US2631659A - Burner orifice spud - Google Patents

Description

March 17, 1953 wRlGHT 2,631,659

BURNER ORIFICE. SPUD Filed March 12, 1951 5, may/4O -1605 QGEA/T.

Patented Mar. 17?, 1953 BURNER ORIFICE SPUD James A. Wright, Webster Groves, Mo., assignor to Missouri Automatic Control Corporation, St. Louis, Mo., a corporation of Missouri I Application March 12, 1951, Serial No. 215,141

2 Claims.

This invention relates generally to gaseous fuel burners and more particularly to a fuel metering and diffusing device for use in connection with gaseous fuel pilot burners.

In the usual pilot burner of simple construction, having a fuel metering orifice, an air injecting means, and mixing conduit of fixed size, the characteristics of the flame at the burner port are afiected to a marked degree by variations in fuel velocity at the metering orifice. Inasmuch as commercial fuel supply pressures vary, thereby varying the velocities at the fuel metering orifice, it is desirable to provide means to compensate the effect of these variations so that the optimum flame characteristic may be more closely maintained over a range of fuel pressures.

.It has been found that in a burner of the above type, designed to operate eificiently at a par- The diffusion of the fuel and economical construction and adapted to convenient detachable assembly with a pilot burner.

A further object is to provide a unitary construction including a single thin plate fuel metering orifice and a fuel stream diffusing means in fixed relationship therewith, which device is adapted to convenient detachable assembly with a pilot burner.

Other objects and advantages will appear from the following complete description and accompanying drawing.

In the drawing,

Fig. 1 shows a pilot burner of conventional construction having assembled therein an orifice spud constructed in accordance with present invention;

Fig. 2 is an enlarged side view of the orifice spud shown in Fig. 1, having portions broken away to more clearly illustrate;

Fig. 3 is a left end view of the orifice spud shown in Fig. 2; and

Fig. 5 is an exploded sectional view of the orifice spud shown in Fig. 2.

The orifice spud consists of a body portion l which may be turned from a length of hexagonal stock. The body it has an externally threaded portion l I adapted to be threadably engaged in an internally threaded end portion of a pilot burner, and a rearward externally threaded portion 12 adapted to be threadedly en aged by a conventional conduit clamping nut I 3. Between the threaded portions II andglZ. the body is hexagonal. The body is further providedwith a bore M, :a rear end counterbore l'5 which receives the end of the fuel conduit IS, a forward counterbore I? which receives a thin orifice plate I8 and a washer-like spacer l9.

Rigidly attached to the spacer I9 is a diffusing.

bar 20. The diameters of the orifice plate l8 and the spacer l9 are. such as to nicely fit the counterbore H. The forward end of the body It is reduced in diameter as indicated at 2|, thereby leaving a thin wall 22 for the length of the counterbore H.

The orifice plate It and the spacer Hi, together with its attached diffusion bar 20, are assembled in the counterbore I1, and the thin wall 22 is then spun over at its outer end to hold these members in rigid assembly with the body member, as shown in Fig. 2 of the drawing. The diffusion bar 20 may be of any sectional configuration; presently, however, I prefer to use an inexpensive length of polished round wire of non-corrosive metal. The periphery and internal diameter of the washer-like spacer H! are con-centric, and the bar 20 extends across the exact center of the central perforation and is attached at its ends to the spacer by welding. The bar 20 is slightly shorter than the diameter of the spacer so as to permit the formed over wall 22 to lie against the face of the spacer at all points. The orifice plate It! has :an orifice lBa which is also concentric with the periphery of the orifice plate. It will be seen that with the above described arrangement,.an accurate and uniform relationship, both laterally and longitudinally, between the orifice 15a and the difiusion bar 20 may be readily maintained by the usual manufacturing methods.

The illustrated pilot burner has a lower elongated body member 23 having a through bore 24, and a lower end counterbore 25 which is internally threaded to receive the threaded portion H of the above described orifice spud. The

3 burner body member i also provided with :primary air openings 26, entering the chamber formed by the counterbore 25. Attached to the upper end of the body member 23 is a hollow elongated burner head '21 having burner ports 28.

In operation As fuel issues from the orifice 48a, it strikes the diffusion bar 28 and is, therefore, diverted, causing greater dispersion of the fuel in the air entering ports 26 and, therefore, causing a more thorough mixture of fuel and air entering and filling the passage 24 and the hollow burner 27 in which the fuel and air are further mixed. Without such diffusing means, the fuel stream passes through a greater portion of the passage 24 without filling the passage, in the sense that velocities are relatively extremely .high at the center of the fuel stream and extremely low near the Walls. As a result of this condition, the injected air blankets the fuel stream, and is, therefore, not sufficiently mixed. Also, as fuel velocities 'are increased without the diffusing means, this condition becomes more pronounced,

'andwhen a certain velocity is reached, a lifting of the flame at the burner port results.

With the provision of the above described diffusing means, however, a choking effect is achieved which not only improves the mixing of the fuel and air at all velocities, but also reduces mixture velocities and, therefore, permits the operation of the burner at higher fuel velocities without lifting of the 'fiame at the port.

The foregoing description is intended to be illustrative, not limiting, the scope of the invention being set forth in the appended claims.

I claim:

1..A fuel metering device for use in gaseous fuel "pilot burners, comprising a body member having a fuel passage therethrough, a counterbore at the outlet end of said fuel passage, and a circular orifice plate having a single concentric central metering orifice and being slidably received in said counterbore, a cylindrical spacer member having a concentric central passageway therethrough, being slidably fitted in said counterbore and overlying said orifice plate in face to face contact therewith at one end, a transverse difiusing bar Welded to the other end of said spacer and lying across the center thereof so as to bisect said metering orifice, and means for rigidly retaining said orifice plate and said spacer fixed in said counterbore.

2. A fuel metering device for use in gaseous fuel pilot burners, comprising an elongated body member having an externally threaded portion for detachable assembly with a pilot burner, said body member having a longitudinal fuel passageway therethrough, a counterbore at the outlet end of said passageway, a circular orifice plate having a single concentric central metering orilice and being slidably received in said counterbore, a cylindrical spacer member having a concentric central passageway therethrough and being slidably fitted in :said counterbore and overlying said orifice plate in face to face contact therewith at one end, a transverse diffusing bar rigidly attached to the other end of said spacer and lying across the transverse center thereof so as to bisect said metering orifice, and means for rigidly retaining said orifice plate and said spacer in said counterbore.

JAMES A. WRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 329,717 Chapman Nov. 3, 1885 2,187,779 Gardner Jan. 23,1940 2,316,832 Aghnides Apr. 20, 1943 V V FOREIGN PATENTS Number Country Date 188,462 Great Britain Nov. 16, 1922 509,665 Germany Oct. 11, 1930

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