US2401086A - Oil burner - Google Patents

Description

May 28, H' C' LlTv-n-E OIL BURNE R- F'iled Aug. 14, 1943 2 sheets-sheet 14 INVENTOR. HARRY 7. zr/'4,5'

H. c. LITTLE 2,401,086

OIL BURNER Filed Aug. v14,'1943 A May 28, 1946.

sheets-sheet- 2 INVENTOR. v HA //f y 5' LINZ E BY Patented May 28, 1946 UNITED STATES PATENT OFFICE 2,401,086 on. BURNER Harry C. Little, San Rafael, Calif. Application August 14, 1943, Serial No. 498,652

9 Claims.

The invention relates to oil burners and more particularly to that type of oil burner wherein fuel oil is introduced into a carburator chamber and therein vaporized by heat, and mixed with air to propel' combustion mixture and discharged for burning.

An object of the invention is to provide an oil burner of the character described affording improved heat output capacity for the size of the burner with clean, eflicient burning conditions.

Another object of the invention is to provide l an oil burner having quick starting and rapid oil vapor generating characteristics.

Still another object of the invention is to provide an oil burner which has an improved rapid response to changes in rates of oil input in changing `from high to low re and vice versa and which becomes quickly extinguished upon cutting off of the oil intake so as to reduce to a minimum the undesirable, low, sporadic. andV uncontrolled burning usually occurring in a burner of the present type when the oil flow to the burner is turned ofi. r

The invention possesses other objects and features of advantage, some of which, Vwith the foregoing, wlll be set forth in the following description of the preferred form ofthe invention which is illustrated in the drawings accompanying and forming part of the specification. It is to be understood, however, that variations in the showing made by the said drawings and description may be adopted Within the scope of the invention as set forth in the claims. y

Referring to said drawings:

Figure 1 is a vertical longitudinal sectional view taken through a burner embodying my'invention.

, Figure 2 is a transverse sectional view of the burner taken on the line 2-2 of` Figure l.

Figure 3 is a transverse sectional view taken through the combustion chamber associated with the burner, the plane o f the section being indicated bythe line 3 3 of Figure 1. 4

The oil burner 6 as depicted in the accompanying drawings consists of a container preferably of cylindrical shape dened by a bottom wall 1, a cylindrical side wall 8, and a top wall 9. Provided preferably in the bottom wall l and desirably centrally thereof, is an oil inlet opening i! to which an oil delivery pipe I2 is to be connected by means o'fV a tting I3. Air inlet means, here in the form of aplurality of openings Hl in the side Wall 8,- is provided for admitting air into the chamber for mixing with oil vapor formed therein preparatory to burning. Formed in the top i 'downwardly through the central portion of thev wall s substantially centrally thereof is av discharge opening I6, here bounded by an upstanding ange or tube i'l. The bottom wall 1 is preferably slightly dished to cause the oil to gather or puddle around the central portion of the bottom directly under the discharge opening IB.

Oil entering upon the bottom wall of the container is vaporized by reason of the heatto which the bottom of the burner is subjected, and the generated vapor is admixed with air entering the container through the openings Ul so as to provide a burnable mixture of yair and `oil vapor. As an important feature of the present invention, the burner is so designed and constructed as to set up within the container a circulation of the air and the oil vapor causing the latter to move container as indicatedby flow arrows i8, outwardly across the bottom of the container as indicated by. ow arrows I9, upwardly along the :side walls of the container as indicated by now arrows 2l, and thence inwardly across the under y side of the top Wall 9 as indicated by flow arrows 22. As will be noted from the drawings this circulation of air and oil vapor in toroidal'convolutions, directs the hot gases downwardly towards the oil inlet opening II and across the bottom of the pot where the mixture is enriched by oil vapor-after which the vapor and air undergo a considerable travel during which the air and vapor may become intimately mixed prior to passage out oi' the discharge opening i8. It is preferable in order to provide for a maximum capacity of the burner, that the circulation of the gas in the radially-directed toroidal convolutions aforesaid take place throughout the entire interlor 'of the container, and this is obtained in part by the design of the top wall 9 which functions to impart to the air and oil vapor moving along the under side thereof toward the center of the container a downward component of movement. A preferred method for obtaining this eifect is illustrated in the accompanying drawings and consists in the using of a. plurality of radial vanes 23 on the under side of the'top wall 9. These vanes are preferably formed integral with and depend from thetop wall and are positioned in substantially radial planes with respect to the vertical center line of the burner and extend radially from adjacent the opening I6 to adjacent the side wall 8. As will be noted rality of clrcumferentialJy-spaced radially extending inverted channels which increase in cirthe Asulting converging portant function in absorbing vapor and openings, rather than supports the primary cumferential width towards their outer ends. Cooperating with the provision of the vanes is the positioning and concentration of the air openings Il at the upper end of the wall 8 so as to direct incoming air horizontally into the pot at the under side of the top wall 9 between the vanes 23. As will be seen from Figure 1 of the draw' ings a plurality of three openings Ila, llb, and llc are arranged in a substantially vertical line but all are within the vertical dimension of the channel. Preferably these openings at the outer ends of the channels are the only air inlet openings to the container so that the total air input to the container is located directly under the'top wall 9 and within the confines of the channels. Itis also important to note'that this concentration and confinement or the openings at the top of the side wall B with the resultant low pressure produced hereat materially induces the upward flow of the vapor along the wall. Because oi the radial'pattern of the vanes and the reof the channels towards the center of the container, incoming air is crowded downwardly and out of the channel as the air moves towards the center of the container and the discharge opening I6. Thus there is imparted to ,a substantial portion of the air traveling inwardly through the channels a downward component of movement for establishing the circulatory movement within the container as above described.

The vanes 23 also provide another very imy heat from the air and oil vapor so as to restrain burning and facilitate mixing of the air and oil vapor in the channels.` In the circulatory effect above described, a substantial portion of the incoming air is forced downwardly to pick up oil vapor along the bottom of the container and the-air and oil vapor is induced as above yexplained to move up the side wall and back through the channels where a portion of the mixture vis again deflected downwardly while another portion is drawn on from the circulating gases and into the discharge opening I8 by reason of the reduced stack pressure. Thus in operation the mass oi air and oil vapor continues to circulate in the manner described gradually enriching the mass with oil passing off into the discharge opening for burning. Under normal operations some burning takes place in the container thus producing heat for vaporizing the oil and for accelerating the circulatory movement.' Due however to the cooling effect of the vanes, little or no burning `takes place within the channels. I have found that best results are obtained when three a. lesser or greater number of openings, are used at the outer ends of the channels and when the center of the three openings, lh, is made substantiallylarger than the upper and lower openings ma and idc. The arrangement oi the air openings in the manner describedV appears to have a substantial effect on the desirable circulating effect within the burner. The entering air streams have an ejector action, driving the gases inwardly through the channels and at the same time drawing the gases upwardly A as aforesaidalong the side Wall and into the chanmiddle row of openings, Mb, provide the main air jets as aforesaid and the air issuing therefrom combustion within the container. The top row of openings Ma provide air therebetween an the underside of the top wall 9 and pass into the discharge opening I8 for supporting the main secondary combustion above the burner. One important advantage in confining the air inlet openings to the top of the side wall 8 is the provision of an imperforate container over substantially its full height, thus effectively avoiding the danger of an oil overow from the container when the oil builds up from its usual depth on the bottom wall before the auxiliary automatic level control vaive'operates to shut oi the oil iiow.

Preferably and as herein illustrated means is provided for air cooling the top wail s of the burner so as to remove the heat absorbed by the vanes 23. When in the installation of the burner, air is permitted to freely circulate around and acrossthe top wall of the burner at the outer side thereof,I this effect can be accomplished. In the present burner, however, a cooling of the top wall 0 of the burner is obtained by passing secondary air across the upper side of the -top wall. As shown in Figure 1, the present burner is adapted for user with and is shown operatively connected tc a heater casing 2d providing a combustion chamber and including, of the portion here shown, a side Wall 28 and a bottom wall 21, the latter being here formed with a burner opening 28 for receiving the gases discharged from the burner. The burner may be secured in place under the heater casing with the discharge opening of the burner in lregistration with the burner opening of the casing, by any suitable means such as the mounting brackets 29 here shown connecting the lburner with the casing. As will be seen from Figis preferably supported with the top wall thereof spaced from the bottom wall 21 of the casing so'as to define an air space therebetween. In the preferred embodiment of the invention as herein depicted, the opening 28 in the heater casing is bounded by an upstanding flange 3| of somewhat greater diameter than the flange I1 on the top of the burner so as to define annular passage 32 which connects the passage 33 between the top wall 9 of the burner and the bottom wall 21 of the casing with the interior of the casing for supplying secondary air thereto.

ure 1, the burner yfunction to preheat the Asecondary air before the latter enters the y combustion chamber.

As another improved feature of the present construction, flame concentration means is provided at the upper end of the burner throat. .fis here shown, this means consists of a plurality of overhanging portions 3B which are positioned in substantially 90 spaced relation around the top perimeter of theflange 3i. and extend inwardly therefrom over the top or flange Il so as to dene a cross-shaped top opening for the burner throat. As will be best seen from Figure 3 the opposed edges''i and 38 of adlacent overhanging portions 38 are formed in substantially parallel relation thus functioning todirect air and oll vapor issuing laterally from the under side of the portions 36 at such edges .in opposite clashing streams producing intense and kconcentrated burning. The air passing over the inner side of ange Il and across the underside of the overhanging portions 36 protects these impingement and streams which for the most part are confined to to safe working temperatures.

In order to improve the heat ex- `change relation within the passage 33, I prefer draft, with very substantially improved operation,

by forcing the air through the openings I4 and the secondary air passage 34 by an elevated pressure. This may be accomplished by enclosing the burner or at least the air intake end of the air passages in a chamber or manifold connected to an air blower. In either case, whether natural or forced draft, the burner as herein described provides many important advantages over burners of this general type heretofore available. The burner starts readily on ignition of oil on the bottom thereof and rapidly generates sufilcient vapor to quickly pass through the early stages of burning to full operation. Due to the toroidal circulatory action within the burner, a minimum quantity of oil is present within the burner dur- 'ing operation and hence the burner is more responsive to changes in oil input throughout all operati-ng stages. Of particular advantage is the rapid extinguishment of the flame upon cutting off of the oil ow so as to reduce to a minimum the undesirable last minute, sporadic burning which usually occurs before the burner finally goes out. The circulatoryaction' of the gases within the burner produces an unusually high capacity for the size of the burner and insures better mixing of the air and oil vapor with resultant cleaner and more efficient burning.

I claim:

1. In an oil burner, a container having bottom and side and top walls, means for admitting oil to said container, means for admitting air to said container adjacent said top wall, said top wall having a discharge opening centrally thereof, means guiding said air along said top wall inwardly toward said discharge opening, said last means being provided with guide means to impart to air and oil vapor moving along the underside of the top wall towards the center of the container a downward component of movement so as to set up a circulation of toroidal convolutions of air and oil vapor within the container.

2. Inan oil burner, a container having bottom and side and top walls, means for admitting oil to said container, means for admitting air to said container, said top wall having a discharge opening centrally thereof, and a plurality of radially extending vanes mounted on the under side of said top wall and extending from adjacent said .side wall to adjacent said opening for guiding the movement of air from said side wall to said openmg.

3. In an oilburner, a container having bottom and sideand top walls, means for admitting oil to said container for heating and vaporizing and mixture with air for burning, said top wall having a discharge opening centrally thereof, a plurality of vanes carried by said top wall and extending radially thereon with respect to said opening from adjacent the outer periphery of said top wallto adjacent said opening, said side wall having openings for admitting air to said container through said side wall adjacent the outer edges of said vanes. I

4. In an oil burner, a container denedby a substantially cylindrical side wall and disc-like bottom and top walls, means for admitting oil to said container for vaporizing and mixing with air for burning, said top wall having a discharge opening` centrally thereof, a plurality of vanes mounted on and depending from said top wall and extending from adjacent said opening to adjacent said side wall, said vanes 4being formed and mounted in substantially radial planes with respect to the longitudinal axis of said container and providing a plurality of inverted channels each increasing inwidth towards the radially outer end thereof, said side walls beingformed with air openings at the outer ends of said chan-v nels, said air openings providing the exclusive means of air entry to .the container.

5. In an oil burner, a container having bottom and top and side walls, oil inlet means provided on said bottom wall substantially centrally thereof for admitting oil onto said bottom wall for vaporization and mixing with air for burning, said top wall having a discharge opening therein substantially centrally thereof, and a plurality of vanes mounted on and depending from said top wall and extending substantially radially with respect to said discharge opening from adjacent said opening to adjacent said side wall, said side Wall being formed with a plurality of air inlet openings adjacent the top thereof between said vanes for entry of air into said container horizontally across the underside of said top wall, said vanes functioning to crowd said air downwardly r adjacent the center of said container to set up a jacent said opening to adjacent said sidel wall,

and means cooperating with said top wall and defining an air passage at the outer side of said top wall from adjacent the outer periphery thereof to adjacent said-opening, and heat radiating means attached to said top wall and mounted in said air passage.

7. In an oil burner, a container having a bottom and side walls, means for admitting oil to said container, means for admitting air to said. container substantially exclusively adjacent said top wall, said top wall having a discharge opening substantially centrally thereof and spaced from said side wall, and means extending along the under side of said top wall for directing said air inwardly of said side wall toward said discharge opening and imparting a downward component of movement to air and oil vapors moving therealong.

8. An oil burner throat construction adapted for mounting, within a heater casing, for delivering an air and vapor mixture into said heater casing, comprising in combination with a casing and an oil vaporizing and air mixing chamber, a vertical annular wall having a lower end opening leading into the interior of said chamber and an upper end opening leading into said heater casing, a second vertical annular wall concentric with said first wall and defining therewith an annular air passage, said second wall extending higher than said first wall, and a plurality of opposed pairs of inwardly projecting coplanar portions extending from said second wall over the upper end of said first wall and the opening at such end, and spaced from said end a distance substantially corresponding to the spacing between said annular walls, the edges of adjacent projecting portions being parallel and dening branch passages from said rst air passage to y said heater casing.

9. In an oil burner, a container having bottom and side walls, an upper wall extending -inwardly from saidy side wall and above said bottom wall to form an oil vaporizetion chamber, l0

sages for directing air from said openings inwardly along said top`wa11 towards said discharge opening.

HARRY C. LITTLE.

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