US2680652A - Atomizer - Google Patents

Description

L. KOOISTRA June 8, 1954 ATOMIZER 2 Sheets-Sheet 1 Original Filed Feb. 15, 1946 FIG.4

INVENTOR LAMBERT KOQISTRA W ATTORNEY L. KOOISTRA June 8, 1954 ATOMIZER 2 Sheets-Sheet 2 Original Filed Feb. 15, 1946 FIG.7

FIG.5

INVENTOR LAMBERT KOOISTRA ATTORNEY Patented June 8, 1954 AT OMIZER Lambert Koolstra, Akron, Babcock & Wilcox Com Ohio, asslgnor to The pany, New York, N. Y.,

a corporation of New Jersey Original application February 15, 1946, Serial No.

647,745, now Patent No.

1950, Serial No. 165,950

2 Claims. 1

The present invention relates in general to atomizers and more particularly to mechanical atomizers adapted for operation with liquid fuels of widely different characteristics and especially applicable to fuel burning installations requiring a high degree of heat liberation per unit of fuel cost. A wide range of liquid fuels may be effectively employed, varying from high volatile low flash point gasolines to low volatile high flash point fuel oils, such as kerosenes or diesel fuels.

The present application is a division of my prior copending application Serial No. 647,745, filed February 15, 1946, and issued as Patent No. 2,510,118, June 6, 1950.

The atomizers of this invention are of simple, low cost construction, involving a minimum number of prefabricated parts. Each atomizer, or nozzle, also embodies a means for preventing escape or dribble of liquid fuel from its discharge orifice, due to residual pressure, for example, after the supply of fuel has been shut off in the exterior fuel supply line. For installations requiring a plurality of atomizers, a group of atomizers may be embodied in a single burner wherein all atomizers of the group are in communication with a common internal fuel supply chamber to further reduce the overall cost of fuel burning equipment.

The various features of novelty which characterize my invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better under standing of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of my invention.

Of the drawings:

Fig. l is a side view, mainly in section, of a multi-nozzle burner assembly constructed in accordance with my invention;

Fig. 2 is a. plan view of the burner shown in Fig. 1;

Figs. 3 and 4 are sectional views of Fig. 1, taken along lines 3 3 and 4-4, respectively;

Fig. 5 illustrates part of a fuel conduit system serving burners of the type detailed in Figs. 1 to 4;

Fig. 6 is a modified form of atomizer or nozzle; and

F 7 is a sectional view of Fig. 6, taken along line 1--'!.

In more detail, and referring to Figs. 1-5 in particular, the burner i0 comprises an assembly 2,510,118, dated June Divided and this application June 3,

of three atomizers or atomizing nozzles l2, l2, and [4, of a mechanical pressure atomizing type, arranged in angular relationship as shown, and having axial discharge orifices 15 in a common plane, with each outer nozzle diverging from the central nozzle l2 at approximately 45. The nozzles are assembled in a flat sided burner body or block it suitably formed from plate stock and machined to provide intersecting bores ll in which the respective nozzles are secured by means of threaded connections Hi, the inner ends of the bores ll combining to provide an internal fuel inlet chamber I 9 common to all nozzles. A fuel inlet pipe 2|, opening into the chamber [0, is connected to the base of the burner block by means of weld metal 23. The internal machining operations are therefore limited to the formation of threaded bores l I and the fuel inlet opening to chamber [0.

As shown in Fig. 1, the burner It] has associated therewith an electrically energized fuel igniter element 25 having a portion wound into a helical coil 25 of relatively small diameter and sup ported in operative relation to the burner 10 by means of a bracket 21; the ignitor assembly being disclosed in more detail in the aforesaid copending application. Duplicate nozzles I 2, 12 are installed in positions remote from the ignitor while the third nozzle M, which provides a difierent character of spray in starting up, as later described, is installed in a position adjacent the ignitor. In similar burners l0, when the principal consideration is to provide equal sprays at normal operating capacities, either form of nozzle 12 or M may be used throughout.

Suitably, burners H] are installed in a fuel conduit system of the arrangement shown in Fig. 5 wherein the fuel inlet pipes 2| of successive burners I!) are connected to successive portions 28 and 29 of a burner supply line 30 to which fuel is delivered from a feed main 3! through a feeder conduit 32, the fuel being supplied under pressure to the feed main, and thus to the systerm, by means of a pumping apparatus, for example, such as disclosed in the aforesaid parent application. In accordance with the prior disclosure, it will be understood that the burner line portion 28 may be disposed at a lower elevation than the portion 29; that the feeder connection 32 is thus made to the lowermost portion of burner line 30; and that burners l0 and the associated burner inlet pipes 2| may be arranged so as to drain back into the line 30.

A drain line 34 is provided through which the fuel distributing system may be placed under 3 suction, and fuel withdrawn therefrom, if desired, the drain line being suitably installed at or below the level of the various fuel supply lines, and having a connection to a drain pump unit, for example, as disclosed in the parent application.

The feeder line or conduit 32 is provided with a plug valve 35 therein for controlling the supply of fuel to burners connected to burner line 30; the feeder conduit having a drain connection '36 from the outlet side of valve 35 to the drain line 34; and the connection 36 having aplug valve i! therein operable in unison with the plug valve 35 as indicated in Fig. 5. The valve control mechanism comprises an operating lever 38 mounted on the stem of fuel supply valve 35 and provided with handles 39 at opposite ends, a similar lever 38a being mounted on the stem of the corresponding drain valve 31 and pivotally connected tothe operating lever 38 of valve 35 by link bars lil. A valved vent connection, not shown, may be provided in burner line 30 at the highest point therein, in order to permit withdrawal of oil from the line if desired.

The burners iii are of a mechanical pressure atomizing type adapted to operate at especially high pressures to provide a highdcgree of atomization and a high rate of heat liberation using various low grade hydrocarbon oils. Further more, the construction of the burners is such that the total outlet therefrom is automatically sealed against air intake when the oil supply pressure is cut off and the burner line placed under suction.

Each nozzle l2 includes a body portion ill having its inner end externally threaded to form the connection it with the burner block IE, a central bore A2 in part 41 terminating in an enlarged outer end cylindrical recess or counterbore t3, and the rim of bore 42 at its intersection with the base of recess 13 being beveled as at 45 to provide a circular seat for a stainless steel ball 2E. A sprayer plate Al, having a Whirl chamber 48 therein terminating in the orifice i5, is formed with a planar base surface in which are formed four tangentially arranged slots #9, closed at their outer ends, for directing oil into the whirl chamber 58, the slots 49 entering the chamber through a cylindrically walled portion 5| at the base of the chamber, substantially as, shown in Fig. 3. The sprayer plate 4'! is held in assembled sealed relation against the planar outer end of nozzle body ll by means of a flat-sided cap 52 having a threaded connection 53 therewith. The number of slots .9 may be increased or decreased to meet operating requirements.

When a nozzle i2 is in operation the pressure of oil supplied thereto forces ball 45 from its seat 55 into contact with the circular rim or edge 54 of whirl chamber 48, a position indicated in Fig. 1 by the dotted circular outline, thus closing off entrance to the whirl chamber except through the inner ends of sprayer plate slots 49, and thereby causing the oil to enter the whirl chamber in substantially tangentially directed streams. In starting up, while balltfi is being lifted toward its seat against rim 54, the oil enters the whirl chamber longitudinally instead of tangentially and thus for a brief period is discharged from orifice E5 in a relatively solid stream. The form of discharge changes quickly however to the normal angularity of spray cone at full capacity discharge. When the oil supply pressure to burner 19 is out off and the burner placed under suction, ball 46 is pulled inwardly, against seat 45 to maintain a seal against intake of air.

Nozzle I4 herein shown adjacent ignitor coil 26 includes a nozzle body 56 formed with a central cylindrical closed-end fuel passage 51 having its inlet end portion 58 of enlarged diameter to receive and hold a bushing or sleeve 59 therein, the bushing providing a beveled circular seat 6| for ball 48 at the inner end of the central bushing passage 62, the seat 6i being spaced a sufficient distance from the conical end surface 68 of passage 51 to permit the required longitudinal movement of ball 36 therebetween. Circumferentially spaced fuel conducting ports 64 extend from an inner end portion of passage Ell to an annular groove or recess 65 in the outer end surface of nozzle body 55. A sprayer plate 41 and cap 52 complete the nozzle assembly.

In this form of nozzle 14, when ball 46 is lifted from its seat 6| by oil supplied to the nozzle, the oil is released into the inner end of passage 51 from which it is conducted through ports 64 to the annular recess 55 and thence to sprayer plate slots 49, the ball 35 being forced against the conical surface 53 Where it remains centered with respect to the concentrically arranged ports 5 while oil is flowing. The ball thus merely acts as a valve and has no elfect on the character of spray discharged from orifice it. With this type of nozzle, when a burner ill is started up, as by opening the fuel valve 35, there is an interval during which fuel pressure at nozzle it must build up to normal, with the result that the initial discharge is a conical spray of larger included angle than when the internal fuel pressure has reached its highnormal value and the burner is operating at full capacity. Advantage is taken of this characteristic of operation by positioning the ignitor element 25 so that its effective heating portion 2% is contacted by oil from the initial wide angle low capacity spray 5'? upon starting up, but is out of the path of the narrower angle high capacity spray 58 during normal operation. Spray 63 from nozzle H3 is of substantially the same form as the spray produced by nozzle 12 at corresponding capacities.

lgniticn of the sprays from the three nozzles i2, i2, and it, is progressive, beginning with the spray from nozzle Hi nearest the ignitor element 2%, the flame starting at a substantial distance from the tip of nozzle i4 and thus the exposed portion of ignitor 25 is located in a relatively cool zone, under the cold liquid spray cone, where it is shielded from intense flame radiation; in this position also, the ignitor being disposed in a current of air'induced by the high velocity oil discharge, which helps to keep the element from becoming overheated should the power he left on during burner operation.

When the system shown in Fig. 5 is to'be closed down, it is assumed that the associated suction pump apparatus, or other equivalent means, is in operation to exert a suction on suction line 3 Valve 35 is then moved to its closed position to out off oil supply to burner line 39 whereupon valve 37 is automatically opened to place burner line 30 under suction. The suction pressure assumed to be of the order of 10 p. s. i. is trans mitted to all nozzles l2 and M where it immediately acts to pull the balls 46 inward against their respective seats to seal the nozzles against intake of air.

The dribble or escape of oil from the nozzles after shut-down is thus prevented, whether due to residual pressure or more particularly to differences in nozzle elevations, a distinct advantage of the system being that no oil need be withdrawn from the system, thereby economizing in the power required for pumping. A further advantage is that the system is maintained in complete readiness for instant starting, with oil at the nozzles, the moment the oil pressure supply is again opened up. Provision may be made however for draining the system, if desired, by installing valved vent connections as previously mentioned which when opened allow air to enter the system to permit withdrawal of oil.

Fig. 6 illustrates a modified form of atomizer or nozzle H suitable for use in the system described, and in fuel burning systems generally,

for preventing the dribble or continued escape of oil after the fuel supply valve 35, for example, has been closed. Nozzle ll produces a pattern of spray substantially equivalent to the spray produced by nozzle 14 and accordingly is interchangeable therewith. Nozzle I! may be installed in any position, with or without association with an ignitor, and therefore is also interchangeable with nozzle l2. As shown in Fig. 6, the nozzle H is formed with a body portion 72 which is screwed into one end of a coupling 73 having its other end connected to a fuel inlet pipe 2|. Being interchangeable with other nozzles, one or more nozzles H may be assembled in a burner block [6, for example.

The nozzle body 12 is formed with a central circular fuel passage 1'4 extending therethrough, the outlet end of passage 14 being enlarged as at 75 to form an intermediate shoulder portion providing the beveled circular seat 18 for ball 46.

A sprayer plate 47 is assembled at the outer end of passage 15 where it is clamped against the outer end of body '12 by means of cap 52. A second ball 18 is positioned adjacent the sprayer plate 47 where it is maintained in contact with rim 54 at the base of whirl chamber 48 by biasing means in the form of spring 19 which urges balls 46 and 78 in opposite directions. Spring 19 is desirably of rectangular formation transversely of its length as shown in Fig. 7 so as to provide corner portions 8| substantially in contact with the circular inner wall of passage 15 and thereby maintain axial spring alignment with minimum resistance to axial movement during operation.

In the operation of burner nozzle "ll, the inner ball 46 acts as a valve to prevent fuel flowing into the whirl chamber 98 until the fuel pressure has built up sufficiently to overcome the opposing force exerted by spring 19. Since the outer ball 18 is maintained continuously in contact with the rim of whirl chamber 48, the pattern of spray in starting up, and at normal capacity operation, is therefore the same as produced by nozzle l4. Nozzle H has the advantage however of a simpler, less expensive construction, requiring fewer machining operations. Nozzle H has the further advantage that the burner line 38 is closed and sealed off from the atmosphere as soon as the pressure in the line has decreased below a predetermined point at which the inner ball 46 becomes seated. In a system using nozzles H throughout, it is therefore not necessary to keep the system under suction when not in operation. Moreover, the system is maintained in a condition for instant starting, with oil at the nozzles,

the moment the oil pressure supply is reopened. substantially as described in connection with nozzles l2, and I4.

As disclosed in the parent application, each of the nozzles l2, l4, and H is adapted for use with a wide range of liquid fuels, and is especially useful when a high degree of fuel atomization is to be effected. In general, for a given sprayer plate and output capacity, higher atomizing pressures are required for adequate atomization of fuels of heavier grades, and lower atomizing pressures for fuels of lighter grades. For high quality atomization, therefore, using a diesel fuel, for example, with a suitably proportioned sprayer plate, atomizing pressures ranging upwardly to 1500 p. s. i. may be advantageously employed, for an available output of 1100 lbs. of oil per hour per nozzle. correspondingly lower pressures may be employed for fuels of lighter grades, particularly under conditions when a lower degree of atomization will suffice.

While in accordance with the provisions of the statutes I have illustrated and described herein the best form of my invention now known to me, those skilled in the art will understand that changes may be made in the form of the apparatus disclosed without departing from the spirit of the invention covered by my claims, and that certain features of my invention may sometimes be used to advantage without a corresponding use of other features.

I claim:

1. A mechanical atomizing liquid fuel nozzle comprising a body member having a liquid fuel passage therein, said passage opening into an enlarged outer chamber within said member and having a circular valve seat at the inner end of said outer chamber, a sprayer plate having a whirl chamber therein of circular cross-section open at its bottom inner end and having a discharge orifice at its opposite outer end, a slot in the bottom of said sprayer plate opening substantially tangentially into said whirl chamber, outer and inner ball valves in said outer chamber arranged to close the bottom of said whirl chamher and to seat on said circular seat respectively, and biasing means in said outer chamber arranged to resiliently separate said ball valves.

2. A mechanical atomizing liquid fuel nozzle as claimed in claim 1 wherein said biasing means comprises a coiled spring of polygonal formation transversely of its length so as to present corner portions toward the wall of said chamber.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 423,157 Hubbard Mar. 11, 1890 598,893 Joy Feb. 8, 1898 1,250,600 Light Dec. 18, 1917 2,098,487 Cooper Nov. 9, 1937 2,243,995 Alden June 3, 1941 2,378,438 Wilmer June 12, 1945 2,399,182 Gustafsson Apr. 30, 1946 FOREIGN PATENTS Number Country Date 571,686 France Feb. 7, 1924 573,212 Germany Mar. 30, 1933

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