US 3092332 A
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United States Patent 3,092,332 ATOMIZING FUEL BURNER CONSTRUCTION Herman H. Bickel and William Lelgemann, Saginaw, Mich., assignors to The Wickes Corporation, Saginaw, Mich., a corporation of Michigan Filed Apr. 4, 1958, Ser. No. 726,529 4 Claims. (Cl. 239-405) This invention relates to an atomizing fuel burner construction and more particularly to a burner nonle and fuel line assembly for use in conjunction with a fluid medium under pressure for atomizing and discharging liquid fuel and which is so constructed as to disperse substantially uniformly any condensate which may result from cooling or expansion of the atomizing medium.
Apparatus constructed in accordance with the invention is particularly suitable for use in a multi-port atomizing nozzle of the kind used in conjunction with oil burners and similar devices and in which steam is the atomizing medium. In many oil burner installations it is de sirable to heat the fuel oil prior to its atomization, but such pre-heating sometimes is impossible or limited because of the flash point of a particular oil being lower than the necessary atomizing temperature of the oil. In other installations, however, the viscosities of the oils are such that preheating is neither required nor desirable. In such situations, the temperature of the oil will be considerably lower than the temperature of the atomizing steam. Consequently, close association of the oil and steam will cool the steam and cause condensation. In installations where the fuel oil and the atomizing steam are delivered to a horizontally positioned nozzle in separate, concentric tubes the fuel line may cool the steam to such an extent that condensate will collect in the steam line and flow to the lower part of the atomizing nozzle where it is discharged througth the lower nozzle orifices only. As a result, the lower nozzle orifices are unable to atomize the fuel oil properly. These lower nozzles, therefore, discharge oil and water in an imperfectly atomized state which allows oil to drop by gravity to the furnace floor. The lighter fractions of the oil then will evaporate and burn, but the residue remains in the form of carbon and necessitates periodic cleaning. Furthermore, the large volume of water issued from the lower ports evaporates from furnace heat and prevents atomized oil in this area from burning properly.
An object of this invention is to provide an atomizing nozzle construction for fuel oil burners and the like in which the atomizing medium is caused to swirl about the periphery of the fluid delivery tube so as to entrain condensate and distribute the latter substantially uniformly through all of the nozzle ports.
Another object of the invention is to provide an atomizing fuel oil burner construction in which atomized fuel is discharged substantially uniformly through all of the nozzle ports so as to provide a fuel spray of maximum efiiciency. Other objects and advantages of the invention will be pointed out specifically or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings, in which:
FIGURE 1 is a fragmentary view partly in side elevation and partly in section of apparatus constructed in accordance with the invention, the section through the nozzle end of the apparatus being taken on the line 11 of FIGURE 2;
FIGURE 2 is an enlarged, end elevational view of the nozzle end of the apparatus;
FIG. 3 is a side elevational view of a condensate disperser unit forming a part of the invention; and
FIGURE 4 is an end elevation of the disperser unit.
3,092,332 Patented June 4, 1963 Apparatus constructed in accordance with the invention comprises an outer pipe or casing 10 having a centrally bored fluid or steam passage 11, the rear portion of the passage 11 being of reduced diameter as at 12 and threaded at its outer end for reception of a correspondingly threaded T-fitting 14. The T fitting may be connected to a pressure gauge and a thermometer (not shown) in a conventional manner.
The reduced diameter portion 12 of the passage 11 communicates with a passageway 15 which is threaded at its outer end to receive the correspondingly threaded end of a fuel delivery pipe 17. The forward end of the reduced diameter portion 12 of the passage 11 also is threaded to receive the correspondingly threaded end of a fuel delivery tube 18 which is concentrically positioned within the passage 11. The diameter of the fuel delivery tube 13 is substantially less than the diameter of the bore forming the passage 11 so as to enable an atomizing medium such as seen to pass from near the rear end of the casing 10 to its forward end and completely surround the pipe 18. The atomizing steam may be introduced to the passage 11 through a pipe 20 having one of its ends threadedly received in a passageway 21 communicating with the passage 11 and having its other end connected in any conventional manner to a suitable source of steam under pressure.
The fuel tube 18 projects beyond the forward end of the outer casing 10, as is shown in FIGURE 1, the forward end of the outer casing 10 being exteriorly threaded as at 22 and on which is received a correspondingly threaded nozzle member 23.
The nozzle member 23 comprises an outer annular flange 24 of such size as to receive the threaded portion 22 of the outer casing 10 and is provided with a central bore 25 of such size as slideably to receive the forward end of the fuel tube 18. The bore 25 is provided with an annular groove 25 in which is received an O-ring seal 27 that engages the forward end of the fuel delivery tube 18. The bore 25 communicates with a substantially centrally located, cylindrical fuel chamber 28 which, at its peripheral edge, communicates with a reduced, rearwardly diverging, annular chamber portion 29 which extends adjacent to the periphery of the nozzle 23.
Extending from the rear face of the nozzle and diverging in a forward direction are a plurality of uniformly spaced, substantially cylindrical ports 30 which communicate with the annular chamber portion 29 in termediate the marginal edges of the latter. The angle of divergence of the ports 30 is so selected that each of the ports 30 intersects the chamber portion 29 at substantially a right angle. In line with each of the ports 30 is a mixing port 31 which extends from the annular chamber 29 to the outer face of the nozzle, each of the mixing ports 31 being coaxial with, but of larger diameter than, its associated port 39. Between each of the ports 31, the outer face of the nozzle is provided with grooves 32 to form air passages leading from the outer periphery of the nozzle towards its center so as to enable sufficient air or oxygen to be delivered to the center of the nozzle face to prevent the creation of a vacuum and the production of carbon.
The apparatus described thus far is similar to the apparatus disclosed in co-pending application Serial No. 398,678, filed December 17, 1953, and operates in a similar manner. Apparatus formed in accordance with this invention, however, includes dispersal means located in the path of the atomizing medium for dispersing condensate substantially uniformly to each of the discharge ports of the nozzle.
In the disclosed embodiment of the invention, the dispersing means is designated generally by the reference a chamber 29.
character 33 and comprises a ring 34 joined integrally to a collar or barrel 35, the ring and the barrel being bored longitudinally as at 36 so as'snugly to receive the fuel line 18: The perip hery of the disperser ring 34 fits closely to the inner wall of the steam passage 11 and is provided with a plurality of spiral grooves 37, preferably six in number, each of which preferably is located at an angle of substantially 45 to the longitudinal axis of the disperser 33. The construction and arrangement of the disperser ring 34 areflsuch that all steam discharged through the nozzle 23 must pass through the spiral grooves 37. As a result, the steam which reaches the ports 30 will be swirling circumferentially of the tube 10.
For the most efiicient use to be made of the swirling steam, the distance from the ring 34 to the ports 30 should be such as to form a swirl chamber 38 having a length about twice the thickness of the ring. The length of the swirl chamber may be rigidly controlled by manufacturing the collar 35 exactly twice as longas the thickness 'of the ring 34 and by so locating the disperser 33 Within the passage 11 that the forward end of the'colla'r 35 will abut the rear face of the nozzle 23. The disperser 33 may be maintained in the desired position by means of screws 39, one of which is shown in FIGURE 1.
T condition'the apparatus for use, the disperser 33 is positioned within the fluid passage 11 and the nozzle 23 screwed onto the casing 10. As the nozzle is screwed onto the steam tube 10, the fuel delivery tube will slide into the nozzle so as to be able to deliver fuel directly into the fuel chamber 28. Valves (not shown) may be opened to admit oil to the fuel delivery tube 18 and steam to the steam passage 11. Oil introduced to the delivery tube 18 will pass from the tube into the fuel chamber 28 and thence will pass into the annular mixing Inasmuch as the annular mixing chamber is of smaller cross-sectional area than is the fuel chamber 28,110 difliculty will be experienced in maintaining the mixing chamber full of fuel, even if the latter is introduced-under relatively low pressure. Steam introduced to the steam passage 11 will be forced forwardly and will pass through the spiral grooves 37 into the swirl chamber 38. As the steam swirls at high velocity through the swirl chamber, itwill entrain condensate in the chamber 38' and will disperse it uniformly to all of the ports 30.
a In order to permit the rear ends of the ports 30 to be located as close as possible to the longitudinal axis of the pipe 10, the forward end of the disperser is chamfered as at 40.
Steam introduced to the ports 30 passes through the mixing chamber 2? into the ports 31, carrying with it fuel from the mixing chamber 29. Inasmuch as the ports 30 and 31 communicate with; themixing chamber 29 intermediate the ends of the latter,- fuel will be drawn into the ports 31 around the entire periphery of the steam jet;
Because of the construction and location of the disperser unit with'relationto the nozzle ports, condensate having a tendency to collect in the swirl chamber is dispersed to each of the nozzle ports rather than being discharged through the lower ports. As a result, moisture in any of the nozzle ports is insuflicient to prevent proper vaporization of the fuel. Consequently, the nozzle is able to discharge substantially uniform amounts of vaporized fuel from each of its ports to create a fog-like mist which is readily combustible.
The disclosed embodiment is representative of a presently preferred form of the invention, but is intended to be illustrative rather than definitive thereof. The invention is defined in the claims.
1. In an atomizing fuel burner construction, a generally horizontally disposed nozzle member having a rear end and a forward end and including a plurality of individual, restricted diameter atomizing fluid ports spaced circumferentially' around said nozzle member and extending therethrough from the rear end to the forward end, said nozzle member also having a transversely extending fuel chamber therein intersected by each of said ports; a fuel delivery tube connected to said nozzle member and extending through the rear end of said nozzle member axially inwardly of the rear ends of said ports to communicate with said fuel chamber for supplying the latter with fuel; an atomizing fluid delivery' tube of greater diameter than said fuel delivery tube and spaced diametrically therefrom substantially concentrically receiving said fuel delivery tube and defining a chamber of relatively large volume therearound connected to said nozzle member and directly communicating with each of said ports for supplying the latter with atomizing fluid under pressure; and a swirling ring closing said chamber and having spaced, narrow, generally axially angular groves which speed the flow of the atomizing fluid forwardly and start it whirling, said ring being spaced rearwardly of the rear of said nozzle member and rear ends of said ports a predetermined distance to define a swirler chamber of substantial axial length between said-ring and rear ends of said ports through the nozzle member surrounding the fuel delivery tube in which the whirling atomizing fluid can, with predetermined velocity in a predetermined space, pick up condensate condensing in said swirler chamber rearward of said ports, and entrain said condensate in said atomizing fluid todisperse it uniformly to each of said ports through which said atomizing fluid proceeds substantially in'an axial path without whirling. V
2. The combination defined in claim 1 in which said ring has an integral sleeve extending to and spacing it from the rear end of said nozzle member so that it will not be replaced backward upon removal.
3. The combination defined in claim 1 in which said burner ports angle outwardly relative to the axis of the nozzle and are of greater diameter from said fuel chamber to the front of said nozzle member than from the rear of said nozzle member to the fuel chamber.
4. The combination defined in claim 1 in which the grooves in said ring are circumferentially relatively wide- '1y spaced apart relative to their width.
Referen'cesCited' in the file of this patent UNITED STATES PATENTS 433,639 Arnold Aug. 5, 1890 716,724 Lasso'e et a1 Dec. 23, 1902 758,206 Grundell et a1 Apr. 26, 1904 1,586,006 Rochefort May 25, 1926 2,678,236 Tinker May 11, 1954