US3144076A - Flame retaining gas burner - Google Patents

Description

Aug. 11, 1964 R. w. IMARS ETAL FLAME RETAINING GAS BURNER 2 Sheets-Sheet 1 Filed Oct. 21. 1957 INVENTORS ROBERT w. IMARS BY WILL/AM L.R1EHL 6 HTTORNEY Au 11, 1964 R.W. [MARS ETAL 3,144,076

FLAME RETAINING GAS BURNER Filed Oct. 21, 1957 2 Sheets-Sheet 2 INVENTORS ROBERT M MARS BY WILL/AM L. RIEHL ATTOR E V United States Patent 3,144,076 FLAME RETAINING GAS BURNER Robert W. Imars, New Hartford, and William L. Riehl,

Utica, N.Y., assignors to International Heater Company, Utica, N.Y., a corporation of New York Filed Oct. 21, 1957, Ser. No. 691,393 4 Claims. (Cl. 158-413) This invention relates to burners, and more particularly to gas burners of the type normally employed in heating furnaces for buildings. The invention also relates to an improved method of retention of the flame at the burner head or tip.

Atmospheric burners previously presented have produced a flame which was not well adapted to be controlled as to size and shape. Such burners were therefore not Well suited to be used as conversion burners in a furnace designed for the forced draft or power type oil burners. Combustion zones for the oil burner are usually compact. Accordingly, a compact, controlled flame is desirable in order to achieve maximum heating and flame efficiency therefrom.

Atmospheric burners heretofore presented have had another undesirable condition in that static pressures building up within the burner tube cause a noisy concussion or flash-back during extinguishment of the flame.

Furthermore, due to the velocity of the fuel-air mixture issuing from the burner head, the velocity of flame propagation is likely to be exceeded by this mixture velocity, thus causing blow-off of the flame, and subsequent extinguishment thereof. This causes a dangerous condition in that the air around the furnace can become both poisonous and highly explosive. Attempts have been made to correct this condition by the provision of two velocities at the burner head, thus to provide a mixture of fuel-air issuing from the head and surrounding the main stream at a reduced velocity. However, the size and shape of the flame could not be controlled to any great extent with this method.

It is therefore a primary object of this invention to provide a burner which accomplishes combustion of gas within a more limited cubic zone than was heretofore possible with an atmospheric burner.

It is a further object of this invention to force fuel and combustion air into close association in the combustion zone using atmospheric combustion and without employing power means of any kind to this end.

Another important object of this invention is to provide a method of retention of the flame at the burner head by providing a plurality of velocities of fuel-air mixture at the burner head and controlling the secondary air as it enters the combustion zone.

A further object is the provision of means for achieving maximum turbulence of the flame and rapid completion of combustion in order to achieve maximum efliciency of the burner.

In accordance with the present invention, a burner for gaseous fuel is provided utilizing atmospheric combustion and not aided in any manner by mechanical or electrical or other power means for the achievement of combustion at the burner head. The burner head is designed to provide three velocities of fuel and primary air mixture, while means is provided in the manner of a conduit for supplying secondary air under control to the plished.

A more complete understanding of the present invention may be had by means of the following detailed de-' scription taken with reference to the accompanying drawings in which:

FIGURE 1 is a top plan view of the burner, partly in section.

FIGURE 2 is a side elevation of the burner, partly in section.

FIGURE 3 is a diagrammatic side view of a burner installation, showing the resultant flame pattern.

FIGURE 4 is a diagrammatic side view of another burner installation, showing the resultant flame pattern.

FIGURE 5 is a cross sectional elevation of the burner head, in part, taken on line 5-5 of FIGURE 6.

FIGURE 6 is an end view of a burner head taken on line 6 of FIGURE 5.

Like reference numerals refer to like parts throughout the several views, which illustrate a preferred embodiment of the present invention. The embodiment illustrated is particularly well adapted for use as a gas conversion burner for replacement of oil fired burners. Typical of the oil burners being replaced is the so-called guntype burner, where an elongated burner tube is extended through the furnace wall and the flame is forced into a small cubic area, which is sometimes long and narrow.

With reference to FIGURES 1 and 2, there is illustrated a gas burner having an outer cover 11 of substantially cylindrical shape and having a knob 12 on the closed end thereof for facilitating removal of the cover 11. The cover Ill is fastened to the chassis of the burner by means of suitable screws 17. The chassis comprises a chassis ring 14 and a chassis plate 13 fastened together, and all formed of sheet metal or the like. An elongated, substantially cylindrical tubular member forming the secondary air conduit or tube 21 is fastened into the central opening 23 in the chassis plate 13.

This assembly is adapted to be mounted at varying height on suitable supporting legs 18. In this manner, the burner assembly is adapted to be placed at the correct height in front of the opening in the furnace through which an oil burner had been previously installed. The device is also adapted to be mounted by means of an oil burner mounting flange capable of adjustment to the size of the secondary air tube 21 outside diameter.

In the embodiment illustrated, two burner tubes 31 are disposed on a suitable burner drawer plate 22 which is fastened as by welding at its back end to the manifold 46. Angle brackets 16 are welded to the sides of the plate 22 and are secured by means of screws 15 to the chassis plate 13. This serves to rigidly maintain the burner tubes in position within the secondary air tube 21. Safety pilot burner 48 is also fastened to the plate 22, as are the burner tubes 31. The rear end of the burner tubes have disposed therein an adjustable mixer tube. This mixer tube 34 is mounted slidable inwardly and outwardly in the end of the burner tube 31, and is adapted to be locked in any position by means of a suitable lock screw 35. By adjusting the position of the mixer tube 34, the amount of air entering the burner tube 31 may be controlled. The mixer tube 34 has a flared end for the more eflicient mixing of fuel gas and air.

With reference to FIGURES 5 and 6, the burner head 34) is described as comprising the burner tube 31 having an inner sleeve 33 of reduced diameter placed concentrically therein. A corrugated type ribbon sleeve 32 is disposed between the inner sleeve 33 and the burner tube 31. The inner sleeve 33 is positioned at the outer end of the burner head 3%, and is longitudinally shorter than the ribbon sleeve 32.

It is seen that gas and primary air travel through the burner tube 31 in the direction of arrows 1, 2 and 3. The principal volume of this mixture passes through the burner head 35) through the interior of the inner sleeve 33, as indicated by the arrows 1. A secondary volume of principal volume of mixture in opening 1. A third portion of the mixture enters openings 3 between the corrugated sleeve 32and the burner tube 31, and travels at a reduced velocity in relation to the velocity of the second portion.

Combustion air enters the enclosure formed by cover 11 through a space between cover 11 and the adjustable secondary air damper 10, which is supported by means of studs 19 welded to the damper near the forward edge thereof, and extending through slot 20 formed in chassis ring 14. Any conventional lock nut (not shown) threaded to the studs 19 secures the damper in any fixed position. When the burner is installed, the installer 'makes a suitable air intake adjustment by rotating damper 10 inside chassis ring 14 and cover 11, thus varying the size of the opening as required. The damper is then locked in position by means of the lock nuts on studs 19. Secondary air enters the secondary air tube 21 through opening 23 in the chassis 13, and passes out through the outer end of tube 21, at the same time surrounding the two burner heads 30, and providing secondary air to aid in completion of combustion.

It is therefore seen that portion 1 of the gas and primary air constitutes the principal volume of gas-air mixture issuing at maximum velocity from the burner tip or head 30. This first portion is piloted by a proportionately slower second portion issuing from openings 2 at the'burner head at reduced velocity proportionately to the velocity of the first portion. This second portion is likewise piloted by a third portion issuing from openings 3 at the burner head 30 at a reduced velocity proportionately to the velocity of the second portion. The combustion is sustained by the secondary air entering the combustion zone through the tube 21. By this novel apparatus an improved method is presented for the retention of the flame at the burner head.

A flame spreader 24 comprises a plate of heat resistant metal or the like which is specially shaped to deflect the flame so as to form the flame into the substantial shape of a ball or globe. The flame spreader plate 24 is maintained in position in front of the burner heads 30 by means of a suitable rod 25, which is fastened at its other end to the secondary air tube 21. The flame spreader 24 in the present embodiment is substantially as wide as the width of the two burner heads 30. A portion of the flame is divided, FIGURE 5, and the remainder of the flame travels around the spreader 24 in a substantially spherical manner, being piloted by the two reduced velocities of the second and third portions of fuel-air mixture, and the secondary air.

In the operation of the burner, reference is made to FIGURES 3 and 4. The burner is mounted, either by means of the supporting legs 18, or by the oil burner mounting flange 9 in front of a conventional furnace, with the secondary air tube 21 projecting into the combustion zone, the burner heads 30 being inside the tube 21, as hereinbefore described. This is diagrammatically illustrated in FIGURES 3 and 4. FIGURE 3 illustrates operation of the burner using the flame spreader 24. The furnace 6 having refractory brick 7 disposed therein in the conventional manner, it is to be understood that minimum distances between the walls of the combustion zone and the burner head are observed in accordance with standards maintained by those skilled in the art.

The thermostat (not shown) is connected in the conventional manner to the control valve 43, and the control valve 43 is connected to the gas supply by means of inlet pipe 41, and is connected to the pilot burner 48 by means of gas line 49. Pressure regulating valve 42 is placed in the gas line 41 between the source of gas and the control valve 43. This valve 42 regulates the pressure of the gas flow, maintaining an even and constant pressure at all times. As is well known to those skilled in the art, this practice will cause better and more eflicient operation of the burner.

When the thermostat (not shown) indicates the need for heat, the automatic control valve 43 supplies gas to the manifold 46 by means of the valve 43. This gas issues through the orifices 47 from the manifold 46 to the mixer tubes 34, through the burner tubes 31 to the burner heads 30, where the fuel-air mixture is ignited by the pilot flame. Primary air enters the mixer tubes 34 along with the gas from orifices 47 and mixes with In order to produce a flame at the burner head 30 which most efliciently and economically utilizes the gas fuel, the mixer tubes 34 are adjusted so that the head space 36, FIGURE 4, is of the proper size to permit the proper amount of primary air to enter through this head space 36 into the tubes 31. When the mixer tubes 34 are properly adjusted, they are locked in place by means of the lock screw 35. To accomplish this, the outer cover 11 is removed by loosening or removing screw 17 and pulling the cover backwardly by the handle knob 12. This procedure is reversed to replace the outer cover 11 in position.

Should at any time the pilot burner 48 become clogged or otherwise inoperable, or should the burner unit require any kind of service, the entire assembly may be removed from the chassis plate 13, ring 14, and secondary air tube 21 quickly and easily, even while the burner is hot. The outer cover is removed as before, and the screws 15 are removed, loosening the entire burner unit from the rest of the assembly. If rigid gas inlet lines have been used, it will become obvious that the line will have to be disconnected also. The entire burner unit may then be removed from the back end of the chassis plate, as illustrated in FIGURE 2.

An opening, not shown, in the outer cover 11 is provided for the admittance of air into the interior thereof. This air enters the mixer tubes 31 as primary air, and the tube 21 as secondary air for the burner. The opening is adjustable to regulate the amount of air entering the tubes for the purpose of providing more eflicient burning of the fuel, and may be locked open or shut in any desired position by means of a conventional lock screw.

FIGURE 6 illustrates the use of the burner without the flame spreader 24, the refractory brick 7 being used to deflect the flame 8 in the best way to provide efiicient heating. As in the case where the burner is used as a conversion unit from oil to gas, it is well known that oil burner combustion zones are sometimes long and narrow. Therefore, the flame spreader may or may not be used according to the dimensions of the particular combustion zone. In a small combustion area, it is desirable to have minimum flame height, therefore making it desirable to use the flame spreader.

It is seen that the burner heads are substantially the same diameter as the burner tubes. This condition serves to eliminate the building up of static pressures within the tubes, thus eliminating noisy concussion when the flame is extinguished.

It is therefore seen that the leading objects of this invention are best accomplished by the method of placing an inner sleeve of reduced diameter concentrically in the end of the burner head and inserting a corrugated sleeve between the inner sleeve and the burner tube. By making the inner sleeve longitudinally shorter than the corrugated sleeve, a series of ports are formed between the corrugated sleeve and the burner tube which are longitudinally longer than the series of ports between the inner sleeve and the corrugated sleeve. Thus, fuel mixture is issued in its principal volume at maximum velocity through the inner sleeve, at an intermediate velocity through the shorter ports between the inner sleeve and the corrugated sleeve, and at a low velocity between the corrugated sleeve and the burner tube. As hereinbefore described, the principal volume of gas is held piloted by the intermediate velocity portion, and the intermediate velocity portion is held piloted by the low velocity portion.

In summary, some of the advantages of the present invention may be enumerated as follows: (1) All combustion air is conducted by the blast tube to the exact point of use. The air immediately mixes intimately with the fire. In searching for the fire it does not sweep over and cool some of heating surface nor get loose above the fire to dilute the flue gases. This provides maximum efiiciency in a minimum of space. (2) The combination of high velocity burners and the flame spreader produces a concentrated well aerated ball of fire. Lower velocity with an improperly shaped or located spreader would result in a distorted flame pattern. The present invention produces deep down heat transfer well centered in the combustion chamber.

(3) Each of the burner develops a three stage discharge velocity, the inner velocity being highest, and encompassed by an intermediate velocity, and then surrounded by a lower velocity. This provides quiet operation, exceptional pilot stability and excellent aeration.

A particular embodiment of the invention having been described for the purpose of illustration only, it is to be understood that the invention is not to be limited thereto, but is to be construed as fairly falls within the spirit and scope of the appended claims.

We claim:

1. In a burner for gaseous fuel, a pilot burner for igniting said fuel, a burner tube receiving gaseous fuel from an orifice through a mixer tube mounted slidable inwardly and outwardly therein for regulating the primary air entering therein, and a burner head having an inner sleeve of reduced diameter with respect to said tube placed concentrically therein and a corrugated ribbon sleeve disposed between said inner sleeve and said burner tube, said sleeves being positioned at the outer end of said burner head, said inner sleeve being longitudinally shorter than said corrugated sleeve; said burner tube maintained rigidly in position in a secondary air conduit, said inner sleeve in said burner tube defining a first opening therethrough for the issuance of the prin cipal volume of a fuel mixture, second openings being defined between said inner sleeve and said corrugated sleeve for the issuance of said fuel mixture at a reduced velocity with respect to the velocity of said principal volume of said mixture, third openings being defined between said corrugated sleeve and said burner tube for the issuance of said fuel mixture at a reduced velocity with respect to the velocity of said mixture issuing through said second openings, said fuel mixture issuing from said first opening being piloted by said mixture issuing at a reduced velocity from said second openings, and said mixture issuing from said second openings being piloted by said mixture issuing at a further reduced velocity from said third openings; said mixture being ignited by said pilot burner and the resultant flame being supported by secondary air traveling through the secondary air conduit.

2. In a burner for gaseous fuel according to claim 1, a shaped plate maintained in position in front of said burner head for deflecting said flame, whereby maximum turbulence of said flame and rapid completion of combustion is achieved.

3. A burner head for a burner for gaseous fuel, said burner head comprising a burner tube for receiving said gaseous fuel and mixing said fuel with primary air therein, an inner sleeve of reduced diameter mounted con centrically in one end of said burner tube, a corrugated sleeve mounted between said inner sleeve and said end of said burner tube, said inner sleeve being longitudinally shorter than said corrugated sleeve; said inner sleeve forming a first opening therethrough for passing the principal volume of said fuel at maximum velocity, a first series of ports being formed between said inner sleeve and said corrugated sleeve for passing a portion of said fuel at an intermediate velocity, and a second series of ports being formed between said corrugated sleeve and said burner tube for passing a portion of said fuel at low velocity therethrough.

4. In a burner tube for a burner for gaseous fuel, means forming a burner head for said burner tube, said means providing three velocities of said fuel issuing from said burner head, said means comprising an inner sleeve of reduced diameter placed concentrically in one end of said burner tube, a corrugated sleeve placed between said inner sleeve and said burner tube in the end thereof; said corrugated sleeve forming a first series of ports between said inner sleeve and said corrugated sleeve, and a second series of ports between said corrugated sleeve and said burner tube; said inner sleeve being longitudinally shorter than said corrugated sleeve, said second series of ports being longitudinally greater than said first series, said inner sleeve forming an opening therethrough; whereby said fuel is issued from said opening at maximum velocity and through said first series of ports at intermediate velocity and through said second series of ports at low velocity.

References Cited in the file of": this patent UNITED STATES PATENTS 745,872 Machlet Dec. 1, 1903 1,242,992 Sheridan Oct. 16, 1917 1,411,063 Needham Mar. 28, 1922 1,644,610 Reichhelm Oct. 4, 1927 2,121,948 Borland June 28, 1938 2,467,626 Norman Apr. 19, 1949 2,540,308 Weyenberg et a1. Feb. 6, 1951 2,649,777 Saper-sztejn Aug. 25, 1953 2,658,569 Hughes et a1. Nov. 10, 1953 2,858,729 Keyes Nov. 4, 1958 FOREIGN PATENTS 515,433 France Nov. 26, 1920 Add. 23,291 France May 21, 1921

Claims (1)

1. IN A BURNER FOR GASEOUS FUEL, A PILOT BURNER FOR IGNITING SAID FUEL, A BURNER TUBE RECEIVING GASEOUS FUEL FROM AN ORIFICE THROUGH A MIXER TUBE MOUNTED SLIDABLE INWARDLY AND OUTWARDLY THEREIN FOR REGULATING THE PRIMARY AIR ENTERING THEREIN, AND A BURNER HEAD HAVING AN INNER SLEEVE OF REDUCED DIAMETER WITH RESPECT TO SAID TUBE PLACED CONCENTRICALLY THEREIN AND A CORRUGATED RIBBON SLEEVE DISPOSED BETWEEN SAID INNER SLEEVE AND SAID BURNER TUBE, SAID SLEEVES BEING POSITIONED AT THE OUTER END OF SAID BURNER HEAD, SAID INNER SLEEVE BEING LONGITUDINALLY SHORTER THAN SAID CORRUGATED SLEEVE; SAID BURNER TUBE MAINTAINED RIGIDLY IN POSITION IN A SECONDARY AIR CONDUIT, SAID INNER SLEEVE IN SAID BURNER TUBE DEFINING A FIRST OPENING THERETHROUGH FOR THE ISSUANCE OF THE PRINCIPAL VOLUME OF A FUEL MIXTURE, SECOND OPENINGS BEING DEFINED BETWEEN SAID INNER SLEEVE AND SAID CORRUGATED SLEEVE FOR THE ISSUANCE OF SAID FUEL MIXTURE AT A REDUCED VELOCITY WITH RESPECT TO THE VELOCITY OF SAID PRINCIPAL VOLUME OF SAID MIXTURE, THIRD OPENINGS BEING DEFINED BETWEEN SAID CORRUGATED SLEEVE AND SAID BURNER TUBE FOR THE ISSUANCE OF SAID FUEL MIXTURE AT A REDUCED VELOCITY WITH RESPECT TO THE VELOCITY OF SAID MIXTURE ISSUING THROUGH SAID SECOND OPENINGS, SAID FUEL MIXTURE ISSUING FROM SAID FIRST OPENING BEING PILOTED BY SAID MIXTURE ISSUING AT A REDUCED VELOCITY FROM SAID SECOND OPENINGS, AND SAID MIXTURE ISSUING FROM SAID SECOND OPENINGS BEING PILOTED BY SAID MIXTURE ISSUING AT A FURTHER REDUCED VELOCITY FROM SAID THIRD OPENINGS; SAID MIXTURE BEING IGNITED BY SAID PILOT BURNER AND THE RESULTANT FLAME BEING SUPPORTED BY SECONDARY AIR TRAVELING THROUGH THE SECONDARY AIR CONDUIT.

Images