US3929290A

US3929290A - Fuel atomizer

Info

Publication number: US3929290A
Application number: US513682A
Authority: US
Inventors: James F Tallarovic
Original assignee: Babcock and Wilcox Co
Current assignee: Babcock and Wilcox Co
Priority date: 1974-10-10
Filing date: 1974-10-10
Publication date: 1975-12-30
Anticipated expiration: 1992-12-30
Also published as: NL179679B; JPS5164643A; AU8562575A; NL7511949A; GB1517005A; ZA756398B; AR204473A1; JPS5646052B2; CA1036925A; BR7506664A; AU497771B2; NL179679C

Abstract

An improved burner for use with sediment containing liquid fuel and including an atomizer having plate means for promoting fuel flow prior to the atomization thereof.

Description

United States Patent 1191 1111 3,929,290

Tallarovic Dec. 30, 1975 [5 FUEL ATOMIZER 724,053 3/1903 Schroeder 239 4173 1,300,643 41919 'P 239 417.3 [75] memo James Tanarovlc, Cmcmnatr 2,643,916 6/1953 et a1. 239/4165 01119 3,215,352 11 1965 Meraz, Jr 239/416 x [73] Assignee: The Babcock & Wilcox Company,

New York Primary Examiner-John J. Love 22 Filed; ()CL 0 1 7 Assistant Examiner-Michael Mar Attorney, Agent, or FirmJ. Maguire; R. J. Edwards [21] Appl. No.: 513,682

[52] US. Cl. 239/4173; 239/432; 239/423 [57] ABSTRACT [51] Int. Cl. B05B 1/30 58 Field 61 Search 239/4173, 416, 416.4, An improved burner for use Wlth Sediment wntammg 239/41 5 423 424 432 liquid fuel and including an atomizer having plate means for promoting fuel flow prior to the atomization [56] References Cited thereof N1 U TED ST ATES PATENTS 7 Claims, 2 Drawing Figures 714,394 11/1902 Pfe1ffer et a1. 239/4173 X FUEL ATOMIZER BACKGROUND OF THE INVENTION The invention relates to fuel burners, and more particularly to a liquid fuel burner equipped with an atomizer capable of vapor atomizing sediment containing liquid fuels without pluggage of the fuel passages.

Fluid assist atomizers have been successfully used for some time. For example, U.S. Pat. No. 3,650,476, issued on Mar. 21, 1972 in the name of Rackley et al and assigned to the assignee of the present invention, discloses an atomizer having three stages of atomization. The first stage occurs as the fuel stream is sheared by high velocity vapor, the second is the impingement and redirecting of the fluid mixture discharging from the first stage, and the third stage takes place as the fluid mixture is expanded while passing through the burner discharge ports.

The first stage of atomization for the burner discosed in U.S. Pat. No. 3,650,476 includes a plurality of radial ports which divide the liquid fuel into individual streams to be sheared by the atomizing vapor. In order to obtain maximum shearing effect, the ports lie normal to the fuel and vapor inlet passages. Use of this type atomizer with sediment containing fuels such as refinery pitch, tar, asphalt, etc. is proving less than satisfactory due to frequent pluggages occuring at the point where the fuel flow path turns 90 as it enters the radial ports. This change in direction causes the heavier particles in the fuel to settle in the forward end of the fuel passage and results in eventual blockage of the radial ports.

SUMMARY OF THE INVENTION The present invention provides a liquid fuel burner for use with sediment containing fuels and including an improved atomizer comprising a cylindrical member having a first passageway means in the form of a center bore for fuel flow and a second passageway means in the form of a plurality of conduits for atomizing vapor flow, the latter being orbitally disposed about the center bore. The atomizer is fitted with a perforated end cap for discharging atomized fuel from the burner, and includes a pair of orifice plates interposed between the cylindrical member and the end cap.

In accordance with the invention, the atomizer includes a deflector having plate means cooperating with the cylindrical member to define therebetween an annular outlet for discharging fuel into the atomizing vapor exiting from the conduits. The plate means is of circular radial cross section and has a diameter slightly less than the diameter of the inner circle formed by the orbitally disposed conduits so as not to interfere with the atomizing vapor exiting from the conduits. The plate means surface which defines one side of the annular outlet is of arcuate configuration and projects into the center bore to guide and promote the flow of fuel as it turns 90 on its way to being discharged from the first passageway means. The deflector includes a shank extending from the plate means and having its distal end projecting through the atomizer end cap and being supported therefrom. The shank is rotatably engaged with the end cap to permit axial adjustment of the deflector thereby providing the means for changing the cross sectional flow area of the annular outlet to optimize the discharge of a particular fuel.

In the main embodiment, the deflector shank is weldably secured to the atomizer end cap to maintain the position which has been determined as the optimum annular outlet flow area for a particular fuel.

In an alternate embodiment, the selected annular outlet flow area is being maintained by threading a locknut onto the shank and tightening against the atomizer end cap to secure the deflector thereto. Whenever an adjustment in the annular outlet flow area is required to accommodate a change in fuel or fuel characteristic, the locknut is loosened to allow repositioning of the deflector and is thereafter tightened to secure the deflector in the newly selected position.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side view of the liquid fuel burner including a main embodiment of the atomizer of the present invention.

FIG. 2 is a sectional side view of an alternate embodiment of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION Referring to FIGS. 1 and 2, there are shown a liquid fuel burner 10 comprising a barrel 12 threadably engaged at one end thereof to a coupling 14 and at the other end to a sleeve 16, the latter being in turn threadably engaged to a sprayer cap 18. The coupling 14 is provided with a peripheral passageway 20 which admits the liquid fuel to the burner 10. The passageway 20 discharges into a tube 24, the latter being threadably engaged to an inner wall portion of the coupling 14 and including a seal ring 25 welded to the tube 24 and abutting against the penetrated inner wall so as to maintain the tube 24 in a fixed position and provide a leak-proof junction at the point of penetration. The tube 24, which defines a central passageway 26, extends through a major portion of the burner 10 and includes a telescoped forward section 27 which engages a cylindrical member 30), the latter forming part of the atomizer 31 of the present invention.

The coupling 14 is provided with a central passageway 22 which admits atomizing vapor to the burner 10 and discharges it into an annular passageway 28 formed by the tube 24 and the barrel l2 and a portion of coupling 14.

The cylindrical member 30 includes a center bore 32 extending therethrough and communicating with the central passageway 26, and a plurality of equispaced conduits 36 extending through the member 30 in parallel and spaced surrounding relaltion to the center bore 32, and communicating with the annular passageway 28.

The center bore 32 extends through the cylindrical member 30 in coaxial relation therewith and is comprised of an inlet segment 37 and an outlet segment 38, the two segments being joined by a uniformly convergent transition segment 40. The inlet segment 37 is of uniform cross section throughout and is sized so as to slidably engage the forward end section 27 of tube 24. The outlet segment 38 has a smaller cross sectional diameter than the inlet segment 37 and has an inwardly tapered leading end portion 41.

The conduits 36 are of equal dimension and of uniform cross section throughout. A pair of

orifice plates

42 and 44 respectively are disposed adjacent the discharge end face 45 of cylindrical member 30. The

orifice plates

42 and 44 are formed with respective 3

passageways

46 and 48 of frusto-conical configuration Whose small ends abut one another and are formed with a straight edge so as to define a cylindrical passageway 49 intermediate the two frusto-

conical passageways

46 and 48.

The sprayer cap 18 is comprised of a cylindrical wall 50 openat one end, and closed at the other end by a central wall 52 lying along a plane normal to the burner axis and a perforated inclined wall 54 disposed intermediate the

walls

50 and 52. The cylindrical wall 50 is formed with an internal thread which engages complementary threads on the sleeve 16, and includes a shoulder that abuts the leading face of orifice plate 44 to maintain it and the orifice plate 42 in a fixed position. A chamber 56 is formed between the orifice plate 44 and the front end of the sprayer cap 18. The chamber 56 discharges through a plurality of openings 58 which extend through the wall 54 in a direction normal thereto.

In accordance with the invention, an atomizer 31 is provided with a deflector 60 having at one end thereof a plate means 62 and at the other end a shank 64, the latter being supportingly connected to the atomizer end cap 18. The plate means 62 includes a cylindrical segment 66 having an end face 68 formed with an arcuate surface projecting into the tapered bore portion 41 and cooperating therewith and with the end face 45 of cylindrical member to define therebetween an annular outlet 70. The segment 66 merges into a frusto-conical segment 72 which in turn merges into the shank 64, the latter being of cylindrical shape and having a threaded portion-74 which rotatably engages complementary threads formed along the opening 76 of the end capcentral wall 52. The threaded portion 74 has a predetermined length to permit an adjustment in the position of deflector 60 along the burner axis thereby providing the means for changing the cross sectional flow area of the annular outlet 70. The adjustment is effected by inserting a screwdriver (not shown) in the slot 78, formed on the end face of shank 64, and rotating it in a clockwise direction to reduce the flow area of the outlet 70, and in a counter-clockwise direction to increase the flow area of the outlet 70.

In accordance with the main embodiment of the invention, when the desired cross sectional flow area for the annular outlet 70 has been obtained, a weldment'80 is applied between the exposed end of shank 64 and the central wall 52 to fixedly secure the deflector 60 to the atomizer end cap 18.

In accordance with the alternate embodiment of the invention, a locknut 82 is threaded onto the exposed portion of the shank 64. When the desired cross sectional flow area for the annular outlet 70 has been obtained, a wrench (not shown) is applied to the locknut 82 to tighten it against the central wall 52 thereby securing the deflector 60 to the atomizer end cap 18. If a change is required in the cross sectional flow area of the outlet 70, the locknut is loosened to allow repositioning of the deflector 60, and is thereafter tightened to secure the deflector 60 in the newly selected position.

During operation of the burner 10, pressurized liquid fuel, e.g. oil, is continuously supplied to the coupling 14 for serial flow through the

passageways

20 and 26 and the center bore 32. At the same time, atomized vapor, e.g. steam, is pressurized to a level higher than that of the fuel and is continuously supplied to the coupling 14 for serial flow through the

passageways

22 and 28 and the conduits 36. The jets of steam exiting from the conduits 36 shear the -oil stream being discharged from the annular outlet 70. In accordance with the invention, the annular outlet includes a tapered portion 41 which cooperates with the arcuate surface of the plate means end face68 to promote fuel flow through the turn defined by the annular outlet 70. Moreover, the deflector 60 is rotatably adjustable to change the cross sectional flow area of the annular outlet 70 thereby providing optimum clearaance as the fuel path turns 90 prior to discharge into passageway 46.

The atomized fuel-vapor mixture, while still above atmospheric pressure, if further atomized as a result of pressure and velocity energy change during flow through the passageway 49 formed by

orifice plates

42 and 44. The atomized fuel-vapor mixture is then passed to the chamber 56 and is thereafter discharged through the openings 58 where pressure energy is further converted to velocity energy. The resultant expansion of steam causes still further break-up of the liquid fuel into small particles with intimate mixing of the fuel and steam with the result that a substantially homogeneous mixture of finely atomized fuel and steam is produced for subsequent introduction in the combustion air stream. 1

While in accordance withthe provisions of the statutes there is illustrated and described herein a specific embodiment of the invention, those skilled in the art will understand that changes may be made in the form of the invention covered by the claims and that certain features of the invention may sometimes be used to advantage without a corresponding use of the other features.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows: 1

1. A liquid fuel burner having tube means defining a central passageway, barrel means concentrically disposed abcut said tube means to form therebetween an annular passageway, means supplying a fluid to be atomized to said central passageway and an atomizing fluid to said annular passageway, the improvement comprising an atomizer connected to the barrel means, said atomizer including a cylindrical member having a first and second passageway means communicating respectively with said central and annular passageways, a perforated end cap for discharging the atomized fluid from said burner, and a deflector having plate means cooperating with an end face of the cylindrical member to form therebetween an annular outlet passageway from said first passageway means the plate means including an arcuate projection facing said first passageway means, and, the deflector being mounted on said cap.

2. The liquid fuel burner according to claim 1 wherein the annular outlet passageway includes at least aportion thereof tapered in the direction of discharge from said first passageway means.

3. The liquid fuel burner according to claim 1 including the deflector being fixedly mounted on said end cap. 7

4. The liquid fuel burner according to claim 1 including the deflector being movably mounted on said end cap. r v I 5. The liquid fuel burner according to claim 1 wherein the deflector includes a shank extending through said end cap and being supported therefrom.

3,929,290 6 6. The liquid fuel burner according to claim 5 includ- 7. The liquid fuel burner according to claim 6 including the end cap and shank having threaded portions ing means engaging the threaded shank portion to secooperating with one another to permit axial movecure the deflector to said end cap. ment of said deflector. 5

Claims

1. A liquid fuel burner having tube means defining a central passageway, barrel means concentrically disposed about said tube means to form therebetween an annular passageway, means supplying a fluid to be atomized to said central passageway and an atomizing fluid to said annular passageway, the improvement comprising an atomizer connected to the barrel means, said atomizer including a cylindrical member having a first and second passageway means communicating respectively with said central and annular passageways, a perforated end cap for discharging the atomized fluid from said burner, and a deflector having plate means cooperating with an end face of the cylindrical member to form therebetween an annular outlet passageway from said first passageway means the plate means including an arcuate projection facing said first passageway means, and, the deflector being mounted on said cap.

2. The liquid fuel burner according to claim 1 wherein the annular outlet passageway includes at least a portion thereof tapered in the direction of discharge from said first passageway means.

3. The liquid fuel burner according to claim 1 including the deflector being fixedly mounted on said end cap.

4. The liquid fuel burner according to claim 1 including the deflector being movably mounted on said end cap.

5. The liquid fuel burner according to claim 1 wherein the deflector includes a shank extending through said end cap and being supported therefrom.

6. The liquid fuel burner according to claim 5 including the end cap and shank having threaded portions cooperating with one another to permit axial movement of said deflector.

7. The liquid fuel burner according to claim 6 including means engaging the threaded shank portion to secure the deflector to said end cap.