US2566040A

US2566040A - Fuel burning method and burner

Info

Publication number: US2566040A
Application number: US776303A
Authority: US
Inventors: Lawrence C Simmons
Original assignee: NEW YORK CENTRAL RAILROAD CO
Current assignee: NEW YORK CENTRAL RAILROAD CO
Priority date: 1947-09-26
Filing date: 1947-09-26
Publication date: 1951-08-28
Anticipated expiration: 1968-08-28

Description

Aug. 28, 1951 ..c. VSIMMONS 2,566,040

FUEL BURNING METHOD AND BURNER Filed sept. 2e, 1947 2 sheets-sheet 1 Srf/vM IN V EN TOR.

awrence Eim'mnns,

m W T m H l s v| .-c:. SIMMONS Y "FUEL BURNING METHOD AND` BURNER Aug. 2s, 1951 2 sheets-sheet 2 Filed Sept. 26, 1947- INVENTOR: Law/ferma C 'Emmm-Ls,

A Tro/P/vfy.

Patented Aug. 2 8, 1951 FUEL BURNING METHOD AND BURNER Lawrence C. Simmons, Ossining, N. Y., assigner to The New York Central Railroad Company, New York, N. Y., a corporation of New York Application SeptemberZ, 1947, Serial No. 776,303

5 Claims. l

This invention relates to fuel burners of that type designed for burning hydrocarbon fuels and in which jets or streams of the fuel are introduced under pressure with jets or streams of a gaseous combustion promoting or atomizing agent, such as air or steam, acting as a whirling medium, into a whirl chamber in which the fuel and such agent are caused to whirl before ejection and ignition of the mass in order to secure a high degree of atomization of the fuel and intermixture of the fuel with the atomizing or Y combustion promoting agent. More particularly the invention relates to a burner of this type which is of wide-range capacity and adapted to use the fuel and atomizing or combustion promoting agent at low pressures and in such manner as to place the fuel in a highly atomized or divided state for consumption.

The invention also relates to a novel method of atomizing or finely dividing fuel by means of a gaseous whirling agent to form a highly combustible mixture.

Heretofore it has been the practice to employ |.burners of this type having a single set of tangential slots for introducing the fuel and whirling medium into the whirl chamber, the slots being of milled formation. Burners of this type are to a certain extent costly, owing to the amount of care and precise machine work required in milling the slots, and furthermore have not been of a desired high degree of eiciency in operation, due to the fact that slots of the exact dimensions necessary to secure a proper proportional admixture of the fuel and whirling medium and whirling velocity and degree of minuteness of atomization of the Vfuel could not be accurately produced by milling, resulting in incomplete combustion and waste of fuel and the deposit of products necessitating frequent cleaning of the burner.

It has also been a practice heretofore to inject streams of oil and gas into a whirl chamber so as to cause the mixed streams of oil and gas to whirl and move axially toward the outlet of the chamber, either by introducing the oil with the gas into the chamber through a single set of tangential passages, in which case the gas blows through the oil, with high ejection velocity, but with a loss of whirl velocity, thus causing the production of a long and unstable flame, or by introducing streams of gas into the chamber through one set of tangential passages, which streams set up a whirling motion of the mixture, and axially injecting streams of gas into the chamber at its inner end or through one or more 2 additional sets of tangential passages, Vacting on the mixed streams as they issue at the outlet end of the chamber, and inclined circumferentially in the opposite direction to the first tangential set of passages, in which case the whirl velocity is also reduced so that choking occurs and the action is a mixing action, causing the production of a conical stream containing non-atomized particles of the fuel at the burner outlet rather than a highly atomized hollow cone shaped spray. In each of these cases there is a loss of gas energy which is reduced or dissipated in turbulence so that a whirl velocity and centrifugal force within the whirl chamber of a sufficiently high degree to atomize the fuel in the whirl chamber and cause the production of a stabe hollow cone shaped spray at the burner outlet cannot be obtained.

The main object of the present invention is to provide a burner which overcomes these objections to prior burners, and by means of which a precise supply of the fuel and whirling medium at the exact velocity for a highly efcient whirling action to atomize the fuel may be continuously produced and introduced into the whirl chamber. y

A further object of the invention is to provide a burner embodying these and other working advantages, as well as greater convenience and economy of manufacture,YV by the use of bored slots or passages instead of milled slots.

A still further object of the invention is to provide a burner having a plurality of rows or sets of bored passages relatively dimensioned and arranged to secure accuracy in the supply of the fuel and whirling medium in proper proportions and at the velocity necessary to ensure a most eiiicient whirling action and atomization of the fuel for perfect combustion, while at the same time effecting a savingin steam or air consumption.

A still further object of the invention is to provide a whirl type of burner which may be readily designed to whirl and burn hea-Vy liquid hydrocarbon fuels as well as to spin a solid hydrocarbon fuel, such as powdered coal, so that such fuels or coal may be efficiently and economically used with a burner of this type.

A still further object of the invention is to provide a burner structure embodying means for intermixing the fuel with a whirling medium in successive stages at spaced points axially of the whirl chamber, thereby producing a more intimate mixture and a higher degree of velocity for the whirling action in the whirl chamber.

A still further object of the invention is to provide a low pressure method and burner whereby a whirl velocity substantially equal to that of a mechanical pressure atomizer may be btained, and whereby the pressure of the gaseous whirling agent is fully utilized to whirl the mixture of fuel and the gaseous agent within the whirl chamber ata s uiciently high velocity and centrifugal force in the whirl chamber to atomize the fuel therein and produce a stable hollow cone shaped spray of finely divided fuel particles at the burner outlet. Y

Still another object of the invention is to provide a novel method of conditioningthe fuel to produce a combusti-ble mixturewithout leaving any material amount of residue requiring frequent cleaning of the burner...I

With these and other objects in View, which will appear in the course of the subjoined description, the invention consists of the novel steps of the method `and novel features of construction, combination and arrangement of parts, hereinafter fully s e't forth and claimed, and as shown in the accompanying darwings, in which:

Figure l is an end elevation looking toward the ejection outlet of the burner tip or atomizer of a fuel burner embodying my invention.

Figure 2 is a Yviei'v Vin side elevation of the burner assembly.

Figure 3 is an irregular vertical longitudinal section on an fenlargedscale through the burner assembly, the 'section being taken on an irregular line through the forward end of the burner casing and the burn'er tip to more clearly show the arrangement 'of the fuel and gas feed channels.

Figures 4, f5., 6 and Z 'are transverse sections taken, respectively, von the Vlines 4-4, 5 5, B-E and 'I-l of Figure 3.

Figure 8 is `a crosss'ecti'on through the burner tip or atomizer taken on the line '8-8 of Figure 9.

Figure 9 is apart sectional and part side elevational view of the burner tip or atomizer, the section being taken'on line `9`9 of Figure 8.

Figure l0 is a perspective View of the feed plug.

Referring now 'moieparticularly to the drawings, I designates the burner casing or tube, and 2 the burnerftube cap having an inwardly extending flange '2 defining air outlet opening 3 at its forward end.

Mounted withintl'eburner tube or casing and spaced from vthe sidewalls thereof is a fuel conducting pipe orftube -4,'thr'o'u'gh the bore or passage of which the fuel to be atomized, such as oil, for example, -i's'c'onducted toward the burner tip at the discharge end of the burner. The space between thetubes I and i4 'provides an annular passage 6 for'thelow ,ofthe gaseouscombustion-promoting, atomizing or whirling vInedium, such as air 'or steam, to the'burner tip.

The bore 'or passage of the conductor 4 is counterboredcr recessed at its forward end, as at 1, to receive a'hollo'w oil feed'plug 8. This plug has anopen rea-rend communicating with the passage 5 and is closed at its front end 9, the latter having 'aplane front face I0 lying flush with the forward end of the tube 4. The forward portion of this plug is externally reduced in diameter, as shown at II. to form with the opposed portion ofthe lwall of the recess 'I a shallow, annular oil delivery' passage I2 opening outwardly about the face I0 of the plug. Formed in the plug is an' annular set or series of equally spaced radial feed 'parts I3 which communicate at their inner ends with the interior of the plug and at their outer ends with said oil delivery passage I2. Oil under pressure may thus Iiow from passage 5 into the plug and outward through the ports I3 to the passage I2 for supply in a regulated amount to the burner tip or atomizer I4.

The burner tip or atomizer I4 is disposed between the forward end ofthe conductor 4 and the inwardly extending flange 2 at the front of the cap 2. This tip is of generally circular form and has a body portion I5 of less diameter than the internal diameter of the cap 2 but of greater diameter than the portion Il of the plug 8, a front face I6, a rear face I1, and a central passage IB forming4 an elongated whirl chamber. The front face I6 of the tip is arranged to bear against the flange ,2" of the cap 2 and adjacent thereto the tip is provided with a circumferential flange I9 which bears against the inner periphery of the cap and spaces the body portion I5 of the tip from said surface of the cap. The rear face I1 of thetip is varranged to bear against the front end of the conductor 4 and the frontface I0 of the plug 8, and extending rearwardly from this face I'I of the tip 4is a flange 20 which overlaps the reduced front portion 2l of the conductor 4 and centers the tip with relation thereto and to the plug 8.

The burner tip is provided in its rear vportion with a set of fuel and air or steam conducting channels or passages 22 and at a suitable point between said channels 22 and an ejection outlet 23 at the front of the whirl chamber I8 with a set of air or steam conducting channels or passages 24, the channels of each set extending from its periphery toward and entering the whirl chamber substantially tangentially thereto. The channels of each set are formed by boring or drilling them in contradis'tinction -to milling them, by which they vmay be "more economically produced and also more 'accurately `dirnensioned for fuel and steam supplies in proper ratios and arranged to secure 'a more efficient whirling aotion and atomization of the'oil. At least two sets of channels are `provided forthese purposes, one for mixed jets of oil and air or steam and the other for vjets of air or steam alone, to make up for reduction in the sizes of the channels necessitated by drilling 'and which in the use of a single set might cause undesirable restriction to steam flow. Any number of sets or rows of Vbored channels, suitably dimensined and placed at spaced points axially of'the tip,may -be Aused to increase the whirl velocity and adapt the'burner to atoinize heavy hydrocarbon oils `vor to spin powdered coal at the velocity necessary to useit as'fuel. In the present instance'two such sets or rows of channels are"discl'osedtosecure feed and velocity ratios sufficient for theiine atomization of hydrocarbon oil of a certain viscosity, but by the use of1 one'or more additional rows velocities sufficient foratomizationl of 1'heavier hydrocarbon oils 'oi"`to"spin powdered coal may `be obtained.

In the construction illustrated the channels 22 are arrangedat the inner'end ofthetipand'consist of circular 22f bores formed in the flange 2% and aligned grooves 22aforred in the face II extending from the ange to 'theinnerend zof the chamber' I8, whilethe channels'24 Vare in the form of continuous 'circular 'bores extending from the outer periphery'of the tip to and intersecting the chamber I8 at a point between .the grooves 22a and the ejection outlet23. As shown in this vparticular .instance the channels 2li-intersect the chamber I8 at a point somewhat in advance of its transverse center and between its transverse center and the outlet 23, but this arrangement may be varied as circumstances may require. The grooved portions of the channels 22 are closed at the rear by the surface II) of the plug 8 and communicate with the oil'feed passage I2 at a point between their outer ends and the chamber I8, while both sets of

channels

22 and 24 communicate at their outer ends with the steam passage 6. While steam has been more particularly described above as the atomizing, combustionpromoting and whirling medium used, it is to be understood that under certain conditions or for ,certain installations air, air and steam combined, or any suitable gaseous whirling medium may be employed. The outlet 23 tapers to a degree not suiiicient to reduce the outlet end of the chamber to a diameter materially impeding the outward flow of the fuel mass, but only to a degree to slightly check the flow of and concentrate the fuel mass at its point of discharge and to produce a guide surface converging toward an exit edge over which the fuel may flow to form a hollow diverging conical spray.

`In the operation of the burner, the liquid fuel to be atomized is supplied continuously to the passage 5, from which it flows into the plug 8 and through the ports I3 in the latter to the annular passage I2, from which it is delivered into the channels 22 at an intermediate point in the length of each of said channels. At the same time low-pressure steam or air ilows from the passage 6 into both sets of

channels

22 and 24. The'streams or jets or steam or air entering the channels 22 pick up and are intermixed with the fuel entering such channels and these streams are commingled and flow in a commingled condition into the whirl chamber I8 at a high initial .velocity and are caused to whirl therein by which a high degree of atomization of the fuel is effected. This whirling mass moves axially in the tip toward the ejection outlet 23 and meets the streams or jets of steam or air entering the tip through the channels 24. vAs these stream or jets, entering through the channels 24 in the same direction circumferentially of the chamber as the streams injected by the channels 22, strike the whirling mass after it has already obtained a high velocity due to injection through the channels 22, the mass is whirled continuously in the same direction but at a still higher velocity whereby the atomizaticn of the fuel is increased and effected in the whirl chamber to a much higher degree than is possible to obtain with burners of the ordinary type using milled slots or prior methods causing loss 'of' gas pressure or choking or turbulence of the mixture in the whirl chamber. This is due to the fact that the efficiency of a jet is a function ofthe speed of a mass it is required to move. yBy the provision of air or steam injection channels 24, which inject the added streams of gas into the whirl chamber in the same direction circumferentially as the channels 22, the whirling speed is not only greatly increased, with a resulting higher centrifugal force producing a higher degree of atomization, but the whirling agent, air or steam, is more intimately admixed with the minute oil globules, so that a fuel mixture of maximum combustiblity is produced. This mixture feeds in the form of a slightly converging conical mass to the conical outlet 23 and then discharges in the form of a diverging stable, hollow conical stream through the burner outlet, where it is suitably ignited.

member in advance of the plug, said tip having` The result of atomizing the fuel in the manner" described is to provide a method of atomization which effects a saving in steam or air consump-V tion and reduces liability of irregularities of ac-v tion of the burner and furnishes a highly combustible fuel which will leave less residue, so that frequent cleaning of the burner is unnecessary;- By increasing the number of rows of air or steam'. jets employed, the whirl velocity of the mass inthe whirl chamber may be increased to degrees- .allowing atomization and burning of heavy liquidhydrocarbon fuels as well as the spinningland mixing of powdered coal with a whirling andcombustion-promoting agent, so that low gradef liquid hydrocarbon oils and powdered coal may' be used as fuel with this type of burner.

While for purpose of disclosing one form of embodiment of my invention I have shown thev channels of the

sets

22 and 24 as similarly dis-- posed about .the burner tip and having the discharge ends of their similarly arranged channels opening into the whirl chamber in line with each other axially, of the chamber, it is to be understood that the channels and their delivery ends may be staggered or otherwise arranged with relation to each other so long as their functional characteristics hereinbefore described are preserved. In some cases also it may be found desirable to feed portions of the fuel with the gaseous whirling medium into the whirl chamber through both sets of

passages

22 and 24, and hence I do not limit myself in this particularly except when specifically set forth inthe claims.

From lthe foregoing description, taken in connection with the drawings, the construction, mode of operation and advantages of my invention Iwill be readily understood without a further and extended description. While the structural features shown are preferred, it is to be understood that changes in the form, arrangement and details of construction may be made within the scope of the appended claims, without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus described my invention, I claim:

1. A fuel burner including in combination a fuel conductor, a member enclosing said conductor and spaced therefrom to provide a gaseous agent supply conductor, a fuel feed plug fitted in the forward end of the fuel conductor and peripherally spaced therefrom to form a fuel feed passage, said plug having radial ports communieating with said passage, and a burner tip arranged between the fuel conduit and enclosing member in advance of the plug, said tip having a whirl chamber provided with an ejection outlet at its forward end, a set of tangential passages at its rear end communicating with the gaseous agent conduit, fuel passage and whirl chamber, and a set of tangential passages arranged between the rst-named passages and the ejection outlet of the whirl chamber and communicating at their outer ends with the gaseous agent conduit and at their inner ends with the whirl chamber. Y

2. A fuel burner including in combination a fuel conductor, a member enclosing said conductor and spaced therefrom to provide a gaseous agent supply conductor, a fuel feed plug iitted in the forward end of the fuel conductor and peripherally spaced therefrom to form a fuel feed passage, said plug having radial ports communicating with said p'assage,` and a burner tip arranged between the fuel conduit and enclosing accanto a whirl chamber provided with anejection outlet at its forward end and closed a-t its rear end by the plug, a set of tangential passages at its inner end communicating with thel gaseous agent fuel conduit, fuel passage andl whirl, chamber, and a set of tangential passages arranged between the first-named passages and the ejection outlet of the whirl chamber and communicating at their outer ends with the gaseous agent conduit and at their inner ends with the whirl chamber.

3. An atom-icing burnerineluding--in combination a fuel supply conduit, a gaseous agent supply conduit, andl a burner body having a longitudinally extending whirl chamber having front and rear ends and providedwith an atomized f fuel discharge orifice at its front end, a set of tangential passages communicating at' their inlet ends with the fuel supply conduit and opening at their discharge ends into the rear endof the whirl chamber,v said rear-endof the whirl chamber being closed against the admission of fluid except through saidl tangential passages, and a second set of tangential passages communicating at their inlet ends-with the gaseous agent supply conduit and opening at their discharge ends into the whirl chamber tangentially in the same direction as the first-namedpassages, said discharge ends of thesecond. named set of passages heilig arrangedl to` open directly into the whirl chamber at a point locatedraxially of the chamber forwardly orr the- 'rst named passages and rearwardly. ofl the discharge orificeV at the forward end of the'chamber, said orice being of a diameter at its inner end portion-corresponding substantially to that of thechamber and converging therefrom to a slightly less diameter at its outer end portionand` terminating at its outer end portion in an end edge-over whichv the atomized fuel may discharge-in therformfof a hollow diverging conicalJ stream.

4. An atoiniaingv fuel burnerl including in combination a fuel supply conduit, a gaseous agent supply conduit, and atuirnerA bodyhaving a longitudinally extending whirl chamber provided with an atomizedrfuelwdischarge or-ice at'its forwardv end, a. set` of tangentialpassages formed in the burner body:andicommunicating at their inlet ends with said conduitsv externally of the 'whirl chamber and. opening attheir: discharge ends .into the rear of.'v the whirl-chamber for supplying tothe chanibcrstreams-oflffuelfmixed with the: gaseous agent: priorV to their discharge` into the chamber, and a-second setLof tangential passages formedf inthe burner bodyVa-nd-v communicatingat vtheir, inlet ends-with the gaseous agent .supplyA conduit and opening-at. their discharge ends into the whirl chamber tange-ntially inthe same Adirection asgthefirst namedpassages, said discharge ends ofthe second-set off' passagesbeing arranged to open directly--A into the wh-irl chamber at a point,locatedaxiallyfof the chamlill ber forward of and in spaced relation to the rst named set of passages and in rear of the inlet end of the discharge orifice at the forward end of the chamber, said orice being of frustoconical form and converging from a diameter substantially equal atl its inner end to that of the chamber to a diameter at its outer end slightly less than that of the chamber, the latter named end portion being formed by a flange on the burner body which terminates in an end edge over which the atomized fuel may flow in the form of a hollow cone.

5. The low pressure method of obtaining a high whirling velocity to fuel and a gaseous agent in a cylindrical whirl chamber having an outlet end for discharge of the atomized fuel, to produce a. fuel mixture compris-ing interspersed particles of the gaseous agent and finely atomized particles of the fuel globules, which consistsin mixing streams of fuel with gaseous streams outside the chamber, introducing the previously mixed fuel and gaseous streams tangentially into the'charnberA at a point remote from its outlet so as to cause said streams to spirally whirl at a predetermined speed and centrifugalV force circumferentially of theV chamber toward the outlet, introducing other gaseous streams tangentially into the chamber closer to the outlet than the point of introduction` of the i'lrst named streams but axially of the chamber at a point also remote from the outlet, causing said streams to mingle with the first named streams and spirally whirl unidirectionaliy therewith toward the outlet at a Velocity and centrifugal force progressivelyin'- creasing toward the chamber outlet so as t0 minutely disrupt the fuel and intimately the gaseous agent therewith, causing the mixturek to slightly converge and to be slightly checked in its flow asit enters the outlet, and then releasing it and permitting it to freely discharge as it leaves the outlet in the form of a hollow diverging conical stream.

LAWRENCE C. SIMMONS'.

REFERENCES CTED The following references are of record in the le ofl this patent:

UNITED STATES PATENTS Number Name Date 1,023,707 Anthony Apr. 16, 1912 1,381,695 Starr June 7, 1921 1,451,063 Anthony Apr. 10, 1923 1,973,781 Nightingale Aug. 23, 1932 FOREIGN PATENTS Number Country Date 97,936 Switzerland Feb. 16, 1923 409,211 Great Britain Apr. 26, 1934 419,949 Y GreatBritain' Nov. 19, ..1934