US2757723A

US2757723A - Fuel burner nozzle and assembly

Info

Publication number: US2757723A
Application number: US254067A
Authority: US
Inventors: Floyd F Schlitt
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-10-31
Filing date: 1951-10-31
Publication date: 1956-08-07
Anticipated expiration: 1973-08-07

Description

Aug. 7, 1956 F. F. SCHLITT 2,

FUEL BURNER NOZZLE AND ASSEMBLY Filed Oct. 51, 1951 INVENTOR. FLOYD f? SCHL/TT BY E/CHEK WA 775, EDGEEI'ON a M-wQvA/Y United States Patent FUEL BURNER NOZZLE AND ASSEMBLY Floyd F. Schlitt, Elyria, Ohio Application October 31, 1951, Serial No. 254,067

7 Claims. (Cl. 158-115) The present invention relates generally to fluid fuel burner assemblies and is more particularly concerned with a novel burner nozzle and a new burner nozzlepilot assembly.

The problem of igniting fuel at the nozzle of a fluid fuel burner has received the attention of many workers skilled in the art over a long period of time. For some purposes and in case of some types of burners, the problem has been entirely disposed of through the invention of thoroughly satisfactory ignition means. In other instances, however, the problem is still very much in existence because heretofore no one has been able to devise a completely satisfactory solution. For example, no ignition means and burner nozzle combination which is satisfactory from the standpoint of relatively long, trouble-free service life is commercially known today. In the usual gas conversion burner construction which is designed for home use, for instance, the service life of the pilot burner is limited to a relatively short period so that this item constitutes an important economic factor in the use of these burners. In these conversion burners it is, of course, absolutely essential from the safety standpoint and because of the laws governing the design and operation of these devices, that the pilot burner be located where the pilot flame will always be in a position relative to the main burner nozzle to assure ignition of gas issuing therefrom. This requirement has always carried with it the necessity for locating the pilot burner in a zone of high temperature closely adjacent to the main burner nozzle outlet opening. As a result, damage or destruction of the pilot burner occurs in a short period of use.

In accordance with my invention all the requirements, legal and otherwise, as to the installation and operation of gas conversion burners may be completely satisfied, while at the same time their pilot burners are removed from the relatively high temperature zone of their prior art environment. In other words, in accordance with this invention, the useful life of the ordinary pilot burner can be greatly prolonged without impairing the function or the efiiciency of the pilot burner in the ignition of the combustible fuel mixtures delivered through the main burner nozzle outlet.

As another advantage of this invention, gas-air mixtures at the main burner nozzle may be ignited by the pilot burner even though the pilot flame is extinguished. Thus, in the newer type of pilot burners employing thermocouples in the head portion and having a plurality of relatively small openings for escape of fuel to support small secondary pilot flames or theimocouple heating flames, the main burner nozzle may be ignited by these small flames in the absence of the main pilot flame itself. With the advent of this newer type of pilot burner, some cities have enacted or are about to enact codes requiring installation of these pilot burners in such a way that the ignition result will be obtained intheabsence' of the main pilot flame. But for this invention, it would be necessary under these codes to place the pilot burner i ice at least partially across the outlet port of the main burner nozzle, thereby subjecting the pilot burner head portion to even more severe service conditions than it has had to endure in the earlier types of installation.

As still another advantage of this invention, the length of pilot flame required to assure ignition of combustible mixtures of fluid fuel issuing from the main burner nozzle can be substantially reduced regardless of the width of the outlet end wall of this nozzle without moving the pilot burner closer to the nozzle outlet and into the higher temperature zone surrounding that outlet. This means that a more stable and dependable pilot flame can be used than has been possible heretofore under the same general circumstances. It also means that ignition can be dependably obtained by means of the thermocouple heating flames of the pilot, particularly in those instances where a burner nozzle of thin wall section, such a nozzle shell formed of thin pressed steel, is engaged.

Those skilled in the art will gain a further and better understanding of this invention on consideration of the following detailed description of three preferred embodiments of this invention, reference being had to the drawings accompanying and forming a part of this specification; in which:

Fig. 1 is a side elevational view of a burner nozzlepilot burner assembly in which the nozzle is shown in cross-section and the pilot burner is disposed in novel relation thereto in accordance with this invention;

Fig. 2 is an end view of the assembly of Fig. 1, showing how the pilot flame is directed by the pilot burner into the main burner nozzle;

Fig. 3 is a view like Fig. 1, but shows an alternate form of burner nozzle of this invention;

Fig. 4 is an end view of the Fig. 3 assembly; and,

Fig. 5 is a fragmentary, side elevational view of an assembly of a pilot burner and another form of burner nozzle of this invention, said nozzle being shown in crow section.

Briefly, a fluid fuel burner nozzle of the present invention comprises a hollow body having a side wall and inlet and discharge ports at its opposite ends, this side wall being provided with a slot extending from the discharge port generally longitudinally of the body toward the inlet port. More specifically, in a preferred form my novel burner nozzle comprises a shell having fuel inlet and discharge ports at its ends, a nozzle inside the shell having an inlet portion merging with the shell inlet and outlet portion spaced from the shell to define an open chamber in communication with the shell and nozzle outlets. The wall of this inner nozzle has an aperture establishing communication with the interior of the inner nozzle and the said open chamber, and the shell has a slot which extends from the discharge port generally longitudinally toward the inlet port.

The novel assembly of this invention accordingly may be defined as comprising a fluid fuel burner nozzle as defined above, and a burner pilot element having a pilot flame nozzle adjacent to the burner nozzle shell to direct a pilot flame into the open chamber in the said shell through the longitudinally extending slot provided for that purpose in the shell.

Referring to the drawings, in Fig. l a burner nozzle N and a pilot burner P are shown in a normal assembled relation, according to my invention. Burner nozzle N comprises a generally cylindrical shell 10 having an inlet port 12 at one end and an outlet port 14 at the other end, the outlet port being defined by an annular end wall portion 15. The nozzle has an annular inner wall portion 17 of generally conical shape which is integrally formed with the shell and merges therewith nearer inletport 12 than outlet port 14 to define an inner nozzle. Inner wall 17 terminates Within shell 10 adjacent to but spaced from end wall 15 and outlet port 14 and itself defines a discharge or outlet port 19 which is coaxial with

ports

12 and 14 but of reduced diameter compared to them. Thus, an annular chamber 20 is defined within shell forwardly of the inner wall 17 and this chamber is open to the interior of the inner nozzle through port 19 of said inner nozzle and is Open to the atmosphere through outlet port 14. In addition, there is communication between chamber 20 and the interior of the inner nozzle through four apertures 22 through inner wall 17, these being spaced uniformly and directed at an angle to the axis of shell 10 so that gases flowing through the nozzle N may be diverted in part through these apertures and directed generally forwardly of the nozzle into chamber 20.

A slot 25 is provided in shell 10 and extends through a portion of end wall and longitudinally of the shell to a point adjacent to the junction of inner wall 17 and the shell. Slot 25 is disposed in register with one of the apertures 22 so that gas passing through this aperture into chamber will be directed toward slot 25.

In this Fig. 1 assembly, pilot burner P is disposed with its head portion 30 adjacent to shell 10 in such a position as to direct a pilot flame 32 into chamber 20 through slot 25, as illustrated in Figs. 1 and 2. Head 30 also is so situated that gas flowing through slot will come into contact with thermocouple flames 33 thereof and be ignited thereby if principal pilot flame 32 is extinguished at the time.

In reference to the Fig. 3 assembly, the same pilot burner P is employed again, but the burner nozzle 40 differs from nozzle N in certain respects. Nozzle 40 is like nozzle N in that it comprises a shell 42 having an inlet port 43 at one end and a discharge port 44 at the other end, the latter being defined by an end wall 45. Shell 42. however, is of generally rectangular shape in transverse cross section, as illustrated in Fig. 4. Nozzle 40 has an inner wall portion 47 merging with the shell side walls between inlet and

outlet ports

43 and 44 and defining an inner discharge nozzle opening 49. Whereas inner nozzle wall 17 of burner nozzle N is generally conical, inner wall 47 of this Fig. 3 device is in the form generally of a four-sided pyramid. Also, inner wall 47 is provided with apertures 52 at its corners for flowing gas from the interior of the nozzle into a chamber 54 defined in the shell by inner wall 47 and end wall 45 and the side walls of shell 42. In one of these side Walls approximately midway between two corners of the shell a slot 55 is provided and this slot extends through end wall 45 to the nozzle discharge port 44. Slot 55 terminates short of the point of merger of inner wall 47 and the side of shell 42.

In this assembly, as in the Fig. l assembly, nozzle 40 and pilot burner P are disposed adjacent to each other with head of the pilot burner being situated to direct pilot flame 32 into chamber 54 for the purpose of igniting the fuel contained therein. It is also to be noted that by virtue of the manner of the location and relation of pilot burner P to the nozzle 40, gas issuing from nozzle through slot 55 will be ignited by thermocouple flames 33 if flame 32 is not burning.

From the foregoing it will be understood that despite the structural difl erenccs between the two embodiments of the invention illustrated and described above, the novel advantages of this invention may be obtained because the function and etfect of these devices is generally the same. In each instance, combustible mixtures of fluid fuel, such as natural gas and air, atomized fuel oil or powdered coal and air, delivered to the burner nozzle and flowing through its inlet port, through the inner nozzle outlet portion, and through the apertures in the inner wall of the nozzle into the open chamber in the nozzle shell, will be ignited by the pilot flame coming into contact with this fuel in the nozzle shell and ignition of the burner is thus accomplished in effect before the gas issues from the nozzle outlet port. This novel ignition system and assembly accordingly has the advantages defined above and the additional advantage of producing ignition more quickly and perhaps more dependably than any gas conversion burner heretofore known. This latter result would be attributable to the fact that contact of flame with the gas to be ignited is effected within the nozzle itself, where concentration of the fuel is at an ideal level for ignition and where the pilot flame will not be subject to strong currents of air which would tend to prevent ignitionproducing contact between the pilot flame and the burner fuel.

Referring to the embodiment of the invention illus trated in Fig. 5, here again, the assembly includes pilot burner P, suitably of the newer conventional design and construction described above, and a nozzle 60 disposed adjacent to the pilot burner after the manner illustrated in Figs. 1 and 3. Nozzle 60 comprises a shell 61 having an inlet port 62 at one end and an outlet port 64 at the other end and has an annular inner wall portion 67 integrally formed with the shell and merging therewith. Nozzle 60 is of relatively thin wall section and is provided with a slot 69 in an end wall 70. End wall 70, like end wall 45 of the Fig. 2 device, defines outlet port 64 and an open chamber 72 is defined just inside this port through the cooperation of inner wall 67 and the shell side and end walls. Wall 67 defines an outlet port 68 and is provided with slot-like apertures 74 spaced around port 68 which communicate with the interior of the inner nozzle and open chamber 72 for the flow of combustible gas mixtures from within the inner nozzle into chamber 72, as described above. Slot 69 opens into discharge port 64 and also opens into chamber 72 and it extends radially from port 64 to the side wall of the shell.

Pilot burner P is disposed beside nozzle 60 with its head portion 30 extending forwardly of end wall 70 so that main pilot flame 32 is directed lengthwise of slot 69 toward port 64 to assure ignition of the combustible gas mixtures flowing from port 64 and the slot. It will be also noted that by virtue of the advanced position of pilot burner head 30 relative to nozzle 60, the thermocouple heating flames 33 directed toward port 64 are s located as to be capable independently of igniting combustible gas mixtures issuing through port 64 and slot 69.

It will accordingly be understood that some of the more important advantages of this invention stated hereinabove are to be realized through the use of this Fig. 5 assembly. It will be seen, for example, that ignition of combustible gas mixtures issuing from nozzle 60 will be assured in this assembly, regardless of whether flame 32 is effective, by virtue of the novel construction of nozzle 60 as described, and by virtue of the novel relationship of this nozzle element with the pilot burner P, as shown.

Having thus described the present invention so that those skilled in the art may be able to gain a better understanding and practice the same, I state that what I desire to secure by Letters Patent is defined in what is claimed.

What is claimed is:

1. A burner nozzle comprising a shell having fuel inlet and discharge ports at its ends, a nozzle within said shell having an inlet portion merging with said shell inlet and an outlet portion spaced from said shell to define an open chamber in communication with said shell and nozzle outlets, the wall of said nozzle having an aperture establishing communication between the interior of said inner nozzle and said open chamber, and said shell having a slot in register with said aperture and extending from said discharge port generally longitudinally toward said inlet port and terminating adjacent to the junction of the shell and the inner nozzle.

2. A burner assembly including a nozzle comprising a shell having fuel inlet and discharge ports at its ends. a nozzle within said shell having an inlet portion merging with said shell inlet and an outlet portion spaced from said shell to define an open chamber in communi-.

cation with said shell and nozzle outlets, the wall of said nozzle having an aperture establishing communication between the interior of said inner nozzle and said open chamber, and said shell having a slot extending from said discharge port generally longitudinally toward said inlet port, and a burner pilot element having a pilot flame nozzle disposed adjacent to said shell to direct a pilot flame into the shell through the said slot.

3. A burner assembly including a nozzle comprising a shell having fuel inlet and discharge ports at its ends, a nozzle within said shell having an inlet portion merging with said shell inlet and an outlet portion spaced from said shell to define an open chamber in communication with said shell and nozzle outlets, the wall of said nozzle having an aperture establishing communication between the interior of said inner nozzle and said open chamber, and said shell having a slot in register with said aperture and extending through the shell to provide communication between the chamber and the exterior of the shell, and a burner pilot element having a pilot flame nozzle disposed adjacent to said shell to direct a pilot flame into the shell through the said slot and into contact with a combustible fluid fuel mixture in said chamber and flowing in the direction of said slot from said aperture.

4. A burner assembly including a nozzle comprising a shell having fuel inlet and discharge ports at its ends, a nozzle Within said shell having an inlet portion merging with said shell inlet and an outlet portion spaced from said shell to define an open chamber in communication with said shell and nozzle outlets, the wall of said nozzle having an aperture for permitting fuel to flow from the interior of the nozzle into the chamber, and said shell having a slot opening into said open chamber in register with the aperture and terminating forwardly of the junction of the shell and the inner nozzle wall, and a burner pilot element having a pilot flame nozzle disposed adjacent to said shell to direct a pilot flame toward the said slot for igniting fuel gases in the chamber.

5. A burner nozzle comprising an outer shell having a fuel outlet port at its discharge end and a fuel inlet port spaced from the discharge port and communicating therewith, an inner shell within the outer shell having an inlet opening communicating with the inlet port to receive fuel flowing through the nozzle toward said discharge port and having a main outlet opening in its outer end of diameter less than the diameter of said discharge port, the outer end of the inner shell being spaced axially inwardly from the discharge end of the outer shell a distance less than the diameter of the main outlet opening of the inner shell, the inner and outer shells cooperating to define in the nozzle a combustion chamber between the inner shell and the surrounding portion of the outer shell, said chamber communicating with the discharge port through the space between the outer end of the inner shell and the surrounding portions of the discharge end of the outer shell, said inner shell having an auxiliary aperture of diameter substantially less than the diameter of the said main opening communicating with the inlet opening and with the combustion chamber for delivery of fuel into said chamber, and said outer shell having a slot in its discharge end portion opening into the combustion chamber.

6. A burner nozzle comprising an outer shell having a fuel outlet port at its discharge end and a fuel inlet port spaced from the discharge port and communicating therewith, an inner shell within the outer shell having an inlet opening communicating with the inlet port to receive fuel flowing through the nozzle toward said discharge port and having a main outlet opening in its outer end of diameter less than the diameter of said discharge port, said main outlet opening and discharge port being disposed substantially coaxially and the outer end of the inner shell being spaced axially inwardly from the discharge end of the outer shell a distance less than the diameter of the main outlet opening of the inner shell, the inner and outer shells cooperating to define in the nozzle a combustion chamber between the inner shell and the surrounding portion of the outer shell, said chamber communicating with the discharge port through the space between the outer end of the inner shell and the surrounding portions of the discharge end of the outer shell, said inner shell having a plurality of auxiliary apertures of diameter substantially less than the diameter of the said main opening communicating with the inlet opening and with the combustion chamber for delivery of fuel into said chamber, and said outer shell having a slot in its discharge end portion opening into the combustion chamber and extending to a point between the inner end of the combustion chamber and the outer end of the inner shell.

7. A burner nozzle comprising an outer shell having an end Wall defining a fuel outlet port at its discharge end and a fuel inlet port spaced from the discharge port and communicating therewith, an inner shell within the outer shell having an inlet opening communicating with the inlet port to receive fuel flowing through the nozzle toward said discharge port and having a main outlet opening in its outer end of diameter less than the diameter of said discharge port, the outer end of the inner shell being spaced axially inwardly from the discharge end of the outer shell a distance less than the diameter of the main outlet opening of the inner shell, the inner and outer shells cooperating to define in the nozzle a combustion chamber between the inner shell and the surrounding portion of the outer shell, said chamber communicating with the discharge port through the space between the outer end of the inner shell and the surrounding portions of the discharge end of the outer shell, said inner shell having a plurality of auxiliary apertures of diameter substantially less than the diameter of the said main opening communicating with the inlet opening and with the combustion chamber for delivery of fuel into said chamber, and said outer shell having a slot in its end wall opening into the combustion chamber and extending radially outwardly to the side of the outer shell.

References Cited in the file of this patent UNITED STATES PATENTS 2,110,217 Gardner Mar. 8, 1938 2,533,143 Scharbau et al. Dec. 5, 1950 2,569,356 Turpin Sept. 25, 1951 FOREIGN PATENTS 683,439 Germany Nov. 6, 1939 122,840 Australia Dec. 5, 1946