CA1130519A - Fiber formation by use of high velocity gas blast attenuation - Google Patents
Fiber formation by use of high velocity gas blast attenuationInfo
- Publication number
- CA1130519A CA1130519A CA363,656A CA363656A CA1130519A CA 1130519 A CA1130519 A CA 1130519A CA 363656 A CA363656 A CA 363656A CA 1130519 A CA1130519 A CA 1130519A
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- jet
- blast
- glass
- orifice
- stream
- Prior art date
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Abstract
FIBER FORMATION BY USE OF HIGH
VELOCITY GAS BLAST ATTENUATION
Abstract of the Disclosure Method and equipment are disclosed for forming fibers from attenuable material, such as molten glass, by the use of high velocity whirling gas currents or tor-nadoes. Attenuation is preferably effected in two stages, each of which utilizes a pair of high velocity whirling currents or tornadoes, with the gases in the two tornadoes of each pair turning in opposite directions and with the attenuable material introduced into a zone between the tornadoes of each pair.
VELOCITY GAS BLAST ATTENUATION
Abstract of the Disclosure Method and equipment are disclosed for forming fibers from attenuable material, such as molten glass, by the use of high velocity whirling gas currents or tor-nadoes. Attenuation is preferably effected in two stages, each of which utilizes a pair of high velocity whirling currents or tornadoes, with the gases in the two tornadoes of each pair turning in opposite directions and with the attenuable material introduced into a zone between the tornadoes of each pair.
Description
; ~
The present application i5 a di.v.tsion of our copending application Serial No. 290,246, filed November 4, 1977.
Fiber formation from.attenuable material by esta-blishing a pair of counter rotating whirls or tornadoes, known as toration, is disclosed in our Canadian Application No. 196,097. In that known technique, a gaseous blast is generated and a gaseous jet, known as secondary or carrier jet, is also generated, the jet being of smaller cross section than the blast, being directed in a path transverse to the axis of the blast, and having higher kinetic ener~y per unit of volume than the blast so that the jet penetrates the blast. Such a jet penetrating a blast develops a zone of interaction of the jet and blast~
which zone is characterized by the development of a pair of opposit~ly rotating tornadoes between which a zone of :
relatively low pressure occurs at the blast boundary adja~
cent to and downstream of the zone of penetration of the ~-jet into the blast. In this known toration technique t a stream of the attenuable material is delivered to the zone of low pressure, from which the attenuable material en~ers the zone of interaction between the jet and blast and is subjected to the high velocity currents of the whirls or tornadoes, thereby effecting attenuation of the stream and forming the flber.
`, `,,~ ~ ~ . , :
~. .
.
~L~519 ~
As disclosed in the prior application above re-ferred tc~ the stream of attenuable material is delivered or introduced into the zone of interaction by the placement of a discharge orifice for the attenuable material at or substantially at the boundary of the blast. It is a major objective of the present invention to provide for the sep-aration of the discharge orifice for the attenuable material from the boundary of the blast and at the same time to provide for such separation while maintaining stable deliv-ery of the attenuable material into the system. The manner in which this is accomplished will be developed more fully herebelow.
In accordance with one important aspect of the present invention, provision is made for the generation of a pair of counter-rotating whirls or tornadoes, by estab-lishing a gaseous flow or jet and by utilizing certain jet guiding structure or deflector arranged (in the manner more fully described hereinafter) to generate a pair of counter-rotating whirls or tornadoes having therebetween an area of substantially laminar flow also characteriz~d by low pressure with consequent pronounced induction of air. It will be noted that, in accordance with this aspect of the present invention, the pair of counter-rotating tornadoes is generated by guide structure influencing a gaseous flow or jet, rather than by the penetration of ~--a jet into a blast, as in the toration technique disclosed ~;
in the application above identified. The action of the . ~1~1~
deflector not only develops the pair of tornadoes but also provides the substantially ldminar flow low pressure area between the pair of tornadoes, and the present invention contemplates the introduckion or del~very of a stream of attenuable material, for instance~ molten glass, into the influence of the induced air entering the zone or area of laminar flow formed between the pair of counter-rotating tornadoes. This results in introduction of the stream of attenuable material into the laminar flow between the tornadoes and thence into the inEluence of the high velocity currents of the pair of tornadoes, with consequent atten-uation of the stream to form a fiber.
In accordance with another important aspect of the present invention~ the a-ttenuation technique above described, including the generation of the oppositely rotat-ing tornadoes acting on a gaseous jet is used as a first ~-stage of a two-staye attenuation technique, the second stage being effected by delivery oE the jet a~d the atten-uating fiber carried thereby transversely into a blast of larger cross section, the jet still retaining sufficient kinetic energy to penetrate the blast and develop a zone of interaction in accordance with the toration technique ~-describe~ in the above identified applications. This re-sults in in~roduction of the pre]iminarily attenuated fiber into the zone o-f interaction of the jet and the blast, with consequent further attenuation of the fiber.
By the above described operation, a single fiber is formed from a single-stream of the attenuable material, notwithstanding the fact that the stream is subjected to two sequential stages of attenuation/ each of which in-volves the subjection of a stream or fiber to the action of the high velocity currents set up by the two sequential pairs of tornadoes generated in the jet and in the blast.
Employment of the technique according to the invention, has numerous distinctive advantages. In the ln first place, from the foregoing it will be seen that the use of the pair of tornadoes developed by jet guiding means as a first stage of the attenuating operation, serves also as a means for introduction of the attenuating fiber into the zone of interaction between the jet and the blast, i.e. into the torating zone. Thus, this first stage is in effect utilized as a feed or delivery means in relation to the toration operation subsequently carried on in the toration zone between the jet and blast. This use of the ~;
first stage has numerous important advantages. In the first place such use makes it possible for substantial separation of the several components of the system, namely th~ means for generating the blast, the means for generat- ;
ing the jet and the means for introducing or delivering the attenuable material into the system.
' Separation of the components is in turn advan-eageous for a number of reasons including particularly the fact that such separation reduces heat transfer between . .
:
~,1 the three components of the sys~em, in view of which greater flexibility is possible in the maintenance of different temperatures as between the means for generating the blast, the rneans for generating the jet and thé means for sup-plying and admitting the attenuable material. In turn,such reduction in heat transfer between these components makes possible the use of the system for the production of fibers from materials, such as hard glasses, which require relatively high temperatures to bring them to the molten state or consistency appropriate for a~tenuation.
The separation of the components which is made possible according to the present invention, also elimi-nates or reduces the production of unfiberized or improp-erly fiberized particles resulting from sticking of the attenuable material on hot surfaces. In consequence, more uniformly fiberized products are obtainable.
Still further, the employment of the two-stage system of the present invention, in which the first stage serves as a means for feeding the attenuable material into the zone of interaction of the jet and blastJ i.e~ the toration zone, is desirable because it provides a means for stabilizing feed of the attenuable material into the zone of interaction, notwithstanding the substantial separa-tion of the supply means for the attenuable material from th~ boundary of the blast. Indeed, even with quite sub-stantial separation, the feed of the attenuable material ~ ~: , . . . . .
~ 1~;~5~9 i3 stabilized and accurately controlled, which is an impor-tant factor in providing for uniform fiberizing in t~e zone of interaction, i.e. for uniform tora~ion. Because the first stage or Eeeding means utilizes a pair of counter-rotating tornadoes generated in spaced relation by theguiding action of elements positioned to influence the jet, the laminar flow low pressure area between the tor~
nadoes into which the attenuable material is delivered, results in accurate feed of the stream of attenuable mate~
rial from that area into the region between the counter-rotating tornadoes, and this accuracy is maintained even in the event of some misalignment of the supply orifice for the attenuable material with relation to the jet.
' :;, In consequence of this "automatic" compensation ~ ;
for inaccuracies in the point of supply of the attenuable material, hiyh precision machining of certain parts is no longer necessary, for instance parts associated with the feed of a stream of molten glass~ Such high precision of machining is not readily compatible with the very high temperatures encountered in the handling of molten glass, and this is particularly so where very hard glasses or certain other materials such as slags or certain rocks are being fiberized.
,,: ~...
It is also noted that as an alternative, a slot may be employed for admission of the attenuable material in the general manner disclosed in Figures 12 and 12~, L3~5i~
of the prior ~anadian application above re~erred to in which event, supplem2ntary secondary jet9 would be located one beyond each end of the slot.
The technique of the present invention is also of advantage because it may be employed in connection with a wide variety of attenuable materials, includin~ not onl~
various mineral materials as mentioned above, but even certain organic materials which may be attenuable, sùch as polystyrene, polypropylene, polycarbonate and polyamides.
In the two-stage attenuation tech~ique above referred to, the invention also contemplates employment of certain novel interrelated conditions oE operation of -~
the gaseous jet and gaseous blast, providing improved efficiency with respect to power or energy consumption~ ~
Thus, the invention contemplates establishment or a tor-- ;
ating zone of interaction between the jet and blast by employment of lower jet velocities and temperatures than heretofore used in establishing the ~one of interaction between a jet and blast. By employing lower jet tempera-tures (for instance a temperature approximating ambient ;
or room temperature), consumption of energ~ to heat the jet is eliminated and, in addition, the gas of the jet is increased in density. In consequence, the kinetic ener~y level of the jet required for penetration of the jet into the blast is provided at lower jet velociti~s, 51~
thereby effecting further power economies. When employing such lower jet temperatu~es r ~`,t lS, even pos~ible to employ jet velocities well below the vel~city of the blast and still maintain the kinetic energy level of the jet suf-ficiently high to provide the des:ired penetration of thejet into the blast.
The lower jet velocities are still fur~her of advantage in the two-stage attenuation technique herein disclosed because in the first stage of attenuation, in which the st~eam o~ attenuable material is delivered to the jet, the lower jet velocities and temperatures assist in avoiding fragmentation of the stream of attenuable material.
Although, for most purposes, it is conte~.plated according to the technique of the present invention, that the fiberization of the attenuable material be effected in two stayes in the manner generally descxib.d above, it is to be noted that for some purposes the attenuable ;~
material may be subjected to only the firs-t stage of the fiberiæation described, i.e. may be subjected to only that stage of the fiber.ization occurring as a result of the feed of the attenuable material into the zone between the counter-rotating tornadoes developed by the action of guide elements employed with the jet. In this event, the blastr .-i.e., the toratiny blast, and the penetration of the jet into the blast may be dispensed with, thereby simpli~ying the e~uipment set: up~
.~
-8- ~
Although the technique o~ the present invention is applicable to any attenuable material, it i5 particularly adapted to the attenu~ation~o~ thermoplastic materials and especially thermoplastic mineral materials such as glass ~nd similar compositions which are heated to the molten state or the mol~en consistency appropriate for attenuation.
The embodiment illustrated and described hereinafter is particularly appropriate for use in the attenuation of ~lass or similar compositions, and where references are made to glass, unless otherwise indicated by the ~ontext, i~ is to be understood that any appropriate attenuable material may be used.
The invention claimed in the parent application above identi~ied, provides a method for forming fibers from attenuable material, comprising generating a gaseous jet having a substantially laminar Çlow central portion and having at opposite lateral sides a pair of counter-rotating tornadoes of diameter progressively increasing and ultimately merging downstream of the portion of laminaL
flow, and delivering a stream of attenuahle material to the portion of laminar 10w between the tornadoes upstream of the region of merging.
The invention claimed in the parent application may be carried out by an apparatus for forming fibers from attenuable material comprising means for genexating a gaseous flow, means for establishing a pair o spaced counter~rotating :; . . ~ ... ~: , .
3l1;~5~
tornadoes and an interilled1ate la~inar flow area irl the gaseous 10w with the laimillaL fl~w area exposed at one side of the gaseous flow and with the tornadoes increasing in diameter and ultimately merging downstream of the laminar area, and means for delivering a stream of attenuable material into the influence of the gaseous flow in a region along the path thereof in the exposed laminar flow area between the tornadoes.
In accordance with one aspect as claimed in the present application, the invention provides a method for converting molten glass into glass fibers comprising deliv-ering a stream of the molten glass downwardly from ~ supply orifice, establishing a gaseous blast spaced below the glass supply orifice, developing a gaseous jet of smaller cross section than that of the blast directed in a path toward the glass stream between the glass supply orifice and the blast, and deflecting the jet from said path into a patb extended downwardly toward the blast by interposiny a deflector element between the jet and the glass stream, the glass stream being delivered to the deflected jetO
,; : ' In accordance with another aspect o~ the invention ~ :
as claimed herein, there is provided equipment for making fibers from attenuable material comprising supply means for the attenuable material having a delivery orifice posi~
tioned for downward delivery of a stream of the material, ' :., ;, , 5~9 , means for establishing a gaseous blast ~elow the supply means, means for establishins a gaseous jet including an orifice discharging a Jet of smaller cross section than tbat of the blast, and means for deflecting the path of the jet into a path intersecting the path of the blast, the delivery orifice for the attenuable material being positioned to deliver said stre~n to the jet in said de-flected path, the de~lected jet being oE sufficient velo-city to penetrate the blast and develop a zone of interac-tion of the jet and blast in the vicinity of the penetration of the jet.
Equipment is also provided comprising supply means for the attenuable material having a delivery orifice positioned for downward delivery of a stream of the mate-rial, means for establishing a gaseous blast in a position spaced below the supply means, means for establishing a gaseous jet including an orifice discharging a jet of smaller cross section than that of the blast, and jet guiding means comprising a guide element positioned to guide the jet in a path from which the jet approaches and penetrates the blast through the boundary thereof presented toward :
the stream delivery oxifice and thereby develop a zone of interaction of the jet with the blast~ said delivery orifice being positioned with relation to the jet and blast ~o deliver the stream of attenuable material to the influ- ;
ence of the guided jet and thence into said zone of interaction~ ~ -:' ; . -S~ill further, in ar.other aspect, there is provided ., , ', r ~. .
equipment for making ~l~ss f bers from molten glass compris-ing glass supply means having a delivery orifice positioned for downward del.ivery of a stream of molten glass, means for establishing a gaseous blast spaced below the glass delivery orifice, means for establishing a gaseous jet including an orifice discharging a jet of smaller cross section than that of the blast, and jet guiding means com-prising a guide element positioned to guide the jet in at least a portion of a path between the jet orifice and the boundary of the blast pres~nted toward the glass deliv-ery orifice, the jet having kinetic eneryy per unit of volume higher than the blast and penetrating the blast to develop a zone of interaction of the jet with the blast, and the glass delivery orifice being positioned with rela-tion to the jet and the blast so that the stream of molten glass is introduced into the influence of the guided jet and thence into said zone of interaction~ ~ :
The invention as claimed herein also provides equipment for making glass fibers from molten glass com- ~:
prising glass supply means having delivery orifices posi-tioned for downward delivery of streams of molten glass, means for establishing a gaseous blast spaced below the ~:
glass delivery orifices, means for establishing a plural-ity of gaseous jets including orifices discharging jets of smaller cross section than that of the blast, and jet -12- .
~3V5~g ~y guiiding meians comprising a guidi~i element interposed ini part in the path of the ~ett~ind positioned to guide the jets in at least a portion of the path thereof between the jet orifices and the bou~dary of the blast presented toward the glass deIivery orifices, the jets being o~ higher velocity than t~ej blast and penetrating the blast to develo~
zones of interaction of the jets with the blast, the jets being p~sitioned close to each other to provide for inter-action t ~ eof in their guided paths, and the glass delivery orifices being positioned with relation to the jets and the blast so that the streams of molten glass are introdllced into the influence of the guided jets and thence into said zones of interaction.
The apparatus as claimed herein also comprises lS means for establishing a gaseous blast, a series of spaced orifices for directing gaseous jet.s in side-by-sid~ gener~illy parallel paths and peinetrating the blast to de~elop æones of interaction between tihe jets and the blast, means for delivering stre~ms of molten attenuable material ir=ito the influence of said zones of interaction including a supply bushing having a series of delivery orifices for the molten material, gas supply means fo~ the jet orifices comprising separate manifold boxes for different groups of the jet orifices r and means for mounting the manifold boxes for separate adjustrrient movement with respect to the streams ~ -of the molten attenuable material.
' ~
--1~-- ;, ,,. ~ `
, . .
s How the roregoin~.features and advantages are attained will appear more fully from the following descrip-tion referring to the accompanying drawi.ngs which illus~
trate one preferred embodiment of equipment according to S the invention and also which diagrammatically represent significant portions of the acti.on of the jet, blast and of the attenuating operation itself. In the drawings ~
FigurP 1 is an outline overall elevatio~al view with a few parts shown in vertical section showing the general arrangement of the major components of an e~uipment according to the technique of the present invent.ion;
Figure 2 is an enlarged vertical sectional view of the components provided at one of the fiberizin~ centers, this view being taken as indicated by the section line
The present application i5 a di.v.tsion of our copending application Serial No. 290,246, filed November 4, 1977.
Fiber formation from.attenuable material by esta-blishing a pair of counter rotating whirls or tornadoes, known as toration, is disclosed in our Canadian Application No. 196,097. In that known technique, a gaseous blast is generated and a gaseous jet, known as secondary or carrier jet, is also generated, the jet being of smaller cross section than the blast, being directed in a path transverse to the axis of the blast, and having higher kinetic ener~y per unit of volume than the blast so that the jet penetrates the blast. Such a jet penetrating a blast develops a zone of interaction of the jet and blast~
which zone is characterized by the development of a pair of opposit~ly rotating tornadoes between which a zone of :
relatively low pressure occurs at the blast boundary adja~
cent to and downstream of the zone of penetration of the ~-jet into the blast. In this known toration technique t a stream of the attenuable material is delivered to the zone of low pressure, from which the attenuable material en~ers the zone of interaction between the jet and blast and is subjected to the high velocity currents of the whirls or tornadoes, thereby effecting attenuation of the stream and forming the flber.
`, `,,~ ~ ~ . , :
~. .
.
~L~519 ~
As disclosed in the prior application above re-ferred tc~ the stream of attenuable material is delivered or introduced into the zone of interaction by the placement of a discharge orifice for the attenuable material at or substantially at the boundary of the blast. It is a major objective of the present invention to provide for the sep-aration of the discharge orifice for the attenuable material from the boundary of the blast and at the same time to provide for such separation while maintaining stable deliv-ery of the attenuable material into the system. The manner in which this is accomplished will be developed more fully herebelow.
In accordance with one important aspect of the present invention, provision is made for the generation of a pair of counter-rotating whirls or tornadoes, by estab-lishing a gaseous flow or jet and by utilizing certain jet guiding structure or deflector arranged (in the manner more fully described hereinafter) to generate a pair of counter-rotating whirls or tornadoes having therebetween an area of substantially laminar flow also characteriz~d by low pressure with consequent pronounced induction of air. It will be noted that, in accordance with this aspect of the present invention, the pair of counter-rotating tornadoes is generated by guide structure influencing a gaseous flow or jet, rather than by the penetration of ~--a jet into a blast, as in the toration technique disclosed ~;
in the application above identified. The action of the . ~1~1~
deflector not only develops the pair of tornadoes but also provides the substantially ldminar flow low pressure area between the pair of tornadoes, and the present invention contemplates the introduckion or del~very of a stream of attenuable material, for instance~ molten glass, into the influence of the induced air entering the zone or area of laminar flow formed between the pair of counter-rotating tornadoes. This results in introduction of the stream of attenuable material into the laminar flow between the tornadoes and thence into the inEluence of the high velocity currents of the pair of tornadoes, with consequent atten-uation of the stream to form a fiber.
In accordance with another important aspect of the present invention~ the a-ttenuation technique above described, including the generation of the oppositely rotat-ing tornadoes acting on a gaseous jet is used as a first ~-stage of a two-staye attenuation technique, the second stage being effected by delivery oE the jet a~d the atten-uating fiber carried thereby transversely into a blast of larger cross section, the jet still retaining sufficient kinetic energy to penetrate the blast and develop a zone of interaction in accordance with the toration technique ~-describe~ in the above identified applications. This re-sults in in~roduction of the pre]iminarily attenuated fiber into the zone o-f interaction of the jet and the blast, with consequent further attenuation of the fiber.
By the above described operation, a single fiber is formed from a single-stream of the attenuable material, notwithstanding the fact that the stream is subjected to two sequential stages of attenuation/ each of which in-volves the subjection of a stream or fiber to the action of the high velocity currents set up by the two sequential pairs of tornadoes generated in the jet and in the blast.
Employment of the technique according to the invention, has numerous distinctive advantages. In the ln first place, from the foregoing it will be seen that the use of the pair of tornadoes developed by jet guiding means as a first stage of the attenuating operation, serves also as a means for introduction of the attenuating fiber into the zone of interaction between the jet and the blast, i.e. into the torating zone. Thus, this first stage is in effect utilized as a feed or delivery means in relation to the toration operation subsequently carried on in the toration zone between the jet and blast. This use of the ~;
first stage has numerous important advantages. In the first place such use makes it possible for substantial separation of the several components of the system, namely th~ means for generating the blast, the means for generat- ;
ing the jet and the means for introducing or delivering the attenuable material into the system.
' Separation of the components is in turn advan-eageous for a number of reasons including particularly the fact that such separation reduces heat transfer between . .
:
~,1 the three components of the sys~em, in view of which greater flexibility is possible in the maintenance of different temperatures as between the means for generating the blast, the rneans for generating the jet and thé means for sup-plying and admitting the attenuable material. In turn,such reduction in heat transfer between these components makes possible the use of the system for the production of fibers from materials, such as hard glasses, which require relatively high temperatures to bring them to the molten state or consistency appropriate for a~tenuation.
The separation of the components which is made possible according to the present invention, also elimi-nates or reduces the production of unfiberized or improp-erly fiberized particles resulting from sticking of the attenuable material on hot surfaces. In consequence, more uniformly fiberized products are obtainable.
Still further, the employment of the two-stage system of the present invention, in which the first stage serves as a means for feeding the attenuable material into the zone of interaction of the jet and blastJ i.e~ the toration zone, is desirable because it provides a means for stabilizing feed of the attenuable material into the zone of interaction, notwithstanding the substantial separa-tion of the supply means for the attenuable material from th~ boundary of the blast. Indeed, even with quite sub-stantial separation, the feed of the attenuable material ~ ~: , . . . . .
~ 1~;~5~9 i3 stabilized and accurately controlled, which is an impor-tant factor in providing for uniform fiberizing in t~e zone of interaction, i.e. for uniform tora~ion. Because the first stage or Eeeding means utilizes a pair of counter-rotating tornadoes generated in spaced relation by theguiding action of elements positioned to influence the jet, the laminar flow low pressure area between the tor~
nadoes into which the attenuable material is delivered, results in accurate feed of the stream of attenuable mate~
rial from that area into the region between the counter-rotating tornadoes, and this accuracy is maintained even in the event of some misalignment of the supply orifice for the attenuable material with relation to the jet.
' :;, In consequence of this "automatic" compensation ~ ;
for inaccuracies in the point of supply of the attenuable material, hiyh precision machining of certain parts is no longer necessary, for instance parts associated with the feed of a stream of molten glass~ Such high precision of machining is not readily compatible with the very high temperatures encountered in the handling of molten glass, and this is particularly so where very hard glasses or certain other materials such as slags or certain rocks are being fiberized.
,,: ~...
It is also noted that as an alternative, a slot may be employed for admission of the attenuable material in the general manner disclosed in Figures 12 and 12~, L3~5i~
of the prior ~anadian application above re~erred to in which event, supplem2ntary secondary jet9 would be located one beyond each end of the slot.
The technique of the present invention is also of advantage because it may be employed in connection with a wide variety of attenuable materials, includin~ not onl~
various mineral materials as mentioned above, but even certain organic materials which may be attenuable, sùch as polystyrene, polypropylene, polycarbonate and polyamides.
In the two-stage attenuation tech~ique above referred to, the invention also contemplates employment of certain novel interrelated conditions oE operation of -~
the gaseous jet and gaseous blast, providing improved efficiency with respect to power or energy consumption~ ~
Thus, the invention contemplates establishment or a tor-- ;
ating zone of interaction between the jet and blast by employment of lower jet velocities and temperatures than heretofore used in establishing the ~one of interaction between a jet and blast. By employing lower jet tempera-tures (for instance a temperature approximating ambient ;
or room temperature), consumption of energ~ to heat the jet is eliminated and, in addition, the gas of the jet is increased in density. In consequence, the kinetic ener~y level of the jet required for penetration of the jet into the blast is provided at lower jet velociti~s, 51~
thereby effecting further power economies. When employing such lower jet temperatu~es r ~`,t lS, even pos~ible to employ jet velocities well below the vel~city of the blast and still maintain the kinetic energy level of the jet suf-ficiently high to provide the des:ired penetration of thejet into the blast.
The lower jet velocities are still fur~her of advantage in the two-stage attenuation technique herein disclosed because in the first stage of attenuation, in which the st~eam o~ attenuable material is delivered to the jet, the lower jet velocities and temperatures assist in avoiding fragmentation of the stream of attenuable material.
Although, for most purposes, it is conte~.plated according to the technique of the present invention, that the fiberization of the attenuable material be effected in two stayes in the manner generally descxib.d above, it is to be noted that for some purposes the attenuable ;~
material may be subjected to only the firs-t stage of the fiberiæation described, i.e. may be subjected to only that stage of the fiber.ization occurring as a result of the feed of the attenuable material into the zone between the counter-rotating tornadoes developed by the action of guide elements employed with the jet. In this event, the blastr .-i.e., the toratiny blast, and the penetration of the jet into the blast may be dispensed with, thereby simpli~ying the e~uipment set: up~
.~
-8- ~
Although the technique o~ the present invention is applicable to any attenuable material, it i5 particularly adapted to the attenu~ation~o~ thermoplastic materials and especially thermoplastic mineral materials such as glass ~nd similar compositions which are heated to the molten state or the mol~en consistency appropriate for attenuation.
The embodiment illustrated and described hereinafter is particularly appropriate for use in the attenuation of ~lass or similar compositions, and where references are made to glass, unless otherwise indicated by the ~ontext, i~ is to be understood that any appropriate attenuable material may be used.
The invention claimed in the parent application above identi~ied, provides a method for forming fibers from attenuable material, comprising generating a gaseous jet having a substantially laminar Çlow central portion and having at opposite lateral sides a pair of counter-rotating tornadoes of diameter progressively increasing and ultimately merging downstream of the portion of laminaL
flow, and delivering a stream of attenuahle material to the portion of laminar 10w between the tornadoes upstream of the region of merging.
The invention claimed in the parent application may be carried out by an apparatus for forming fibers from attenuable material comprising means for genexating a gaseous flow, means for establishing a pair o spaced counter~rotating :; . . ~ ... ~: , .
3l1;~5~
tornadoes and an interilled1ate la~inar flow area irl the gaseous 10w with the laimillaL fl~w area exposed at one side of the gaseous flow and with the tornadoes increasing in diameter and ultimately merging downstream of the laminar area, and means for delivering a stream of attenuable material into the influence of the gaseous flow in a region along the path thereof in the exposed laminar flow area between the tornadoes.
In accordance with one aspect as claimed in the present application, the invention provides a method for converting molten glass into glass fibers comprising deliv-ering a stream of the molten glass downwardly from ~ supply orifice, establishing a gaseous blast spaced below the glass supply orifice, developing a gaseous jet of smaller cross section than that of the blast directed in a path toward the glass stream between the glass supply orifice and the blast, and deflecting the jet from said path into a patb extended downwardly toward the blast by interposiny a deflector element between the jet and the glass stream, the glass stream being delivered to the deflected jetO
,; : ' In accordance with another aspect o~ the invention ~ :
as claimed herein, there is provided equipment for making fibers from attenuable material comprising supply means for the attenuable material having a delivery orifice posi~
tioned for downward delivery of a stream of the material, ' :., ;, , 5~9 , means for establishing a gaseous blast ~elow the supply means, means for establishins a gaseous jet including an orifice discharging a Jet of smaller cross section than tbat of the blast, and means for deflecting the path of the jet into a path intersecting the path of the blast, the delivery orifice for the attenuable material being positioned to deliver said stre~n to the jet in said de-flected path, the de~lected jet being oE sufficient velo-city to penetrate the blast and develop a zone of interac-tion of the jet and blast in the vicinity of the penetration of the jet.
Equipment is also provided comprising supply means for the attenuable material having a delivery orifice positioned for downward delivery of a stream of the mate-rial, means for establishing a gaseous blast in a position spaced below the supply means, means for establishing a gaseous jet including an orifice discharging a jet of smaller cross section than that of the blast, and jet guiding means comprising a guide element positioned to guide the jet in a path from which the jet approaches and penetrates the blast through the boundary thereof presented toward :
the stream delivery oxifice and thereby develop a zone of interaction of the jet with the blast~ said delivery orifice being positioned with relation to the jet and blast ~o deliver the stream of attenuable material to the influ- ;
ence of the guided jet and thence into said zone of interaction~ ~ -:' ; . -S~ill further, in ar.other aspect, there is provided ., , ', r ~. .
equipment for making ~l~ss f bers from molten glass compris-ing glass supply means having a delivery orifice positioned for downward del.ivery of a stream of molten glass, means for establishing a gaseous blast spaced below the glass delivery orifice, means for establishing a gaseous jet including an orifice discharging a jet of smaller cross section than that of the blast, and jet guiding means com-prising a guide element positioned to guide the jet in at least a portion of a path between the jet orifice and the boundary of the blast pres~nted toward the glass deliv-ery orifice, the jet having kinetic eneryy per unit of volume higher than the blast and penetrating the blast to develop a zone of interaction of the jet with the blast, and the glass delivery orifice being positioned with rela-tion to the jet and the blast so that the stream of molten glass is introduced into the influence of the guided jet and thence into said zone of interaction~ ~ :
The invention as claimed herein also provides equipment for making glass fibers from molten glass com- ~:
prising glass supply means having delivery orifices posi-tioned for downward delivery of streams of molten glass, means for establishing a gaseous blast spaced below the ~:
glass delivery orifices, means for establishing a plural-ity of gaseous jets including orifices discharging jets of smaller cross section than that of the blast, and jet -12- .
~3V5~g ~y guiiding meians comprising a guidi~i element interposed ini part in the path of the ~ett~ind positioned to guide the jets in at least a portion of the path thereof between the jet orifices and the bou~dary of the blast presented toward the glass deIivery orifices, the jets being o~ higher velocity than t~ej blast and penetrating the blast to develo~
zones of interaction of the jets with the blast, the jets being p~sitioned close to each other to provide for inter-action t ~ eof in their guided paths, and the glass delivery orifices being positioned with relation to the jets and the blast so that the streams of molten glass are introdllced into the influence of the guided jets and thence into said zones of interaction.
The apparatus as claimed herein also comprises lS means for establishing a gaseous blast, a series of spaced orifices for directing gaseous jet.s in side-by-sid~ gener~illy parallel paths and peinetrating the blast to de~elop æones of interaction between tihe jets and the blast, means for delivering stre~ms of molten attenuable material ir=ito the influence of said zones of interaction including a supply bushing having a series of delivery orifices for the molten material, gas supply means fo~ the jet orifices comprising separate manifold boxes for different groups of the jet orifices r and means for mounting the manifold boxes for separate adjustrrient movement with respect to the streams ~ -of the molten attenuable material.
' ~
--1~-- ;, ,,. ~ `
, . .
s How the roregoin~.features and advantages are attained will appear more fully from the following descrip-tion referring to the accompanying drawi.ngs which illus~
trate one preferred embodiment of equipment according to S the invention and also which diagrammatically represent significant portions of the acti.on of the jet, blast and of the attenuating operation itself. In the drawings ~
FigurP 1 is an outline overall elevatio~al view with a few parts shown in vertical section showing the general arrangement of the major components of an e~uipment according to the technique of the present invent.ion;
Figure 2 is an enlarged vertical sectional view of the components provided at one of the fiberizin~ centers, this view being taken as indicated by the section line
2-2 on Figure 4;
Figure 3 is a further enlarged ~ragmentary in-verted plan view of some of the jet and glass orifices, this view being taken as indicated by the line 3-3 on Figure 25 Figure 4 is an elevational view of portions of the equipment shown in Figures 1 and 2 and taken from the right of Figure 2;
i9 Figure S is a plan view taken ~enerally ~s in-dicated by the line 5-5 applie~ to ~igu~e 4;
Figure 6 is an enlarged perspective view of a jet manifold box employed in the equipment shown in Figures 1 to 5;
Figure 7 is a perspective diagrammatic view il-lustrating the operation of the method and equipment according to the present invention;
Figure 8 is a cross sectional fragmentary and enlarged view oE the equipment viewed as in Figure 2, and illustrating certain phases of the activity of the blast and jet in ef~ecting attenuation of the glass being delivered from the orifice at the top of the figure;
Figure 9 is a plan view of several jets and of portions of the blast shown in Figure 8, but omitting the glass feed and glass fibers being formed;
Figure 10 is a transverse diagram through por-tions of several adjacent jets, and illustrating directions of rotation o~ certain pairs of the counter-rotating tor- ::
20 : nadoes;
:~;
Figure 11 is a fragmentary sectional view of the major components, particula~ly illustrating certain dimensions to be taken into account in establishing operating conditions in accordance wi-th the preferred practice of the present invention;
. .
.
Figure lla is a fragmentary sectional view show-ing the spacing between a pair of adjacent ~et orifices;
and Figure llb is a transverse sectional view through a portion of the delivery means for the attenuable material.
In connection with the drawings, reference is first made to Figure 1 which shows somewhat schematicall~
a typical overall arrangement ~f equiprnent adapted to carry out the techni~ue of the present invention~ Toward the left in Figure 1 there is shown in outline at 15 a portion of a burner or blast producing structure having an associat-ed noz21e 16 with a discharge aperture 17 of substantial width so as to deliver a blast 1~ with which a plurality of fiberizing centers may be associated. A supply line for a saseous fluid under pressure is indicated in Figure 1 at 19 and this supply line is connected to jet manifold boxes 20 which cooperate in supplying the jet fluid to and through jet orifices, one of which appears at 21. ~ ~-A bushing 22 associated with a forehearth or other appropriate glass supply means indicated at 23 is .
provided with glass orifice means indicated at 24, and the stream of glass is delivered into the flow of the jet ~:
to be described hereinafter and is carried downwardly to the zone of interaction in the blast 18. As will be ex-plained, fiberization occurs in the jet and also in the ' ' ., ,, ,.i ' -16- :
.. ~
blas~, ~r~d as t~,e ~last de~.ivers the fibers toward the right as viewed in ~igure l~;~a fiber blanke~ indicated at 25 is laid down upon ~per~orated traveling conveyor or belt 26, having a suctijon box 2.7 below the upper run of the conv~yor, the box 27 connecting with a suction fan diagrammatically i~ndicated at 28 to assi.st in laying down the desired fiber blanket on the perforated conveyor 26~
Various of the fiberization parts are sho~n in greater detail in Figures 2 to 6 inclusive, to which ref-erence is now made.
The blast and jet structures are advantageouslyadjustably mounted with respect to supporting structure such as diagrammatically indicated at ~9, so that the rela-tive vextical positioning of the blast and the jet ma~
. 15 be altered, and preferably also so thàt the relative posi- ~
tioning of these parts may be adjusted in a direction up- ~;
stream and downstream of the blast 18.
As seen particularly in Figures 4 and 5f the blast nozzle 16 is of substantial width r thereby providing ~;
2~ for a wide blast delivery orifice 17. The bushing 22 for the supply of glass preferably also has substantial dimen~
sion in the direction perpendicular to the plane of Figure 2 in order to provide for the supply of glass to a multi- :
plicity of the glass delivery devices 24 as clearly appears .. .~.~
~L3~5~L9 in Figure ~. Each of the delivery devices 24 has a m.eter-ing orifice 24a and preferably also an elongated reservoir or cup downstream of the metering orifice as indicated at 24b (see particularly Figures 2 and 3). The reservoirs or cups 24b are desirably elongated in the plane of the fiberizing center, i.e. the plane containing the ylass.
supply device 24 and its associated jet orifice 21.
.The jet orifices 21 are provided in the front edge wall of each of a series oE manifold boxes 20, four such boxes being pro~ided in the equipment illustrated, and these boxes are mounted by means of mounting rods, including guide rods 30,30 mounted on the supporting struc-ture 29 and which extend throughout the length of the bush-ing 22 and which pass through apertures 31 (see Figure 2 and Figure 6) on the mounting lugs 32 provided at each ~;
end of each of the jet manifold boxes 20. Thus, the sev- ' eral jet manifold boxes are mounted with freedom for shift-ing movement either to the right or left as viewed in Fig-ures 4 and 5.
Z0 The positions of the jet boxes on the mounting guide rods 30 are determined by means of additional rods -33, 34, 35 and 36, each of which is threaded at its inner end, to cooperate with a threaded aperture in one of the lugs 32 of the guide boxes, one such threaded aperture appearing at 37 in Figure 6. Each of the rods 33 to 36 ,, . , : :
.. ~
r: ~
is provided with CL notchçc3 end 3~ by mean,s of which it may be ~tated, and thesè!adjustable rods are axially fixed, so that rotation thereof :imp~rt~ a lateral adjust-.~ ',r ~ ~
ment or shiftin9 ~o ~ ~ to the associated jet manifold 5 box 20.
~y this arrangement, the relative positions of:
the ~et orifices 21 with respec~ to ~he glass orifice devices 24 may be acljusted~ and this may be used to com pensate for thermal ~xpansion and contractiorl of parts.
Havin~ the jet orifices distribu~ed ~etween cl number of jet manifol~ b~x~s tfour in the embodiment illustrated) provides fo~ substantial alignment of the jet orifice3 with the glass orifices on lirles paral~el.in~ the flow of the blast. Al~hough tha alignment may not be absolute, this is not necess-ary with equipment of the kincl herein illustrated in which the glass stl-eams are delivered into the substantially laminar flow zones ~etween the tornadoes, such as 44b shown in Figure 7, since as above bcought out r delivery of the glass streams into these ~orles re~ults in automatic compensation for sl.ight inaccuracies in the .
~elative positions of the jet and glass orifices.
Each of the boxes 20 is conllected with the jet ~luld supply line 19 by means of a pair of flexible con- ~
nections 39 which permit adjustment of the pos.ition of ~ --the boxes 20 ind~pen~ently of the supply line 19. ~ ~
19-- :
~ ;
As hereinabovelindicated, it is eontemplatec1 according to the present invention that the jets delivered from the jet orifices 21 be su~je~ted to the ~uiding action of certain ele~ents or devices which cooperate with the jets in generating the desired pairs of counter-rotating whirls or tornadoes which are utilized or at leas~ the preliminary attenuation of the streams of attenuable mate-rial and also for purposes of feed of the partially atten-uated filaments into the zone of interaction provided by lD penetration of the jets into the blast~ i.e. into the toration zones. For the purpose of developing the counter~
rotating pairs of tornadoes, the present invention con-templates the utilization of a guiding means, advantageously a common deflector plate 40 associated ~ith a group of the jet orifices. Where the jets are subdivided into groups, and each group associated with a manifold box such as indicated at 20, each such box des~irably carries a deflector plate 40. As seen particuIarly in Figures 7 and 8, the guide or deflector plate is desirably formed as a bent plate, one portion of which overlies and is secured to the jet manifold box and the other portion of ~-which has a free edge 41 lying in a position in the path of flow or core of the jets delivered from the jet orifices 21, advantageously along a line intersecting the axes of the jet orifices.
As is graphically illustrated, particularly in Figure 7, this position of the deflector plate 40 and its edge 41 results in impingement of each of the jets upon 9~3(~
the underside o~ the ~late 4~ ~ith conseguent spreading of the jets. Thus, in Figure 7, the flow of four of the jets originating from orifices a, b, c and d is shown, and it will be seen that as the edge 41 of the plate is - S approached, each of the jets spreads laterally.
It is contemplated according to the invention that the jet orifices 21 be placed sufficiently close to each other and also that the deflector or guiding means be arranged so that upon lateral spreadiny~ the adjacent or adjoining jets will impinge upon each other in the region of the edge 41 of the deflector plate. Preferakly, the adjacent jets impinge upon each other at or clo~e to the ~ree edge 41 of the guide plate 40 as is shown in Figure 7. This results in the generation of pairs of counter-rotating whirls or tornadoes which are indicated in Figure 7 in association with each of the three jets delivered from the oriices a, b and c.
In analyzing he formation of these tornadoes, particular reference is made to those associated with the jet originating from orifice b in Figure ?~ Thus, it will be seen that tornadoes 42b and 43b, are generated and that these two tornadoes have their apices originating substan-tially at the edge 41 of the deflector 40 at opposite sides of the jet at the zone in which the spreading jet impinges upon the adjacent spreadin~ jets delivered from orifices a and o. The tornadoes 42b and 43b are ~ppositely rotating as i5 indicated particularly in Figure 10, and the tor-nadoes enlarge as they progress, until they meet at a poin~
spaced downstream frorn the edge 41 of the deflector. These -5 tornadoes 42b and 43b also have currents in the downstream direction, as will be seen.
Because of the spacing of the apices or points of generation of the tornadoes 42k and 43b and because o~ the progressive enlargement of those tornadoes t a gen-erally tri~ngular zone 44b intervenes between the tornadoes and the edge 41 of the deflector plate, and this triangular zone is of relatively low pressure and is subjected to extensive inflow of induced air, but the flow in this zone is substantially laminar. This is the zone into which the stream of molten glass or other attenuable material is introduced into the system, and because of the character of this triangular laminar ~one the stream of glass is not fragmented but is advanced as a single attenuating stream into the region between the pair of tornadoe~. ;
Attention is now called to the fact that the directions of rotation of the currents in the tornadoes 42b and 43b are opposite, being clockwise for tornado 42b and counter clockwise for tornado 43b as viewed in Figure 7. Thus, the currents in these two tornadoes approach each other at the upper side thereof an~ then flow down~
wardly toward the central or laminar zone 44b.
-2~-... ~
, . . . . . - . .. , " j, The directions of rotation just referred to are further indicated by arrows for the tornadoes 45a and 46a in connection with the corresponding pair of tornadoes associated with the jet delivered from the orifice a.
It will be understood that in the illustration of the jet flow originating from orifice a~ t:he flow has been shown as cut off or sectioned adjacent to the downstream end of the zone of laminar flow 44a, i.e. adjacent to the zone in which the pair of tornadoes have been enlarged and com~
mence the mutual merging which occurs as the jet flow pro-ceeds. With the illustration just referred to, it further clearly appears that the jet flow originating from orifice a not only includes the pair of tornadoes 45a and 46a but also includes another pair of tornadoes 47a and ~8a, the directions of rotation of which are also opposite to each - other, as shown ln Figures 7 and 10, but in this case, the tornado ~7a at the left, as viewed in Figure 7, rotate~
in a counter clockwise direction, whereas the tornado ~8a at the right rotates in the clockwise direction. It will be understood that similar duplicate pairs of tornadoes are generated by and associated with each of the jets.
The origin of generation of the lower pair is somewhat different than the origin of generation of the upper pair ~;~
as will be explained hereinafter with more particular reference to Figure 8.
Still referring to Figure 7, as the flow proceeds from the plane in which the tornadoes are illustrated for the jet delivered from orifice a, all four of the tornadoes ~ ;
''..
~, tend to merge and; reform a more generalized jet flow and this is indicated in Figure 7 by a section 49c, represent-ing a downstream section of the jet Elow originating from orifice c. As will be seen, the whirling motions of the tornadoes are diminishing in intensity and the entire flow, including the laminar flow of the central zone of the jet, intermix with each other in the region indicated at 49c, and thereafter the jet prog~esses downwardly toward the blast which is indicated at 18 in Figure 7 and referred to more fully hereinafter.
In the illustration of Figure 7 it will be under-stood that for the sake of clarity, the showing of the various portions of the jet flow is so~ewhat s~hematic.
For instance, in a zone spaced somewhat downstream of the ;
points of origin, the pairs of tornadoes originating in one jet appear in the figure as being somewhat separated from the pair of tornadoes originating in adjoining jets, whereas, in fact, the tornadoes of adjoining jets would be substantially contiguous.
Turning now to the illustration in Figure 8, it is assum~d that the fiberi~ing center there shown is the center originating at the jet orifice b of Figure 7.
The tornado 43b is also there sho~n/ as is the intervening laminar zone 44b. The lower pair of tornadoes ori~inate in the reg.ion within or under the deflector plate 40, Fig-ure 8 being a sectional view showing only the lower tornado :
. .
48b~ whi~h oriy~nates behin~ Lhe zone ~4b. The direction of rotation o. these lower tornad~es originated as a result of the combined action oE the jet orl the underside of the plate 4U, together with induced air currents joining th~
jet stream, and it is here noted that the currents in the lower pair of tornadoes are of lesser intensîty or velocity than the currents in the upper pair. Moreover~ the direc~
tion of the currents flowing in the tornadoe5 of the upper pair has a dominate influence upon the action of the system when the stream of attenuable material is introduced first into the laminar zone and then into the jet flow downstream of the point where the tornadoes merge.
Because o the jet flow in the laminar zone and in the pairs of tornadoes, particularly the upper pair of each g~oup~ the introduction of the stream of attenuable material, which is indicated in Figure 7 at S for the iber-izing center including the jet o.ifice b, results in the progression oE the stream into the laminar flow of the central zone. This carries the stream into the zone ot high velocity lying between the pairs of tornadoes and, in consequence, the stream is attenuated as is shown in Figure 7. It is found that this attenuation occurs sub-stantially within a planar zone indicated in Figure 7 at P. The action o~ the pairs of tornadoes causes a whipping of the attenuated fiber substantially within the planar zone P, so that this attenuation does not result in pro-jection of the fibers being formed laterally toward the adjoining jets.
.
- . .
Further jet flow causes the jetJ together with the attenuating fiber carried therebyv to penetrate the upper boundary of the blast 18, the je~ flow still retain-ing sufficient kinetic energy t~ effect such penetration of the blast, and thereby initiate a second phase of fi~ber-ization which proceeds or is effected, in accordance wi~h the principles fully explained in the prior Canadian appli-cations referred to above. Indeed, in the region of pene-tration oE the jets into the blast, the flow and velocity of each jet is still sufficiently concentrated near the c~nter of each jet so that each jet acts individually to develop a zone of interaction in the blast. ThuS, from Figure 7 it will be noted that in the zone of interaction~
i.e. in the toration zone, a pair of oppositely rotating whirl5 or tornadoes indicated at TT, are generated, thereby developin~ the curren~s which cause further attenuation of the fiber being formed. The fiber is thereafter carried by the combined flow of the jet and blast to a suitable collection means, for instance a travelling perforated conveyor such as indicated diagrammatically at 26 in Figure 1.
As will be understood, both in the laminar zone adjacent to the edge of the deflector and also as the jet flow progresses downstream, air is inducedJ and this in-duction of air is clearly indicated by arrows applied tothe jet flow in Figure 7. Such induction of air currents is also clearly indicated in Fiyure 8.
~ . - . , .
Ha~.~ing in mind the fo~egoi.ng c3escription of the .
general nature of the e~uipment and operation contemplated according to the present invention/ a~ention is now called to certain permissible variations and ranges of operating conditions which may be employed.
First with regard to the relative positioning of the jet orifices and the guiding or deflecting means, such as the guiding plate 40, it is contemplate~ that the arrangement of the jets and the guiding plate should pro-vide Eor spreading oE the jets so that adjacent jets im-pinge upon each other substantially at the edge of the guide platesO This is the condition illustrated i~ Figure 7 and it will be noted that with this arrangement, the - points of origin or the apices of the upper pairs o~ tor-nadoes are at the edge 41 o~ the guide plate 40.
The jets and the guide plate may be ~rranged so that the jets impinge upon each other at points somewhat ups~ream or downstream of the edge of the guide plate;
but it is preferred that the impingement of adjacent jets upon each other be maintained quite close to, but not necessarily precisely on, the edge of the plate, because in this condition, maximum stability of the tornadoes is attained, with consequent maximum stability oE the inter-vening laminar zone of the jet. In turn, the stability of the laminar zone is important in the stabilization of the glass feed into the system.
~ )5~1~
If the ~oint ~f impingement of adjacent jets is spaced appreciably downstream of the edge of the g~ide plate, the tornadoes become unstable because their apices ori~inate in free space rather than at the edge of the plate. When the apices of the tornadoes originate in ~ree ~pace, they are subject to fluctuations by stray ~as cur~
rents and in consequence tend to shift in position; but if the apices originate at or substantially at the edge of the deflector plate they are l~ss sensitive to stray currents and, indeed appear to "attach" themselves to the edge of the plate in a stable position~
On the other hand, if the adjacent jets impinge upon each othe~ at a point spaced appreciably upstream of the edge of the guide plate, the formation of the tor-nadoes is impaired because the guide plate itself preventsproper formation of the tornadoes.
..
It is also of importance in providing for genera-tion of the upper pair of tornadoes at the edge 41 of the guide plate, that the edge 41 be located at or approximately at the central axis of the jet. If the edge of the guide plate is raised substantially, the de~lection is correspond- -ingly diminished or even eliminated, in which event no tornadoes will be generated~ On the other hand, if the edge of the deflector is located excessively low, for in stance below the lower boundary of the jet, there is a -2~-:~ .
~ 9it, tendency for the tornadoes to diminish ir. th2ir or~aniza-tion and provide only for uniform or parallel flow through-out the entire section of the jetv rather than for the desired higher velocity helical or vortical flow of the tornadoes.
The generation of the tornadoes under the most favorable conditions, i.e. under the conditions in which the apices are "attached'l to the edge of the deflector, produces the most stable tornadoes and thus also the most stable operating conditions with respect to the feed of the glass stream a~d its attenuation in the planar zone P above described.
In connection with the advantages of the tech-nique of the present invention, it is to be noted that 15 - the technique is capable of producing fibers of a wide range of fiber diameter, even fipers of smaller diameter than those produced by the toration technique ~f the Cana-dian applications above identified. However, of special importance and significance is the fact that the technique of the present invention is capable of producing fibers of a given diameter at a substantially hicJher "pull rate"
:
than is possible with the toration technique of tbe Cana-dian application~ ~ully identified above~ The pull rate here referred to is the rate at which the fiber may be formed from a given orifice or supply means for the atten-uab~e material. In accordance with the technigue of the .~
present invention, the pull Lat~ may ~ven be as high as 150 kg/hole per 24 hours. This and other operational fac-- ~ors will be referred to again hereinafter with particular reference to Figures 11, lla and llb and the related tab-ulated information given in the specification herebelow.
As above indicated, the first phase or stage of the attenuation techni~ue of the present invention may if desired be employed independenkly of the second or tora--tion stage, and this first stage, although not capable of producing fibers as fine as those produced when both stages are used, does produce fibers that are fine enough for certain uses and are capable of being produced at a relatively high pull rate~
- Turning now to Pigures 11, lla and llb and also to the information tabulated herebelow, it is first pointed out that the representation of the various components of the system, particularly in Figure 11, is given in a manne~
- to facilitate ex~lanation of the ranges of dimensions and angles, and ~oes not necessarily illustrate the preferred values in all of the ranges.
:, Figure 11 illustrates the three major components, i.e. the means for developing the blast, the means for developing the jet, and the means for introducing the atten-uable material, each of these three means being shown in .
.
, , . . ~,.. -, ~, . ~ . .. .
sec~ion in the same generat manner as in Figures 2 and 8, bUt in Figure 11 symbols or le~ends have been applied - to identify certain dimensi-ons and angLes, all of which are referred to in one or another of the tabulations here-below. Some of these symbols or :Legends appear in Figureslla and llb.
First, with reference to the bushing 22 for the supply of the attenuable material, see the following table:
TABLE I
tmm~
Symbol Preferred Range Value dT 2 1~3 5 lT 1 1~ 5 15 lR 5 R 2 1~ 5 DR 5 1--~ 10 With reference to the ~et supply and the deflec~
tor, sce the fo1lowing table:
' ''` ' -31~ ~
T~
(mm, degree) . Symbol Preferred Range Yalue dJ 2 0.5~ 4 lJ 7 1 ---~
Y Close to lower about 3-~ about 4 J end of range D 4 2 -~ 10 .1JD -. - O _O . O~
JD 45 3S ---~ 55 ~CJB 10 0 ~ 45 JD 3 - 2 ~ 5 LJD 3 2 ~ 5 In connection with the values indicated for it is pointed out that zero value represents the position ::
of the deflector in which the lowermost portion of the ~:
free ed~e of the deflector lies on the axes of the jets, a negative value for 1~D representing a position o~ the deflector above the jet axes~
:: ',;
In connection with the angle identified above ::
as ~ JD~ it is to be noted that downstream of the edge of the deflector, the jet spreads or enlarges, as will be evident from Figures.l, 2 and 8. However, the angle of ~5 this spreading is not the same as the angle represented by the symbol ~ JD~ because the deflector causes the jet to alter its path and also influence the extent to which the jet spreads.
With regard to the blast, note the following table:
TABLE I.~I
(~n) Symbol Preferred Range Value B 10 5 ~ 20 In addition to the foregoing dimensions and angles involved in the three major components of the syst~m, cer-tain interrelationships of those components are also to ~;
be noted, being given in the table just below~
TABLE IV
(mm, degree~
Symbol Preferred Range Value ZJF . 8 3 S 15 : ZJB 17 6~ 30 ~XBJ . _5 -12A - ' ' > +13 ~ ;
XJF 5 3 ~ 8 ~, - .
~ DB 45 35 -- ~ 55 In connection with the symbol X~J~ it will be noted that in the illustration of Figure 11, XBJ is indicated at a negative value, i.e. with the blast nozzle in a position ; :
(in relation to the direction of ~low of the ~last) which :: -is upstream of the position of the jet.
~,;
,;~ , '~:
.. . .:
"' `'I
....... , ., . .. ~ .. . ,...... . , , ,, , " " ,, , ~05~
As in~icated hereinabove, it is contPmplated according to the present invention that the carrier or secondary jets be placed sufficiently closç to each other so tbat they impinge upon each other in order to develop the pairs of tornadoes in each carrier jet. Any convenient number of fiberizing centers may be established/ each cen-ter comprising a delivery device for the attenuable material and an associated jet, and since each carrier jet must impinye upon another jet at each side thereof, it will be seen that the number of jets must include two more than the total number of delivery means for the attenuable m~terial, the two "extra" jets being positioned at the opposite ends of the series of jets.
The number of fiberizing centers may run up to as many as 150, but in a typical installation where glass or some similar thermoplastic material is being fiberi~ed, a bushing having 70 delivery devices or orifices is appro-priate~ In such a case, there would necessarily be 72 jets. -~ ~
::
In connection with the operating conditions, it is first pointed out that the conditions of operating the system according to the present invention will vary in accordance with a number of factors, for example in accordance with the characteristics of the material being - ;~
attenuated.
~g 30~9 As above indicated, the 5yS ~eTn cf the present invention is capable of use in the attenuation of a wide range of attenuable materials. In the attenuation of glass or other inorganic thermoplastic rnaterials, the temperature of the bushing or supply means wi;Ll of course vary accord-ing to the particular material being fiberi%ed. The tempera-ture range for materials of this general type may fall between about 1400 and 1800C. Wiith a typical glass com-position the bushing temperature may approximate 1~80~C.
The pull rate may run from about 20 to 150 kg/hole per 24 hours, typical values being from about 5Q ta about 80 kg/hole per 24 hours.
Certain values with respect to the jet and blast are also of significance~ as indicated in tables just below in which the following symbols are used.
T = Temperature p = Pressure V - Velocity ~ = Density TABLE V -_JET SUPPLY
Symbol Preferred Range Value pJ (bar) 2.5 1 - -~ ~
TJ (~C) 20 ~ 1500 V~ ~m/s) 330 200---~900 ~ 2) (bar) 2.] 0.8~3.5 TABI.E ~ BLAST
Symbol Preferred Range Yalue pB (mbar) 95 30 ~ ~25~
S TB (C) 1450 1350~ 1800 VB ~m/s) 320 200 ~ 550 ~V2~ (bar) 0.2 0.06~0.5 Wi~h regard to the jet and blast, it should be kept in mind that it is contemplated according to the present invention that the deflected jet may be utili~ed alone for attenuation of certain materials, without the employment of the blast in combination with the jet. It is also to be kept in mind that where both the jet and blast are employed, it is contemplated that the jet shall have a cross section smaller than that of the blast and shall penetrate the blast.in order to develop a zone of i~teraction in which the secondary or toration phase of ~:
the attenuation will be effected. For this purpose, the jet must have greater kinetic energy than the blast, per unit o~ volume of the iet and blast in the operational area thereof. The jet may have kinetic energy of from ;~:
1.60 to 60 times that of the blast, a typical ratio being 10 to 1. Thus, in terms of the kinetic enersy values given :~
in Tables V and VI above: ~ 2~J = 10 S~ ) B . ~ ~
;';;
......
-~;
EX~PLE
In equipment of the kind illustrated in Figures l to 6 and having 70 fiberizing centers, a ylass of -the following composition was attenuat:ed.
Si2 ~3.00%
Fe~03 0.30 Al23 2.95 CaO 7~35 MgO 3.lO
Na~O 14.10 K20 0.80 23 5~90 BaO 2.50 (Parts by weight) The bushing temperature was about 1500C and the jet and blast temperature were respectively about 20C
and 1500C. The ratio of the kinetic energy of the jet to the ~last was about lO to 1. The pull rate was 55 kg/hole per 24 hours.
:
The fiber diameter after both stages of atten- ;~
uation averaged about 5 microns.
" . . ..
Figure 3 is a further enlarged ~ragmentary in-verted plan view of some of the jet and glass orifices, this view being taken as indicated by the line 3-3 on Figure 25 Figure 4 is an elevational view of portions of the equipment shown in Figures 1 and 2 and taken from the right of Figure 2;
i9 Figure S is a plan view taken ~enerally ~s in-dicated by the line 5-5 applie~ to ~igu~e 4;
Figure 6 is an enlarged perspective view of a jet manifold box employed in the equipment shown in Figures 1 to 5;
Figure 7 is a perspective diagrammatic view il-lustrating the operation of the method and equipment according to the present invention;
Figure 8 is a cross sectional fragmentary and enlarged view oE the equipment viewed as in Figure 2, and illustrating certain phases of the activity of the blast and jet in ef~ecting attenuation of the glass being delivered from the orifice at the top of the figure;
Figure 9 is a plan view of several jets and of portions of the blast shown in Figure 8, but omitting the glass feed and glass fibers being formed;
Figure 10 is a transverse diagram through por-tions of several adjacent jets, and illustrating directions of rotation o~ certain pairs of the counter-rotating tor- ::
20 : nadoes;
:~;
Figure 11 is a fragmentary sectional view of the major components, particula~ly illustrating certain dimensions to be taken into account in establishing operating conditions in accordance wi-th the preferred practice of the present invention;
. .
.
Figure lla is a fragmentary sectional view show-ing the spacing between a pair of adjacent ~et orifices;
and Figure llb is a transverse sectional view through a portion of the delivery means for the attenuable material.
In connection with the drawings, reference is first made to Figure 1 which shows somewhat schematicall~
a typical overall arrangement ~f equiprnent adapted to carry out the techni~ue of the present invention~ Toward the left in Figure 1 there is shown in outline at 15 a portion of a burner or blast producing structure having an associat-ed noz21e 16 with a discharge aperture 17 of substantial width so as to deliver a blast 1~ with which a plurality of fiberizing centers may be associated. A supply line for a saseous fluid under pressure is indicated in Figure 1 at 19 and this supply line is connected to jet manifold boxes 20 which cooperate in supplying the jet fluid to and through jet orifices, one of which appears at 21. ~ ~-A bushing 22 associated with a forehearth or other appropriate glass supply means indicated at 23 is .
provided with glass orifice means indicated at 24, and the stream of glass is delivered into the flow of the jet ~:
to be described hereinafter and is carried downwardly to the zone of interaction in the blast 18. As will be ex-plained, fiberization occurs in the jet and also in the ' ' ., ,, ,.i ' -16- :
.. ~
blas~, ~r~d as t~,e ~last de~.ivers the fibers toward the right as viewed in ~igure l~;~a fiber blanke~ indicated at 25 is laid down upon ~per~orated traveling conveyor or belt 26, having a suctijon box 2.7 below the upper run of the conv~yor, the box 27 connecting with a suction fan diagrammatically i~ndicated at 28 to assi.st in laying down the desired fiber blanket on the perforated conveyor 26~
Various of the fiberization parts are sho~n in greater detail in Figures 2 to 6 inclusive, to which ref-erence is now made.
The blast and jet structures are advantageouslyadjustably mounted with respect to supporting structure such as diagrammatically indicated at ~9, so that the rela-tive vextical positioning of the blast and the jet ma~
. 15 be altered, and preferably also so thàt the relative posi- ~
tioning of these parts may be adjusted in a direction up- ~;
stream and downstream of the blast 18.
As seen particularly in Figures 4 and 5f the blast nozzle 16 is of substantial width r thereby providing ~;
2~ for a wide blast delivery orifice 17. The bushing 22 for the supply of glass preferably also has substantial dimen~
sion in the direction perpendicular to the plane of Figure 2 in order to provide for the supply of glass to a multi- :
plicity of the glass delivery devices 24 as clearly appears .. .~.~
~L3~5~L9 in Figure ~. Each of the delivery devices 24 has a m.eter-ing orifice 24a and preferably also an elongated reservoir or cup downstream of the metering orifice as indicated at 24b (see particularly Figures 2 and 3). The reservoirs or cups 24b are desirably elongated in the plane of the fiberizing center, i.e. the plane containing the ylass.
supply device 24 and its associated jet orifice 21.
.The jet orifices 21 are provided in the front edge wall of each of a series oE manifold boxes 20, four such boxes being pro~ided in the equipment illustrated, and these boxes are mounted by means of mounting rods, including guide rods 30,30 mounted on the supporting struc-ture 29 and which extend throughout the length of the bush-ing 22 and which pass through apertures 31 (see Figure 2 and Figure 6) on the mounting lugs 32 provided at each ~;
end of each of the jet manifold boxes 20. Thus, the sev- ' eral jet manifold boxes are mounted with freedom for shift-ing movement either to the right or left as viewed in Fig-ures 4 and 5.
Z0 The positions of the jet boxes on the mounting guide rods 30 are determined by means of additional rods -33, 34, 35 and 36, each of which is threaded at its inner end, to cooperate with a threaded aperture in one of the lugs 32 of the guide boxes, one such threaded aperture appearing at 37 in Figure 6. Each of the rods 33 to 36 ,, . , : :
.. ~
r: ~
is provided with CL notchçc3 end 3~ by mean,s of which it may be ~tated, and thesè!adjustable rods are axially fixed, so that rotation thereof :imp~rt~ a lateral adjust-.~ ',r ~ ~
ment or shiftin9 ~o ~ ~ to the associated jet manifold 5 box 20.
~y this arrangement, the relative positions of:
the ~et orifices 21 with respec~ to ~he glass orifice devices 24 may be acljusted~ and this may be used to com pensate for thermal ~xpansion and contractiorl of parts.
Havin~ the jet orifices distribu~ed ~etween cl number of jet manifol~ b~x~s tfour in the embodiment illustrated) provides fo~ substantial alignment of the jet orifice3 with the glass orifices on lirles paral~el.in~ the flow of the blast. Al~hough tha alignment may not be absolute, this is not necess-ary with equipment of the kincl herein illustrated in which the glass stl-eams are delivered into the substantially laminar flow zones ~etween the tornadoes, such as 44b shown in Figure 7, since as above bcought out r delivery of the glass streams into these ~orles re~ults in automatic compensation for sl.ight inaccuracies in the .
~elative positions of the jet and glass orifices.
Each of the boxes 20 is conllected with the jet ~luld supply line 19 by means of a pair of flexible con- ~
nections 39 which permit adjustment of the pos.ition of ~ --the boxes 20 ind~pen~ently of the supply line 19. ~ ~
19-- :
~ ;
As hereinabovelindicated, it is eontemplatec1 according to the present invention that the jets delivered from the jet orifices 21 be su~je~ted to the ~uiding action of certain ele~ents or devices which cooperate with the jets in generating the desired pairs of counter-rotating whirls or tornadoes which are utilized or at leas~ the preliminary attenuation of the streams of attenuable mate-rial and also for purposes of feed of the partially atten-uated filaments into the zone of interaction provided by lD penetration of the jets into the blast~ i.e. into the toration zones. For the purpose of developing the counter~
rotating pairs of tornadoes, the present invention con-templates the utilization of a guiding means, advantageously a common deflector plate 40 associated ~ith a group of the jet orifices. Where the jets are subdivided into groups, and each group associated with a manifold box such as indicated at 20, each such box des~irably carries a deflector plate 40. As seen particuIarly in Figures 7 and 8, the guide or deflector plate is desirably formed as a bent plate, one portion of which overlies and is secured to the jet manifold box and the other portion of ~-which has a free edge 41 lying in a position in the path of flow or core of the jets delivered from the jet orifices 21, advantageously along a line intersecting the axes of the jet orifices.
As is graphically illustrated, particularly in Figure 7, this position of the deflector plate 40 and its edge 41 results in impingement of each of the jets upon 9~3(~
the underside o~ the ~late 4~ ~ith conseguent spreading of the jets. Thus, in Figure 7, the flow of four of the jets originating from orifices a, b, c and d is shown, and it will be seen that as the edge 41 of the plate is - S approached, each of the jets spreads laterally.
It is contemplated according to the invention that the jet orifices 21 be placed sufficiently close to each other and also that the deflector or guiding means be arranged so that upon lateral spreadiny~ the adjacent or adjoining jets will impinge upon each other in the region of the edge 41 of the deflector plate. Preferakly, the adjacent jets impinge upon each other at or clo~e to the ~ree edge 41 of the guide plate 40 as is shown in Figure 7. This results in the generation of pairs of counter-rotating whirls or tornadoes which are indicated in Figure 7 in association with each of the three jets delivered from the oriices a, b and c.
In analyzing he formation of these tornadoes, particular reference is made to those associated with the jet originating from orifice b in Figure ?~ Thus, it will be seen that tornadoes 42b and 43b, are generated and that these two tornadoes have their apices originating substan-tially at the edge 41 of the deflector 40 at opposite sides of the jet at the zone in which the spreading jet impinges upon the adjacent spreadin~ jets delivered from orifices a and o. The tornadoes 42b and 43b are ~ppositely rotating as i5 indicated particularly in Figure 10, and the tor-nadoes enlarge as they progress, until they meet at a poin~
spaced downstream frorn the edge 41 of the deflector. These -5 tornadoes 42b and 43b also have currents in the downstream direction, as will be seen.
Because of the spacing of the apices or points of generation of the tornadoes 42k and 43b and because o~ the progressive enlargement of those tornadoes t a gen-erally tri~ngular zone 44b intervenes between the tornadoes and the edge 41 of the deflector plate, and this triangular zone is of relatively low pressure and is subjected to extensive inflow of induced air, but the flow in this zone is substantially laminar. This is the zone into which the stream of molten glass or other attenuable material is introduced into the system, and because of the character of this triangular laminar ~one the stream of glass is not fragmented but is advanced as a single attenuating stream into the region between the pair of tornadoe~. ;
Attention is now called to the fact that the directions of rotation of the currents in the tornadoes 42b and 43b are opposite, being clockwise for tornado 42b and counter clockwise for tornado 43b as viewed in Figure 7. Thus, the currents in these two tornadoes approach each other at the upper side thereof an~ then flow down~
wardly toward the central or laminar zone 44b.
-2~-... ~
, . . . . . - . .. , " j, The directions of rotation just referred to are further indicated by arrows for the tornadoes 45a and 46a in connection with the corresponding pair of tornadoes associated with the jet delivered from the orifice a.
It will be understood that in the illustration of the jet flow originating from orifice a~ t:he flow has been shown as cut off or sectioned adjacent to the downstream end of the zone of laminar flow 44a, i.e. adjacent to the zone in which the pair of tornadoes have been enlarged and com~
mence the mutual merging which occurs as the jet flow pro-ceeds. With the illustration just referred to, it further clearly appears that the jet flow originating from orifice a not only includes the pair of tornadoes 45a and 46a but also includes another pair of tornadoes 47a and ~8a, the directions of rotation of which are also opposite to each - other, as shown ln Figures 7 and 10, but in this case, the tornado ~7a at the left, as viewed in Figure 7, rotate~
in a counter clockwise direction, whereas the tornado ~8a at the right rotates in the clockwise direction. It will be understood that similar duplicate pairs of tornadoes are generated by and associated with each of the jets.
The origin of generation of the lower pair is somewhat different than the origin of generation of the upper pair ~;~
as will be explained hereinafter with more particular reference to Figure 8.
Still referring to Figure 7, as the flow proceeds from the plane in which the tornadoes are illustrated for the jet delivered from orifice a, all four of the tornadoes ~ ;
''..
~, tend to merge and; reform a more generalized jet flow and this is indicated in Figure 7 by a section 49c, represent-ing a downstream section of the jet Elow originating from orifice c. As will be seen, the whirling motions of the tornadoes are diminishing in intensity and the entire flow, including the laminar flow of the central zone of the jet, intermix with each other in the region indicated at 49c, and thereafter the jet prog~esses downwardly toward the blast which is indicated at 18 in Figure 7 and referred to more fully hereinafter.
In the illustration of Figure 7 it will be under-stood that for the sake of clarity, the showing of the various portions of the jet flow is so~ewhat s~hematic.
For instance, in a zone spaced somewhat downstream of the ;
points of origin, the pairs of tornadoes originating in one jet appear in the figure as being somewhat separated from the pair of tornadoes originating in adjoining jets, whereas, in fact, the tornadoes of adjoining jets would be substantially contiguous.
Turning now to the illustration in Figure 8, it is assum~d that the fiberi~ing center there shown is the center originating at the jet orifice b of Figure 7.
The tornado 43b is also there sho~n/ as is the intervening laminar zone 44b. The lower pair of tornadoes ori~inate in the reg.ion within or under the deflector plate 40, Fig-ure 8 being a sectional view showing only the lower tornado :
. .
48b~ whi~h oriy~nates behin~ Lhe zone ~4b. The direction of rotation o. these lower tornad~es originated as a result of the combined action oE the jet orl the underside of the plate 4U, together with induced air currents joining th~
jet stream, and it is here noted that the currents in the lower pair of tornadoes are of lesser intensîty or velocity than the currents in the upper pair. Moreover~ the direc~
tion of the currents flowing in the tornadoe5 of the upper pair has a dominate influence upon the action of the system when the stream of attenuable material is introduced first into the laminar zone and then into the jet flow downstream of the point where the tornadoes merge.
Because o the jet flow in the laminar zone and in the pairs of tornadoes, particularly the upper pair of each g~oup~ the introduction of the stream of attenuable material, which is indicated in Figure 7 at S for the iber-izing center including the jet o.ifice b, results in the progression oE the stream into the laminar flow of the central zone. This carries the stream into the zone ot high velocity lying between the pairs of tornadoes and, in consequence, the stream is attenuated as is shown in Figure 7. It is found that this attenuation occurs sub-stantially within a planar zone indicated in Figure 7 at P. The action o~ the pairs of tornadoes causes a whipping of the attenuated fiber substantially within the planar zone P, so that this attenuation does not result in pro-jection of the fibers being formed laterally toward the adjoining jets.
.
- . .
Further jet flow causes the jetJ together with the attenuating fiber carried therebyv to penetrate the upper boundary of the blast 18, the je~ flow still retain-ing sufficient kinetic energy t~ effect such penetration of the blast, and thereby initiate a second phase of fi~ber-ization which proceeds or is effected, in accordance wi~h the principles fully explained in the prior Canadian appli-cations referred to above. Indeed, in the region of pene-tration oE the jets into the blast, the flow and velocity of each jet is still sufficiently concentrated near the c~nter of each jet so that each jet acts individually to develop a zone of interaction in the blast. ThuS, from Figure 7 it will be noted that in the zone of interaction~
i.e. in the toration zone, a pair of oppositely rotating whirl5 or tornadoes indicated at TT, are generated, thereby developin~ the curren~s which cause further attenuation of the fiber being formed. The fiber is thereafter carried by the combined flow of the jet and blast to a suitable collection means, for instance a travelling perforated conveyor such as indicated diagrammatically at 26 in Figure 1.
As will be understood, both in the laminar zone adjacent to the edge of the deflector and also as the jet flow progresses downstream, air is inducedJ and this in-duction of air is clearly indicated by arrows applied tothe jet flow in Figure 7. Such induction of air currents is also clearly indicated in Fiyure 8.
~ . - . , .
Ha~.~ing in mind the fo~egoi.ng c3escription of the .
general nature of the e~uipment and operation contemplated according to the present invention/ a~ention is now called to certain permissible variations and ranges of operating conditions which may be employed.
First with regard to the relative positioning of the jet orifices and the guiding or deflecting means, such as the guiding plate 40, it is contemplate~ that the arrangement of the jets and the guiding plate should pro-vide Eor spreading oE the jets so that adjacent jets im-pinge upon each other substantially at the edge of the guide platesO This is the condition illustrated i~ Figure 7 and it will be noted that with this arrangement, the - points of origin or the apices of the upper pairs o~ tor-nadoes are at the edge 41 o~ the guide plate 40.
The jets and the guide plate may be ~rranged so that the jets impinge upon each other at points somewhat ups~ream or downstream of the edge of the guide plate;
but it is preferred that the impingement of adjacent jets upon each other be maintained quite close to, but not necessarily precisely on, the edge of the plate, because in this condition, maximum stability of the tornadoes is attained, with consequent maximum stability oE the inter-vening laminar zone of the jet. In turn, the stability of the laminar zone is important in the stabilization of the glass feed into the system.
~ )5~1~
If the ~oint ~f impingement of adjacent jets is spaced appreciably downstream of the edge of the g~ide plate, the tornadoes become unstable because their apices ori~inate in free space rather than at the edge of the plate. When the apices of the tornadoes originate in ~ree ~pace, they are subject to fluctuations by stray ~as cur~
rents and in consequence tend to shift in position; but if the apices originate at or substantially at the edge of the deflector plate they are l~ss sensitive to stray currents and, indeed appear to "attach" themselves to the edge of the plate in a stable position~
On the other hand, if the adjacent jets impinge upon each othe~ at a point spaced appreciably upstream of the edge of the guide plate, the formation of the tor-nadoes is impaired because the guide plate itself preventsproper formation of the tornadoes.
..
It is also of importance in providing for genera-tion of the upper pair of tornadoes at the edge 41 of the guide plate, that the edge 41 be located at or approximately at the central axis of the jet. If the edge of the guide plate is raised substantially, the de~lection is correspond- -ingly diminished or even eliminated, in which event no tornadoes will be generated~ On the other hand, if the edge of the deflector is located excessively low, for in stance below the lower boundary of the jet, there is a -2~-:~ .
~ 9it, tendency for the tornadoes to diminish ir. th2ir or~aniza-tion and provide only for uniform or parallel flow through-out the entire section of the jetv rather than for the desired higher velocity helical or vortical flow of the tornadoes.
The generation of the tornadoes under the most favorable conditions, i.e. under the conditions in which the apices are "attached'l to the edge of the deflector, produces the most stable tornadoes and thus also the most stable operating conditions with respect to the feed of the glass stream a~d its attenuation in the planar zone P above described.
In connection with the advantages of the tech-nique of the present invention, it is to be noted that 15 - the technique is capable of producing fibers of a wide range of fiber diameter, even fipers of smaller diameter than those produced by the toration technique ~f the Cana-dian applications above identified. However, of special importance and significance is the fact that the technique of the present invention is capable of producing fibers of a given diameter at a substantially hicJher "pull rate"
:
than is possible with the toration technique of tbe Cana-dian application~ ~ully identified above~ The pull rate here referred to is the rate at which the fiber may be formed from a given orifice or supply means for the atten-uab~e material. In accordance with the technigue of the .~
present invention, the pull Lat~ may ~ven be as high as 150 kg/hole per 24 hours. This and other operational fac-- ~ors will be referred to again hereinafter with particular reference to Figures 11, lla and llb and the related tab-ulated information given in the specification herebelow.
As above indicated, the first phase or stage of the attenuation techni~ue of the present invention may if desired be employed independenkly of the second or tora--tion stage, and this first stage, although not capable of producing fibers as fine as those produced when both stages are used, does produce fibers that are fine enough for certain uses and are capable of being produced at a relatively high pull rate~
- Turning now to Pigures 11, lla and llb and also to the information tabulated herebelow, it is first pointed out that the representation of the various components of the system, particularly in Figure 11, is given in a manne~
- to facilitate ex~lanation of the ranges of dimensions and angles, and ~oes not necessarily illustrate the preferred values in all of the ranges.
:, Figure 11 illustrates the three major components, i.e. the means for developing the blast, the means for developing the jet, and the means for introducing the atten-uable material, each of these three means being shown in .
.
, , . . ~,.. -, ~, . ~ . .. .
sec~ion in the same generat manner as in Figures 2 and 8, bUt in Figure 11 symbols or le~ends have been applied - to identify certain dimensi-ons and angLes, all of which are referred to in one or another of the tabulations here-below. Some of these symbols or :Legends appear in Figureslla and llb.
First, with reference to the bushing 22 for the supply of the attenuable material, see the following table:
TABLE I
tmm~
Symbol Preferred Range Value dT 2 1~3 5 lT 1 1~ 5 15 lR 5 R 2 1~ 5 DR 5 1--~ 10 With reference to the ~et supply and the deflec~
tor, sce the fo1lowing table:
' ''` ' -31~ ~
T~
(mm, degree) . Symbol Preferred Range Yalue dJ 2 0.5~ 4 lJ 7 1 ---~
Y Close to lower about 3-~ about 4 J end of range D 4 2 -~ 10 .1JD -. - O _O . O~
JD 45 3S ---~ 55 ~CJB 10 0 ~ 45 JD 3 - 2 ~ 5 LJD 3 2 ~ 5 In connection with the values indicated for it is pointed out that zero value represents the position ::
of the deflector in which the lowermost portion of the ~:
free ed~e of the deflector lies on the axes of the jets, a negative value for 1~D representing a position o~ the deflector above the jet axes~
:: ',;
In connection with the angle identified above ::
as ~ JD~ it is to be noted that downstream of the edge of the deflector, the jet spreads or enlarges, as will be evident from Figures.l, 2 and 8. However, the angle of ~5 this spreading is not the same as the angle represented by the symbol ~ JD~ because the deflector causes the jet to alter its path and also influence the extent to which the jet spreads.
With regard to the blast, note the following table:
TABLE I.~I
(~n) Symbol Preferred Range Value B 10 5 ~ 20 In addition to the foregoing dimensions and angles involved in the three major components of the syst~m, cer-tain interrelationships of those components are also to ~;
be noted, being given in the table just below~
TABLE IV
(mm, degree~
Symbol Preferred Range Value ZJF . 8 3 S 15 : ZJB 17 6~ 30 ~XBJ . _5 -12A - ' ' > +13 ~ ;
XJF 5 3 ~ 8 ~, - .
~ DB 45 35 -- ~ 55 In connection with the symbol X~J~ it will be noted that in the illustration of Figure 11, XBJ is indicated at a negative value, i.e. with the blast nozzle in a position ; :
(in relation to the direction of ~low of the ~last) which :: -is upstream of the position of the jet.
~,;
,;~ , '~:
.. . .:
"' `'I
....... , ., . .. ~ .. . ,...... . , , ,, , " " ,, , ~05~
As in~icated hereinabove, it is contPmplated according to the present invention that the carrier or secondary jets be placed sufficiently closç to each other so tbat they impinge upon each other in order to develop the pairs of tornadoes in each carrier jet. Any convenient number of fiberizing centers may be established/ each cen-ter comprising a delivery device for the attenuable material and an associated jet, and since each carrier jet must impinye upon another jet at each side thereof, it will be seen that the number of jets must include two more than the total number of delivery means for the attenuable m~terial, the two "extra" jets being positioned at the opposite ends of the series of jets.
The number of fiberizing centers may run up to as many as 150, but in a typical installation where glass or some similar thermoplastic material is being fiberi~ed, a bushing having 70 delivery devices or orifices is appro-priate~ In such a case, there would necessarily be 72 jets. -~ ~
::
In connection with the operating conditions, it is first pointed out that the conditions of operating the system according to the present invention will vary in accordance with a number of factors, for example in accordance with the characteristics of the material being - ;~
attenuated.
~g 30~9 As above indicated, the 5yS ~eTn cf the present invention is capable of use in the attenuation of a wide range of attenuable materials. In the attenuation of glass or other inorganic thermoplastic rnaterials, the temperature of the bushing or supply means wi;Ll of course vary accord-ing to the particular material being fiberi%ed. The tempera-ture range for materials of this general type may fall between about 1400 and 1800C. Wiith a typical glass com-position the bushing temperature may approximate 1~80~C.
The pull rate may run from about 20 to 150 kg/hole per 24 hours, typical values being from about 5Q ta about 80 kg/hole per 24 hours.
Certain values with respect to the jet and blast are also of significance~ as indicated in tables just below in which the following symbols are used.
T = Temperature p = Pressure V - Velocity ~ = Density TABLE V -_JET SUPPLY
Symbol Preferred Range Value pJ (bar) 2.5 1 - -~ ~
TJ (~C) 20 ~ 1500 V~ ~m/s) 330 200---~900 ~ 2) (bar) 2.] 0.8~3.5 TABI.E ~ BLAST
Symbol Preferred Range Yalue pB (mbar) 95 30 ~ ~25~
S TB (C) 1450 1350~ 1800 VB ~m/s) 320 200 ~ 550 ~V2~ (bar) 0.2 0.06~0.5 Wi~h regard to the jet and blast, it should be kept in mind that it is contemplated according to the present invention that the deflected jet may be utili~ed alone for attenuation of certain materials, without the employment of the blast in combination with the jet. It is also to be kept in mind that where both the jet and blast are employed, it is contemplated that the jet shall have a cross section smaller than that of the blast and shall penetrate the blast.in order to develop a zone of i~teraction in which the secondary or toration phase of ~:
the attenuation will be effected. For this purpose, the jet must have greater kinetic energy than the blast, per unit o~ volume of the iet and blast in the operational area thereof. The jet may have kinetic energy of from ;~:
1.60 to 60 times that of the blast, a typical ratio being 10 to 1. Thus, in terms of the kinetic enersy values given :~
in Tables V and VI above: ~ 2~J = 10 S~ ) B . ~ ~
;';;
......
-~;
EX~PLE
In equipment of the kind illustrated in Figures l to 6 and having 70 fiberizing centers, a ylass of -the following composition was attenuat:ed.
Si2 ~3.00%
Fe~03 0.30 Al23 2.95 CaO 7~35 MgO 3.lO
Na~O 14.10 K20 0.80 23 5~90 BaO 2.50 (Parts by weight) The bushing temperature was about 1500C and the jet and blast temperature were respectively about 20C
and 1500C. The ratio of the kinetic energy of the jet to the ~last was about lO to 1. The pull rate was 55 kg/hole per 24 hours.
:
The fiber diameter after both stages of atten- ;~
uation averaged about 5 microns.
" . . ..
Claims (11)
1. A method for converting molten glass into glass fibers comprising delivering a stream of the molten glass downwardly from a supply orifice, establishing a gaseous blast spaced below the glass supply orifice, devel-oping a gaseous jet of smaller cross section than that of the blast directed in a path toward the glass stream between the glass supply orifice and the blast, and deflect-ing the jet from said path into a path extended downwardly toward the blast by interposing a deflector element between the jet and the glass stream, the glass stream being deliver-ed to the deflected jet.
2. Equipment for making fibers from attenuable material comprising supply means for the attenuable material having a delivery orifice positioned for downward delivery of a stream of the material, means for establishing a gas-eous blast below the supply means, means for establishing a gaseous jet including an orifice discharging a jet of smaller cross section than that of the blast, and means for deflecting the path of the jet into a path intersecting the path of the blast, the delivery orifice for the atten-uable material being positioned to deliver said stream to the jet in said deflected path, the deflected jet being of sufficient velocity to penetrate the blast and develop a zone of interaction of the jet and blast in the vicinity of the penetration of the jet.
3. Equipment as defined in Claim 2 in which the axis of the jet is initially directed in the same gen-eral direction as the blast.
4. Equipment for making fibers from attenuable material comprising supply means for the attenuable material having a delivery orifice positioned for downward delivery of a stream of the material, means for establishing a gas-eous blast in a position spaced below the supply means, means for establishing a gaseous jet including an orifice discharging a jet of smaller cross section than that of the blast, and jet guiding means comprising a guide element positioned to guide the jet in a path from which the jet approaches and penetrates the blast through the boundary thereof presented toward the stream delivery orifice and thereby develop a zone of interaction of the jet with the blast, said delivery orifice being positioned with relation to the jet and blast to deliver the stream of attenuable material to the influence of the guided jet and thence into said zone of interaction.
5. Equipment as defined in Claim 4 in which the jet orifice is positioned to dishcarge the jet in a direction transverse to and toward the stream of attenuable material and further in which the guide element has an edge interposed in the path of the jet between the jet orifice and the stream of attenuable material delivered from said stream delivery orifice.
6. Equipment for making glass fibers from molten glass comprising glass supply means having a delivery ori-fice positioned for downward delivery of a stream of molten glass, means for establishing a gaseous blast spaced below the glass delivery orifice, means for establishing a gaseous jet including an orifice discharging a jet of smaller cross section than that of the blast, and jet guiding means com-prising a guide element positioned to guide the jet in at least a portion of a path between the jet orifice and the boundary of the blast presented toward the glass deliv-ery orifice, the jet having kinetic energy per unit of volume higher than the blast and penetrating the blast to develop a zone of interaction of the jet with the blast, and the glass delivery orifice being positioned with rela-tion to the jet and the blast so that the stream of molten glass is introduced into the influence of the guided jet and thence into said zone of interaction.
7. Equipment as defined in Claim 6 in which the glass orifice is located in a position which, with respect to the direction of flow of the blast, is down-stream of the jet orifice.
8. Equipment as defined in Claim 6 in which the jet orifice is positioned to discharge the jet in a direction transverse to and toward the stream of glass and further in which the guide element is interposed in part in the path of the jet between the jet orifice and the stream of glass delivered from the glass delivery orifice.
9. Equipment for making glass fibers from molten glass comprising glass supply means having delivery ori-fices positioned for downward delivery of streams of molten glass, means for establishing a gaseous blast spaced below the glass delivery orifices, means for establishing a plurality of gaseous jets including orifices discharging jets of smaller cross section than that of the blast, and jet guiding means comprising a guide element interposed in part in the path of the jet and positioned to guide the jets in at least a portion of the path thereof between the jet orifices and the boundary of the blast presented toward the glass delivery orifices, the jets being of higher velocity than the blast and penetrating the blast to develop zones of interaction of the jets with the blast, the jets being positioned close to each other to provide for inter-action thereof in their guided paths, and the glass delivery orifices being positioned with relation to the jets and the blast so that the streams of molten glass are intro-duced into the influence of the guided jets and thence said zones of interaction.
10. Equipment as defined in Claim 9 and further including gas supply means for the jet orifices comprising separate manifold boxes for different groups of the jet orifices, and means for mounting the manifold boxes for separate adjustment movement with respect to the streams of the molten attenuable material.
11. Apparatus as defined in Claim 10 in which the means for mounting the manifold boxes comprises mechan-ism for adjusting the relative positions of the boxes in a direction transversely of the blast.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA363,656A CA1130519A (en) | 1976-12-16 | 1980-10-30 | Fiber formation by use of high velocity gas blast attenuation |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR76,37884 | 1976-12-16 | ||
| FR7637884A FR2374440A1 (en) | 1976-12-16 | 1976-12-16 | PROCESS AND DEVICE FOR THE MANUFACTURE OF FIBERS FROM STRETCHABLE MATERIALS |
| CA363,656A CA1130519A (en) | 1976-12-16 | 1980-10-30 | Fiber formation by use of high velocity gas blast attenuation |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1130519A true CA1130519A (en) | 1982-08-31 |
Family
ID=25669177
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA363,656A Expired CA1130519A (en) | 1976-12-16 | 1980-10-30 | Fiber formation by use of high velocity gas blast attenuation |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1130519A (en) |
-
1980
- 1980-10-30 CA CA363,656A patent/CA1130519A/en not_active Expired
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| Date | Code | Title | Description |
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| MKEX | Expiry |