US2112888A - Burner - Google Patents

Description

2 Sheets-.Sheet l BURNER J. E. GREENAWALT Filed Feb. 9,

April 5, 193s.

April 5, 1938.

" J. E. GREENAWALT BURNER Filed Feb. 9, 1934 2 Sheets-Sheet 2 HTroe/VEK Patented Apr. 5, 1938 UNITED STATES- PATENT oFFlcE I BURNER John E. Greenawalt, New York, N. Y.A n Application February 9, 1934, Serial No. 710,397

claims.

' My invention has relation to improvements in burners particularly adapted for the burning of liquid fuel, such as oil, -and it consists in the novel features of construction more fully set forth in 5 the specication and pointed out in the claims.

The present invention is an improving departure from my co-pending application Serial No. 685,820, filed August 19, 1933, and as in said application the essential features of the invention are directed to the means for carbureting and distributing the fuel over a wide area so' that combustion may be complete and productive of intense heat.

Among the objects of the invention are the l5 following: the provision of a burner embodying a fuel distributing head for subdividing the fuel intoA minute particles and mixing air with said minute fuel particles before they are discharged from the distributing head to obtain not only a thorough atomization but also partial vaporization of the fuel; the provision of a secondary supply of air on both sides of the surfaces from which the mixed air and fuel discharge to insure ample air to support the combustion of the fuel; the forceful ejecting of the mixed air and fuel from the oriiices of the distributing head to prevent combustion within the head; the protection of the burner against the heat of the combustion chamber by the provision of a suitable shield held in spaced relation with said head, and the provision of means for circulating air through such space to keep down the temperature of the shield, thus protecting the distributing head and pro- 4longing'the life of the shield; the arrangement of the fuel discharge ports to expedite reception of the fuel and eil'ect a radial discharge thereof to expel the mixed fuel and air from the distributing head before ignition thereof; and such other objects and advantages as are inherent in the invention and which will become more apparent from a detailed description of the invention in @connection with the accompanying drawings, in iff'whichi l Y Figure 1 is a side elevation of my improved @i5 burner mounted for operation in connection with a down draft furnace, a part of which is shown in longitudinal section; Fig. 2 is a middle vertical longitudinal section through the burner and that partv of the furnace immediately adjacent the 7,

burner; Fi'g. '3 is a plan view of a portion of the furnace showing the annular air-,control damper for regulating the air supply to the furnace; Fig. 4 is a horizontal cross-section taken on a plane indicated by the line 4-4 of Fig. 2; Fig. 5 is a horizontal cross-section taken through the fuel` distributing head on a plane indicated by the line f 5 5 of Fig. 2; Fig. 6is a bottom plan of a fragment of the distributing head disk 2; and Fig. 7 is a cross-sectional detail taken through the furnace damper on the line 'If-'I of Fig. 3.

Referring to the drawings, B represents my improved burner positioned in the opening O in the roof R of the down draft furnace F, the fuel distributing head I of the burner projecting into combustion chamber C. The burner B is carried by a suitable housing H which is supported by anges f, f on what may be termed a wall box W positioned in the opening O and resting on the furnace roof R. The fuel distributing head I comprises a circular disk 2, at the center of which .is a perforated boss 3 in -which is securely fixed a tube 4 which extends upwardly therefrom and is rotatably mounted within a bearing member 5 supported from the top 6 of the housing H. The bearing member comprises an upper cylindrical section 1 and a lower section 1', and in the upper section are ball bearings 8 and 8 in spaced relation which take both the vertical and lateral thrust of the tube 4 when the latter is rotated, as presently to appear. A fuel receiving chamber 9 is formed around the boss 3 of disk 2 by an annular member IIJ having a flanged portion II and a central frusta-conical portion I2 which encircles the boss 3 and the lower part of tube 4. 'I'he boss 3 is shouldered at the upper part of its inner surface so as to provide an oil well I3 around the tube 4, into which the fuel oil is discharged from a feed pipe I4 within the housing H and connected with a pipe I5 passing out of the housing to a suitable source of fuel supply (not shown). A series of bosses I6 extend entirely around and inwardly from the periphery of the disk 2 on the upper surface thereof, and a series' of bosses II extend entirely around and inwardly from the periphery of the lower surface of the disk 2, and the iiange II of the member Ill is securely bolted against the bosses I6 while a circular plate or shield I8 (slightly conoidal) is bolted against the bosses Il. A single s et of bolts I9, uniformly spaced, secure all three of these distributing head members in intimately assembled relation. The bosses I6 are shaped to provide angular passages or ports 2li between them. The inner parts a of the ports communicating with the chamber 9 approach tangency to the vWall I2 of the chamber 9, and the outer parts b of the ports are radially disposed with respect to the periphery of the distributing head I. The bosses Il which serve to hold the plate I8 in spaced relation with disk 2 are4 shaped similarly to the bosses I6, and, of course, the passage-ways 2I between said bosses would be shaped similar to the passage-ways or ports 20. The reason for shaping the passage-ways will presently appear.

On the upper surface 22 of flange II are a plurality of radially disposed ribs or vanes 23 which serve as fan blades for drawing air to the periphery of the distributing head I when the burner is in operation. An air-gate or damper 24 is provided in the wall of housing H and is equipped with a notched rack 25 pivotally mounted on a pin 26 near the lower end of the gate 24 so that it may engage a lip 21 projecting from flange j to hold the gate in any one of a series of open positions for controlling the amount of air admitted into the housing H. As explained above, the fuel distributing head is rotatably supported by the bearing member and is adapted to be rapidly rotated by means of a motor M to s shaft 28 of which tube 4 'is directly connected by means of a coupling comprising members 29 and 30 secured together in spaced relation by means of bolts 3| and threaded sleeves 32. The provision of the space 33 between the coupling members 29 and 30 permits air to enter the upper end of tube 4 through which it passes to the inner surface of plate I8 taking up much of the heat from said plate before discharging from the passage-ways 2| between bosses I1. Ihis circulation of air over the inner surface of plate I8 thus servesto hold down the temperature of said plate so that it will not be destroyed by the heat of the combustion chamber.

In order that there may be an adequate supply of air within the combustion chamber C to maintain combustion of the fuel throughout said chamber a plurality of a'ir intake openings 34 are provided in the roof R of the furnace F, said openings coinciding with openings 34 in the top plate 35 of the wall box W. An annular damper plate 36 is mounted on the plate 35 above the openings 34', said plate 36 being confined by means of a series of evenly spaced rollers 31 mounted on studs 38. The plate 36 is provided with a plurality of openings 39 of the same size and spacing as the openings 34 so as either to close the openings 34 or entirely open them by the proper rotation of the plate 36 by means of a handle 46 provided for this purpose. 'Ihe amount of movement of the plate 36 is limited by a pin 4I projecting from the plate 35jinto i a slot 42 at the margin of the plate 36.

It will be observed that the bosses I6 are widened slightly toward the periphery of disk 2, and the passage-ways b are correspondingly reduced in size toward the periphery. 'I'he purpose of this is to limit the width of the oil passages toward the periphery of the disk and thereby obtain a maximum -centrifugal action on the stream and discharge it with sufficient velocity to throw the fuel particles away from the disk and thus prevent ignition of the fuel in the passage-ways. The purpose of having the inner` part a of the passage-ways somewhat' tangential to the wall I2 of the chamber. 9 is to give greater freedom of entry of the oil particles to the passage-ways as the disk is rapidly revolved in the direction of the arrow (Fig. 5). However, the passage-ways must not be tangential at their outlets because it lis one 'of the objects of the invention to expel the mixed fuel and air from the distributing head as far as possible and a tangertial outlet would cause the fuel mixture to hug the periphery of the distributing head. It is for this reason that the outer parts b of the passageways are radially disposed with respect to' the distributing head. 'Ihis arrangement also prevents the formation of eddy currents within the distributing head YI whereby the flames outside of the head might be drawn into thel head and cause premature combustion.

The action of my improved oil burner is as follows. 'I'he oil is delivered from the pipe I4 into the oil well I3 around the tube .4 from which it is expelledby centrifugal action after which it impinges on the inner conical surfaceof the wall I2 of the receiving chamber 9. The centrifugal action causes the oil to spread out over this surface into a very thin film which becomes more atomized as the oil approaches the inside of iiange II where it enters the passage-ways 20 between bosses I6. Of course, air is mixed with the oil as it discharges from the oil well I3 and when the oil reaches the passage-ways 20 it is further broken up and mixed with air by the fan action of the bosses I6. Obviously, the passage-ways 20 all receive approximately the same amount of oil and air on account of the uniform distribution thereof by the centrifugal force; and on account of the radial disposition of the outer portions b of the passage-ways 20 and the con-.- stricted outlets of the passages which serveas nozzles, this fuel 'mixture is ejected under considerable force from said passage-ways by the time the oil passes through the passages 20 and is about to be discharged therefrom. It is not only uniformly distributed around the fuel distributing head I, but is also in a very fine state of division, or atomization, so that it may be very easily and quickly vaporized the instant it enters the combustion chamber C. In addition to the air that is discharged from the passages 20 with the oil there are two other supplies of air to insure thorough atomization and combustion at the distributing head. The one supplyv of air is created by the fan blades 23 projecting upwardly from the flange II and enters the combustion chamber C in sheet form immediately above the fuel mixture. The other air supply is discharged from the passage-ways 2l between disk 2 and plate I8 and enters the combustion chamber C as a plurality of jets immediately below the fuel mixture issuing from the passage-ways 20. The bosses I'I serve as fan blades to maintain a high velocity circulation of the air through passageways 2i. Thus the fuel mixture enters the combustion chamber C between two air supplies so as to insure suillcient air to completely atomize the fuel and obtain`an effective ignition. Of course, combustion is continued in the combustion chamber and additional air that might be needed to further the combustion in said chamber'may be obtained by regulating the damper plate 36. Thus there are three air 'supplies for the fuel, the primary air supply entering the combustion chamber C intimately mixed with the fuel from the distributing head I, andthe secondary air supply entering the combustion chamber on both sides of the spray of mixed fuel and air issuing y from the distributing head I.

I have found in. practice that the amount of primary air should withwhich the secondary air passes into the combustion chamber C is increased by the vanes 23 on the flange II. The supply of air'entering the combustion chamber below the fuel mixture also serves the purpose of keeping down the temperature of the plate I8 which serves as a protecting shield for the burner to prevent the destruction of the same from the intense heat of the combustion chamber C.

The high peripheral speed of the distributing head i causes an intense turbulence in the combustion chamber C. This turbulence expedites the mixing of the atomized fuel and the air so that I obtain an explosive mixture almost as soon as the fuel and the air enters the combustion chamber C. Therefore, combustion proceeds immediately and continuously as the mixed gases are whirled downwardly through the combustion chamber.

Having described Amy invention, I claim:

1. In a burner for liquid fuel, a fuel distributing head, means for feeding fuel into the head, fan blades within the head for forcing air therethrough, an impeller associated with the head, means for rotating the distributing head, a disk supported in spaced relation with said distributing head to protect the same from the heat of the burning fuel, and means for circulating air in the space between said disk and the head.

2. In a burner for liquid fuel, a fuel distributorand impeller in the general shape of a disk having a central chamber, said impeller having an air inlet, a plurality of radially disposed blades circumferentially spaced around said central chamber, some of said blades forming fuel passages between them and other of said blades forming air passageways between them, a plurality of fan blades on one side of the impeller, a disk on the other side of the impeller to shield the same from the heat of the burning fuel, and means for introducing fuel to said chamber.

3. In a burner for liquid fuel, a fuel distributor and impeller in the general shape of a disk having a central chamber, a plurality of radially disposed blades circumferentially spaced around said central chamber, said chamber having an inlet for air, means for introducing fuel into said chamber, said blades forming fuel and air passages between them, a plurality of fan blades on one side of the impeller, a disk on the other side of the impeller and spaced therefrom to shield the impeller from the heat of the burning fuel, and a plurality of radially disposed blades circumferentially spaced between the impeller and said shield disk, said blades extending inwardly from the periphery of the impeller.

4. In a burner for 4liquid fuel, a fuel distributing head, said head comprising a hollow disk-like member having an annular chamber and a hollow marginal flange communicating therewith, an annular fuel reservoir within said chamber, means for feeding fuel to said reservoir, the outer wall of said chamber being inclined outwardly and downwardly, and means for rotating said head and the fuel reservoir, to expel the fuel therefrom by centrifugal action.

5. In a burner for liquid fuel, a fuel distributing head, said head comprising a hollow disk-like member having an annular chamber and a hollow marginal ange communicating therewith, an annular fuel reservoir within said chamber, mean for feeding fuel to said reservoir, the outer wall of said reservoir inclining outwardly and upwardly, and the outer wall of said chamber being inclined outwardly and downwardly, and means for rotating said head and the fuel reservoir, to expel the fuel therefrom by centrifugal action.

JOHN E. GREENAWALT.

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