US2635009A - Oil atomizer for burners - Google Patents

Description

Patented Apr. 14,. 1953 UNITED STATES PATENT OFFICE OIL ATGMIZER FOR BURNERS Philip L Knight, Toledo, Ohio, assig'nor to Surface Combustion Corporation, Toledo, Ohio, a

corporation of Ohio Application May .22, 1948, S.erial.No.;28,5.83

1 `Claim.

pended thereto.

-In the accompanying drawingsrforming'part of lthis specication- Fig. l is an axial sectional view of the Aimproved oil converting devicewith an intermediate uportion broken away.

Fig. r2 is a cross section on line 2-2 of Fig. Vl.

Fig. 3 shows an alternative form of a part `ern-- bodied in Fig. 1.

Fig. 4 shows still another alternative form of a part embodied in Fig. 1.

Fig. 5 shows a modiiied form of Fig. 2.

Figs. 6 to 9 each shows a different kind of gas Y burner with the present invention applied thereto.

In the present invention, the apparatus comprises arelatively slender tube or nozzle I0 from which the oil issues in a finely divided .state in a high velocity carrier stream of 4gaseous medium which will ordinarily be air under pressure rather than steam because of its ready availability. The tube I0 extends from a hollow head II to which air under pressure is delivered by asupply .pipe I2 and to which oil is delivered by a metering nozzle lI3 mounted in! an end wall of the head, .the oil being delivered to the nozzle under pressure by an oil supply pipe I4. The metering nozzle is of :conventional atomizing type .and the oil issues therefrom as a fine spray.

The metering nozzle I3 discharges into an :oil Acollecting barrel I5 which ,in turn delivers to the said tube I0, the barrel being screwed into the V .head II 'and having its inlet and terminating short of the end wall wherein Vthe metering noz- :zle is positioned. Because the oil issues ,from the Vsaid metering nozzle as a fine .spray it will be readily appreciated that on striking the inner'wall .surface of the barrel it tends to convert to a thin layer or film thereon and therefore that it is the 'gaseous medium ilowing through said barrel I5 and tube I0 with relatively high velocity that moves the'oil along said surface and along the inner surface ofthe tube I0. The space I6 within the head II to which the air supply pipe I2 delivers is annular and thereforeV the air flows 2 Y into the intake Vend of the ibarrel .I5 byiinitially flowing across the rim thereof next adjacent the metering nozzle I3 and thereby tends to help in directing spray from said nozzle into said barrel.

Threads 2B on an exterior p-ortionof the head I I permitit to be secured to a support ,associated with the gas burner which is to be converted to burn oil. However, instead of the head itself being thus threaded, the threads may be provided on an outwardly extended portion,2;| ofthe barrel I5 (see Fig. 4).

Bearing in mind that a gaseous propelling `medium for the oil must also ilow through the tube I0, the oil feeding capacity of said tube, other things being equal, is directly dependent Von the lperimeter of the bore .of the tube rather .than

on the cross sectional area thereof. In .cases where the oil feeding capacity of the said tube I0 is relatively small (as for vexample where `the bore of the tube has a diameter of about Vonesixteenth of an inch which may be taken to be the size of the bore of the tube I0 in Fig. 3) it is not necessary to provide any special flow restricting orifice at the discharge end of the tube to insure that the oil shall be ejected from the tube Vin nely divided state, primarily for the reason that in a relatively small tube the ycenter oi? the air stream is not sufficiently remote from the oil film on the tube to permit any substantial lquan,- tity of the air to Yescape without exerting an atomizing effect `on the oil film as the latter is ejected from the tube. On the other hand, in the larger size tubes ID, the greater is the quantity of air which tends to escape from the ycenter of the air stream Without doing its quota of work on said lm of oil. To reduce this wastage of high pressure air to a minimum in the larger size tubes, the present invention provides a disk-.type

Y baffle or ,iller 22 vat the discharge -end of the tube whereby to restrict the lnormal .discharge area lof the tube to an annular type of discharge orice 23 of relatively narrow width. As shown in Fig.. 2, the said orice may consist of a circular series of relatively small size holes 24 or :as shown in Fig. 5 it may consist of a series of notches 25 in the rim of the balle. vBy thus reducing the .escape of air from the center `of the airstream, only a relatively small proportion (say not more than one-fth) of the air for complete combustion of the oil need be passed through the oil tube I0 to obtain the necessary propelling and atomizing effect on the oil, it being understood that the additional air for complete combustion being otherwise supplied as will more fully appear hereinafter. It will also be understood that because the oil issues from the tube i already dispersed in a stream of air the resulting flame of combustion will be much shorter than would be the case if steam instead of air were used to propel the oil through the tube.

The practical application of the invention is shown in Figs. 6 to 9. In each of these views a portion of the wall of an industrial furnace is indicated at 26, the wall comprising a refractory block 21 formed with a combustion tunnel 3!) to which the gas burner delivers.

In Fig. 6, a gas burner comprises a nozzle 3l from which the gas admixed with its full complement of air for complete combustion is delivered directly to the combustion tunnel 30, the mixture being delivered to said nozzle by a tube 32 to which a mixture supply pipe 33 delivers. A premix pilot is indicated at 34. To convert the burner over to oil, the oil tube I9 is inserted part way into the nozzle 3l by screwing the tube supporting head Il into the outer end of a pipe T 35 which interconnects the burner tube 32 and the mixture supply pipe 33. The supplemental air for complete combustion of the oil is delivered to the burner tube 32 by a supply line which will ordinarily comprise the pipe 33 and thence flows to the combustion tunnel 30 by way of the burner nozzle 3l as will now be readily understood.

In Fig. 7, the burner comprises a mixing tube 35 which discharges directly into the combustion tunnel 30. To convert this burner over to oil, the oil tube l0 is inserted part way into the said mixing tube 35 by screwing the extension 2i of the tube supporting head Il into the support 31 in place of the gas discharge nozzle which normally discharges into the mouth of the mixing tube 36from said support. In a converted gas burner of this type the tube I9 is small enough to permit the necessary secondary air to be drawn into the mixing tube 36 around the oil tube by the suction effect of the air and oil mixture issuing from the oil tube l0.

In Fig. 8, the burner comprises a mixing tube 4I!v set to discharge into the combustion tunnel 30 across an intervening air space. To convert this burner over to oil, the oil tube l0 is inserted into the said mixing tube 40 by screwing the supporting head thereof into the support 4l in place of the gas discharge nozzle. The necessary additional air for complete combustion of the oil is drawn into the combustion tunnel 30 by the velocity of the air stream from the tube l0 as it flows towards the tunnel across the intervening air gap.

In Fig. 9, a gas burner comprises a mixing tube 42 which delivers directly to the combustion tunnel 30. A premix pilot is indicated at 43. The air-gas mixture is formed by delivering air under pressure to the mouth of the mixing tube and by delivering gas at atmospheric pressure about the tube for ow thereinto through radial gas inlet ports 44 intermediate the ends of the tube. The gas supply pipe is indicated at 45, the same delivering to a chamber formed by a casing 46 around the mixing tube proper. The air supply pipe is indicated at 47l the Same d6- vlivering to the mixing tube by wayv of a passage tively simple Vand practical method and apparatus for atomizing oil for burners and which is very useful in converting many types of gas burners overrto oil. Certain of the apparatus herein disclosedV but not claimed is disclosed andclaimed in my application Serial No. 15,326 filed March 17, 1948, now Patent No. 2,518,025, granted August 8, 1950.

What I claim is:

A device for use with burners comprising, in combination, a hollow head defining a chamber for gaseous medium Linder pressure, an oil inlet to said chamber consisting of a metering nozzle of the atomizing type for discharging oil into said chamber in a fine spray, and an imperforate oil conducting tube having an inlet end, an outlet end, a relatively unrestricted tube passage therebetween and at its outlet end at least one relatively small discharge orice,'said tube being mounted on said head axially aligned with and spaced from said metering nozzle to receive oil therefrom and gaseous medium from said chamber, whereby said oil is substantially converted to a film within said tube, propelled as such through the passage thereof and atomized upon discharge therefrom by said gaseous medium as it passes through said discharge orifice.

PHILIP L. KNIGHT.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 275,124 Blumenberg et al. Apr. 3, 1883 370,251 Field Sept. 20, 1887 760,729 Camp May 24, 1994 818,030 Kirkwood Apr. 17, 1906 910,267 Billow Jan. 19, 1909 1,061,627 Nice May 13, 1913 1,241,135 VMastenbrool: Sept. 25, 1917 1,304,402 Spire May 20, 1919 1,400,657 Brodie Dec. 20, 1921 1,636,597 Fischer et al. July 19, 1927 1,659,573 Lalor Feb. 21, 1923 1,663,045 Gibson Mar. 20, 1928 1,712,326 Brock May 7, 1929 1,754,828 KelsallY Apr. 15, 1930 1,797,570 Ferguson Mar. 24, 1931 1,799,459 Fantz Apr. 7, 193.1 1,826,776 Gunther Oct. 13, 1931 1,860,942 Morse May 31, 1932 2,283,658 Westcott et al May 19, 1942 2,333,531 Ferguson Nov. 2, 1943 2,518,025 Knight Aug. 8,. 1950

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