US3850571A

US3850571A - High energy flame burner

Info

Publication number: US3850571A
Application number: US00305236A
Authority: US
Inventors: J Zink; R Reed
Original assignee: John Zink Co
Current assignee: KGI Inc
Priority date: 1972-11-10
Filing date: 1972-11-10
Publication date: 1974-11-26
Anticipated expiration: 1991-11-26

Abstract

There are many applications in the art of burning fuels, where it is much preferred that the flame produced as the fuel burns be as a long, slender, rod-like, stiff, high-velocity, or highenergy jet of flame of small diameter, and preferably of maximum length. This invention describes the type of burner which will provide a stable, long, rod-like flame of this type. It consists of a fuel pipe with a rounded closed end. One or more principal orifices are placed symmetrically on, or about, the axis of the pipe. The principal flow of gas is through these principal orifices, and the fuel under proper pressure in the pipe will be discharged in a long, slender, high-velocity jet of fuel. In addition, there are secondary jets which issue from the pipe through secondary orifices at an angle to the axis. On mixing with air, these secondary jets of fuel provide a ring of flame encasing the principal jet of fuel so as to assist in the ignition of the gas in the principal jet, and prevent it from being blown out due to the high velocity of the jet.

Description

United States Patent 1191 Zink et al. .Nov. 26, 1974 HIGH ENERGYFLAME BURNER [75] Inventors: John S. Zink; Robert D. Reed, both [57] ABSTRACT of Tulsa, Okla.

There are many applications 1n the art of burning Assighee? John Zink p y Tulsa, Oklafuels, where it is much preferred that the flame pro- [22] Filed; 0 1972 duced as the fuel burns be as a long, slender, rod-like, stiff, high-velocity, or high-energy jet of flame of small PP 305,236 diameter, and preferably of maximum length. This invention describes the type of burner which will pro- [52 US. (:1 431/349, 239/423, 239/425.5 a Stable, long, rod-like flame of this yp H9911- [511 1111. C1. F23d 13/36 Sists of a fuel P with a rounded Closed One or [58] Field of Search 431 /349; more Primipal orifices are Placed symmetrically 239/423 425 5 or about, the axis of the pipe. The principal flow of gas is through these principal orifices, and the fuel 56] References Cited under proper pressure in the pipe will be discharged in UNITED STATES PATENTS a long, slender, high-velocity jet of fuel. In addition, there are secondary jets which issue from the pipe 1,884,764 lO/l932 Lonergan 431/349 through Secondary orifices at an angle o the axis o $3224 8? 22:? Ziggy; mixing with air, these secondary jets of fuel provide a 2 784 778 3/1957 1141115511,: 2:11:11: 431/349 'lq the prinfipal jet 9 f as to 3:002:553 lO/l96l Reed 431 /349 the ghlhoh of the gas the PhhclPal and Primary Examiner-Carroll B. Dority, Jr. Assistant Examiner-Larry l. Schwartz Attorney, Agent, or Firm-Head & Johnson prevent it from being blown out due to the high velocity of the jet.

4 Claims, 12 Drawing Figures nv 6|974 PATENTEL U 2 sum 2 OF 2 HIGH ENERGY FLAME BURNER BACKGROUND OF THE INVENTION FIGS. 4 and 5 illustrate respective top plan and sectional views of another embodiment.

FIGS. 6 and 7 represent a further embodiment.

FIGS. 8, 9, and 10 illustrate three forms of the flame This invention is in the field of burners for the com- 5 that will be provided by the burners respectively shown bustion of fuel. More particularly, this invention involves the burning of fuel in the form of long, rod-like jets of flame, which extend for a considerable distance beyond the burner, and are of small diameter.

There are many examples where the flame produced by the burning of fuel is desired in the form of long, rod-like, high-velocity, high-energy jets of flames, of small diameter, and of considerable length. Such flames can be extremely useful either in furnaces or flare type burners. However, prior art devices have not produced flames suitably long or of small enough diameter, and of adequate stiffness or direction of the jet, or of sufficient energy in the forward movement of the fuel discharge. In the prior art devices, the flames have generally been unstable because of their high velocity and the consequent danger of the flame being extinguished because of the rapid velocity of the fuel.

SUMMARY OF THE INVENTION It is a principal object of this invention to provide a type of burner which can be used to produce long, rodlike, stiff high-velocity, small diameter flames for the combustion of fuel.

More particularly, it is an object to provide such a burner that will be completely stable, even though the diameter of the issuing flame is reduced and its length increased. 7

These and other objects are realized and the limitations of the prior art are overcome in this invention by designing a burner which has a principal orifice, directed either axially or angularly of the fuel pipe, which under adquate fuel supply pressure creates a very high velocity jet of fuel. Such a jet of fuel can only burn from the outside and consequently it retains the same shape as a flame, as the jet of fuel. It becomes important therefore to provide a continuing stable ring of flame around the jet, so that the fuel in the jet can be ignited and combustion carried on throughout the length of the fuel jet. The igniting flame is provided by a series of small secondary orifices directed at an angle, outwardly from the axis of the pipe of 45 to 60 or more degrees. These small jets are adequately mixed with air and ignited to provide a stable flame, completely surrounding the jet of fuel. Thus, as the jet emerges from the principal orifice and entrains air along its outer surface, the mixture of fuel and air will be ignited and the flame will be a stable one since there will be continuous ignition of the fuel at the base of the high speed jet.

BRIEF DESCRIPTION OF THE DRAWINGS These and other objects of this invention and a better understanding of the principles and details of the invention will be evident from the following description taken in conjunction with the appended drawings, in which:

FIG. 1 illustrates a top plan view of one embodiment of this invention.

FIG. 2 is a sectional view along the line 22 of FIG. 1.

FIG. 3 is a sectional view along the line 33 of FIG.

in FIGS. 1, 2 and 3, FIGS. 4 and 5, and FIGS. 6 and 7.

FIGS. 11 and 12 show a further variation of the invention.

The preferred embodiment is shown in FIGS. 1, 2 and 3. FIG. 1 is an end view of the burner generally indicated as numeral 10. FIG. 2 is a cross section taken along the line 2'-2 of FIG. 1, while FIG. 3 is a cross section taken along the line 3-3 of FIG. 2. The burner comprises a pipe 12 with a rounded end 22 and with a primary, central, axial opening 20 surrounded by secondary openings 21 through which the fuel passes. The fuel can be a gas or an atomized liquid fuel. In all cases the pressure upstream of the discharge ports is greater than atmospheric pressure. The flame length isroughly proportional to the square root of the pressure drop across the discharge ports. However, the flame diameter is substantially constant as the length is changed by pressure variation. Any upstream pressure may be used, and critical discharge velocity does not alter the performance of this burner. There are a plurality of smaller tertiary openings 30, circumferentially spaced around the pipe below its end, discharging into an annular space 15 between the pipe and a cylinder 14. There are a series of openings 18 circumferentially spaced around the base 16 of the cone 14. Fuel travels generally axially in the space 32 inside of the pipe in accordance with arrows 22. The principal portion of this fuel goes by way of arrows 24 out through the primary and

secondary openings

20 and 21 in a generally axial direction in accordance with the arrows 25. A small part of the fuel goes by way of arrows 23 through the tertiary openings 30 into the annular space 15 and deflected as shown. Air outside conduit 12 is induced into the annular space 15 through the openings 18 in accordance with arrows 28. The air and gas mix in the annulus and are ignited by means not shown but well known in the art, and provide a continuing stable flame in accordance with the arrows 29 which act to maintain ignition of the fuel issuing from

ports

20 and 21.

As the jet of fuel, which for convenience we will discuss as if it were a gaseous fuel, issues from the

openings

20 and 21 at high velocity, the pressure at the periphery of the gas jet will be lower than atmospheric. Air will be drawn in radially along the sides of the jet to mix with the outer layer of the fuel. Similarly the issuing jets of flame from the annulus 15 which surround the column of the jet of fuel will be drawn radially inward and will ignite the fuel in the jet and the air mixing with it. Thus, the high velocity jet now will be ignited and continuing ignition will be maintained at the point of issuance of the fuel, and beyond, by means of the stable flame generated by the flow of fuel and gas through the annulus 15. Thus by using a high enough pressure of the fuel in the space 32, and thereby getting a high enough velocity if jet issuing from

orifices

20 and 21, a flame of great length and narrow cross section can be provided which is continuously ignited as it issues from the burner its stability enhanced by the tertiary air-gas mixture at 29.

The embodiment shown in FIGS. 1, 2 and 3 is preferred since the igniting flame according to arrows 29 is the most effective. As the pressure inside the fuel pipe increases, the velocity of the issuing jet increases and the length of the resulting flame increases, although the diameter of the flame does not vary significantly.

Consider now the embodiment of FIGS. 4 and 5. Pipe 37 with the rounded end 38 is provided with a large axial port 40, through which the gas flow 46 emerges, in accordance with the arrow 48, at high velocity and directed along the axis of the pipe. There are a plurality of smaller secondary orifices 50 surrounding the main orifice 40. These are directed at an angle A which may vary from 45 to 60. The gas issuing through the small orifices 50 in accordance with arrows 45 is ignited at the outside of the pipe and provide a stable flame which is used in one embodiment to continuously ignite the jet of fuel gas as it emerges at high velocity from the orifice 40. In FIGS. 6 and 7 there is a slight variation, which is shown in the use of a plurality of smaller principal orifices 52, which, however, have substantially the same total area as the orifice 40. Here again, the gas issuing through the secondaryorifices 50 provide fuel for a stable flame which is used to ignite the continually issuing high velocity jet of fuel.

The type of flames involved with each of these three embodiments of burner are shown respectively in FIGS. 8, 9 and 10. FIG. 8 shows the flame that is provided by the type of burner in FIGS. 1, 2 and 3, while FIG. 9 shows a similar flame which would be provided by the burner of FIGS. 4 and 5. FIG. 10 shows the flame issuing from the burner of FIGS. 6 and 7. In genera] the flame 70 of FIG. 10 will be shorter and wider than the other two flames because of the multiple orifices 52. These will cause some air inspiration into the interior of the flame where combustion will take place, causing an externally directed pressure which will tend to widen the jet and the resulting flame. As a consequence the flame will be shorter and wider. In FIGS. 6 and 7 the secondary jets issuing through openings 50 will have an exit angle B which is in the range of 45 to 60 and which may be as great as 90. In some instances, additional stabilization is provided by diverting a portion of the gas through transverse or tertiary openings 30 into the annular space formed by diversion baffle 14A. Air is induced into the space 15 through openings 18 and upon ignition provides a continuing flame to maintain the primary and secondary flames stable.

A principal advantage of this invention is its ability to produce the preferred flame configuration stably when velocity of flow of fuel from the orifice is some or critical. Sonic or critical velocity exists in flows across ports or orifices when the absolute pressure upstream of the port or orifice is twice the absolute pressure downstream of the orifice. Flow velocities may range from 600 feet per second to more than 4,200 feet per second at the critical or sonic state, according to the specific nature of the fuel. Since the minimal velocity can thus far exceed published rates for flame propagation, this invention is genuinely unique as a means for generating small diameter, rod-like flames when initial flow velocity of the fuel-like flame is sonic, and where there is stable burning for the entire length of the flame.

In FIGS. 1-7 the

principal gas orifices

20, 40, and 52 are all shown as being directed along the axis of the burner pipe 37. It will be clear that the burner pipe can be installed in any desired direction to correspondingly direct the flame in the same direction.

In FIGS. 11, 12 is shown a variation of the burner of FIGS. 4 and 5, in which the principal orifice 40 is at an angle to the axis of the burner pipe 37. While an angle of 45 is shown, the angle of the orifice with reference to the axis of the pipe can be any desired angle, from 0 to 60 or more. Also, the small orifices 50 which surround the orifice 40, are repositioned so as to surround and be at a desired angle (such as 45) to the principal orifice 40. Although not shown the

diversion baffle

14 or 14A previously shown is adaptable to the embodiment of FIGS. 11 and 12. In some instances only a partial circular baffle is necessary adjacent the side the flame is directed.

While the invention has been described with a certain degree of particularity it is manifest that many changes may be made in the details of construction and the arrangement of components. It is understood that the invention is not to be limited to the specific embodiments set forth herein by way of exemplifying the invention,

but the invention is to be limited only by the scope of r the attached claim or claims, including the full range of equivalency to which each element or step thereof is entitled. 4

What is claimed:

l. A burner producing a long, small diameter, rodlike flame, comprising:

a. a pipe for carrying fuel at greater than atmospheric pressure;

b. at least one primary fuel discharge orifice of selected area at the distal end;

c. a plurality of smaller secondary openings arranged around said primary orifice and directed laterally outward;

d. a plurality of smaller tertiary orifices arranged upstream of said secondary openings to direct a minor fraction of the total fuel approximately perpendicular to the axis of said pipe; and

e. a diversion baffle having a downstream end located between said secondary and tertiary orifices, said baffle forming an annulus space opposite said tertiary orifices, and a plurality of openings in said baffle to direct inspirated air into said annulus space.

2. The burner as in claim 1 including a plurality of primary orifices arranged symmetrically in the closed end of said pipe, the total area of said plurality of orifices substantially equal to said selected area.

3. The burner as in claim 1 in which the direction of said primary and secondary orifices is at an angle of 45 to from the axis of the pipe.

4. The burner as in claim 1 in which said distal end is substantially hemispherical.

Claims

1. A burner producing a long, small diameter, rod-like flame, comprising: a. a pipe for carrying fuel at greater than atmospheric pressure; b. at least one primary fuel discharge orifice of selected area at the distal end; c. a plurality of smaller secondary openings arranged around said primary orifice and directed laterally outward; d. a plurality of smaller tertiary orifices arranged upstream of said secondary openings to direct a minor fraction of the total fuel approximately perpendicular to the axis of said pipe; and e. a diversion baffle having a downstream end located between said secondary and tertiary orifices, said baffle forming an annulus space opposite said tertiary orifices, and a plurality of openings in said baffle to direct inspirated air into said annulus space.

3. The burner as in claim 1 in which the direction of said primary and secondary orifices is at an angle of 45* to 90* from the axis of the pipe.