US1446746A - Fuel burner - Google Patents

Description

E. HOXIE.

FUEL BURNER.

FILED MAR`2,1921.

Feb. 27, 1923.

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" u Nid Ha I?? ve Y? Z242' Patented Feb. 27, 1923.

UNITED ,STATES EDMUND HOXIE, OF SOMERVILLE, MASSACHUSETTS.

FUEL BURNER.

'Application fuea Marh 2, 1921. sriai No. 449,051.

To all whom t may concern:

Be it known that EDMUND Hox1n,a citizen of the United States, and resident of Somerville, in the county of Middlesex and State of MassachusettsLhas invented new and useful Improvements in Fuel Burners, of which the following is a specification.

This invention relates to devices for use in connection With the 4burning of liquid or gaseous fuel and more particularly to a carbureting device intended to supply a suitable mixture `of suoli fuel with air or other oxidizing agent under pressure for heating metallurgical or other furnaces, forges, muffles, kilns and in fact any lheat generating device wherein liquid or other mobile fuel may be utilized and Wherea supply of air, steam, or other gaseous fiuld under pressure is available.

In the use of liquid or gaseous fuel it is highly important from the standpoint of economical use as well as in the attainment of high degrees of temperature that the fuel be mingled with air 'or other oxidizing medium in sufficient quantity to assure complete combustion. Unless however the fuel is very thoroughly subdivided and reduced to a mist-like form, if not actually gasified, before it is burned, it is impossible to obtain the best results even though the proper quantity of oxygenbe supplied, and in many burner devices as at present constructed such thorough breaking 4up of .the fuel and its mixture'with air is very imperfectly attained.

One object of the present invention is to provide for the effective admixture of liquid or gaseous fuel with air whereby such fuel may be rthoroughly broken up and reduced to a mist-like form or vapor whose particles shall be intermingled with and suspended in a suitable quantity of air to promote completel combustion. A s one mode of attaining this object the fuel may be admitted to a stream of air or other gaseous fluid under pressure and such stream with the fuel carried thereby may be permitted to enter an expandin chamber wherein the particles of fuel may e permitted to impinge violently against a suitable bafiie or deflector member whereby the droplets of fuel are completely broken up and by reason of the eddies formed in the expansion chamber are thoroughly mixed lwith such gaseous fluid. In connection with this arrangement, if desired, the fuel may be admitted to the pressure fluid stream by inspirator means comprising a Venturi tube.

In the employment of gaseous fiuid under pressure as a means for supplying fuel to a burner, it is undesirable to employ such fluid in sufficient quantity to promote complete combustion of the fuel as the quantity necessary for such purpose is relatively great and makes 'the use of a burner so supplied with the necessary oxidizing agent unnecessarily expensive.

If the pressure fluid employed be air, the cooling effect' o-f thel necessary quantity thereof in expanding from high pressure is undesirable as it tends to lower the temperature of the furnace to a substantial degree. Furthermore, when it is attempted to employ such a large volume of compressed air, diiculty is experienced from the presence of condensed Water in the blower pipe. Under some circumstances water may accumulate in sufficient quantity to extinguish the flame in the furnace, and even when in smaller amount such water neces sarily results in a lowering of the furnace temperature. If steam under pressure be employed4 as the fuel conveying medium, similarly undesirable results are attained and incomplete combustion of the fuel results. Moreover, in manyinstances, for example in forges, muffles, etc., it is undesirable to have the mingled air and fuel admitted in a b-lastof such intensity as results from the direct use of air under the usual pressures employed in industrial establishments.

A further object of the invention is to provide a device whereby a relatively small quantity of a gaseous medium under high pressure may be employed for breaking up the fuel into proper form for burning and if desired for producing an inspirating action in the fuel pipe, while at the same time serving to induce the flow of ay relatively large quantity of airA at atmospheric pressure and temperature -for properly diluting the mingled fuel and highcpressure fluid.

- To. this end the mingledI fuel and gaseous.` fluid under pressure may, after mixing, be delivered from a suitablejnozzle intoan airv inspirator comprising free Aairzinletsvand a chamber having converging wallswhereby the stream of yfuel and pressure fluid servesl to induce the flow through such inlets of` relatively `large volumes of atmospheric air.,y

While in most cases compressed air would be employed as the fuel conveyiip, medium it is evident that other-gaseous uids such as steam or combustible gas under pressure vmight be employed. With the present arrangement, if steam is used the relatively small quantity of steam admitted -to the furnace is of little consequence so far as its moisture content is concerned while any heat resulting from condensation of the steam is merely transferred to the fuel and air so that no loss of heat takes place.

n the following description, the term air has been employed as indicative of va suitable pressure fluid for conveying the particles of fuel, but it is t0 be understood that air is referred to merely as illustrative of a desirable means for attaining the desired end and that any other fluid medium such as steam under pressure or gas might be employed for the purpose. It is also clear that while primarily intended for use with liquid fuel, the apparatus herein disclosed, might, with littlechange be used for the feeding o-f gaseous or4 even pulverized solid fuel. Moreover while primarily intended as a fuel burner, the device is equally efficacious as a blower whereby, by the use of a relatively small .amount of pressure fluid such as compressed air, a. large quantity of free or atmospheric air can be induced to flow through the delivery tube. When so employed little or no diflicultyl is experienced from the presence of small quantities of condensed moisture in the pressure fluid, although such moisture has, in connection with the use of air operated blowers such as heretofore known, been a constant source of annoyance and inefliciency.

A.` preferred arrangement for carrying into effect the above objects is illustrated in the accompanying drawings, in which F ig.1 is a longitudinal cross section of a device particularly adapted to serve as a burner for use in a rivet heating forge;

Fig. 2 is a transverse cross section on the line 2.-2 of Fig. 1;

Fig. 3 is a similar cross section on the` line 3-3 of Fig. 1;

Fig. 4 is a cross section on the line 4 4 of Fig. 1;

Fig. 5 is a cross section on the line 5-5 of Fig. 1;

Fig. 6 is a fragmentary longitudinal cross section to enlarged scale of a portion of the device shown in Fig. 1 and illustrating diagrammatically the. path of the fluid passing through the mixing chamber; and

Fig. 7 is a longitudinal cross section of a modified element useful in connection with a device such as shown in Fig. 1.

Referring to Fig. 1 a' composite casing having suitable passages therein for fuel and air is shown having at 1 a connection to which may be secured the delivery end 2 of a supply pipe for compressed air. This connection has an internally screw threaded portion as at 3 for engagement with a flange member 4 projecting outwardly from a block 5. Extending longitudinally through the block 5 are a pair of channels or passages 6 through which air under pressure may pass from the pipe 2 to the left-hand side of the block 5. Centrally of the block 5 is formed a chamber 7 which is internally screw threaded at 8 for the reception of a pipe 9, such pipe leading from any1 suitable source of liquid fuel. y Extending laterally from the chamber 7 is apassage 1() which extends through a projection 11 at the left-hand side of the block 5, such projection being of substantially cylindrical form and tapering in diameter at its outer extremity wherethe passage 10 termina-tes in a nozzle opening 12.

The block 5 is provided at its left-hand end with an outstanding flange 13 internally screw threaded for engagement with a nipple 14 extending outwardly fro-m a support 15. The space 16 within` the'nipple 14 forms achamber into which the: air is delivered from the passages 6, the left-hand wall of su-ch chamber being formed by the end of a plug 17 seated in a suitable bore in the support 15. The block 17 has a longitudinal passage 18 which at its right-hand portion is of substantially conical form and into which projects the nozzleend of the member 11. At its left-hand portion the member 17 is provided with an extension 19 having therein a cylindrical. bore 20 forming a continuation of the passage 18, such bore terminating in a delivery opening or nozzle at 21.

The extension 19 is preferably externally screw threaded, and engaging with such screw threaded portion is a sleeve member 22, such sleeve memben being arranged to provide a chamber 23 at the left hand end of the extension member 19. The left-hand wall of the chamber 23 comprises a substantially conical surface at 24, .the apex of which 1s directed toward the opening -21. From the base of such conical surface extend a plu-y rality of diverging passages 25 suitably spaced apart, and together constituting a discharge nozzle.

The support 15 has extending therefrom -a series of spider arms 15a, 15b, etc., such In the normal operation of the device as described. air under high pressure is admitted through the pipe 2 and flowing through the passages 6 is admitted to the chamber 16. At the Sametime liquid fuel is caused to flow by gravity or in other suitable manner into the chamber 7 and thence out through the nozzle opening at 12 into the conical passage 18. In tlus passage it is picked up by the rapidly flowing stream of air and carried through 'the passage 20 where it is discharged at the opening 21 into the chamber 23. As the stream of air and fuel emerges into the enlarged space 23, it is caused to impinge with great violence upon the opposite wall of the chamber as indicated diagrammatically in Fig. 6. Any droplets of fuel of substantial size which may be carried by the air stream are thus broken up into extremely fine particles and as the sudden change of direction of the fluid in the chamber 23 results in the formation of eddies therein such as indicated at A, B, such particles are thoroughly mixed with the stream of air. The mixture then escapes through the passages 25 in a series of divergent streams such as C, Fig. 6, the provision of a large number of the passages 25, which collectively have a cross sectional area substantially larger than that of passage 27, serving to prevent the building up of pressure in the chamber 23 to a point sufficient to interfere with the proper operation of the device. The various streams of mingled air and fuel passing out under high velocity` through the openings 25 impinge upon the inclined walls 30 of the casing 29 whereby their direction of movement is changed and at the same time a strong induction action is set up which serves to cause relatively large volumes of air to enter the openings 27. As the fuel has already been very finely divided and intermingled with the air under high pressure and as such mingled air and fuel is discharged from a series of openings 25, it is evident that a very complete mixture of the fuel with the entire mass of air passing through the casing 29 is secured. Thus a very perfect combustion of the fuel is obtained while at the same time but a relatively small quantity of high pressure air is employed. Furthermore by reason of the lthorough mixing of the high pressure air and fuel with a large quantity offree air, little, if any, water is condensed from the compressed air thus eliminating a frequent source of trouble encountered in the operation of many prior devices.

In the device shown in Fig. 7, a'block 4() is illustrated, such block being intended for use in place of the block 5 illustrated in Fig, 1. The block 4() is provided with a converging passage 43 having an extension 44 leading through the nipple 45 and terminating in a discharge nozzle opening. The

left-hand side of the block 40 may be proi l vided with an internally screw Vthreaded flange 46 for engagement with a part such as the member 14 of the support 15 as vpreviously described. The block 40 may also have at its right-hand portion an extension 41 externally screw threaded for attachment to a connection such as the part 1 of Fig. 1 to which may be attached a supply pipe. At its upper portion the block 40 is also provided with a chamber 47 internally screw threaded for the reception of a fuel supply pipe such as 9a. From the chamber 47 a passage 48 leads directly into the side of the passage 44.

With the arrangement just described, air from the supply pipe is caused to flow through the convergent passage or Venturi employ al fuel supply pump or to locate the fuel supply above the apparatus'herein described as the induction action produced would serve to elevate the fuel to a considerable height from any suitable supp-ly tank. When employed as a blower only it is merely necessary to discontinue the feed of fuel through the pipe 9, but in such case, if desired, the pipe 9 with the block 5 may be detached from the support 15 and the air supply connection 1 attached directly to the member 14. As thus arranged the air entering chamber 23 through passage 2() is subjected to a whirling motion as above described which so thoroughly agitates it that any particles of condensed moisture are vaporized and reabsorbed, thus eliminating one of the most serious sources of trouble heretofore experienced in connection with blowers of this type.

While a preferred form of the invention has here been disclosed it is evident that various changes and modifications of the- .with said nozzle, said casing comprising a conical portion into the larger end whereof said nozzle projects for a substantial distance, and a, cylindrical burner portion extending from the smaller end of the conical portion.

2. A device of the class described comprisingmeans having a passage for a stream of gaseous fluid, means for admitting fuel to said stream, means for securing a thorough mixture of such fuel with the fluid, a dis-' charge nozzle having diverging openmgs for such mingled fluid and fuel, and an openended casing comprising a portion of conical form merging into a portion of substantially cylindrical form, such discharge nozzle being constructed and arranged to deliver the mingled fluid and fuel into said casing at a point in the conical portion thereof substantially removed from the largerend of such portion.

3. A carbureting devi-ce having a passage for gaseous fluid, means for admitting liquid fuel to the passage at a point such that the moving stream of fluid serves to induce the inward flow of fuel, a mixing chamber for the reception of fluid and fuel, a nozzle for delivering mingled fluid and fuel from said chamber, and an air inspirator casing of conical form merging into a cylindrical burner portion, said nozzle being constructed n and arranged to deliver into the conical portion of the casing and at a substantial distance from the base thereof.

4. An inspirator device having a funnellike passage pro-vided with air inlet openings at the larger end thereof,'an injector nozzle arranged centrally thereof for inducing the flow of air therethrough, the discharge end of said nozzle being located at a point intermediate the length of said funnel-like passage, a member having therein a mixing chamber and a passage leading therefrom to said injector nozzle, and means for discharging a stream of mingled gaseous fluid and liquid fuel under pressure into said chamber.

5. A fuel burner comprising a casing having a passage therem, a nozzle for the delivering of gaseous fluid under pressure into said passage, means for admitting fuel to said passage for mixture with fluid under pressure, a chamber in said casing forming a continuation of said passage, the wall of said chamber opposite the opening of said passage being inclined to the axis of said passage, a nozzle for delivering mingled fluid and fuel from said chamber, and an air inspirator casing comprising a portion having converging walls and a cylindrical burner portion in continuation thereof, said nozzle projecting for a substantial distance into the conical portion of said casing.

6. A burner comprising a pressure fluid actuated fuel inspirator device, means providing a passage leading from said device and a chamber forming a continuation there` of, baffle means for opposing the direct passage of fluid through the chamber, discharge disposed centrallyA of said openings and projecting inwardly from said base.

7. A fuel burner comprising a member providing a passagefor fluid under pressure said passage having a portion of enlarge diameter, an impact member within said enlarged portion for impingement by the stream of fluid whereby to produce eddies therein, a nozzle for delivering the fluid discharged from said enlarged portion of said passage, and means providing a chamber of conical form having air openings in its base, said nozzle discharging at a point removed from said base and delivering the fluid discharged toward the apex of said chamber.

8. A burner for liquid fluid comprising a. casing having conically converging Walls, means providing for the admission of air into the larger end of the casing, a nozzle for delivering-mingled air and liquid fluid under pressure in divergent streams into said casing, said nozzle projecting into said casing at the larger end thereof, and being so disposed as to deliver said streams divergently toward the apex of the casing, a member extending from said casing and providing a passage leading to said nozzle, and an impact member in said passage upon which the fluid passing therethrough impinges whereby to secure homogeneity thereof.

9. A burner of the class described comprising a casing having a portion of substantially conical form, means providing for the admission of air into the larger end of said casing, a nozzle arranged centrally of said base for discharging gaseous Huid under pressure into said casing, said nozzle projecting for a substantial distance into said casing and being constructed and arranged to direct fluid discharged therefrom in the direction of the apex of said casing, and means interposed between said nozzle and the source of such fluid for insuring agitation thereof.

10. A fuel burner comprising a substantially cylindrical nozzle tube' having a series of divergent discharge openings, a casing enclosing said nozzle tube, meansproviding for the admission of air at spaced points surrounding the base of such tube, said cas ing .having inner Walls which .converge toward a point opposite the end of such nozzle tube whereby fluid discharged from the lat- I under pressure and from which chamber said nozzle openings diverge.

11. An injector device comprising a casing having a funnel-like passage, an open spider for supporting said casing at one end, a. cylindrical injector nozzle arranged cen trally of the casing and projecting for a substantial distance axially of said passage, a member having therein an agitating chamber and a passage leading therefrom to said injector nozzle, and means for discharging a stream of gaseous fluid into said chamber.

12. A fuel burner comprising a cylindrical block having a lateral opening and an axial discharge passage, means for inducing the iow of fuel through said opening and passage, a casing having screwthreaded engagement With said block, said casing having an open spider at its free end, a tubular. structure fixed to said spider, and providing a conical chamber merging into a c lindrical passage having an open end andy a casing secured axially Within sai first casing and having a fuel mixing chamber in continuation of the axial discharge opening in said block.

Signed by me at Boston, Massachusetts, this twentysixth day of February, 1921.

EDMUND HOXIE.

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