US2182466A - Burner for liquid fuel - Google Patents

Description

Dec. 5, 1939. BREESE 2,182,466

BURNER FOR LIQUID FUEL Original Filed Feb. 8, 1937 [722 672607" 175477265 L .fireepe Patented Dec. 5, 1939 UNITED STATES BURNER FOR LIQUID FUEL James L. Breese, Santa Fe, N. Mex., assignor to Oil Devices, Santa Fe, N. Mex., a

nership of Illinois limited part- Original application February 8, 1937, Serial No.

124,695. Divided and this application September 11, 1937, Serial No. 163,369

3 Claims.'

My invention' relates to an improvement in burners for liquid fuels, such as hydrocarbons, and has for one purpose the provision of a burner which can be turned down to a very small fire,

or low draft, without destroying the characteristic mode of combustion described, for example, in my prior issued Patent No. 1,702,929, issued February 19, 1929.

Another purpose is the provision of means 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 which are adaptable for ready removal to permit 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 in the course of the specification and claims.

The present application is a division of my application Serial No. 124,695, filed February 8, 1937.

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

Figure 1 is a vertical section;

Figure 2 is a plan view of a, portion of the device; and

Figure 3 is an enlarged view of a portion of the structure shown in Figure 1, taken in vertical section.

Like parts are indicated by like symbols throughout the specification and drawing.

Referring to the drawing, I generally indicatesan outer furnace or heater shell and 2 an inner shell. 3 is a horizontal partition secured to the inner shell and provided with a central aperture 4. 5 is a preferably removable baflie with a central aperture 6. I 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 member 3.

I0 is any suitable fuel supply pipe extending to the bottom 8. 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 float chamber or the like may be employed for governing the desired flow of fuel, for example a liquid hydrocarbon fuel, to the bottom 8.

H is a closure member secured within the shell 2 and provided with apertures l2, which may be tral aperture H of the member II. I herein illustrateair inlet apertures IS in the bottom of the shell 2 and it will be understood that any suitable means, whether by natural draft or by forced draft, may be used to supply air to the space between the shells l and 2,.which air is caused to flow through the apertures I5, upwardly through the apertures l2, and into the space between the members 'I and the shell 2. The member 7 is provided with an upper row of secondary air inlet apertures 16, herein shown as upwardly and inwardly inclined. A plurality of preferably smaller apertures I'I are shown arranged in rows in a lower portion of the member I. The bottom row of apertures 18 is also indicated.

Positioned above the bottom row I8 is a removable baflie ring l9, herein shown as provided with a plurality of legs or supports 20, whereby the baiile ring I9 is removably supported on the bottom 8. Other supporting means may be employed but I find the employment of legs 20 a practical solution of the problem. The ring 19 has a central aperture 2| corresponding to the aperture 6 in the bailie plate 5. It will be observed that the ring is shown as provided with an upwardly turned central flange l9a about the central aperture 2|.

In the normal operation of the device the characteristic combustion method of my Patent Number 1,702,929 may be carried on. The primary airsupply enters through the apertures l1 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 6 of the baflie 5 and there receives the secondary air supply which is admitted through the apertures l6. This produces a. final 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 shown, sufficient air is admitted for maintaining'combustion at a rate suflicient to give the desired heat. Any suitable control means, thermostatic or otherwise, may be employed for controlling the desired heat produced.

In the event that it is desired to turn down the unit to a minimum heat, or to practically no heat, the air supply is reduced and combustion is correspondingly reduced. In the structure as shown in my Patent Number 1,702,929, there is a limit below which the stove does not operate efficiently. For example, unless a suflicient air supply and sufficient rate of combustion is main tained, the secondary air or the air above the bailie 5 tends to eddy back and circulate down into the primary combustion zone, with the result that the balance between the primary and secondary zones is destroyed and my method of combustion is interrupted, resulting in carbon deposit and ineflicient combustion.

I find that the interposition of a baflle, such as the one shown herein at l9, prevents this down draft-and my primary mixing and combustion may be carried on by means of the holes l8, and the secondary air may then be supplied by some or all of the holes H. In other words, the primary zone moves down to or is limited to the holes below the baflie, and the holes above the baflle which previously operated as a source of primary air then become the source of secondary air.

Referring to the flange Illa: this serves as a guide portion to guide the secondary air upwardly and eliminates a smoky period when the burner is passing from the pilot light stage to the stage of higher combustion. The primary air from the apertures l8 passes, upwardly through the aperture 2| and is mixed with the secondary air from the holes I! above the flange 19. The secondary air from the holes next above the flange or bafile I9 is upwardly directed by the upturned portion I911. Any tendency'to an intermediate smoky period at the time when the burner is being turned up for higher heating is prevented. Preferably the upturned flange l9a terminates about the level of the lowermost holes l1 above the baffle l9 and the baffle 19 may be positioned about half way between the row of holes l8 and the bottom row I1. I find that in practice this structure eliminates any smoky period which might otherwise ensue when the burner is turned up or the flame is increased from the pilot stage to the full combustion stage.

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

The use and operation of my invention are as follows:

In liquid hydrocarbon burners of the type herein described, it is desirable to provide a minimum turndown so that a flame so small as to be in effect a pilot light may be maintained in the lower portion of the chamber I. This results in a minimum use offuel and in a minimum heating effect when the device is not needed for fuel heating, without actually extinguishing the flame. I find that the baflie t9 when placed low in the mixing chamber and just above the lowest holes, permits a very low turndown. In order to obtain the low turndown, the baffle should be low in the chamber and should also have a relatively small central aperture 21. The smaller the opening and the lower the bafile, the lower is the minimum flame and the greater the turndown. That is to say, a minimum of fuel is employed. However, there is a critical point in the size of the aperture, taken in connection with the position of any particular baflie, in which the segregated space below the baffle will not permit or support starting combustion. In such case, it may be advantageous to lift or adjust the baffle.

Hence, I find it desirable to have the baffles which are readily upwardly removable so that combustion can be initiated, as for example by dropping a bit of lighted waste in the bottom of the pot.- For example, I may upwardly lift or tilt the member I9 out of the position in which it is shown in the drawing, and then start the fire. Thereafter I can drop the baffle back into place and once combustion has been inaugurated it will continue with the above mentioneddesired maximum turndown feature. It is also highly desirable to have the baiiie readily removable for cleaning purposes and for removal in the event that the operator wishes to substitute a new baflle.

I claim:

1. A burner for liquid fuel and the like including a generally cylindrical combustion chamber, means for supplying liquid fuel to the bottom of the chamber, there being a plurality of air inlets disposed within the wall of the chamber in three separate groups, one group widely spaced adjacent the bottom of the chamber on one level, another group more closely spaced at a plurality of levels intermediate the top and bottom of the chamber, a third group still more closely spaced on a single level adjacent the top of the chamber, a baflie plate supported within the chamber substantially closing it, having a central aperture, said aperture being bounded by an upwardly turned flange, the baflie plate being located above the first named group of apertures, the upwardly extending flange terminating substantially in the same plane as the lowest level of the second mentioned group of apertures, a centrally apertured baflie overlying the top of the chamber.

2. A burner for liquid fuel and the like, including a combustion chamber having a generally cylindrical sidewall and a bottom portion, means for supplying liquid fuel to the bottom of the chamber, said wall having a plurality of air inlets located in generally horizontal vertically spaced rows, a baflle plate supported within the chamber intermediate top and bottom thereof, and substantially closing it, said plate having an upwardly extending flange surrounding and defining a central aperture, the lowest row of air inlets being in communication with the space below said baffle plate, the upwardly extending flange terminating in substantially the same horizontal plane as the row of air inlets next above said lowest row.

3. A burner for liquid fuel and the like including a generally cylindrical combustion chamber, means for supplying liquid fuel to the bottom of the chamber, there being a plurality of air inlets disposed within the wall of the chamber in three separate groups, one group widely spaced adjacent the bottom of the chamber on one level, another group more closely spaced at a plurality of levels intermediate the top and bottomof the chamber, a third group still more closely spaced on a single level adjacent the top of the chamber, a baffle plate supported within the chamber substantially closing it, having a central aperture, said aperture being bounded by an upwardly turned flange, the lowest row of air inlets being in communication with the space below said baflie plate, the upwardly extending flange terminating substantially in the same plane as the lowest level of the second mentioned group of apertures, a centrally apertured baflie overlying the top of the chamber.

JAMES L. BREESE.

Images