US2647567A - Oil burner - Google Patents

Description

E. F. CIGLIA OIL BURNER Aug. 4, 1953 Filed July 30. 1951 IN VENTOR ATTORNEYS Patented Aug. 4,1953

UNITED STATES PATENT OFFICE OIL BURNER Ernest F. Ciglia, Mount Vernon, N. Y.

Application July 30, 1951, Serial No. 239,235

17 Claims.

, 1 This invention relates to an oil burner and more particularly to a type of oil burner which is capable of handling very low grade fuels. In

the usual practice, with respect to pot-type oil burners, liquid oil is conducted directly to the burner pot and vaporized in the pot. These burners are objectionable in that at the point of entry of the oil into the pot objectionable and harmful amounts of carbon accumulate. This invention overcomes these difficulties.

This application is a continuation-in-part ofv application, Serial No. 138,312, filed January 13, 1950, for Oil Burner, and now abandoned.

While there have previously been offered pottype burners in which previous vaporization of the fuel is obtained, they have been expensive,

noisy and incapable of handling low grade fuels. Further, as far as is known, these previous vaporizing pot-type burners have introduced fuel at a single point only and have not widely distributed the fuel as in the present invention.

It is, accordingly, one object of this invention to provide a pot-type oil burner in which the oil is previously vaporized or gasified and then fed to the burning section so that the deposition of carbon is eliminated.

It is another object of this invention to pro-" vide such a pot-type burner in which the fuel in its vaporized or gasified state is distributed to the burning section through a plurality of points, widely distributed. It is a primary object of this invention provide a pot-type oil burner of the type described which will handleextremely low grade fuels even those resulting from catalytic cracking of petroleum and commonlyreferred to in the trade as cat oil. v

It is a feature of this invention that complete combustion is obtained even of the very low grade fuels, thus eliminating carbon deposits and providing a highly efiicient smokeless flame. These and other objects and advantages of this invention will be apparent from the annexed specification, in which:

Figure 1 is a plan view partly in section and with parts broken away for clarity of illustra- Referring now more particularly to the drawing, the invention is shown as comprising three primary sections, a fan and fuel supply section H), a vaporizing section I l, and a burning section [2. The fan section is provided with a channel shaped base member l3 upon which is mounted a bracket [4 which carries the metering and thermostatic elements hereinafter described.

An electromotor I5 is provided having its flanges 16 bolted directly to the side of a fan casing or housing I1. The electromotor drives a shaft l 8 which shaft lBcarries a hub [9 having spokes 20 to which are afiixed the blades 2| of a fan.

The shaft l8 also continues beyond the outer wall of the fan and carries a small pulley 22 on the end thereof as shown in Figure 3. The housing I! is also provided with a bracket 23 in which is journalled a shaft 24 which mounts a large pulley 25. Shaft 24 is also journalled in two outstanding bearings 26, 21 and is pro vided intermediate these bearings with worm 28.

The housing ll is provided with a pair of circular openings 29 and 39 in extensions 3| and 32, respectively. The opening 29 is provided with a bearing carrier 33 which is provided with a reduced recess 34 in which is seated a ball bearing 35. Bracket 36 is aflixed to the floor 31 of the housing and carries a bearing 38. A shaft 39 is journalled in the bearings 38 and 35 and extends outward beyond the bearing carrier 33. The outer end of the shaft 39 is provided with a thrust bearing 40 and a worm gear 4| engaging the worm 28, as clearly shown in Figure 2. A tube 42 is mounted in the opening 30, as shown in Figure 2, and has a flange 43 which is secured to a similar flange 44 formed upon the wall 45 of the burner. A tube 50 is provided within tube 42 and carries a pair of spiders 46 and 4! connecting the tube 50 for unitary rotation with the shaft 39. The spiders comprise hubs on shaft 39 and radial legs engaging the inside of tube 50 at spaced points. The tube 50 may, if desired, be provided with a plurality of openings or holes 5|, as indicated. It is preferred that tube 50 be imperforate and it iscontemplated that in commercial production the tube will be without the perforations 5|. A perforated tube is shown in the drawings to -i1lustrate.how such a construction would appear.

The principle of the present invention may be exemplified with an imperforate tube since the inner surface thereof can conveniently support a thin film of fuel oil in heat conducting relation to the tube for purpose of vaporization. By omitting the perforations considerable saving in the cost of production is accomplished and the danger of depositing liquid oil on the bottom portion of hot tube 42 is obviated to a large extent, particularly in the event of failure of the mechanism for driving tube 58 in rotation. As shown in Figures 1 and 3, the tube 50 is spaced from the inner wall of the tube 42, leaving a clearance for a purpose hereinafter described.

The burner comprises a pct 55 having the side wall t and the bottom wall 56. The side wall 45 is extended at 5'! and upon this extension is formed the flange 44 shown in Figure l. A pair of lugs 58 and 59 may be formed upon the bottom wall 56 and are provided with studs 5t and BI, and lock nuts 62 and 63, for the purpose of adjusting the height of the pot. A circular plate 64 is provided within the pot, spaced from the bottom 55, as shown in Figure 4. A cylinder 55 is provided, disposed eccentrically of the wall 65, and defining a crescent-shaped space I50 as clearly shown in Figures 1 and 4, and having its upper portion apertured by a plurality of holes 66 extending entirely about the upper section of the cylinder, as shown in Figures 4 and 5. Asbestos insulation $1 is provided in the form of a ring about the cylinder 65 and retaining ring 68 is provided to hold the asbestos in flrm contact with the cylinder 65. The insulation does not extend to the bottom of oylinder 65 but terminates above the lower end thereof. Resting upon the plate 64 and centrally thereof, there is provided a cylindrical body 'of ceramic material l3, which body it has subturned over flange 32, a depending flange 83 and an inwardly extending flange 84. A ceramic ring 85 is provided having an opening 85 therein and seated upon the flange 84. The opening 86 is coaxial with the ceramic body 73, as shown in Figure 4.

Mounted upon the bracket It is a fuel reservoir 90 to which oil is fed through an inlet 9| and from which oil is fed through an outlet 92. The outlet 92 is in communication with a tube 93, which tube 93 has an end 92 bent to extend into the opening of the tube EU, as shown in Figure 1. The end 94 of tube 93 extends inwardly and downwardly in the end of tube 50 with its open end closely adjacent the inner surface of tube 5i) somewhat below the center thereof.

lower arm lot of the bell crank is bifurcated to embrace shaft m4 between. collars I02 and I03 carried by the shaft Hi l.

Shaft I54 extends downwardly into the reservoir 90 and. has its lower end slotted as at I05 where it enters upstanding cylinder Hi6 forming a portion of the outlet 92. Solenoid 89 may be energized through the conductors I07. Conductors WT lead to an insulated connecting block I58, and other conductors I09 are provided adapted to lead to a ing member band til.

thermostat suitably placed so as to regulate the flow of oil to the burner, and thence to a source of electric power.

It will be apparent that if the solenoid is energized, pivoted armature 855a will be drawn into contact with the core III] of the solenoid and compress spring 99 while moving the shaft 98 to the right, as shown in Figure 6, pivoting the bell crank 96 raisingthe shaft I04 at that point to its upper limit established by the top of casing 81 and allowing oil to flow into the outlet 92 through the slots I05. De-energizing of the solenoid will permit the spring 99 to pivot the armature 39a to the left and release the shaft 34 to gravity to shut off the flow of oil to the burner.

The reservoir is also provided with an overflow mechanism. This overflow mechanism comprises upstanding cylinder I20 in which is provided a float I2I having an upwardly extend- I22 carried thereby. A link I23 is pivotally connected to the top of the upstanding member I22 and has its other end fixedly connected as at I24 to a dogging mechanism I25. A link I25 is pivotally mounted within the reservoir 90 and intermediate its ends pivotally carries a shaft I21, the lower end of which carries a plug I28 adapted to fit within the cylinder I29 forming a part of the inlet and in one position closes the inlet and in another position opens the inlet. The link I26 has one end extending through a slot outwardly of the reservoir 20, as shown at I30. A compression spring I3I has one end attached to the link I26 intermediate its ends and the spring has its ther end attached to the dogging mechanism I25. The dogging mechanism I25 is in the form of a bell crank having an arm I32 extending outward through a slot in the reservoir 90 as shown.

Upon the rising of the float within the cylinder I25, the link I23 correspondingly pivots the dogging mechanism I25 against the force of the spring I3I, thus releasing the dog I33 from engagement with the extension I34 on the link I26 and permitting the link I26 to pivot downwardly and thus plug the member I29. After the overflow mechanism has thus once been tripped, it is necessary to reset the same by hand, and for this reason the extensions Ito and I32 extend outwardly beyond the boundaries of the reservoir 98. The. float mechanism thus limits the head of liquid acting to force fuel through slot so that fuel will not be delivered to tube 50' at greater than a predetermined rate. Of course, other means maybe employed to control the rate of fuel delivery to tube 55.

The innermost end of the tube 553 and the shaft 39 is provided with a spider I4l similar to the spiders it and 4?, as shown in Figures 1 and 2.

Referring now particularly to Figures 4 and 5, a spirally coiled resistance-type heating element 69 is arranged below plate 54 and held in heat conducting contact therewith by any suitable means. The resistance element ti; may be connected by conductors 70 to a suitable source of electric current and appropriate control means. As also shown in Figures 4- and 5, the insulating material t1 does not extend all the way to the bottom of cylinder 65 but terminates short thereof. The cylinder E5 is provided with additional openings II adjacent the bottom edge thereof and below the lowermost edge of the insulating The openings H are at substantially the same level as the upper surface of plate 84.

relative to the speed of the motor 15. specific embodiment illustrated the motor i op- The flange and is provided with an upper surface sloping downwardly, as shown, to a level adjacent the bottom portion of the openings H. The flange portions |4| are shown integral with the pot 55 and integral with bottom 56. Clearly the construction may be readily modified to provide a pot having a terminalflange at its lowermost edge providing the upper portion of the flange I41 and the plate 64 coul'dextend entirely across the bottom thereof with arelatively heavy peripheral clamping ring below the outer margin of plate 64 to hold the assembly in the desired n relationship. In such construction the bottom 56 would be omitted or could be integral with the clamping ring suggested.

When the burner assembly'herein described is installed in a furnace'or the like the burner pot and a portion of the outer tube 42 will extend into the furnace and be exposed to the heat within the .fire box'therein. Such heat will raise the tem- "temperature attained by tube 42 will be quite high, of the same order as that existing in the fire box of the furnace and the hot tube 42 performs an important function in the operation of Q the present oil burner, as will be described later.

As'clearly shown in the drawings the drive effecting rotation of shaft 39 and tube 56 is such that the speed of rotation of the tube is very small In the 'eratesat about 1725 R. P. M. whereas the drive mechanism from thereto the shaft 39 effects a speed reduction of about 30 to 1. Thus it will be seen that tube 50 rotates at somewhat less than 20 revolutions per minute (preferably in a clockwise direction as viewed in Fig. 3). It is contemplated that the speed of rotation of tube 50 be sufficiently high to receive liquid fuel from tube 94' and spread the same in a thin film over "the inner surface of the tube.

The spreading of the oil film longitudinally of the tube is assisted by the blast of air produced by the fan previously described. It is further necessary that the speed of rotation of tube 50 be sufficiently low so that no liquid fuel will be thrown therefrom by centrifugal force to the hot inner surface of tube 42, particularly if tube 50 is perforated. In the embodiment illustrated it was found that the speed of rotation should not exceed about 20 R. P. M. but it will be apparent that a different maximum speed may result if a tube of larger or lesser diameter is employed. The actual speed of rotation for which the burner is constructed must be determined by the dimensions of the ferred to calls for operation of the burner, the

fuel feed mechanism described in connection with Figure 6 will operate in the manner described to start rotation of the fan and tube 50 and to commence feeding liquid fuel through the discharge end 54 of tube 93 into the tube 50. At

the same time suitable control mechanism (not :shown) energizes the heating coil 69 below plate 54. Since the entire burner apparatus is cold at this time the liquid fuel will not be vaporized "but will migrate along tube 50 and some liquid fuel will eventually drop to'the bottom of the portion 5'! of the pot 55 and thence to the upper surface of the flange I41. That liquid fuel will then be fed by gravity through the openings H in cylinder 65 onto plate 64 which is being heated by resistance element 69. As soon as theplate 64 has acquired a temperature sufficient to vaporize the liquid fuel thereon additional control means cause energization of an incandescent ignition coil I 42 (Fig. 1) within the cylinder 65 and will cause ignition of the fuel vapors therein. At this stage in the operation automatic means may effect an opening of the circuit leading to heater 69 since combustion of vaporized fuel and airin the burner will supply sufficient heat to continue the operation. During the preheating period and the initial combustion period some heat will be transferred to the flange l4! but since that flange is of such large mass it can absorb a relatively large quantity of heat without rising to a very high temperature and a large part of the heat absorbed thereby will be conducted to the outer wall of pct 55 and dissipated therefrom by radiation. It is important that the temperature of flange l4! be maintained at a relatively low value during the startingcycle to prevent carbonization of the liquid fuel thereon and/or pre-ignition of fuel in the space between cylinder 65 and pot 55.

As the apparatus becomes warmer the tube 42 will become heated and heat radiating therefrom onto tube 50 will heat the latter to a sufficiently high temperature to directly vaporize all of the liquid fuel existing as a film, as previously described. It is important that the temperature of all portions of the tube 50 be maintained at a value less than that at which cracking or carbonization of the fuel oil would occur. That temperature is of the general order of 500 F. The air passing along the outer surface of tube 50, between that tube and tube 42, is effective to cool tube 50 and prevent its temperature from rising above the point at which carbonization of liquid fuel would take place. The sectional area of the passageway between tubes 42 and 50 will depend upon the material of those tubes, their diameters, the operating temperature within the fire box of the furnace and other forseeable factors al1 of Which can be determined in designing the apparatus. The fan must, of course, furnish a sufficient quantity of air to provide oxygen for use of the fuel fed to the device at the previously mentioned predetermined rate. When the apparatus reaches the point where all of the liquid fuel in tube 50 i being vaporized therein the blast of air moving through the apparatus will entrain all those fuel vapors and deliver a fuel and air mixture into the space I50 between cylinder 65 and pct 55. That fuel and air mixture enters the openings 66 where it is exposed to the heat therein and itself becomes ignited to cause continuou operation of the apparatus. The ceramic body 13 becomes incandescent and insures ignition of all fuel therein and insures maintenance of a high temperature within the cylinder 65, sufiiciently high to oxidize any free carbon that may exist. The insulating material 6'! acts to maintain the cylinder 65 at a sufiiciently high temperature to insure that no vaporized fuel will condense thereon or form a deposit of free carbon thereon.

The vaporized fuel and air mixture entering the space [50 outside the cylinder 65 is at a relatively low temperature compared to the temperature within the burner pot and acts to maintain I the upper portion of cylinder 65, adjacent the openings 56 andthe pot '55, at a sufficiently-low temperature to prevent pro-ignition of the fuel in the space outside cylinder E5. The name produced by theapparatus is directed outwardly through opening 8'6 in ceramic 'ring 85 and a peripheral zone immediately below the ring-85 and adjacent the openings 65 contains fresh fuel and air entering the cylinder which mixture has not yet started to burn. Thus there is no danger of backfire through the openings 66.

'Ehe'-escape-'-ofheat from --the cylinder 65 inthe lower portion thereof by either radiation or con- --duction is minimized bythe asbestos insulation 61. -While the-tube 58 is shown as horizontal, it

need not necessarily .be-so arranged, it could slope downwardly toward the pct 55 or might conceivably even be arranged vertically.

So complete is the combustion obtained in the above described burner, that even "the lowest I grade catalytic cracking oils can be burned with a smokeless, non-carbon-forming flame.

7 -While there has been described what at present is considered a preferred embodiment of the present invention, it will be appreciated by those skilled in the art that variouschanges and modifications can be made therein without departingfrorn the-essence of the invention and it is intended to cover herein al1 such changes and modifications as comewith-in'the true spirit and scope of the appended'claims.

1. "Ap'ot-type oi-1 burner comprising, a burner -pot having an outer wall, a cylinder disposed eccentric-ally-and vertically within-said pot to --de-- If;

-finea *crescerit-shaped "space ther'ebetween, the inside-of said-cylinder comprising a combustion chamber, means-closing the top .andwbott'om iof :said space, ucircumferentiallly .lspaced apertures through the upperiportion of said cyl inder to :ad-

' mit fuelito:saidflcembustion chamber, a fuel yaponizin'g tubamieans defining a passageway from -isaizdtube into I the prescient-shaped space between -:said' outer waill and: cylinder tangentially :of said icylinder eandadjacentnne end :of said: space, said throughaxsaidtube andzpassageway .into said mouiand heat insulating:means around said 03 1- iiindcr ibelowxsaid apertures to substantially prewent mediation .into said uap'orizingftube.

72.1;111 :oil i'burner, L81 burner .pot' acomprising :argenerally rcylindrical outer 'walLa slinllowimetal cylinderzwithin and spaced :Ercm saidiouter Wall, @mean-siclesing'the of the .space' betv een said cylinder and outer wall, a heat.- conductive plate :closing .the bottom end .of said cylinder, means doradmitting vaporized fuel and air to .the :space ibetweensaid-outer wall and cylinder, circumferentiallyspaced apertures through the .upper ,por tion -of .saidscylinder providing .for admission ,of *ful and air to the insideof said cylinder from ,said .space, means for admitting .liquidstarting afuel into saidcylinder-on said heat conductive iplate, .and .auxiliary heating -means .below P's-aid ..plate lto :initiallyheat :the same and ivaporize the istarting=fuel thereon.

3; Aburner pot as definediin .claim .2 wherein saidimeans-lfor admitting liquid starting fuel.,to said cylinder comprises, openings .through- :said cylinder adjacent the bottom ithereof, .a bottom wall -.for thespace between. said I outer wall -..and ,ccylinder said bottom wall :slppin-g inwa1d1y and :8 downwardly to=the level of said openings, said bottom wall being of-heat conductive material and being of large mass, and meansfor dissipating heat absorbed by said bottom wall.

l. A liquid fuel vaporizing apparatus comprising, a stationary outer cylindrical tube a vaporizing tube rotatably mounted coaxially within said outer tube, the outer surface of said vaporizing tube'being spaced radially inwardly of the inner surface of said outer tube, means for blowingairthrough said-vaporizing tube and-the space between said tubes from one end thereof, means for positively depositing a filmof liquid fue1 on the inner surface of said vaporizing tube on a localized portion thereof adjacent said one end andat a predeterminedrate, means independent of air flow for rotating said vaporizing tube at a controlled speed sufiicient'to cause said liquid fuel film to spread over a substantial portion of the inner surface thereof as a relatively thin :filrn but at aspeed not exceeding about twenty revolutions per minute, and means for heating said outer tube whereby to heat said vaporizing tube by radiation to vaporize the fuel film thereon.

.5.In an oil burner, a burner pot comprising, an outer cylindrical wall having a closed bottom,

. an inner hollow metallic cylindrical wall supported by said bottom and eccentrically positioned within said outer wall, means closing the upper end of the annular space between said cylinder I and wall, means for admitting vaporized fuel and air to the said closed space, circumferenti-ally spaced apertures through the upper portion of said cylinder to provide for admission of fuel and air to said cylinderfrom said space, a layer of heat insulating-material around said cylinder below said apertures, and an annular flange of ceramic material extending inwardly from the upper edgeof said cylinder.

6. A burner pot asdefined in claim 5 including aperforate body of ceramic material centrally positioned in said cylinder on said bottom.

'7. In a method of vaporizing liquid fuel, the steps of depositing a film of liquid fuel on a heat conductive surface at a predetermined rate, moving said film over said surface at a predetermined and controlled speed so as to spread said fuel film over asubstantial portion of said surface, fiowing a current of air over said surface and film, supplying sufficient heat to said surface to vaporize said fuel into said current of air, and limiting the heat supplied to said surface so that the temperature of unvaporized fuel does notexceed about 500 F.

.8. In a method of vaporizing liquid fuel, the steps of depositing a film of liquid fuel on. one face of a heat conductive surfaceiat a predetermined rate, moving said film over a substantial portion of said surface at apredetermined and controlled speed to spread said liquid fuel over said one face as a thin film, heating said surface by radiation sufficiently to vaporize said film, and blowing a stream of air over both sides of said surface to carry awayvaporized fuel and to maintain said-surface ata sufficiently low temperature to prevent carbonizing said fuel.

9. A fuel vaporizing device for use with a pot burner comprising: a fuel vaporizing tube, means spaced from said tube and defining a discharge passageway leading from said tube, said tube being arranged to receive heat by radiation from said means, means-for positively depositing liquid fuel on a-surface of said tube to form a liquid film thereon-adjacent the end thereof remote from said discharge passageway andat a predetermined rate, a fan arranged to blow air through said tube and passageway, and means independent of air flow for rotating said tube about its axis at a predetermined controlled rate great enough to spread the film of liquid fuel over said surface but not great enough to throw said liquid fuel therefrom by centrifugal force.

10. A device as defined in claim 9 wherein said passageway is defined by a fixed tube coaxial with and surrounding said fuel vaporizing tube but radially spaced therefrom, and means for heating said fixed tube, said fan being arranged to also blow air along the space between said tubes.

11. A device as defined in claim 9 wherein said fuel vaporizing tube is arranged with its axis substantially horizontal and wherein said fuel depositing means-is arranged to deposit liquid fuel on the inner surface of said tube.

12. A pot-type oil burner comprising: a burner pot having an outer wall, a cylinder disposed eccentrically and vertically within said pot to define a generally crescent-shaped space therebetween, circumferentially spaced apertures through the upper portion of said cylinder, means defining a passageway for a vaporized fuel mixture into said crescent-shaped space generally tangentially of said cylinder and adjacent one end of said space, and means closing the top and bottom of said crescent-shaped space.

13. An oil burner as defined in claim 12 including a cylindrical body of ceramic material disposed substantially concentrically within said cylinder.

14. An oil burner as defined in claim 13 wherein said cylindrical body is of tubular form and provided with openings therethrough at a plurality of spaced points about its periphery.

15. An oil burner as defined in claim 12 including a layer of heat insulating material around the outside of said cylinder below the said apertures.

16. An oil burner as defined in claim 12 wherein said space between said outer wall and cylinder is closed at the top, a body of ceramic material disposed substantially centrally within said cyl- 10 inder, and a ring of ceramic material disposed over said cylinder and partially closing the top thereof, there being an opening through said ring substantially centrally of the top of said cylinder.

17. A pot-type oil burner comprising: wall means defining a combustion space, further wall means defining a closed fuel chamber adjacent said combustion space and means defining a fiow path for conducting vaporized fuel from said chamber to said space, vaporizing means for liquid fuel including an open-ended vaporizing tube directed toward said chamber, means spaced from said tube defining an open passageway therefrom to the interior of said chamber and being in heat conducting contact with the Wall means defining said chamber, and radiation obstructing means interposed between the wall of said combustion space and the interior of said passageway to prevent direct radiation of heat from said combustion space into said vaporizing tube.

ERNEST F. CIGLIA.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 404,428 Paine June 4, 1889 548,647 Mack Oct. 29, 1895 1,453,495 Doble May 1, 1923 1,646,043 Stevens Oct. 18, 1927 1,658,462 Peterson Feb. 7, 1928 1,670,274 Oglivy May 15, 1928 1,677,447 Higgins et al July 17, 1928 1,725,218 Skaer Aug. 20, 1929 1,835,297 Grant Dec. 8, 1931 1,896,247 Rudorf Feb. 7, 1933 1,903,364 Grant Apr. 4, 1933 2,119,922 Lutz June 7, 1938 2,309,319 Johnston Jan. 26, 1943 2,344,439 Lloyd Mar. 14, 19 4 2,408,865 Mackaye Oct. 8, 1946 2,416,932 Litzenberg Mar. 4, 1947 2,456,170 Bennett Dec. 14, 1948

Images