US2502210A - Spray type oil burner with air directing means - Google Patents

Description

March 28, 1950 c. DEMUTH 2,502,210

SPRAY TYPE OIL B LJRNER WITH AIR DIRECTING MEANS Filed. July 15, 1946 INVENTOR.

CHARLES DEMUTH.

zthe fuel pump side;

. Patented Mar. 28, 1950 UNITED STATES PATENT OFFICE SPRAY TYPE oIL BURNER WITHAIR DIRECTING {MEANS Charles Demuth, MineolapN. Y. Application July 13, 1946;.SerialjNo. 683,482

/ This invention relates to burners for liquid luelpsueh'as oil burners, and theinvention is intended more especially for burners operating short-"and where it is desired to have a loose large-flame distributed as evenlyas possible over the-entire space, and of. course ascomplete combustion as possible is desired for fuel economy. These desirable characteristics require a large amount of air; and in attempts heretofore made tosupplyextra. air two undesirable results have *beenprominent. First too long a tongue-like close or compact flame, with a resultant roar and =a .ten'dencyto blow out the flame; and second .:a flamewhose propagation is. completed. immediately adjacenttheburner nozzle and hence not in the 'desired position. substantially centrally of the firebox or combustion chamber.

'An object of'this invention is toprovide an improved burner adaptedto supplysuflicient air "for complete combustion without tending to blow out the flame and producing a relatively large, open, quiet or lazy flame propagatedzat a dis- :tancein frontoftthe burner nozzle.

-Another objectof the inventionis to provide a burner capable of facile adjustment and con- -trol'of' the air supply, liquid fuel supply and'ignitionelectrodes.

Other-and further objectsand advantages'of "thekinvention will be apparentirom the follow- "ingdescription 'considered in-connection :with

the"accompanying'drawings, showing a present preferred form of the invention, in which:

i Fig. 1 is a side elevational View looking from "Fig. 2 is a planview of "the burner-shown in 1,'with'thetop coverremoved so as to'show certain parts disposed withinthe casing; and

Fig."3*is a somewhat enlarged crossasectional viewsof the nozzle'end of-the burner shown in SE'i-gs. 1' and 2, taken on a horizontal plane passing *throughithe central axis of the nozzle as. shown in Fig. 1. Referring more particularlytoFigs; land 2; a

2 suchas by the motor shaft 4. A suitable blower rotor, A such as a squirrel cage motor 5 is con- -6 Claims; ((31.158-46) vemently-mounte'd "on. the shaft 4. The housing is preferably'provided with a-suitably-shaped par titionsuch as fi providinga bottom wall for the rotor chamber and preferably spaced from the bottom 'ofthe housing to provide a compartment for accommodating 'a control switch or other suitable control mechanism'of the. character well known;-andairemovable rear door 1 provides access to this compartment. The housing I is also provided with a :removable top panel or door 8 comprising the entire top and part of the back wall of the housing'and held in closed position by suitable fasteners such as 9. The top, four sidewalls and partition 6 provide the blower chamberfor therotor 5. The sidewalls of the :housing are preferably provided with outwardly extending flanges such as 10 providing' feet for securing the housing'in position.

A cylindrical tubular member II is ri idly secured at its inner'endto the front wall of housing I near-its top, .as by welding, audits interior is .in communication with theblower chamber through an opening provided in the front wall. "A.slidably' adjustable panel I2 is-disposed over the-blower opening [20Lv (Fig. 1) in the side wall backrofthe pump '3, aroundthe shaft 4, to therebygprovide for regulating or Y adjustin'g theisupply ofair. tothe burner. nozzle.

Theair tube=H a(Fig. 3) is-provided witha forward abruptly outwardly flaring annular fiange'or lip 13-, "A second cylindrical tubular member :14, ofsubstantially smaller diameter than --.the-tube H, .is disposed concentrically within the tube Hand rigidly fixed in place. as by a .plural-ity-of oircumferentially spaced radially extendingxstrutsssuchas 15. The front end of the. inner air-ttube I4 is provided with a forward abruptly-outwardly flaring annular flange or lip 15. preferably-terminating at its forward end beyond the lipl3 *and cooperatingly disposed therewith toprovide an-annu-lar outwardly flaring orificefor secondary air. The inner tube I 4 is :also provided with 2'8, forward abruptly inwardly flaringvannularflange or lip l1 preferably terminating at .its forwardend beyond the lip l3 andprovidingarestricted air orifice for primary air. The rearen'dofthe inner-tube I 4 is turned inwardly to "PI'OVidBf-fli fr'ustro-conical portion I 8 .spacedqmxiallyforwardly ofzthe housing I. :A secondary-. air damper ring l9 is-slidably dis posed within-theouter; tube I I and is adjustably secured/in axial position byscrews such as 20 passing through axially :extending slots 2! in tuber. The ring [9 is .taperedto provide op- .positely disposed:frustroeconical sides the forward edge of which cooperates with the end I8 of tube l 4 to provide a variable area throat when moved from the solid line to the dotted line position.

A liquid fuel pipe 22 extends along the axis of the tubes H and I4 and at its forward end is provided with a nozzle tip 23 having an atomizing orifice which is disposed adjacent and preferably somewhat forwardly of the primary air orifice provided by the forward edge of the lip [1. The rear end of pipe 22 passes over the top of the rotor (Figs. 2 and 1), spaced upwardly therefrom, and thence laterally outwardly through a slot 24 formed in the casing wall and extending from its rear edge and terminating in a portion parallel with the burner nozzle axis and on the same horizontal level. The end of pipe 22 which is disposed outside said side wall is provided with an Lpipe fitting 25 having a hex portion 26 disposed against the outside of said walls, straddling said slot, and a cooperating lock nut 21 is threadingly engaged on said pipe and disposed adjacent the inside of said wall. When in operating position the pipe is rigidly locked to and supported from the side wall by the nuts 2B-21. This arrangement provides a facile means of adjusting the pipe and nozzle 23 in an axial direction; and also provides for removing the pipe and nozzle for cleaning or repair by disconnecting the compression coupling 28 (Fig. 1) to detach the flexible oil supply line 29. The pipe 22 is preferably supported intermediate its rear and front end by a suitable bracket such as 30 which is 'slidingly engaged within the tube II and is arranged to permit withdrawal of the pipe as aforesaid and which also serves as a mount for electrodes 3! whose forward firing points 32 are operatively disposed adjacent the nozzle 23.

Operation With the burner in operation, oil is supplied through the nozzle 23 and primary air through the air nozzle I! to produce a primary combustible mixture fired by the electrode points 32. This produces a primary flame somewhat of the form diagrammatically illustrated in Fig. 1 and designated 33. By adjusting the intake air damper I2 the primary flame may be adjusted to the desired extent which takes the usual form illustrated. Secondary air is supplied from the outer tube H and passes between the damper ring i9 and inner end I8 of the inner tube l4, and thence axially and divergently outwardly through the secondary air nozzle provided between the flanges l3!5 to provide an annular frusto-conical secondary air stream whose longitudinal sectional form is approximately illustrated diagrammatically in Fig. 1 and designated 34. This secondary air stream 34 surroundsor envelopes the primary flame 33 and is spaced outwardly therefrom for a substantial distance axially in front of the burner tip. As viewed in operation it is readily seen that the primary flame continues its normal form for some distance in front of the burner tip, and thereafter the final flame propagation takes place by the gradual supply to the primary flame of secondary air from the stream 34 to produce a large looseor lazy flame and resultant substantially complete combustion. The distance in front of the tip, where the final complete combustion takes place, and the regulation of the volume of air required for complete combustion, may be regulated by axially adjusting the ring damper I9. I have found that in the o'pen'position of ring IS the area of the'sec- 4 ondary air channel should be large enough to supply about 25% of the total air supply.

Having thus described my invention with particularity with reference to a preferred embodiment thereof, and having referred to certain modifications, it will be obvious to those skilled in the art, after understanding my invention, that other changes and modifications may be made therein without departing from the spirit and scope of the invention, and I aim in the appended claims to cover such changes and modifications as are within the scope of the invention.

What I claim is:

1. In a liquid fuel burner, the combination of an inner tube having an inwardly tapered orifice at its'forward extremity for supplying primary air, a concentrically disposed outer tube providing jointly with said inner tube an annular outwardly flaring orifice outlet mouth spaced outwardly from and surrounding said first orifice in spaced relation thereto for supplying secondary air in a diverging axial direction, and a liquid fuel tube within said inner tube provided with a nozzle whose orifice is disposed centrally of and adjacent to said primary air orifice, whereby upon combustion of said atomized liquid and primary air an axially directed primary flame is produced within an enveloping diverging secondary air stream to thereby produce complete combustion in a zone spaced forwardly of said primary air nozzle and provide a resultant relatively large flame.

2. In a liquid fuel burner, the combination of an inner tube having a restricted orifice at its forward extremity for supplying a primary air stream, a concentrically disposed outer tube providing jointly with said inner tube an annular outwardly flaring orifice spaced outwardly from said first orifice for supplying secondary air in a diverging axial direction, and a liquid fuel nozzle disposed centrally Within said inner tube and terminating adjacent to said primary air orifice, whereby when fuel is emitted into the centrally disposed primary air stream the resultant mixture is ignited and a first relatively dense axially directed primary flame is produced within and enveloped by the wider diverging secondary air stream and thereafter complete combustion takes place in a zone spaced forwardly of said primary air nozzle to provide a relatively large loose flame.

3. In a liquid fuel burner, the combination of an outer air tube provided with an outwardly flaring forward lip, an inner air tube coaxially disposed Within said outer air tube and provided with an inwardly directed peripheral forward lip providing a restricted orifice and with an outwardly flaring forward lip cooperatively disposed with respect to said outwardly flaring forward lip provided by said outer'air tube providing therewith an outwardly flaring annular orifice surrounding and spaced outwardly from said inner orifice, and a liquid. fuel tube extending in an axial direction within said inner tube and terminating at its forward end in a liquid nozzle whose orifice is disposed substantially coaxially within said inner air tube adjacent said restricted orifice.

4. In a liquid fuel burner, the combination of an outer air tube provided with an outwardly flaring forward lip, an inner air tube coaxially disposed Within said outer air tube and provided with an inwardly directed peripheral forward lip providing a restricted orifice and with an outwardly flaring forward lip and cooperatively dis- 76 posed with respect to said outwardly flaring forward lip provided by said outer air tube providing therewith an outwardly flaring annular orifice surrounding and spaced outwardly from said inner orifice, said inner tube being substantially shorter than said outer tube and having an open rear end in communication with said outer tube whereby said outer tube rearwardly of said inner tube provides a common conduit for said inner and outer orifices, and a liquid fuel tube extending in an axial direction within said inner tube and terminating at its forward end in a liquid nozzle whose orifice is disposed substantially coaxially within said inner air tube rearwardly of said restricted orifice.

5. In a liquid fuel burner, the combination of a cylindrical outer air tube provided with an outwardly flaring forward lip, a cylindrical inner air tube coaxially disposed within said outer air tube and whose forward end is bifurcated so as to present respectively inwardly and outwardly diverging peripheral flanges, said inwardly extending flange providing a restricted orifice and said outwardly extending flange being cooperatively disposed with respect to said outwardly flaring forward lip provided by said outer air tube providing therewith an outwardly flaring annular orifice surrounding and spaced outwardly from said inner orifice, said inner tube being substantially shorter than said outer tube and having an open rear end in communication with said outer tube whereby said outer tube rearwardly of said inner tube provides a common conduit for said inner and outer orifices, and a liquid fuel tube extending substantially axially within said inner tube and terminating at its forward end in a liquid nozzle having an orifice spaced axially from said restricted air orifice.

6. In a liquid fuel burner, the combination of a first air nozzle, a second air nozzle concentrically disposed surrounding said first air nozzle in spaced relation thereto, the outer extremities of said i first and second air nozzles jointly provid ing an annular outwardly flaring orifice for pro: ducing an outwardly directed divergent annular air stream, said first air nozzle also providing an inwardly tapered restricted orifice of a smaller diameter than and spaced inwardly from said outwardly flaring orifice, and a liquid fuel nozzle disposed centrally of said first air nozzle, whereby said liquid nozzle and first air nozzle produce a relatively long flame of the combustion mixture spaced within an enveloping air stream sup plied by said annular outwardly flaring orifice.

CHARLES DEMUTH.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 120,680 Smith Nov. 4, 1871 1,817,470 Adams Aug. 4, 1931 1,933,701 Blythe Nov. 7, 1933 2,057,783 Lattner Oct. 20, 1936 2,065,042 Berryman Dec. 22, 1936 2,078,021 Ro-dler Apr. 20, 1937 2,094,943 Gianola Oct. 5, 1937 2,133,485 Sherman et a1 Oct. 18, 1938 2,163,915 Rief et al June 27, 1939 2,215,272 OBrien Sept. 17, 1940 2,220,603 Hirtz et a1. Nov. 5, 1940 2,221,519 Jones et al Nov. 12, 1940 2,308,439 Carroll Jan. 12, 1943 2,325,444 Vroom et a1 July 27, 1943 2,344,519 Nagel Mar. 21, 1944 FOREIGN PATENTS Number Country Date 105,155 Germany Jan. 10, 1927

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