USRE19176E

USRE19176E - Oil burner

Info

Publication number: USRE19176E
Authority: US
Publication date: 1934-05-22

Description

L. F. PEAR OIL BURNER Original Filed Oct. 12. 1951 2 Sheets-Sheet 1 Q INVENTOR. LEOLVN ESPEAR ATTORNEYS.

ll L L. F. SPEAR OIL BURNER Original Filed Oct. 12, 1931 2 SheetsSheet 2 INVENTOR; .LEuYNFSPEAR BY 49 MM ATTORNEYS.

/l rl changed from the usual able way, as by an electric spark produced between electrodes 21 (Figs. 1 and 8). If desired, these electrodes may be located out of the direct path of the oil spray and if necessary, the air stream will blow the arc-like spark into the oil spray to vaporize and ignite the same.

According to this invention, the oil nozzle is not directly supported from the bridge 13 but through the intermediary of a shield member which enables a substantial reduction in the heat transferred by conduction from the air head 12 and its bridge 13, protects the nozzle 14 from the direct heat of the furnace and provides for the admission of air streams around the nozzle and between the shield member and bridge for cooling purposes.

This shield member, shown separately in Figs. 2 to 5 inclusive, comprises a hollow cylindrical body 22, the front end of which is partially closed by a conical wall 23, leaving a central circular opening 24 through which the spray from ward extensions 25 of roughly skeleton triangular form, one of which has an upstanding and perforated lug 26. The openings through the extensions allow equalization in pressure of the air streams flowing on opposite sides thereof. Inside the hollow body 22 are four ridges 27 extending radially inwardly a short distance for contact at spaced points only with the nozzle, or some supporting part therefor such as the cylindrical member 28 connected therewith. The central perforation in bridge 13 is of a diameter such as to closely flt the cylindrical body 22 of the shield (Figs. 8 and 10). The shield is inserted in this opening and secured to-the bridge by a screw 29 through the perforated lug 26 into the back wall of the bridge (Figs. 1 and 7). The body 22 closes the central-opening in bridge 13 except for two diametrically opposed passages formed between the bridge and body by notches 30 formed in the periphery of the body (Figs. 8 and 10). At the rear end of each extension 25 are raised portions 31 which contact with the bridge. The nozzle is supported within the shield on the four ridges 27 in spaced concentricalrelation, leaving channels through which air can flo'w around the member 28 and nozzle 14 to the front end of the shield where it is emitted in an annular stream through the central opening 24, being deflected inwardlyby the conical wall 23 and caused to sweep across the face of the oil nozzle 14.

It is to be noted that the shield is supported from the bridge 13 so that it has only a very small area of contact therewith. By so doing, the transfer of heat by conduction from the bridge to the shield is minimized The shield has only four areas which contact with the bridge, viz., the 1 two small areas of the portions 31 at the rear and two small areas of the body 22 at the front. The rear edge of such bodv is curved as at 33, to approximate the configuration of the line of intersection between the cylindrical body 22 and the curved outer face 200: bridge 13, except at the center where a bearing spot 34 is provided.

to serve the purpose and is spot welded As will be seen from Fig. 9, the curved edge 33 substantially coincides with the aforesaid line of intersection and lies just enough back of it of preventing escape of air. This leaves only a small area for contact with the bridge and mainly that due to spots 34. The curved edges 33 are also important for the reason that they direct the air streams to the side openings 30, avoiding eddies and the like which would interfere with the desired smooth flow of air to such openings.

It is also to be noted that the nozzle 14, or more properly its attached member 28, is likewise supported from the shield in a similar way. The

member 28 bears on the shield only at the four 1 places 27 and each of these is of small area. It will be clear that the transfer of heat from the bridge to nozzle by direct conduction is materially reduced and cut down to a relatively small amount. In addition to restricting the transfer of heat to the aforesaid parts, means are provided for cooling them as air will flow all around the body of member 28, except for the small areas in contact with ridges 27, and all around the body of the nozzle 14 and across the tip end thereof. Also air will flow between the shield and bridge, except for the small contacting areas 31 and 34, such air being emitted from the side passages 30. The conical front wall 23 of the shield protects the nozzle 14 from much of the direct effects of the heat of the furnace, to which it otherwise would be subjected, and this wall is also cooled to some extent by the annular air stream flowing along its inner surface. I prefer to have the outer surface of this wall and the exposed cylindrical surface of the shield polished in order to minimize the deposit. of carbon thereon. A surfacereflects rays and does much heat as a rough and dark surface. And'the cooler the surface is kept the less likelihood there is of carbonization.

tional details of the burner. The air.tube 10 is desirably constructed in three parts,a front section 35 of true tubular form and upper and lower

rear sections

36 and 37, respectively, which are enough larger in diameter so that tion can be partially telescoped within them. The lower rear section 373s semi-cylindrical in form to the front section 35. It is also secured to the supported by a standard shown in part at 38. The upper rear section 36 constitutes a removable cover. It is semi-cylindrical in form except for the flanges 39 along its lower edges, which flanges overlap the lower section 37. The cover section 36 is held in place by two screws 40; When cover 36 is removed, the air head, oil nozzle,

spark electrodes and associated parts may bev drawn back into the rear section of the air tube has a sliding lit at the front end of the air tube with a ring 41 secured therein, and the head is connected to and held in place by a bracket 42. This bracket is secured to section 35 by a bolt 43 passing through an. open ended slot 44. By removing bolt 43, the bracket may be drawn back, carrying with it the air head and all associated parts in assembled relation. As soon as the air headis drawn back far enough to free it from ring 41, it will slide freely since it then fits only loosely in tube 35. There is preferably a shoulder 45 on the head to abut ring 41 as a stop for the purpose of locating the head in proper position pipe 54',

and" of making more difficult the escape of air between the head and ring 41. The head has two rearwardly extending studs 46 flxed thereto which pass through bracket 42 and are fixed thereto by set screws 41. In the center of this bracket is a cylindrical hole 48 (Figs. 1 and 6) in which is seated a spider 49, having flanges 50 to abut the rear face of the bracket. A set screw 51 (Fig. 6) holds the spider in place in the bracket and the oil pipe 15 is held in place .in the spider by a set screw 52. This oil pipe is connected'by a union 53 (Fig. 1) to an oil supply pipe 54 through the intermediary of a section 54 and two detachable connections 53 and 53 of anysuitable form. The section 54' is preferably somewhat flexible and is usually in the form of a copper tube having a bend therein as shown. The spark electrodes 21 pass through and are suitably fixed in position in insulating tubes 55, which each pass through the bracket 42 and are fixed thereto by set screws 56. The electrodes carry terminals 5'7 at their rear ends for connection'to ignition wires (not shovm) It will be seen that when cover 36 is removed, access may be had for disconnecting such wires from the terminals 57, for discormect ing connections 53 and 53' and removing the oil and for removing bolt 43. Then, the bracket 42 may be pulled rearwardly and lifted through the open upper end of the rear section of the air tube. Also, the oil nozzle may be removed without removing the air head, if desired, by loosening set screw 54 and drawing the spider 49 out of hole 48, carrying with it the pipe 15 shield of this invention.

. of circular cross and attached nozzle 14. i

The operation, broadly is like that of the burner of said patent but it is to some extent modified and improved by the use of the'nozzle alter the action so far as the flat flame effect is concerned. Such air issues in an annular-stream section in enveloping relation "with the oil spray which is at that time of hollow conical form. The "larger volume of air, which is divided into the two opposing and converging streams, does not. impinge on the oil spray until it reaches a'point somewhat ahead of the tip "of nozzle 14'and these streams .will do their work as effectively notwithstanding that the oil spray is enveloped by an annular air stream. Such annular air stream is a help in the same way that itis a help in the ordinary type of mechanical atomizing burner, where the main air stream 20 v of bridge 13.

is annular rather than divided into two flat sheets, as herein shown. These two flat streams, iri'impingin'g on the oil spray, tend to squeeze the latter between them and create a"certain amount of' back pressure and some small particles of oil can and do-accumulate on the nozzle and bridge. Ordinarily, without the shield of this invention, this back current causes oil spray to deposit on the nozzle tip and on the wall The convex outer surface of this bridge is a help in minimizing such trouble at points above and below the oil nozzle but it does not entirely cure the trouble at points to the right and left of the nozzle in the central the air streams which issue at the sides of the shield through openings'30. Also, the central annular stream of air through opening 24 helps byswccpmg into the main volumeof the air stream the particles of oil which would otherwise become deposited on the bridge and nozzle. The small air streams issuing at the sides of The air emitted through the central opening 24 in the shield does not for this purpose I employ the neutral territory between the impinging streams, the side streams would interfere to some extent with the flat flame cfiect. The extent of interference varies inversely with the amount of oil and air consumed by the burner. In burn-- ers using a relatively large amount of oil, there would be so much air supplied by way of the impinging air streams that the interference therewith by the small side air streams would be negligible. But in small burners like the present one, where only a relatively small amount of oil is burned, the interference is appreciable and hence the necessity for the described location of the side air streams. The air supply is relatively small and so small that the action of the impinging streams would be detrimentally affected by the small auxiliary air streams if these issued at any points such as to deflect the main air streams. For example, if air were admitted all around the outer periphery of. shield 22, the flat flame effect would be impaired because the annular air streams at certain points would deflect the main air streams out of their intended directions.

The action of the flat flame burner is actually improved by the use, of the nozzle shield because a better lateral distribution of air is effected. Heretofore, there was a tendency for too much air to go to the center and the flame produced tended to assume somewhat of a flshtail shape. That is, there was a hollow center in the central rear portion of the flame near the nozzle. .To overcome this, the shield is made .to project materially beyond the bridge 13 and the -path of the main air streams. Part of such streams strike the cylindrical projecting portion 22 of the shield, both from above and below, and such parts are divided, flowing some to the right and some to the left of the shield and oil nozzle. Less air goes to the center and more to the sides and a marked improvement in the lateral distribution of air results. The auxiliary side air streams at 30also feed air at points to the right and left of the I oil nozzle where air is needed.

partially into These two provisions result in a better and more divided, as just described, by the upper and lower peripheral portions of the "shield, a suction is produced between the divided air streams; This suction assists in producing an intimate mixture of the oil spray and the air streams and in 'sta-' bili'zing the ignition. zone. Combustion is materially improved thereby.

Itjwill be seen that the invention provides meansf'or counteracting the backward eddy of oil spray which is peculiar to the burner described, where the air is fed to the oil spray in two flat converging streamsfas distinguished from the usual feed of air equally -all around the circle of the, spray. This avoids much of the carbonizing of the nozzle 14 and bridge 13 which would otherwise occur. The polished conical wall 23 of the shield also protects the nozzle itself from much .of the carbonization which might otherwise occur. The remaining provisions for keeping down 'carbonization depend on the cooling effect of the parts. The'transfer of heat to the nozzle from the bridge is kept down by the reduction in the area efiective for conduction of heat between these parts. Also, air is admitted between streams, is also kept free of oil particles by the sweeping efi'ect 'of such streams. Thenozzle is thus kept cool by three different expedients. Conpurposes, but the scope duction of heat from the'bridge is reduced; refiected heat from the furnace to the nozzle is reduced by the coverage due to the conical wall 23; and air is admitted all around the nozzle to I cool it. Itistobe noted that when the burner fiow does not entirely cease because draft of the furnace willcause some through the described passages'for stops, the the nature air to flow cooling purposes.

It is most important to keep the nozzle cool. If it is allowed to get hot, the heat will crack the oil within the nozzle and a residue will be depositedtherein. Itisalmostvitaltokeepthenozzle cool if carbon deposits therein are-to be avoided.

Also, if the nozzle is 'ot, the oil in it expands after the burner stops and drips over the ex-' ternal face thereof. There is atthat time no atomization of such oil and it carbonizes. Deposited carbon acts like a wick and absorbs more oil which carbonizes and adds to the trouble. The blackened nozzle becomes even hotter because the. rough black surface absorbs more heat rays than a bright polished surface. and eventually a heavy layer Oil absorbed by such layer burns like a smoky torch after the burner has stopped still further heating the nozzle and making the'conditions worse.

The shield avoids, or at least substantially reduces, carbon troubles as above described. It also, by its special design cooperates in a special manner with the special type of burner described j and materially improves the operation as above set forth.

The invention has been I embodiment at present preferred, for illustrative of the invention is defined by the appended claims rather than by the foregoing description. 7

I claim: 7

1. In an oil burner, means for producing a substantially conical spray of oil, means for supplying air to the oil spray 'in two main streams one on each of two opposite sides of said spray and for directing said streams in forwardly converging of carbon is formed.

relation so as to impinge on the spray'after it leaves the first named means. and means for admitting additional air from each of two opposite sides of the first named means which last named sides are located substantially at right angles to the first named sides. v

V 2. In anoil burner, means for-producing a substantially conical spray of oil, means for supplying air to the oil spray in two main streams one on each of two opposite sides of said spray and for directing said streams in forwardly converging relation so as to impinge on the s ray after it The action continues" named passages -located angles to the first named passages and communi-.

leaves the first named means, and deflecting means located one on eachof said two sides and adjacent said first named means and extending into the path of said air streams at the central portions thereof for divinding the same at least ing air to the oil spray in two main streams one on each of two opposite sides of said spray and* for directing said ing relation so as leaves the first means located one on each adjacent said first named part way into the path of central portion thereof for dividing portions of the air in such streams and creating betweensuch portions a "suction effect at the central portion of the spray.

4. In an oil burner, means for producing a subof said two sides and 'stantially conical spray of oil, means for supplying air to the oil spray in two main streams one on. each of two opposite sides of said spray and for directing said streams in forwardly converging relation so as to impinge on the spray after it leaves the first named means, and means for admitting an annular stream of air around said first named means to impinge on the oil spray before said spray is subjected circle of the spray action of the first namedair to the impinging streams.

5. In an oil burner, means for producing a substantially conical spray of oil, means for supplying air to the oil spray in two main streams one streamsin forwardly convergto impinge on the spray after it named means, and deflecting means and extending" said air streamsat the substantially uniformly at all points around the to impinge on the' spray after cle of the spray before'said spray is subjected to the impinging action of the first named air streams, and means for admitting air in direc tions parallel to erture and two diametrically disposed air pas sages between the shield and said head, said last substantially at right eating with said central opening and thus with said conduit, and a mechanical atomizing nozzle mounted within said hollow shield and arranged to emit through said central aperture a substantially conical spray of oil.

'I. In an oil burner, an airconduit, a closure' head mounted in the outlet end of said conduit and having a central axial opening therethrough and two diametrically opposed air outlet passages therethrough disposed. one on each ,side of said central opening, a hollow shield having a central the axis of the spray-and on op-. posite' sides thereof, which sides are.located at 1 right angles to the first named sides.

losed herein, in an and mounted in said central opening aperture and closing the same except for said aperture and two diametrically disposed air passages between the shield and said head, said last named passages located substantially at right angles to the first named passages and communicating with said central opening and thus with said conduit,- and a mechanical atomizing nozzle supported within said shield in spaced concentrical relation and arranged to emit through said central aperture a' substantially conical spray of oil, the interior of said hollow shield communicating with said central opening to permit air from said conduit to flow around the nozzle and be emitted from the central aperture in said shield.

' 8. In an oil burner, an air conduit, a closure head mounted in the outlet end of said conduit and two diametrically opposed air outlet passages therethrough disposed one on each side of saidand having a central axial opening therethrough and two diametrically opposed air outlet passages therethrough disposed one on' each side of said central opening, a hollow shield having a-central aperture and mounted in said central opening and closing the same except for said aperture and two diametrically disposed air passages between the shield and said head, said last named passages located substantially at right angles to the first named passages and communicating with said central opening and thus with said conduit, and a mechanical atomizing nozzle sup ported within said shield in spaced concentrical relation and arranged to emit through said central aperture a substantially conical spray of oil, the interior of said hollow shield communicating with said central opening conduit to flow around the nozzle and be emitted from the central aperture in said shield, said hollow shield having radial openings" to interconnect the hollow interior of the shield and the second named air passages.

9. In an oil burner, an air conduit, a closure head mounted in the outlet end of said conduit and having a central axial opening therethrough central opening, a shield having a hollow cylindrical portion with diametrically opposed notches in its outer periphery mounted in said central opening so that the passages afforded by said notches between the shield and the wall of said central opening are disposed at right angles to the first named air passages, said shield having a partly conical front wall with a central aperture therein, and a mechanical atomizing nozzle mountedwithin said hollow cylindrical por tion in spaced concentrical relation therewith and. with its tip spaced back from said conical wall to allow air to flow between it and said wall,

said nozzle arranged to emit through said aperture a conical spray of oil.

10. In an oil burner, a tubular conduit for supplying air, an atomizing nozzle located substantially centrally at the outlet end of said conduit for producing a substantially conical spray of oil, an air head at the outlet end of said conduit having upper and lower front walls converging toward one another in a forward direction and terminating in a substantially rectangular discharge mouth with long upper and lower edges and relatively short side edges, bafile means at the right and left sides of said nozzle for intercepting the straight flow of air through said discharge mouth adjacent the sides of said nozzle, said batlle means cooperating with the converging front walls of said head for directing streams of air, one from above and one from to permit air from said.

below said nozzle, in forwardly converging relation to impinge on said conical oil spray after it leaves said nozzle and tending to flatten the shape of the flame produced by said burner, said baflle means providing for the admission of two straight flow streams of air through said discharge mouth at positions spaced from thesides' of said nozzle, one stream at the right side and one at.the left side of said' nozzle.

11. In an oil burner a tubular conduit for supplying air, an atomizing nozzle located substantially centrally at the outlet end of said conduit for producing a substantially conical spray verging front walls of said head for directing I streams of air, one from above and one from below said nozzle, in forwardly converging relation to impinge on said it leaves said nozzle and tending to flatten the shape of theflame produced by said burnerQsaid baflie means providing for the admission of two conical oil spray after straight flow streams of air through said discharge mouth at positions spaced from the sides of said nozzle, one stream at the right side and one at the left side of said nozzle.

12. In an oil burner, a tubular conduit for supplying air, an atomizing nozzle located substantially centrally at the outlet end of said conduit for producing a substantially conical spray of oil, an air head at the outlet end of said conduit having upper and lower front walls converging toward one another in a forward direction and terminating in a substantially rectangular discharge mouth with long upper and lower edges and relatively short side edges, baflle means at the right and left sides of said nozzle for intercepting the straight flow of air through said discharge mouth adjacent the sides of said nozzle, said baflle means cooperating with theconverging front walls of said head for directing streams of air, one from above and one from below said nozzle, in forwardly converging relation to impinge on said conical oil spray after it leaves said nozzle and tending to flatten the shape of the flame produced by said burner, said balilemeans including a forwardly projecting conical shield surrounding said nozzle and spaced therefrom to provide for the emission lar stream of air around all sides of said nozzle at the front end thereof.

13. In an oil burner, a tubular conduit for supplying air, an atomizing nozzle located substantially centrally at the outlet end of said conduit for producing a substantially conical spray of oil, an air head at the outlet end of said conduit having upper and lower front walls converging toward one another in a forward direction and terminating in a substantially rectangular discharge mouth with long upper and lower edges and relatively short side edges, baflle means at the right and left sides of said nozzle for intercepting the straight flow of air through said discharge mouth adjacent the sides of said nozzle, said balile means cooperating with the converging of, a relatively thin annu- 01 smaller volume than of air, one from above and from below said' nozzle, in inwardly converging relation to impinge the outside of said conical shield, one stream at the right side and one at the left side of said nozzle, said straight flow iateral'streams being said upper and lower converging streams. 1

14. man oil burner, an air conduit, a closure head mounted in the outlet end of said conduit and having 'a central axial opening therethrough and two diametrically oppomd air outlet passages therethrough disposed oneon each side 01' said central opening, a hollow shield having a central aperture and mounted in said central o and closing the same except for said aperture and two diametrically disposed air passages between the shield and said head. which last named passages communicate ing and thus with said conduit, and a mechanical atomizing nomle mounted within said hollow aperture a spray of oil. 15. In an oil burner, an air conduit, a closur head mounted in the outlet end of said conduit and having a central spray after it leaves said noz- I flatten the shape of the flame with said central opena the interior of said hollow shield comand thus with said conduit, and a me-' I from saidconduit to flow around the male and i be emitted from the central aperture in said Shield.

'16. In an oil burner, an air conduit, a closure head mounted in the outlet end or said conduit and having a' central axial opening therethrough and two diametrically and closing thesame except for said aperture and two diametrically disposed all; passages between opposed air outlet passages vtherethrough disposed one on each side of said central opening, a hollow shield having a central aperture and mounted in said central opening the shield and said head, which last named pasinterior or said hollow shield communicating with named air passages.

. LEOLYN F. BPEAR.

aperturein said shield, said hol-