US2284708A - Fuel burner - Google Patents

Description

E. L. WOOLLEY June 2, 1942.

FUEL BURNER led Deo. 19, 1939 3 Sheets-Sheet l Il: la'

,lay

Jun 2, 11942. E. L. woQLLEY l l 2,284,708

FUEL BURNER Filed Dec. 19, 1959 s sheets-Sheet 2 Ergly i I i@ /'z'jizzze'yr June 2, 1942. E. l.. wooLLEY 2,284,708

'FUEL BURNER Filed Dec. 19, 1959 3 Sheets-Sheet 3 Patented June 2, 1.942

QE'FIJCB *i 'FUEL BURNER. Ernest LfWQolley, Providencc,1. Y 9 Alipiiaaonnecmber 19,1939, seria Naeoaem A niclaims. (ci. 11o-422) This invention relates to improvements in fuel` burners `I? the type illustrated anddescribed in! separately or in conjunction. i

Another objectofjthe invention isfto provide an apparatus of the type indicated adapted to supply adequate primary and secondary air to the burnerI for insuring complete combustion of the liquid fuel and/or amixed -charge ofpow` dered fuel and air.-

`Another object of the invention is to provide an apparatus` of the type indicated in which the primary airfor the'liquid` fuel maybe shut off simultaneously with the admission of themixed charge of powdered fuel and airuto the burner.

Another object Vof the invention is to provide an apparatus of the typ indicated having means for controlling4 the supply of primary and secondary'air independently of the means for shut' ting 01T the supply of primary air. Y

Still another' object of the invention is to provide an Aapparatus ofthe type indicatedV which is efficient `in operation and` of simple, compact and rugged ,construction to-adapt i'tfor use over long periods of ytimewithout repair or replacement'of parts,v Y t Further objects of ltheinvention are set forth in `the following specification which describesa preferred form of construction of the apparatus, by way off'example,V asiillustrated byv theaccornpanyins; drawings. ln: the drawings:

conduit for supplying` powderedfuel `open and the intake for the primaryair closed.

"The present apparatus comprises` generally a casing .constituting an` air lregister and 'having two or more concentric` annular throats for supplying primary and secondary air to promote combustion of the fuelwith dampers in each throat for controlling the amount of air supplied therethrough. A supply pipeY for liquid fuel extendslongitudinally of the casing .in the inner throat and has a burner-tip at itsend.` The casing has separate apertures at its periphery: for supply-ing primary air for the liquid'fuel andA a mixed charge of powdered fuel and air. Valve: means are also provided for simultaneously closing the apertures. for supplying primary airjand opening .the aperture for supplying a i mixed charge of` powderedfuel and air, `for vice versa.

Fig. 1` is ,ai vertical sectional `View `througha. f

conventional type, of f boiler front wall showing the `present improvedburner applied to the opening therein; 1

Fig. 2 is an.` end viewof the burner illustrated in Fig.1 `1 showingthe liquid fuel supply pipe at the Vaxis of `the burner and a conduit at the periphery Referring `to Fig.` 1 of the'drawings, 2 designates the `masonry forward .'wallV of a Vboiler furnace which is coveredfby.v an outer shell or front .plate.3. `The present improvedburner is preferably-embodied in a Vunitary casing adapted to be attached to lthe front [of the boiler furnace and serving` as the means for supporting fuel supply means and also the controls thereof. As herein `shown the burner-casing comprises an annular sleeve 5 of slightly tapered form adapted to fit closely within thewopening 6 in the front of the lfurnace and formed with a radial flange 'I atits outer end. The annular sleeve ormember 5 is'provided with perforated ears or lugs 8` on itslperiphery which receive studs 9 projecting from the furnace front plate -3 with nuts screwed onto their ends to secure the sleeve fixedly in position. The sleeve 5 forms theouter boundary wall ofthe larger throat of the air register and cooperating therewith is `an inner.. concentric annulus I0? which forms a secondv internal throat. The inner annulussIO is providedw'ith a` radial flange I Ii at its outer-end which projects radially beyond the flange 1. Thev flange I I may be continuous and integral with the annulus HLbut'as herein illustrated it is `made in two parts `spaced from each other to provide an annular slot I2` therebetween, see Fig. 4.` The space between the flange 'I on the annulus 5 and the flange II of the annulus Ill serves as the inlet opening or intake I3 for 'the- `secondary air ,which is admitted through the.

closure-plate I4 and the flange II of the annulus I to support the latter and hold it in its proper relation to the sleeve 5. Thus, the space between the flange II on the annulus I9 and the closureplate I4 serves as the inlet opening or intake I9 for the primary air admitted through the inner throat.

A series of arcuate vanes I6 are pivoted on the bolts I between the flange 1 on the sleeve 5 and the flange II of the annulus I0 to adapt them to be rocked or swung to vary the area of the intake I3 to control the volume of the secondary air current introduced through the outer throat or to entirely close the intake. A series of similar vanes I1 are pivoted on the bolts I5 between the flange II on the annulus I0 and the closureplate I4 to adapt them to be rocked for varying the area of the intake I9 to control the volume of primary air introduced through the inner throat. y

The construction and arrangement of the vanes I6 and I1 are illustrated and described in detail in my prior patent referred to above. Suffice it to state herein that the series of vanes I6 and I1 are operated in sequence by means of a ring rotatable in an annular `recess 2| in the closure-plate I4 and having a series of pins 22 extending longitudinally of the casing through the arcuate slot I2 in the radial flange II of the annulus I0. Each of the vanes I6 and I1 has a depending flange 23 with a slot 24 through which the pins 22 extend, see Figs. 4 and 5. Although the slots 24 may have other forms, as herein illustrated they comprise an arcuate portion with a right-angular continuation at one end with the right-angular portions reversed in position on the respective vanes I6 and I1 as shown in detail in my prior patent referred to above. Thus, upon rotation of the ring 29 the series of pins 22 first act in the radial slots 24 in the vanes I1 to rock them to the open position illustrated in Figs. 4 and 5 to open the primary air intake I9 to the inner throat. Continued rotation of ring 20 causes the second setof vanes I6 to be rocked to open position while the pins 22 slide in the arcuate portion of the slots 24 to hold the vanes I1 open. The ring 20 has a series ofgear-teeth on its periphery `in mesh with the teeth of a gear 21 shown in Fig. 2. The gear 21 is keyed to one end of a shaft 28 having a crank-handle 29 at its opposite end for rotating the gear in either direction to turn the ring 20 to operate the vanes I6 and I1.

In accordance with the present invention a casing section 32 of generally circular contour and U-shaped in cross-section cooperates with the flange Il of the annulus I0 and closure-plate I4 adjacent their outer peripheries to provide an annular chamber 33 surrounding the intake I9 for the inner throat. As illustrated in Fig. l, the casing section 32 is connected to the end closure-plate I4 by means of a ring 34 Welded or otherwise fastened to its inner annular Wall and having an angular flange bolted to the plate I4 by the studs I5. The casing section 32 is further connected to the ange II of the annulus Ill by means of a. series of arcuately-shaped anglebrackets 35, see Fig. 4, Welded or otherwise suitably fastened thereto. Preferably, the casing section 32 is of gradually tapering width from top to bottom for a purpose as will appear later. The casing section 32 has a series of spaced apertures or openings 36 in its periphery, see Figs. 1 and 3, and an annular rim or bead 31 at one Side of the openings which cooperates with the outer rim of the flange II of the annulus I0 to provide an annular guideway 38 encircling the openings. The casing section 32 is provided at the top with a conduit 39 flanged for bolting a fuel feed pipe or chute 40 thereto as indicated in Fig. l.

The supply pipe 42 for liquid fuel is mounted on the end closure-plate I4 and extends axially of the annulus I0. As herein illustrated the supply pipe 42 is supported in a tube 44 by means of a spider 43 having a hub which closely lits the pipe and arms which engage the interior of the tube. The tube 44, in turn, is slidably mounted in a sleeve 45 on the closure-plate I4 to adapt it for adjustment longitudinally of the annulus I6. The tube 44 also serves as an additional air-pipe surrounding the fuel-pipe 42 for supplying a small amount of air to the burner. A burner-tip 46 for the liquid fuel is carried at the inner end of the supply pipe 42 and a diffusion plate 41 is supported at the end of the tube 44 surrounding the burner-tip. The outer end of the supply pipe 42 is clamped to a fitting 48 connected by a pipe 49 to a source of liquid fuel supply in the usual manner and the fuel supplied to the burner is controlled by a manually-operable valve 50.

In addition to the liquid fuel, solid fuel may be supplied to the burner through the conduit 39 and intake opening I9 by way of the inner throat. The solid fuel is introduced as a mixed charge comprising powdered coal suspended in an air blast from a blower, not herein shown. Thus, the primary air for the combustion of the solid fuel is supplied therewith so that when powdered coal is used the openings 36 in the casing section 32 for supplying primary air to th-e inner throat are closed.

Valve-mechanism is provided for simultaneously closing the air intake openings 36 and opening the conduit 39 in the casing 32, and vice versa. As illustrated herein the valve-mechanism comprises a ring-closure 54 surrounding the primary air intake openings 36 and a butterflyvalve 55 in the conduit 39. 'I'he ring-closure 54 fits closely in the annular guideway 38 on the casing-section 32 and has a series of openings 56 of the same shape and spaced from each other the same distance as the openings 36 in the casing-section. Thus, when the ring-closure 54 is moved to the position illustrated in Fig. 4 the openings 56 therein aline with the openings 36 in the casing section 32 to admit air to the intake I9. When the ring-closure 54 is moved to the position illustrated in Fig. 5 the openings 56 and 36 are oifset to lclose the intake I9.

The butterfly-valve 55 in the conduit 39 is of rectangular shape to conform to the interior con tour of the conduit, being carried' by a stem 59 extending through bearing apertures in the sides of the conduit, see Figs. 1 and 3. vAs illustrated most clearly in Fig. 1, the stem 59 for the valve 55 extends rearwardly from the conduit 39 above the ring-closure 54 with its end journaled in a bearing 60 supported on the flange II of the inner annulus I0. A gear 6I xed to the rearward extension of the stem 59 meshes with the teeth 53 of a rack 51 fastened to the ring-closure 54 to operate the latter and the stem may be turned by a crank-handle 62 mounted on its outer end. The ring-closure 54 and butterfly-valve 55 are so arranged with respect to each other that when one is in open position the other is in closed position and the gear 6I and rack 51 on the ringclosure are so proportioned that aquarter turn fromthe` position shown inFig. -4 to'that"V shown in Fig. `5, orviceversa. One embodiment of the invention 4having; nowv `been described in detail; the mode'fofoperationfoftheburner is explained as follows:v

i The present "improvedf burnerA isgadapted to burnlioluid` fuels such as-oil, orcoznminuted fuels suchas powdered coal, either separately'or in conjunction. When a cold boiler is to lbezstarte'd` theft ring l 2U isl rotated `-by means "of the lcrankf handle]` 29" to lc'auseithelpins* A22 extending from the ring Lto engagethe right-angular portionsvof the slotsV 24A inthe `depending flanges -23 of the operi'u `the intaltefthroat I9; The f ring-closure 54 isalso Yoperated bymeans :of the crank-handle t'i-IeftoV the position shown in Fig. 4 to uncover the opening'sii inthe casingsection -32 to'admit primary air through theintake `ISI "toJ the inner throat: i f l AThe control-valve Edforthe liquid fuel Supply pipe 42 thencrackedt permitV a relatively smallicharge of oil to be ejected frcmythe burnertipjilIGifwhichisignited by `a. torch or the like.

The vanes Iii-'and 'I1 are then adjusted by Amaf this -beingiofadvantage to avoid overheating the` burner-tip.I Thus,` the" iiame and products of combustion produce a* relatively'low heat rin the furnace-toslowlywarm up the boiler and the amount-ofV fuel -andrprimary and-secondary air `are gradually increased *from time-to time` until the boilerA is thoroughly heated.

The fuel `supply maythenV be changed to powdered fuel. Toithis end the crank-handle 62 is operated to rotate the stemv through a quarter turn which operates to simultaneously rock the butteriiy-valve 55 to openthe conduit 39` and turn the ring-closure 54 to close the openings 35 in the casingsection 32Kas illustrated in Fig. 5.

controlled by the`Y` vanes I5. In lthe preferred methodgor operation, however, afterlthe Amixed i charge of powdered fuel has `been ignited lthe supply `of liquid `fuelis shut off by,manipulating.they

valve n50. :The apparatus `thereafter `operates as afpowdered'fuelfburnerw "ff l l Bysliding `the-tube `44'-in itssupporting-sleeve Jon# the end-closure fI4j`` the area of the annular! 'opening between the! diffusion plate '4l `and tlieend'o'flthe inner -annulus I5 maybe varied to' 'control thefpattern of Vtheviiame; -Likewise, the supply of secondary air may be' controlled byfmanipulating the crank-handle `-29to rock the vanesf IB? and? thereby lva'ryf the areaI of f the airintake-i315. It `will be L'inder'stoodfthat for overload conditionswthe oilburner mayv be brought in to complement the burning of the powdered fuel.

Itvwillwbeobservedfrom the foregoing specication Vthat Athe present invention provides a burner of *novela construction adapted Lto "burn bot-h liquid andpowdered fuels 'feitherseparately or in conjunction; It will 'also beobserved that the improved apparatusprovides means-for controlling the amountof primaryandsecondaryuair supplied when liquid fuel isfused and independentmeans,lforf'simultaneouslyshutting offA the primary A-air supply andadmittinga mixedcharge Yso of powderedfuel and air `to'convert the device toapowderedfuel-burner: Y

While 'afpreferred embodiment of the 'inven- Ation is `herein described 'and illustrated, it will casing, ra fburnenfor' liquid fuel inthe casing,

means for `supplying airfto the casing; a 'conduit for supplying a mixedcharge [of powdered fuel and air tothe casing; and' YIn`eansfor simultaneously cutting off the rst mentioned air supply and opening the conduit for supplying a mixed l charge of powdered fuel and air, or vice versa.

As stated/above, rotation of the crank-handle 62 rocks the butterfly-valve 55 and rotates the gear 6I on the rearward extension of the stem 59 which meshes with the teeth 58 on the rack- -51 to operate the ring-closure 54.` Thus, the sup-Y ply of primary .air to the throat I9 is shut off and a mixed charge of powdered fuel and air is introduced into the casingsection 32. The mixed charge of fuel and air passesV through the intake I9 and inner throat and discharges into the furnace through the opening between the end of the inner annulus Ill and outer periphery of the diffusion plate 4'I. As the mixed fuel charge strikes the flame it isignited, suihcient primary air being supplied Vwith the powdered fuel to in- Vsure combustion. Dueto the tortuous path' of the mixed charge of powdered fuel and air through the pivoted vanes I'I a high degree of turbulence is produced therein vwhichinsures practically complete combustion. Furthermore, the tapered form or funnel-shape ofthe involute casing-sec- 2. In an apparatus of the type indicated, an annular casing, a `burner for liquid fuel at the axis ofthe casing, means at the periphery of the casing for supplying air tosupport combustion of theliquid fuel, a `conduit at'the periphery of` the casing for supplying ay mixed charge of powdered fuel and air, and valve-means forsimultaneously cutting off the air supply and opening the conduitfor supplying a mixed charge of powdered fuel 'and air.

. 3. In an apparatus of the type indicated, a Y casing having two separate inlets, one of said 4. In -a-device of the type indicated an an nular casing having a series of openings at its periphery for supplying air to the interior thereof a ring-closure rotatable on the casing for closing the series of openings, a conduitKV atfthe peripheryvof the casing for supplying a mixed charge of powdered fuel and air, a valve for opening and closing the conduit, and

manually-operable means forV simultaneouslyV rotating the ring-closure to closing position on the casing and opening the valve in the conduit. 5. In an apparatus of the type indicated, an

annularcasing having a ,series of openings at its periphery for supplying air to the interior thereof, a` ring closure rotatable on the casing to open or close the series of yopenings in the latterand having gear-teeth thereon, a conduit at the periphery of the casing for supplying a mixed charge of fuel and air to thecasing,a valve in; said conduit, and a gear meshing with the teeth on the ring and connected to the valve in the conduit, said gear being operable to open the valve in the conduit andv turn the ring-closure to close the series of openings in the casing, or vice versa. i

6v. A burner for liquid and powdered fuels comprisinga casing having separate throats with intake openings for'supplying prlmaryvand secondary air to support combustion, means for supplying liquid fuel to one of the throats, a conduit for supplying a mixed charge of powdered fuel and air to saidthroat, and means for simultaneously Aclosing the intake opening in vsaid cas ingvfor supplying primary air and opening the conduit for supplyinga mixed fuel charge to said throaty and vice versa. I

7. A burner for liquid and powdered fuels comprising a casing having its interior divided into a plurality-of concentric annular throats with separate intake openings at its peripheryV -for each throat, dampers in each thro-at for controlling the intake openings, means for supplying liquid kfuel to the inner throat, a chamber surrounding the intake opening to lsaid vinner throat and having -openings for supplying air, a conduit for supplying a mixed chargeof powdered fuel and airto said inner throat, and

means vfor vcontrolling the air and mixed fuelr supplying liquid fuel to one of the throats, an annular chamber surrounding said last-named throat and having cooperatingY inlets for adr mitting air and supplying aI mixed charge of powdered fuel and air, and vvalve-meansfor simultaneously closing one of the cooperating inletsl and opening the other inlet. f

9. A burner for, liquid and powdered fuels comprising a casing having its interior divided into a plurality of concentric annular throats with separateintakeopenings for each throat, a

comprisingY a casing having separate throats for supplying primary and secondary air to the casing, vdampers in each throat for controlling the amount of air supplied to the casing, means for supplying liquid f uel to one of the throats, an

annular casing section surrounding said last-V named throat and having separate inlets for admitting air and supplying a mixed charge of, pow,- dered fuel and air to the throat, a damper for closing the inlet in the casing section for supplying air, a conduit for supplying the mixed charge of powdered fuel and air to the other inlet in the casing section, a valve in said conduit, and means for simultaneously operating the damper for the inlet supplyingA air and the valve in the conduit whereby to openlone and'close the other.

ERNEST L'. WO'OLLEY.v

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