US2042034A - Oil burner - Google Patents

Description

y 1936- D. E. WYMAN 2,042,634

OIL BURNER Filed Feb 16, 1 954 5 Sheets-Sheet 1 INVENTOR:

. Y- 1936' D. E. WYMAN 2,042,034

WITNESSES: I N VEN TOR:

ATTORNEYS.-

Patented May 26, 1936 UNETED STATES PATENT OFFIQE OIL BURNER Philadelphia, Pa., a vania corporation of Pennsyl- Application February 16, 1934, Serial No. 711,499

9 Claims.

This invention relates to oil burners and atomizers of a type useful more particularly in connection with furnaces and boilers.

In the main, my invention is directed toward the provision of an oil burner which is simple in construction and operation; which can be relied upon to effectively atomize the oil and to intimately mix it with air to form a perfect combustible vapor mixture; which can be accurately regulated for efiicient atomization over a wide range of capacities with the various grades and kinds of oil wherewith it may be supplied; and which can be readily taken apart for convenience of inspection and. cleaning.

Other objects and attendant advantages will be manifest from the following detailed description of the accompanying drawings; wherein, Fig. I is a sectional view of my improved oil burner.

Fig. II is a rear elevation of the same.

Fig. III is a perspective View of the main or body member of the atomizing nozzle of the burner.

Fig. IV shows the front end elevation of an oil spreader head forming a part of the atomizing nozzle.

Figs. V and VI are views corresponding to Figs. I and II showing an alternative embodiment of my invention.

Fig. VII is a fragmentary view showing another modification.

Fig. VIII is a View, partly in elevation and partly in section, of still another embodiment of my invention.

Fig. IX is a fragmentary perspective view of an adjusting means associated with the burner delineated in Fig. VlII; and,

Fig. X is a fragmentary view showing a further modification of my invention.-

Referring first to Figs. I-IV of these illustrations, the embodiment of my novel burner therein depicted, comprises a hollow elbow-like housing l0 which is connected to a vertical pipe ll leading from a blower or other source of air under pressure, not shown. The flow of the air into the burner housing I0 is controllable by means of a butterfly valve l 2 which is secured to a transverse shaft l3 having rotative bearing in a conventional form of stuffing box M. This stuffing box l4 may be formed either at the side of the pendant extremity 15 of the burner housing I0; or it may be formed on a separate valve casing l6 secured to the burner housing It], as shown, by means of screw bolts 11. Tightening of the gland nut l8 of the stufiing box M will obviously compress the packing at the interior, to prevent air leakage around the shaft I 3, as well as impose a binding restraint upon the latter and thereby preclude accidental turning of the valve l2 after adjustment. For the sake of structural simplicity, the projecting end of the shaft I3 is in this instance bent at right angles, as at Hi, to serve as an actuating handle for the valve l2. The forward end of the horizontal cylindric portion 20 of the burner housing l0 terminates in a taper 2| with an axial outlet :orifice '22; while the rear end of said portion is closed by a removable cover plate 23 which is held in place by cap screws 24.

Axially within the forward end of the bore or chamber 25 in the horizontal portion 20 of the housing I0 is an atomizing nozzle 26 of corresponding shape but of smaller dimensions, with resultant formation of an annular passage 21 between said nozzle and the housing In. By way of this passage 21, some of the air is conducted from the chamber 25 of the burner housing In to the outlet orifice 22 and released around the spray of atomized oil concurrently discharged from the end of the nozzle tip as later on explained. In traversing the annular passage 21, the air encounters a number of circumferentially-arranged spiral vanes 28 whereby it is gyrated for release as a helical whirl through the orifice 22 along the horizontal axis of the burner housing H]. In this instance, the vanes 28 are integrally formed with the body 29 of the nozzle 26. However, if found desirable or expedient in practice, the vanes 28 may be formed in the burner housing I0, or they may be provided by a separate insert.

Axially of its forward portion, the body 29 of the nozzle 26 has a Venturi passage with a short constriction or throat 30 between a convergent inlet portion 3| and a divergent discharge portion 32; while at its cylindric rear end, said nozzle has an axial bore with a threaded part 34 and a smooth portion, which latter is in part cylindric as at 35, and in part tapered or conical as at 36. Engaging the threaded part 34 in the nozzle body 2.9 is a distributer head 31 having a removable conical tip 38 whereof the bore or converging hollow 39 is open axially into the inlet portion 3| of the Venturi passage in the nozzle body 29. The size of the tip 38, it will be noted, is such that there is formed, coaxially of the nozzle 26, a relatively narrow annular oil flow channel which is in part cylindric as at 4B and in part conical as at 4|, and which communicates laterally all around with the inlet end 3| of the Venturi passage at 42. Fuel oil is delivered. axially to the rear of the nozzle 26 through a pipe nipple 43 having threaded connection at 44 into the distributor head 31. From thence the oil is conducted, by way of a number of relatively small radiating ducts 45, to the cylindric portion 40 of the annular flow channel within the nozzle body 29. Alternating with the oil ducts 45 are larger ducts 46 whereby some of the air is conducted from the chamber in the burner housing It, to the convergent hollow 39 within the tip 38 for induction at increased velocity into the inlet portion 3| of the Venturi passage. The opposite end of the pipe nipple 43 is screwed into a sleeve-like extension 41 which has an exterior thread 48 engaged by a tubular nut 49. This tubular nut 49 is formed with a stop fiange 5|! to engage the inner side of the cover plate 23; and secured to the protruding end of the said tubular nut is a hand wheel 5| whereof the hub 52 abuts against the outer side of said cover plate. The tubular nut 49 is thus confined to rotation within the bearing aperture 53 provided for it in the cover plate 23. Turning of the hand wheel 5| will, as a consequence of the described construction, be attended by shifting of the nozzle 26 axially within the horizontal portion 29 of the burner housing l0, whereby the fiow capacity of that portion of the annular air passage 21 surrounding the tapered atomizing nozzle 26 is variable, with consequent increase or decrease in the amount of secondary mixing air released through the outlet orifice 22. In order to prevent rotation of the nozzle 26 incident to its adjustment as just explained, the cover plate 23 is provided with an inward guide stud projection 54 which freely engages an aperture or notch 55 in a flange 55 of the sleeve 41. The stud projection 54 may be integrally formed with the cover plate 23, or it may be in the form of a screw suitably anchored in the plate as shown in Fig. I.

The fuel oil is conducted to the burner from a supply source (not shown) through a vertical pipe 51 which has a short horizontal branch 58 connected to the outer end of the sleeve-like extension 41, a T fitting 59being used at the juncture of the branch with the supply pipe 51. As shown, the T fitting 59 is normally closed by a removable plug 59. Interposed in the pipe 57 are a needle valve 6| whereby the supply of oil to the nozzle 25 may be very accurately regulated; a strainer 62 with a removable screen 63; and a shut-off valve 64.

The operation of the burner is as follows: The oil entering the distributor head 3'! at the rear of the nozzle 26 is divided in passing through the ducts 45 on its way to the cylindric part 40 of the annular oil fiow channel. In traversing this cylindric part 40 and its convergent continuation 4| of the fiow channel, the oil is spread as a thin annular film enroute to the inlet portion 3| of the Venturi passage. The air axially discharged into the Venturi passage from the convergent hollow 39 in the tip 38 of the head 31, in passing through the throat 30, sets up a suction or partial vacuum whereby the oil is withdrawn as an annular film from the channel 40, 4| and given its primary atomization in the discharge or mixing portion 32 of said Venturi passage. As it leaves the nozzle 25, the fuel and air mixture meets the surrounding whirl of the spirally-rotating secondary mixing and vaporizing air issuing from the orifice 22. By the agitation set up through the whirling secondary air about the discharge of the primary mixture, a thorough and uniform final mixing results whereby the oil is broken up into a fine mist in the presence of an ample amount of combustion supporting air. Intimate mixing of the air and oil in the manner just explained, creates a very desirable condition in that it facilitates lighting of the burner in a cold furnace without excessive smoke or danger of a flare back. By rotating the hand wheel 5| to shift the nozzle 25, the amount of secondary mixing and vaporizing air released through the orifice 22 may be regulated to adjust the burner for different combustion capacities. This, it will be noted, is accomplished without reduction of air pressure as is the case with most oil burners in common use. By adjustment of the needle valve 5| and the butterfly valve i2, the burner can obviously be adapted to the burning of fuel oils of different qualities and grades. With very heavy oils which have a tendency to solidify when cold, a steam or high pressure air supply may be connected to the T 59 upon removal of the plug 50 to expel all of the oil from the burner when said burner is shut down to prevent such solidification.

When inspection or cleaning of the internal parts of the burner is necessary, said parts can be bodily withdrawn, as will be readily understood from Fig. I, by unscrewing the coupling at 65 in the oil pipe 57 and removing the cap screws 24 which hold the cover plate 23 in place. The provision of an air valve l2, as a unit separate from the burner, makes possible the complete shuttingoif of the air when the burner is to be taken apart as aforesaid.

In instances where, in order to accommodate the adjustments of the nozzle, fiexure of the oil pipe would be impracticable or undesirable, I resort to the construction shown in Figs. V and VI. In this case, the tube connection 43a into the rear end of the nozzle 25a is extended through the cover plate 23a and the hand wheel 5|a and its outer end slidably connected to the T 59a by means of a stufiing box 66, said fitting being rigidly held against movement through screw engagement at 6'! with a bracket 68 secured to the cover plate 230.. Furthermore, in this instance, the threaded sleeve 47a is permanently made fast to the oil flow tube 43a so that the latter is shifted axially incident to adjustment of the nozzle 26a by rotation of the hand wheel 5|a. In all other respects the construction of Figs..V and VI is identical with that of the first described embodiment of my invention, the same reference numerals having been used with an added exponent a to identify the corresponding parts and to dispense with the necessity for repetitive description.

In the modification shown in Fig. VII, the nozzle 25b is fixed in position within the housing Illb of the burner. Regulation of the flow of secondary mixing or vaporizing air through the orifice 22b is here effected by turning of the tapered end. or cap piece 2 lb, which, in this case, is made separate from the burner housing, and has screw engagement with the latter at 69.

Figs. VIII and IX show an alternative embodiment of my invention with provisions whereby the burner may be set or reset with absolute accuracy for maintenance of any prescribed condition of operation. As illustrated, the actuating handle |9c for the air valve |5c is made separate from the valve shaft I and formed with a pointer 10 for cooordination with graduations on a fixed arcuate scale 1|. The hand wheel Me for adjusting the nozzle of the burner of Fig. VIII is somewhat different in form from that associated with the embodiment of my invention shown in Fig. I, and provided with a thumb screw 12 to secure it to the sleeve 470 for assurance against accidental displacement after adjustment. The

smooth extended portion of the sleeve 41c projecting outward beyond :the hand wheel 5lc, it will be observed, has numbered circumferential graduations 13 corresponding to the pitch of the screw threads 480 as well as a longitudinal gradnation-"M along its top; while the end face of the hub 520 has numbered radial graduations 15. When the zero mark on the hub 52c registers with the longitudinal line 74 on the sleeve 410, the hub face will coincide with one of the circumferential graduations 13 on the sleeve 410, as shown, to indicate a definite setting of the burner nozzle. Registry, for example, of the mark I on the hub face of the wheel Bic with the line hi on the sleeve 410, will on the other hand indicate that the burner nozzle has been shifted from the illustrated position to an extent equal to exactly one-eighth of the pitch of the threads 430. Thus, with the arrangement just described, it is possible for an operator to accurately adjust the air valve I60 and the burner nozzle 26c for any operating condition according to prescribed rules, and to reset it for duplication of such condition upon reassembling of its parts after cleaning, or to duplicate any predetermined combination desired or required in meeting varying operating conditions.

In the modification shown in Fig. X, the oil tube 63d itself extends through the cover plate 23d and is guided for axial shifting movement in a boss 1'6 of said plate. The adjusting hand wheel 5Id, in this instance, is rotatable on the protruding end of the tube 43d and held in place between a pair of spaced collars l1 and I8 on said tube. As shown, the hollow inward portion 19 of the wheel hub 52d is internally threaded to engage with the screw threads 48d on the boss 76 of the cover plate 23d. The hub portion 19 of the adjusting hand wheel 5| is moreover formed with a circumferential flange 80 having a beveled face 8| which may he graduated like the face of the wheel hub 520 in Fig. IX. For coordination with the graduations on the fiange 80, I have provided a scale 82 which is secured to and projects rearward from the cover plate 23d. Turning of the hand wheel 5ld of Fig. X will obviously result in axial shifting of the oil tube 43d as well as the atomizing nozzle (not shown) attached to it within the burner housing Hid. In making the adjustments, the operator will be guided by coordination of the graduations on the flange 88 with those of the fixed scale 82 in a manner identical with that described in connection with the form of my invention illustrated in Figs. VIII and IX. After adjustment, the hand wheel 5ld is fixed against accidental turning by tightening the thumb screw 12d.

Having thus described my invention, I claim:

1. In a burner for liquid fuels, a hollow housing embodying a cylindric portion having one end tapering to provide an axial outlet orifice and at the other end a removable cover; an atomizer nozzle fitting the housing cylindric portion with provision of a surrounding secondary air-flow passage at its tapering end; said nozzle being provided with an axial Venturi passage in its forward part and with a rearward continuation including a communicating convergent, an intermediate cylindric, and outer screw-threaded sections respectively; a combined fuel-and-air distributor-head engaged in the threaded section and spaced from the other said sections to provide an intervening fuel-flow passage, said head having ducts connecting the fuel-flow passage with a common axial inlet at the rear of said head and intervening other ducts for conducting primary air to a forward axial-chamber in the distributor head; a conduit connecting the distributor-head to a source of fuel supply; and means whereby the atomizer nozzle is axially adjustable to vary the flow ofsecondary air to the burner outlet orifice.

2. In a burner for liquid fuels, a hollow elbowlike housing embodying a cylindric portion having one end convergently-tapered to provide an axial outlet orifice and at the other end a removable cover; an atomizer nozzle with circumferential spiral-vanes fitting the housing cylindric portion with provision of a surrounding annular passage'about the nozzle forward portion for whirling flow of secondary-air; said nozzle being provided with an axial Venturi passage having a comparatively short constriction, in its forward part and with a rearward continuation including a communicating convergent, an intermediate smooth-cylindric, and rear screw-threaded sections respectively; a combined fuel-and-air distributor-head engaged in the threaded section and correspondingly-shaped with respect to the smooth-cylindric and communicating convergent bore sections and spaced therefrom to provide a narrow intervening annular fuel-flow passage, said distributor-head having relatively small radiating ducts connecting the fuel-flow passage with a common axial inlet at the rear of the head with other comparatively-larger intervening ducts for flow of primary air under pressure to the communicating convergent bore section of the distributor-head opening into the Venturi passage inlet; a non-rotative conduit connecting the distributor-head through the housing cover to a source of fuel supply; means whereby the atomizer-nozzle is axially adjustable to vary the fiow of secondary air to the burner outlet orifice; and gauge means whereby the distributor-head may be adjusted and set for predetermined operating conditions.

3. The combination of claim 2 wherein the combined fuel-and-air distributor-head comprises a circumferentially screw-threaded main portion including a smooth cylindric extension and a removable conical tip having an axial convergent bore engaged thereon, said main portion having the relatively small radiating ducts intermediate the cylindric extension and a common axial inlet at the rear of the distributor-head,

and the intervening substantially-larger ducts in line with the taper of the tip convergent bore.

4. The combination of claim 2 wherein the non-rotative fuel supply conduit comprises a nipple having rigid connection with the distributor-head inlet at one end and an exteriorly screw-threaded sleeve-like extension into which said nipple is threaded at its other end, a tubular nut coactive with the screw-threaded extension and rotatively journaled in the burner removable cover, and means whereby said nut is rotatable and restrained against axial movement relative to said cover.

5. The combination of claim 2 wherein the non-rotative fuel supply conduit comprises a nipple having rigid connection with the distributor-head inlet at one end and an exteriorly screw-threaded sleeve-like extension into which said nipple is threaded at its other end, a tubular nut coactive with the screw-threaded extension and rotatively journaled in the burner removable cover, a hand wheel whereby said nut is rotatable and a stop flange on the latter to prevent its axial movement, and said cover is removable together with the nozzle and associated 'parts as a unit from the burner housing.

6. A distributor-head for spraying fluids embodying a circumferentially screw-threaded body portion with a plain cylindric diametrically-reduced section, a removable frusto-conical tip with an outwardly-convergent bore, said tip having a diametrically-reduced exteriorly-threaded portion engaged in a correspondingly-threaded bore in the plain cylindric section of the distributorhead, said distributor-head having a multiplicity of alternating fine and substantially-larger ducts through its body portion, the finer of which afiord flow passages intermediate a common inlet axially in the rear of said body portion and the meeting point of the plain cylindric and circumferentially screw-threaded sections thereof, and the larger ducts similar flow passages between circumferentially-spaced points exterior to the inlet aforesaid and the convergent bore in the distributor-headfrusto-conical tip.

7. The combination of claim 2 wherein the non-rotative conduit connecting the distributor head to a source of fuel supply has its outer end supported in a stuffing-box rigidly sustained by a stationary bracket projecting from the housing removable cover, whereby adjustments of the nozzle can be effected without flexing the supply connection.

8. A distributor-head for spraying fluids embodying a conical tip with an axial bore and a cylindrical body portion, said body portion having ducts connecting the exterior surface of the tip with a common axial inlet in the head rear end, and intervening other ducts connecting the rear of said head with the axial bore aforesaid.

9. A distributor-head for spraying fluids comprising a body portion including an attaching section with an axial inlet at its rear end, radiating ducts connecting said inlet with the head exterior surface beyond the attaching section, a removable conical tip at the forward end of the body portion having an outwardly converging bore, and other ducts through the body portion alternating with the radiating ducts aforesaid intermediate the tip converging bore and circumferentially spaced points in the rear of the distributor head.

DANIEL E. WYMAN.

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