US2610675A - Flame retaining atmospheric gas burner - Google Patents

Description

P 1952 E. R. DOWNE 2,610,675

FLAME RETAINING ATMOSPHERIC GAS BURNER Filed NOV. 16, 1950 2 Sl'lEETS--SHEET l IN V EN TOR.

50144420 9. DOW/V6 Sept. 16, 1952 E. R. DOWNE 2,610,675

FLAME RETAINING ATMOSPHERIC GAS BURNER Filed Nov. 16, 1950 2 swam-41mm 2 1N VEN TOR. EDWARL B. 0 WNE Patented Sept. 16, 1952 FLAME RETAINING ATMOSPHERIC GAS BURNER Edward R; Downe, Elyria, Ohio, assignor to The C. A. Olsen Manufacturing Company, Elyria, Ohio, a corporation of Ohio Application November 16, 1950, Serial No. 196,016

1 This invention relates to gas burners and more particularly to those known as atmospheric, wherein a primary mixture of gas fuel in insufficient air for complete combustion emerges from the burner mouth, and combustion takes place beyond the mouth in the surrounding atmosphere from which sufiicient additional air is had for completion of combustion.

More particularly this invention relates to such atmospheric burners, of the specific type known as single port, self-piloting, flame-retention, character, wherein the primary mixture has dis- 4 Claims. (01. 158-114) charge in a Single principal and relatively large stream, through a head having a mouth about which means are provided for piloting the main steam at low turn-down and for retaining the flame of the main stream on high turn-up.

The invention is thus directed to the discharge or head end portions of an atmospheric gas burner, and objects of the invention are, briefly, to provide a burner having the specific characteristics described, of superior operation, and extremely simple and inexpensive construction.

As will hereinafter appear, the invention contemplates employment of what is known as a ribbon type of construction in attaining the above objects. Also as is Well understood in the art, a flame spreader is often employed in connection with the type of burner contemplated, the spreader being located in spaced opposite relation to the mouth of the burner head.

Other objects of the invention are to attain a construction wherein all parts and particularly the ribbon parts ofthe burner head are positively located with respect to each other. and means are provided by the same construction, for mounting of a stem for support of a flame spreader where its use is desired.

In a burner of the class described and particularly where a flame spreader is employed in connection therewith, it is important that flow of the fuel mixture to the burner head has uniform velocity distribution about the head; but also it is usually necessary that the supply tube for the burner head include a portion curved through asubstantial bend. A further object of the invention is to attain equalized flow to the head, notwithstanding such bend, by novel bafiie means as will appear.

Further objects and advanta es will be apparent from the following description taken in conner-tion with the accompanying drawings, wherein:

Fig. 1 is a view general y in t pical sectional elevation showing p rtinent portions of a burner embodying the invention;

Fig. 2 is a transverse section as in the plane of line 22, Fig. 1;

Fig. 3 is a positive detail of a ribbon part employed in the burner head assembly;

Figs. 4, 5 and 6 are details of the burner head illustrated in Fig. 1, Fig. 4 being a plan view, Fig. 5 being a View similar to Fig. 4 but with certain parts removed, and Fig. 6 being a sectional elevation as in the plane of line 66, Fig. 4;

Fig; '7 indicates a modified construction, illustrating the same principally in sectional elevation; and

Fig. 8 is a transverse section as in the line 8--8 of Fig. 7.

With reference now to, the drawings and first to Figs. 1 to 6 thereof, the burnerillustrated includes a generally tubular member I, of circular section throughout its length, the member 1 including an enlarged head portion A, a straight portion B leading upwardly to the head portion, and a curved portion C leading tangentially to the portion B from a horizontal portion through which a primary mixture of gas and air is had. As here indicated, the curved portion C is arcuate about a center 0, through as is usual in the gas furnace art.

As illustrated the enlarged head portion A of the member I provides an interior annular shoulder ab.

According to this invention a spider 2 is located within the head portion A, having its legs seating against the shoulder ab, and extending therefrom substantially short of the mouth at the upper extremity of the head. As here indicated the spider 2 ha three legs 2a extending radially from a central cylindrical hub portion 2b; and is formed of three strips of metal welded together at their leg portions.

The hub portion 2?; is thus adapted to receive and position a cylindrical stem 3, as indicated Fig. 1, having a cross pin 3a, for supporting a flame spreader, not illustrated.

Further according to this invention there is arranged within the head portion A above the spider 2, a circular band 4 having corrugations running longitudinally of the discharge portions A and B of the member I, and a plain generally cyl ndrical band 5 is positioned immediately within the circular band 4.

The corrugated circular band 4 may be formed of a strip of transversely corru ated metal ,ribbon as indicated Fig. 3 and fits closely within the mouth o the head portion A: and the cylindrieal hand 5 fits tightlv ithin t e band 4.

Pre erably for such fit and as illustrated particularly at 45, Fig. 4, the circular band 4' has its ends slightly spaced from each other and the cylindrical band has out-turned ends abutting each other and disposed between the circular band end.

The bands 4 and 5 are of the same width, being such that they are flush with the top or mouth of the head portion A and abut the legs 20*. of the spider 2. Thus the spider positively locates both bands, while the latter secure the spider in abutting relation to the shoulder ab.

The parts are so proportioned that the inner diameter of the inner band 5 is the same as that of the straight portion B of the tube I so that a generally annular cavity a is provided, longitudinally located between the shoulder ab and the bands 4 and 5, in free communication with the principal passageway of flow through the portions a and b of the burner, extending peripherally about such principal passageway.

The corrugated of the band 4, in cooperation with their immediately associated parts, provide a circle of ports leading from the cavity a, immediately surrounding the principal discharge mouth opening of the inner band 5.

In operation, most of the primary mixture will emerge from the burner through the inner band 5 as a solid column and its combustion eventually will be completed, with additional secondary air from the surrounding atmosphere above the burner and about the column.

However, a slight peripheral portion of the flowing primary mixture will enter the cavity a, expanding thereinto and emerging through the ports at the interstices of the corrugated ring 4, at a substantially lower velocity than that of the main central stream. Combustion of the mixture from such ring of small ports will be characterized by taking place immediately adjacent their mouths, without blow-01f therefrom, and also without backfire therethrough, these ports being sufficiently small in area and great in length, for the purpose. It may be observed that the construction specifically illustrated and described provides a double row of pilot gas ports, one on each side of the circular band 4, within the corrugations thereof. On some gases it is possible to dispense with the inner, cylindrical band 5, thus providing a single row only,

of ports, between the corrugated band 4 and the head portion A thereabout.

Thus the burner will operate through a wide range of capacity, the ring of small flames piloting the main flame therewithin, to prevent outage on low operation and blow-off on high operation.

The above described operation is dependent somewhat on uniformity of flow as received at the head portion A from the straight portion B.

To provide such uniformity, particularly where the straight portion B is short and the curved portion C is of short radius or extends through a large angle, I provide a bafile 6 within the member l, disposed in the plane at which the straight and curved portions B and C join each other, as indicated by the broken line D.

The baiile 6 extends in said plane, from the radially outermost tube wall portion with respect to the curvature of the curved portion C, toward the radially innermost tube wall portion with respect to such curvature. In the plane D the baflle has curved contour as, indicated in Fig. 2, arcuate about a center f located at the inner wall of the tube, in the general central plane common to both the curved and straight tube portions C and B-such being the plane of sectioning of Fig. 1 in the drawings. The arrow H in Fig. 2 indicates the radius of the contour of the baflle 6.

In the construction thus far described, the tube member I has been considered as formed of a casting such as iron, with the head portion A integral with its other portions.

With reference now to Figs. '7 and 8, a construction is indicated wherein the tube portion It) may be of sheet metal and only the head portion Illa a casting.

Such casting at its lower portion is adapted to receive and fit its tube portion ID, with an internal flange ll overlying the end of the tube l0 and a dependent flange I2 extending thereabout. Above the flange II a casting Illa is formed as indicated in Figs. 1 and 6, to receive the same parts in the same manner as previously described. A baffle 16 may be provided in the tube [0 at the joinder at its straight and curved portions and corresponding with the bafiie 6 previously described, by creasing the sheet metal of the tube In as indicated in Figs. 7 and 8.

What I claim is:

1. In a burner of the class described: a straight tubular discharge portion having at its end a head portion there providing an enlarged discharge mouth for the passageway through said discharge portion, with a shoulder at the enlargement, a circular band fitting within said head portion to extend from the downstream extremity thereof short of said shoulder, and having corrugations running longitudinally of said discharge portion, and a cylindrical band fitting within said corrugated band, said circular band having ends slightly spaced from each other, and said cylindrical band having outturned ends abutting each other and disposed between said circular band ends.

2. In a burner of the class described: a straight tubular discharge portion having at its end a head portion there providing an enlarged discharge mouth for the passageway through said discharge portion, with a shoulder at the enlargement, a circular band fitting within said head portion to extend from the downstream extremity thereof short of said shoulder, and having corrugations running longitudinally of said discharge portion, and spider means having legs resting on said shoulder and locating said band in spaced relation therefrom.

3. In a burner of the class described: a straight tubular discharge portion having at its end a head portion there providing an enlarged discharge mouth for the passageway through said discharge portion, with a shoulder at the enlargement, a circular band fitting within said head portion to extend from the downstream extremity thereof short of said shoulder, and having corrugations running longitudinally of said discharge portion, spider means having legs resting on said shoulder and locating said band in spaced relation therefrom, said spider means including a hub portion having an opening, and a flame spreader stem mounted in said opening.

4. In gas burner means of the class described and including burner head means and a supply tube therefor, said supply tube including a curved portion and a straight portion leading tangentially from said curved portion upwardly to said head means, both said portions being of circular section; means for equalizing flow through said tube to said burner head means, and comprising a baflie within said tube disposed in the plane at which said straight and curved portions join each other, and extending in said plane, from the radially outermost tube wall portion with respect to the curvature of said curved portion, toward the radially innermost tube wall portion with respect to said curvature, said bafiie having a curved contour in said plane, arcuate about a center located at the inner wall of said tube, in the general central plane common to said curved and straight tube portions.

EDWARD R. DOWNE.

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

UNITED STATES PATENTS Number Name Date 791,923 Machlet June 6, 1905 1,407,346 Cain Feb. 21, 1922 2,237,889

Rickert Apr. 8, 1941

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