US1691690A - Liquid-fuel burner - Google Patents

Description

Nov. 13, 1928. I

' I c. c. WHEELER LIQUID FUEL BURNER Filed May 18, 1926 2 Sheets-Sheet 1 Nov. 13, 1928. 1,691,690 c. c. WHEELER LIQUID FUEL BURNER Filed May 18, 1926 2 Sheets-Sheet 2 INVENTOR Patented Nov. 13, 1928.

COTTRELL 0. WHEELER, OF FOREST HILLS, NEW YORK.

LIQUID-FUEL BURNER.

Application filed May 18,

This in vcntion relates to a liquid fuel burner. The type of the burner to which the invention is more particularly related is that adapted for use in furnaces, boilers, feed water heaters and similar apparatus, irrespective of whether the burner is to be used for the purpose of developing power or furnishing heat or otherwise. In liquid fuel burners of this particular type as heretofore construeted, it has been customary to provide means for pro-heating the fuel and also making provision for the admission of suflicient air to support the combustion of the burning fuel. In all these devices, however,

so fa r as I am aware, the construction is such that the combustion of the fuel is so incomplete that deposits of carbon are made on sub stantially all parts of the burner and surfaces adjacent thereto, whereby in the use of the burner it frequently becomes necessary to clean the same in order to obtain any degree of cfliciency in operation.

In carrying out this invention instead of pie-heating the liquid fuel, I construct a burner in such a manner as to pre-heat the air supplied thereto to the point necessary with the proper proportion of fuel to obtain substantially complete combustion and the burner as will hereinafter be more particularly described is so constructed as to provide a selfcontained combustion chamber within the walls thereof, the fuel being completely burned, thereby preventing the usual carbon deposits and providing a burner of exceedingly high'etficiency.

In the drawing Figure 1 is a partial plan and cross section at different elevations of a liquid fuel burner made in accordance with my present invention, and

Fig. 2 is a central longitudinal section on line 2-2, Fig. 1.

By reference to the drawing it will be seen that in carrying out my invention the burner made in accordance therewith comprises a base 10 which is preferably cylindrical and made of cast metal or other similar suitable material. This base 10 includes an annular bowl 11 having a centrally disposed inlet opening 12. The annular bowl 11 is preferably connected to the cylindrical portion of the base by a bridge or flange 13, spaced appreciably from the upper edges of the cylindrical portion of the base and the annular bowl so as to provide a channel 14 between the same. Within the annular bowl 11 I also employ an inner annular bowl 15. The outer 1926. Serial No. 108,882.

portion of this inner annular bowl is provided with a series of spaced longitudinally disposed ribs or webs 16 adapted to conform to and to fit within the annular bowl 11, and the inner annular bowl is provided with a series of spaced circumferential slots 17 extending through the wall thereof for the admission of air, as hereinafter more particularly described.

In a centrally disposed position relatively to the annular bowl 11 and the opening 12 therein there is a hub 18. This is supported by arms. 19 extending between the same and the annular bowl. Fitted in this hub 18 is a fuel connection 20. The fuel connection 20 extends through the centrally disposed opening in the inner annular bowl 15 and is adapted to supply and distribute the fuel thereto, as hereinbefore described. The inner or under surface of the inner annular bowl is provided with a lagging or lining 21 of fire clay or other similar and equally good heat insulating material and is provided with a cen trally disposed opening 22 through which the fuel connection 20 passes, the same being spaced therefrom so as to form air inlet passages to which reference will be hereinafter made.

The liquid fuel in being supplied to the burner passes through a bore 23 in the fuel connection 20 and through a screen 24 provided therein to the distributor head 25 at the upper or outer end of the fuel connection. The fuel also passes through spaced apertures 26 in a distributor 27 fitted in the distributor head, which latter is so constructed as to overhang the adjacent portion of the inner annular bowl 15, and the outer surface of this distributor head 25 is provided with spaced ribs 28 and resultant intervening channels between each of which one of the apertures 26 in the fuel distributor is caused to lie so that the fuel flowing through each of the apertures 26 is conveyed to the channel between the adjacent ribs 28. The inner surface of the inner annular bowl 15 is also provided with series of radially disposed ribs 29 providing intermediate channels to which the fuel as supplied from the channels in the distributor head is caused to flow therefrom. As will be understood, the fuel for operating the burner is conveyed thereto through a suitable pipe 30 connected to the hub 18, the fuel being conveyed through the pipe 30 from any suitable source of fuel supply.

I have found that it is necessary to make due of course,

tributor head and has entered the interior of the burner.

The burner also includes a plurallty of tubes or pipes forming air ducts. These pipes are arranged circularly and as illustrated each pipe 31 at the lower end thereof enters the channel 14 between the upper or outer ends of the base 10 and the annular bowl 11 and is so placed as to register with one of a corresponding number of openings 32 in the flange or bridge 13 which connects the outer wall of the base with the wall of its annular bowl. It will be understood of course, that these tubes or pipes may be secured to the base in any suitable manner. At their upper ends the tubes or pipes 31 support a hood 33 which forms a duct for the passage of the air in the direction opposite to that in whlch the air passes to the tubes. The peripheral portion of the hood is flanged as indicated at 34 and the inner or lower end of the hood is so constructed as to comprise a centrally disposed discharge nozzle 35. In the flange 34 there is a plurality of openings 36 come sponding in number and preferably in diameter with the openings 32 in the bridge 13. These openings 32 are furthermore similarly placed so that when the hood is in position the upper or outer ends of the tubes or p1 es 31 fit within recesses or sockets 37 provi ed therefor in the flange 34 so that the openings in the flange register with the openings in the tubes. It will also be understood that the tubes may be secured to the flange of the hood in any suitable manner. The main or body portion of the hood 33 is in the form of an inverted cone as is clearly'illus'trated in Fig. 2. The inner surface of the hood 33 is provided with a series of spaced ribs or we s 38 and the wall of the hood is provided with a plurality of spaced circumferentially disposed slots 39 each of which extends through this wall so that a portion of the air passing into and through the hood may flow through these circumferentially disposed slots to the combustion chamber to assist in the combustion of the fuel.

Fitting over the hood and forming a cap for the burner I employ a cover 40. The p'eripheral rtion of this cover rests upon and is suitab y connected to a shoulder 41 provided therefor at the outer edge of'the flange 34 of the hood, and also as illustrated this cover may be fitted in a centrally disposed position with an eye bolt 42 by means of which of course, the cover may be readily placed in position and as readily removed. The tubes or pipes forming the air ducts are placed relatively close to one another so that these together with the hood 33 and the annular bowl 15 form a substantially self-contained combustion chamber indicated at 43.

In the use of the burner as hereinbefore described, the fuel employed is supplied from any suitable source through the pipe 30 and itipassage thereto regulated by a valve or 0t erwise. As the fuel flows to and through the distributor and onto the inner surface of the bowl 15 it is spread and ignited and burns in conjunction with the incoming air which as will be understood passes into the base, through the ducts provided therefor by means. of the pipes or tubes 31, and into the chamber 44 in the cover 40 where it is deflected and its .path of travel reversed so that it then passes downwardly into the hood and through the discharge nozzle 35 thereof immediately above the distributor. The fuel burns while confined momentarily within the bowl and in the combustion chamber within the hood and the ducts formed by the pipes or tubes 31, the flames escaping between the tubes to the chamber within the furnace or heater in which the burner is employed. It will be understood therefore, that the joints between the base and the pipes or tubes 31 and also between the ipes or tubes and the hood and furthermore tween the hood and the cover must be tight so as to prevent the escape of air in order to conduct all the air passing through the burner to the fuel. The fuel in burning in this manner is completely consumed and the resultant temperature raises the temperature of all the surfaces with which the flames come in contact to such an extent that the air is heated to a temperature sufiiciently high to efiectually vaporize the fuel the moment it comes into contact therewith. It will be furthermore noted that the flames in rising on the inner bowl impinge upon its slotted walls and also impinge upon the slotted walls of the hood 33, and that additional or auxiliary air passes through both the slots in the inner annular bowl and the said hood and commingles with the air passing through the nozzle 35 to assist in the combustion of the fuel. It will also be noted that the flames are directed outwardly by the inclined face of the hood 33 and thereby caused to pass to the tubes or pipes 31 and through the spaces between the same.

By experiment I have found that the number of the tubes or pipes 31 employed should be preferably such that no tube forms a duct .for conveying more than 8% of the air admitted to the burner, and that the combined widths of the ducts are appreciably greater than the combined distances between them. As'illustrated, the burner includes 18 ducts so that each duct conveys slightly less than 6% of the air admitted to the burner. I have also found by experiment that it is essential to discharge the air from the ducts in the tubes to the chamber within the cover without first changing the direction of the travel of the air within the tubes, and that the area of the inlet to the hood must be greater than the combined areas of the ducts in the tubes with the cubic capacity of the chamber in the cover and in the hood materially greater than that of the ducts in these inlet tubes so that the velocity of the incoming air is greatly retarded and by expansion in the chamber within the cover and the hood the materially enlarged heatin surface formed by these parts tends to stlll further raise the temperature of the incoming air. Still furthermore, it has been found essential to have the path of the incoming air greater in its downward travel than in its upward travel so as to retard the air as much as possible at the places of contact of highest temperature and also that the discharge outlet for the air should be less than 10% of the area of the airinlet into the hood. I have also found it necessary in sufiiciently heating the air supplied for the purposes intended to make the distance traveled by the air through the ducts less than the travel of the air through the hood and the provision of the conical body portion of the hood together with the fact that the discharge nozzle at the inner end thereof terminates in substantially the same plane as the air inlets to the said ducts makes it possible to meet this condition as the average path traveled by the air in passing in an upward direction through the ducts 31 is appreciably shorter than the average path traveled by the air in passing downwardly through the hood 33.

I claim as my invention:

1. A liquid fuel burner comprising a base, a bowl, means for admitting fuel thereto, a plurality of closely spaced air ducts rising from the outer portion of the said base, a frusto-conical hood extending downwardly between the said air ducts and terminating in a discharge nozzle adjacent the said means for the admission of fuel, and a cover providing a chamber into which the said air ducts discharge, the said bowl, hood, and air ducts constituting a self-contained combustion chamber from which the flame passes through the spaces between the said -air ducts.

2. In a liquid fuel burner, a casing, an annular bowl within the casing, an inner bowl within the annular bowl, the said annular and inner bowls having a centrally disposed opening for the admission of air and the 4 said inner bowl having a plurality of circumferentially disposed slots for the assage of air therethrough, a series of radia ly disposed ribs on the outer surface of the inner I the fuel.

bowl, and a fuel distributor passing through the centrally disposed openings in the said bowls for supplying fuel to the surface of the said inner bowl.

3. In a liquid fuel burner, a casin anannular bowl therein, an inner bowl within the annular bowl, the said bowls bein provided with centrally disposed openings or the passage of air t eret rough and the said inner bowl having aplurality of spaced circumferentially disposed slots for the passage of air therethrough, radially disposed ribs on the outer surface of the said inner bowl extendin between the same and the inner surface 0 the said annular bowl, a plurality of spaced pipes extending from the casing and each forming a duct for the passage ofair, a hood extending inwardly and downwardly from the said pipes, a discharge nozzle at the inner end of the said hood the said hood belng provided with a plurality of spaced clrcumferentially disposed slots for the passage of air therethrough, a series of radially disposed ribs extending from the inner surface of the said hood, a cover extending over sald pi es and hood, and devices for supply liquid uel to the inner surface of the said inner bowl.

4. In a liquid fuel burner a casing, a bowl therein having a centrally disposed opening and a plurality of radially disposed ribs dividing the face of the bowl into a corresponding number of sectors, and a fuel distributor passing through the opening in the bowl and at the discharge end thereof having a plurality of passages corresponding in number with the number of ribs and sector shaped divisions in the surface of the bowl, the said distributor also having at the discharge end thereof a plurality of spaced ribs and intermediate grooves corresponding in number with the ribs and sector shaped divisions in the surface of the bowl with each of the said passages in the distributor opening between the adjacent distributor ribs whereby the fuel discharge from each passage passes to the corresponding grooves between the adjacent distributor ribs and is delivered to the corresponding sector shaped division of the bowl in order to obtain a substantially uniform distribution of the fuel.

5. In a liquid fuel burner, a casing, a bowl therein having a centrally disposed opening and a plurality of radially disposed ribs dividing the face of the bowl into a corresponding number of sectors, and a fuel distributor passing through the opening in the bowl and adapted to supply a quantity of fuel to each of the said sectors of the bowl in order to obtain a substantially uniform distribution of 6. In a liquid fuel burner, a base having an outer wall and an inner wall forming an annular bowl therein, an inner bowl disposed within the said annular bowl and spaced I between the said pi therefrom to provide an air chamber therebetween, means for admitting fuel-t0 .theinner bowl, a plurality of closel spaced air ducts rising from the base, a ood having a frusto-conical portion extending downwardly between the said ducts and terminating in an upwardly and inwardly extending discharge member, and a cover extending over the said air ducts and hood and forming a chamber into which the air from the ducts is dischar ed and its direction deflected in a downwar path into the said hood.

7. In a liquid fuel burner, a casing, a bowl therein having a centrally disposed o ening for the admission of air and a plura ity o circumferentially disposed slots for the passage of air from the outside to the inside of the bowl, and a fuel distributor extending through the said centrally disposed opening for supplying fuel to the surface of the bowl from a centrally disposed osition and above the lowermost of the sai circumferentially disposed slots in the bowl.

8. In a li uid fuel burner, a casing, a bowl therein, a p urality of pipes extendin from the said casing and forming ducts or the passage of air, a hood extending inwardly es and havin a plurality of circumferential y disposed s ots therein for the passage of air from the inside to the outside of the said hood, a plurality of spaced radially disposed ribs on the inner surface of the said hood, a cover extending over the said pipes and hood, and means for su plying fuel to the inner surface of the said W1.

9. In a liquid fuel burner, a casing, a bowl therein, the said bowl having a centrally disposed o ening and a plurality of circumerentia y disposed slots for t e passa of air from the outside to the inside 0 the bowl, a plurality of spaced pipes extending from the said casin and forming ducts for the passage of'air, a ood extending inwardly and downwardly from the said pipes and having a centrally displosed air dischar e nozzle at the inner end t ereof and also havin a pluralit of spaced circumferentially disosed s ots for the assage of air from the inside to the outsi e of the hood, a cover extending over the said pipes and hood, and means for supplying liqui fuel to the inner surface of the bowl.

10. In a liquid fuel annular bowltherein, an inner the annular bowl, the said bowls bein provided with centrally disposed openings or the passage of air therethrough and the said inner wl havin a plurality of s aced circumferentially isposed slots for t e ssage of air from the outside to the insid: thereof, a plurality of spaced pipes extendin from the casing and each forming a duct or the passage of air, and downwardly from the said pipes, a discharge nozzle at the inner end of the said hood, the said hood being provided with'a plurality of spaced circumferentially disposed slots for the passage of air from the inside to the outside thereof, a cover extending over the said pipes and hood, and devices for supplying liquid fuel to the inner surface of the said bowl. Signed by me this 7th day of Ma 1926.

COTTRELL C. WHEE ER burner, a casing, an

a hood extending inwardly bowl wlthin

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