US2561194A - Internal gas burner - Google Patents

Description

July 17, 1951 A. A. EuRczYK INTERNAL GAS BURNER Filed July 51, 1946 Wir-mmm Patented July 17, 1951 INTERNAL GAS BURNER Alfons A. Furczyk, Philadelphia,

Pa., assignor to Selas Corporation of America, Philadelphia, Pa., a corporation of Pennsylvania Application July 31, 1946, Serial No. 687,264

2 Claims.

My invention relates to burners, and more particularly to burners of the type having a substantially closed combustion space in which practically complete combustion of a combustible gaseous mixture is accomplished and from which heated products of combustion are discharged through a restricted outlet in the form of a high temperature gas stream.

Burners of this type usually are provided with an outer metal shell or housing in which is disposed a hollow refractory body whose cavity forms the substantially closed combustion space. The metal housing is formed with an opening through which the restricted outlet end of the refractory body projects, so that the high temperature gases issuing from the restricted outlet will not come in contact with the metal housing.

In many heating applications the metal shells or housings are provided with brackets for mounting the burners in suitable fixtures of a machine. In addition to mounting the burner shells or housings in definite positions on machines in this manner, it is often necessary to locate the refractory bodies accurately within the metal shells or housings. This is particularly true when the burners are formed with elongated narrow slots which must assume definite positions with respect to work adapted to move into the high temperature gas streams at regions closely adjacent to the restricted outlets of the burners.

It is an object of the invention to provide an improvement in burners of the above type whereby the restricted outlet end of the burner can be accurately positioned within the outer metal shell or housing without the use of a jig or similar mechanism, thereby simplifying and reducing the cost of manufacture of the burners. I accomplish this by providing an outer metal shell and refractory body therefor which are formed in such a manner that the restricted outlet end of the body can be accurately positioned within the shell and precisely locate the position of the restricted outlet with respect to the shell.

The above and other objects and advantages of the invention will be more fully understood upon reference to the following description and accompanying drawing forming a part of this specification, and of which Fig. 1 is a vertical sectional View of a burner embodying the invention; Fig. 2 is an end view, partly broken away and in section, looking toward the restricted outlet or discharge orice of the burner illustrated in Fig. l; Fig. 3 is an end view similar to Fig. 2 which shows only the restricted narrow open end of the outer shell, the refractory hollow body being omitted to illustrate the invention more clearly; and Fig. 4 is a fragmentary vertical sectional view similar to Fig. 1 illustrating the restricted outlet end of the refractory body being accurately positioned within the outer metallic shell.

Referring to the drawing, the gas burner ernbodying the invention includes a ring-shaped base member ll formed to provide an inlet chamber I2 having a threaded opening iii which is adapted to be connected to a suitable source of supply of a combustible gaseous mixture. The base member Il is formed with an inwardly extending shoulder l5 at the top part of the inlet chamber i2 to receive the lower flanged end IS of a circular burner screen Il having a plurality of small apertures I8 extending therethrough.

At the top face of the base member I l is secured a ring-shaped clamping plate i9, as by screws 20, for example, the inner edge of which overlies the flanged end It of the burner screen Il. 'in order to obtain a gas-tight seal about the burner screen Il, a gasket 2l of suitable material, such as asbestos, for example, is interposed between the plate I9 and base member i l.

The large open end of a cup-shaped metal shell or cuter casing 22 is removably secured at 23 to the base member l l. Within the metal shell 22 is provided a hollow body having a cavity forming a combustion space 2li terminating at its upper end in a slotted discharge orifice or restricted outlet 25.

In the embodiment of the invention illustrated the hollow body comprises a number of parts or members of high temperature refractory material including a hollow body or annular member 2G which snugly nts about the upper reduced portion of the burner screen il and extends above the top surface of the latter to form a short passage 21 at the inlet end of the combustion space 24.

About the hollow body 26 is disposed the lower end of a hollow cylindrical member 28 which bears against the clamping plate I9 and extends upwardly therefrom alongside of the metal shell 22 to the sloping or tapered upper end of the shell. Within the member 2S and forming therewith a part of the refractory wall of the space 2d is disposed a hollow cylindrical member 29. The lower end of the member 29 bears against the top surface of the hollow member 2&5, and the upper end thereof bears against the larger end of an annular member 35i which forms the discharge or outlet end of the combustion space 24. The annular member 30, which projects through the small open end of the outer shell 22, bears against the sloping or tapered part of the shell and at the extreme upper end is provided with a slot forming the restricted outlet 25 for the combustion space 24.

In order to withstand the high temperatures 5 produced in the combustion space 24 during operation of the burner, the hollow member 26, inner cylindrical member 29 and upper annular member r30 may be formed of Aa suitable refractory material, such as beryllium oxide, for ex- 10 ample, having high resistance to thermal shock and possessing rigidity and strength vat `high temperatures. The outer cylindrical member `28 is preferably formed of la refractory material, such as aluminum oxide,.for example, possessing p5 good insulating properties and having adequate strength to serve as the outer portion of the refractory wall. Although not to belimited thereto, the burner screen l1 may be formedof'arrefractory material, suchv as aluminum oxide, for 20 example.

The refractory Wall partsfjust` described may be :secured to one another and within the outer shell '22 Aby a Asuitable high temperature air-hardening cement, as indicatedat 3|, 32,33 yand 34, respec- 125 tively. Such a high temperature 'cement upon hardening provides a rigid and unitary burner structure in which all of the refractory wallparts are effectively` united to form thecombustion space 24. To operate the burner l0 toproduce a high velocity gas stream of heated products of combustion, a combustiblefuel mixture comprising a gaseous fuel and a combustion supporting gas is supplied through the inlet i4 from a .suita'blen35 source of supply. When the burner lis relatively cool and ata low temperature, the: gaseous mixture suppliedthereto passes through-the inlet chamber l2, burner screen I1 andspace 24-from which it isdischarged through the restricted out-Q10 f the .burner -about its may be removablysecuredfat 38,'tothe`. bracket35,

let 25. The combustible gaseousmixture isinitially supplied to ythe burner Vl0 at a` relatively low pressure which may bev equivalent tov a pressure corresponding to about 5 vor 6 inches of water column, for example, so that thefgaseous mixture ".position.

discharged from the space 24 can beignited'to produce and maintain alameat'the outlet. 25.

When a name is being maintained at'y the outlet 25, the pressure of the gaseous mixture supplied to the burner I0 .may bemomentarily.1,50 reduced sufficiently to cause the flame tobackfire through the outlet 25 onto the burner screen l1 in space 24. Whenvthis occurs -a plurality of names are produced and maintained at ytheupper ends of the small apertures I8. 5,55

When the flames are being maintainedwithin the space 24 at the top surface ofthe Iburner screen Il, thepressure of thegaseous mixture supplied to the burner l'may then beincreased. After a short interval of time the llames maintained at the top surface of the 'burner screen I7 4effect such heating ofl theinnery refractory .lining that these surfaces are heated toa highincandescent temperature. The .heating of `the inner refractory lining vto ahighly incandescent conditionA and radiant heat therefrom promotes substantially complete combustion'of the-gaseous .mixture in the combustion space24 before the mixture reaches the outlet 25. From the outlet .25 is discharged a high velocity jet orstream of (70 heated -gases -at altemperat-ure nearlyequal to the temperature in the'cornbustion space 24 and consisting substantially entirely of heatedfproducts of combustion.

.During normal operation the burner l 0 is char- 75 ranging"from.2700a F. to 2900 '-wlien'a` combustible gaseous mixture of air and shell 22,.soI that the Ywith respect Ato the-workfadaptedwto. move into the hightemperature gasrstream. 'fln #accordance with the present` invention, yin order to .position Y'the restricted outlet end of `therefractory .body .f-accuratelyhwithin .the shell .22, the she'llflatthe .narrow 'open-l enol=v thereofisgprovided" #with-ia .pair .ofaspaced apart-locating .ends of the. pins 391 are acterized by the absence of a bright and luminous flame. It is only when the burner is rst started that a llame is momentarily maintained at the elongated slot or outlet 25, as previously explained. After the gaseous mixture has once been ignited, the delivery pressure of the mixture is reduced sufficiently to cause backiiring into the combustion space 24, so thatburning-v of the gaseous mixture will take .place-at ythe top surface of the burner screen I1.

In a burner of the type just described, the heated .products of combustion are discharged A`fro'm"tl'le combustion space 24 through the refstricted'outlet .-25 vat an elevated temperature F. and higher .ordinary gas. such as city gas having a B. t. u. rating of about'550 B. t. u. per cubic foot, for example, is supplied at a pressure in the neighborhood of three pounds per square inch. Under such `operating conditions the .pressure in the .combustionspace 24 may `be'equivalent to la. pres- :sure correspondingfrom 55 to 'Z0-inches offwater Lcolumn and appreciably above that of atmospheric pressure. =The heated. gases are ydischarged fromf'the burner( iat.. an average velocity of about 'Z50/*feet or more perzsecond and at1a maximum velocity of about 1000 feet or more per second.

Burners like theburner |0justidescribed are 0 often employed in machines 'orheating equipment including provisions for .moving and guiding into. the high temperature gas streamswork to Ybe heated. vIn such case each .metal shell-22may be provided with Aa bracket 35 vwhichris formed integrally therewith. V'I-he bracket .'35 .may-'comprise spaced-apart arms havingv aligned: apertures 36 therein 'adapted to zreceiver'a: pin: for-pivotally vmounting the burn-enen a suitable 'support or iixtureiito, position the'b'urner with respectto the To facilitateia'djustment of .pivotal support, .a vpart 31 work `.to..be Lheated.

such part` being-acted.uponinzany suitable mannery to .move Athe burner aboutiitspivotal. support andv hence adjust the .burnerY to 'its work; heating .gated slot. zIn many .heatingeapplicationsf.such

slot-must assumer ax-f'deniterposition `within .the .slot will be properly located elements or pins 39. Thenarrow open` end ofv thev shellZZ `is.formed lWith .shoulderspr :bosses 40 Shaving ropenings ytherein :to .freceivethev ends of :the pins n35. The

firmly anchored; in .posi- :of .the-shell .22, Ias by a press-t,.for example. Asfrbest` shownnin Figs. 2 'and 3,'.the `pins 32E-are paralleLto 'oneV another and extend :across ther ring-shapedvend opening inthe shelly 22 through which the annular mem- 'berf-3 of the refractory body projects.

-The annular membert is formed -withafpair of elongated stra-ightshoulders llll iwhich are spaced apart-.substantially the same'distanceas the pins A39. AThe .straight `sidek portions 42 y of thei refractory` .member` 30 adjacentrtov the shouldersll I t snugly .between-.the pinsl `39, and, lwhen the .refractoryr` body .-is fsnugly disposed Within tion at the 'narrown end the shell 22, the shoulders 4l bear directly against the pins 39 so that the refractory body and restricted outlet 25 will be accurately positioned within the shell 22. With this arrangement the elongated restricted outlet 25 is not only positioned angularly with respect to the shell 22 and bracket 35 thereon but also in a plane transverse to the longitudinal axis of the burner.

The burner l is fabricated by initially uniting the refractory members 26, 28, 29 and 30 together by suitable high temperature air-hardening cement, as explained above, to form the unitary hollow refractory body. After the refractory body is formed in this manner, I apply the air-hardening cement in paste form rto the inner wall surface of the metal shell 22. `After the interior surface of the metal shell is coated with cement, I then slidingly move the refractory body into the shell so that the restricted outlet end thereof passes between the pins 39, as shown most clearly in Fig. 4. The sloping exterior surfaces 43 of the annular member 3D serve to guide the refractory body between the pins 39 to bring the straight side portions 4-2 snugly between the spaced apart locating pins 39 to interlock the refractory body and shell 22. When the shoulders 4| engage the pins 39, excess cement flowing from both ends of the shell 22 is wiped, and thereafter the burner screen `l1 and base member l l and parts associated therewith are secured in position to hold the shoulders 4I against the pins 39.

In this construction it is not necessary to employ a jig or like mechanism to position the hollow refractory body within the outer metal shell 22. Since outer metal shells like the shell 22 often are cast shapes, it is desirable to provide a coating or layer of air-hardening cement at the inner surface of the metal shell to facilitate insertion of the refractory body within the shell and insure a tight lt of these parts. This is so because difficulty is encountered when a relatively tight sliding t must be made directly between the roughened surfaces of a cast metal shell and a refractory body adapted to be positioned therein. It is highly desirable to position the hollow refractory part snugly within the outer shell 22 for the reason that the shell serves to hold'the refractory body together even' when cracking of the refractory walls occurs upon repeatedly heating the refractory body to high elevated temperatures.

It will thus be seen that I have provided an improved burner in which the outer shell and inner refractory hollow body are utilized to facilitate positioning the refractory body in a deiinite position with respect to the outer shell. Moreover, a simple fabricated construction is obtained in which the hollow refractory body can be readily replaced even in the eld, when this becomes necessary, without the use of special tools, thereby producing an inexpensive and easily manufactured construction.

Although I have illustrated and described a particular embodiment of my invention, I do not wish to be limited to the particular arrangement set forth, and I intend in the following claims to cover all modifications which do not depart from the spirit and scope of my invention.

What is claimed is:

l. A gas burner comprising a metal shell having an opening in a wall thereof, a hollow body in said shell which provides a substantially closed combustion chamber having an inlet for a combustible gaseous mixture and a restricted outlet for high temperature heating gases, said body being disposed in said shell so that the restricted outlet end of said body projects through and beyond said opening and high temperature heating gases adapted to issue from the restricted outlet avoid contacting said shell, said body at the restricted outlet end thereof having a pair of substantially straight shoulders in spaced apart parallel relationship at the exterior surface thereof, and a pair of spaced apart parallel pins xed to said shell at said opening and extending across the latter, a portion of the restricted outlet end of said body extending into the space between said pins so that said shoulders engage and contact said pins to locate the restricted outlet in a definite position with respect to said shell.

2. A gas burner having a metallic shell provided with an opening in one end thereof and a bracket projecting from its outer surface, a hollow refractory structure forming a combustion chamber received by said shell, said structure being provided with an inlet for a fuel mixture at one end and an elongated outlet at the other end, said outlet extending through the opening in said shell, a pair of parallel locating pins mounted in said shell and extending across said opening, said pins being spaced far enough apart to receive said elongated outlet between them, and said structure being formed with surfaces to be engaged by said pins to locate said structure with respect to said shell whereby said elongated outlet will be located at a denite angular position with respect to said bracket.

ALFONS A. FURCZYK.

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

UNITED STATES PATENTS Number Name Date 997,278 Donnelly July 11, 1911 2,367,119 Hess Jan. 9, 1945 2,489,244 Stalego Nov. 22, 1949

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