US2603281A - Vaporizing fokced draft oil buhner - Google Patents

Description

July 15, 1952 w. H. FRANKLAND 2,603,281

VAPORIZING FORCED DRAFT 011. BURNER Filed Maya, 1949 INVENTOR. W157. Fran/(land A Ziarrzeys Patented July 15, 1 952 UNITED srArss VAPORIZING FGRCED DRAFT cit semis- William Howard Frankla'nd, time, Fla. Apeueauiin Mai-$1949; serial Nd.- 90,822

The present invention in general relates to oil burners of the type generally known as pot type burners, and more particularly to oil burners of the" forced draft rare-vaporizing variety wherein the fuel oil is vaporized into g'a'seous form and mixed with a quantity of air immediately. upon introduction into the oil burner to form a highly combustible mixture:

Pot type burners of the type heretofore in use are designed to effect'conversion ofthe liquid fueloil supplied to the oil burner to support combus tion therein into a" combustible gaseous mixture on introduction of the fuel, oil into the burner,- the'pro'cess of being referred to in'the art as prevaporization. These burners, in general com prise a metal pot or cylindrical recept'aole, usually of sheet metal, with a top having an ,openingfor the discharge of flames, and" often having perforationsin its sides, Oil is delivered to the bot tom of the pot; and air under some pressure is delivered within a surrounding casing to enter the pot; as through the perforations in the side walls. The flame being started by ignition of liquid fuel oil uponthe bvOttom; or other combustible material within the pot-, fuel oil gas is generated by the heat radiated from the flame within the pot; and in; part by heat conducted. through the walls of; the pot to the liquid oil upon the bottom; and'thus the combustion continues.- Such a burner is a very simple type of inexhensive construction, and has come into gener'al use for suchreas'ons. It is, however, inefiie cie'nt'in" that theioil is not thoroughly gasified, and the flame generated is a' yellow flame, indicating imperfect combustion and, therefore, loss ofefiiciency; The imperfect combustion-c'h'arac t'eristics in such burners isfurther indicated by deposits of carbon inand about the burners; suchdepositslieinga common characteristic of this type of burner. V Y l Burners have also been constructed to provide this'pre-vapori'zation feature by means of a va-I pori zing chamber or pot into which the fuel-oil inlet to the burner is couiiled, which chamber is constructed of a highly thermo'conductive material disposed in the portion ofthe burner in" which combustion takes: place. Inthis' manrier, the heat'generated on?combustion or the volatile mixture in the urner retains, the material form: ing the wan's'of the-vaporizing chamber at a; sufficiently'" high temperature to vaporize the fuel oil mimediamy upon ts introductioii' into t chamber and erreet conduction of the'fv'aporizedair through "generations; into the combustion chalfifiij-wfiie it 'iSWIiiXediWith sufficient uail: tit'ie's' of ai'r tof c'reatethe cmbustib1e;g as.

\ Ifiitiailighting of the-burner; from-a *(50111 t ciaiiiii (c1. 1584i) 7 start] is'generallyeii eotedby a pilot or similar heat element disposed adjacent the vaporizing chambenedapted to ignite liquid fuel oil overflowing from the chamber onto suitable cups or channels conveying the" liquid fuel oil to a point adjacent the pilot orlother igniting means. A particular problem arises in connection with these prior art vaporizing oil burners, in thatin many of such burners, the flame resulting frc irn burning of the liquid fuel oil or of the vaporized gaseous fuel reaches the various fuel feed cone ducting outlets in the supply system within the Oil u n Q s nadeeo i v0 t. t.a l ;.0 1 3. a o i e m r a about, t ese .e menis,.. nd. a reduction i t e ifiq eh y lot the s st mhsz. restricting i i n an conduc o 1 a into the co bu chamber. 9f urne This, general; isdue to the inapfljtycfthe sy m t w-su pl s fi c ent ua. i eaq al d lng combustion of the n u u'ruerou arg flig t n o t e urn r, t rr uceafiqlean." flamp e time. as oe a e nw h s bstanti ly ,cpm leie ombusi pn ei th fu lzqqmp ems- ,Ma r vnei v or in o llqiirne .heva ee i an to. ow u W enisi edin a h t.verm i e raimcondition, that is, when the burner is re-ig'nited a short time after it has just shut oijpperatififi. t s because oi.th. s,..t n iemt i ih ll ias d; e qnlycpa ti l .ra riz dfee 911.1 9 are quantities of soot and other'carboniz ed during om ustion. t a sneer,9 v he. oil burners n evida erjn u implrp ai is a riz ne m mbe t e yep r v. be cond ted n c aflsepe eie. embi iiee erlwher -unmix w h a r tenros i qe the combustible mixture jI-he air supplid to the cbmbustibn h m in; su h ur e weeds-genera ly ot i p o erauenti ytqefieqt. substantiallycomplete combustion of the fuel oil inf-both liquidand;gaseous states and reduce carbonzdepo'sits onthe elements of the burner toanegli'giblequantity.

Likewise: in; many of the is fed: directly fromith'e' vaporizing; chamber into the combustion chamber oftheburner and irnmediately' Y exposed to the flame; an insu-fiicient timeis" available topermit Tan optimum: mixture of air with; the (vaporized fuel, and the ran e of types offuel oil-which can be used in such burners isthereby'severeiyrestripted; l

It is nuobiect of t e; p ese t i vent on: to. provideija fuel oil; vaporizing burner which may; be employed" in fuel ;oil furnaces now in use to facilitate the generation of gas, and liquid: fuel oiland .toinsure icognplete combustion.

- Another object Of'the' present invention istiij;

oriorert vaporizing oil burners, since the vaporized; or gaseous fuel 3 provision of a fuel oil gas generator suitable for use in a pot type oil burner which may be readily adapted to any such type of burner now in commercial use, or which may be incorpoigated in or supplied with new burners of the pot ype.

Another object of the present invention is the provision of a novel vaporizing oil burner adapted to generate a vaporized fuel oil and air mixture upon introduction of the fuel oil into the burner and conduct this mixture into the combustion chamber of the burner for further mixture with air in an appropirate quantity to insure complete combustion.

Another object of the present invention is the provision of a novel vaporizing oil burner wherein effective forced draft ventilation is provided in the vaporization and combustion sections of the burner to insure complete combustion during burning of either liquid or vaporized fuel substantially without carbonized combustion residue.

Another object of the present invention is the provision of a novel forced draft oil burner in which liquid fuel is vaporized and mixed with quantities of air insufficient to support combustion before introduction into the combustion chamber, and then mixed with additional quantitles of air, characterized by substantially complete combustion of the fuel supplied thereto and high-efliciency operation.

Another object of the present invention is the provision of a novel vaporizingoil burner having a fuel oil vaporizing chamber or highly thermoconductive material and adapted upon initial lighting of liquid fuel oil in the burner to produce a continuous ring of flame surrounding the chamber and rapidly heat the material to oil vaporizing temperature.

Other objects, advantages and capabilities of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawing showing only the preferred embodiment of the invention.

In the drawing:

Figure 1 is a vertical transverse section view of a vaporizing forced draft oil burner embodying the present invention; and

Figure 2 is a horizontal transverse section view taken along the lines 2-2 of Figure 1.

Referring to the drawing, wherein like reference characters designate corresponding parts throughout the several figures, the present invention includes a fuel oil burner, generally indicated at In, adapted to provide a source of heat for a conventional furnace of the hot-water or forced air types. The burner I is provided with a base II forming a substantially circular platform, preferably a casting of highly thermoconductive material, in a horizontal plane'and mounted adjacent the base of a furnace in the lower portion thereof by suitable brackets or other conventional mounting means (not shown) Mounted on the circular base II of the burner is a vertically extending tubular shell forming a housing I2 definingthe combustion chamber of the burner, indicated at I3. The lower periphery of the cylindrical shell I2 is adapted to fit snugly within an upstanding circular ring It provided on the base member I I adjacent the outer periphery thereof and forming'an oil retaining wall. The oil retaining wall I4 serves as a safety wall adapted to meet the requirements of the Underwriters Code, and is of suflicient height to retain a sufflcient quantity of liquid oil fuel 'within the 4 burner to prevent overflow of the oil from the burner should the burner fail to ignite. It is understood that a safety control valve is generally provided with the oil delivery system, of the float valve variety, which trips off before the oil reaches the upper edge of the oil retaining wall should the oil fail to ignite, and prevents further flow of oil into the burner.

Centrally located on the base member I I within the combustion chamber I3 is a vaporizing chamber or pot, generally indicated at I5, adapted to effect vaporization of the liquid fuel oil introduced into the system into a gaseous form and mix the same with air before introduction into the combustion chamber I3. To this end, a raised circular platform I6 is provided on the upper surface of the base member II, with its axis coincident with the axis of the burner base I I. The upper surface of the raised platform I6 may be provided with a series of concentric grooves, indicated at IT, about the upper surface thereof described about the central axis of the raised platform I6.

In the center of the raised platform is is an oil inlet opening is extending through the base member II concentric with the axis thereof. Coupled with the inlet opening I8 is a coaxial threaded aperture I9 extending through a portion of the base member II adapted to receive a threaded coupling 20, for removably coupling a fuel oil conduit 21 extending from a suitable fuel oil supply source (not shown) to the oil inlet opening I8.

A substantially cylindrical cup or hood 22 is provided, having a rim 23 forming the side of the chamber I5 of very slightly larger diameter than that of the raised platform H; on the burner base I I, and is adapted to be slipped loosely over the edges of the raised platform IS. The top 24 of the hood 22 is substantially disk-shaped, and is provided with a central ventilating aperture 25 extending therethrough and disposed directly above the oil inlet hole I8 when the head 22 is in place about the raised platform It. A plurality of ventilating apertures or conduits 26 are also provided in the top 24, spaced in a circular path near the outer edge of the housing 22 about a radius of the surface 24.

An asbestos endless circle wick 21 is fitted snugly about the outer wall of the hood 22 with the'bottom edge of the wick resting upon the burner base II and the top edge of the wick being substantially flush with the top 24 of the vaporizing chamber hood 22. A circular groove 28 of the same diameter as that of the wick 21 may be provided in the upper surface of the burner base II underlying the lower edge of the endless wick 21 for purpose to be later described.

A recess 29 is disposed about the rim 23 of the hood 22 adjacent the upper edge thereof, permitting the wick when disposed in surrounding relation to the hood 22 to be free from contact with the sides of the hood along the upper portion of the wick.

Hot wire ignition means is provided: in the burner base II, comprising a journal fitting 3| extending through the burner base I l and having a tubular, partially threaded aperture extending therethrough adapted to receive and mount a hot wire igniter 32 having a high resistance wire 32' having a loop or coil 33 formed along the wire 32' disposed adjacent the upper edge of the inner circle wick 21 along a portion thereof to effect igniting of fuel oil absorbed by the wick 21 when the coilis energized. The hot wire igniter 32 may be electrically coupled in a'conventional manner across any suitable electric energy source (not shown). 7

Extending upwardly from the top 24 of the hood 22 and mounted thereon is a perforated tubular member 35 having longitudinally spaced series of perforations 36 extending through the walls thereof and axially directed laterally toward the combustion chamber IS. The lowermost group of perforations, generally indicated at 35, arepreferably' arranged on slightly downwardly inclined axes to direct jets of air across the edge of the wick 27 and toward the burner basei I. The upper portion of the tubular mem ber 35 may be provided with an elbow coupling 31 or other suitable means connecting the upper edge of the tubular member 35 with the outlet of a'blower or fan, indicated at 38, of any of the commercially marketed types, such as a small Sirocco fan commonly employed in connection with forced draft burners.

Operation of the subject inventionis substantially as follows: It is assumed, for purposes of this description, that a conventional thermostatically operated burner control valve is employed in conjunction with the burner, of the type having a bi-metallic control strip adapted to be heated by local electrically energized means, and which when heated, bends upward through a predetermined path. During'its upward travel, it progressively actuates a switch in the energizmg circuit of the bloweror fan 38, and simultaneously closes the energizing circuit to the hot Wire lgniter 32. As the bi-metallic strip progresses in its upward movement, it then opens a fuel oil feed control valve in the feed line 2! to permit oil fi'ow'upward through the feed line and coupling fitting 28 and the oil inlet opening l8 onto the raised platform It of the vaporizing chamher [5 The liquid'fuel oil entering through the opening l8 and onto the raised platform I 6, flows laterally between the loose fitting side or rim 23 of the vaporizing chamber hood 22 and the side of the raised platform l6 and along the bottom of the burner base H to the groove 28 underlying the endless circle asbestos wick 27. v

The asbestos wick 27, when contacted by the oil, absorbs the oilrapidly, conducting it to the top of the wick immediately adjacent the loop or coil '33 formed in the energized hot wire lighter 3.2,where the oil is ignited. It will be apparent that the flame resulting from the burning oil will be confined to the upper edge of the endless circle Wick 21 about the area where the wick is spaced from the sides of the hood 22, due to the recess about the edge thereof. A large supply of forced air is, at thesame time, directed downwa'rdly radially outward through the lower series of perforations in the tubular member 35 in the direction of the circle of flame from the burning oil extending about the upper edge of the endless circle wick 27. This supply of forced air is sufficient tosupport substantially complete combustion of the fuel oil so that the oil burns with a clean flamesubstantially free of carbonized residue. This likewise serves the purpose of directing the flame outwardly and downwardly from the upper edge of the endless circle wick '2"! to cause very rapid heating of the burner base ll to a sufficient temperature to cause immediate vaporization of the liquidfuel oil a's'it enters the vaporizing chamber l5 through the oil inlet grooves" "provided in the uppersurface of the raised platform It increase the surface of the raised platform which the fuel oil is brought into contact with to facilitate rapid vaporization of the oil. I I

Simultaneously with the conversion of the liquid fuel oil into agaseous state dueto the high temperature of the raised platform l6, oxygen is mixed in the chamber [5 with the vaporized fuel oil, air being forced by means of the fan 33 downwardlythrough the tubular member 35 and the central 'openin g'25 in the top 24 of the hood 22 to eifect pre-mixing of the vaporized fuel oil with air in an insuflicient quantity to support combustion. The mixture of vaporized fuel oil and airis conducted through the series of openings 26 in the top of thev'aporizing chamber [5 and into the combustion chamber l3 where the same is ignited by the flame occurring on combustion of the liquid fuel oil absorbed by the endless circlewick .27. The

opening is and contacts'the upper surfaceyof the raised platform 16. The concentric cire'ula'r mixed air and vaporized fuel oil is forced outward through openings 26 and into the combustion chamber by the pressure generated in the vaporizing and mixing chamber It by the forced air directed downwardly through the tubular member 35and aperture 25. Combustion'with in the chamber l3 will be readily sustained by the continuous supply of mixed air and vaporized fuel oilforced through the openings 26, after the liquid fuel oil'absorbed by the asbestos Wick 27 has been exhausted "through combustion.

While but one particular embodiment of the invention has been particularlyshown and described, itis distinctlyunderstood "that the in-' vention is not limited thereto but that various modifications may be made without departing from the spirit and scope of the invention, and it is desired, therefore, that only suchlimitations shall be placed thereon as are imposed by the prior art and are set forth in the appended claims.

What is claimed is:

V 1. Ina burner, the combination of a burner base plate and a liquid fuel delivery passage having an outlet in said base plate, enclosure means defining with said base plate a gas generating chamber disposed in surrounding relation tosaid outlet, second enclosure means disposed in surrounding relation to the first enclosure means defining an upwardly opening combustion chamber, forced draft generating means having an elongated conduit extending through said second enclosure means and coupled to said first ejne closure means for delivering air downwardly through a restricted orifice in said first enclosure means disposed oppositely of said fuel outlet to form a downwardly directed jet. directed toward said outlet for mixing air with the gas generated therein, a plurality of apertures formed in said first enclosure means and spaced outwardly from said elongated conduit to deliver the mixture of gas and air from said gas generating chamber in upwardly directed jets, said elongated conduit having a vertically arranged series of perforations delivering additional quantities of airintoaip andg'aseous fuel to generate a combustible mixture.

, 2. In a burner, the combination of a burner base plate of highly thermoconductive' material,

'a liquid fuel V delivery assa e ,coupled thereto having an outlet" orifice dispbs'edin said base 7 plate, hood means disposed in surrounding relation to said orifice forming with said base plate a gas generating enclosure, means extending from said burner base forming a combustion chamber surrounding said gas generating enclosure, forced draft means for delivering air downwardly through a restricted orifice in said hood means into said gas generating enclosure fo mixture with the gas generated therein, an annular seriesof apertures formed in the top of said hood means and spaced outwardly from said forced draft means to deliver the mixture'of gas and air from said gas generating enclosure to said combustion chamber in upwardly directed jets, and said forced draft means having apertures for delivering air laterally in radially directed jets into said combustion chamber intercepting said upwardly directing jets in suflicient quantity to form a combustible mixture, an endless fuel absorbent wick disposed in surrounding relation to said hood means, means providing passage for liquid fuel'frcm said exit orificeto said wick, and igniter means disposed adjacent said wick to ignite liquid fuel oil absorbed thereby, whereby a ring of ignited fuel oil is provided on initial lighting of said burner entirely surrounding said gas generating enclosure, at least some of said forced draft jets being arranged in outwardly and downwardly inclined directions across said wick and toward said burner base plate to facilitate heating of said burner base plate to a fuel vaporizing temperature.

3. In a burner, the combination of a burner base plate of highly thermoconductive material capable of supporting a film of fuel, a liquid fuel delivery passage coupled thereto having an outlet orifice disposed in said base plate, hood means disposed in surrounding relation to said orifice forming a gas generating enclosure, means extending from said burner base forming a combustion chamber surrounding said gas generating enclosure, forced draft means including a tubular elongated conduit for delivering air downwardly through a restricted orifice in said hood means into said gas generating enclosure for mixture with the gas generated therein, an annular series of apertures formed in the top of said hood means spaced outwardly from said elongatedconduit to deliver the mixture of gas and air from said gas generating chamber to said gas chamber in upwardly directed jets, said elongated conduit having a vertically arranged series of apertures for delivering air in radially directed jets into said combustion chamber intercepting said upwardly directing jets in sufficient quantity to form a combustible mixture, an endless fuel absorbent wick disposed in surrounding relation to said hood means, means providing passage for liquid fuel from said exit orifice to said wick, and igniter means disposed adjacent said wick to ignite liquid fuel oil absorbed thereby, whereby a ring of ignited fuel oil is provided on initial lighting of said burner entirely surrounding said gas generating enclosure, the lowermost of said series of apertures in said elonated conduit being arranged along radially and outwardly inclined axes to provide jets of air across said wick and toward said burner base plate to facilitate heating of said burner base plate to a fuel vaporizing temperature.

4. In a burner, the combination of a highly thermoconductive burner base plate capable of supporting a film of fuel, a liquid fuel delivery passage coupled thereto having an outlet orifice disposed in, said base plate, cylindrical hood means of highly thermoconductive' material'disposed in surrounding concentric relation to said orifice forming a gas generating enclosure, means extending from said burner base forming a combustion chamber surrounding said gas generating enclosure, forced draft means including a tubular elongated conduit for delivering air downwardly through a restricted orifice in said hood means axially aligned and disposed oppositely relative to said fuel outlet to form a downwardly directed jet intercepting said fuel outlet for mixture with the gas, an annular series of openings formed in said hood means adjacent and immediately outwardly of said elongated conduit for directing the vaporized gas mixture from said gas generating enclosure to said combustion chamber in the form of upwardly directed jets, said elongated conduit having a vertically arranged series of apertures for delivering air in radially directed jets into said combustion chamber intercepting said upwardly directed jets to form a combustible mixture, an endless fuel absorbent wick disposed in surrounding relation to said hood means, means providing passage for liquid fuel from said exit orifice to said wick, and igniter means disposed adjacent said wick to ignite liquid fuel oil absorbed thereby, whereby a ring of ignited fuel oil is provided on initial lighting of said burner entirely surrounding said gas generating enclosure, the lowermost of said series of apertures in said elongated conduit being arranged along downwardly inclined radial axes to provide radial jets of air extending across said wick and directing the flame thereon toward said burner base plate to facilitate heating of said burner base plate to a fuel vaporizing temperature.

5. In a burner, the combination of a highly thermoconductive burner base plate capable of supporting a film of fuel, a liquid fuel delivery passage coupled thereto having an outlet orifice disposed in said base plate, hood means of highly thermoconductive material disposed in surrounding relation to said orifice forming a gas generating enclosure, means forming a combustion chamber surrounding said gas generating enclosure, forced draft means including a tubular elongated conduit for delivering air downwardly through a restricted orifice in said hood means into said gas generating enclosure for mixture with the gas, a plurality of apertures formed in the top of said hood means and spaced outwardly from said elongated conduit to deliver the mixture of gas and air from said gas generating chamber to said combustion chamber in upwardly directed jets, said elongated conduit having a vertically arranged series of apertures for delivering air in radially directed jets into said combustion chamber intercepting said upwardly directed jets to form a combustible mixture, an endless fuel absorbent wick disposed in surrounding relation to said hood means, means permitting flow of the liquid fuel from said exit orifice to said wick, and igniter means disposed adjacent said wick to ignite liquid fuel oil absorbed thereby, whereby a ring of ignited fuel oil is provided on initial lighting of sad burner entirely surrounding said gas generating enclosure, the lowermost of said series of apertures in said elongated conduit being disposed immediately adjacent the upper extremity of said hood means and arranged to provide radial jets of air directing the flame from the ignited fuel on said wick outwardly and downwardly toward said burner base plate to facilitate heating of said Laurner base plate to a fuel vaporizing temperaure." r

6. In a burner, the combination of a burner base plate of highly thermoconductive material, a cylindrical housing disposed on said base plate forming therewith a gas generating chamber, a liquid fuel delivery passage having a feed outlet formed in said base plate and opening into said cylindrical housing along the axis thereof, tubular means disposed on said base and surrounding said cylindrical housing to define a combustion chamber, a restricted orifice forming an air delivery opening in said cylindrical housing axially aligned and oppositely disposed relative to said fuel outlet, forced draft generating means having an elongated conduit extending through said combustion chamber for delivering a forced draft of air downwardly through said restricted orifice to agitate vaporizing the fuel admitted through said outlet and mix air with gas generated in said chamber, an annular series of apertures formed in the top of said cylindrical housing spaced outwardly from said elongated conduit to deliver the mixture of gas and air from said gas generating chamber to said combustion chamber in upwardly directed jets, said elongated conduit having a vertically arranged series of apertures for delivering air in radially directed jets arranged in horizontal planes perpendicular to said jets of mixed gas and air into said combustion chamber.

7. In a burner, the combination of a burner base plate and a liquid fuel delivery passage having an outlet in said plate, cylindrical enclosure means defining a gas generating chamber disposed in surrounding concentric relation to said outlet, second enclosure means disposed in surrounding relation to the first enclosure means defining a combustion chamber, forced draft generating means having an elongated conduit extending downwardly through said combustion chamber and coupled to a restricted orifice in said cylindrical enclosure means axially aligned with and disposed oppositely of said fuel outlet for delivering air downwardly into said gas gen erating chamber in an axially downwardly directed jet and mixing air with the gas generated therein, an annular series of upwardly directed openings in said cylindrical enclosure means arranged adjacent and concentrically outwardly of said elongated conduit to deliver mixed gaseous fuel and air from said gas generating chamber to said combustion chamber in the form of upwardly directed jets, said elongated conduit having a vertically arranged series of perforations for delivering additional quantities of air into said combustion chamber in the form of radially directed jets extending in planes perpendicular to the axis of said elongated conduit and intercepting the jets of mixed air and gaseous fuel delivered from said cylindrical enclosure means.

WILLIAM HOWARD FRANKLAND.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 427,946 Adams May 13, 1890 1,232,392 Pilquist July 3, 1917 1,552,899 Walker Sept. 8, 1925 1,668,773 La Branch May 8, 1928 2,129,239 Rook et al. Sept. 6, 1938 2,257,548 Fischer Sept. 30, 1941 2,262,922 Castle et al Nov. 18, 1941 2,480,728 Griewank Aug. 30, 1949

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