US2762428A - Gas-fueled radiant burner - Google Patents

Description

Sept. 1l, 1956 E. BLAHA GAS-FUELED RADIANT BURNER Filed Feb. 5. 1953 22\ F G. 4

ATTORNEY.

nited States Patent tion of America, Philadelphia, Pa., a corporation olf` Pennsylvania l Application February 5, 1953, Serial No. 335,240

4 Claims. (Cl. 158-113) The present invention relates to radiant gas burners, and more particularly to the construction of such burners and the distributor tip thereof in which the normal involution of combustion gases is overcome.

Radiant burners of the type with which the present invention is concerned are disclosed in Hess Patent 2,215,079 issued September 17, 1940. Such a burner includes a cup-shaped combustion space in which a combustible fuel mixture is burned to heat the surface of the space to incandescence. As explained in that patent, the fuel is burned as a series of radially directed llames. Since the flames are moving radially away from a ycentrally located distributor member or tip, a low pressure area is created in the center of the combustion space above the tip. As a result of this low pressure area, gases of combustion and, frequently, vapors and gases from the space being heated, are drawn into the center of the combustion space and circulated with the burning'y combustible mixture. Since the distributor tip at the center of the burner is cooler than the remainder of the burner cup surface, the vapors drawn into the combustion space have a tendency to condense on the end of the distributor. Over a period of time, the condensed material will build up on the distributor and obstruct the fuel ports, thus rendering the burner inoperative.

The above mentioned diiliculty occurs particularly` f6 ice vantages and specific objects attained with its use, reference should be had to the accompanying drawings and descriptive matter in which I have illustrated and describedV a preferred embodiment of the invention.

'In' the drawings:

Figure 1' is a sectional View through'one form of the burner; v

Figure 2 is a section of a portion of the distributor taken online 2 2 of Figure l;

Figure 3 is a view partly of vFigure l;

Figure 4 is a sectional view of a different embodiment of the invention, and y 'Figure 5 is a view taken on line 5 5 of Figure 2.

Referring to Figures 1 to 3 of the drawing, there is shown a refractory ceramic block 1 formed of some material such as zircon which is adapted to be inserted in the wall of a furnace or other structure to be heated. The face of this block toward the heated area is provided with a cup-shaped depression 2 having an opening 3 formed in the base thereof extending to the opposite face ofthe block. Concentrically arranged around the portion of the depression adjacent to the base there'of are a series of ripples 4 the purpose of which will be described below.

Extendingfthrough the opening 3 and into the base of the depression 2 is a distributor assembly 5 through which fuel is'supplied to the depression to be burned therein. This assembly includes a cylindrical ceramic member 6 which is mountedon the' exterior of the furnace wallV in'v any suitable manner, so that it will extend into the opening 3 of the block. Mounted in the end of the cylinder 6 and extending into the depression 2 is a distributor member o'r tip 7. This tip is provided around its periphery I with a plurality of radially directed flanges 8 which form between them axially directed channels 9 through which when radiant cup type burners are used in glass furnaces.

and some types of ceramic kilns. In a glass furnace, the glass vapors are carried into the combustion space and condense upon the end of the distributor. After a relatively short period of operation, the end of the distributor is vitriiied and the fuel ports are clogged up. .In some ceramic kilns where there is dust of a uxing nature the same thing occurs. The dust is carried with the combus-A tion gases into the combustion space. It is there deposited on the distributor to clog the fuel ports.

It is an object of the present invention to provide a radiant cup type burner in which the involution of the gases in the combustion space is eliminated. It is afurther object of the invention to provide a distributor tip or member for use with a radiant cup type gas burner which is so designed that it will prevent the involution of gases into the combustion space of the burner.

In practicing the invention, the distributor tip or member is provided with a chamber immediately back of the end extending into the combustion space. This chamber is supplied with fuel mixture from the supply passages. The side of the chamber toward the combustion space is provided with a plurality of openings through which the fuel mixture can be discharged to burn at the end face of the distributor. The burning at the face of the distribua fuel mixture is adapted to ilow into the depression. It is noted that the exterior edges of the flanges are provided with grooves that form a series of threads as indi-v cated at 11, vso that the distributor tip can be threaded into the end of the holder 6 to be maintained therein and properly positioned with respect thereto.

The upperends of the channels 9 bend outwardly in a generally radial directionias shown in Figure 1 of the drawing., The outer ends of the channels are flared as indicated best at 12 in Figure 2. This flaring or widening of the channels at their exits is for the purpose of increasing thevolume and therefore decreasing the velocity of the fuel mixture as it is moving into the depression or combustion space of the burner. The upper end of the distributor is provided with a centrally located depression which is closed by a plate 15 to form a chamber 13 in the end thereof. This chamber is connected with various of the channels 9 by means of small passages 14. As shown herein, there is provided a passage 14 between the chamber 13 and every other one of the channels 9. It

will be obvious that more or less of these passages may be provided if desired. Plate 15 is of a diameter equal to that of the cylinder 6 so the top flaring portions v12 of the channels 9 are closed.l This insures that-the fuel y mixture flowing through the Achannels will be discharged tor increases the pressure at that region sutliciently to in a radial direction. The cap 15 is provided with a plu-` rality of openings 16 so that the interior of the chamber 13 can communicate with the central portion of the combustion space of the burner.

In the operation of the burner, fuel comprising of a combustible mixture of gas and air is supplied from a suitable mixing machine throughfthe cylindrical holder 6 to the channels 9. From these channels, the fuel mixture ilows out through the flaring openings 12 in aradial direction into the combustion space 2 of the burner.

The fuel is ignited and burns as a plurality of radially directed names lwhich are: directed across the surface o f the depression. The flaring openings 12 of the dis;v tributor permit an increase in volume and, therefore, a decrease in velocity of the fuel mixture, so that the mixture can be more readily ignited than would be the case` if it entered thechamber at a high Velocity and consequently ignition will.y take placecloser to the exits ofthe channels.

In addition, the passage of the jets of mixture across the ripples 4 produces a series of concentric low pressurea'reas between the'-` ripples yin which some' of the mixture is trapped to further slow it down and, therefore, insure theimmediate ignition of the mixture so that burning will take place within and along the surface o f the depression regardless of the ignition characteristicsof the fuel being used. As the mixture is burned in the depression, the surfasetlaereat will. behsated 1Q incaadesn SO that radiant heat is projected forwardly fromj the depressioninto the areas to be heated. Normally, all of the mixture will be burned. within. the depression so that only products of combustion willv be projectedv into. the heatedV area.

With, burners of this type, there is produced a lowpressure. region immediately in front of the end of the. tip. vlihis, as explained in the above mentioned Patent 2,215,079., causesan involution of gases toward the center of. the. cup.. With the present burner, however, such involution is done away with because of the construction of thedistributor tip. During the time that fuel is flowing through the channels 9, a portion thereof will. bleed throughthe passages 14 into the chamber 13. This gas. will flow through opening 16 in the cap and be burned in aseries of. small flames in front of the cap. Y The pressurev produced as av result of the gases expanding due to combustion. will prevent the creation of a low pressurearea immediately in front of the distributor and will insure that the. pressure in the entire depression is slightly above. that in the space to be heated. Therefore,`the above mentioned involution of the gases cannot take place.

A. burner of' the type described above is particularly useful in the heating of'glass. furnaces, for example, where the ordinary type of radiant burner combustion gas and vapors are drawn into the depression and condensed upon the surface of the tip. Withthe present construction, this cannot take place, and, therefore, there is no tendency for these vapors'to be drawn into the cup. Consequently, for uses of this type, the useful life of the burner is considerably increased.

The embodiment of the invention disclosed in Figurel 4 is intended to be used with a burner of a larger capacity thank burners of the type shown in Figures l to 3. In this embodiment,l there is provided a burner block 21 havingl Y contour of' member 31'. Thus, the channels 41 extend substantially to the lower end of the distributor.V The uplr ends of channels 41 flare outwardly as indicated at 42 in the drawing and the inner wall of each channel, formed by the upper end of the portion 38, is provided with a groove 43. This leads into a space or chamber 44, the lower wall of which is formedby a partition 4S extending across the interior of the portion 38. The third ceramic piece 33 is. in the form of a disc that is tted to and is attached permanently to the upper end of the member 2x2 at the haring portion 42 ofthe channels. Thus, the disc forms the top of chamber 44 and one wall .of the portions 42 of the channels Where it closes the space be- Y tween thewebs` 39.. Itis noted that. this disc is provided witha series of openings. 46 that extend from the combustion space 22` to the chamber 44'. It is also noted that the upper end of the channels terminate partially in the periphery and partially in the end of the distributor. Thus, gas flowing through them. hasrboth a radial and an axial component.

In assembling the. apparatus, member 31 is threaded to the upper end of the tube 27 and the assembled members 3,2 and 33 are tted over 3.1 as shown in Figure 4 of the drawing and. threaded into the upper end of the tube 25.

Av suitable washer 47 is provided between these parts in order to f orm a pressure tight connection. The entire assembly isthenV moved into the opening 23 in the block until the upper surface of the member 26 bears against the shoulder 24 between they two diameters of the openingp'h23r. A washer 4S of some suitable material such as asbestos is preferably placed between the end of sleeve 26 and the surface 24 in order to insure a tight t between these parts., It is noted that the distributor member is so dimensioned.v with respect to the burner block 21 that the upper en d of the assembly terminates` slightly below the base of the cup.

In the, operation o f this burner, gas under a suitable pressureissuppliedto the tube 27 and air under. a suitable pressure and in an. amount to form a combustible mixture the upper portions of the channels.

a depression' 22 formed in its surface. The base of the 50 blocli;` isl connected with the other face thereof by means of 'an opening 2,3' of two diameters. The junction between the two diameters is dened by a shoulder 24.

I'n this case, the distributor assembly 25 is held in positionin the opening of the block by means of a holder comprising an outer tubular member 26 and an inner tubular member 27 that are fastened together andv in conf centric relation with each other by means of a disc 28. These parts are preferably formed of metal andare welded intoha single unit. It is noted that the outer member 2,6 is 'provided with a supply pipe. 29.

The Y,upper end of the distributor assembly comprises, in this case, three ceramic pieces 31, 32 and 33, the latter two ofwhich arepermanently joined together. The inner ceramic piece 31 is formed in the shape of a cupv and is. provided with. threads as indicated at 34 so that', it may be threaded tothe upper end of the tube 27. This piece has a reduced upper end that is joined to the lower portion. bya sloping surface 35 through whichv extend a plurality of openings 36.

The second ceramic piece 32. comprises an4 outer wall 37 and shorter inner wall 38 that are joined by webs 39. The space between each of the webs forms fuel passages or channels 41. It is noted that the webs 39 extend below with the gas is. supplied through the pipe 29 to the cylindrical member 26. Gas ilows through the openings 26 into the channels 41 and mixes with the air flowing through these. channels to form a combustible mixture in This mixture is discharged. through thev flared. portions 42 of the. channels into the base ofthe cup 22 where it is burned. The contour of the cup is such that concentric low pressure areas created around the base of the cup which tend to pull' the jets o f the mixture outwardly in a radial direction, sothat" they will burn in a plurality of llames along the surface of the cup-shaped depression 22. The surface of the depression is thereby heated to incandescence to supply radiant heat to the region to be -heated in front of the burner. A portion. of the mixture also ows through the channels 43 from the channels 41 into the chamber 44. mixture is discharged through openings 46 on the facen of the. distributor and burns in front of these openings in a' plurality of small flames.

The expansion of the gases created by the burning of the 'mixhrre issuing from. openings 46 creates enough pressure to prevent a low pressure area from occurring in the center of the depression. Therefore, there will be no involution ofthe combustion gases, into the depression. In this manner, the drawing in of any vapors from thearea being heated is prevented. Consequently, there will be no deposit on the front of the burner and the burner will have a much longer life than would otherwise be the case.

From the above, it will be seen that I have provided a burnerv of the radiant cup type which is adapted to be usedv in places where objectionable vapors or dust are in theatmosphereto be heated. This burner operates in such amanner that-.a large amount of radiant heat is produced and projected into the region to be heated without the objectionable involution of gases that was inherent the end of' wall 38 and are shaped to follow the outer 75 inpreviousburnersof this type.

While in accordance with the provisions of the statutes, I have illustrated and described the best form of my invention now know to me it will be apparent to those skilled in the art that changes may be made in the form of the apparatus disclosed without departing from the spirit and scope of the invention as set forth in the appended claims, and that in some cases certain features of my invention may be used to advantage without a corresponding use of other features.

What is claimed is:

1. In a radiant cup type gas burner, the combination of a refractory ceramic block having a pair of opposed faces, one of said faces being provided with a cup shaped depression forming a combustion space, said block being provided with an opening extending from the base of said depression to the opposite face thereof, and means to supply a fuel mixture to said depression including a holder and a distributor carried thereby and extending through said opening toward said depression, said distributor being provided with means forming a plurality of axially extending channels around the same adjacent to the periphery thereof extending from the interior of said holder to said depression and through which fuel ows to said depression, said distributor being provided with an enclosed chamber adjacent to the end thereof toward said depression, means forming passages between some of said channels and said chamber, and means forming passages from said chamber to said depression whereby fuel can flow from said channels through said chamber to said depression to be burned therein.

2. A distributor member for use in a radiant cup type gas burner comprising a substantially cylindrical body having an end thereof adapted to extend into the zone to be heated, means forming around the body a plurality Y of substantially axially extending channels through which fuel is adapted to ow, said channels bending radially outward adjacent to said end, said body being provided with a chamber located centrally of said channels, means forming passages extending between some of said channels and said chamber, and means forming a plurality of passages extending from said chamber to said end whereby fuel can flow from said channels through said chamber and be discharged at said end.

3. A a fuel distributor for use in a radiant type burner comprising a cylindrical block of refractory material, a plurality of flanges projecting radially from the periphery of said body and extending in an axial direction, said body flaring outwardly at one end thereof, said body being formed with a recess in the flared end thereof, said block being formed with a passage etxending from between some of said ilanges to said receses, and a cap attached to the ared end of said body to cover said recess and form a chamber thereof, said cap being provided with a plurality of apertures that extend from the exterior thereof to said chamber.

4. A fuel distributor for use in a radiant type burner comprising a cylindrical member of refractory material, said body being formed with a plurality of axial channels around the periphery thereof, said channels bending radially outward at one end of said body to terminate partly in the end and partly in the periphery of the body, said body being formed near said end with a centrally located chamber that is surrounded by said channels, means forming a passage between some of said channels and said chamber, and means forming a plurality of passages between said chamber and said end of said body.

References Cited in the file of this patent UNITED STATES PATENTS 1,497,099 Keith `Tune 10, 1924 2,474,313 Hess June 28, 1949 2,573,502 Smith Oct. 30, 1951

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