US2969833A - Burner mechanism - Google Patents

Description

Jan. 31, 1961 Filed April 11, 1957 S. BLOOM ETAL BURNER MECHANISM FIG.

2 Sheets-Sheet 2 INVENTORS FREDERICK S. BLOOM 8 WALTER RUDIN BURNER MECSM Frederick S. Bloom, Mount Lebanon Township, Allegheny County, and Walter Rodin, Baidwin, Pa.; said Rudin assignor to Bloom Engineering Company, Inc, Pittsburgh, Pa, a corporation of Pennsylvania Filed Apr. 11, 1957, Ser. No. 652,192

6 Claims. (Cl. 158-11) This invention relates to a new burner mechanism having a new cooperating burner and port block of the nozzle-mix class in which combustion air and fluid fuel are separately conducted to the burner, metal parts of which are positioned away from detrimental exposure for use in the wall of a furnace or the like. Further, this invention pertains to such new burner mechanism which in operation uniformly heats the flaring surface of the port in said port block to selected operating temperature with flame stability and retention at the various rates of operation.

Thus, in devices made in accordance with our invention metal parts of our new burners are screened from exposure to highly heated refractory surfaces such as occurs with burners of the radiant class which project into the base of a flaring port in a refractory port block. Further, our new burner mechanisms bring the refractory surface of the port block with which such new burners are used up to selected operating temperature in a relatively uniform fast-acting fashion without the development of a radial streaking or non-uniform radiant condition on the port surface even at lower rates of operation. Moreover, devices of our invention throughout the turndown range below maximum capacity retain in operation a stable flame which remains adjacent to the delivery ends of the discharge passages in the nozzle members of such new burners so that the condition known as blow off is inhibited. In our new burner mechanism, employing a flaring port in the port block and an intermediate stepped flaring portion, operations can be conducted at an operating rate sufliciently low to avoid, when desired, the addition of thermal units to the thermal head in a furnace or the like with which such burner mechanism is employed without loss of that stability and uniformity of performance.

Other objects, advantages and features of this invention will be apparent from the following description and the accompanying drawings, which are illustrative only, in which Figure l is a view in section taken substantially along line 1-1 of Figure 2 showing one embodiment of a burner mechanism of this invention;

Figure 2 is an end view looking at the inner end of the burner mechanism shown in Figure l; and

Figure 3 is a view in section, similar to the section shown in Figure 1, of a modified embodiment of our invention.

A burner mechanism of this invention is shown in Figures 1 and 2 comprising a new cooperating burner 11 and a refractory port block 12 fixed in the wall of a furnace 13, which wall may be in the sides, ends, floor or roof of a furnace or the like. Port block 12 is mounted on a mounting plate 14 which plate 14 is removably affixed to furnace 13. Burner 11 may be suitably affixed to mounting plate 14, for example, by bolts and lugs (not shown). As shown, port block 12 comprises a tubular burner recess 15 at the rear of the port block which is in communication with a flaring port 16.

Fla-ring port 16 has a cylindrical opening 17 at the base of the port and an intermediate stepped flaring portion 18 between opening 17 and the inner flaring surface 19 of port 16. The intermediate flaring portion 18 is so stepped from surface 19 by its intermediate stepping surface 20. A lighting hole 21 extends from surface 19 through the rear of block 12 and through mounting plate 14 for the insertion therein of a lighting burner is usually kept lighted to ignite burner 11 whenever burner 11 is turned on at the beginning of an operation cycle; or, if desired, lighting hole 21 may be omitted and other methods of lighting burner 11 may be employed.

Burner 11 comprises a tubular body 22 which is continued rearwardly by a combustion air casing 23, burner 11 being of the nozzle-mix class in that combustion air and fluid fuel are separately conducted to the interior of that burner. Body 22 fits in recess 15 and the admission of air to any space between body 22 and recess 15 is preferably avoided as by means of the use of a gasket 24 between a flange of casing 23 and mounting plate 14. The front of body 22 is adjacent the back of a refractory shoulder 25 extending between the front of recess 15 and intermediate flaring portion 18. The front of body 22 is closed by a burner tip 26 which has a nozzle member 27 having a rearwardly extending recess 28 therein. The walls of member 27 have combustible mixture discharge passages 29 extending therethrough generally laterally and at a compound angle such that the axes of the passages 29 are convergent inwardly along the axis of burner 11 from the outside of nozzle member 27 and are also tangential to a circle described about that axis. The result is that the combustible mixture issuing from all of the discharge passages 29 rotates in the same direction. Further, the back wall 30 of member 27 is provided with an axial opening 31 in which an insert 32 is provided with an additional central axial discharge passage 33 and oblique discharge passages 34 for the discharge of combustible mixture which is rotated and burned with the bulk of the combustible mixture issuing from the discharge passages 29.

Casing 23 is provided with an internal flange 35 which is rearwardly offset to provide a recess in open communication with the space to the rear of member 27, such recess and space forming a mixing chamber 36. The sides of flange 35' are provided with peripherally spaced combustion air openings 37 extending therethrough. Combustion air is admitted into casing 23 through an inlet 38 and space around a fuel tube 39. Fuel tube 39 extends between a fluid fuel opening '40 in the back of flange 35 and an opening 41 at the back of casing 23. Fuel tube 3'9 is provided with a fuel discharge opening 42 so that fuel leaving opening 42 and air passing through the openings 37 will mix in mixing chamber 36 forming a combustible mixture discharge through the dis charge passages 29, 33 and 34 in nozzle member 27 and insert 32. Such combustible mixture enters the recess 28 in a whirling manner and flames there at all levels of operation of the burner 11 from maximum capacity operation to the minimum rate of operation. The burning mixture whirls about the burner axis through the opening 17 which has the same cross-sectional area as recess 28 and spreads along the surface of the intermediate stepped flaring portions 18 and 21) and the inner flaring portion 19 with the result that at all of said levels of operation the surface of port 16 is substantially and uniformly heated all over at about the same time Without any radial or other streaking on the refractory surface, even though the discharge passages in nozzle member 27 are separate and distinct. Further, stable flame is retained in recess 28 at all levels of turndown and that flame, which on natural gas fuel appears blue in recess 28, is clear and cannot be seen when the surface of port 16 becomes heated in a burner operation. Still further, burner 11 may be turned down far enough without loss of flame stability or maintenance of the flame in recess 28 so that the burner mechanisms will not add significant heat to the interior of furnace 13, which may be desired as in the case of a stoppage in the progress of the work moving through such a furnace. Preferably, an air-fuel ratio controller is used to apportion the combustion air quantity fed to inlet 38 relative to the fluid fuel quantity discharged from fuel tube 39.

As shown, burner 11 is a combination fuel gas and fuel oil burner. Fuel tube 39 is connected to an adapter holder 43 which has a side opening 44 and an axial end opening 4-5. A plug 46 in opening 45 is drilled for the passage therethrough of fuel oil which enters a strainer fitting 47 and then passes through a union 48 to enter the interior of oil atomizer 49. Oil atomizer 49 is provided with an atomizer cap 50 with openings at the end thereof for the discharge of such fuel oil in an atomized condition, with the help of atomizing air or steam admitted through opening 44. Such atomizing air or steam passes into an annular space 51 and thence through lateral passages 52 between cap 50 and the inside of the end of fuel tube 33 adjacent opening 42. Or, if desired, on fuel oil cycle, atomized oil emulsion as such may be fed into the opening through plug 46- for discharge through cap 50 and opening 42, in which case no atomizing fluid medium needs to be admitted through side opening 44. The connection to opening 44 preferably is valved in such a way that burner 11 may be operated on a fuel gas cycle by shutting olf the atomizing air or steam, in which case the oil admission to fitting 47 would also be shut off, and admitting fuel gas to annular space 51 through opening 44, such fuel gas passing through the openings 52 into mixing chamber 36 where it would admix with combustion air for discharge through the discharge passages in nozzle member 27. As shown, burner 11 is adapted to have oil atomizer 49 remain in place although a person operating burner 11 may remove atomizer 49 and plug 45 replacing them with a solid plug to close opening 45 as in a situation when burner 11 is to operate for long periods on straight fuel gas.

In the modification illustrated in Figure 3, parts therein corresponding in structure and functioning to parts shown in the embodiment of Figures 1 and 2. are provided with the same reference numerals with the addition of a prime accent thereto. The Figure 3 embodiment, as shown, is adapted to operate either on fuel gas ad mitted through opening 44-, or on an atomized oil emulsion admitted through opening 44, such fluid fuel passing through the annular opening 42' surrounding an axial burner tube 53-. Burner tube 53 is connected at its forward end to the rear end of an insert 54 which otherwise is similar to insert 32. The outer end of axial burner tube 53 is connected to one side of a plug 46' and continued by tube 53a to a coupling 55 which leads into a mixer fitting 56 supplied with fuel gas through a pipe 57 and with air for the combustion of that fuel gas amount through a connection 53. The gas from pipe 57 and the air from connection 58 mix inside mixer 56 and pass into and through the tube 53 and the insert 54 to serve as a preferably continuously burning small flame in opening 31' and recess 28', whether or not burner 11 is being operated at the time then being. Thus, in burner mechanism embodiment Iii, no lighting hole or lighting burner is needed and the same small supply of gas which feeds the discharge passages in insert 54 will also serve as a continuous lighting source whenever burner 11' is turned on at a selected rate of operation with performance in accordance with that described above. It will also be noted that shoulder 25" may be wide or narrow as desired, sufficient axial length being retained to give the structural strength needed in view of the nature of the refractory used in port block 12'. It will also be noted that intermediate stepped portion 18 and 20' leads into a relatively flat very widely flaring surface 19 and we have discovered that despite such relative flatness of surface 19', uniform heating of the surface of port 16' occurs in an operation of burner 11 with the advantages and features noted above in connection with the embodiments of Figures 1 and 2.

In both embodiments, as the new burner is turned down, the temperature of the surface of the port diminishes and at the lower pressure of such a turned down rate of operation, burning combustible mixture tends to have a more forward firing characteristic than it does at the higher relative rates of fuel and air quantities fed to such burners. In all cases and at all rates of operation, the whirling flame remains ignited and stable in the nozzle member recess without blowing off. The quantity of combustion air relative to the quantity of fuel supplied to burners of our invention in all cases will be sufficient to support combustion but such quantity of combustion air may vary, as desired, from somewhat less combustion air than that needed for complete combustion to an excess of combustion air dependent upon the desired condition ranging respectively from reducing to a somewhat oxidizing condition.

Various changes may be made in the embodiments shown and in details of our new burners and burner mechanism without departing from the spirit of our invention or the scope of the appended claims.

We claim:

1. In a nozzle-mix burner mechanism for a furnace or the like, apparatus comprising, in combination, a refractory port block adapted to fit into an opening in a wall of a furnace or the like, said port block having a burner recess at the rear thereof and a flaring port at the front thereof in communication with said recess through the base of said port, said flaring port having an intermediate stepped flaring portion at the rear of a forward flaring portion nearer to the interior of said surface or the like, a cylindrical burner body adapted to fit against the sides of said recess, a burner tip closing the front of said body adjacent the front of said burner recess, said tip comprising a nozzle member having a rearwardly extending recess therein, said .nozzle member having compound angle combustible mixture discharge passages extending through the wall of said member to discharge into said nozzle recess, an axial discharge passage extending through the back wall of said nozzle member to discharge into said nozzle recess, the cross section of said nozzle recess being substantially unrestricted and equal to and in registry with a port base opening communicating with said intermediate stepped flaring portion, said compound angle discharge passages being directed in a corresponding direction to rotate combustible mixture issuing there from, a combustion air casing connected to said body, said combustion air casing having an internal flange forming an axial recess, combustion air openings extending through the side walls of said flange, a fluid fuel opening extending through the back wall of said flange whereby combustion air and fuel mix to form a com bustible admixture in a mixing chamber in said body in back of said nozzle member for discharge at least through said compound angle discharge passages, an axially ex tending fuel tube closing said fuel opening in said flange, a fuel discharge opening for fluid fuel at the front of said fuel tube, whereby said burner mechanism in operation will provide rotating flame within said nozzle member recess and port which hugs said nozzle member recess and brings the refractory surface of said port uniformly up to and maintains it at operating temperature in accord ance with the selected rate of operation for said burner.

2. In a nozzle-mix burner mechanism for a furnace or the like, apparatus comprising, in combination, a refrac tory port block adapted to fit into an opening in a wall of a furnace or the like, said port block having a burner recess at the rear thereof and a flaring port at the front thereof in communication with said recess through the base of said port, said flaring port having an intermediate stepped portion, an inner flaring portion in said port nearer to the interior of said furnace or the like, a tubular burner body adapted to fit against the sides of said recess, a burner tip closing the front of said body adja' cent the front of said burner recess, said tip comprising a nozzle member having a rearwardly extending recess therein, said nozzle member having compound angle c0mbustible mixture discharge passages extending through the wall of said member and an axial discharge passage extending through the back wall of said nozzle member to discharge combustible mixture into said nozzle recess, the cross section of said nozzle recess being substantially unrestricted and equal to and in registry with a port base opening communicating with said intermediate stepped flaring portion, said compound angle discharge passages being directed in a corresponding direction to rotate combustible mixture issuing therefrom, means for supplying combustion air to said body, and means for selectively supplying atomized fuel oil and fuel gas to said body, whereby combustion air and fuel mix to form a combustible mixture in back of said nozzle member for discharge through said discharge passages.

3. In a nozzle-mix burner mechanism for a furnace or the like, apparatus comprising, in combination, a port block adapted to fit into an opening of a wall of a furnace or the like, said port block having a burner recess at the rear thereof and a flaring port at the front thereof in communication with said recess through the base of said port, said flaring port having an intermediate stepped flaring portion at the rear of a forward flaring portion nearer to the interior of said furnace or the like, a cylindrical burner body adapted to fit against the sides of said recess, a burner tip closing the front of said body adjacent the front of said burner recess, said tip comprising a nozzle member having a rearwardly extending recess therein, said nozzle member having compound angle combustible mixture discharge passages extending through the wall of said member to discharge into said nozzle recess, an axial discharge passage extending through the back wall of said nozzle member to discharge into said nozzle recess, independent means for supplying a combustible mixture to said axial discharge passage, the cross section of said nozzle recess being substantially unrestricted and equal to and in registry with a port base opening communicating with said intermediate stepped flaring portion, said compound angle discharge passages being directed in a corresponding direction to rotate combustible mixture issuing therefrom, means for supplying combustion air to said body, and means for supplying fluid fuel to said body to mix in back of said nozzle member for discharge through said compound angle discharge passages.

4. In a burner adapted to be used with flaring port block for a furnace or the like, apparatus comprising, in combination, a tubular burner body, a burner tip closing the front of said body, said tip comprising a nozzle memher having a rearwardly extending recess therein, said recess being substantially free of lateral restriction, said nozzle member having compound angle combustible mixture discharge passages extending through the wall of said member to discharge into said recess, an axial discharge passage extending through the back wall of said nozzle member to discharge into said recess, said compound angle discharge passages being directed in a corresponding direction to rotate combustible mixture issuing therefrom, means for supplying substantially all combustion air separately to said body, said combustion air casing having an internal flange, combustion air openings extending through said flange, a fluid fuel opening extending through said flange whereby combustion air and fuel mix to form a combustible admixture in back of said nozzle member for discharge through at least said compound angle discharge passages, and an axially extending fuel tube extending to said fuel opening in said flange to discharge fluid for said mix.

5. In a burner mechanism for a furnace or the like, apparatus comprising, in combination, a refractory port block having a burner opening at the rear thereof and a flaring port at the front thereof, said port having an intermediate step portion in the surface of said port flare, a burner having a body positioned in said opening, a closing tip for the forward end of said body comprising a nozzle member forming a rearwardly extending recess therein having lateral and axial combustible mixture discharge passages extending from the interior of said body into said nozzle member recess, said nozzle member recess being substantially laterally unrestricted and in alignment with said flaring port adjacent the rear of said intermediate step portion, said lateral discharge passages being angled to rotate combustible mixture discharged thereby, and means for admitting combustion air to one portion of said burner and fluid fuel to said another portion of said burner for combustible admixture in a mixing chamber at the rear of said discharge passages.

6. In a burner mechanism for a furnace or the like, apparatus comprising, in combination, a refractory port block having a burner recess at the rear thereof and a flaring port at the front thereof, said port having an intermediate flare in stepped relation to the remainder of said flare, a burner having a body in said recess, a closing tip for the forward end of said body comprising a nozzle member forming a rearwardly extending recess therein having lateral and axial combustible mixture discharge passages extending from the interior of said body into said nozzle member recess, said nozzle member recess being substantially laterally unrestricted and in alignment with said flaring port adjacent the rear of said intermediate flaring portion, said lateral discharge passages being tangentially angled to rotate combustible mixture discharged thereby, means for admitting combustion air to one portion of said body and fluid fuel to said another portion of said body for combustible admixture in a mixing chamber at the rear of said discharge passages, at least said lateral discharge passages being in communication with said mixing chamber.

References Cited in the file of this patent UNITED STATES PATENTS 794,545 Phillips July 11, 1905 1,231,726 Gault July 3, 1917 1,3 04,402 Spire May 20, 1919 1,800,617 Forster Apr. 14, 1931 2,368,370 Maxon Jan. 30, 1945 2,561,795 Hess July 24, 1951 2,579,215 Nuyl Dec. 18, 1951 2,596,341 McCreery May 13, 1952 2,672,190 Schuman Mar. 16, 1954 2,753,925 Campbell July 10, 1956 FOREIGN PATENTS 180,350 Austria Nov. 25, 1954 486,587 Italy Nov. 11, 1953 306,495 Switzerland Apr. 15, 1955 UNITED STATES PATENT OFFICE CETIFICATION OF CORRECTION Patent No, 2,969,833 January 31, 1961 Frederick S Bloom et a1a It is hereby certified that error appears in the ent requiring correction and that the said Letters Pat corrected below.

above numbered patent should read as Column 3, line 4, for "mechanisms," read we mechanism column 4, line 8, for "embodiments" read embodlment line 39, for "surface read furnace column 6, llne 4, for "combust on" read combustion Signed and sealed this 13th day of June 1961,,

(SEAL) Attest:

ERNEST W. SWIDER DAVID L. I Attesting Officer Commissioner of Patents

Images