US 3022815 A
Description (OCR text may contain errors)
Feb. 27, 1962 F. s. BLOOM ETAL 3,022,815
BURNER MECHANISM Filed March 31, 1958 2 Sheets-Sheet 1 r l U 20 34 r3 7 f "35 D\ INVENTORS I femfe/a 5.40044 & W447i? PUD/N THE/P AfI'OPNE/S Feb. 27, 1962 F. s. BLOQM ETA]. 3,022,815
BURNER MECHANISM 2 Sheets-Sheet 2 Filed March 31, 1958 n a a INVENTORS FEEDER/CV5. BLOOM &
W447i? PUD/N THE/1P ATTORNE/S m flmwa M finite States 3,022,815 nunnnn Il/lECHANlSM This invention relates to a new port mix burner mechanism having a new cooperating burner and port block in which combustion air and fluid fuel are separately conducted to and through the burner, such burner preferably being utilizable in the wall of a furnace or the like. Further, this invention is an in-part continuation of application for United States Letters Patent Serial No. 652,192, filed by us on April 11, 1957, now Patent No. 2,969,833.
Burner mechanism embodiments of this invention comprising cooperating relatively unexposed burners and port blocks provide relatively stable and uniform flame and heating conditions over a wide range of operating rates, appear to reduce recirculation into the burner port from the furnace interior and enable fuel and bulk combustion air to be brought together on the outside front of the burner with consequent avoidance of burn back or flash conditions. Gther objects, advantages and features of this invention will be apparent from the above-identified application and from the following description as well as the accompanying drawings, which are illustrative only, in which FIGURE 1 is a view in section taken substantially along line I-I of FIGURE 2 showing one embodiment of a burner mechanism of this invention adapted to use fuel gas;
FIGURE 2 is a view of the front or inner end of the burner mechanism embodiment shown in FIGURE 1;
TGURE 3 is a view of the embodiment shown in FIGURES 1 and 2 taken along line III-III of FIGURE 1; and
FIGURE 4 is a view in section, similar to the section shown in FIGURE 1, of a modified embodiment of our invention utilizable with fuel oil or fuel gas.
Referring to the drawings, a burner mechanism of this invention utilizable with fuel gas is illustratively shown in FIGURES l to 3, inclusive. Therein, a burner 11 cooperates with a port block 12 preferably of refractory which may be fixed in a wall 13 of a furnace or the like. Such wall may be one or more sides, ends or the floor or roof, as the case may be. Block 12 preferably is mounted on a mounting plate 14 which may be removably aflixed to a steel shell 15 around the outside of a furnace.
As shown, port block 12 comprises a tubular burner recess 16 at the rear thereof in communication with a flaring port 17. Port 17 is provided with a port base opening 18 and an intermediate stepped portion 19 having a flaring surface 20 and a cylindrical surface 21 in the illustrated embodiment. Such diverging portion 19 comprises an annular recess between the portions 18 and the final front flaring portion 22 of the port 17. The slope or slopes of the intermediate portion 19 may-have more than one configuration or angle relative to the axis of block 12.
A pilot burner lighting hole 23 extends from surface 22 through the rear of the block inclusive of plate 14, the lighting hole 23 normally being closed by a pilot burner (not shown). If desired, the lighting hole 23 and pilot burner may be omitted in the event that the burner 11 in operation is manually or otherwise lighted at the start of its functioning.
Burner 11 comprises a cylindrical body 24 which is continued rearwardly by a burner housing 25 having a.
atent I through an orifice-32' to tube-44and thence to atomizergas pipe 30 and a fuel tube 31. Appropriate gaskets are provided between portions of the burner and between the burner and the mounting block to avoid air infiltration. Thereby, the amount of combustion air admitted to the interior of burner 11 is as selected by the air-fuel ratio controller or other means employed'to feed combustion air at a selected rate to the burner in the course of operation. An orifice 32 of a selected size preferably is provided in fitting 29 whenever a series of burner mechanisms 10 are mounted in furnace wall 13 and fed from a common fluid fuel source so that at a given pressure each burner will operate relatively uniformly on the fuel supplied.
The front of body 24 is closed by a nozzle 33 having one or more axial tiers of combustion air openings 34 extending between the interior of burner-11 and a mixing chamber 35 on the front side of nozzle 33, said mixing chamber being continued in a forward axial direction by port base opening 18. The combustion air passageways 3 4 are angled in acompound direction with respect to the axis of the burner and further in thatthe axes of the passageways 34 are tangential in the same direction to a circle circumscribed about the axis of the burner and fuel tube, as illustrated in FIGURE 2.
Fuel tube 31, as shown, has its forward end threaded to engage a corresponding thread in a central fuel discharge passage 36 passing entirely through the back of nozzle 33. The rear end of tube 31 is contained in a bore 37 on the forward end of fitting 29 and a resilient O-ring 38 is used to seal the space between the outside of tube 31- and theinside of bore 37 without hampering expansion and contraction effects due to thermal differences which may occur.
We have discovered that even with a fast burning fuel gas like coke oven gas having a high hydrogen content and preferably using preheated air We are able to bring the fuel and combustion air together on the front side of burner 11 in recess 35 and passage 18 in a whirling manner with remarkable stability of flame and flexibility of operation in terms of the turndown range. Moreover, on light-up the surface of the port 17 will quickly heat and become a relatively uniformly heated port block surface,v
normally incandescent at usual fuel operating levels from the rearmo'st portion of passage 18 to the front edge of port surface 22. Still further, it appears that the new burner markedly inhibits recirculation of furnace atmosphere into the port 17 with advantage in that materials which might otherwise deposit on the port surface remain in the furnace proper, or at least out of contact with the surface of port 17.
Y A further embodiment of a port mix burner mechanism of this invention is illustrated in FIGURE 4 wherein portions corresponding generally in construction and functioning are prov ded with the same reference numerals with the addition of a prime accent thereto. Burner 11' is primarily a fuel oil burner, although it may also be utilized to burn fuel gas and be a combination oil and gas burner. In burner 11, the fitting 29 is internallythreaded at its forward end to hold a fuel tube 31' in which an atomizer casing 39 fits. Atomizer casing 39 is annularly threaded and flanged at its rear end.
40 to engage and be held by fitting 29; The front end of casing 39 is provided with a dischargeopening 41 in the front face of member 39. The rear of that front face is beveled as illustrated to engage the front end of an atomizer cap or head 42 hav ng radial converging slots 43 extending from the outside toward. the axial center opening thereof. An oil tube 44 supplies oil Patented Feb. 27, 1962 aces-e15 head 42. Such atomizer 42 and the face portion of casing 39 preferably are constructed in accordance with the teach'ng of application for United States Letters Patent Serial No. 485,367, filed February 1,1955.
Atomizing air or steam is fed to the interior of fitting 29' and of casing 39 around the outside of the atomizer proper through a valved pipe 45, such fluid atomizing agent passing through the slots 43 to strike oil discharged from the center of head 42, the atomized fuel passing through opening 41 which, as shown, empties into the front end of tube 31' in open communication with recess 35' and passage 18'. The oil fed to oil tube 44 preferably first passes through a strainer 46 and a plug 47 threaded into the back of fitting 29', the plug 47 having the orifice 32 therein.
Should it be desired to have burner mechanism It operate on fuel gas, the '1 and atomizing medium should be shut off by shutting off pipes 44 and 45. Fuel gas may be admitted through a valved fuel gas pipe connected to a tapped opening 48 which may be provided in fitting 29'. Other ways of supplying fuel gas to burner 11' can be provided such as having a three-way valve connection in pipe 45 so that as fuel gas is admitted thereto, atom'zing medium in the form of atomizing air or steam is cut off, and vice versa. Such fuel gas in the illustrative situations would pass out through opening 41 after flowing through the beveled slots 43. If desired, the oil atomizer tube 44 and cap 42 can be backed off by backing out plug 47 somewhat, without destroying the sealed condition of the interior of the burner, to provide a'larger opening between the rear side of the front face of casing 39 and the front end of cap 42. In cases where the fuel gas may be dirty, the oil tube 4d and cap 42 can be entirely removed by removing plug 47 from fitting 29 and closing the opening for plug 47 by a threaded plug without any opening therethrough.
The burner mechanisms illustrated may be used also with unheated combustion air and the quantities of combustion air used may range from excess quantities to quantities less than theoretical but which are combustion-supporting quantities depending upon the effect desired, as will be understood by those having ordinary skill in the art to whom this invention is disclosed. Varieties -of fluid fuels both liquid and gas may also be utilized and various changes in details of the illustrated embodiments and other embodiments may be provided without departing from the spirit of this invention or the scope of the appended claims.
1. In a port mix radiant burner mechanism for a furnace or the like, apparatus comprising, in combination, a port member for said furnace or the like having a port with a refractory port surface and a port base open'ng toward the rear thereof through which a burner discharges, said refractory port surface extending substantially from said port base opening to the front of said port member, an annular recess formed in said refractory port surface of larger diameter than said port base opening and between said port base opening and the inner portion of said port, said annular recess being reentrant relative to the adjo'ning portion of said refractory port surface inwardly of said annular recess, said refractory port surface being relatively widely diverging and substantially uninterrupted inwardly-of said annular recess, a tubular burner in alignment with and rearwardly'of said port base opening, said burner having a fixed substantally closed front end member positioned rearwardly of said annular recess, inwardly directed combustion air passageways extending through said front end member and spaced around the axis of said burner, said combustion air passageways having discharge ends adapted to discharge tangentially relative to a circle descr.bed about said axis, said closed front end member of said burner having a rearwardly extending recess in tercepting said discharge ends of said combustion air passageways and a fuel opening extending through said member, fuel supplying means connected to said fuel opening, means to supply combustion air to the interior of sad burner exteriorly of said fuel supplying means, and means to supply fluid fuel to the interior of said fuel supplying means, whereby combustion air and fuel commingle on the recessed side of said front end member of said burner to provide a whirling stable flame to hug said member and spread out over said surface of said port.
2. In a port mix radiant burner mechanism for a furnace or the llke, apparatus comprising, in combination, a refractory port block having a port surface and a port base opening at the rear thereof through which a burner discharges, a flaring port extending substantially from said port base opening to the front of said port block, a substantially peripherally uninterrupted generally step-shaped anular recess formed in said port surface between said port base opening and the front of said port, said annular recess be'ng generally indented relative to the surface of said port adjoining each edge of said annular recess, the surface of said flaring port forwardly of said annular recess being substantially uninterrupted and the included angle thereof being sufiicient to enable said port to serve as a radiant heating port, a tubular burner to fit substantially close to said port base opening, said burner having a generally rearwardly recessed front end nozzle fixed therein rearwardly of said annular recess, a plurality of combustion air passageways extending through said front end nozzle at a cornpound angle in uniformly spaced arrangement around the axis of said burner, said combustion air passageways having discharge ends extend ng in the same angular di rection relative to the axis of said burner to direct combustion air somewhat forwardly and tangentially relative to a circle described about said axis, said rearwardly recessed front end nozzle of said burner being cup-shaped, a back wall in said cup-shaped recess and a centrally located fuel open'ng extending therethrough, said front end nozzle having a periphery substantially behind the portion of said port block around said port base opening, a fuel tube having at least one end generally unconstricted and connected to said fuel opening, means to supply combustion air to the interior of said burner around said fuel tube, and means to supply fluid fuel through the interior of said fuel tube, whereby combustion air and fuel commingle on the cup-shaped recess side of said front end nozzle of said burner to provide a whirling stable flame to hug said front end nozzle and spread out over said surface of said port.
3. In a port mix radiant burner mechanism for a fur? nace or the like, apparatus comprising, in combination, a refractory port block adapted to fit into an opening in a furnace enclosure or the like, said port block having a burner recess at the rear thereof and a flaring generally conical port at the front thereof in communication witht said burner recess through a port base opening in said port, said flaring port having a port surface and a peripherally uninterrupted intermediate stepped annular t recess formed in said port surface at the rear of a forward flaring portion nearer to the interior of said furnace or the like, said annular recess being of larger diameter relative to said surface of said port along each edge of said annular recess, said flaring portion having a relatively uninterrupted slopewith an included angle 'of at least about a cylindrical burner body adapted to fit in said burner recess, a metal burner nozzle fixed to and closing the front of said body adjacent the front of said burner recess and having a back and side wall defining a rearwardly extending cylindrical recess to form a mixing chamber on the front side of said nozzle, said nozzle having a plurality of substantially straight combustion air discharge passageways extending inwardly and forwardly througha wall of said nozzle at a compound angle relative to the uis of said nozzle to discharge inwardly and tangentially into said chamber, an axial fuel discharge passageway extending centrally through said back wall of said nozzle to discharge into said chamber, the cross section of said chamber being substantially equal to and in registry with said port base opening communicating with said intermediate stepped annular recess, said combustion air discharge passageways being directed in a corresponding direction to rotate combustion air issuing therefrom, a burner housing connected to said body, a fluid fuel conduit extending between said burner 10 housing and said fuei discharge passageway to enable combustion air and fuel to come together in said mixing chamber and discharge through said port base opening in a whirling manner, and metering orifice means for said fuel operatively connected to said conduit at least adjacent the rear portion thereof, whereby said burner mechanism in operation may be operated in concert with others and will provide rotating flame within said chamber and port which brings the refractory surface of said port relatively uniformly up to and maintains it at operating temperature in accordance with the selected rate of operation for said burner.
References Cited in the file of this patent UNITED STATES PATENTS 794,545 Phillips July 11, 1905 1,879,916 Bagley Sept. 27, 1932 2,368,370 MaXon Jan. 30, 1945 FOREIGN PATENTS 180,350 Austria Nov. 25, 1954 France Dec. 22, 1956