US2773460A - Tilting burner mechanism - Google Patents

Description

Dec. 11, 1956 K. s. SVENDSEN 2,773,460

TILTING- BURNER MECHANISM Fil ed March 11, 1953 I If.

Fig. 4.

'1 k INVENTOR Konrad S. Svendsen United States Patent 1 2,773,460 TILTING BURNER MECHANISM Konrad S. Svendsen, Bellerose, N. Y., assignor to Combustion Engineering, Inc., a corporation of Delaware Application March 11, 1953, Serial N 0. 341,693 6 Claims. (Cl. 110-28) This invention relates to fuel burners and more particularly to tiltable burners for directing fuel into a furnace at adjustable angles.

The invention provides a tiltable burner particularly well adapted for pulverized coal firing and which controls within limits the direction at which fuel together with the air for supporting combustion of the fuel is directed into a furnace. The burner includes a fuel conveying conduit concentrically positioned within a secondary air conveying conduit which is mounted on a furnace. The outlet end of the fuel conduit is disposed in a plane inclined at a predetermined angle to its axis and connected to this outlet end is a fuel directing tip constructed of a short conduit of the same diameter as the fuel conveying conduit and havingits inlet end positioned in a similarly inclined plane and in engagement with the outlet end of the fuel conveying conduit. These two conduits are joined together in a manner so that they may rotate relative to one another but may not move relative to one another in an axial direction. Suitable means, including a differential gear drive, are provided for simultaneously rotating the two conduits in opposite directions and equal angular increments which results in tilting the fuel directing tip in a single plane between predetermined extreme angular positions.

It is the general object of this invention to provide a tiltable burner for directing fuel and air into a furnace at adjustable angles and which is relatively simple in construction yet highly satisfactory in operation.

Other and further objects of the invention will become apparent to those skilled in the art as the description proceeds.

With the aforementioned objects in view the invention comprises an arrangement, construction and combination of the elements of the burner in such a manner as to attain the results desired as hereafter more particularly setforth in the following detailed description of an illustrative embodiment; said embodiment being shown by the accompanying drawings wherein:

Figure 1 is a horizontal sectional view through the.

corner of a water walled furnace equipped with an illustrative and preferred embodiment of the tiltable burner of this invention.

Figure 2 is a side view of the burner taken from line 22 of Fig. 1.

Figure 3 is a view similar to that of Fig. 2 but showing the burner tip in its two extreme positions of tilting movement.

Figure 4 is a sectional view taken on line 4-4 of Fig. 1.

Referring now to the drawing, wherein like reference characters are used throughout to designate like elements, reference numerals and 12 designate two Walls of a furnace the inner surfaces of which are provided with longitudinally extending steam generating tubes 14 and at the junction of which is mounted the novel burner of this invention. As illustratively disclosed this burner is adapted to vary the direction at which the fuel and air are projected into the furnace of a steam generator relative to the longitudinal axis of the furnace'for the purpose of controlling super-heated steam temperature of the steam generator in a well known manner. However, it is to be understood that the burner may equally well be employed to vary the direction of fuel projection in other manners and for other purposes.

The burner comprises a secondary air conduit 16 Patented Dec. 11, 1956 through which combustion supporting air flows in the direction indicated by the arrows and within which is positioned fuel conveying cylindrical conduit 18 through which fuel is conveyed and introduced in the furnace as also indicated by the arrows. The inlet of conduit 18 is journaled in a suitable housing member 20 and the outlet is positioned in a plane inclined at a predetermined angle to the axis of conduit 18 as for example, degrees, and is provided with flange 22.

To the outlet end of conduit 18 is rotatably secured tip member 19 which as illustratively disclosed comprises a short cylindrical conduit 24 of the same diameter as conduit 18 and provided with axially extending air directing vanes 23 projecting radially outwardly from its outer surface. The inlet end of conduit 24 is disposed in a plane inclined to the axis of the conduit by an amount equal to the inclination of the outlet end of conduit 18 with respect to its axis and is provided with L-shaped flange 26 which is in sliding contact with and telescoped over flange 22 of conduit 18.

Since the outlet end of conduit 18 and the inlet end of conduit 24 are inclined to the axis of their respective conduits and since these conduits are preferably cylindrical these ends would normally be elliptical rather than circular which would result in a slightly uneven juncture of the two conduits during certain positions of their relative rotative movement. Although this unevenness is slight for the diameter of conduit employed for fuel burners and if desired may be neglected it is preferably eliminated by building up the inner walls of the conduits at these ends, as indicated in Fig. 1, so that the inner edge of the ends form a circle. If desired this unevenness can also be eliminated by deforming the conduits adjacent these ends sufficiently to change the elliptical configuration to a circular configuration. In order for conduits 18 and 24 to be in proper alignment and to rotate relative to one another flanges 22 and 26 are circular. Conduits 24 and 18 are thus joined in a manner so that conduit 24 forms a smooth and uninterrupted continuation of the inner surface of conduit 18 and in order to retain these conduits in this relation flanges 26 and 22 are embraced between the legs of circumferentially spaced U-shaped clamp members 28 which are secured as by cap screws 30 to flange member 26.

Through this arrangement a substantially fluid tight joint is provided between conduits 24 and 18 which permits relative rotation between the two conduits while preventing relative axial movement.

In the preferred embodiment disclosed relative rotation between conduits 24 and 18 is effected through a differential gear mechanism which comprises axially spaced ring or arcuate gears 32 and 34 between which is positioned drive gear 36 in driving engagement with each of the ring gears. .Gear 36 is provided with shaft 40 which is received within openings formed in brackets 38. Operation of the differential gear mechanism is had through pinion 42 secured to shaft 40 and rack 43 or the like, in engagement with pinion 42.

Rotatably positioned over conduit 18 is sleeve 44 which has ring gear 32 secured to its upstream end and which is prevented from moving axially of conduit 18 by the combination of the differential gear mechanism and flange member 46 extending radially from conduit 18. The downstream end of sleeve 44 is provided with radially extending guide members 48 which are circumferentially spaced and suitably bored to slidably receive the shanks of hooks 50 which are hooked into suitable eyes formed on clamps 28. Through this arrangement sleeve 44 and conduit 24 are interconnected so as to rotate in unison. Ring gear 34 is secured to conduit 18 whereby upon rotation of drive gear 36 conduit 18 is rotated in one direction while conduit 24 is rotated an equal amount in the lee opposite direction with. relative axial movement. between clamps 28 and their associated guide members 48 being accommodated by the sliding connection between the guide members and hooks 50. In order to brace the outlet end of fuel conduit 18 within secondary air duct 16 support ring 52 is positioned over sleeve 44 in rotatable relation therewith and is secured to duct 16 by circumferentially spaced radial studs 54.

It will thus be apparent, in operation of the illustrative and preferred embodiment, when it is desired to vary the angle at which fuel flowing through conduit 18 and air flowing through conduit 16 are introduced into a furnace, conduits 24 and 18 are rotated in opposite directions and equal angular increments by means of the differential gear mechanism and its associated structure. Since the angular disposition of the inlet end of conduit 24 is equal to that of the outlet end of conduit 18 this relative rotation causes conduit 24 to tilt in a single plane with the extreme tilting movement above and below the axis of conduit 18 being equal to twice the angular disposition of these ends as shown by Fig. 3 wherein the solid line representation indicates one extreme and the dotted line representation the other extreme;

By initially arranging the burner so that the juncture of conduit 24 and conduit 18 lies in a plane extending longitudinally of the furnace in parallel relation with tubes 14 when conduits 24 and 18 are in axial alignment, as disclosed in Figs. 1 and 2, the tilt of conduit 18 will be longitudinally of the furnace thereby varying the horizontal angle at which the fuel and combustion supporting air is projected into the furnace. However, the disposition of the plane in which the tilting movement takes place is a matter of choice and may be varied as desired by rotating conduits 24 and 18 in unison to any desired initial position.

With this invention a tiltable burner is thus provided which is of uniform cross section, which is reasonably fluid tight at the juncture of the fuel conveying conduit and the fuel directing conduit and which presents no obstruction to the flow of fuel through these elements thus-eliminating unequal coal distribution within the burner caused by a change in cross section from round to rectangular found in prior art designs and also eliminates coking at the burner due to leakage and eddy currents at the juncture of the tip member and the fuel conveying conduit.

While I have illustrated and described a preferred embodiment of my tiltable burner it is to be understood that such is merely illustrative and not restrictive and that variations and modifications may be made therein without departing from the spirit and scope of the invention. I therefore do not wish to be limited to the precise details set forth but desire to avail myself of such changes and alterations as fall within the purview of my invention.

What I claim is:

l. A tiltable burner comprising a straight conduit having a terminus disposed in a. plane inclined at a predetermined angle to the axis of the conduit, tip means comprising a relatively short straight conduit member having an end disposed in a plane inclined at a. similar angle to its axis, means joining said terminus of the first mentioned conduit and said end of the relatively short conduit so that said terminus and said end are juxtaposed to one another and said short conduit forms an extension of the first named conduit, said joining means substantially preventing relative axial movement between said terminus and said end while permitting relative rotary movement therebetwccn, and means including common drive mechanism operative to simultaneously rotate said conduits in opposite directions and equal angular increments.

2. A tiltable burner as defined in claim 1 including a duct for air surrounding and extending axially of the first mentioned conduit and spaced therefrom, and directing vanes extending radially outward from the outer surface of the relatively short conduit and axially of said short conduit for directing the air flowing through said duct in accordance with the angular disposition of said short conduit.

3. A tiltable burner as defined in claim 1 wherein the means for simultaneously rotating the two conduits in opposite direction includes a sleeve member rotatably mounted on the first named conduit but prevented from moving axially thereof, a plurality of circumferentially spaced means interconnecting said sleeve and the relatively short conduit member with this last named means preventing relative rotation between these members and with the connection of this last named means with one of these members providing for relative movement between said means and member in a direction axially of the sleeve, and means operative to simultaneously rotate said sleeve and the first named conduit in opposite directions and equal angular increments.

4. A tiltable burner as defined in claim 3 wherein the means for simultaneously rotating the sleeve and the first named conduit in opposite directions comprises a differential gear mechanism including two identical sector gear means, said gear means being axially spaced with one secured to said sleeve and the other secured to the first named conduit, and a drive gear disposed between said two gear means in driving engagement therewith.

5. A tiltable burner for pulverized coal or the like comprising a straight cylindrical conduit having a flanged terminus disposed in a plane inclined with respect to the axis of the conduit at a predetermined angle, tip means including another straight cylindrical conduit having a flanged end disposed in a plane inclined at a similar angle to its axis, said flanged ends being of substantially equal cross section, means interconnecting the flanged ends of said conduits so that said flanges overlie one another and so that the second named conduit forms a generally smooth continuation of the first named conduit with one of said flanges being L-shaped and telescoped over the other flange, said last named means preventing relative axial movement of the conduits while permitting relative rotary movement, means including common drive mechanism effective to simultaneously rotate said conduits in opposite directions and equal angular increments.

6. In an organization of the type described a duct through which combustion supporting air flows in a predetermined direction, a conduit positioned within said duct and spaced therefrom and through which pulverized fuel is adapted to flow in said predetermined direction, the downstream end of said conduit having a flanged circular terminus disposed in a plane inclined at a predetermined angle to the axis of the conduit, tip means associated with said end of the conduit, said tip means comprising a conduit having a flanged circular inlet end disposed in a plane inclined at a similar angle to its axis, said flanged inlet end being complementary to said flanged outlet end with the circular flanges overlying each other, means securing said flanges together in a manner so as to prevent relative axial movement therebetween while permitting relative rotary movement about the axis of the first named conduit, a plurality of air directing vanes extending radially outward from the surface of the second named conduit and axially thereof for directing the air ,flow through said duct in accordance with the angular disposition of said tip means, and means effective to simultaneously rotate said conduits in opposite directions and equal angular increments.

References Cited in the file of this patent UNITED STATES PATENTS 513,167 Woodhouse Jan. 23, 1894 963,583 Kennel July 5, 1910 1,142,459 Reese June 8, 1915 2,363,875 Kreisinger et a1 Nov. 28, 1944

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