US3037553A - Gas burner - Google Patents

Description

June 5, 1962 G. w. JACKSON 3,037,553

GAS BURNER Filed Oct. 29, 1957 2 Sheets-Sheet 1 F/G. F/G. 2.

INVENTOR. GEORGE W. JACKSON ATTORNEYS June 5., 1962 G. w. JACKSON GAS BURNER 2 Sheets-Sheet 2 Filed Oct. 29, 1957 INVEN TOR. GEORGE W. JACKSON 3 Y E N R O W A United States Patent 3,037,553 GAS BURNER George W. Jackson, alt Lake City, Utah, assignor to Utah Hydro Corporation, Salt Lake City, Utah, a corporation of Utah Filed on. 29, 1e57, Ser. No. 693,188 11 Claims. (Cl. 15899) This invention relates to gas burners for firing industrial and domestic heating equipment, and is concerned with providing such a burner having important structural and functional advantages over those presently known.

Conventional gas burners are wasteful of heat, because of the great excess of air required to maintain proper combustion and flame stability.

An object of the invention is to provide a gas burner that will operate at top efficiency, without excessive flow of air through the heating equipment. This does away with the usual undesirable cooling effect attributable to such air, and results in a considerable saving in fuel. Thus, the invention provides for very close proportioning of the air-gas mixture for high combustion efficiency.

Conventional gase burners must be equipped with pressure regulators in areas Where there are likely to be significant changes in pressure in the gas supply from time to time. This is a safety measure, in view of the inability of conventional burners to sustain a flame under conditions of wide divergencies from a given supply pressure of the gas being burned.

An object of this invention is to provide a gas burner that will sustain burner flames and maintain efilcient fuel combustion over a range of pressures from extremely low to extremely high, thereby avoiding the usual gas pressure regulator at the burner. An important advantage derived from this unique operating feature is the opportunity afforded for using LP gas as a standby fuel, without alteration of the burner and by merely opening a valve.

In addition to the above, important objects of the invention are to provide an exceptionally simple burner construction which eliminates the corrosion and deterioration normally occurring in conventional burners due largely to excessive heating of component parts wd to deposition of carbon; to provide a burner capable of installation in the fire door of most types of boilers and furnaces, so as to enable effective conversion of existing heating equipment to gas operation without interference with the firing apparatus or fuel supply previously used; to provide a burner having the above advantages, but still susceptible of fully automatic control in largely conventional fashion; and to provide a burner that will suc cessfully and safely burn pure hydrogen gas, as customarily available at oil refineries.

An outstanding feature in the accomplishment of the foregoing objects is the mixing of the gas With air following (rather than before) its discharge at the burner as a multiplicity of gas jets. By so doing, flame retention is assured over a wide range of gas pressure variation when the burner is constructed as here claimed.

In accordance with the invention, a number of gas jet nozzles are provided in mutually spaced relationship along a burner pipe supplying the gas, so as to produce unaerated gas jet streams of high velocity as compared to the gas supply itself. In combination therewith is provided an air injection duct, comprehending but spaced apart from the several gas jet nozzles, and disposed within the path of the gas jet streams therefrom, together with gas-impingement structure strategically disposed within the air injection duct for breaking up the gas jet streams in the presence of combustion air. The airinjection duct is formed to provide a relatively low velocity zone for gas ignition and flame propagation.

3,037,553 Patented June 5, 1962 structure is preferably mounted within a door-equipped frame adapted for attachment to a furnace or broiler over 1 the usual fire door opening in place of the customary fire door. Means are provided for automatically opening and closing the door of such frame with the opening and closing of the valve that controls the supply of gas to the burner. All other openings for the inflow of air to the furnace or boiler are sealed off, so that such door provides the sole air supply for the burner.

It is a feature of the invention that the automatic controlsand the mechanism actuated thereby for opening and closing the door-may be largely of conventional type obtainable on the open market. However, a unique aspect is the provision of a lost motion connection between the door and the actuating mechanism therefor, whereby the gas control valve can close, even though the door may he accidentally jammed open.

Further objects and features of the invention will become apparent from the following detailed description of the presently preferred embodiments thereof illustrated in the accompanying drawings.

In the drawings:

FIG. 1 represents a front elevation of one successful embodiment of the invention as constructed for installation in place of the customary fire door of a furnace or boiler, the air-access door being shown in the closed position as it is when the gas control valve is closed and the burner is not operating;

FIG. 2, a rear elevation of the embodiment of FIG. 1;

FIG. 3, a side elevation looking from the right in FIG. 1, the door-actuating connection being shown in vertical section;

FIG. 4, a view corresponding to that of FIG. 3, but illustrating the air-access door in its open position as it is when the burner is operating;

FIG. 5, a view corresponding to that of FIG. 4, but

illustrating how the gas control valve is free to close even FIG. 8, a full face view of a somewhat different embodiment of burner structure, shown apart from association with a furnace or boiler;

FIG. 9, a vertical section taken on the line 99 of FIG. 8; and

FIG. 10, a detail transverse section taken through a single burner pipe assemblage similar to those of FIGS. 1-7, but differing in certain respects which are presently preferred, the view corresponding to a portion of FIG. 6 but being drawn to an enlarged scale.

Referring to the drawings:

The gas burner and installation thereof illustrated in FIGS. l-7 is typical of the application of the invention to an industrial or domestic boiler or furnace. The burner assembly, made up in the present instance of several individual burner pipes 10 and of therewith associated airinjection ducts 11, is mounted within a door frame 12 adapted for attachment to a boiler or furnace 13, FIG. 7,

over the usual fire door opening 13a thereof in place of 3 main through a conventional control valve 16 having a supply line (not shown) connected at 16a. Valve 16 is equipped with a standard type of thermostat-controlled actuating mechanism 17 adapted to also simultaneously control draft by means of a lever 17a.

Each of the burner pipes 11! is rectilinearly elongate in this instance, and is provided with a plurality of gas jet nozzles at intervals along its length. In the form illustrated, the jet nozzles 20 are respective holes drilled through the wall of the burner pipe in series alignment along the length of such pipe. The number of burner pipes and the number of gas jet nozzles 24) in each pipe will depend upon the size and capacity of any given installation.

Each of the air injection ducts 11 is short relative to its burner pipe 10, but is elongate in cross-section to provide an elongate inflow opening 21 and an elongate outflow opening 22 at its opposite ends. Between such openings is a throat 23 leading from inflow opening 21 to an ignition chamber 24 of enlarged cross-section immediately in advance of outflow opening 22. In this instance, the throat 23 converges from inlet opening 21 to a constricted discharge 25 opening into ignition chamber 24.

As is clear from the drawing, throat opening 25 is less in area than outflow opening 22 so that ignition chamber 24 will provide a zone of relatively low pressure. Also, to enhance the low pressure effect on the high velocity stream issuing from throat opening 25, there is an abrupt increase in cross-sectional area between throat and ignition chamber substantially at the throat opening 25. It will be recognized, of course, that the air-inflow opening 21 is sufficiently large in relation to the gas discharge capacity of the jet nozzles to provide at least enough primary air to permit ignition and support combustion of the gas within low pressure chamber 24.

It will also be noted from the drawing that throat 23 has approximately the same depth as ignition chamber 24. This is for the purpose of preventing flashback and combustion within the throat when burning highly volatile gases, such as pure hydrogen and most natural gases.

The ducts 11 are positioned in spaced relation to their respective burner pipes 10, having their inflow openings 21 facing the gas jet nozzles 20 of the burner pipes and having both such inflow openings and the outflow openings 22 extending along the lengths of the respective burner pipes within the line of flow of gas streams 26, FIG. 7, issuing from the respective nozzles 20, so that such gas streams from each burner pipe pass into and tlrough the corresponding duct in side-by-side relations 1p.

For securing the ducts in their specified spaced relationship With the respective burner pipes, each pipe and duct assembly has end plates 27 secured, as by welding, to both burner pipe and duct.

It is a feature of the invention that the gas supplied to the burner pipes 10 and the gas issuing from the jet nozzles 20 as jet streams 26 is unaerated; further, that the velocity of such gas jet streams 26 tends to induce a greater flow of air through duct 11 than would be true by draft alone.

Aeration of the gas is accomplished with great efficiency by positioning gas-impingement structure within each duct 11 adjacent the discharge end of the throat 23. The gas streams 26 strike such impingement structure, and are broken up and diffused in the presence of the surrounding air flow, whereby aeration is achieved in a peculiarly effective manner.

In this instance, the gas impingement structure comprises a series of short bars 28 extending transversely of duct inlet and outlet openings 21 and 22, respectively, at the bottom of ignition chamber 24 at and across the discharge opening 25 of throat 23, and an elongate bar 29 resting upon and bridging the transverse bars 28 and extending longitudinally of throat 23 and centrally of its discharge opening 25. Both the transverse bars 28 and the longitudinal bars 29 register with gas jet nozzles 20, although, as indicated, there need not be a transverse bar for each of the nozzles.

Ignition of the gas issuing from throat 23 and aerated as described takes place in the comparatively low pressure protected area provided by ignition chamber 24. The resulting flames sweep out from the burner into the combustion zone 13b of the boiler or furnace 13 somewhat as indicated at 30, FIG. 7.

The bars 23 and 29 are preferably stainless steel, in order to withstand the combustion temperatures prevailing thereat.

As can be seen from the orientation of the several burner pipe and duct assemblies in the particular burner illustrated, placement and direction thereof Within the confines of frame 12 may be as found most advantageous for flame distribution in any given installation.

A conventional pilot light having flame rod 35a for flame rectification and ignition electrode (not shown) is provided at any appropriate location, for example that shown, gas being supplied thereto through pipe 36 under control of a manually operated valve 37 with which an auxiliary gas supply line (not shown) connects.

It is a feature of the invention that all air entering the boiler or furnace in which the burner is installed passes through the burner under strict control of the gassupply valve assembly. To this end, all auxiliary air openings leading into the boiler or furnace 13 are tightly sealed, and a tightly-closing door 40, hinged at 41, is provided across much of the front of the frame 12. The remainder of the front of frame 12 is permanently closed, as by means of a plate 12b.

A handle is provided for the door 40 in the form of a lever arm 42, which is connected by an angular tube extension 43 to damper-actuating arm 17a of the thermostatically controlled actuating mechanism 17 for gas supply valve 16.

The actual connection between tubular handle extension 43 and arm 17a is made by a rod 44 telescoped within such tube extension 43, FIG. 5, and pivotally connected at 45 with actuating arm 17a, so that if, for any reason, door 40 is jammed open, the actuating mechanism 17 is not prevented from cutting off the gas in response to thermostatic control.

Closing of door 40 is effected by a spring 45, and opening thereof by lever 17:: and rod 44.

The burner of the invention may take various forms, for example it may be circular as shown in FIGS. 8 and 9.

In this embodiment, a single elongate burner pipe of annular formation is supplied with gas under pressure from supply line 51. A series of gas jet nozzles 52 are provided at intervals along the circular length of such burner pipe 52.

A single duct 53, having circularly elongate inlet open ing 54 and outlet opening 55 is secured in spaced relationship with burner pipe 50 by a leg extension 53a of the duct itself and by a series of rods 56 provided at intervals about the outer periphery of the burner pipe and duct.

In this instance, the gas impingement structure is provided by a series of transverse bars 57 disposed radially of the axis of the burner.

Where no longitudinal bar is provided, as in this embodiment, a transverse bar is positioned over each gas jet nozzle.

The positioning of the gas impingement structure of FIGS. 1-7 has given quite satisfactory results in practice. However, we have found more recently that, in many instances, it is preferable to position the longitudinal bar within the throat, as indicated in FIG. 10.

In the embodiment of FIG. 10, which is similar to that of FIGS. 1-7 in most particulars, the longitudinal bar 60 is within the throat 61 adjacent the constricted dis charge opening 62 thereof and below the transverse bars 63. Also, the outer end of the duct bordering the longitudinal dimension of outflow opening 64 thereof is bent inwardly to provide protective strips 65 along such outflow opening. However, as shown by the drawing, the opening 62 is still considerably less in area than is the outflow opening 64.

Whereas this invention is here illustrated and described with respect to certain presently preferred embodiments thereof, it should be understood that various changes may be made therein without departing from the scope of the claims which here follow.

I claim:

1. A gas burner for industrial and domestic heating equipment, comprising an elongate burner pipe having a plurality of gas jet nozzles formed at intervals along its length; an air-injection duct having aligned inflow and outflow openings at its opposite ends; means positioning said duct in spaced relationship with said burner pipe with its inflow opening facing said nozzles and with both its inflow and outflow openings extending along the burner pipe, so that the gas streams issuing from said nozzles will pass directly into and through said duct in side by side relationship, said duct being considerably shorter between its inflow and outflow openings than it is long and being formed with a throat leading from said inflow opening to an enlarged ignition chamber at said outflow opening, both throat and ignition chamber likewise extending along the burner pipe with the opening between said throat and chamber being less in area than said outflow opening and the depth of the throat being approximately the same as the depth of the ignition chamber; and a series of bars extending transversely of the throat of the duct adjacent the discharge opening of said throat and within the confines of the ignition chamber directly above respective gas jet nozzles.

2. The gas burner of claim 1, wherein both the burner pipe and the duct are of endless configuration.

3. The gas burner of claim 2, where the endless configuration is circular.

4. The gas burner of claim 1, wherein the bars are disposed right at the discharge opening of the throat.

5. The gas burner of claim 4, wherein the gas impingement structure also comprises an elongate bar extending longitudinally of the discharge opening of the throat and directly above the gas jet nozzles.

6. The gas burner of claim 5, wherein the elongate bar is disposed within the throat.

7. The gas burner of claim 1, wherein the throat of the duct is constricted at its discharge opening.

8. A gas burner for industrial and domestic heating equipment, comprising an elongate burner pipe having a plurality of gas jet nozzles formed at intervals along its length; an air-injection duct having aligned inflow and outflow openings at its opposite ends; means positioning said duct in spaced relationship with said burner pipe with its inflow opening facing said nozzles and with both its inflow and outflow openings extending along the burner pipe, so that the gas streams issuing from said nozzles will pass directly into and through said duct in side by side relationship, said duct being formed with a thuoat leading from said inflow opening to an elarged ignition chamber at said outflow opening, both throat and ignition chamber likewise extending along the burner pipe with the opening between said throat and chamber being less in area than said outflow opening and the depth of the throat being approximately the same as the depth of the ignition chamber; and a series of bars extending transversely of the throat of the duct adjacent the discharge opening of said throat and within the confines of the ignition chamber directly above respective gas jet nozzles.

9. The gas burner of claim 8, wherein the bars are disposed right at the discharge opening of the throat.

10. The gas burner of claim 9, wherein the gas impingement structure also comprises an elongate bar extending longitudinally of the discharge opening of the throat and directly above the gas jet nozzles.

11. The gas burner of claim 10, wherein the elongate bar is disposed within the throat.

References Cited in the file of this patent UNITED STATES PATENTS 1,810,373 Roberts June 16, 1931 1,844,187 Smith Feb. 9, 1932 1,852,443 Anderson Apr. 5, 1932 1,903,903 McLavy et al Apr. 18, 1933 1,962,113 Elmore June 12, 1934 1,963,009 Wunsch June 12, 1934 2,661,056 Kuehne Dec. 1, 1953 FOREIGN PATENTS 547,132 Great Britain Aug. 14, 1942 464,438 Italy July 2, 1951

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