US2066806A - Oil burner - Google Patents

Description

Jan. 5,1937. JftsMlTl-l ET AL 2,065,806

y OIL BURNER Filed Dec. 2, 19:55 2 sheets-sheet 1 l JH/v SM1 TH A ND BY VIPs/L. f. Dusar/.ER

Jan. 5, 1937. J. SMITH ET AL l 2,066,806

OIL BURNER vFiled Dec. 2, 1935 2 Sheets-Sheet 2 INVENTORk 36 Y JH/v SM/TH AND 37 BY WPG/L E. .DUEMLER ATTORNEYS Patented Jan. 5, 1937 UNITED srivrEs PATENT OFFICE on. Burman Application December z, 1935, smal No. saisz 4 claims. (criss- 76) `This invention relates to improvements in oil burners.'

The invention has for an object the provision in a gun type burner of improved means for d1- 5 recting air to the oil, characterized by the production of a steady, stable and quiet name of high temperature and by improved eiiiciency ci combustion. I

More particularly, it is an object `of the in- .vention to provide in a burner wherein the air is fedto the oil in aplurality of generally concentric, annular streams, a novel form of spacing of the outlets, through which said streams issue, whereby an annular area of low pressure is created between said streams into which one oi them may in part expand and form, in eifect, an intervening stream of lessened velocity, thereby securing an improved and graded distribution of the air along the flame to effect prol sressive combustion.

Another object of the invention is to provide in a burner of the class described, means forcausing the outer air stream to whirl around the axis of theoil nozzle, and an arrangement whereby 2g an inner portion oi the outer air stream is enabled to expand radially inward and envelop the oil stream at a point close to but slightly beyond Athe location where the inner air stream meets the oilstream, and in the zone of gasiilcation of the oil,said inner portion of the whirling air stream acting to whirl the gasified oil in a zone between the oil nozzle and the normal zone of application of the outer air stream to the oil.

These and other objects will more particularly appear as the detailed description proceeds and will be pointed out in the appended claims.

The invention will be disclosed with reference to the accompanying drawings, in which:

Fig.v 1 is a side elevational view, partly in section of an oil' burner embodying the invention;

Fig. 2 is a fragmentary sectional elevational view, taken similarly to Fig. 1 but showing only the outlet end oi' the burner and drawn to a larger scale;

Figs. 3, 4 and 5 are cross sectional views taken on the lines 3 3, 4--4 and 5-5, respectively, of Fig. 2; and l v Fig. 6 is a fragmentary sectional elevational view showing a modification.

50 Referring to these drawings; the burner is of the pressure atomizing type, having a nozzle IIJ v,to which oil is supplied under relatively high pressure and from which the oil is emitted in a substantially hollow conical spray of finely A 55 divided. particles andA practically in the `form '.slot in the inner face of head IB, as indicated in of a mist or '-fog. This nozzle is secured to one end of a cylindrical support II and located near the open outlet end of an air tube I2, having atsuch end a deiiector I3 to` direct air inwardly toward the oil spray.' nir at relatively low s pressure is supplied to tube I2, near its other end, by afan I 4 driven by a motor I5,-the fan casing being located above tube I2 and formed as an integral part thereof.

The fan end of tube I2 is closed by a head I6 held in place by cap screws AI1 and capable of being easily removed to enable servicing of the nozzle I0 and aociated parts. A pair of rods I8 iixed inhead I6 by set screws I9 in a manner to enable 4adjustmentoi the rods in a direction longitudinally of the tube I2, extend forwardly in said tube and are suitably fixed, as by the screw threads shown in Fig. 2, to an air dividing and directing member 20 which is slidable in the tube. This member 20 supports a pair of insulators 2i, I, carrying the ignition electrode rods 22 which terminate in electrodes 23 positioned in igniting relation with the spray from ,nozzle Ill. The insulators 2i pass through and are slidably adjustable in a longitudinal direction in member 20 and are xed in their positions of adjustment by set screws 25 in member 20. A bracket 26 interconnects the two rods I8 and is adjustably ilxed to each by a set screw 21. The nozzle support II passes through bracket 26 and is iixed 6,., thereto by a set screw 28. Thus, by removing head I8, the nozzle I0, air director 20 and spark electrodes may be withdrawn as one unit, withoutdisturbing the relationship `oi? these parts.

Oil is supplied to the/nozzle by any suitable y, means, usually a pump (not shown) driven by motor I5, and passes 'through piping, indicated in part in Fig. 1 at 29, to the nozzle support II. The piping 29 enters the air tube through a radial Fig. 1. The support I.I is also an oil conductor. It isbored out, as shown in Fig. 4, to receive a rod 30 which has a longitudinal groove 3| in its `periphery and which lls the bore and closes it except for the' groove 3|. This groove intercon- 15 connection with the burner and is independent of them.

l The invention features a special construction of the air-directing member 2l. This member, in the form shown, is roughly cup-shaped, having an annular rear wall 34 disposed transversely of tube I2 and an integral and forwardly projecting annular ange or outer tubular part 35, mounted in spaced coaxial relation with tube I2 and forming an outer annular air pasage 31 of`relatively large area. The indenting of the front face of this member is'largely for the purpose of saving metal and except for the undesirable bulk, the member could be truly cylindrical. Integral vanes l36 project radially outward from the outer periphery of ange 35 at suitably spaced angularintervals and these vanes engage the inner wall of tube I2.A These vanes are inclined to the direction of the air flow in tube I2 and substantially of spiralform. They operate, as is well understood in the art, to whirl the air passing through the'passage 31. The wall 34 is bored out to receive a tube 38 having an internal diameter greater than the support II, which passes through it in coaxial relation, whereby an inner air passage 38 of annular form is provided. This passage 39 is relatively small in cross sectional area as compared to passage l1 and only a small portion of the air supply passes through it. The outlet end of the inner air tube I8 has iixedthereto a deflector or nozzle Il to direct the inner annular air stream toward the oil spray. The tube 3l is adjustable longitudinally in theair director and is held in adjusted position by a set screw 4I (Fig. 1). The nozzlesupport II is .supported at its forward and nozzle-.bearing Aend and centered in the tube 38 by three ns 42 which extend radially inward 'from the tube and engage the cylindrical part 43 of the support I I. The shoulder u on support I I is adapted to abut the ends of vanes 42 as shown. 'I'he vanes 42, as herein shown, are straight and parallel to the direction of air flow in tube I2.

In operation, the oil supplied under high pressure to nozzle III is emitted from the latter in the form of a spray of very nely divided particles and in substantially the shape of a hollowcone. Actually, the spray is almost like a mist or fog. Surrounding that 4portion of the spray which is visible, is a zone of invisible spray and the spark from the ignition electrodes usually extends only into the zone of this halo-like invisiblespray. Ignition occurs initially in this zone rather than in the visible part of the spray. The arc-like spark from the electrodes is distended by the outer air stream and blown into the invisible oil spray. The latter ignites in a flash which is almost instantaneously transmitted to the visible spray to ignitek the latter. The oil issuing from nozzle I0 rapidly expands and would spread out radially to inner air stream which envelops it at a location very close to the tip of nozzle Il. This inner stream initially is of relatively high velocity and 'acts to shape the oil spray and prevent undue manner.

The outer stream is caused by the vanes 36 to whirl or rotate and envelop the flame. 'Ihe outer and whirling air stream `at the point oi its emission (at the forward end face of tubular part 35) is spaced radially a substantial distance from the inner air stream, and there is a substantial space between these streams. Therefore, the

outer air stream, in part, expands radially inward toward tube 38 and flows forwardly along the same (as indicated in Fig. 2 by the arrows 46) y and then inwardly along the outer surface of nozzle 40 to meet the flame at a point close to the outlet of nozzle 40, or at about the point where the inner air stream loses its effectiveness on the flame. 'I'his action is, we believe, a very important factor contributing to the exceptional results in combustion which aregsecured from this burner. A portion of the whirling outer air stream is made to act onthe flame in a zone intermediate the two zones where the inner and outer air streams would act in a burner of conventional form. This portion of the outer air streamis made to whirl the gasified oil in the zone where the whirling has heretofore been effected by vanes in the inner air passage. Thus, one set of vanes accomplishes the work of the two sets often used. 'Ihe result is a necking down of the llame into more or less cylindrical form for a short distance, as illustrated at 41,-say

a littlebeyond the outlet end of deilector I3.

The zone between the latter and the nozzle is one of ignition and gasification. Here, the oil is gasified, as it must be in order` to burn, and combustion for the most part occurs lbeyond the defiector I3.\ Therefore, the part of the outer air stream which expands as described, acts on the gasifled oil in the gas zone, whirling it around and around to improve the mixture and hold the flame confined in the shape shown. Necessarily, this air has relatively low velocity in a forward direction because it is travelling in a spiral path and because it has expanded in a radial direction. (The arrows show simply the general forward direction-of the air vand no attempt has been made to show the actual spiral path of the outer air.) It thus tends to hold the oil longer in the zone of gasification and thereby much n .better and more thorough gasification and mix' ture-occur, as is evidenced by the bluish color oi' the flame in this zone. The oil is slowed up in its forward travel long enough to enable thorough gasification to occur. Naturally a condition of partial vacuum exists in the space between the outlets of the two air streams and this has a retarding effect on the flame and also tends to prevent it from drifting away from the nozzle I0, thus resulting in a very quiet and stable flame.- The outer portion oi.' the outer air stream follows the usual course (indicated roughly by the arrows 48) and meets and envelops the fiame-out- 76 proper amount of air supply. 'I'hefiame has a hollow center 50 in which there is some recycling 'of the products of combustion and here there is :liso a certain amount of turbulence indicated at It is to be particularly-noted that the arrangement described results in a very effective and graded air distribution. Instead of concentrating the air supply at two fixed zones, some of :the air of the outer air stream is fedto the flame at various points between these zones, thus distributlng the air along the iiame to .secure progressive combustion. v

'I'he air directing means also 'is eiiective over a wide range. Its construction is such that the results described are obtained with such means independently of-the amount of oil burned and thevelocity of the air, overa considerable range.

The arrangement also results in better comlbustion due to a more thorough gasification a'nd a 'more thorough and uniform mixing of the air and oil. A flame of higher temperature is secured-a highly radiant one and one of short bushy character.

` -The ameis exceedingly stable and quiet.

Ignition is sure and carbon- Vization is reduced to a degree where it ls prac- -tically negligible.

Eiilciency 'of combustion is very much improved as proved by actual tests. I'he relative longitudinal positions of the noz-yr zle Ill, cone 40, air director 20 and defiector I3 v nally relatively to'deiiector I3', asby loosening screws I9 (Fig. l) and pushing'rods Il more deeply into their sockets in head I-B or pulling them out fartherin such sockets. If such as' sembly is moved toward deilector I3, the flame is widened very decidedly and if moved backwardly.

lthe flame is narrowed slightly. The .cone "40 and nozzle Il l may be moved relatively to the air director 20 and defiector I3. To do this, screws 28 and 4i are loosened, ltube 40 is pushed back or pulled out to the desired degree in member l20. and support Il, is moved until the shoulder-44 abutsthe ends `oi.' vanes 41, when the nozzle I6 and cone 40 will be in the same yrelationship as` formerly. 'I'he eii'ect of such movement, if backward, i's to narrow the ilame and, if foward. to broaden the flame. The nozzle I0 maybe adjusted longitudinally without moving .the parts I3. 2li and 40, by'loosening the screw 2l and moving the nozzle support Il. The nozzle should not be moved rearwardly from the illustrated position. It might be moved forwardlyrprovided that the locating plan described.' involving ab'utment of shoulder 44 with the ends of vanesv 4I were dispensed with.- The effect would be to broaden out the flame. `Other adjustments may be made, if desired.- For example, the element 2l may be moved toward or away from' the deflector I3 leaving the cone 40 andnozzle Il positioned as shown, but theones above enumerated are the most desirable ones and those usually used.

It should be particularly notedl that the means used to space the inner and outer air streams so thatpart of the outer stream can expand and form an intervening str eamof less velocity, enable another desirable result to be obtained. The electrodes' and their insulators can be passed through the annular wall 34 and thus kept out of v the air' passages. Necessarily, if these elements were inserted in air passage 31, they would interfere with the equal distribution of air flow to the flame. By'the present arrangement, the electrodes and their insulators are kept out of 'the way where they have no deleterious effect on the air streams.

'I'he inner Vairstream may be whirled, as by the vanes 49 shown in Fig. 6. The ordinary advantage of whirling this stream has been secured by the arrangement described,whereby the .whirl- .ing effect of -the outer streamis transmitted toa location close to the nozzle where it can V'.do'much` not desired. Where conditions are such as to `because their use results inl expanding the name into saucer-like form, which in most cases is l,

make a flame of this shapedesirable, lthe vanes 49 can be usedto advantage.

'I'he ,invention provides an improved form of air dividing and directingmeans in cooperative relation with the oil nozzle and results in a better y mixing of the air and oil 'with resulting greatly improved combustion, and inthe production of a iiame which is short and bushy in form, consistently steadyv and stable, quiet. and of excellent quality.

What we claim is:

1. In yan oil burner, a tube through which air-is supplied Aand having a contracted outlet end, a nozzle for emitting a substantially conical spray of oil, said nozzle located in said tube near the outlet end thereof, an inner tubular member'surrounding said nozzle in spaced relation forming an annular passage through which air iiows and from which it is directed to the sprayed oil in a.

zone near the nozzle, an outer member spaced in-y wardly from said tube to form an outer annular passage through which air ows to said contract- .ed outlt and is directed to the sprayed oil beyond said zone, a partition connecting said members and blocking iiow of air except through said passages, and .means for whirling the outer air stream, said passages being radially spaced sumciently to create a substantial annular space between them into which the inner part oi' the outer air stream may expand and form an intervening annular air stream of less velocity than the outer part of the outer air stream.v

2. In an oil burner, a tube through which air is supplied and having a contracted. outlet end, a f

nozzle for emitting a. substantially conical spray of oil, said nozzle located in said tube near the outlet end thereof, an inner tubular member surrounding said nozzle in spaced relation forming an annular passage through which air iiows and said zone, a partition connecting said members' cept through said nur and blocking flow of airl sages, and means for" whirling the outer air stream, the outlet end oi' the outer air passage being substantially separated in a radial'direcg5 tion and spaced rearwardly in the tube from the outlet end of the inner passage. whereby the whirling outer air stream as it leaves the outlet of the outer air passage may in part expand radially inward and mix with the sprayed oil in a zone adjacent the outlet of the inner air passage.

3. In an oil burner, a tube through which airis supplied and having a. contracted outlet end, a

nozzle for emitting a substantially conical spray of oil, said nozzle located in said tube near the -outlet end thereof, an inner tubular member surbetween them into which the inner part of the outer air stream may expand and form an intervening annular air stream of less velocity than the outer part of the outer air stream.

4. In an oil burner, a tube through which air is supplied and having a contracted outlet end. a nozzle for emitting a substantially conical spray of oil, said nozzle located in said tube near the outlet end thereof, an inner tubular member surrounding said nozzle in spaced relation forming an annular passage through which air flows' and from which it is directed to the sprayed oill Y in a zone near the nozzle, an outer member spaced inwardly from said tube to form an outer annular passage through which air flows to said contracted outlet. and is directed to the sprayed oil beyond said zone, and a partition connecting said members and blocking' ow of air except through said passages, the outlet end of the outer air passage being substantially separated in a radial direction and spaced rearwardly in the tube from the outlet end of the inner passage, whereby the outer air stream as it leaves the outlet of the outer air passage may in part expand radially inward and mix with the sprayed oil in a zone adjacent the outlet of the inner air passage.

JOHN SMITH. VIRGIL E. DUEIMUJER.

Images