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Publication numberUS3045278 A
Publication typeGrant
Publication dateJul 24, 1962
Filing dateApr 3, 1959
Priority dateApr 3, 1959
Publication numberUS 3045278 A, US 3045278A, US-A-3045278, US3045278 A, US3045278A
InventorsPotter Charles
Original AssigneeEngelhard Ind Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Fiber forming torch
US 3045278 A
Abstract  available in
Images(2)
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Claims  available in
Description  (OCR text may contain errors)

July 24, 1962 c. POTTER 3,045,278

FIBER FORMING TORCH Filed April 5, 1959 2 Sheets-Sheet 1 20 Fue. s

Prfe/my Zane 42 34 52 ATTORNEYS July 24, 1962 c. POTTER 3,045,278

FIBER FORMING TORCH Filed April 5, 1959 2 Sheets-Sheet 2 INVENTOR. CHARLES POTTER ATTORNEYS United States Patent Office 3,045,278 Patented July 24, 1962 3,045,278 FIBER FORMING TORCH f l Charles Potter, South Orange, NJ., assigner to Engelhard Industries, Inc., Newark, NJ., a corporation of Delaware Filed Apr. 3, 1959, ser. Ne. 803,928 1p1 Claims. (Cl. 11s- 2.5)

This invention relates to combustion chambers or torches for forming tlber-s of materials such as quartz which have very high melting points.

'Fine quartz hbers are very diicult to make and are relatively -expensive with respect to many other fibers. This difficulty and high cost results principally from the high melting point of 17507 C. for quartz.

' Prior .techniques which have been proposed tor forming quartz fibers have employed commercial metallizing guns or torches and various other arrangements. When these prior art `arrangements have been applied to the formation of quartz fibers, however, it has been found that there is very poor efliciency in the absorption of heat from the flame by the quartz, .and fthat the quartz fibers are formed at a very low rate, due to Ithis poor utilization of heat.

Accordingly, increasing the production nate and reducing the cost of making libers of high melting point materials iare the principal objects of the present invention. Collateral objects of the invention include increasing the heat transfer etliciency and protecting the torch from unnecessarily elevated temperatures. Stated in simpler terms, it is desired to obtain more output per torch land more -output per unit volume of input gas.

In addition, rods or laments of small diameter have normally been used yas a starting point in prior art proca combustion chamber having an inlet end through Which -a rod of quartz or other high melting point material is fed. Quartz fibers and gases lare exhausted from the other end. The end of the combustion chamber through which the quartz rod is fed is very nearly lair tight, and may therefore be termed the closed end of the chamber, in contrast to the opposite open or outlet end through which the quartz bers and other gases leave the combustion chamber. In the combustion chamber, suitable high temperature fuel and oxygen are applied peripherally and generally at right angles to the axis of the rod, at a point spaced from the closed end of the combustion chamber. This direct application of heat to the quartz rod, generally at -right angles, permits high efficiency heat transfer to the quartz rod and raises the temperature of the rod to the melting point. Spacing the point of application of flame `to the rod from the closed end of the chamber permits suitable preheating of the rod. y

In addition, yaroundI the inner surface of .the outlet end of the combustion chamber, air, steam or other gas under pressure is directed toward the quartz rod .and outwardly from ther combustion chamber. This attenuates the molten quartz and draws iibers from it. It also has an aspirating or lsuction effect, and draws the flame and the combustion products centrally along the axis of the quartz rod to keep `the molten quartz hot yas fibers are drawn olf. Furthermore, the -ame and the hot combustion products are drawn out of the combustion chamber and away from its walls .so that these walls `are not heated unduly. Formation of bers depends upon having the 'nod of'high melting point material is fed, an open end,

arrangements for directing Ia flame generally perpendicular to the axis kof the rod, yand va peripheral outlet near the open end of lthe chamber for providing a forceful annular gas jet directed toward the rod and outward fnom the chamber.

In accordance with an additional feature of the invention, fthe llame may be applied to the rod at alregion which is spaced from the closed end of the combustion chamber by a distance which is more than the inner radius of the chamber, to provide a preheating zone. Small 'bleed holes may be provided .to supply lair under pressure to lthe preheat lzone of the combustion chamber to preclude the accumulation of silica vapor.

In accordance with a further feature of the invention, air, steam or -other gas under pressure may be supplied through `a jacket encompassing the combustion chamber both rto the bleed holes in the preheat portion of the chamber and to the peripheral asprating outlet near the open end ofthe combustion chamber. This arrangement serves to cool the inner wall of the combustion chamber and prevent overheating. `In addition, the heat transfer from the combustion Ichamber increases the temperature and energy of the air stream thus increasing its velocity.

The aspiration effect provided by the peripheral outlet has the advantage of permit-ting the combustion of larger gas volumes than would otherwise be possible. This increases the velocity of the gases forming the exit jet and greatly increases the frictional shearing forces which produce the quartz fibers. The additional hea-t resulting from the eliicient use of the flame and large volume of combustion gas permits the use of quartz rods of relatively larger diameter in the process. These factors account to a considerable extent for the greatly increasedv 'FIGURE l is a cross sectional view of a combustion chamber or torch `for forming fibers of high melting point material in accordance with the present invention;

FIGURE 2 is an alternative embodiment of the comlbuston chamber of 'FIGURE 1 in which a cooling jacket is provided; Y

FIGURE 3 shows another modification of the invention in which fuel gas and oxygen are mixed within the combustion chamber itself; and FIGURE 4 shows another fpost-mix arrangement for a combustion chamber. l With reference to the drawings, FIGURE 1 shows an illustrative torch or combusti-on chamber for formingl quartz rod 16 is fed into the closed end of the combustion chamber through the sealing element 18 which prevents lbackfring through the closed end of the chamber.l

The torch of FIGURE l 3 Suitable rollers 20 and 22 may provide the drive for feeding the rod 16 into the combustion chamber.

The quartz rod is heated by llame from the jets 24 through 31 which are spaced peripherally around the inner surface of the combustion chamber. Annular chambers 34 and 36`supp1y premixed fuel and oxygen to the jet openings 24 through 31. The fuel is applied to the quartz rod 16 in a direction generally perpendicular to the axis of the rod. More specifically, as indicated by the arrows l38 and 40, for example, the flame from the jets is applied directly to the surface of the quartz rod 16. This combustion directly on the surface of the rod is particularly effective for transferring heat to the rod. Accordingly, full heating of the quartz rod 16 is obtained up to the temperatures of about 2000" C. which are desirable for the forming of quartz fibers.

' In order to bring the quartz rod 16 up to the melting point, a suitable preheating zone 42 is provided within the combustion chamber. The preheating zone is provided both by the proper orientation of the jets 24 through 31 and lby the spacing of these jets at a significant distance from the closed end of the combustion chamber. In this regard, it is noted that the jets are spaced from the closed end of the combustion chamber .fby a distance which is greater than the minimum inner radius of the combustion chamber. While this distance is not overly critical, a distance of this general order of magnitude, or a somewhat greater distance, is desirable in order to permit adequate preheating of the rod in bringing it gradually up to the required high melting temperature.

In regard to the orientation of the jets 24 through 31, it has been mentioned that they should be oriented generally perpendicular to the axis of the quartz rod 16. In this regard, slight deviations from exact perpendicularity within 45, or preferably within 30 of this angle, are within the contemplation of the present invention.

Toward the open end 14 of the combustion chamber, a blast of air or steam is directed through the peripheral opening 44 toward the quartz rod and toward the open end of the combustion chamber. Air or steam to be applied to the peripheral opening 44 is supplied from the tube 46 via the annular opening 48. With regard to the connection of the tubes 46, 50 and 51 to the torch assembly, conventional tube fittings may -be employed. These ttings are not shown in detail in the present drawing. The Width of the peripheral opening 44 may be adjusted by rotating the annular member 54 at the open end 14 of the combustion chamber. As the member 54 is turned, its position with respect to the remainder of the combustion chamber is shifted by means of the screw threads 52, and the width of the opening 44 is changed.

The quartz rod is preheated in the region designated 56; it is drawn down the region designated 58; and it is attenuated and blown into fibers in the region designated 60 in FIGURE l. It is again noted that the fibers are separated from the rod as the result of :frictional shearing forces of the high velocity hot gases on the portion of the quartz Which `has been heated to the liquid phase.

The air blast through the peripheral opening 44 provides an aspiratng elect for the combustion chamber, and increases the velocity of the gases at the exit opening of the combustion chamber and particularly in the region 60 as shown in FIGURE 1. In addition, the flames from the jets 25 and 31, for example, are deflected as indicated by the arrows 62 and 64 toward the open end 14 of the combustion chamber. The ames are thus drawn along the molten portion 58 of the quartz rod and maintain it in the heated condition. Furthermore, the flame and the combustion products are directed away from the walls of the combustion chamber so that it is not overheated. As can be readily imagined, this overheating problem is a serious one with temperatures of up to or slightly more than 2000 C. being present ae the surface of the quartz 1'0 FIGURE 2 is an alternative embodiment of the arrangement of FIGURE l. The principal -additional feature of the arrangement of FIGURE 2 lies in the use of a cooling jacket 72 which encompasses the major portion of the combustion chamber. The arrangement of FIGURE 2 also shows a premixing jacket 74 in which the oxygen and fuel gas are combined prior to application to the jet 76 and the other peripherally located jet openings. In order to avoid the accumulation of silica vapor in the preheat zone 78 of the furnace, small air bleed holes 80 and 82 are provided, together with suitable adjusting screws. Air flowing from the jacket 72 under pressure through these small bleed holes prevents the undesired accumulation of silica vapor in the preheating zone 78 of the furnace. The tubes 84 and 86 pass through the cooling jacket 72 from the premix jacket 74 to the jet openings, without materially interfering with the flow of air from the closed end of the combustion chamber toward the peripheral opening 88 at the open end of the combustion chamber. Suitable drill holes 90 are provided for the passage of air from the cooling jacket 72 to the annular chamber 92 at the open end of the combustion chamber. It may be noted again that, in addition to the cooling effect and the convenient use of bleed holes, the arrangement of FIGURE 2 provides for the transfer of heat and the resultant increase in pressure of the gas applied to the outlet 88. In other respects, the operation of the torch of FIGURE 2 is generally similar to that of FIGURE 1 as described above.

Two alternative forms of jet supply arrangements are disclosed in FIGURES 3 and 4. In FIGURE 3, fuel gas is supplied to the annular chamber 102, and oxygen is fed to the annular chamber 104. A series of peripheral paired jets 111 through 114 are provided to mix the fuel gas and oxygen within the combustion chamber. This type of arrangement is designated a post-mix arrangement as contrasted with the premix flame jet employed in the arrangements of FIGURES l and 2.

A somewhat more elaborate post-mix arrangement is shown in FIGURE 4. Oxygen is supplied through tube 122 to the outer peripheral jacket 124. Fuel gas is coupled to the inner annular chamber 126 by the tube 128. Small tubes 130 are employed to carry the oxygen through the fuel gas chamber 126 to concentric jet openings such as those designated 132. This arrangement provides an improved mixing of the fuel gas Land oxygen with somewhat less turbulence than that provided in the arrangement of FIGURE 3. With regard to the open end of the combustion chambers of FIGURES 3 and 4 and the other associated equipment which is not shown, these arrangements would correspond substantially with that of FIGURES 1 and 2.

Any of a number of different types of fuel may be employed for combination with oxygen. However, it is considered that acetylene, propane, methane or hydrogen are most suitable. The oxygen may be supplied under a pressure of from 15 to 90 pounds per square inch, for example, and the fuel gas at any suitable pressure greater f than 15 pounds per square inch. The air or steam for aspiratng and cooling purposes may be at any desired pretslsure, preferably from .10 to pounds per square mc For simplicity of construction and to provide a preferred embodiment of the invention, the openings for the fuel have been shown as separate peripheral jets, and the opening for the aspiratng blast of air or steam .has been disclosed as a continuous annular opening. However, the flame jets could be of a continuous annular form and the blast of air could be provided by a series of jets directed toward the quartz rod and the open end of the combustion chamber.

In the present discussion, the terms fused quartz and fused silica have been used loosely. In general, these terms and the additional terms silica glass and quartz glass are employed to refer to various types of fused comme silica, and the different terms are employed to indicate the degree of transparency of the material. However, the terms employed in the present specification are intended to apply to quartz or silica in any of its known forms. Other details regarding terminology, the state of fused quartz at various temperatures and so forth are set forth in the National Bureau of Standards Circular 569 on Fused Quartz Fibers, issued January 25, 1956. In addition, the principles of the present invention are applicable to other high melting point materials such as the,

ceramics and other similaror related materials having melting points of the same order of magnitude as that of fused quartz or silica.

The presen-t invention has been described inconjunction with a circular torch or combustion chamber, and such an arrangement isto be preferred. It is recognized, however, that quartz rods of rectangular or square shapes could also be processed by a torch or combustion chamber in accordance with the principles of the present invention, and the combustion chamber would then have a generally corresponding shape.

It is to be understood that the above described arrangements are illustrative of the application of the principles of the invention. Numerous other arrangements may be devised by those skilled in fthe art without departing from the spirit and scope of the invention.

What is claimed is:

l. In combination, a combustion chamber having a closed end and an open end, means for directing a rod of high melting point material through the closed end of said combustion chamber along an axis, toward the open end, means for directing llame generally perpendicularly to the axis, outlet means near the open end of the cham-ber for providing a forceful peripheral gas jet di rected toward said axis and outwardly from the combustion chamber, a -cooling jacket encompassing at least a portion of said combustion chamber, means for coupling gas from said jacket to said outlet means, and means for supplying -gas under pressure to said cooling jacket, whereby -the heat transferred from said combustion chamber to said gas increases the velocity of the gas jet from said outlet4 means.

2. In combination, a combustion chamber having a closed end and an open end, means for directing a rod of high melting point material through the closed end of said combustion chamber along 4an axis toward the open end, means for directing flame generally perpendicul-arly to the axis,said flame directing means being spaced from the closed end of said furnace to provide -a preheating zone, outlet means near the open end of the chamber for providing a forceful peripheral gas jet directed toward said axis and outwardly from the combustion chamber, a cooling jacket encompassing at least a portion of saidv combustion chamber, including said preheating zone, the wall between said cooling jacket and the preheating zone o-f said combustion chamber being provided with at least one small bleed hole lfor precluding the accumulation of silica vapor, means for coupling gas fro-m said j-acket to said outlet moana-and means for supplying gas under pressure to said cooling jacket.

3. In combina-tion, a combustion chamber having a closed end and an open end, means for directing a rod of high ymelting point material through the closed end of said combustion chamber along an axis toward the open end, means for directing llame -generally perpendicularly to the axis all around said rod, said combustion chamber including a preheating zone between said closed end and said -ame directing means, said Zone having a length at least equal lto the radius of said chamber, means including an outlet near ythe open end of the chamber Ifor providing a forceful peripheral gas jet directed toward said rod and outwardly from the combustion chamber, and means for bleeding gas under pressure into said preheating zone of said combustion chamber.

4. In combination, a combustion chamber having a closed end and an open end, means .for directing a rod of high melting point material through the closed end of said combustion chamber along an axis toward the open end, means for directing ilametoward and generally perpendicularly bto the axis, means for bleeding air under pressure into said combustion Vchamber between said closed end and said llame directingmeans, and means including a peripheral outlet near the open-end of the chamber for providing a forceful gas jet directed toward said -axis and outwardly from the combusti-on chamber.

5. In combination, a combustion chamber having a first open end and a second end having an aperture, said open end being constricted with respect to the cross section of said combustion chamber to Vprovide a nozzle, said nozzle beingan extension of Ithe combustion chamber, means for directing a rod of fused quartz through said -aperture along an axis toward the open end of said combustion chamber, `means for directing flame generally perpendicularly to sa-id axis to heat said rod to its melting point, and means including a peripheral outlet near the open end of Kthe chamber for providing a forceful gas jet .Y

directed toward said -axis and outwardly from the combustion chamber through the nozzle.

6. In combination, a combustion chamber having 'a closed end and 'an open end, said open end being constricted with respect to the cross section of said combustion chamber to provide a nozzle, said nozzle being an extension of the combustion chamber, means for directing a rod of high melting point material through the closed end of said combustion chamber along an axis toward the open end, means for directing flame generally perpendicularly to the axis, and outlet means near the open end of the chamber for providing a forceful peripheral gas jet directed toward said axis and outwardly from the combustion chamber through the nozzle.

`7. In combination, a combustion chamber having a closed end and an open end, said open end being constricted with respect to the cross section of said combustion chamber to provide a nozzle, said nozzle being lan extension of the combusti-on cham-ber, means for directing a rod of high melting point material through the closed end of said combustion chamber along an axis toward the open end, means yfor directing llame generally perpendicullarly to the axis all around said rod, said combustion chamber including a preheating zone between said closed end `and said llame directing means, said zone having a length which is at least equal to the radius of said chamber, and outlet means near the open end of the chamber for providing a forceful peripheral gas jet directed toward said axis and outwardly from the combustion chamber through the nozzle.

8. In combination, a combustion chamber having a closed end and -an open end, said open end being constricted with respect to the cross section of said combustion chamber to provide a nozzle, said nozzle being an extension of the combustion chamber, means for directing la rod of high melting point material through the closed end of said combustion charnbel along an axis toward the open end, means for directing flame toward yand generally perpendicularly, to the axis, and means including a continuous peripheral outlet near the open end of the chamber for providing a forceful gas jet directed toward said axis and outwardly from the combustion chamber through the nozzle.

9. In combination, a combustion chamber having a closed end and an open end, said open end being constricted with respect to the cross section of said combustion chamber to provide a nozzle, said nozzle being an extension of the combustion chamber, means for directing a rod of high mel-ting point material through the closed end of said combustion chamber along an axis toward the open end, means for directing jets of premixed fuel gas and oxygen toward and generally perpendicularly to the axis, and means including an outlet near the open end of the chamber for providing a forceful peripheral gas jet 7 directed toward said 'axis and outwardly from the combustion chamber through the nozzle.

10. In combination, a combustion chamber having a closed end and lan open end, said open end being constricted with respect to the cross section of said combustion chamber to provide a nozzle, said nozzle being an extension of the combustion chamber, means for directing a rod of high melting point material through the closed end of said combustion chamber along an axis toward the open end, means for directing llame toward and generally perpendicularly to said axis, said llame directing means including separate jets for fuel gas and oxygen having outlets located at common points around said rod, and means including an outlet near the open end of the chamber for providing a forceful peripheral gas jet directed toward said axis outwardly from the combustion chamber through the nozzle.

11. A combination as defined in claim 10 wherein said fuel gas and oxygen jets are concentric.

References Cited in the le of this patent UNITED STATES PATENTS

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1856679 *Jul 22, 1925May 3, 1932Gen Motors Res CorpApparatus for comminuting metals
US2175225 *Oct 11, 1934Oct 10, 1939Owens Corning Fiberglass CorpMethod of making glass wool
US2585496 *Apr 21, 1949Feb 12, 1952Johns ManvilleMethod and apparatus for the manufacture of fine fibers
US2724866 *May 4, 1953Nov 29, 1955Gustin Bacon Mfg CoProcess of shredding glass fibers from a stick of glass batch
US2822579 *Mar 30, 1953Feb 11, 1958Alexander SilvermanMethod of making glass filaments
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3184092 *Sep 9, 1960May 18, 1965Quartz & Silice S AThin-walled pressure vessels and method of manufacture
US3436792 *Nov 22, 1966Apr 8, 1969Hans Heinrich Wilhelm HenchApparatus for producing strands or granules from liquid material
US3540870 *May 7, 1968Nov 17, 1970Us Air ForceApparatus for drawing and coating quartz glass fibers
US3652248 *Jun 9, 1970Mar 28, 1972Edward J Mellen JrProcess for redrawing silica glass rods
US3736094 *Jun 1, 1971May 29, 1973Johns ManvilleApparatus for generating high energy gaseous blast
US3944640 *Jun 14, 1973Mar 16, 1976Arthur D. Little, Inc.Method for forming refractory fibers by laser energy
US4012213 *Mar 19, 1975Mar 15, 1977Arthur D. Little, Inc.Apparatus for forming refractory fibers
US4181256 *May 15, 1978Jan 1, 1980Ryoichi KasagiMetal melt-spraying method and equipment
US4578098 *Jun 15, 1984Mar 25, 1986At&T Technologies, Inc.Apparatus for controlling lightguide fiber tension during drawing
US5219456 *Mar 27, 1992Jun 15, 1993Theriot Joseph GWell test burner
US5651819 *Jun 24, 1993Jul 29, 1997The Idod TrustContinuous tube forming and coating
US5931984 *Apr 22, 1997Aug 3, 1999Alcatel Fibres OptiquesDevice for drawing down an optical fiber preform
Classifications
U.S. Classification65/537, 264/DIG.190, 239/83, 432/246, 432/64, 432/238, 65/120, 239/132.5, 65/DIG.800, 431/238, 432/143, 431/158
International ClassificationC03B37/065
Cooperative ClassificationY10S264/19, C03B37/065, Y10S65/08
European ClassificationC03B37/065