US2571336A - Gaseous fuel burner for furnace walls - Google Patents

Description

Oct. 16, 1951 R. E. BUCKHOLDT GASEOUS FUEL BURNER FOR FURNACE WALLS Filed Oct. 2 1946 ROBERT E. BUCK OLDT- M iwgww Patented Oct. 16, 1951 OFFICE GASEOUS FUEL BURNER FOR FURNACE WALLS Robert E. Buckholdt, Salem, Ohio, assignorto The Salem Engineering Company, Salem, Ohio,

a proprietorship Application October 2, 1946, Serial No. 700,783

This invention relates to gaseous fuel burners, and has among its principal objects the provision of a burner of the gas and air mixing type which is of materially simplified and dependable construction but which nevertheless has improved performance characteristics as regards the volume of supplied combustion air and as regards the thorough intermixing of the gaseous fuel and air.

A further object of the invention is the provision of a gaseous fuel burner of such improved design that deposition and/or escape of combustible colloidal carbon particles is materially reduced.

Another and more specific object of the invention is the provision of a simple but dependable gaseous fuel burner particularly adaptable for use in a furnace wall having a diverging burner port formed of refractory material and when so adapted having the improved characteristic of effecting sufiicient incandescence in the port lining to materially assist in effecting complete combustion of the gaseous fuel supplied.

The above and other objects and advantages of the invention will become apparent upon consideration of the following detailed specification and the accompanying drawing wherein there is disclosed certain preferred embodimentsof the invention.

In the drawing:

Figure l is a sectional view of a refractory furnace burner port and an assembled gaseous fuel burner constructed in accordance with principles of the invention;

Figure 2 is a sectional View generally similar to Figure l but showing a modified assembly constructed according to the teachings of the invention;

Figure 3 is a transverse sectional view taken along the line III-III of Figure 1;

Figures 4, 5 and 6 are detailed sectional views taken along the lines IV-IV, V--V, and VI-VI, respectively, of Figure 2; and

Figure '7 is an end view of the fuel supply tube of the assembly of Figures 1 and 2.

Referring to the drawing in detail, there is provided concentric inner and outer tubes I II and I I, respectively, and in practice the gaseous fuel is preferably conducted into the tube Ill while air for combustion is conducted into tube I I. To facilitate manufacture and assembly all the ports of the burner are preferably carried by the tube II and to provide means, in turn, whereby the tube II may be readily assembled on a furnace wall, for example, the tube II may be provided 2 Claims. (Cl. 1587) with an integral flange I2 which is arranged to lie against and to be secured to the outer face I3 of the furnace wall I l. Of course, each burner is associated with a burner port and in practice such ports will have their walls built up of refractory material either as an integral part of the furnace wall construction or in the form of separable pre-formed tile structures as is well understood in the art. In either embodiment the ports are usually circular and are of increasing cross sectional area in the direction of flame propagation as shown at I5 in Figures 1 and 2.

The inner end portion of tube II is turned radially inward, as shown, to provide a restricted end orifice It and an inwardly tapering portion II on the inner wall surface of the tube. The inner tube i ii is formed with an inwardly tapered end portion I8 and a closed end which is positioned substantially in the orifice It. It should be apparent that the degrees of taper of the inner wall portion ll of the tube II and of the outer surface portion I3 of the tube Iii are substantially equal so that there will be provided an annular but radially inward air injection space which sweeps across the surface I8 substantially parallel thereto. A series of circumferentially spaced apertures I9 are formed in the tapered wall portion is of the tube I0 and the individual axes of the apertures l9 are normal to the direction of air flow across the surface I8.

The inner end of tube III is accurately positioned in concentric relation in the orifice it by a spider 26 which has a ring portion 2| closely received over the tube Ill and a plurality of integral circumferentially spaced but radially outward extending legs 22 which are closely received in the tube I0 and which are preferably streamlined in a direction of fluid flow in the tube I I as shown in Figure 6. By referring to Figures 1 and 2 it will be observed that the outer end edges of the ring portion 2i are tapered generally complementary to the tapering of surface I? so that a minimum of impedance is offered to the flow of fluid through and out of the tube I I.

In the burner assembly thus far described the orientation of the fuel ejecting apertures I9 is such as to cause a diverging cone of fuel gas to issue from the inner end of the tube I0 and this cone will be traversed at substantially right angles by the converging cone of combustion air issuing from the tube II. There will thus be effected thorough and intimate mixing of air and the lighter components of the gaseous fuel but some of this fuel including substantially all the heavier components thereof will be caused to move along 3 in a diverging cone. Now if the burner thus far described is associated with a tapering port having a refractory wall and having its diverging portion beginning fairly close to the orifice Hi, all as illustrated in Figures 1 and 2, it will be observed that the above mentioned diverging fuel cone will move along and in wiping contact with the diverging surface l5 of the burner port. The diverging fuel cone is, of course, a highly combustible mixture and progressive ignition will take place upon progression of the same along the surface thereby effecting a high heating of the wall surface 15. Upon the burner being in operation a short time the surface I5 becomes incandescent and the resultant highly increased radiation therefrom is highly advantageous in breaking down the more complex components of the gaseous fuel to insure complete combustion. Further, this high radiation has the further beneficial effect of imparting such additional heat to the initial products of combustion which may include free carbon of colloidal particle size that upon subsequent expansion and further intermixing of all the gasses in the port and therefore upon the subsequent co-mingling of the carbon and sufiicient oxygen for combustion ignition will be sustained, thus further effecting complete combustion of the fuel.

In the embodiment of Figure 2 the radiation factor above outlined may be further increased by positioning in the forepart of the diverging burner port a bulbous member 23 which is preferably formed of a highly refractory material as sintered silicon carbide, for example, and in practice the mass 23 may be formed on the end of a rod 24 of a high heat-resistant metal alloy. Rod 24 is rigidly carried by the inner end of tube l0 and, as shown, the principal axis of rod 24 and of the bulbous member 23 is in general continuation of the principal axis of the tube I0. The 4 length of rod 2-1 is determined by the throat depth of the particular burner port with which the assembly is to be used so that the inner or conical portion of the member 23 will be generally parallel with the inner conical portion of the burner port. If required, a protecting sleeve 25 formed either of refractory material as sintered carbide or of a heat-resistant alloy may be positioned about the rod 24 intermediate the end of the tube II] and the inner end of the bulbous mass 23.

The burner of Figure 2 being in operation a very short time the bulb 23 will reach high incandescence and the fuel and air mixture passing through the space intermediate the bulb 23 and the burner port surface [5 will be subjected to extremely rapid radiation heating with the consequent beneficial results explained above in connection with the operation of the burner of Figure 1.

It should now be apparent that I have provided improved gaseous burners of simple and rugged construction but which effect improved results in the completeness of combustion of the gaseous fuel furnished. Further, the herein taught correlation of the burner design with the design of the refractory burner port is thought to be particularly advantageous as regard the efficiency of operation of gas-fired furnaces generally.

The above specifically described embodiments of the invention should be considered as illustrative only as obviously many changes may be made therein without departing from the spirit or scope of the invention. Reference should therefore be had to the appended claims in determining the scope of the invention.

What I claim is:

1. A gaseous fuel burner assembly comprisin in combination a refractory furnace wall having an inwardly diverging burner port, an air conducting tube having a restricted end discharge orifice registering with the inlet end of said port, a fuel injecting tube positioned concentrically with said first mentioned tube and having an inwardly tapering end portion and a closed inner extremity positioned substantially in said orifice, a plurality of circumferentially spaced apertures in the tapered portion of said gas injecting tube, a bulbous member of incandescing material positioned in the forepart of said inwardly diverging burner port and having a conical section spaced radially inward from but substantially parallel with a portion of the wall of said port, and means projecting inwardly from said closed extremity of said gas injecting tube to support said bulbous member.

2. A gaseous fuel burner assembly comprising in combination a furnace wall having an elongated furnace port having an inwardly diverging side wall, an air conducting tube having an inwardly tapering inner wall adjacent its discharge end mounted adjacent the inlet of said port and in alignment therewith, a fuel conducting tube concentrically disposed within said air conducting tube and having an inwardly tapering inner end portion disposed in parallel spaced relation with said inwardly tapering wall of said air conducting tube, said fuel conducting tube having a closed inner end disposed substantially in the discharge orifice of said air conducting tube whereby a converging annular flow of air is caused to move inwardly across the tapering portion of said fuel conducting tube, a series of circumferentially spaced apertures in the tapered portion of said inner tube for the emission of gaseous fuel, an elongated support carried centrally on the inner end of said fuel conducting tube and projecting centrally into said port, and a bulbous member of incandescing material mounted on said support and having a conical section spaced radially inward from but substantially parallel with a portion of the side wall of said port.

ROBERT E. BUCKHOLD'I.

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

UNITED STATES PATENTS Number Name Date 2,140,785 Cone Dec. 20, 1938 2,183,596 Trinks Dec. 19, 1939 2,286,857 Holthouse June 16, 1942 FOREIGN PATENTS Number Country Date 765 Great Britain 1877 358,234 Germany Sept. 7, 1922

Images