US2987119A - Flame spreaders - Google Patents

Description

J. T. ALGER FLAME SPREADERS June 6, 1961 5 Sheets-Sheet 1 Filed Oct. 28, 1957 FIG. 1

INVENTOR. 'Jrry 77191967 BY WM i/z YM I n7 dgiarneqs June 6, 1961 3 Sheets-Sheet 2 Filed Oct. 28, 1957 .P s 9 2 m M w W .a E w d. J v M M w V w M M @Q a United States Patent 2,987,119 FLAME SPREADERS Jerry T. Alger, Chicago, Ill., assignor, by mesnc assignments, to Configured Tube Products (30., St. Louis, Mo., a corporation of Missouri Filed Oct. 28, 1957, Ser. No. 692,824 3 Claims. (Cl. 158-113) This invention relates to flame deflectors or spreaders for use on burners adapted to consume gaseous fuel.

One object of the present invention is to provide a new and improved flame spreader that will produce an extremely wide, flat, downwardly inclined flame, of a type well adapted for use in water heaters and other gas appliances.

A further object is to provide a new and improved flame spreader which is so arranged that the flame will not readily flash back or blow out.

Further objects and advantages of the present invention will appear from the following description, taken with the accompanying drawings, in which:

FIG. 1 is a small-scale side elevational view of a water heater burner equipped with a flame spreader that will be described as an illustrative embodiment of the present invention.

FIG. 2 is a bottom view of the burner and flame spreader, taken generally as indicated by the line 2-2 in FIG. 1.

FIG. 3 is an elevational sectional view, taken generally along the line 3-3 in Fig. 2.

FIGS. 4 and 5 are top and bottom plan views of the flame spreader.

FIG. 6 is a side elevational view of the flame spreader.

FIG. 7 is an end view, showing the inner end of the flame spreader.

FIG. 8 is a plan view of a modified flame spreader.

FIG. 9 is a side elevatioual view of the flame spreader of Fig. 8.

FIG. 10 is a front elevational view showing the flame spreader of FIG. 8.

FIG. 11 is a fragmentary enlarged sectional view, taken generally along a line 1111 in Fig. 8.

FIG. 12 is a transverse sectional view, taken along a line 1212 in FIG. 11.

FIG. 13 is a plan view showing a flame spreader which is somewhat modified with respect to the flame spreader of Figs. 8-12.

FIG. 14 is a side elevational view showing the flame spreader of FIG. 12.

As already indicated, FIG. 1 shows an application of the invention to a water heater 10, having a burner 12 equipped with a flame spreader 14. The burner 12 may be of a known type having a mixture tube 16 which discharges a mixture of gas and air in a horizontal direction. In the illustrated application, the mixture tube 16 is bent into the form of an elbow, for the sake of compactness. Thus, the mixture tube 16 has an entrance portion 18 which is vertical, and an exit or discharge portion 20 which is horizontal. An axially directed discharge port 22 is formed in the end of the discharge portion 20. It will be seen that the mixture tube 16 is turned inwardly around the discharge port 22 so as to form an inturned annular flange 24.

In this case, the water heater 10 is in the form of a tank having a cylindrical sidewall 26. A bottom wall 28 is mounted across the lower portion of the sidewall 26 but is spaced upwardly from the lower end of the sidewall so as to form a chamber 30 for the burner 12. A stack or flue pipe 32 extends upwardly through the water heater 10 and communicates with the burner chamber 30. It will be seen that the burner 12 is positioned at one side of the burner chamber 31) and is ice adapted to provide a flame 31 which extends to the other side of the chamber and then sweeps upwardly along the bottom wall 28. The flame doubles back along the bottom wall toward the burner and then passes upwardly into the flue pipe 32. It will be seen that the flue pipe 32 is off center and is on the same side of the water heater as the burner 12.

In order to produce this flame pattern, the flame spreader 14 is provided with lower and upper bowls 34 and 36. It will be seen that the lower bowl 34- is upright in position on concave upwardly. It will be seen that the illustrated bowl 34 is spherically curved and is somewhat less than hemispherical in extent. However, the shape of the lower bowl 34 may be varied considerably in order to change the pattern of the flame 31. One edge portion of the bowl 34 is formed into a generally semi-cylindrical mounting stub 38 which fits around the lower portion of the mixture tube 16 at its outer end, as clearly shown in FIGS. 3 and 5. The mounting portion 38 may be welded, clamped or otherwise secured to the mixture tube 16. Horizontal flanges 40 extend laterally from the upper edges of the semi-cylindrical mounting stub 38.

From FIG. 3 it will be apparent that the edge portion of the lower bowl 34 opposite from the mounting stub 38 extends upwardly into the path of the combustible mixture discharged from the mixture tube 16. The upper margin of the lower bowl 34 is approximately at the level of the axis of the burner tube 16. It will be seen that the upper margin of the bowl 34 is rounded upwardly into a horizontal flange or lip 42. The effect of the lower bowl 34 is to deflect the combustible mixture upwardly into the upper bowl 36.

As illustrated, the upper bowl 36 is considerably larger in diameter and somewhat flatter than the lower bowl 34. It will be seen that the upper bowl 36 is inverted in position or is concave downwardly. In the illustrated arrangement, the upper bowl is spherically curved but is quite flat and constitutes much less than a hemisphere.

As in the case of the lower bowl 34, the upper bowl 36 has one edge portion formed into a generally semi-cylindrical mounting stub 44 which fits over the upper portion of the mixture tube 16 at its outer end. Horizontal flanges 46 may be formed at the lower edges of the mounting stub 44 and may be arranged to abut against the corresponding flanges 411 on the lower bowl 34. The flanges 4t) and 46 may be welded or otherwise secured together.

The lower margin of the upper bowl 36 extends downwardly into the path of the mixture discharged from the mixture tube 16. The level of the lower margin on the upper bowl 36 is approximately the same as that of the upper margin on the lower bowl 34. An outwardly extending horizontal flange 48 is provided around the lower margin of the upward bowl 36. Due to its greater extent, the upper bowl 36 extends outwardly from the burner tube 16 a considerably greater distance than the lower bowl 3 4.

Thus, the combustible mixture deflected upwardly by the lower bowl 34 is deflected downwardly and spread laterally by the upper bowl 36. The result is the wide, flat, downwardly inclined flame 31 shown in FIGS. 1 and 2. The flame pattern may be changed by varying the shape of the bowls 34 and 36. Thus, the size and curvature of the bowls may be changed to vary the size and shape of the flame. Moreover, the bowls may be made oblong rather than circular, and otherwise may be varied in shape.

It will be seen that the marginal portions of the lower and upper bowls 34 and 36 are generally aligned with each other adjacent to the mounting stubs 38 and 44. The burner tube 16 is received between the mounting stubs so as to project part way into the bowls from the margins thereof. The opposite margin of the upper bowl extends considerably beyond the opposite margin of the lower bowl.

In addition to deflecting the main part of the fuelai-r mixture upwardly into the upper bowl, the lower bowl directs a small part of the mixture laterally to form small lateral retaining flames which stabilize the main flame. Thus, the action of the flame spreader is to protect the main flame from flashing back or blowing out.

The flame spreader is well adapted for use in applications where there is a natural draft, as shown in FIG. 1, or where a forced draft is utilized to blow the outer end of the flame through a heat exchanger or the like.

FIGS. 842 illustrate a modified flame spreader 60 which also has upper and lower flame-shaping bowls 62 and 64. However, the bowls 62 and 64 are of somewhat different shape than the bowls employed in the flame spreader of FIGS. 1-7. As before, the upper bowl 62 is concave downwardly, and the lower bowl 64 is concave upwardly, but the shape of each bowl is similar to that of a shallow rounded shovel or scoop.

The upper bowl 62 has a main or upper wall portion 63 which is concave downwardly and of a shallow, approximately frusto-conical curvature. From FIG. 9, it will be seen that the concave wall portion 63 has a lower margin 65 which is substantially in a horizontal plane. In this case, the margin 63 has a rounded front portion 66 (FIG. 8) and a pair of angularly related side portions '67. Along the margin 65, the curved wall 63 is formed into a substantially flat horizontal flange 68.

Similarly, the lower bowl 65 has a main or lower wall portion 69 which is concave upwardly and of a shallow, approximately frusto-conical curvature. The curved wall 64 is provided with an upper margin 70 which is substantially in a horizontal plane. From FIG. 8, it will be seen that the margin 70 has a rounded front portion 71 and a pair of angularly related side portions 72. Along the margin 70, the lower bowl 64 is formed with a flange 73 which is turned downwardly at an acute angle. The lower margin 65 of the upper bowl 62 and the upper margin 70 of the lower bowl 64 are in substantially thesame horizontal plane, but the upper bowl extends outwardly to a substantial extent beyond the lower bowl, to define a slot or opening '74 through which the flame escapes.

As shown to best advantage in FIGS. 9 and 11, the flow of secondary air along the outer surfaces of the upper and lower bowls 62. and 64 is controlled by upper and lower flanges or baflles 75 and 77 which are mounted thereon. The flanges 75 and 77 extend along the margins 65 and 70 and are spaced back from the marginal flanges 68 and 73. It will be seen that the upper flange 75 is turned upwardly, while the lower flange 77 is turned downwardly. The flanges 75 and '77 may be welded or otherwise secured to the upper and lower bowls 62 and 64.

The flanges 75 and 77 deflect the secondary air upwardly and downwardly from the margins 65 and 70 of the upper and lower bowls. In this way, the flanges 75 and 77 prevent any streams of high velocity secondary air from striking the base of the flame adjacent the margins 65 and 7G. Were it not for the flanges or baflles 75 and 77, such high velocity air streams might tend to lift or tear the flame away from the margins of the bowls 62 and 64, in which case the burner would operate in a somewhat unstable, noisy manner.

The rear end portions of the upper and lower bowls 62 and 64 are formed into opposite semicylindrical mounting stubs '76 and 73 with opposed horizontal wings or flanges 80 and 82 extending outwardly therefrom. The upper and lower flanges or wings 80 and 82 may be welded or otherwise secured togethe In the illustrated construction, welds are indicated at 84. The opposed semicylindrical stubs 76 and 78 are adapted to be mounted around the front end of a burner tube 86. The extreme rear ends of the wings 80 on the upper bowl 62 4 are formed into mounting brackets 88 whereby the flame spreader and the burner tube may be mounted on a suitable support (not shown).

The curved upper and lower walls 63 and are connected to the wings and 82 by steeply sloping, generally triangular walls 90 and 92 which close the rear end of the cavity between the bowls and prevent rearward escape of the combustible mixture. Thus, the combustible mixture fans outwardly to form a short broad flame 94, as indicated by the flame patterns shown in FIGS. 8 and 9. After being directed upwardly into the upper bowl 62 by the lower bowl 64, the combustible mixture is directed downwardly by the upper bowl, so that the merging flame is downwardly directed at a small angle. Of course, the heat of the flame causes the flame to be swept upwardly as it fans outwardly.

In the construction of FIGS. 8-12, the short, wide character of the flame is made more pronounced by providing a deflecting member 98 within the cavity between the bowls 62 and 64. As illustrated, the deflecting member d8 has a pair of generally vertical flanges 100 which are symmetrically disposed on opposite sides of the burner axis and are arranged to diverge from each other in a forward direction. The flanges 100 are joined at one end by a web 102 which may be welded or otherwise secured to one of the bowls, preferably the upper bowl 62, as shown. In this case, each of the vertical flanges 10% has a lower edge 104 which is spaced upwardly a short distance from the lower bowl 64. The diverging flanges 100 have the effect of spreading the combustible mixture outwardly so as to broaden and shorten the flame. This will be apparent from a comparison of FIG. 8 with FIG. 13, which shows a modifled flame spreader in which the deflecting member 98 is omitted. Otherwise, the flame spreader 110 is the same as the flame spreader 60 of FIGS. 8-l2. It will he observed that the flame spreader 110 produces a flame 112 which is somewhat longer and narrower than the flame 94 produced by the flame spreader 60. Either the flame spreader 60 or the flame spreader 110 may be employed in various situations depending upon the desired shape of the flame.

The flame spreaders of FIGS. 8-14 may be employed very advantageously in water heaters, driers and other appliances for which a broad, flat, short flame is desired. It has been found that the spreaders produce a highly stable flame which will resist blowing out and flashing back even in a forced draft of air.

I claim:

1. A flame spreader comprising: an inverted shallow upper bowl; an upright shallow lower bowl of lesser horizontal extent than said upper bowl, said lower bowl having upper rearward edge portions thereof engaging lower rearward edge portions on said upper bowl along a substantially horizontal plane, each of said bowls having curved edge portions extending along said plane forwardly from said engaging edge portions to form an unobstructed continuous curved rim for each bowl, each of said rims lying along said plane throughout substantially its entire extent, the rim on said lower bowl being spaced inwardly from the rim on said upper bowl so as to provide a downwardly discharging crescent-shaped outlet from the hollow body formed by said opposed engaging bowls; an integral inverted trough-shaped stub communicating with the interior of said upper bowl and extending rearwardly from rearward portions of said upper bowl; an integral upright trough-shaped stub communicating with the interior of said lower bowl and extending rearwardly from rearward portions of said lower bowl, and having edge portions engaging with edge portions on said inverted stub along said plane so as to form a tubular mounting means whereby said flame spreader is adapted for mounting on a complementary burner tube having an axial discharge port; and means for joining the two stub portions together.

2. The combination of claim 1 including an outwardly inclined baffle flange mounted on forward exterior portions of at least one of said bowls, said flange being disposed slightly inwardly of, substantially coextensive with, and parallel to the unobstructed rim of the bowl upon which said flange is mounted, said flange adapted to divert secondary air away from the last-mentioned rim.

3. A flame spreader comprising: an inverted shallow upper bowl; an upright shallow lower bowl of lesser horizontal extent than said upper bowl, said lower bowl having upper rearward edge portions thereof engaging lower rearward edge portions on said upper bowl along a substantially horizontal plane, each of said bowls having curved edge portions extending along said plane forwardly from said engaging edge portions to form an unobstructed continuous curved rim for each bowl, each of said rims lying along said plane throughout substantially its entire extent, the rim on said lower bowl being spaced inwardly from the rim on said upper bowl so as to provide a downwardly discharging crescent-shaped outlet 20 from the hollow body formed by said opposed engaging bowls; means on said upper bowl forming a semicircular opening in said rearward edge portion thereof and communicating with the interior of said upper bowl; and means on said lower bowl forming a semicircular opening in said rearward edge porton thereof and communieating with the interior of said lower bowl; said semicircular openings being opposite each other to form a circular opening communicating with the interior of said hollow body and adapted to receive a complementary burner tube having an axial discharge port.

References Cited in the file of this patent UNITED STATES PATENTS 1,285,665 Franklin Nov. 29, 1918 1,518,223 Schott et al. Dec. 9, 1924 1,707,451 Thomas et a1. Apr. 2, 1929 2,588,759 Poschadel Mar. 11, 1952 2,766,819 Little Oct. 16, 1956 2,867,272 Morrison Jan. 6, 1959

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