-said-receptacle and' defining a combustion chamber, theouter surface of said depending-.ange being-'in intimate contact with the inner edge of said inwardly- 'extending -flange, the space below. said flange `forming a fuelvaporizi-ng chamber,4 apertures'in-said` ange below said' inwardlyextending flange, a portion of said downwardly extending-flange being imperforate and' located adjacent said fuel inlet whereby said'fuel1inletisshielded-fronr said combustion chamber thus preventing the formationof carbon depositsiinsaid: inlet, said liquid fuel upon flowing vfrom-said inlet to saidl vaporizing chamber-beingv yaporized-`v therein andthe fuelvapor being.- introduced 'to said combustion chamber` through said Y apertures.-

ROBERTS.

References, Cited'in the, flleof this patent UNITED STATESPATENTS Number

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