US2126853A

US2126853A - Liquid fuel burner

Info

Publication number: US2126853A
Application number: US64733A
Authority: US
Inventors: Ernest L Woolley
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-02-19
Filing date: 1936-02-19
Publication date: 1938-08-16
Anticipated expiration: 1955-08-16

Description

Aug. 16, 1938. v l E. l.. wooLLEY 2,126,853

LIQUID FUEL BURNER Filed Feb. 19, 1936 4 Sheets-Sheet 2 Aug. 16, 19387. E. l.. wooLLEY LIQUID FUEL BURNER Filed Feb. 19, 1936 4 Sheets-Sheet 5 E. L. WOOLLEY LIQUID FUEL BURNER Aug. 16, 1938.

Filed Feb. 19, 1936 4 Sheets-Sheet 4 .ferai/day /7 Patented Aug. 16, 1938 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to liquid-fuel burners adapted for use with steam boiler or other furnaces and consists in improvements in the means for regulating and controlling the volume of air supplied to the iiame.

One object of the invention is to provide an improved air-register for supplying a maximum amount of air when the burner is operating at maximum capacity and a reduced amount of air in proportion to the reduction in oil ieed and the size of the name.

Another object of the invention is to provide for regulating the amount of air supplied through the register in such manner as to utilize the maximum available draft while maintaining a more uniform velocity of revolution oi the air between the center and the edge of the flame.

Another object of the invention is to provide an adjustable air-register adapted to supply the minimum necessary quantityof oxygen for complete combustion of the fuel with any desired size of ame.

Another object of the invention is to provide an air-register having a plurality of concentric annular throats adapted to be used either separately or conjointly for supplying air to the name as required.

Another object of the invention is to provide an air-register having a plurality of concentric throats with separate vanes or dampers for admitting the air therethrough and means for opening and closing the vanes progressively in sequence to regulate the air admitted through each or all of the throats.

Another object of the invention is to provide manually-operable means for actuating the vanes to control the air supply in proper ratio to the amount of feed of the fuel and the size of the ame.

Another object of the invention is to provide a self-contained compact register oi the type indicated having its control-mechanism of simple structure and proof against derangement or getting out of order, while being adapted for manual operation without special skill or expertness on the part of the operator.

Further objects of the invention are set forth in the following specication which describes a preferred form of construction of the device, by way of example, as illustrated by the accompanying drawings. In the drawings:

Fig. l is a vertical sectional view through a conventional type of boiler front showing an oil-burner applied to the opening therein and embodying the present improved air-register for (Cl. 15S-1.5)

regulating and controlling the amount of air supplied to the flame;

Fig. 2 is an end view of the apparatus shown in Fig. 1;

Fig. 3 is a composite perspective view showing the vanes for the circular dampers at the front of the register and illustrating the relative posi-r tion of the means for operating the vanes;

Fig. 4 is a detailed sectional view on line 4 4 of Fig. 2 showing the arrangement of the damper-operating ring;

Fig. 5 is a detailed sectional View on line 5*-.5 of Fig. 2 showing the construction of the manually-operative means for regulating the dampers;

Fig. 6 is an end view of the register, part sectional on line 6 6 of Fig. 1, showing the vanes for the primary damper in closed position and illustrating their operating connections;

Fig. '7 is a similar view showing the primary vanes in open position.

Fig. 8 is a part-sectional View on line 8-8 of Fig. l showing the secondary vanes in closed position;

Fig. 9 is a similar View showing the damperoperating means and the secondary vanes moved to a position at the start of opening these vanes; and

Fig. 10 is a similar view showing the secondary vanes in full open position.

The present improved air-register is herein shown and described in connection with an oilburner of the pressure-atomizing type as used with natural draft, but it is to be understood that the improvement is adapted for use with burners of other types, for example, those using forced draft. The invention in general consists in providing an air-register having two or more concentric annular throats each having an independent damper or shutter for controlling the ingress of air thereto, and means for operating the different dampers progressively in sequence to regulate the amount of air supplied to the name in accordance with the size of the latter.

Referring to Fig. 1 of the drawings, 2 designates the masonry of the front wall of the boiler furnace which is covered by an outer shell or front plate 3. The present improved air-register is preferably embodied in a unitary structure adapted to be attached to the front of the boiler furnace and serving as the means for supporting the fuel feed-pipe and the'burner at its end, and also the controls therefor. As herein shown the burner-support and air-register comprises an annular casing or sleeve 5 of slightly tapered form vadapted to t closely within the opening 6 in the front of the furnace and formed with a radial ange at its outer end. The annular sleeve or member 5 is provided with perforated earsl or lugs 8 on its periphery, see Fig. 2, which receive bolts 9 projecting from the furnaceplate 3 with nuts screwed onto their ends to secure the sleeve fixedly in position. The sleeve 5 forms the outer boundary wall of the larger throat of the air-register and cooperating therewith is a concentric annular casing I6 which forms a second inner throat for the register. The inner annulus III is provided with a. radial flange II at its outer end and the space between this latter flange and the ilange 'I on the annulus 5 serves as the inlet opening for the air which is admitted through the outer throat.

The inner throat annulus IG is supported from a radial flange or ring I4 suspended on bolts I5 screwed into the flange l of the outer throat 5. Between the radial flanges 'I and II are mounted primary and secondary vanes I6 and I 'I which are pivoted on the bolts I5, previously referred to, to adapt them to be operated to open and close the separate entrances to the register through the throats I5 and 5, respectively. The means for operating the vanes I6 and I'I are preferably arranged as hereinafter des-cribed. The inner throat annulus I8 is supported from the radial flange I4 by means of studs I8. The studs I8 are screwed into the flange I I on the annulus I with their reduced ends passing through bosses in the radial flange or ring I4 and secured thereto by nuts I9, see Fig. 1.

A concavo-convex closure-plate 26 of frustoconical form has its rim shouldered to iit snugly around the inner rim of the ring I4, being secured xedly thereto by bolts 2I passing through lugs on the closure-plate and screwed into a thickened portion of the ring. The inner end of the closureplate 2D is formed with an annular sleeve 22. Fitted within the bore of the sleeve 22 is a tube 25 which serves as an additional air-pipe surrounding the burner-pipe 36, to be later described. The closure-plate 20 is formed with a hub or boss 23 through which projects a rod 26 adapted to slide therein and serving to mount a coupling 2'I for connecting the oil-supply pipe 28 with the burnerpipe 36. The parts of the coupling Z'I are `held together by means of a clamp 3I operated by a i hand-screw 32, these elements being of substantially the same structure and arrangement as shown in my prior U. S. Letters Patent No. 1,843,411, dated February 2, 1932. The coupling 2 also comprises a valve 331 controlled by a hand- -wheel 34 for regulating the feed of the fuel through the burner-pipe 36. The tube 25 has an extended portion 24 secured to the coupling member 2 by means of a bolt 29, the arrangement being such that the burner-pipe 35, its surrounding air-pipe 25 and the coupling 2 may be adjusted axially of the air-register by sliding the rod 26 in its bearing in the hub 23. A pin 35 at the end of the rod 26 is adapted to strike against the n hub 23 to limit the forward sliding movement of f the parts.

' of the tube.

not being herein described in detail as it forms no part of the present invention.

Supported on the inner end of the air-tube 25 is a diffuser-plate 40 in the form of a frusto-conical flange having a hub 39 surrounding the 'tube and secured in place thereon by any suitable means as by welding. The diiTuSer-plate 4d is provided with a plurality of radial slits 4I through which the air passing through the inner throat i is diffused as it flows to the flame, indicated by the dash lines designated 42 in Fig. 1; it being understood that the oil fed through the pipe 36 and forced under pressure through the burner-tip 3l is atomized and sprayed outwardly therefrom to undergo combustion in a ame in the shape of a hollow cone having an included angle of approximately ninety degrees.

As before indicated, the primary and secondary vanes I6 and II for the dampers of the inner throat I and outer throat 5, respectively, are pivoted on a plurality of studs or bolts I5 equally spaced around the flanges and I4, the relative position of the vanes being shown diagrammatically in Fig. 3 of the drawings. The vanes I6 and I'I are of arcuate shape conforming to an annular contour of a diameter equal substantially to the outer diameter of the flanges l and I4. The primary vanes I6 are narrower, substantially onehalf the width of the secondary vanes Il, it being understood that the inlet to the secondary throat 5 is required to be much larger than that to the primary or inner throat I. The vanes I5 and I'I have hubs extending clear across their width with the studs I5 passing through bores therein, and between the vanes is a relatively thin separator ring or annulus 43 supported on the studs i5 and forming a continuation of the radial flange I I on the inner throat I0. Through this form of construction an annular slot 44 is provided between the outer edge of the flange I I and the inner edge of the ring 43 for a purpose later explained.

The radial flange or ring I4 is provided with an offset portion I2 forming a circular seat or pocket I3 in which is rotatably mounted a damper-operating ring 46 connected to open and close the vanes I6 and I'I. The ring 46 is held in place in the annular pocket I3 by cleats 4l, see Figs. 3 and 4, let into recesses in the side of the ring I4 and fastened in place by screws 48. The ring 46 has pins 56 projecting laterally or horizontally inward therefrom with their ends passing through the annular opening or slot 44 between the edges of the flange II and ring 43. These pins 56 engage with cam-slots in depending webs or anges 5I and 52 on the primary and secondary vanes I6 and II, respectively, see Figs. 3 and 6 to 10, inclusive.

In the depending webs 5I of each primary vane I6 is a substantially V-shaped cam-slot 53 through which one of the pins 55 of the operating ring 46 passes. The cam-slot 53 has two

branches

54 and 55, the branch 54 being of arcuate shape of the same radius as the slot 44 and so positioned that it will aline therewith when the vanes are in open position as illustrated in Fig. '7 of the drawings. The other branch 55 of the cam-slot will then assume a position extending radially with respect to the axis of the register. The vanes I'I have similar cam-slots 58 in their webs 52, but these have an opposite relationship. Each cam-slot 53 has an arcuate branch 59 which is so positioned as to aline with the slot 44 when the secondary vanes I l are in closed position, as shown in Figsj and 9 of the drawings, and a straight branch 66 which extends radially when the vanes are in closed position. The pins i) on vthe operatingring .45 project through the slot ld and intoV the cam-v slots 58 of the secondaryvanes li', and duefto;y

the opposite relationship of the cam-slots .of the two sets of vanes, when the ring i6 is rst turnedto open the primary vanes` i6 the pins 5@ will slide in the arcuatebranches 59 without any operative effect on the secondaryvanes il. `It will be understood that the operatingring 46 is turned in a clockwise direction to openthe vanes so that initially the pins 5) slide in theradial branches 55 of the cam-slots L53 to swingV the primary vanes shown in Fig. 6, to an open position, .as shown in Fig. 7 At this juncture, if the operating ring 46 is further rotated in the same direction the pins 50 will slide in the arcuate portions 54 of .the

cam-slots 53 to maintain the primary vanes i@ open while at the same time engaging in the radial branches 5i] of the cam-slots 58 of the secondary vanes l? to open these latter vanes; the complete method of operation of the dampervanes being more particularly described herein-` after.

Any suitable means may be provided for manually rotating the operating ring 45 to regulate the position of the vanes of the primary and secondary damper As shown most clearly in Figs. 2 and 5, the ring i5 is provided with rackteeth 5ft on its outer periphery which mesh with the teeth of a pinion S5. The pinion 55 is fast on the end of a shaft or spindle E55 which may be constructed integrally therewith as shown in Fig. 5. The shaft 55 is journaled in a bearing hub 6l on a plate 58 fastened to a projecting portion of the radial ange H3 by meansoi bolts 69, see Fig. 2. A crankwarm lil is keyed to the outer projecting end of the shaft 55 and provided with a handle 'il for turning it and a pointer i2 projecting in the opposite direction. The bearing plate 58 has a circular boss 'irl marked with graduations indicated at l5, see Fig.. 2,.with which the pointer 'l2 is adapted to register as thel crank-handle lo is turned to rotate the ring 5.15; whereby to indicate the position of the dampers to the operator at the front of the furnace. A handnut i3 screwed onto the threaded end of the shaft E5 may be employed to bind the crankhandle 'iii against the boss 'i4 to maintain the adjustment. in the closure-piate Ri is a sightopening l5, shown in Fig. 2, which is normally maintained closed by a cover li pivoted on a bolt 18.

The method of operation of the complete burner is as next explained. Liquid fuel is sup-.

, supplied through the inner throat l, being admitted at the circumference of the air-register at its outer end by opening the primary vanes i5. The vanes l5 are opened by turning the craniahandle 'it in a countercloclrwise directionV to rotate the operating ring l5 in a clockwise direction, as viewed in Fig. 2, through the interengagement of the racleteeth on the ring with the gear-teeth of the pinion 55. Assuming that both the primary vanes l5 and the secondary vanes il are closed, as indicated in Fig. l,

i5 from a closed position, .as

the clockwise rotation of the operating ring 55 will iirst cause the pins 5@ to slide in the straight branches 55 of the cam-slots 53 in the webs 5i, see Fig. 6, to rock the. primary vanes into open position, shown in Fig. 7, as the pins reach thek end of said branches. During this movement of the operating ring die the pins 5@ slide in the arcuate branches 59 of the cam-slots 5e in the webs 52- of the secondary vanes il! without causing any movement of these latter vanes. The primary vanes i5 can thus be opened to any extent in accordance with requirements for admitklv ting air through the inner throat l@ to feed 1t to the flame in proper volume when the latter is reduced in size.

When a greater capacity of the burner is desired the fuel feed is increased by regulating the valve 33 and the secondary vanes are opened to increase therdraft and thereby the flow of air to the flame. The secondary vanes il are opened by continuing to rotate the operating ring it in the same direction as previously described to cause its pins 5l) to ride into the radial branches 55 of the cam-slots 58 in the webs 52 on the vanes il, see Fig. 9; thereby rocking the secondary vanes il to open position as illustrated in Fig. l0. The extent of opening of 'the secondary vanes may be varied in accordance with the size of the-name to control the flow of .air through the outer throat 5. With the vanes open they act as baffles to collect the air circulating in the boiler-room to direct it down into the damper openings at the periphery of the register'. A small amount of air is admitted at the front of the register to be drawn through the pipe 5 to feed directly to the flame adjacent its axis, this being of advantage to avoid overheating the burner-tip. lThe air passing through the inner throat l@ reaches the iiamethrough the slots il in the frusto-conical difiuser-plate di), this element not being essential to the proper operation of the air-register but having advantages as later pointed out.v

By adjusting the damper openings in the airregister through the means of the primary and secondary vanes air is supplied in proportion to the quantity of fuel burned under any particular condition as desired. W'hen the feed is restricted, for aflame of relatively small diameter, the air is supplied through the inner throat only, insuring proper mixture of the oxygen and fuel without excess air and as the feed is increased an additional supply of oxygen is provided through the outer throat 5. Y

In liquid-fuel burners of the present type, in which the flame is produced by pressure atomizing, the flame takes the form of a hollow cone and for proper operating conditions the area of the throat of the air-register supplying oxygen to the llame should be substantially equal in diameter to the outer diameter of the iamc. In other words, the flame cone should extend across the whole extent of the throat through which air is supplied. Further, to preserve the shape of the flame the air should revolve within the register and advance toward the burner-tip spirally, with little velocity longitudinally of the axis of the burner but with a high velocity of rotation. If this effect is not secured and the air permitted to rush toward the burner-tip along the axis of the burner the flame will be depressed by the force of entering air and the requisite conditions for efcient mixture of oxygen with the fuel cannot be obtained.

In all types of air-registers previously used the entering air revolves as a mass with a maximum velocity at the periphery of the throat and the velocities of other strata reduced in proportion to their distance from the axial center of the throat. Since the pressure at the outer periphery cannot be greater than the force which produces it, that is the draft within the furnace, it would follow that the draft at the outer periphery of the throat of the register is substantially the same as the draft in the furnace; but the draft at each stratum from the outer periphery toward the center or axis of the register is less than the draft in the furnace, reaching a minimum value at the center of the register.

Since the air velocities obtained vary as the radius from the axis, the mean velocity will be at a point midway between the axis and the periphery of the throat and it will therefore be seen that the maximum available draft pressure drop over the full extent of the register is not utilized so that the capacity of the register is thereby restricted. However, under normal conditions the pressures tend to equalize with the result that the air supply in the low negative pressure area rushes toward the high negative pressure in the furnace and the effect of this is to break down the shape of the flame and produce a pulsating motion in the air supply as this condition is alternately built up and then dissipated through equalization.

The use of an air diffuser of considerable diameter immediately behind the burner-tip tends to ameliorate this condition by segregating the lowest negative pressure areas from the rest of the register throat so that to a certain degree conditions are stabilized. However, the use of a large diffuser materially reduces the area available for air supply.

Due to the present improved constructionrof the register with the outer and inner throats having separate regulating dampers the air pressure and velocity differentials across the inner register throat are materially improved. As the air is supplied through three separate channels, the outer throat 5, inner throat il] and axial air-pipe 25, the full draft differential will be available in each channel. In the outer throat 5 theair velocity will be a maximum at the outer periphery of this throat and a minimum at its inner periphery so that the average air velocity will be at the mean of the radii of the walls of this throat and the pressure differential across this annulus will be limited to the difference between maximum and minimum velocities transposed in terms of pressure.

Likewise, in the inner throat Il the same maximum velocity as realized in the outer throat will be available, this velocity being a maximum at the outer periphery of the inner throat and a minimum at the periphery of the diffuser-plate 4G, with the air pressure differentials being limited to the annulus in question.

The additional air supplied through the axial pipe or tube 25 surrounding the feed-pipe 3B is under the full draft differential, but as the area of this annulus is small it is not required to regulate the supply therethrough. The air admitted at this point tends to stabilize the air condition on the inner or furnace side of the diffuser and, as before stated, is useful in preventing overheating of the burner-tip.

Since the areas of pressure diiferential across the register throat are materially reduced by dividing the throat into a plurality of separate annuli a smaller diameter of diffuser-plate can be used, thereby increasing the effective area of the register throat as a whole and providing increased air capacity. Moreover, since the average air velocity across the full throat is much higher in the present improved form of construction than in previously used air-registers the air capacity of the register as a whole is materially increased. Further, since the areas of pressure diierential have been reduced and the pressure differentials largely diminished, the air supply is free from pulsations, allowing a more accurate regulation of the supply and insuring maximum efficiency in combustion.

The present invention constitutes an important improvement in the art by providing conveniently-operated means for controlling the air supply to the flame in proportion to its size; reducing the pressure differentials in the air supply at the flame; and preventing fluctuations or pulsations in the air current as it meets the flame.

By the use of the present improved air-register the ultimate emciency in burning liquid fuel is secured by thoroughly oxygenating the fuel particles while supplying the minimum necessary quantity of air for complete combustion.. Thus, any excess of air which would dilute the products of combustion and diminish the temperature is avoided, While a most intimate contact is secured between the fuel particles and the oxygen. From these advantageous results it is obvious that the invention provides for the utmost economy in fuel during all stages of operation of the burner.

While the present improved air-register is herein shown and described as embodied in a preferred form of construction it is to be understood that various modifications may be made, in the size, shape and arrangement of its parts without departing from the spirit or scope of the invention. Therefore, without limiting myself in this respect, I claim:

l. An air-register for liquid-fuel burners comprising an annular casing, inner annular walls dividing the casing into a plurality of separate throats, a damper for each throat comprising a plurality of vanes, and a common means for operating the vanes of the separate dampers to open or close the different throats in a predetermined sequence.

2. An air-register for liquid-fuel burners comprising a casing having its interior divided into a plurality of separate throats, dampers for the different throats, and means for operating the dampers in sequence to progressively open or close the throats to the ingress of air.

3. An air-register for liquid-fuel burners comprising a casing, inner walls in the casing dividing its interior into a plurality of separate throats having intake openings at the periphery of the casing, dampers in said openings, and means operative to open first one damper and then another in sequence.

4. An air-register for liquid-fuel burners comprising a casing having its interior divided into a plurality of throats with a separate intake opening for each throat, a damper for each' throat, and a rotary member connected to open or close the dampers progressively in sequence.

5. The combination of a casing, partitions dividing said casing into a plurality of annular throats having separate intake openings, a damper in the intake opening of each throat and each damper comprising a plurality of vanes, and

means connected to all the vanes and operable to open or close the vanes of first one damper and' then another.

6. An air-register comprising a casing having its interior divided into a plurality of throats with separate intake openings, separate dampers in the openings and each damper comprising a plurality of vanes, a rotary operating ring, and cams operated from said ring to open the vanes of first one damper and then another.

'7. An air-register comprising a casing having its interior divided into a plurality of annular throats with a separate intake opening for each throat, separate dampers for the intake openings and each damper comprising pivoted vanes formed with cam-surfaces, and a rotary operating ring having means engaging the cam-surfaces to open or close the vanes of the different dampers.

8. An air-register for liquid-fuel burners comprising a casing having its interior divided into a plurality of throats, said casing having sepa rate intake openings at its periphery communicating with the different throats, a plurality of pivoted vanes in each intake opening having depending webs formed with cam-slots,an operating ring rotatably mounted on the casing, and pins projecting from the operating ring through the cam-slots in thewebs ofthe vanes and operative to open or close the vanes when the ring is rotated in opposite directions.

9. A liquid-fuel burner structure comprising a central feed-pipe, a burner-tip at one end of the feed-pipe, a central air-tube surrounding the burner-tip, a casing surrounding the burner-tip and having its interior divided into a plurality of annular throats, said casing having separate intake openings at its periphery communicating with the diierent throats, a damper for each intake opening comprising a plurality of vanes, a rotary member, and means operative from said rotary member to open rst the damper for an inner throat and then the damper for an outer throat.

10. An oil-burner structure comprising a central feed-pipe, a burner-tip at one end of said pipe, an air-tube surrounding the pipe and open at its opposite ends, a diffuser-plate at the end of the air-tube located adjacent the burner-tip and provided with a plurality of apertures, a casing surrounding the burner and air-tube, a partition within the casing dividing its interior into inner and outer throats, said casing having intake openings at its periphery leading into the dierent throats, a closure-plate at the outer end of the casing, dampers in the intake openings each comprising a plurality of vanes, a ring mounted for rotation on the closure-plate, and

means operative from the ring to open the vanes of the damper for the inner throat and subsequently the vanes of the damper for the outer throat during the continued rotary motion of the ring.

l1. An air-register comprising an annular casing, an annular wall disposed within the casing to divide it into a plurality of separate throats, a radial flange on said inner wall forming an intake passage to the outer throat, a closure-plate spaced outwardly from said radial ange and forming an intake passage to the inner throat, a plurality of pivoted vanes for closing the intake passages to the ydifferent throats, webs on said vanes formed with cam-slots each comprising an arcuate branch and a radial branch, a ring mounted for rotation about the closure-plate, and pins projecting laterally from said ring through the cam-slots in the webs of the vanes.

12. An air-register for liquid-fuel burners cornprising a substantially cylindrical casing, a Wall dividing the interior of the casing into a plurality of annular throats, said casing having a plurality of intake openings in its outer periphery arranged in axially-spaced relationship and communicating with the diierent throats, a separate damper for each intake opening, and a common means for operating the separate dampers to open or close the separate intake openings in a predetermined sequence.

13. An air-register for liquid-fuel burners comprising a substantially cylindrical casing, cylindrical walls dividing the interior of the casing into a plurality of separate throats, a radial partition extending between one of the cylindrical Walls and the periphery of the casing to form separate air passages to the throats, said casing being provided with separate intake openings at the circumference thereof and at opposite sides of the partition, and a damper in each opening for regulating the ingress of air through the register.

14. An air-register for liquid-fuel burners comprising an annular casing, cylindrical walls within the casing, one of said Walls having a radial ange at one end extending outwardly to the periphery of the casing intermediate the ends of the latter, a closure for closing the outer end of the casing, said inner walls and closure forming a plurality of separate throats, said casing having a plurality of intake openings at its outer periphery on opposite sides of the radial flange communicating with the different throats, dampers for said intake openings, and means for operating the dampers.

ERNEST L. WOOLLEY.