US2676650A - Oxidant diffuser for fuel burners - Google Patents

Description

April 27, 1954 R. C. BRIERLY OXIDANT DIFFUSER FOR FUEL BURNERS Filed Feb. 6, 1947 IN V EN TOR.

RALPH C. BRIERLY BY 2 2% M ATTORNEY Patented Apr. 27, 1954 UNITED STATES PATENT OFF ICE OXIDANT DIFFUSER FOR FUEL BURNERS Ralph C. Brierly, Narberth, Pa.

Application February 6, 1947, SeriaLNo. 7263943 7 Claims. (Cl. 158-99) (Granted under Title 35;.U'. 8.. Code (1952),

see. 266-) This invention relates to improvements in diffusers and more particularly to improvements in oxidant diffusers adapted to augment combustion speed in fuel burners.

The optimum form of diffuser. employed in the past comprises a relatively flat cone or disc stamped the form of radiating, petal-like blades or spokes held together at the peripheral edge by'a circular band, said band being either stamped andaffixed to; or cast integral with,.the difiuser. The disadvantages of these forms of diffusers are markedly apparent at high firing rates, when high oxidant pressure and differentials through the registers are being sustained. In such cases, oxidant existing between the petal-like blades of the diffusers at high velocity tends to blow the flames of combustible away from the furnace face of the diffusers and to extinguish them or tear them apart so violently. that some of the combustible is chilled, thereby retarding combustion speed.

The primary object of the invention is to provide a diffuser adapted to impart a swirling motion tothe oxidant passing therethrough.

Another object is to provide a diffuser adaptedto permit the heat release per unit area of oxidant control register throat to be increased above the level practicable with diffusers employed presently.

Another object is to provide a diffuser adapted to -greatly augment the degree of intermixture of oxidant and combustible at the face of. the diffuser so'that the flame clings to the furnace side of the diffuser despite hitherto inordinate oxidant velocities.

A further object is to provide a. diifuser adapted to. disseminate oxidant streams in such a manner that the tendency of the flames to blow away'and' chill is reduced.

Another object is to provide a diffuser adapted to 'intermix oxidant and combustible rapidly.

Still another object is toprovide a diffuser wherewith the flames tend to" remain close to thefurnacefaces of the diffuser, thereby permitting combustion to be completed in shorter furnace lengths.

A further object is to provide a diffuser wherewith flame equilibrium is obtained proximate the furnace face of the diffuser.

Further objects and advantages of this invention, as well as its construction, arrangement and operation; will be apparent from the following description in connection with the accompanying drawing, in which Fig. 1 is an isometric view of a diffuser, partly in section, showing a preferred embodiment of the invention;

Fig. 2 is an isometric view of a modified form of the: invention, shown partly in section;

Fig. 3; is an. isometric view of another modified form: thereof, shown partly in section; and

Fig; 4 is an isometric. view of another modified form thereof, shown partly in section.

Similar numerals refer to similar parts throughout the several views.

The diifuser ll comprisesia plurality of blades or deflectors I3 in. spaced relation. secured to and: radiating from the hub of a conduit 15, which is: adapted to carry combustible to an injector; (not. shown) seated in the register distance. piece l1, said blades l'3. being arcuate in. crosssection and increasing in width. as they diverge radially from the conduit l5, common-.- ly disposed, and" defining a first shallow cone or colloid, and a plurality of blades or deflectors I19- in spaced relation radiating from said end of the conduit t5, said blades 19 being arcuate in cross-section and increasing in width as they diverge radially from the conduit I5, commonly disposed with their curvature opposite that of blades l 3 and overlapping the edges of the blades t3, and defining a second shallow cone or concid. A cowl 20 and associated conduit 22 forms a passageway 24 for ingress of oxidant to the diffuser and: the overlapping deflectors l3 and [9 provide entrance passages 35 and exit passages It is apparent that the construction above described effects a turbulence in the oxidant stream passing. through. from the outer face l2 to the furnace face [4 of the diffuser, and subdivides such stream into a multiplicity of oxidant streams adapted to facilitate control of the shape and extent of the flame and intermixture of oxidant and combustible, thereby increasing combustion. efficiency.

As shown in Fig. 2 an alternative construction adapted. to accomplish the same objects provides a plurality of blades or deflectors 2| in spaced relation radiating from the end of a conduit l5,which. is adapted to carry combustible to aninjector (not shown) seated in the register distance piece I 1, said blades 2| being arcuate in. cross-section and increasing in width as they diverge from the conduit l5, commonly disposed, and'defining a first paraboloidor conoid', and a plurality of blades or deflectors 23 in spaced relation radiating from said end of the conduit I5, said blades 23 being arcuate in cross-section and increasing in width as they diverge radially from the conduit 15, commonly disposed with their curvature opposite that of the blades 2| and overlapping the edges of the blades 2|, and defining a second paraboloid or conoid.

As shown in Fig. 3, another alternative construction adapted to accomplish the same objects provides a plurality of blades or deflectors in spaced relation radiatin from the end of a conduit l5, which is adapted to carry combustible to an injector (not shown) seated in the register distance piece ll, said blades 25 bein arcuate in cross-section and increasing in width as they diverge in the path of a helix from the conduit 15, commonly disposed, and. defining a first paraboloid or conoid, and a plurality of blades or deflectors 27 in spaced relation diverging in the path of a helix from the conduit l5, said blades 21 being arcuate in cross-section and increasing in width as they diverge, commonly disposed with their curvature opposite that of the blades 25 and overlapping the edges of the blades 25, and defining a second paraboloid or conoid.

As shown in Fig. 4, another alternativ construction adapted to accomplish the same objects provides a diffuser constructed in the following manner; A plurality of spaced support bars or spreaders 29 support a plurality of annuli SI and a plurality of spaced support bars 29' support a plurality of annuli 33, said bars 29 and 29' securing the annuli 3| and 33 in spaced relation. A plurality of annuli 3|, semi-circular in cross-section, commonly disposed in spaced relation and facing the chamber defined, which increases in diameter as said annuli recede from said conduit l5, are secured to said spreaders 29 and a plurality of annuli 33, semi-circular in cross-section, commonly disposed in spaced relation and facing away from the chamber defined, which increases in diameter as said annuli recede from said conduit l5, are secured to said spreaders 29 intermediate the annuli 31, said annuli 33 overlapping the edges of adjacent annuli 3| and the annuli 3| and 33 defining a frustoconoidal member.

Various modifications and changes can be made in the subject device without departing from the scope of the invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

I claim:

1. A fuel burner oxidant diffuser for a fuel burner having a fuel injector conduit comprising a first plurality of spaced arcuate blades secured to and diverging in a helix of constantly increasing diameter from said conduit and defining a frusto-conoidal member, and a second plurality of spaced arcuate blades secured to and diverging in a helix of constantly increasing diameter from said conduit, disposed with their curvature opposite that of and overlapping said first blades and defining another frusto-conoidal member and oxidant supplyin means communicatin with the conoidal members for injection of oxidant from said members.

2. A fuel burner oxidant diffuser for a fuel burner having a fuel injector conduit comprising a plurality of support bars secured to and radiating from said first conduit, a first plurality of spaced annuli secured to a first plurality of said bars and defining a frusto-conoidal member, said annuli being arcuate in cross section, and a second plurality of spaced annuli secured to a second plurality of said bars and defining another frusto-conoidal member, said second annuli being arcuate in cross-section and disposed with their curvature opposite that of and overlappin said first annuli, one edge of the annulus that is remote from said conduit being proximate the peripheral edge of the frusto-conoidal member defined and oxidant supplyin means communicating with the conoidal members for injection of oxidant from said members.

3. An oxidant diffuser of a fuel burner, said diifuser comprising an element having a furnace face and a second face, said element having passages therethrough, each of said passages having an exit in said furnace face and an entrance in said second face, means for supplying oxidant under pressure to said second face for flow through said passages, said element being so shaped that the exits of said passages lie substantially in the lateral surface of a cone and discharge said oxidant towards the axis thereof, and a, plurality of arcuate deflectors, each of said deflectors overlying the exit of one of said passages with the concave side of said deflector towards the exit, each of said deflectors being spaced from the respective exit and deflect the flow of oxidant issuin therefrom into at least two streams flowing in opposite directions from one another and at substantially a right angle to the direction of flow of the oxidant issuing from said respective exit.

4. The oxidant diffuser of claim 3 wherein said passages are of reduced cross-sectional area at said furnace face to accelerate the flow of said oxidant impinging said deflectors.

5. The oxidant diffuser of claim 4 wherein the deflectors are spaced from one another at such a distance that the flow of oxidant from one deflector impinges the flow of oxidant from an adjacent deflector.

6. The oxidant deflector of claim 5 wherein the exits of th passages and the respective deflectors associated therewith are elongated.

'7. The oxidant deflector of claim 6 wherein the ,element comprises strips of material of arcuate cross-section positioned so that the concave face thereof forms said furnace face and the spaces between said strips form the elongated passages.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 704,895 Martin July 15, 1902 1,494,013 Peabody May 13, 1924 1,740,985 Irish Dec. 24, 1929 1,830,773 Stillman Nov. 10, 1931 1,995,861 Muraki 1 Mar. 26, 1935 2,143,259 Clarkson Jan. 10, 1939 2,341,682 Andrews Feb. 15, 1944 2,380,463 Poole July 31, 1945 FOREIGN PATENTS Number Country Date 168,969 Switzerland July 16, 1934

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