US2558779A - Oil burner - Google Patents

Description

July 3, 1951 J. D. PESCE 2,558,779

I OIL BURNER Filed Aug. 9, 1945 2 Sheets-Sheet 1 FIGJA J. D. PESCE 2,558,779

'OIL BURNER 2 Sheets-Sheet 2 JOSEPH D. P

July 3, 1951 Filed Aug. 9, 1945 @www Patented July 3, 1951 UNITED STATES PATENTl OFFICE OIL BURNER Joseph D. Pesce, Alexandria, Va..

Application August 9, 1945, Serial No. 609,901

2 Claims. (01.299-118.)

(Granted under the act of March 3, 1883, as amended April 30, :1928; 370 '0. G. 757) This invention relates to fuel burners for oil furnaces, and particularly to such burners designed for atomization of the fuel oil at several different rates.

In operation of oil furnaces, whether for marine boiler, utility power plant, or other purpose, present practice to a large degree involves the use of straight pressure atomization of the fuel oil. Since the amount of oil which may be eiiiciently burned by one burner is small, it is usual to employ burners of a standard size in sufficient numbers to supply the furnace with the required volume of oil to suit its load. Eiciency of combustion is desirable in any case, but is particularly sought in marine boilers which are designed for high horsepower for their size. Another practice is to cut out a number of burners to decrease the fuel burning rate. If these burners are not removed, their tips will be cloggedby coking of the oil. Changing the rate of a furnace is thus Subject to many objectionable operations.

In order to secure several different burning rates for each burner, present practice is almost universally to employ removable sprayer plates having different size orifices and associated whirling chambers. A certain adjustment of rate of burning may be achieved by variation of the pressure at which the fuel oil is supplied to the burners. When a rate not possible with a particular size spray or plate is necessary, ordinary procedure is to remove the sprayer plate and substitute for it in each burner one having a different size orifice. Expeditiously, `this vis often done by having 4a second set of burners Ain which the sprayer plate may be changed and the entire burners then quickly substituted for the ones removed from the furnaces. This applies particularly to marine practice where changes of load may be frequent and sudden.

It has been found, over a period of many years and through much experimentation, that the above described is the best available procedure yat present. This has not been due to lack of attempts to provide adjustable burners, but to the consistent failure of those devised to give eflicient and trouble-free service. In a given furnace, best results for burning the oil efficiently will be found when the cone of atomized oil includes an angle varying only within very small limits. Since this angle in the burners described is largely determined by the relation between the total cross-sectional areas of the tangential passages into the whirling chamber and the yarea of the orifice, no substantial changes in these fac- `operati-ng rod and fuel channel.

2 tors maybe allowed. An ordinary ratio between these areas is:

vide a burner 'capable of eflicient operation at several rates and obviating the necessity for fre- =1.0 (approx.)

-quent changing of Vburners with changes in the lead on -the furnaces.

A second object is to provide a multiple rate fuel oil burner incorporating the design features known tobe most eicient and'operating at each lrate in a manner identical 'with that in `which the present removable-sprayer-plate type burners operate.

A further object is to provide a burner achieving a plurality of burning rates by means ofy a plurality of self-contained atomzers telescoping within the burner tube and selectable by means which may be controlled from outside the furnace and without removing the burner.

These and other objects of the invention, and its advantages over present practice will be apparent as the description proceeds.

Figure l is a general view of the entire burner with a portion broken away to show the internal Figure 2 is Aa sectional view vin lseveral planes indicated by the lines II-II on Figures 3, 4 and 5.

Figures 3, 4 and 5 are sections taken along III-IIL IV-IV and V--V, respectively, of 'Figure 2.

Figure 6 isa view similar to Figure 2 but showing a modified form of burner.

Figure 7 is an venlarged view in section showing the details of the several orifices of the .burner shown in Figure 2.

Figure '7a is a modification of the details of Figure 7.

Referring in particular to Figures 2, 3, 4 and 5, 4the burner comprises a tube I. At the outer end -of the tube, there is provided a handwheel or handle 2 for purposes of adjustment ofthe rate of burning of lthe burner. 3 is an `inlet to 'be placed in communication with the fuel oil pressure system. The improved burner may be substituted for present ones.

Within the tube and controlled by the handle 2 is ya long loperating rod '4 extending almostto the inner end of the burner. At the inner (furnace) end of the tube there is a capA -5 which secures to the tube an oil distributing ring 6V and an `atomizer plate nozzle 8. -Distributing ringjE has on its outer surface a plurality of spacing ribs I which project at the outer end to space the main portion from the end of tube I. The ribs 1 do not extend to the inner surface of the distributing ring 6. The plate nozzle 8 has an orifice 9, which is the largest orice of the burner.

Within tube I an atomizer sleeve IIJ is telescoped. yRemovably secured to this sleeve is a cap nozzle II with its orifice I2. Within the sleeve I I! is a second sleeve I3 having a cap nozzle I4 with orifice I5. The above described two sleeves with their cap nozzles constitute second and third atomizers of diminishing size which, when in operating position, establish the second and third burning rates of the burner.

The mechanism for projecting the second atomizer nozzle II into operating position cornprises a pin I6 pressed into the shaft 4 and running in a slot I1 which extends for approximately 270 inside sleeve I0. The first half of the slot is on a slant so that rotation of the rod 4 causes the sleeve I to be pushed to the right, as shown in Figure 2. The latter 135 of the slot is normal to the axis. To restrain sleeve I0 from rotationy there is provided a key I8 which slides in one of eight axial grooves I9 cut into the metal of tube I.

A similar arrangement is `provided for moving sleeve I3. This comprises a pin 2U pressed into the rod 4 and a slot 2l which lies in a plane perpendicular to the axes for its first half and is at an angle thereto for its second half. Clockwise rotation of the rod 4 thus first translates sleeve IIJ withoutmoving sleeve I3. Further rotation then pushes sleeve I3 to the right. The displacement for each is the same, and equals the axial spacing of the cap nozzle II from the inner surface of plate nozzle 8 as shown in Figure 2. Sleeve I3 is prevented from rotation by means of pin 22`and slot 23. The inward extension of rib 1 referred to above maintains an annular passageway 24 between ring 6 and the end of the tube I. The ribs separate the main body of ring 6 from the inner surface of cap to provide channels 25. The cut-away portions of the ribs 'I leave between their ends and plate nozzle 8 a complete annular passage 26.

Fuel oil may thus pass from the inlet 3 through the tube and around the operating rod 4, through grooves I9 and passages 24, 25, 26. To supply oil to the whirling chamber of nozzle 8 a number of tangential passages 21 are out in its inner Surface.

The oil supply to the second orifice is by means of radial passages 28, and annulus 29 in ring 6 and tangential passages 3l] drilled in sleeve I0. To supply the smallest orifice I5, there are provided radial passages 3I and annulus 32 cut in sleeve I0 and tangential passages 33 drilled in sleeve I3. As indicated in Figure 2, passages 30 are out of registry with annulus 29. When the sleeve I0 is moved to the right to close the `whirling chamber shown, passages 30 are placed in communication with the oil supply. When then sleeve I3 is advanced its passages 33 will be in registry with 3I and 32. The whirling chamber Y34 of the smallest orifice is provided between the innery surface of sleeve I3 and cap I4 and the end of rod 4. Whirling chamber of orifice I2 is provided between the surfaces of cap nozzles II and I4 when the sleeve IU is advanced to the right into operating position (not shown).

The final passage of oil to each of the three whirling chambers isV by means of the three groups of tangential passagesY shown particu- 4 larly in Figures 3, 4 and 5. Each group is situated in a plane perpendicular to the axis of the burner tube I. Each arrangement of the burner for operation at the Vdifferent rates is thus independent of the other rates and is complete in itself. The number and total areas of the groups of tangential passages are fixed by the. design to conform to the required area ratio Y desired. Ihere is no intended adjustment of the rate for which a particular orifice with `its associated whirling chamber and tangential passages is designed.

Figure 6 shows a burner sectioned as the one previously described and shown in Figure 2. 'I'liis burner involves only two differently sized orifices and two rates of burning. It is in most respects like the three orice burner, and its component parts are referred to by like numerals. Its operation will be apparent from the description which has proceeded in connection with the preferred form of burner.

Figure 7 shows an enlarged section wherein the three atomizer nozzles are juxtaposed in the position in which the smallest of the three is in operation. The cone angle of the fuel is indicated at L to be the same for each orifice. This is subject to modification in the direction of establishing smaller cone angles in the second and third atomizer nozzles, if desired, as indie` cated by L. It is ordinarily deemed preferably to maintain particular cone angles in a given furnace installation and portions of the interior of the furnace are designed with that angle in mind. For example, the refractory immediately surrounding the interior end of the burner may be designed with rather a critical cone angle to secure proper distribution of the atomized fuel oil while allowing expansion of the gases in the flame. Obviously, it would be poor practice to vary the cone angle of the burner to any great extent, therefore, I contemplate equal cone angles for each burner atomizer. In this manner, one burner having several distinct rates of fuel atomization will t perfectly into a single burner assembly.

It will now be apparent that I have devised an improved oil burner avoiding many of the defects of those presently used while retaining the efiiciency of the best. Certain minor mechanical changes are possible within the limitations imposed by the appended claims.

The invention described herein may be made or used by or for the Government of the United States for governmental purposes without the payment to me of any royalties thereon or therefor.

I claim:

1. A burner for oil furnaces, comprising a tube; a, plurality of nozzles, one fixed at an end of the tube and the remaining telescoped within the tube; nonl-slidable, rotatable means operable from the opposite end of the tube for progressively moving the remaining nozzles into operating position adjacent saidY fixed nozzle, each nozzle when in operating position including a xed volume whirling chamber and fixed area orifice defined by cooperating surfaces of the nozzles, and oil passages substantially tangential to each whirling chamber located in axially spaced planes, the fixed volume of each whirling chamber and the fixed area of its orifice being different fromV that of` each other whirling chamber. 'l D l 2. A burner comprising a tube, a first atomizer nozzle iixedly secured at the end of the tube, a

non-slidable rotatable operating rod centrally located within the tube and arranged to be rotated only from the outer end of the tube. a sleeve and a second atomizer nozzle non-rotatably slidable with-in the tube to a retracted position wherein it cooperates to dene a fixed volume whirling chamber and a fixed area orifice for the first atomizer nozzle and to an extended operating position; and another sleeve and a third atomizer nozzle non-rotatably slidable within the second sleeve and on the rod to a retracted position wherein it cooperates to dedine a fixed volume whirling chamber and a fixed area oriiice for the second atomzer nozzle and to an extended operating position, the rod acting to move the second and third atomizer nozzles sequentially into the retracted and extended positions and cooperating to dene a xed volume whirling chamber and a fixed area orifice for the third atomizer nozzle; cooperating slot and pin means on said rod and Within each said sleeve, each said slot means being partially normal and partially angular to the longitudinal axis of said rod and extending not more than one revolution thereabout, the normal and angu- 2 lar portion of one slot means so registering with lfi angular and normal portion of the other slot means that rotation of said rod causes selective extension or retraction of either sleeve while the other sleeve remains stationary, each whirling chamber being supplied with oil by a group of tangential oil passages situated in axially spaced planes; the fixed Volume of each whirling chamber and the xed area of its orifice being different from that of each other whirling chamber.

JOSEPH D. PESCE.

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

UNITED STATES PATENTS Number Name Date 629,338 Chelimsky July 25, 1899 903,736 Lee Nov. 10, 1908 1,051,908 Normand Feb. 4, 1913 1,518,449 Plantinga Dec. 9, 1924 FOREIGN PATENTS Number Country Date 321,867 Great Britain Nov. 21, 1929

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