FLAME RETENTION BURNER HEAD
The present invention relates to a burner head for oil burners and particularly to an improved flame-retaining type of burner head adapted to effect improved 5 combustion of fuel.
In the type of burner with which the present invention is concerned, oil under pressure passes thru an atomizing nozzle, a stream of air being forced against the oil particles or droplets to form an intimate, com- 10 bustible mixture.
Such equipment desirably is designed to provide for the intermixture of the air and the oil particles in such a way that the combustion zone is maintained in the burner head instead of being blown out so that a self- 15 sustaining and controlled combustion reaction takes place.
Combustion is effected in a burner head comprising an elongated casing or tube which conducts a continuous stream of air blown therethru from the rear by a 20 suitable air pump or blower. The conventional burner head or casing contains an atomizing nozzle carried on an internal axially extending oil supply pipe which is supplied with oil under pressure. Ignition means, usually carried by the pipe, comprises suitable elec- 25 trades extending into the combustion area just beyond the atomizing nozzle in the combustion area.
The flame retention baffle is arranged transversely of the air stream, occupying a substantially annular section coaxially of the burner tube just beyond the 30 atomizing nozzle. A central aperture in the baffle admits and accommodates the spray discharge cone from the nozzle. The outer periphery of the annular baffle being spaced a substantial distance from the inner wall of the tube allows for a large flow of air thereabout. 35 Also the baffle is frusto conical in shape, its base being open and facing in a downstream direction. This, of course, tends to facilitate air flow without excessive upstream turbulence.
The present invention contemplates a flame retention baffle, comprising a transverse annular plate combined with a marginal annular ring which extends in an axial direction with respect to the burner tube, said ring making an obtuse angle with the transverse plate. As a result, the eddies set up by the transverse plate are elongated and retained more effectively and can be controllably supplied with air as will hereinafter be more fully described.
Referring now to the drawing wherein a preferred embodiment of the present invention is described in greater detail,
FIG. 1 represents a vertical, longitudinal section thru a burner head constructed in accordance with the present invention. ^
FIG. 2 is an elevational view of said burner head taken, as viewed from the right in FIG. 1.
FIGS. 3 to 6 are more or less diagrammatic fragmentary representations showing the action of the elements within the burner head upon air and fuel streams and 6Q upon flame conformation; FIGS. 3 to 5 being more or less fragmentary sectional elevations taken diametrically thru the head and FIG. 6 being the end or transverse view illustrating the transverse pattern of the flame, taken on the line 6—6 of FIG. 5. 65
FIGS. 7, 8,9 and 10 show end and side elevations of two modified flame retention baffles constructed in accordance with the present invention.
In the drawings the burner head comprises a cylindrical tube 10 associated with conventional blower, oil pump, controls and supporting mechanism (not shown), which provide a substantial oil supply pipe 12, mounted centrally and axially of the tube 10 and bearing on the extremity thereof of an atomizing nozzle 14. Also extending into the tube and mounted on the pipe 12 by means of support 16 are ignition members 18 terminating in a pair of electrodes 20 which, in turn, extend just ahead of the atomizing nozzle in the path of the spray. A predetermined, substantial flow of air under pressure is passed thru the burner tube 10 in the direction of arrows 22, by a conventional blower, not disclosed, and out past the nozzle 14 and thru the outlet of the burner tube.
The present invention specifically involves a flame retention head including a transverse plate 24 and an axially extending annular ring 26 in a frusto conical configuration in order to minimize undesired turbulence in the main air stream thru the burner tube. The term "transverse" as used herein is intended to include some relatively moderate degree of frusto conical arrangement, for example, less than 45° with respect to the radius of the tube. The ring 26 extends at somewhat of an obtuse angle with respect to the transverse plate 24 (as measured in an axial-radial plane). Thus the term "axially extending" as used herein with respect to the ring 26 is meant approximately parallel to the axis of the tube and with a divergence therefrom less than 45° outwardly with respect thereof.
The flame retention baffle formed by the plate 24 and the ring 26 is shown coaxially of the burner tube 10, occupying an annular coaxial portion of the cross section thereof, the central portion being open to receive the spray from the atomizing nozzle 14 and the outer periphery being spaced substantially inwardly from tube 10 to permit a substantial peripheral flow of air.
The peripheral stream of air is controlled by means of a choke plate 28 which adjusts the stream for purposes to be hereinafter described.
Thus control of the peripheral flow of air also enables inward flow direction of a portion of the air stream by means of louvers 30 and 32.
Entirely apart from the flame controlling the function of which is to be described later in greater detail, the present invention provides a practical and useful mechanical structure for mounting, erecting and supporting the entire flame retention head or assembly. This is accomplished by struts 34 mounted on or welded to collar 36 which embraces the spray nozzle 14 and may be fixed thereto by set screw 38 or any other equivalent means. Struts 34 extend axially into contact with the margin of the transverse plate 24 to which they are welded. From this point they extend radially outwardly as at 40 to support the choke plate 28.
Support of the choke plate is effected by machine screws 42 and spacing tubes or collars 44. The collars 44 thus space the choke plate 28 from the supporting struts 40 a predetermined distance and are held in place by the machine screw 42 and washer and nut 46. Optionally, the strut component itself may be threaded, eliminating the nut component 46. As a result, therefore, the entire internal assembly may be inserted from the rear of the burner tube in a conventional manner after appropriately adjusting the choke plate spacing