US2627307A - Concentric gas and air burner - Google Patents

Description

Feb. 3, 1953 Filed July 24, 1950 c. J. WESTLING CONCENTRIC GAS AND AIR BURNER 5 Sheets-Sheet l INVENTOR CARL J. WESTLlNG 5 Sheets-Sheet 2 ....|-J.|'.ZT.'Z.ZZZ

INVENTOR CARL J. WESTLING C. J. WESTLI NG CONCENTRIC GAS AND AIR BURNER FIG. 2.

Feb. 3, 1953 Filed July 24, 1950 Feb. 3, 1953 c. J. WESTLING CONCENTRIC GAS AND AIR BURNER 5 Sheets-Sheet 3 Filed July 24, 1950 INVENTOR WESTLING MQE 2 ZI'TO lZI J EYS c. J. WESTLING CONCENTRIC GAS AND AIR BURNER Feb. 3, 1953 Filed July 24, 1950 5 Sheets-Sheet 5 INVENTOR CARL J. WESTLING BY 7 41W fl%%fim A dRNEYs F IG. 8.

Patented Feb. 3, 1953 CONCENTRIC GAS AND AIR BURNER Carl J. Westling, West Orange, N. J assignor to H. A. Brassert & Company, New York, N. Y., a corporation of Illinois Application July 24, 1950, Serial No. 175,579

This invention relates to gas burners, and has particular reference to burners for burning gas under pressure for the purpose of heating regenerators, stoves, checkerwork, and heat exchangers and preheaters generally, although the invention is not limited to that use.

Gas burners of the aforementioned general type usually are arranged horizontally, and their nozzles must be disengagedly connected with a corresponding opening in the stove in order that the burners may be relatively easily disconnected and replaced for repair and maintenance purposes. Such burners operate by aspirating a proportional amount of air for intermixture with the gas stream to form the combustible mixture as in the older type of burner. In the case of more modern burners, an air blast is controlled by metering type regulators to maintain a correct ratio of air to gas flow from which. the primary impulse is obtained. The gas-air mixture generally has been ignited by the incandescent combustion chamber walls at the start of the burner operation. In order to secure efficiency, modern pressure burners are used with which pressure is created just beyond the nozzle of the burner and, unless the joint between the nozzle and the stove is tight, gas and flame leaks or stings out through the disconnectable joint so that a dangerous carbon monoxide gas or flame hazard for the operators is created. Arrangements to make the joint tight generally impair the facility of disconnection required when changing the regenerator stove from the firing to the blast portion of the cycle or vice versa.

In accordance with the present invention, a

pressure gas burner for heating blast :furnace stoves, regenerators and the like is provided, in which the area at the nozzle outlet is under positive pressure substantially at all times instead of suction, thereby precluding entry of atmospheric air, and in which the burner is sealed to the stove in such a way that outward leakage of gas or flame is precluded and coupling and uncoupling of the burner to and from the stove are facilitated, thu enabling ready and rapid inspection, repair and replacement.

In a preferred embodiment of the invention, the tubular burner is horizontally mounted on a radial track rail on which the burner is advanced retracted by a simple arrangement, including swivel supply connection for coupling and uncoupling the burner to and from the stove, and the burner nozzle is provided with a gasket which engages seals the joint between the nozzle and the stove under suiilcient pressure toimaintain a tight joint to prevent outward leakage,

11 Claims. (Cl. 158-109) notwithstanding the differential pressure at the burner nozzle and the atmosphere. Mounted Within the tubular housing of the burner is a burner casing having a pilot burner or refractory cone positioned in the axial center of the nozzle and encircled by an annular ring of vanes inclined from the periphery at an angle so that the vanes impart a generally spiral flow to the gas, which is supplied under pressure to the annular space between the burner casing and the tubular housing.

The annular gas space between the burner casing and the tubular housing is separated from, the outer end of the housing by a diagonal partition and a centrifugal fan driven by an electric motor is mounted axially within the housing for drawing atmospheric air through a damper and forcing it axially through the burner casing between the annular-1y arranged inclined vanes to impart a spiral flow and to mix with the gas stream beyond the burner nozzle for combustion within the stove.

The annulus type of orifice provides a means to accurately measure the volume of air flow through the burner without the necessity of having a long straight length of pipe as is required for a conventional orifice plate and is characterized by a very stable impulse and the magnitude of the difference in pressure for any given flow rate may be varied by adjusting the width of the annular opening.

The arrangement of the centrifugal fan is such as to produce the effect of an axial flow blower, but with less critical clearance requirements between impeller' and easing than is required in axial blowers to maintain efliciency. The damper comprises a slotted cone-shaped disc rotated axially of the burner relatively to a complementary slotted conical plate, the rotation being effected by an automatic control regulated by use of metering orifices on gas and air so as to provide the proper fuel-air mixture for efiicient combus tion.

The pilot burner may be separately supplied with fuel and maintains constant and immediate i nition of the gas and air mixture at the nozzleof the burner and within the stove. Gas to the pilot burner may be supplied from the annular gas passage of the burner when the gas is sufiiciently clean to prevent fouling of the relatively small pilot burner gas ports. The burner is a refractory case or ring having a center burner tunnel in which the gas-air mixture burns to provide an incandescent surface at the end of the burner block, thereby insuring the constant and immediate ignition of the combustible mixture.

It will be seen that the pressure gas burner of this invention provides a highly efiicient means for effecting complete combustion Within the stove and at the same time, is compact and selfcontained by reason of its construction and may be readily disconnected from and connected to the stove by the novel mounting and coupling mechanism described. I:

For a more complete understanding of the invention, reference may be had to the accompanying drawings, in'whioh:

Figure 1 is a side elevation of the gas burner of this invention, shown coupled to a stove, as seen along theline Il of Fig. 2;

Fig. 2 is a rear elevation, as seen along the line 22 of Fig. 1;

Fig. 3 is a plan view of the stove, showing it in various uncoupled positions as seen along the line 33 of Fig. 1;

Fig. 4 is an axial section through the burner as seen along-the line 4--4 of Fig. 3;

4.-A is an axial section of a solid burner nose'block;

' Fig. 5 is an axial view of the nozzle of the burner as seen along the line 5- 5 of Fig. 4;

. Fig. 6'illustrates the construction and'arrangement of the vanes of the mixing nozzle as seen along the line i-6 of Fig. 5; g

- Fig. '7 is a transverse section through the outer end of the air intake of the burner as seen along the line 'l'I-'of Fig. 4; and

Fig-8 is a fragmentary section through the outer end of the burner showing a modification of the air metering damper.

-Referring to the drawings, numeral Ii] designates the casing of a conventional stove having the hot blast main l I, both connected to the horizontal burner duct 2 with whose flange 43 the nozzle of the burner Id of this invention is adapted. to be connected.

The burner M includes a cylindrical housing IE- having the gas pipe extension IE onits lower side provided with a flange ll which forms part of a swivel is by which the burner is rotatably but gas-tightly connected to the elbow duct l9.in turn connected by second swivel 29 to the gas main .2 I. i The lower flange [8' of swivel I8 and elbow duct is are supported on a frame 59' having rollers 22 resting on a curved rail 23 whose center of curvature is the center of the swivel 2i], i. e., the center of gas main 2|. provided witha handwheel 22 whereby the entire burner- Ili may be bodily swung toward and away from abutting connection with the stove duct l2, to the-jlimit of rail stop 23.- Further turning of the burner proper for more ready access forclean-out purposes may be effected about swivel [.8 by rotating handwheel 24 and connected sprocket 24' meshing witha chain 25' whose opposite ends are fixed to the opposite sides of the lower flange [8 of the swivel 58, as shown in 'Figs. 1 and 3;

V the inner end of the burner housing l5 and a clamping ring 2?" so as to project slightly beyond the inner or nozzle end of the-stove housing l I, as is shown in Fig. 4. Accordingly, by rotating hand- One of the rollers 22 is wheel 22' until the gasket 2? abuts the stove duct flange i3 and then drawing bolts 26 tightly, the joint between the burner l4 and the stove H! is sealed. Conversely, when bolts 25 are disengaged from the burner I4 and the handwheel 22 is rotated in the opposite direction, the burner it rolls-back over rails 23 to the rail stop 23' and the burner I4 is readily disconnected from the stove It. Further rotation of the burner may be obtained by rotating handwheel 2 5, its various positions being shown in phantom in Fig. 3.

Referring now to Fig. 4, the housing 55 contains municating with gas pipe it but disconnected y from the interiorof the housing l5 by a diagonal partition 28 welded at its opposite ends to the casing 28 and housing l5. 7

Bolted to the inner end of the casing 25 by bolts30is the burner nozzle 3|, which comprises two eccentric short tubes 32 and 33 of sheet steel. As shownparticularly in Figs. 4, 5 and 6, the outer tube 33. is slotted substantially axially at spaced points and the ears .thus formed are bent backwardly against the upper edge of the inner tube 32 and welded thereto to form the diagonal vanes 34., The, adjacent vanes 3d accordingly form between them the inwardly and tangentially inclined passages or slots 35 which communicate with the plenum chamber 36 within the casing 28.

Mounted Within the inner nozzle tube 32 is the ceramic pilot burner 31 which is provided With'a diverging or tapering central passage 38 terminating in a conical tip which becomes incandescent when the combustible mixture of fuel gas and air is supplied thereto through nozzle plate Behaving jet passages 40 communicating witha space il supplied with gas by pipes 42 from gas main 2| at a point ahead of the main gate'valve V. The lower end of the pilot tube 32 -is closed by the partition 43 carrying the nozzle plate 39, and forming with partition 44 the pilot gas chamber M to which gas pipes 42 are'connected. The pilot burner block 31 maybe made solid as shown in Fig. 4-A, so as to maintain ignition by its incandescence. Block 3'! also .acts as a heat insulating barrier protecting the blower.

Mounted coaxially with the burner housing I5 and the casing 28, and suitably supported on brackets 45 is an electric motor 46 whose shaft carries and drives the bladed wheel 41, which is of a conventional design of centrifugal blower wheel including the peripheral, substantially radial but curved blades 48. A transverse par" tition 49 extends across the housing 15 outwardly from the centrifugal blower t? and has a central opening formed by inwardly turned flange 50 and communicating with the eye of the centrifugal blower 41. V The outer end of the housing [5 is closed by the imperforate plate 51 connected thereto by bolts and spacers 52 so as to provide the lateral air intake opening 53 through which atmospheric air is drawn by blower 47 into cas ing 28 as indicated by the arrows in Fig. 4.

, interposed between the intake opening'53 and the partition 49 is a damper 54 composed of a fixed plate 55 of generally conical cross-section, as shown in Fig. 4, and having the-radial slots 56 shown in Fig. 7. A disc 57 overlies the inner surface of the stationary plate 55 and is provided with corresponding slots 56 which aread-apted to cooperate with slots 56 as the disc 51 is rotated about its axis relatively to the stationary disc 55. Movable disc 51 is provided with a hub 58 secured to a shaft 69 journalled in a tubular extension 60 on the stationary dam-per plate 55. The projecting outer end of shaft 59 is secured to a radial lever 6| which in turn is connected near its outer end by a link 62 to a crank 63 of a conventional form of control mechanism housed within hood 64 and operated by thermocouples within the stove to control the temperature by regulating the damper 54 through the crank 63, link 62, lever BI and relatively movable slotted disc 51.

In Fig. 8 a modified form of damper is shown in which the atmospheric air is admitted through the perforated bottom plate 5| to the relatively movable slotted damper plates 55 and 57 constituting the damper 54 which is actuated in the manner described from the automatic control mechanism in hood 64 through the lever 6|.

Observation of the burner flame may be seen by looking through inspection port 65 sighted between the vanes 34 at the proper angle, as is indicated in Fig. 3.

The burner coupling flange plate l3 mounted on the burner duct I2 preferably is of special construction and is fitted with the horizontal rail 66 on which the circular door 61 is carried on rollers 68 about a vertical pivot 89. The door 61 carries the cross bar 10 having end notches H in which the bolts 26 are adapted to lodge to lock the door 61 in place when the door Bl is centered on rails 66 in registry with the burner duct I2 to close the same after uncoupling the burner.

In operation of the apparatus of this invention, the pilot flame at orifice 38 is lit and the burner l4 coupled to the stove after the door 61 is unlatched and moved along its rail 66 to the position shown in Fig. 2 opening duct 12. The burner coupling operation involves first assuring that the burner I4 is swung by handwheel 24 to the limit of its counterclockwise position about swivel l8, which aligns the burner axis tangent to an are having its center of ourvature at the axis of gas main 2| and swivel 20. Then the burner 14 is rolled on its carriage l9 along track 23 by pushing the same or by rotating handwheel 22' whereby the burner l4, elbow l9 and carriage I9 move about swivel 2i! until the gasket 21 in the nose of the burner 14 abuts the flange l3, as shown in Fig. 4. The bolts 26. are engaged with brackets 26 on the burner and drawn up to airtightly seal the joint between the burner l4 and the stove duct flange I3 as indicated in Figs. 1 and 4.

The air damper orifices 56' are initially adjusted manually by means of handle 6!, shown in Fig. 7, the switch of motor closed to start the motor 46 driving centrifugal blower 41, which forces pressure air through the casing 28 in the manner of an axial flow blower but with the greater volume of a centrifugal blower, because of the arrangement of the partition 49, 5|] and casing 28.

When main gas valve V is opened, gas under pressure enters annular space 29 from gas pipe [6 to flow between the diagonal vanes 34 to mix with the fair also flowing between the vanes 34 from plenum chamber 33 Within the casing 28. The inclination of the vanes 34 is such that a converging spiral flow is imparted to the air-gas mixture, which converges just beyond the pilot orifice 38 to be ignited thereby and burn within the insulated burner duct l2. Proper gas-air mixture is maintained automatically by the mechanism housed within hood 64, which adjusts the rotating slotted damper disc 51 relatively to stationary damper plate by means of crank 63, link 52 and lever 6| to regulate the air entering the burner through slot 53 for best efficiency. a

The orifice 38 through pilot burner block 31 is made diverging and the tip of the block conical, so that the burner tip becomes incandescent to maintain pilot burner ignition for a time in case of short duration failure of pilot gas supply or the like. Inspection of the pilot flame and burner flame may be made through port 65. i

In order to uncouple the burner M from the stove, the gas valve V is closed, the blower 41 is shut off after combustion ceases, and bolts 26 released. The entire burner 14 is rolled back on its tracks 23 to the limit of stop 23, which places it in the normal out position shown in phantom position and designated A in Fig. 3. The door 61 is then rolled along its rails 66 and locked closed over duct 12 by bolts 26.

In the event that the burner I4 is to be inspected or parts are to be replaced or repaired. the burner [4 may be swung at a wider angle, from position A to position B in Fig. 3, by rotating handwheel 24, which pivots the burner I4 on its carriage l9 about swivel l8. It will be observed from Fig. 3 that when the burner l4 stands in position B, it is freely accessible from both ends, and inspection and repair are facilitated.

Although a preferred embodiment of the invention has been illustrated and described herein,

it is to be understood that the invention is not limited thereby, but is susceptible of changes in form and detail within the scope of the appended claims.

I claim:

1. In a gas burner for heating a hot blast stove and the like, the combination of a substantially tubular housing having a nozzle at one end, a support mounting said housing in substantially horizontal position, a power driven fan within said housing for forcing air through said nozzle, a main supplying gas under pressure connected to said nozzle for admixture with the air forced therethrough, a vertical axis swivel in said main, a rail concentric with the axis of said swivel, and rollers on said support and engaging said rail about which said burner may be moved to couple the same to and from said stove.

2. In a gas burner for heating a hot blast stove and the like, the combination of a substantially tubular housing having a nozzle at one end, a

' support mounting said housing in substantially rail about which said burner may be moved to couple the same to and from said stove.

. 3. In a gas burner for heating a hot blast stove and the like,'the combination of a substantially tubular housing having a nozzle at one end, a support mounting said housing in substantially horizontal position and for rotation in a substantially horizontal plane, a power driven fan aeansor within said housing for-forcin air through said nozzle; a main supplying gasunder pressure-connected-tosaid nozzle for'admixture with the air forced therethrough," a vertical axis swivel in said-main, a pipe connecting said swivel to said housing; a second swivel inter-posed between'said pipe andsaidhousing about which said burner housing may be rotated relative to said support and independently of said first swivel, a rail concentric with the axis of said first swivel, rollers on said supportand engaging said rail about which said burner may bemoved to couple thesame to and from said stove.

421111 a-gas burner for heating a hotblast stove and the like, thecombinationot a-substantially tubular housing-having a nozzle atone-end, a

support mounting said housing in substantially horizontal positionand-for rotation in a substantially horizontal plane, a power driven fan within said housing forforcing air throughsaid nozzle, a main supplying gas underpressure connected to 'said' housing for admixture with the airiorced therethrough, a vertical axis swivel in said main, a pipe connecting said swivel to said housing, a second swivel interposed between said 5. In a-gas burner for heating a hot blast stove and the" like, the combination'of a substantially tubular housing having a nozzle at one end, a support mounting said housingin substantially horizontal position, a power-driven fan within said housing for forcing air through said nozzle,

a main supplying gas under pressure connected to said housing for admixture with the air forced therethrough, a vertical axis swivel in said main, a U shaped pipe connecting said swivel to said housing and carried at its free end on said housingsupport, a second vertical axis swivel interposed between the free end of said pipe and said housing about which said housing may be rotated relative to said pipe and said support, a railconcentric with the axis of said first swivel, rollers on said support and engaging said rail about which said burner may be moved to couple the sameto and from said stove, and means for rotating said burner housing about the axis of said second swivel independently of said first swivel and'said support. V

6.- In a gas burner for heating a hot blast stove and'thelike, the combination of a substantially tubular housing having an openin at one end, a support mounting said housing in substantially horizontal position, a tubular casing within said housing and forming an annular space therewith, said casing having a nozzle at one end adjacent to'said opening, a fan within said housing for forcing air through said casing toward said opening, motive means for drivin said fan, a tube concentrically mounted within said nozzle and formingan annular passage therewith, vanes inclined with respect to the axis of said casing and extending" substantially radially between said nozzle and said tube for imparting a spiral motion'to the air, and a source of gas under pressure connected to said annularspaceto supply gas 'for admixture with the air-forced through said nozzle.

' 7. In a gas burner forheating a hot blaststove and the like, thecombination of a'substantial'ly tubular housing having a substantially-circular opening at one end,- asupport mounting said housing in substantially horizontal positioma tubular casing within said-housing and. forming an annular space therebetween, saidcasing hav ing a nozzle at one end adjacent to said:ope ning, a fan within said housing for forcing air through said casing toward said-opening, motive means for driving said :fan, a tube concentrically mounted within said nozzlein spaced relation thereto, vanes inclined with'respect to the axis of said casing extending substantially .radially between said tube and said nozzle, and forming aperturesbetween them communicating with said annular spaceand said casing for imparting a spiral motionto the air, and a source of gas under-pressure connected to said annular space to supply gas for admixture with the air forced through said-nozzle.

8..- In a gas burner for heating a hot blast stove and the like, the combinationof a substantially tubular housing having a substantially circular opening at one end, a support mounting said housing in substantially horizontal position, a tubular casing within said housing and forming an-annular space therebetween, said casing have ing a nozzle at one end within said extension, at

fan within said housing for forcing air through said casing for discharge through said, opening, motive means for driving. said fan adjacent to said casing, a tubular nozzle on said casing adjacent to said opening, a tube concentrically mounted within said nozzle, said nozzle beingslit atperipherally spaced points-and having ears bent inwardly toward said tube to form vanesinclined relative to the :axis'of said tube-and extending substantially radially between said nozzle and said tube for imparting a spiral motion to the air, and a source of gas under pressurelconnected to" said annular space to supply gas for admixture with the air forced through said nozzle.

9. In a gas burner for heating a hot blast stove and the like, the combination" of a substantially tubular housing having a substantially circular opening at one end; a support mountin said housing in substantially horizontal position, a tubular casing within said housing and forming an annular space therewith, said casing having an inner end spaced inwardly of said opening, a nozzle on said inner end of said casing, a fan within said housing for forcing air throughsaid casing for-discharge through said opening, a-motive means for driving said fan, atube concentrically mounted within s-aid'nozzle, fixed vanes extending substantially radially between said nozzleand said concentric tube, said vanes being substantially inclinedwith respectto a plane perpendicular to theaxis of said casing to impart a spiral motion to the air, av pilot burner within said tube adjacent to said opening and asource of 'gas' under pressure connected to saidv pilot burner and to said annular space to supply gas for admixture at the opening with'the'air .forced through the nozzle. 7 a

10. In a gas burner for heating a hotblast stove and the like, the combination of a substantially tubular housing having a discharge opening at one end, a support mounting said housing in substantially horizontal position, a'damper comprising relatively rotatable slotted discs mounted in the opposite end of said housing from said discharge opening, a partition mountd across said housing adjacent to said damper and having an axial air inlet opening, a centrifugal fan mounted within said housing adjacent to said partition and coaxially with the inlet opening, a tubular casing Within said housing extending from said fan substantially to said discharge opening, to convey air from said fan to said discharge opening, said casing having a nozzle thereon adjacent to said discharge opening, motive means for driving said fan, axially diagonal vanes extending substantially radially of and within said nozzle for imparting a spiral motion to the air, and a source of gas under pressure connected t said housing for admixture at said discharge opening with the air forced through said casing.

11. In a gas burner for heating a hot blast stove and the like, the combination of a substantially tubular housing having a discharge opening at one end, a support mounting said housing in substantially horizontal position, a damper comprising relatively rotatable slotted discs mounted in the opposite end of said housing from said nozzle, a partition mounted across said housing adjacent to said damper and having an axial air inlet opening, a centrifugal fan mounted within said housing coaxial with the partition opening and adjacent to said partition, a tubular casing extending from adjacent to said fan substantially to said discharge opening to convey air from said fan to said discharge opening, a nozzle on the end of said casing adjacent to said discharge opening, motive means for driving said fan, substantially parallel vanes inclined with respect to a plane perpendicular to the axis of said casing and extending substantially radially of and within said nozzle for imparting a spiral motion to the air, a tube concentrically mounted within said nozzle to which said vanes extend, a pilot burner mounted within said concentric tube, and a source of gas under pressure connected to said pilot burner and to said housing for admixture at said discharge opening with the air forced through said casing and nozzle.

CARL J. WESTLIN G.

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

UNITED STATES PATENTS Number Name Date 1,371,490 Keller Mar. 15, 1921 1,418,994 Wales June 6, 1922 1,539,383 Bienenstok May 26, 1925 1,647,675 Vedder Nov. 1, 1927 1,715,584 Wetmore June 4, 1929 2,034,932 Whitcomb Mar. 24, 1936 FOREIGN PATENTS Number Country Date 232,532 Great Britain Apr. 23, 1925

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