US3825398A

US3825398A - Plural rate burner with flame enhancement

Info

Publication number: US3825398A
Application number: US00370494A
Authority: US
Inventors: J Katchka; F Hendrick; M Egger
Original assignee: Robertshaw Controls Co
Current assignee: Robertshaw Controls Co
Priority date: 1973-06-15
Filing date: 1973-06-15
Publication date: 1974-07-23
Anticipated expiration: 1991-07-23

Abstract

A burner produces an outward extending flame at a high rate and an upward extending flame at a low rate. Facilities are provided for enhancing the entrainment of air in both the outward extending flame and the upward extending flame.

Description

United States Patent Katchka et al.

[ July '23, 1974 PLURAL RATE BURNER WITH FLAME ENHANCEMENT Inventors: Jay R. Katchka, Cypress; Fred W.

Hendrick; Michael E. Egger, both of Long Beach, all of Calif.

Robertshaw Controls Company, Richmond, Va.

Filed: June 15, 1973 Appl. No.: 370,494

Assignee:

References Cited UNITED STATES PATENTS 12/1957 Beck 431/80 X 3,405,999 10/1968 Riehl 431/285 X 3,516,773 6/1970 Rosenberg et a1. 431/284 3,561,901 2/1971 Jackson et a1. 431/284 3,754,853 8/1973 Katchka et a1 431/285 Primary Examiner-Edward G. Favors Attorney, Agent, or FirmAnthony A. OBrien [5 7] ABSTRACT A burner produces an outward extending flame at a high rate and an upward extending flame at a low rate.

Facilities are provided for enhancing the entrainment of air in both the outward extending flame and the upward extending flame.

8 Claims, 6 Drawing Figures i 48 r, v r

I so 1 PATENTED M2319" 3, 825. 398

sum 10F 2 FIG. I

FIG. 2

' i (I 60 2 5e 58 42\ 62 72 I 48 I3 i 22 PATENTEU -2 74 SHEET 20F 2 BACKGROUND OF THE INVENTION 1. Field of the Invention 1 The invention relates to burners for gaseous fuel and in particular to burners for operating at more than one rate. I I

2. Description of the Prior Art There are number of prior art burners, as exemplified by U.S. Pat. No;'3,405,999, which-can be operated at more than one rate. Prior art plural rate burners produce acceptable flames when burning natural gas; however, some burners have not provided suitable blue flames when burning propane gas, or the like, due to the higher BTU per cubic foot content of propane gas and the higher proportional air mix requirement;

SUMMARY OF THE INVENTION The invention is summarized in that a burner for operating at both low and high rates includes a burner member having an inlet for receiving gas and a port for projecting gas in a first direction such that during a high rate of ope ration a high rate flame extending for at least a predetermined distance along the first direction is produced and during a low rate of operation a low rate flame deviating from the first direction in less than said predetermined distance to a second direction transverseto the first direction is produced, a first spreader spaced in the first direction from the burner member in the path of the high rate flame for enhancing-the buming of the gas in the high rate flame, a second spreader spaced in the second direction from the port and having an Opening for allowing passage of the low rate flame, and means disposed within the opening fordispersing the low rate flame to enhance the burning of the ga'sin the low rate flame. H

An object of the invention is the construction of a plural rate burner having enhanced flame characteristics at a low rate of operation. v I

Another object of the invention is to providea plural rate burner suitable for operation on high-heatgenerating-capacity gaseous fuels, such as propane gas.

tion will become apparent from the following description of the preferred embodiment with the drawings. e 4

' BRIEF DESCRIPTION OF TI-IE DRAWINGS: FIG. l.is a elevation view in cross section of a burner apparatus in accordance with the invention and illustrating a low rateof operation.

FIG. 2 is a elevation view with parts broken away il taken in conjunction lustrating a high rate operation of the burner apparatus shown in FIG, 1. I 1

FIG. 3 is a top view of a lower'flame spreader burner apparatus shown in FIGS. 1 and 2. r

no. 4 is a perspective view, partially brokerifaway of the lower flame spreader'shown in FIG; 3. FIG. 5 is atop view of an upper flame spreader of the bumer apparatus shown in FIGS. 1 and 2.

FIG. 6 is a perspective view spreader'shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT.

of the upper flame rate gaseous supply facilities (not shown) such as the fuel control device disclosedin U.S. Pat. application Ser. No. 98,246 by Jay R..- Katchka and Henry C. Braucksiek filed on Dec. 15, .1970, now US. Pat. No. 3,762,639, issued Oct..2,,l973.

The annular burner member 16 has an outer tubular section 12 and an inner tubular'section 14 which form an'annular chamber' IS. The

tubular sections

12 and 14 are coaxial with the upper ends joined and with a lower flanged portion20 of the inner tubular section joined to the lower end of the outer tubular section 12.- A fitting 22-is secured within an opening 24 in the outer tubular section 12 to form an inlet to the chamber 18. A plurality of circumferentially-spaced and outwardfacing burner ports 26 are formed in the outer tubular section 12 while a single inward and upward directed burner port 28 is formed in a deformed portion 30 of the inner tubular section 14. Theouter tubular section 12 is generally conical so that the annular chamber 18 is gradually reduced in cross section toward the upper end. T The tubular support 32 is suitably secured to a bottom plate 34 attached to the annular burner member 16 and has upper slotted spring portions 36 with dimples 38 mating with a groove 40 in the flame sensing element 42. The'element 42 is supported along a vertical axisf of the annular burner member 16 and extends above the annular burner member 16 such that upward extending flames from the ports 26 curving inward 5 ofthe' above the annular'member 16 impinge upon the element 42. The flame sensing element is any suitable thermo-responsive device, such as a thermocouple, which can be used to operate safetyfacilities, such as a magnetic safety valve (not shown), to prevent release of hazardous gas in the event that the flame of the burner is extinguished by air drafts, loss of fuel, etc. Openings 44 are formed-in'the bottom plate 34 and are sufficiently sized to supply adequate air for mixing with gas from the port-28.

The lower "flame spreader 13, shown in FIGS. 3 and 4, has downward bent leg portions 46 extending from an upward flaring frusto-cone portion 48. Tabs 50 are provided on the leg portions 46and are attached, as iI- lustrate'd in FIG. 2, to the outer tubular. section 12 below the ports 26, so that the frusto-cone portion 48 is in the path of gas flames extending outwardly from the burner ports 26. An opening 52 between the ftUStO cone portion 48 and the outer tubular section 12 is sufficiently large to supply-adequate air for mixing with gasfrom the ports 26.

The upper flame spreader 1s, shown-in FIGS; Sand 6, has an annular plate-like portion 56I'connected by spokes 5 8 to a collar 60 which is attached to the outer tubular section 12 above the burner ports 26, as illustrated in FIG. 2, so that the plate-like portion 56 is disposed above thepath of gas flames extending outward 64 with enlarged head portions'66 extend inward from the annularportion 56 into the openings 62. I

The shield 70 is frustro-conically" formed'and is secured to the upper flame spreader 15 by outward bent tabs 72 extending through the openings 62. A-spa'ced with propane to lproduce acceptable blue flames from propane gas. At the low rate of operation,

top 74 is bent horizontally from an upward extending leg76 of the shield 70 and secured in position-by inwardlybent tabs 78from upward extending legs 80 from'the shield 70; a

The operation of theplural rate burner at a low rate is illustrated in FIG. 1. With a relatively low pressure gaseous fuel supplied to the inlet fitting 22 and chamberl8 of theannul'anburner member 16, flames'sustained by fuel exiting through ports '26 extendupward through the openings 62 in the upper spreader member 15. The tabs 64 and head portions 66, shown in FIGS. 5 and 6, disperse the upward extending flames to enhance the entrainment of air with the burning fuel and to eliminate yellow flames and produce acceptable blue flames. The low rateflames passing through the openings 62 converge inward over the top of the annular burner- 16 toward the axis of ithe annular burner member 16 to impinge upon the flame sensing element 42. The shield 70 protects the low rate flames from being extinguished by a draft :of air or.0ther similar disturbance. The spacing of the'top 74 from the shield 70 by the

legs

76 and 80 provides adequate ventilation for the flame inpingingupon the sensing element 42.

At the high rate of operation illustrated in FIG. 2, the pressure of the fuel within the annular burner member 116 is sufficient to direct flames in a generally horizontal direction outward from the ports 26 against the frustoconical portion 48 of the'lower flamespreader 48. Initially, the outward extending flame is-confined below the plate-like portion 56 of the upper flame spreader ber 16 supplies air for the high rate flames. The frustoconical portion 48 spreads and disperses the burning fuel in the outward extending flames and enhances the mixtureof fuel with airto improve combustion.

Also at the high rate of operation, flame from the burner port 28 impinges on the flame sensing element 42 to maintain the element 42 in its operated condition. At the low rate of operation, the flame generated by the burner port 28 is insignificant relative to the flame from the much larger and more numerous 'ports 26. and hence is not illustrated in FIG. I.--

on particular advantage of the burner apparatus is that it can be employed in a system utilizing liquid propane gas. Propane gas has a much higher BTU per cubic foot content than commonly used natural gas. At the high rate of operation, the frusto-conical portion 48 in the path of the outward extending flame together with the opening 52 supplying air produce sufficient air the, tabs 64 and head portions 66 extending into the openings62 together with the supplyof air from the opening 52 provide adequate mixing of air with the low rate flame to produce blue flames. Thus, the yellow flames normally associated with the standby or low rate operation ofnon-aerated burners for propane gas is eliminated.

Since many variations, modifications and changes in detail can be made to the present embodiment, it is intended that allmatter contained in the foregoing description'or'sh'own on the accompanying drawings shall be interrupted as illustrative and not in a limiting sense.

Whatis claimed is: 1. A burner apparatus for operating at both low and high rates comprising i a burner member having an inlet for receiving gaseous fuel and a port for'projecting non-aerated gaseous fuel in afirst'direction such that during a high rate of operation a high rate flame extending for at least a predetermined distance along the first direction is produced and during a low rate of operation for enhancing the burning of the gaseous fuel in the "high rate flame,

a second spreader spaced in the second direction from the port and having an opening for allowing vpassage of the low rate flame, and

means disposed within the opening for. dispersing the low-rate flame to enhance the burning of the gaseous fuelin the low rate flame.

2. A burner apparatus for operating at both low and high rates comprising i a burner member'having an inlet for receiving gas and a port for projecting gas in a first direction such that during a high rate of operation a high rate flameextending for at least a predetermined distance along the first direction is produced and during a low rate of operation a low rate flame deviating from the first direction in less than said prede- 1 termined distanceto a second direction transverse to the first direction is produced, a first spreader spaced in the first direction from the burner member in the path of the high rate flame from the port and having an opening for allowing in the path of the low rate a burner member having an inlet for receiving gas and a plurality of spaced ports for projecting gas in a substantially horizontal direction such that during a high rate of operation a high rate flame extending for at least a predetermined distance along the horizontal direction is produced and during a low rate of operation an upward extending flame deviating from the horizontal direction in less than said predetermined distance is produced,

a first spreader spaced in the horizontal direction from the burner member in the path of the high rate flame for enhancing the burning of the gas in the high rate flame,

a second spreader spaced above the plurality of ports and having an opening for allowing passage of the low rate flame,

means disposed within the opening for dispersing the low rate flame to enhance the burning of the gas in the low rate flame.

4. A burner apparatus for operating at both low and high rates comprising a burner member having an inlet for receiving gas and a port for projecting gas in a first direction such that during a high rate of operating a high rate flame extending for at least a predetermined distance along the first direction is produced and during a low rate of operation a low rate flame deviating from the first direction in less than said predetermined distance to a second direction transverse to the first direction is produced,

a first spreader spaced in the first direction from the burner member in the path of the high rate flame for enhancing the burning of the gas in the high rate flame,

a second spreader spaced in the second direction from the port and having an opening for allowing passage of the low rate flame,

means disposed within the opening for dispersing the low rate flame to enhance the burning of the gas in the low rate flame,

said second spreader including a horizontal plate-like portion, and

said dispersing means including a tab projecting from the plate-like portion into the opening.

5. A burner apparatus as claimed in claim 4 wherein the tab has an enlarged head portion within the opening. 6. A burner apparatus for operating at both high and low rates comprising a hollow annular member disposed about a vertical axis and having a plurality of spaced outward facing burner ports such that during a high rate of operation outward extending flames are produced' a second spreader annularly'disposed about the annular member above the burner ports and having a plurality of openings adjacent the annular member for allowing passage of the upward extending flames, and

means disposed in each of the openings for dispersing the upward extending flames to promote the buming of the upward extending flames.

7. A burner apparatus as claimed in claim 6 which includes a flame sensing element,

means for mounting the flame sensing element along the vertical axis above the hollow annular member,

means for directing the upward extending flame toward the flame sensing element after passing through the openings, and

an inward facing port in the hollow annular member for directing a flame against the flame sensing element during operation at the high rate.

8. A burner apparatus for operating at both high and low rates comprising a hollow annular member disposed about a vertical axis having an inlet for receiving gas and a plurality of spaced outward facing burner ports such that high rate streams of burning gas are projected radially outward from the annular member and low rate streams of burning gas are projected upward along the outer surface of the annular member and convergent toward the axis over the top of the annular member, a

a first spreader having an upward flaring frusto-cone portion disposed about the annular member in the outward paths of the-high rate streams and leg portions mounting the second spreading member on the annular member below the outward facing burner ports,

said first spreader having an opening between the frusto-cone portion and the annular member,

a second spreader mounted on the annular member and having a plate-like portion spaced above the outward facing burner ports,

said plate-like portion having a plurality of openings adjacent the annular member for passing the low rate streams of burning gas,

a flame sensing element,

means for mounting the flame sensing element on the vertical axis above the annular member in the path of the convergent low rate streams,

said annular member having an inward facing burner port for projecting a stream of burning gas against the flame sensing element during operation at the high rate, and

a plurality of projections each having an enlarged head portion extending into each of the openings in the plate-like portion for dispersing the low rate streams to enhance the burning of the low rate streams.

' a at

Claims

1. A burner apparatus for operating at both low and high rates comprising a burner member having an inlet for receiving gaseous fuel and a port for projecting non-aerated gaseous fuel in a first direction such that during a high rate of operation a high rate flame extending for at least a predetermined distance along the first direction is produced and during a low rate of operation a low rate flame deviating from the first direction in less than said predetermined distance to a second direction transverse to the first direction is produced, a first spreader spaced in the first direCtion from the burner member in the path of the high rate flame for enhancing the burning of the gaseous fuel in the high rate flame, a second spreader spaced in the second direction from the port and having an opening for allowing passage of the low rate flame, and means disposed within the opening for dispersing the low rate flame to enhance the burning of the gaseous fuel in the low rate flame.

2. A burner apparatus for operating at both low and high rates comprising a burner member having an inlet for receiving gas and a port for projecting gas in a first direction such that during a high rate of operation a high rate flame extending for at least a predetermined distance along the first direction is produced and during a low rate of operation a low rate flame deviating from the first direction in less than said predetermined distance to a second direction transverse to the first direction is produced, a first spreader spaced in the first direction from the burner member in the path of the high rate flame for enhancing the burning of the gas in the high rate flame, a second spreader spaced in the second direction from the port and having an opening for allowing passage of the low rate flame, means disposed within the opening for dispersing the low rate flame to enhance the burning of the gas in the low rate flame, a flame sensing element spaced from the port beyond the dispersing means in the path of the low rate flame, and said burner member having a second port for projecting gas against the flame sensing element when the burner is operating at the high rate.

3. A burner apparatus for operating at both low and high rates comprising a burner member having an inlet for receiving gas and a plurality of spaced ports for projecting gas in a substantially horizontal direction such that during a high rate of operation a high rate flame extending for at least a predetermined distance along the horizontal direction is produced and during a low rate of operation an upward extending flame deviating from the horizontal direction in less than said predetermined distance is produced, a first spreader spaced in the horizontal direction from the burner member in the path of the high rate flame for enhancing the burning of the gas in the high rate flame, a second spreader spaced above the plurality of ports and having an opening for allowing passage of the low rate flame, means disposed within the opening for dispersing the low rate flame to enhance the burning of the gas in the low rate flame.

4. A burner apparatus for operating at both low and high rates comprising a burner member having an inlet for receiving gas and a port for projecting gas in a first direction such that during a high rate of operating a high rate flame extending for at least a predetermined distance along the first direction is produced and during a low rate of operation a low rate flame deviating from the first direction in less than said predetermined distance to a second direction transverse to the first direction is produced, a first spreader spaced in the first direction from the burner member in the path of the high rate flame for enhancing the burning of the gas in the high rate flame, a second spreader spaced in the second direction from the port and having an opening for allowing passage of the low rate flame, means disposed within the opening for dispersing the low rate flame to enhance the burning of the gas in the low rate flame, said second spreader including a horizontal plate-like portion, and said dispersing means including a tab projecting from the plate-like portion into the opening.

5. A burner apparatus as claimed in claim 4 wherein the tab has an enlarged head portion within the opening.

6. A burner apparatus for operating at both high and low rates comprising a hollow annular member disposed about a vertical axis and having a plurality of spaced outward facing burner ports such that during a high rate of operation outward extending flames are produced and during a low rate of operation upward extending flames are produced, a first spreader annularly disposed about the annular member in the paths of the outward extending flames for promoting the burning of the outward extending flames, a second spreader annularly disposed about the annular member above the burner ports and having a plurality of openings adjacent the annular member for allowing passage of the upward extending flames, and means disposed in each of the openings for dispersing the upward extending flames to promote the burning of the upward extending flames.

7. A burner apparatus as claimed in claim 6 which includes a flame sensing element, means for mounting the flame sensing element along the vertical axis above the hollow annular member, means for directing the upward extending flame toward the flame sensing element after passing through the openings, and an inward facing port in the hollow annular member for directing a flame against the flame sensing element during operation at the high rate.

8. A burner apparatus for operating at both high and low rates comprising a hollow annular member disposed about a vertical axis having an inlet for receiving gas and a plurality of spaced outward facing burner ports such that high rate streams of burning gas are projected radially outward from the annular member and low rate streams of burning gas are projected upward along the outer surface of the annular member and convergent toward the axis over the top of the annular member, a first spreader having an upward flaring frusto-cone portion disposed about the annular member in the outward paths of the high rate streams and leg portions mounting the second spreading member on the annular member below the outward facing burner ports, said first spreader having an opening between the frusto-cone portion and the annular member, a second spreader mounted on the annular member and having a plate-like portion spaced above the outward facing burner ports, said plate-like portion having a plurality of openings adjacent the annular member for passing the low rate streams of burning gas, a flame sensing element, means for mounting the flame sensing element on the vertical axis above the annular member in the path of the convergent low rate streams, said annular member having an inward facing burner port for projecting a stream of burning gas against the flame sensing element during operation at the high rate, and a plurality of projections each having an enlarged head portion extending into each of the openings in the plate-like portion for dispersing the low rate streams to enhance the burning of the low rate streams.