US2614619A

US2614619A - Burner and nozzle tip for projecting hot products of combustion

Info

Publication number: US2614619A
Application number: US781403A
Authority: US
Inventors: Robert A Fuller
Original assignee: Selas Corp of America
Current assignee: Selas Corp of America
Priority date: 1947-10-22
Filing date: 1947-10-22
Publication date: 1952-10-21
Anticipated expiration: 1969-10-21

Description

R. A. FULLER Oct. 21, 1952 f BURNER AND NOZZLE TIP FOR PROJECTING HOT PRODUCTS OF COMBUSTION Filed Oct. 22, 1947 INVENTOR HUBERT AFULLER fw. am

ATTORNEY Patented Oct. 21, 1952 BURNER NOZZLE TIP FOR PROJECT- v ING HOT PRODUCTS OF COMBUSTION Robert A. Fuuer, yilhilaslelphia, Pa., assigner to Selas Corporation of America, Philadelphia, Pa., a corporation of Pennsylvania Application October 22,1947, Serial No. 781,403

The present invention relates to high tempera.- ture gas burners. It is an object of the invention to provide a gas 'burner which will produce ajhigh velocity stream 'of hot gases in the general form of a hollow, truncated pyramid or cone.v It is a further ob- 'ject of the invention to provide a gas burner,

. the nozzle or tip of which will direct the hot,

high velocity products of combustion from a gas burner in a hollow converging pattern.

"According to the presenty invention, a thread of molten material is permittedto fall vertically 'into a horizontally directed stream of "hot, high 'Velocity gases which are so patterned that the thread -is completely enveloped by the gases. rConsequently thev thread is carried by the gases *and is, in effect, exploded by them into a plurality of fine fibersl of uniform quality. t The'various features of noveltywhichcharacterize my invention are pointed'ofut with particularityin thevcla'ims annexed to land forming a part of this specincation, For a better understanding ofthe invention, however, its advan-` tages, and specific objects'attained with its use, reference should be had tothe accompanying drawings and descriptive matter in which I have illustrated and described a preferred embodiment of the invention. In the drawings: A v v Figure 1 is a view, partly in section, showing the apparatus required to make fibers;l

Figure 2 is a section through the burner 5 Figure 3 is a front View of the burner tip; Figure-fl isa section through the burner tip, `taken along lines 4 4 of Figure f fFigure 5fisa figure showing a diierent shape -port in the'burner tip; and i "Figure 6 is a top view ofthe burner tip showing themanner in which the lgas blast is formed.

. In the manufacture'of ne b'ers according to the present invention, there is provided a suitable melting furnace that has a forehearth l in which islocated the molten material 2. The lower portion. of this forehearth is provided with an orice 3 of approximately'l/fg" in Vdiameter through which a stream or thread of molten material may fall; y As the-material falls it will gradually be reduced in diameter to approximately le at a point about 8" .below theorince. By the time itreaches this' point "it will still be molten but lslightlymoreviscous than it was at the exit of Corice' 3*. At this point the'th'read 4 is enveloped iin a* blast of hot gases 5, that are shown diagramfimatically, which ygases are ejected from a burner 6,` l, l Y

"1o claims. (ci. 15s-99) Burner 6 is similar to prior burners of the type in the manner in which the fuel is burned and the hot gases of combustion are produced. yThe tip ornozzle of the burner through which the gases are ejected, however, is of a novel shape,

vand produces a pattern 'of vgases by means of which the method of blowing fine fibers according to this invention may be followed.

l the burner screen.

vend portion of the shell I9.

Referring to Figure 2 of the drawing, itr willfbe seen that the burner 6 included in this invention has a ring-shaped 4base member 1 formed to provide an inlet chamber 8 and an extension 9 that is threaded, and into which maybe connected a pipe I! carrying a suitable supplyof combustible mixture. The base member 1 is formed with an inwardly extending shoulder l2 at its top to receive the lower anged'end I3 of a cricular burner screen I4 having a plurality of small apertures I5 extending therethrough.

At the top face of the base member 'l a ringsh'aped clamping plate i6 is secured by some'suitable means, such as screws Il, with the inner end of the plate overlying the flanged endof In order to obtain a gas tight seal about the screen, a gasket 8, such as asbestos, is interposed between the plateand the base member.

The large end of a cup-shaped shel1 or'outer casing i9 is removably secured to the base member by 'bolts 2l. Within the metal shell 'is provided a hollow body having a cavity forming a combustion space 22 terminating at its upper end `in a discharge orice or outlet. In the" burner illustrated the hollow body comprises a number of par-ts of high temperature refractory material including an annular member 2li which snugly fits around the upper portion of the burner screen.v

About the annular member is disposed the lower end of a cylindrical member 23 which bears against the *clamping plate'li and 'extends upwardly therefrom to the sloping or tapered upper Within this member and forming therewith apart of the refractory space is disposed a second hollow cylindrical member 2li, also of refractory 'mater-iai. The lower end of this member bears against thetop surface of the annular member Eiland the upper end thereof bears against the larger end of an annular member 25 which forms a restricted discharge space. yThis member projects to a point 'substantially even with theA end of the metal shell -and has its opening closed by a burner tipor nozzle 26'.`

Inorder.` to withstand the high temperatures produced "1n the combustion space during the burner tipl or nozzle 26;

,verge toward their outer ends.

enveloped by the hot gases.

operation of the burner, the inner cylindrical member 24 and the upper annular member 25 may be formed of suitable refractory material, such as beryllium oxide which possesses rigidity and strength at high temperatures. 'Ihe outer cylindrical member 23 is preferably formed of refractory material,l such as aluminum oxide, possessing good insulating properties and having adequate strength to Serve as the outer portion of the refractory wall. The burner screen I4 itself, may be formed of refractory material, such as aluminum oxide. Tip or nozzle 26r is shown herein as being formed of a high' temperature resistant metallic alloy, -but itfcould besrnadeof a suitable refractory if desire'dl ,f

The refractory wall parts just described', are

secured to one another and in the outer shell I9 by any suitable firebrick cement as indicated at 21. Such high temperature cementproduces'Y a rigid and unitary burner structure in which all offfthe refractory wallparts are unitedrto form the combustion space';

As isV shown in Figure 2 of the drawing, the outerend of the metal casing" I9 is threaded to receive an annular 'collar 28 having in it a conical opening 29. This opening receives in turn the It will be noted'Y that the annular collar 28-has al cut-out portion 3| that is closed by a washer 32 so that when the lburner tip, the washer, and the annular collar -arein Yassembled relation with. respect tothe outer shell Isasmall annular space is provided.

This spaceY is usedffor circulating vcooling water so thatV the burner tip 2-6 and collar 28 will not become-overheated To thisfend an inlet- 33 and an outlety 34 (Figure 3)\ are provided through Whichthe cooling water may be passed. These parts,` aswell asthev ceramic parts which were described-above, are all cemented together with a suitable .high-temperature'cement so that when they arein assembled relation, as'shown inthe drawing, they will form a rigidy unitary member Vwit-ligas tight joints between each part.

The burner tip or nozzle 26 has in it a port 35v which is substantially U-shaped. This port is .provided with a horizontal portion 36 and two upwardly extending portions 31 and 38 that -con- As shown best in Figuresl and 4-the upwardly extending Iportions ,of the 4slot are cutV at an angle toy the face of the burner tipso that the-r hot gases of combustionvfrom thecombustion chamber 22 passing throughtheport 35 in the tip will take the form Aofha, U, the angle. of theA legs causing the gases to converge; The pattern of the gases is substantially that of a hollow truncated pyramid with a small triangular opening in the top throughfwhich the thread 4 passes. This is best shown in dash linesvin Figure.

There is shownin Figure 5 another shapefor thel burner port. I-nV this case the port 35av is circular virl-'shape except for a short. portion of the arc across the top thereof. This leaves a space through which the thread may fall to .be As in the previously described embodiments, port 35a is larger on the inner face of nozzle or tip 26 than it is on the outer face thereof. ThisA gives a converging pattern to the kport and to the gases passing therethrough so that they form, in effect, a hollow truncated cone with ano'peningin the top there- 6f. Whether the port is shaped as4 shown in Figure 3 or Figure 5, the pattern of the gases, 4looking from above, will be substantially'the same fand similar' to that shown .in Figure. lllngrboth cases the port may be said to be substantially U-shaped with the vertical legs converging. The port may take other shapes as long as the gases passing through it form a closed ypattern with an opening in the top through which the thread 4 of material may fall.

In the operation of th'eburner 6 to' produce a high velocity stream of? the heated products of combustion, a fuel mixture comprising gas and combustion supporting air is supplied through the inlet pipe .Il from a suitable source. When the burnerl isrelativ'ely cool and at a low temperature the' mixture supplied thereto passes through: the inletchamber 8, burner screen I4 and .thecombustion space 22, from which it is discharged throughthe

port

35 or 35a in the burner tip 26. The combustible mixture is initially supplied to the burner' at va relatively low pressure so that the gaseous mixture discharged from this space can be ignited to produce and maintain a flame at the outlet.

When a flame is being maintained at the outlet, the pressure of the gaseous mixturen supplied to theburner may be momentarily reduced sufficiently to cause the flame to backrethrough the outlet in the burner tip and into the combustion space22. When this occurs a plurality of flames are produced and maintained at the upper ends of the small apertures l5 in the burner screenl4.

When theA names are being maintained atthe top of the burner screen, the pressure of the gaseousv mixture supplied to the burner may then be increased. After ashort interval of time the flames` maintained at the top surfaceV of the burner. screen effect such heatingY of the inner refractory lining24 that l.its surface is heatedto a high incandescenttemperature.V The. heating of the inner refractory lining to. ahighly. incandescent condition and radiant heat-therefrom promotes substantially complete combustionv yof the mixture, before the mixturereaches the port inthe burner tip. From this port `in the tip is discharged a high velocity stream of heated gases at a temperature nearly equal to the temperature of the combustion space, and constituting ubstant'ially entirely heated'products of combusion.

In a burner of the type described, the heated products of combustion are discharged from the combustion space through the port in the tip at an elevated temperature of approximately13000" F. and` ata velocity of. .from 800 to.1000 feetper second..

The molten material from the forehearth l falls in a verticalv thread 4 to a point. closely adjacent thefrontof the burner nozzle and between the converging portions of the blast which'are ejected from the upstanding portions of thenozzle openings as shown in Figure 6. This thread of material will fall until it reaches thev lower horizontalsection of the blast where ii;v willY be blown to the left in Figure 1. As the thread moves away'from the front ofthe burner, it will be completely enveloped in the high temperature gases of combustion that arel being. discharged through the

port

35 or 35a. I

Becauseof rthe pattern in'` which the gasesare formed asthey leave the burner tip, the thread 4 1s completely enclosed'by these gases. Therefore, there is no possibility of the thread bouncing oi or away from the gases and consequently not beingy reduced. sufliciently in size; Since. the thread d is completely .enclosed by the gases which are. above the temperature at which1 the material melts, the material while being carried v.5 with the blast will be remelted to an extremely fluent state and blown in a fine spray in the direction of the gas iiow. This fine spray of material forms a high grade of fibers.

While in accordance with the provisions of the statutes I have illustrated and 'described the best form of embodiment of my invention now known 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 of my invention, as set forth in the appended claims, and that in some cases certain features of my invention can be used to advantage without a corresponding use of other features.

What is claimed is:

l. A gas burner comprising a body having a combustion chamber formed therein, said chamber having an inlet opening at one end and an outlet opening at the other'end, means to supply fuel to be burned to the inlet opening of said chamber,` a tip to close the outlet of said chamber, means to fasten said tip to said body, said tip being provided with an opening throughwhich the hot products of combustion produced in said chamber may be exhausted, the opening in said tip being substantially U-shaped with the legs of theL U being closer together at their unjoined ends than at their joined ends.

2. A gas burner comprising a metallic shell, a ceramic lining in said shell to form a combustion chamber having an inlet for fuel and combustion air and an outlet for the products of combustion, a water cooled annulus attached to said shell surrounding said outlet, a tip member held in position over vsaid outlet by said annulus, said tip member being provided with an outlet port therein through which the Aproducts of combustion pass, said port being substantially U-shaped, the portions of the port forming the legs of the U- converging from the side of the tip in the combustion chamber to the other side thereof whereby the gases leaving said port will iiow in a converging pattern.

3. A gas burner comprising a hollow body forming a combustion chamber having an inlet opening and an outlet opening through which a combustible mixture and products of combustion may pass respectively, a tip member, means lto attach said tip member to said body to close the said outlet opening, said tip member being provided with a port through which the products of combustion flow said port being substantially U-shaped and of substantially uniform cross section, the portions of the port forming the legs of the U converging from the side of the tip in the combustion chamber to the other side thereof whereby the gases leaving said port will flow in a converging pattern.

vopening comprising a straight portion and a separate inclined portion connecting at an acute angle with each end of said straight portion.

6. A burner tip of claim 5 in which the inclined portions are closer together on the outside surface than they are on the inside surface of said material.

'7. A gas burner comprising a body having a combustion chamber formed therein, the chamber having an inlet opening at one end and an outlet opening at the other end, means to supply fuel to be burned in said chamber, a tip to cover the outlet end of said chamber, means to attach said tip to said body in a position to close the outlet opening of said chamber, said tip being provided with a substantially flat surface being formed with a slot through which products of combustion may be discharged, said slot having a straight portion and two converging portions communicating at an acute angle with said straight portion at the ends thereof, each of said converging portions being so formed that the openings on the side of said tip toward `said chamber are further apart than the openings on the opposite side of said tip.

8. A gas burner comprising a body having a combustion chamber formed therein, said chamber having an inlet at one end and an outlet opening at the other end, a tip for said burner attached to said body to close the outlet opening of said chamber, said tip being provided with a substantially flat surface having an opening therein comprising a straight portion and a pair of converging portions each communicating with an end of said straight portion at an acute angle thereto.

9. A tip for a burner comprising a body of material provided with a port therein, said port being substantially U-shaped and of substantially uniform cross section, the portions of the port forming the legs of the U converging from` one side of the body of the material toward the other side thereof whereby gases passing through said port from said one side will fiow in a converging pattern.

10. A tip for a gas burner and through which hot products of combustion are to be discharged comprising a body of material having opposed faces,'said body having an opening, said opening being in the shape of an arc and extending through more than the opening being of substantially uniform cross section and larger on one face of said body than on the other face thereof whereby gases iiowing through said opening from said one face will flow in a converging pattern.

, ROBERT A. FULLER.

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

UNITED STATES PATENTS Number Name y Date 1,140,655 Bell ,May 25, 1915 1,689,551 Hammond Oct. 30, 1928 1,901,086 Cox Mar. 14, 1933 1,977,406 Powell Oct. 16, 1934 2,175,225 Slayter Oct. 10, 1939 2,178,871 Drill NOV. 7, 1939 2,367,119 Hess Jan 9, 1945 2,427,545 Berger Sept. 16, 1947 2,481,543 Stalego Sept. 13, 1949