Plural rate burner with deflection of high rate flame against flame sensing element

Abstract

A plural rate burner apparatus has a plurality of outward directed ports in a burner member from which burning gas at a low rate of operation impinges upon a flame sensing element above the burner. At a high rate of operation a portion of the flame from the plurality of ports is deflected against the flame sensing element.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to burners for gaseous fuel, and in particular, to burners for operating at more than one rate.

2. Description of the Prior Art

Prior art burners for operating at high and low rates utilized a hollow annular burner member disposed around a vertically extending flame sensing element with circumferially spaced and outwardly directed burner ports in the outer periphery of the burner member which at a low rate produced a flame converging upward and inward against the flame sensing element; at the high rate, a burner port provided in the inner wall of the annular burner member sustains a flame directed inward against the flame sensing element. Such burners require machining of the inner portion of the burner member to form the inward facing burner port; the inner port must be sufficiently small to provide for heating of the flame sensing element without extending greatly beyond the flame sensing element; and the inner portion of the burner member must be made of materials which do not promote carbonaceous deposits.

SUMMARY OF THE INVENTION

The invention is summarized in that a burner apparatus for operating at both low and high rates includes a burner member having an inlet for receiving gas, a first port for projecting burning gas in a first direction at the high rate of operation such that burning gas from the first port at the low rate of operation deviates from the first direction to a second direction; a flame sensing element spaced from the first port in the path of burning gas deviated to the second direction; said burner member having a second port for projecting burning gas in a third direction at the high rate of operation; and means spaced from the second port in the third direction for deflecting burning gas projected by the second port from the third direction to a direction impinging upon the flame sensing element.

An object of the invention is to provide a burner apparatus operable at both low and high rates with improved heating of a flame sensing element at the high rate of operation.

Another object is to eliminate machining operations in the manufacture of a substantial portion of a burner.

It is also an object of the invention to reduce the amount of the burner which is exposed to burning fuels so that more non-exposed portions can be made from easier forming and less expensive materials.

A further object of the invention is to allow for the provision of a larger port size for generating a flame to heat a flame sensing element at the high rate of operation.

It is still a further object of the invention to provide a burner apparatus operable at both high and low rate wherein all of the ports are accessible for easier cleaning.

One advantage of the invention is that a larger port for generating a flame impinging upon a flame sensing element does not clog as readily as smaller ports.

A feature of the invention is a provision of a pilot target in the path of a portion of a burning gas pattern projected from outwardly directed ports during a high rate of operation to deflect the flame portion against a flame sensing element.

Other objects, advantages and features of the invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a burner system with a burner apparatus shown in cross section operating at a high rate in accordance with the invention.

FIG. 2 is a top view of a portion of the burner apparatus taken along line 2--2 of FIG. 1.

FIG. 3 is a cross section view of a broken away portion of the burner apparatus shown in FIG. 1 illustrating a low rate of operation of the burner apparatus.

FIG. 4 is a cross section view of a broken away portion of a modified apparatus in accordance with the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As illustrated in FIG. 1, the present invention is embodied in a burner system which includes a plural rate control device indicated generally at 10 connected to a gaseous fuel source (not shown) and a conduit 12 which communicates to a burner fitting or inlet 14 of a burner member indicated generally at 16 in a burner apparatus indicated generally at 17. Also the control device 10 is connected by a line 18 to a flame sensing element 20 in the burner apparatus 17. The control device 10 is any suitable control device capable of selectively supplying a high pressure gas to the conduit 12 for high rate operation of the burner apparatus 17 and supplying a low pressure gas to the conduit 12 for standby or low rate operation of the burner apparatus 17. In addition, the control device 10 includes thermostat facilities for controlling the low and high rate operation, and safety valve facilities controlled by conditions in line 18 to interrupt the flow of gas in conduit 12 in the absence of the sensing of a flame by the sensing element 20. A suitable control device is described in U.S. Patent Application Ser. No. 98,246 by Jay R. Katchka and Henry C. Braucksiek filed on Dec. 15, 1970 now U.S. Pat. No. 3,762,639.

The annular burner member 16 has an outer peripheral tubular section 24 and inner tubular section 26 coaxially disposed about a vertical axis and suitably joined, for example by welded beads, at upper and lower ends to form an annular chamber 28 into which the inlet 14 communicates. As shown in FIG. 2, a plurality of circumferially spaced and radially outward facing burner ports 32 are formed in an arcuate portion of the tubular section 24 opposite to the inlet 14. For example, the arcuate portion with the ports 32 is shown extending for approximately 285.degree. of the circumference of the burner member 16. The ports 32 have a size selected to sustain a generally radially outward extending flame when the control device 10 applies a high pressure gas to the chamber 28, and to sustain a flame extending generally upward from the ports 32 along the upper outer wall of the burner member 16 when the control device 10 applies a low pressure gas to the chamber 28.

A frusto-conical flame target 34, shown in FIG. 1, has legs 36 secured to the outer tubular section 24 to support the target 34 in the path of the outwardly directed flames from the burner ports 32 at the high rate of operation. The conical target 34 is sufficiently spaced from the burner member 16 to leave an opening 38 between the target and the burner member 16 to allow for passage of air to be entrained in the gas emitted from burner ports 32.

The flame sensing element 20 is secured within a tubular spring clip member 40 which is mounted on a bottom support 42 secured to the bottom of the burner member 16. The support 42 has air passage openings 43. The flame sensing element 20 extends along the vertical axis of the annular burner member 16 to a position above the burner member 16 into the path of converging flames from the burner ports 32 at the low rate of operation. The flame sensing element is any suitable temperature responsive device, such as a thermo-couple, for generating conditions in line 18, such as electrical currents, to operate the safety valve facilities of the control device 10.

A frusto-conical flame shield 44 has a spaced top 46 supported by legs 48 and is mounted by tabs 50 to a annular shield support member 52 which has spokes 54 secured to a collar 56 mounted on the upper end of the burner member 16. Openings 58 between the spokes 54 allow for passage of upwardly extending flames from the burners ports 32.

A burner port 60 is formed in the outer tubular section 24 above the inlet 14 and extends upward and radially outward, for example at a 45.degree. angle to the horizontal. A pilot type target portion 62 is formed in the shield 44 in the path of burning fuel projected from the burner port 60 when the control device 10 applies high pressure gas to the chamber 28. The target 62 has a curved portion 64 which terminates in a relatively sharp edge 66 directed toward the flame sensing element 20. The target 62 is formed with a concave curvature, that is a curvature in a horizontal cross section which has substantially less radius than the curvature of the shield 44, to form a channel 68 for receiving and preventing substantial diffusion of a projected flame from the port 60. The target 62 is positioned to form an angle of incidence with projected gas from the port 60 selected to direct a substantial portion of the burning gas upward in the channel 68.

In operation of the burner system illustrated in FIGS. 1, 2 and 3, gaseous fuel is supplied from the source by the control device 10 through conduit 18 to inlet 14 and chamber 28 of the burner member 16. When the thermostat facilities of the control device 10 operate to command the generation of heat, the gas pressure supplied to chamber 28 is relatively high to cause high rate operation of the burner apparatus 17. When the thermostat facilities of the control device call for the absence of heat generation, the gas pressure supplied to chamber 28 is relatively low to cause standby or low rate operation of the burner apparatus 17.

At the low rate of operation shown in FIG. 3, gas from the burner ports 32 produces a generally upward extending flame which follows the outer wall of the burner member 16 upwardly and converges over the top of the burner member 16 to impinge upon the flame sensing element 20. The impingement of the converging flame from ports 32 operates the flame sensing element which maintains the safety valve facilities in the fuel control 10 in an open state.

At the high rate of operation illustrated in FIG. 1, gas from the ports 32, projects radially outward from the burner member 16 impinging upon the target 34 to cause entrainment of air passing through the opening 38 in the radially projecting fuel to form a generally outward and upward extending flame from the burner apparatus which is suitable for heating an appliance. Gas projected from the burner port 60 radially outward and upward from the burner member 16 impinges upon the target 62 and is deflected upward in the channel 68 which tends to prevent substantial spreading and diffusion of the deflected flame. The flame follows the curved portion 64 off the edge 66 impinging upon the flame sensing element 20 to maintain the flame sensing element 20 operated. The relatively sharp edge 66 at the termination of curved portion 64 prevents the deflected flame emitted from the burner port 60 from following the shield 44.

The utilization of a pilot target for deflecting a portion of the outwardly projected flame from the burner member 16 against the flame sensing element 20 at a high rate of operation eliminates the necessity of forming a burner port in the inner tubular section 26; thus eliminating the necessity of non-nickel containing chromium-steel alloys for the inner tubular section 26. The inner tubular section 26 may be made from a material such as a nickel stainless steel alloy which is easier to form and less expensive in manufacture. Additionally the flame from the burner port 60 at the high rate of operation travels a substantially greater distance from the burner port 60 to the target 62 and back to the flame sensing element 20 thus allowing the burner port 60 to have a larger size than burner ports formed in the inner tubular section 26. The larger port is less likely to clog. Also, the location of the burner port 60 on the outer tubular section 24 makes the burner port 60 more readily accessible for cleaning than burner ports which are formed in the inner tubular section 26.

A modification of the burner apparatus is illustrated in FIG. 4 wherein some parts are identified with the same numerals used in FIGS. 1-3 to indicate such parts have similar structure and/or function. The shield 44 has an extension 162 which is reverse bent to extent upwardly into the shield 44 to form a pilot target for the flame from the burner port 60. The extension 162 is formed concave to form a channel 168 and a curved portion 164 terminating in a edge 166 for directing the burning fuel from the burner port 60 toward the flame sensing element 20 in a manner similar to the channel 68, curved portion 64 and edge 66 of the burner apparatus shown in FIG. 1.

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

Claims

What is claimed is:

1. A burner apparatus for operating at both high and low rates comprising

a burner member having a chamber, an inlet communicating with the chamber, and an outer peripheral section with a plurality of first ports for projecting burning gas outward from the burner member at the high rate of operation and upward from the burner member at the low rate of operation;

a flame sensing element above the burner member in the path of upward burning gas at the low rate of operation;

said outer peripheral section of the burner member having a second port for projecting burning gas outward at the high rate of operation; and

means spaced outwardly from the outer peripheral section of the burner member in the path of outward-projected burning gas from the second port for deflecting outward projected burning gas from the second port upward to a direction impinging upon the flame sensing element.

2. A burner apparatus as claimed in claim 1 wherein the second port is directed upwardly and outwardly from the burner member.

3. A burner apparatus as claimed in claim 1 wherein

the burner member is a hollow annular burner member disposed about a vertical axis and the plurality of first ports are directed substantially outward,

the flame sensing element is mounted along the vertical axis, and

the second port of the burner member is projected upwardly and outwardly from the annular burner member.

4. A burner apparatus for operating at both high and low rates comprising

a burner member having an inlet for receiving gas, a first port for projecting burning gas in a first direction at the high rate of operation such that burning gas from the first port at the low rate of operation deviates from the first direction to a second direction;

a flame sensing element spaced from the first port in the path of burning gas deviated to the second direction;

said burner member having a second port for projecting burning gas in a third direction at the high rate of operation; and

means including a curved portion terminating in an edge and spaced from the second port in the third direction for deflecting burning gas projected by the second port from the third direction to a direction impinging upon the flame sensing element.

5. A burner apparatus for operating at both high and low rates comprising

a hollow annular burner member disposed about a vertical axis and having an inlet for receiving gas and having a plurality of first ports directed substantially outward for projecting burning gas outward at the high rate of operation such that burning gas from the plurality of first ports at the low rate of operation deviates upward;

a flame sensing element at least partially mounted above the burner member in the path of upward burning gas from the first burner ports,

a second port of the burner member directed upwardly and outwardly in a third direction from the annular burner member for projecting burning gas upwardly and outwardly at the high rate of operation; and

means including a curved portion terminating in an edge and spaced from the second port in the third direction for deflecting burning gas from the second port toward the flame sensing element.

6. A burner apparatus for operating at both low and high rates comprising

a burner member disposed about a vertical axis and having an inlet and an outer peripheral section with a plurality of outward directed ports circumferentially spaced in the outer peripheral section;

means for controlling a supply of gas connected to the inlet of the burner member to produce an outward flaring flame pattern from the burner member at the high rate of operation and to produce an upward flame pattern at the low rate of operation;

a flame sensing element disposed above the burner member in the path of the upward flame pattern;

said controlling means including safety valve means responsive to the flame sensing element for terminating gas flow in the absence of flame; and

means spaced outwardly from the outer peripheral section of the burner member in the path of outward-flaring flame for deflecting a portion of the outward flaring flame pattern upward toward the flame sensing element.

7. A burner apparatus comprising

means for controlling a supply of gas to produce a high gas pressure at a high rate of operation and to produce a low gas pressure at a low rate of operation;

said controlling means including thermostat means for selectively producing the high and low rates of operation of the controlling means, and safety valve means for preventing gas flow;

a hollow annular burner member disposed about a vertical axis and having an inlet connected to the controlling means;

said burner member having a plurality of outwardly directed ports for projecting burning gas substantially outward at the high gas pressure and for producing a vertically extending flame at the low gas pressure converging inward above the burner member toward the vertical axis;

said burner member having an outwardly and upwardly directed port for projecting burning gas outwardly and upwardly from the burner member at the high gas pressure;

a flame sensing element along the vertical axis and above the burner member in the path of the convergent flame for operating the safety valve means;

a shield disposed about the upper portion of the annular burner member and the flame sensing element; and

a pilot target in the path of burning gas projected from the outwardly and upwardly directed port for deflecting burning gas toward the flame sensing element.

8. A burner apparatus as claimed in claim 7 wherein the pilot target is a curved portion of the shield terminating in an edge.

9. A burner apparatus as claimed in claim 7 wherein

the burner member includes an inner tubular section and an outer tubular section joined at their upper and lower ends, and

the inlet, the plurality of outwardly directed ports and the outwardly and upwardly directed port are formed in the outer tubular section.