US2643916A

US2643916A - Fuel burner

Info

Publication number: US2643916A
Application number: US89418A
Authority: US
Inventors: Gerald A White; Lewis W Williamson
Original assignee: CF Braun and Co
Current assignee: CF Braun and Co
Priority date: 1949-04-25
Filing date: 1949-04-25
Publication date: 1953-06-30
Anticipated expiration: 1970-06-30

Description

June 30, 1953 G. A. WHITE ET AL FUEL BURNER Filed April 25. 1949 rroR/vfrs.

Patented June 30, 1953 Nr orrice- FUEL BURNER Gerald A. White, Los Angeles, and Lewis W. Williamson, Wilmar, Calif., assignors to C. F. Braun & Co., Alhambra, Calif., a corporation of California Application April 25, 1949, Serial No. {89,418

This invention relates to fuel burners and is particularly directed to improved apparatus -for efficient burning of liquid fuel, such as oil.

Present day oil fired heaters suffer from poor fuel utilization, high maintenance cost, and operating difficulties brought about by relatively inefficient oil burners. Consequently, theheater unit itself mustbe made larger and more expensive because of the larger fuel volumes required for heat release from the fuel oil as compared with gaseous fuel.

yThe principal objects of this invention are to provide a novel form of steam-atomizing oil burner of the external mixing type which (a) burns cleanly. with a. minimum of residue, (b) accommodates itself automatically to varying loads within a wide range, (c) provides excellent atomization throughout this range, (d) burns with a confined efficient flame with a short wide pattern, and (e) may be quickly and readily cleaned in the event foreign matter should lodge near the fuel orifice.

More specifically it is an object of this invention to provide a steam-atomizingoil burner incorporating 'a novel form of nozzle having adjacent ring-type orifices for fuel and steam.

A related object is to provide adjacent orifices for steam and fuel oil arranged so that rthe burner tip is kept clean in operation and so that oil drips do not form. Y

Other more detailed objects and advantages will appear hereinafter.

In the drawings:

Figure l is a longitudinal sectional view showing one embodiment of our invention.

Figure 2 is a transverse sectional View taken substantially on the lines 2 2 as shown in Figure l. v

Figure 3 is a transverse sectional View taken substantially on the lines 3 3 as shown in Figure l.

Figure 4 is a perspective view of a burner tip member employed in connection with our invention.

Figure 5 is a perspective View partly broken away showing adeflector elementemployed in connection with our invention.

Figure 6 is a longitudinal sectional detail on an enlarged scale andk partly broken away showing a preferred arrangement for adjacent ring orifices for steam and fuel.

1 Claim. (Cl. 299-141) 2 l Referring to the drawings, a shell Hl is provided with a central bore Ilwhich terminates at a conical face i2 adjacent the outer end I3.

Figure 7 is a sectional detail 'partly broken away showing a modified form of mechanism ring orice during operation. y

A deflector member generally designated I4 is provided with axially extending angularly spaced guide fins l5 which are slidably received within the bore il of the shell it. The deilector memberl is provided with an axial bore It which receives the stem portion Il of the burner tip member generally designated I6. Angularly spaced fluted guides I 9 extend axially on the stem Il and are received in sliding relationship within the axial bore I6 of the deector member It. A flanged head or tip 2t is provided on the outer end of the member l8.- The underside 2| ofthe burner flange 2l! cooperateswith the outersurface 22 of the flared lip 23 formed on the outer end of the member YHl to provide la continuous ring orice 24. The inner surface 25 of the flared lip 23 cooperates with the conical face I2 on the shell i6 to provide a second ring orifice 2B. f

The ring oriiices 23 and il@ are formed as continuous circles and are separated only by the flared lip 23 on the member 14. ing through the axialopening i6 is 'sprayed in a forwardlyv directed cone outward from the orifice 2i. This oil mixes With-aeamissuiug in a forwardly directed cone from the orifice 26.

so that atomization of thev oil occurs exteriorly of the burner assembly between the intersect- 'ing cones of fuel and steam; The relationship of the flared lip 23 with respect to the surfaces 2| and l2 insures that the burner tip is kept clean and so that oil drips do notjform. The steam adjusts the size' of the flame by its impinging action lexterior to the oil spray, and the burner tip is prevented, from overheatingA and fouling. As shown in Figure 6 of thedrawings the steam may emerge from the orifice 26' at about'a .35 angle and the oil may emerge from the orifice 24 at about a 15 angle, so that the contact angle between the oil and steam is 20. This is a preferred arrangement, ybut we have found that angles of to 39, for the oil and 5 to 60 for the steam operate satisfactorily providing the contact angle between the steam and oil is at least 5. Air for combustion is drawn inwardly vthrough the opening .3S and Vpasses around the shell It and axially thereof to supply oxygen for the flame. The velocity of, the

blast of air passing inwardly through theopening -36' affects thepattern of the name: good dis tributionof air insures a good flamepattern.

The-stemT l1 of the burnertip memberiits Fuel oil passon the shell I0. A lock nut 34 serves to corn-1.

press a sealing washer against the end of the shell I6 and to anchor the shell in adjusted position with respect to thelsteam pipe .3L

The steam pipe 3l, oil pipe 26 and control rod 21 extend through an opening 36 providedin the wall 31 of a heater. The inner end 36 .of the steam pipe may be received within an opening A- 39 provided in the supporting body 40 and a threaded gland 4I and packing ring 42 provide va f fluid-tight joint. A set screw may be employed to secure the gland 4l to the steam pipe 3l. The inner end 43 of the oil pipe 28 isconnected by threads 44 to the body 46. The control rod 2.1 extends through the body 4S. Steam supplied through pipe 45 enters the body cavity 46 and passes into the interior of the 'steam pipe 3l. Fuel oil supplied by pipe 41 enters the body passage 48 and central cavity 49 and then passes around the control rod into 'the oil pipe 28.

Means are provided for adjusting the width of the fuel orifice 24 by moving the burner tip 'member I8 with respect to the deector member I4. As shown in Figure l this means includes a stationary calibrated disk 5| and va pointer collar 52 secured for turning movement with the control rod 21. The outer end ofthe rod 21 is threaded as shown at 53, and is received in the threaded hub 54. This hub is xed by means of threads 55 and set screw 56 to sleeve 51 which in turn is secured by threads 58 to the stationary body 48. A gland ring 59 encircles the control rod 21 within the hub 54 and engages a packing ring 60 to form a fluid-tight seal. Another gland ring 6I is threaded to the body 40 and serves to compress packing ring 62 to forma seal between the body 40 and sleeve 51. The calibrated disk 5I is fixed to the hub 54 by means of set screw 63. The pointer collar 52 is internallythreaded to receive the threads 53, and a lock nut 64 is provided to secure the pointer collar in adjusted position on the rod 21. When the pointer collar 52 and consequently the control rod 21 are turned the threads 53 on the rod turn within the threaded hub 54 and thus the rod 21 and burner tip member I8 are moved axially. The calibrations 6 5 on the disk 5I may beso related to the pitch of the threads 53 that movement of lthe pointer 66 from one calibration to the next corresponds to axial movement of the control rod 21 `for 0.001 inch. From this description it will be understood that the width of the fuel orifice 24 may be accurately regulated by turning the `pointer member 52 and the total width of the orifice may be indicated by the pointer 66 and calibrations 65.

The width of the steam orifice 26 may be set at any desired value by turning the shell Y I 0 with respect to the steam pipe 3l and -then locking it in adjusted position by means of the lock nut 34.

A.It is highly advantageous that the oil passing through the orifice 24V be *discharged in a continuous ribbon Without `breaks, or gaps. 4In order. -to'insure'thatthe oilreaches the orifice ina con-z constructions described is relatively short with 4 tinuous ribbon, we prefer to provide steam-to -oil dilution ports 61 which extend through the Wall of the deector member I4 at a location near the outer end of the burner assembly. These ports 61 communicate tangentially with the axial passage I6 so that a. swirling motion is imparted to the oil Within the passage I6 `by the steam which passes inwardly throughthe port 61. This swirling motion imparted to the oil causes the oil to cover all portions of the surfaces 2| and 22 so that the discharge fromthe fuel orifice 24 is in the form of a continuous ribbon. The thickness-of this ribbon Amay vary from a few thousandths ofan inch to a much larger value, depending onr theI quantity of oil required. The major portion of the steam passes through steam orice.y 26p and only a minor portion passes through ports 61. The more steam which passes` through the ports B1 in proportion to the steam passing through the steam orifice 26 has the effect of increasing the diameter of Jthe'iiame.

Fuel burners made in accordance with our invention remain clean for a much longer period of time than do conventional oil burners, because fuel drips do not form or accumulate. Should foreign matter clog the fuel orifice, it may be flushed away readily by moving the rod 21 in a direction to increase the width of the fuel orifice. Furthermore, steam may be admitted into the interior of the oil pipe 28. This may be accomplished through the provision Aof the valve assembly 68 which operates a closure 69 for the bypass duct 16 Within the body 40. When the valve 68 is opened by means of the operating knob 1l, steam ows from the body cavity 46 inwardly through the bypass duct 1I) into the central cavity 49 and then into the oil tube 28.

In the modified form of our invention shown in `Figure 7, the calibrated disk 5| is not used and instead a coil spring encircles the projecting end of the control rod 21 which extends from the exposed end of the sleeve 51. A gland 8I is threaded at 55 to the sleeve 51 and serves to move the ring 58 in a directionto compress the packing ring 60. One end of the spring 88 engages the gland 8l and the other rests against a collar 82. The collar 82 is held in position by a nut 83 threaded to the control rod 21. The action of the Yspring 86 is to move the rod 21 in a direction to reduce the size of the fuel orifice 24. This action of lthe springis opposed bythe pressure of the oil acting against the surface 2I on the burner tip flange 26. A higher rate of flow of oil causes the orifice 24 automatically to increase in width. This is a highly advantageous feature because the best atomizing action occurs at one flow ratefor any given oriiice size since the atomizing action depends upon the oil pressure producing it. From this description it will be-understood that the .burner tip member I9 floats with respect to the deflector member I4 sothat the Width of the fuel orifice -24 at any instant is determined by the spring 88 and the rate of flow of oil through the orifice.

The flame produced by either of the burner a wide pattern. The forward fiame velocity drops rapidly. Thisisof decided advantage in connection lwith the installations in fired heaters, boilers, -Aetc., where it is desiredto prevent impingement of the flame on-the far wall of the nre box.

Cleaning .of the burner tip isl accomplished very readily when Athatform of our invention shown in Figure 7 is employed...The operator need only 5 press the knob 84 at the end of the rod 21 in a direction to compress the spring,` Sii. The width of the'fuel oriiice is thereby increased, allowing any accumulation of foreign matter to be flushed away.

Having fully described our invention, it is to be understood that we do not wish to be limited to the detail-S herein setl forth, but our invention is of the full scope of the appended claim.

We claim:

In a fuel burner, the combination of; a tubular member' having an outwardly and forward- 1y extending flared circular lip at one end, said member having a central axial bore and an external cylindrical surface, the flared lip having a curved outer surface merging with said external cylindrical surface and a curved inner surface merging with said central axial bore, the said outer and inner surfaces on the flared lip tapering to a thin edge, said surfaces being substantially parallel adjacent said thin edge, an axially extending rod slidably mounted within ysaid bore, an outwardly extending head at one end of the rod `cooperating with said outer surface on the tubular member to denne a first ring orifice to emit a forwardly extending cone of atomizing uid, a shell mounted for axial sliding movement with respect to said tubular member, the shell lhaving a central bore, one end of the shell being shaped to cooperate with said inner surface on the tubular member to denne a second ring orice to emit a forwardly extending cone of fuel intersecting the cone of atomizing fluid, and means for supplying a fuel to one of said bores and an atomizing iluid to the other, whereby atomization of the fuel by the atomizing uid occurs on a full circle exteriorly of the lip between the forwardly extending intersecting cones of fuel and atomizing uid,

GERALD A. WHITE. LEWIS w. WILLIAMSON.

References Cited in the file of this patent UNITED STATES PATENTS Number