US2249878A - Oil burner - Google Patents

Description

y 1941- c. T. ASBURY 2,249,878

011. BURNER Filed Jan. 21, 1939 *2 Sheets-Sheet l UIJU [HUI July 22, 1941. c. T. ASBURY OIL BURNER Filed Jan. 21, 1939 2 Sheets-Sheet 2 Patented July 22, 1941 UNITED STATES PATENT OFFICE OIL BURNER Charles T. Asbury, Elklns Park, Pa. Application January 21, 1939, Serial No. 252,202

6 Claims.

This invention relates to new and useful improvements in oil burners and more particularly to oil burners of the rotary head wall-flame type.

As is well known, fuel oils for domestic oil burner firing are numerically graded in relation to their volatility, viscosity, flash-point, etc. according to standards determined by the National Bureau of Standards, and current standards for such oils are set forth in a pamphlet entitled "Commercial Standard 0512-38. These fuel oils, beginning with No. 1, which is a relatively volatile high grade oil, are of decreasingly lower grade to No; 6 which is of relatively high viscosity.

It is well known in both the fuel oil and oil burner industries that domestic oil burners of the rotary head wall-flame type as now constructed, for the most part, require the use of a moderately volatile fuel oil such as No. 2 to the exclusion of the use of lower grade low viscosity fuel oils such as No. 3 which, in addition to having a higher B. t. u. rating, usually is less expensive than No. 2 oil.

After many months work on'the problem, I have found that this condition apparently results from the fact that in the rotary head type oil burners now on the market the fuel oil is discharged from the distributor or head in the form of more or less compact jets or streams, while air for mixture with the fuel to insure combustion thereof is discharged by the head from below the point of discharge of the oil.

With the foregoing observations in mind, the present invention consists essentially in the discovery that by causing the relatively compact streams of fuel oil to be distributed over a relatively large area in the form of a thin film prior to being discharged radially from the head, and at the same time causing the air for combustion to be discharged from above the point of discharge of the fuel oil, so that it contacts and mixes with the oil in a region radially remote from the head, I am able to burn lower grade fuel oils of higher B. t. u. rating than has heretofore been possible in burners of the type mentioned.

These results apparently are due to two fac-- tors. In the first place, since the oil is spread out over a relatively large area prior to discharge, in contrast to the relatively dense compact streams heretofore used, instantaneous ignition of lower grade more viscous fuels may be effected and, secondly, by discharging the air from the head abovethe point of discharge of the fuel, the air tends to mix with the fuel at a distance relatively remote from the head, rather than substantially at the point of discharge of the fuel as occurs when the air is discharged at or below the level of fuel discharge, and any tenof oil burner wherein the fuel oil is discharged radially from the head in the form of a relatively thin film or sheet and the air for combustion thereof is discharged by said head from above the point of discharge of the fuel so as to mix with the latter in a region relatively remote from the head.

The invention also consists in certain novel features and details of construction and arrangement hereinafter fully set forth and shown in the accompanying drawings, in which:

Figure 1 is a fragmentary view in section vertically through a rotary head type oil burner embodying the present invention.

Figure 2 is a detached view in perspective partly in section of the head portion of the burner illustrating certain details of the construction thereof.

Figure 3 is a view similar to Figure 1 illustrating a modified form of the invention;

Figure 4 is a top plan view of the modification shown in Figure 3; and

Figure 5 is a fragmentary view in section showing a modified arrangement of heat shield for the fan and baflle construction shown in Figure 1.

Referring now more particular to Figures 1 and 2 of the drawings, reference numeral l designates the main supporting frame of the burner which comprises an annular wall member 2 provided with'lugs 241 for the reception of threaded leg members 3 which extend into supporting cylinders 4 provided with suitable base members 5. Mounted on each threaded member 3 is a lock nut 6 that rests on top of the cylinders 4 so that the frame I can be leveled, raised and lowered to a desired position and locked in place. The annular wall member 2 is further provided with an annular lip I to receive the edges of the plates 8 which support the refractory hearth tile or brick 9.

A motor I0 is suitably secured centrally with respect to the frame I and arranged with its shaft ll extending axially upward through the annular wall member 2 thereof, the lower end of the shaft ll of the motor It being journaled and supported in a ball race or bearing l2.

An oil distributor head designated generally as l3 having relatively large air openings Ila is mounted upon the upper end of the motor shaft "by means of a central boss I, and an oil supply pipe l5 provided with an outwardly re-bent tip it is supported from and extends upwardly adjacent the motor Ill so that said tip it overhangs a channel member ll. The

channel member I1 is provided with an upwardly and outwardly sloping outer wall it and this terminates in a horizontal flange i8 whose outer edge portion 23 is re-bent around a flange 2! at the periphery of the distributor head i3. Extending diagonally upward and outward from the distributor head |3 are one or more radial oil distributor passages 22 and the inner ends of these communicate with the underside of said head l3 at the upper inner edge surface of the channel outer wall II.

A feature of the invention resides in the novel construction and arrangement of a combination fan and battle member designated generally by reference numeral 23 and mounted upon the motor shaft II, above the head, for rotation therewith. The said fan and baille member 23 are suitably spaced above the distributor head l3 by means of a sleeve 24 and said fan and bailie member and the distributor head |3 are secured tightly upon the shaft II for rotation therewith by means of a nut or the like 25. As shown in Figures 1 and 2 of the drawings the fan and baiiie member 23 is of generally inverted dish shape having an imperforate top or cover section 26 and depending peripheral wall portion 21 provided with a series of openings 23 and blades 29 constituting a fan or blower. Ad- .iacent the lower end of said peripheral portion 21 the said wall extends downwardly at an obtuse angle with respect to said portion 21 as indicated at 3| to form a lower imperforate bailie or ring portion spaced outwardly adjacent the outlet ends of the oil distributor passages 22. It is also contemplated to provide the member 23 with a heat shield 32 arranged outwardly ad- Jacent the baille 3| for the p p se of maintaining the latter relatively cool and thereby minimizing the formation of carbon on said bailie.

Thus the fan which provides air for combustion of the oil fuel is disposed above the points.

of oil discharge and in operation of the device, as the head I! and channel member I! rotate together with the fan and baffle member 23, the oil, fed to said channel member II by the pipe l5, works its way upwardly along the wall I! thereof and into the passages 22 through and by means of which said oil is flung radially against the inner surface of said bailie portion 3| of the member 23. As the oil impinges against the baflle 3| the obstruction afforded by the latter causes said oil to spread or thin out over a relatively large area in the form of a film which flows downwardly along the inner wall of said bailie 3| to the lower edge thereof from which it is flung radially outward to a point adjacent the wall of the furnace.

As the oil fuel is thus thinned out and disblades 29 in the upper portion 21 of the member 23 function as a fan or blower to draw air upwardly through the opening in the hearth provided by the annular frame 2 and thence upwardly between the channel l1 and shaft H and openings |3a in the head I 3 as well as upwardly through the space between said head l3 and baflie 3| after which it is discharged outwardly through the openings 23 and radially from the member 23 for mixture with the underfed fuel at a point radially remote from the burner structure.

The variousdetails of construction of the fan and battle member just described may of course be varied so long as the previously mentioned essential features are retained, and a modified form thereof which gives satisfactory results is v charged from the lower end of the baflie, the I shown in Figures 3 and 4 of thedrawings. In

- this form the i'an and baflle member is designated 83 and generally speaking is of annular or ring form having an inner wall portion 34 providing a baflie spaced outwardly adjacent the oil discharge passages 22 and an outer wall portion 35 providing a heat shield intermediate the baffle 34 and which functions in a manner similar to the shield 32 to maintain said baflle 3d substantially cool thus minimizing carbon forming on the battle.

The baffle ring is mounted upon the motor shaft II .by means of a spider structure 33 located within the annular baiiie and provided with a central boss 31 for reception of said shaft, a nut 38 being employed to secure the said fan and baflle member 33 on the shaft H for rotation therewith. A unique feature of this particular form of the device is the fact that the spokes or elements of the baiiie supporting spider structure 3B are of radially increasing width and provided with a definite curvature declining in the direction of their leading edge to constitute fan blades. The blades thus provided by the spokes of the spider 36 function, after the manner of the blades 29 previously described, to draw air upwardly through the hearth opening and thence upwardly between the channel I1 and shaft II and openings |3a in the head l3 as well asupwardly through the space between the latter and the baiiie 34 after which it discharges and mushrooms outwardly and downwardly for mixture with the underfed fuel at a point radially remote from the burner structure, the oil being discharged from the lower edge of said baiiie 34 in the form of a thin film after discharge from the passages 22 against the inner surface of the baflle in the manner previously described.

A modified form of heat shield for the fan and baiile member 23 shown in Figures 1 and 2 is shown in Figure 5 of the drawings. In this arrangement the heat shield 32a forms an integral part of the member 23 and is formed by upwardly turning the lower edge of the portion 3| constituting the baffle. This particular arrangement of the heat shield provides an upwardly opening channel 39 which, during rotation of the burner head, catches a portion of the air discharged by the blades 29 of the fan which aids in maintaining the baiiie portion 3| relatively cool.

In the two forms of rotary head burners illustrated and described herein it will be observed that substantially all of the air drawn through the hearth opening defined by the annular wall member 2 is caused to be discharged from a point above that of the fuel discharge, thus preventing mixture of the air and fuel at a point adjacent the periphery of the head as is the case when the air is discharged at or below the level'or point of fuel discharge, and insuring such fuel and air mixture taking place in a region radially remote from said head. This arrangement together with that of impinging the streams of oil against a baflie to disperse them over a large area in the form of a film prior to discharge for combustion enables the efficient burning of lower grade fuel oils of higher B. t. u. rating than heretofore possible thus affording a greater heat output per unit quantity of fuel at generally decreased cost.

While certain particular embodiments of the invention have been illustrated and described herein, it is not intended that the invention be precisely limited thereto but that changes and modifications may be incorporated and embodied therein within the scope of the annexed claims.

In this connection, it is pointed out that successful operation of the device is not confined to battle structures which rotate with the fuel distributor head but that equally successful results are obtained with the use of a stationary bafile and the limitation of the disclosure herein to devices embodying rotating baflles is solely because such arrangements are deemed the more practical from the standpoint of simplicity and cost of manufacture.

I claim:

1. In a burner structure of the type described, the combination with a head rotatable about a vertical axis and having means for laterally discharging streams of liquid fuel, of a structure mounted above said head and rotatable therewith comprising a depending baille disposed in the path of said streams of liquid fuel and against which said streams impinge and disperse in the form of a thin film prior to discharge radially outward therefrom, means disposed at a level above said rotatable fuel stream discharging head for entraining air and discharging the same from above the fuel discharge for admixture with said fuel in a region radially remote from the rotatable head to form a combustible mixture, and means disposed outwardly adjacent said bafile constituting a shield for the baffle against the heat of combustion of said mixture.

2. In a burner structure of the type described, a head rotatable about a vertical axis constructed and arranged for laterally discharging streams of liquid fuel comprising an annular fuel receiving channel member and a head element superimposed thereon provided with at least one laterally directed fuel discharge passage and an upwardly directed air opening, and a structure mounted above said head and rotatable therewith comprising a depending bafile disposed laterally adjacent the outlet end of said fuel discharge passage and against which fuel discharged from said passage impinges and is dispersed in the form of a thin film prior to discharge radially therefrom, and means disposed at a level above said bafile and fuel discharge head for entraining air upwardly through the discharge head and its air opening and between said fuel discharge head and the baffle and discharging the same from above the fuel discharge region for admixture with said fuel in a region radially remote from the head to form a combustible mixture.

3. In a burner structure of the type described, a head rotatable about a vertical axis constructed and arranged for laterally discharging streams of liquid fuel comprising an annular fuel receivin channel member and a head element superimposed thereon provided with laterally directed fuel discharge passages and upwardly directed air openings, and a structure mounted above said head and rotatable therewith comprising a depending baffle disposed laterally adjacent the outlet ends of said fuel discharge passages and against which the streams of fuel discharged from said passages impinge and disperse in the form of a thin film prior to discharge radially therefrom, means disposed at a level above said baffle and fuel discharge head for entraining air upwardly through the discharge head and its air openings and between said fuel discharge head and the bafiie and discharging the same from above the fuel discharge region for admixture with said fuel in a region radially remote from the head to form a combustiblemixture, and means disposed outwardly adjacent said bailie constituting a shield for the battle against the heat of combustion of said mixture.

4. In a burner structure of the type described, a head rotatable about a vertical axis constructed and arranged for laterally discharging streams of liquid fuel comprising an annular fuel receiving channel member and a head element superimposed thereon provided with laterally directed fuel discharge passages and a plurality of upwardly directed air openings; a baffle disposed laterally adjacent the outlet ends of said fuel discharge passages and against which the streams of fuel discharged from said passages impinge and disperse in the form of a thin film prior to discharge radially there from, and draft inducing means disposed at a level above said fuel discharge head and rotatable therewith for entraining air upwardly through the discharge head and its air openings and between said fuel discharge head and the baflle and discharging the same from above the fuel discharge region for admixture with said fuel in a region radially remote from the head to form a combustible mixture.

5. In a burner structure of the type described, a head rotatable about a vertical axis constructed and arranged for laterally discharging streams of liquid fuel comprising an annular fuel receiving channel member and a head element superimposed thereon provided with laterally directed fuel discharge passages and a plurality of upwardly directed air openings, a baiile disposed laterally adjacent the outlet ends of said fuel discharge passages and against which the streams of fuel discharged from said passages impinge and disperse in the form of a thin film prior to discharge radially therefrom, means disposed at a level above said fuel discharge head and rotatable therewith for entralning air upwardly through the discharge head and its air openings and between said fuel discharge head and the baffle and discharging the same from above the fuel discharge region for admixture with said fuel in a region radially remote from the head to form a combustible mixture, and means disposed outwardly adjacent said baiile constituting a shield for the baffle against the heat of combustion of said mixture.

6. In a liquid fuel burner structure of the type described, a head rotatable about a vertical axis and having at least one opening therein for laterally discharging a stream of liquid fuel, depending bafile means rotatable with said head and disposed in the path of discharge of the fuel stream for engagement by said stream and operable to disperse the same into a relatively thin film and then discharge the same radially outward from the lower edge of said baffle means, and means also rotatable with said head for discharging air laterally outward from the burner structure for admixture with said discharged fuel, the point of air discharge from the burner structure being at a level above the point of fuel discharge from the baffle and the spacing of said level of air discharge above said point of fuel discharge being such that mixture and combustion of said discharged air and fuel takes place only in a region radially remote from the point of fuel discharge from said baflie means.

' CHARLES T. ASBURY.

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