US2194136A - Burner for liquid fuel - Google Patents

Description

March i9, 1940. J. l.. BREESE BURNER FOR LIQUID FUEL Original Filed Sept. 1l, 1957 ooeeeeeooooW-/ W/ Ow@ y Maw Patented Mar. 19, 1940 UNIT-EVD STATES BURNER FOB LIQUID FUEL James L. Breese, ,Santa Fe, N. Mex., assignor, by mesne assignments, to Motor Wheel Corporation, Lansing, Mich., a corporation of Michigan .Original applicationA September 11, lliiii'i,y Serial Divided and 'this application a March 14, 1938, Serial No. 195,127

a claims.

My invention relates to an improvementin `'burners for liquid fuelsP such as hydrocarbons,

` and has for one purpose the provision of a burner which can be turned down to a very small ilre, or low draft, without destroying the characteristc mode of combustion described, for example, in my prior issued Patent No.' 1,102,929, issued February. 19, 1929.V

Another purpose is theprovision of 4means for permitting low draft burning with such a burner while preventing `down drafts'from upper portions of the combustion chamber which would disadvantageously affect combustion..

Another purpose is the provision of such means l which are adaptable for ready removal topermit easy cleaning of the burner and for adjustment of the burner capacity.

Another purpose is the provision, in connection with one of my burners, of a lower supplementary burner which may have the function of a pilot light for maintaining combustion during periods when a minimum heat or no heat is desired. Other purposes will appear from time to time inthe coursevof the specification and claims.

The present application is a division of my application Serial No. 163,369, tiled September 11, 1937. o

I illustrate my invention more or less diagrammatically in the accompanying drawing, wherein:

Figure 1 is a vertical section; Figure-2 is a vertical section on -an enlarged scale of a portion of the device showing a variant form or baille with the baille in side elevation:

Figure 3 is asection-similar to Figure 2 show shell. 3, is a horizontalpartition secured to thev inner shell and provided with a central aperture l. li is a preferably removable baie with a central aperture v6.. 1 is a 'combustion chamber member, herein shown" as generally cylindrical,

with a bottom 8 which may be` formed, if desired,

in one piece and which may be secured in any suitable way as by bolts or welding 9 to'the memv ber A3. Y l

lo 1s any mutable fueisupply pipe 'exten/amg to the bottom The means for supplying the fuel 'is .not herein shown since it does not of itself form part of the present invention, but it will be understood that any suitable oat chamber or the iikemaygbeemployed for governing the desired flow of fulffor example a liquid hydro-V carbon fuel, to the bottom 8.

I I is a closure member securedwithin the shell 2 land provided with apertures I2 which may be in a separate ,removable plate I3 closing the centralaperture Il ofthe member II. I herein illustrateair'inlet apertures I5 in the bottom of the shell 2 and it will be understood that anyv member 1 is provided with an upper-'row of sec- .Qndary air inlet-apertures I8, herein-shown as upwardly and inwardly inclined. A plurality of ranged in rows in alower portion of' the member 1. The bottom row of apertures I8 is also indicated. f' I Referring to Figure 1, I illustrate a removable baille ring I9 in theform of a spiral having an arc of about 360 degrees. It will -be realized that this 4element-may be formed with a 'greater or a lesser arc, but 360 degrees is a Aconvenient length. The lower end is shown as at 2li resting upon the bottom of the chamber 1. It l be noted thatl the spiralbaiiie I9 includes an pper portion 20a which extends above the levelof the lowest row of holes I8. Any suitable additlonalrmeans may, if desired, be employed in order to permit the position or support of the baille I9. I illustrate,

preferably smaller apertures I1 are shwn ar- 1 for example, an inwardly extending lug 2I 'for` supporting an intermediate portion of the baille vand additional lugs may, if desired, be employed.

However, if the baille is formed to conform substantially in its exterior periphery to the inner l face of the wall of the member 1, no additional means are necessary.

Under some circumstances, however, I prefer to have a perceptible air space betweenA the outer edge of the baille and fthe inner face. of the member 1, and in such 'event the supporting members 2l may be desirable.

Referring to Figure 2, I illustrate a baille IaA top and bottom of the chamber 1. and extending entirely above the bottom apertures Il. A plurality of the supporting members 2I may be employed in order to position the baille or any other suitablel supporting means maybe employed. It will be understood that whereas in the drawing the baille is shown as engaging theinner face of vthe wall 1it may be spaced outwardly therefrom if desired, -and under some circumstances I prefer to have the circulation of air upwardly about the outer edge of the baille and along the inner face of the wall 1 Referring to Figure 3, I illustrate a spiral baille Ish which extends substantially .from top to bottom of the chamber but which is shown as ter-'- niina'ting short of the secondary air apertures similar to the haine I 9, but located between-the' I6. In general, no supportingl means are necessary as the lower end ofthe bame simply rests on the bottom. If desired, I may position a plurality of members 2l to support the baille.

Referring to Figure 4, I illustrate in addition to the bottom baille I9 a similar spiral baille Nc located above the baille I9 and preferably extending adjacent the upper portion of the chamber 1. I illustrate it, however, as terminating short of the secondary air aperture i6. It may be mounted for example on'a plurality of inwardly extending members 2|. i

'It vwill be realized that whereas I have described and shownya practical and operative device, nevertheless many changes in size, shape, number and disposition of parte may be made without departing from the spirit' of my invention. -I therefore wish my drawing to be taken as in a broad sense illustrative and diagrammatic rather than as limiting me to the specific details as shown herein.

The use and operation of my invention. are as follows:

In the normal operation of the device the characteristic combustion method of my Patent Number 1,702,929 may be carried on. The primary air supply enters through the apertures Il and mingles with the hydrocarbon vaporized by the combustion. The heat of combustion, once the device is in operation, vaporizes the hydrocarbon and the vaporized hydrocarbon rises and mixes with the primary air supply to form a primary mixture. This primary mixture moves upwardly toward and through the aperture 8 of the baille 5 and there receives the secondary air supply which is admitted through the apertures I6. 'Ihis produces a ilnal mixture which burns and provides the heat for 'the stove or furnace unit.

Preferably, whether by natural draft or by any suitable fan or the like, not herein show n,

sufficient air is admitted ior maintaining combustion at a rate sumcient to give the desired heat. Any suitable control means, thermostatlc or otherwise, may be employed for' controlling the desired heat produced.

In the event that it is desired to turn down the unit to av minimum heat', or to practically no heat, the air supply is reduced and combustion is correspondingly reduced. In the structure as shown inmy Patent Number 1,702,929, there is a limit below which the stove does not operate emciently. For example, unless a sumcient air supply and sumcient rate ol' combustion is maintained, the secondary air or the air above the baille 5 tends to eddy back andclrculate down into the primary combustion aune, with the resuit that the balance betweenthe primary and secondary zones is destroyed and mymethod of combustion is interrupted, resulting in.' carbon deposit and ineiilcicnt combustion. j l

I ilnd that the interposition of a baille. such as the one' shown herein alt IQ, prevents this down draft and my primary mixing andcombustion may be carried on by means of the holes 18, and the secondary air may then be supplied by some or all of the holes l1. In other words, the primary zone moves down to or is limited to the holes below the baille, and the holes above the baille which previously operated as a source of primary air then become the source of secondary arcaico In practice, and depending upon the Vsize and shape of the burner, the fuelused and draft conditions, there is some diuiculty in positioning the baille at the right point for a maximum turndown and in controlling combustion conditions adequately to permit a 'maximum turndown, while permitting initiation of combustion with vthe baille in place. I nd that a spiral baille,

such as I have shown herein at I9 and i9b, the maximum turndown may be obtained by having a spiral baille extend to or be located in the bottom of the chamber 1. However, the fact that a spiral is used and not a closed or solid baille member or ring, is advantageous in that when 'combustion is initiated as by dropping a piece of the chamber 1, as the rate of ow of fuel is increased by the turning of any suitable valve' means controlling the fuel inlet, the combustion rises higher and higher in the chamber until nally full combustion is taking place. In the earlier stage of the combustion, when only a small supply of fuel is admitted, the bottom row of apertures, or that part of them which are oelow the baille, supply the primary air and the rows of apertures above the lowest part of the baille supply the secondary air. As the flow of -fuel is increased, the next higher apertures are converted into primary apertures and the zone of division between primary and secondary air rises along the baille. Under some circumstances it may be advantageous to carry the Abaille all the way up to the top of the pot, though I nd that the form of- Figure 1 is highly practical. Figure 2 is a form which permits only of a somewhat higher turndown, but which is highly practical where a low turndown is not necessary.

I claim:

l. Combustion apparatus comprising a hydrocarbon burner of the vaporizing pot type, said burner including a mixing chamber having a plurality of air inlet apertures in the wall thereof located in a plurality of vertically spaced horisontal rows, means for admitting a liquid hydro carbon to the mixing chamber, and a spiral bale having an arcuate length of at least 360 degrees located intermediate the top and bottom of said mixing chamber, said baille having a central aperture therethrough providing communication between `the upper and lower portions of the mixing chamberand intersecting the plane of at least one row of air inlet openings. Y

2. Combustion apparatus as defined in claim 1, wherein the radially outer edge of said'splral baille conforms generally -to and closely approaches the inner iace ofthe mixing chamber wall.

3. Combustion apparatus as donned in claim l, wherein the-baille .intersects the plane-oi' 'at least two rows of `air inlet openings.

JAMES L. BREESE.

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