CA1122367A - Method and apparatus for forming fibers from gas blast attenuation - Google Patents
Method and apparatus for forming fibers from gas blast attenuationInfo
- Publication number
- CA1122367A CA1122367A CA306,396A CA306396A CA1122367A CA 1122367 A CA1122367 A CA 1122367A CA 306396 A CA306396 A CA 306396A CA 1122367 A CA1122367 A CA 1122367A
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- Canada
- Prior art keywords
- jets
- blast
- pair
- plane
- zone
- Prior art date
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03B—MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03B37/00—Manufacture or treatment of flakes, fibres, or filaments from softened glass, minerals, or slags
- C03B37/01—Manufacture of glass fibres or filaments
- C03B37/06—Manufacture of glass fibres or filaments by blasting or blowing molten glass, e.g. for making staple fibres
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Geochemistry & Mineralogy (AREA)
- Manufacturing & Machinery (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Organic Chemistry (AREA)
- Nonwoven Fabrics (AREA)
- Spinning Methods And Devices For Manufacturing Artificial Fibers (AREA)
- Laminated Bodies (AREA)
- Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)
- Manufacture, Treatment Of Glass Fibers (AREA)
- Preliminary Treatment Of Fibers (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
Gas blast attenuation is disclosed includ-ing the use of a pair of gaseous jets having axes lying in a common plane and directed to impinge upon each other preferably at an acute angle, the attenuable material being introduced into the influence of air induced by one of the jets in the region of impingement of the jets, and the combined jet flow of the two jets carrying the attenuable material into a zone of interaction between the combined jet flow and a larger gaseous blast.
Gas blast attenuation is disclosed includ-ing the use of a pair of gaseous jets having axes lying in a common plane and directed to impinge upon each other preferably at an acute angle, the attenuable material being introduced into the influence of air induced by one of the jets in the region of impingement of the jets, and the combined jet flow of the two jets carrying the attenuable material into a zone of interaction between the combined jet flow and a larger gaseous blast.
Description
3~i'7 BACKGROUND AND OBJECTS
This invention relates to the formation of fibers from attenuable material and while the invention is adapted for use in the forma-tion of fibers from a wide variety of attenuable materials, it is particularly suited to the atten-uation of various thermoplastic materials, especially mineral materials such as glass and similar compositions which are rendered molten by heating. As with the technique of the - prior Canadian application Serial No. 290,246, filed November 4, 1977, the present invention may be employed in connection not only with various mineral materials, but also with certain organic materials which are attenuable, such as polystyrene, polypropylene, polycarbonate and poly-amides. Since the equipment or apparatus is especially useful in the attenuation of glass and similar thermoplastic materials, the following description refers to the use of glass by way of illustration.
Certain techniques for utilizing whirling currents or tornadoes for the attenuation of molten glass have been disclosed by us in prior applications such techniques being identified as toration. For example, Canadian application Serial No. 196,120, filed March 27, 1974, and also the com-panion Canadian application Serial No. 196,097, filed March 27, 1974, disclose development of pairs of counter-rotating tornadoes by directing a gaseous jet into a larger gaseous blast, thereby creating a zone of interaction including pairs of such tornadoes, and into which zone a stream of molten glass is delivered, with resultant attenuation of the glass stream.
3~7 In the equipment illustrated in prior Canadian applications 196,120 and 196,097, the orifice from which the glass stream is delivered to the zone of interaction is located at or adjacent to the boundary of the blast.
In our prior Canadian application Serial No. 245,501, filed February 11, 1976, toration arrangements are disclosed in which the glass orifice is positioned in spaced relation to the boundary of the blast, and in which the glass stream is delivered by gravity to the zone of interaction established by the interaction of a jet and a larger blast.
.
In prior applications Serial No. 290,246 and 265,560 filed November 12, 1976, both the glass orifices and the jet orifices are spaced from the boundary of the blast, and the glass streams are delivered by the action of the jets into zones of interaction of the jets with the blast.
In the applications just mentioned, the glass streams are also subjected to two stages of attenuation, one stage oc-curring in the jet and the other in the blast.
Still further in our Canadian application Serial No. 290,246, the secondary or carrier jet which delivers the glass into the zone of interaction with the blast is caused to develop a stable zone of laminar flow lying between a pair of counter-rotating whirls or tornadoes, and the glass stream is delivered to the laminar zone and thereafter enters the region of the tornadoes of the carrier jet, which latter merge downstream of the carrier jet, but before the carrier jet reaches the principal blast. As is pointed out in our Canadian application Serial No. 290,246, the operation just described results in a two-stage attenuation, 3Çi~
the first stage taking place as the glass stream is advanced into the influence of the tornadoes of the carrier jet, and the secona stage taking place after the carrier jet and the partially attenuated stream enter the zone of inter-action of the carrier jet with the blast.
According to the disclosure of said Canadian appli-cation Serial No. 290,246, the zone of laminar flow and the tornadoes of the carrier jet are developed as a result of deflection of individual carrier jets provided for each fiberizing center, such deflection being effected by the use of a guiding or deflecting element which causes the jet to change its path. As is brought out in said Canaaian application Serial No. 290,246, such deflection of a carrier jet contributes stability of operation, notwithstanding the delivery of the glass to the carrier jet at a point spaced appreciably from the boundary of the principal blast.
The present invention, in common with Canadian application Serial No. 290,246, has as a major objective, the stabilizing of the stream of glass or other attenuable material by development of a zone of laminar flow between tornadoes established in a jet flow system. However the jet flow system of the present invention is somewhat dif-ferent from that of said prior application, but it also provides various of the advantages thereof together with certain other advantages which are distinctive to the tech-nique of the present invention, as is developed hereinafter.
Z3~'7 Various novel combinations of method steps and apparatus components are involved in various aspects of the present invention.
Thus, in accordance with one aspect of the pres-ent invention, instead of employing a structural element or means such as used in the prior art for guiding or -3a-3ti'i' deflecting individual carrier jets for each fiberizing center, the carrier jets are arranged in pairs, one pair for each fiberizing center, the jets of each pair being directed along converging axes lying in a common plane to provide for impingement of the jets on each other in said common plane thereof, thereby causing the combined jet flow of each pair of jets to spread laterally toward opposite sides of the common plane of the jet axes. According to the in-vention, the lateral spreading of the combined jet flow of each pair of jets is limited or obstructed, preferably by positioning the pairs of jets sufficiently close to each other to provide for impingement of the spreading combined jet flow of each pair of jets on the combined jet flow of adjoining pairs of jets. The obstruction of the spreading combined flow of the pairs of jets develops pairs of spaced tornadoes in the jet flow, with zones of laminar flow between the pairs of tornadoes.
In the system of the present invention streams of glass or other attenuable material are fed to the jet flow in the region of the zone of laminar flow from a posi-tion in the common plane of the jet axes but offset to one side of both jets. This results in some attenuation of the glass streams, but in the preferred practice of the invention a gaseous blast is directed in a path intercept-ing the combined jet flow of the pairs of jets, to provide for further attenuation.
In another aspect, the invention consists of using two jets having approximately the same dimensions 11 i~Z367 for each fiberizatioll center. The kinetic energies of these two jets would preferably be substantially equal.
In -the technique of the present invention the tornadoes established in the combined flow of each pair of jets converge downstream of the zone of laminar flow, and the merged jet flow proceeds in a direction to pene-tra-te through the boundary of the principal blast, such penetration creating a zone of interaction also characterized by the generation of a pair of tornadoes according to the toration technique disclosed in the prior Canadian applications identified above.
Thus, each stream of glass is subjected to a pre-liminary gas blast attenuation between the pairs of tornadoes established by the pairs of carrier jets, and the partially attenuated stream is further attenuated in the zone of inter-action of the combined carrier jet flow with the principal blast. In this way two-stage attenuation of a single fiber is effected and long fibers are produced without the fragmen-tation.
In its broadest form therefore, the present invention provides a method for forming a fiber from attenuable material comprising generating a pair ~of gaseous jets of substantially the same cross-sectional shape and area and with axes lying substantially in a common plane and directed to impinge upon each other at an acute angle in the plane, the jets having substantially the same cross-sectional dimensions in directions transverse to and in the plane, and delivering a stream of attenuable material in attenuable condition from a zone lying in the plane and offset toward one side of both of the jets, the stream of attenuable material being delivered into a zone . 30 of gas induced by one of the jets in the region of impingement ~d/~ -5-.....
~1~23~7 of the jets upon each other.
In i-ts broadest form the above method may be carried out by way of apparatus for forming a fiber from attenuable ma-terial comprising means for establishing a pair of gaseous jets with their axes direc-ted in a common plane at an acute angle to each other so that the jets impinge upon each other in the plane, and means for delivering a stream of attenuable material from a source in the plane offset to one side of both of the jets, the material being delivered from the source in a path lying in the plane, and extended into a zone of gas induced by one of the jets in the region of impingement of the jets upon each other.
How the foregoing objects and advantages are obtained, together with others which will occur to those skilled in the art will appear more fully from the following description referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1 is a somewhat diagrammatic elevational view of the major fiber producing and fiber collecting com-sd/~ -5a-3~i7 ponents of a system according to the invention, with certain parts shown in vertical section;
Figure 2 is an enlarged perspective diagrammatic view illustrating the fiberizing action of the equipment shown in Figure l;
Figure 3 is an enlarged vertical sectional view through the components of one fiberizing center in the plane of the jet orifices;
Figure 4 is a fragmentary transverse sectional view taken substantially as indicated by line 4-4 applied to Figure 3;
Figure 5 is a fragmentary sectional view of the major components of the fiberizing system, particularly illustrating certain dimensions to be taken into account in establishing operating conditions in accordance with the preferred practice of the present invention;
Figure 6 is a fragmentary partially sectioned view indicating the relationship between adjacent jet ori-fices; and Figure 7 is a transverse sectional view through a portion of the delivery means for the attenuable material, also indicating certain dimensions to be taken into account.
l~Z3ii7 DETAILED DESCRIPTION~
Referring first to Figure 1, a blast generator or burner is indicated in outline at 8, the generator hav-ing a delivery device 9 from which a blast 10 is discharged.
In the embodiment illustrated this discharge occurs in a generally horizontal direction, but it is to be understood that the discharge may be directed in other directions.
A manifold 11 for compressed gaseous medium such as compressed air is supplied with gas from a supply pipe 13 through a connection 12. As best seen in Figures 2 and 3 the manifold 11 is provided with pairs of jet orifices 14 and 15, the series of such pairs of orifices being indica-ted in Figure 2 by the numerals 14a-15a, 14b-15b, 14c-15c, 14d-15d, and 14e-15e. The jets delivered from each of the pairs of orifices are indicated by the corresponding letters above, and in this connection it is noted that while three pairs of jets appear in the perspective view of Figure 2, only a single pair of jets (a-a) appears in Figures 1 and 3.
As generally represented in Figure 1 the pair of jets at each fiberizing center, for instance jets a-a impinge upon each other in their common plane and produce a combined carrier jet flow indicated at A in Figure 1, in which a stream of attenuable material is subjected to a preliminary stage of attenuation. The combined jet flow proceeds downwardly and penetrates the blast 10 creating a zone of interaction between the jet and the blast which is utilized for a second stage of attenuation.
3~'7 In the arrangement as shown in Figures l and 3 a glass supply means is generally indicated at 16, this means having a bushing 17, and the bushing having a series of spaced glass discharge devices 13 each fed from a meter-ing orifice l9. Glass bulbs or cones G are delivered fromthe devices 18, and from the bulbs, streams of glass S are delivered in a downward direction, one such bulb and stream being included at each of the fiberizing centers.
~he fibers formed from a series of fiberizing centers spaced transversely of the blast lO are deposited upon a foraminous conveyor or belt 20 in the form of a fiber blanket B, as appears in Figure l. This fiber laydown occurs within a chamber defined, for example, by wall structure such as indicated at 21. Suction boxes are desirably pro-vided below the conveyor 20, as indicated at 22, the boxesbeing connected by ducts 23 with one or more suction fans such as diagrammatically indicated at 24.
The attenuating action effected by the equipment as described above can best be explained and analyzed by reference to Figures 2, 3 and 4.
As already indicated above, the action at each fiberizing center is preferably related to the action of the jets or the jet flow in adjoining fiberizing centers.
In Figure 2, the illustration represents the complete action at the fiberizing center corresponding to jets b-b, but represents only a portion of the action occurring at the fiberizing centers of jets a-a and c-_. In Figure 3 the 3tj7 action at the fiberizing center represented by jets a-a is shown on an enlarged scale, and in analyzing the opera-tion, attention is first directed to the fact that imme-diately following the delivery of any gaseous jet from an orifice, the jet induces ambient air. Thus, as shown in Figure 3, each of the jets a comprises a central jet core indicated by the letter i and a surrounding envelope of gases including induced air indicated by the letter i.
This envelope rapidly expands as the jet flow proceeds, and as shown in Figure 3 the jet core remains as a relatively short cone shaped central portion. Such a core has the velocity of the jet as delivered from the orifice, but the surrounding envelope of induced air is of diminished velo-city as the jet flow proceeds. In both Figures 2 and 3 numerous arrows have been applied indicating the induction of air by the jet flow, and, in Figure 3 also by the blast flow.
When employing a pair of jets of substantially the same kinetic energy per unit of volume and preferably also of substantially the same size, with the two jets hav-ing axes lying in a common plane and converging toward each other so that the jets impinge upon each other preferably at an acute angle, the combined flow of the jets downstream of the region of impingement is caused to spread laterally, i.e., is caused to spread in directions transverse to the common plane of the axes of the two jets. It is contemplated according to the invention that the pairs of jets or the planes of the axes thereof be positioned sufficiently close to each other so that the lateral spreading of the combined 3ti7 flow is obstructed by virtue of impingement of the combined flow of one pair of jets upon the laterally spreading combined flow of the adjoining pairs of jets. This impingement of the combined flow of adjoining pairs of jets develops two pairs of miniature tornadoes in each jet flow, with the points of origin or apices of the tornadoes of each pair being positioned in spaced relation toward opposite sides of the common plane of the axes of the jets. When viewed as in Figures 2, 3 and 4, the upper pair of these miniature tornadoes, indicated at tu-tu, have whirling currents circulat-ing or turning in directions toward each other at the upper side of the tornadoes and away from each other at the lower side, as indicated by the direction arrows applied to Figure 4. On the other hand, the lower pair of tornadoes indicated by letters tl turn in the opposite directions, as is indica-ted by the arrows applied to Figure 4.
Between the two pair of tornadoes in the region of impingement of the jets upon each other, a zone L of laminar flow associated with the tornadoes is developed, this zone having high intensity in-flow of induced air, and it is into this laminar flow zone at the side of the ; upper pair of tornadoes that the stream of glass is intro-duced. As clearly appears in Figures 2 and 3, the stream S of the glass is developed from the glass bulb, which bulb or cone is located in a position horizontally offset from the jet delivery device. However, because the glass of the bulb G is in attenuable or flowable condition as released from the delivery device and the stream S of the attenuable glass is deflected from the horizontally offset position 3~i~
of the bulb toward the laminar flow zone L, this deflection occurring as a result of the intense in-flow of induced air, this effect assures delivery oi- the stream of attenu-able material into the laminar zone Indeed, even with some misalignment of the glass delivery device 18 with respect to the pairs of jets, the in-flow of induced air will automatically compensate for such misalignment and bring the glass stream into proper position.
From the above, it will be seen that by develop-ing the pairs of tornadoes with the intervening zone oflaminar flow at each fiberizing center, and by delivering the attenuable material in attenuable condition into the region near said zone, the induced air automatically carries the stream of attenuable material into the zone of laminar flow and automatically compensates for misalignment, thereby providing a highly stable introduction of the attenuable material into the system.
The arrangement as described above and the action of the induced air currents provides for stable introduc-tion of the attenuable material into the system, even wherethe glass delivery devices are appreciably spaced away from the jet delivery devices, which is desirable in order to facilitate maintenance of appropriate temperature control for both the glass delivery devices and the jet delivery devices.
As seen in Figure 2, the pairs of tornadoes tu and tl tend to merge downstream of the laminar zone L, and as the flow progresses downstream the tornadoes tend to 1~f~3~i,7 lose their identity, as is indicatecl (toward the right of Figure 2) by the sectional showing of the two pairs of tor-nadoes originating with the jets c-c. The merged jet flow of each pair of jets then proceeds downward to penetrate the blast 10 as is indicated in Figure 2 for the jet flow originating with the pair of jets b-b, and within the flow of the blast, the jet develops the zone of interaction char-acterized by an additional pair of tornadoes indicated at T, this interaction being identified as toration and fully explained in the Canadian applications 196,120 and 196,097 identified above.
It will also be seen that the plane containing the axes of the jets cuts through the blast in a direction substantially parallel to the direction of the flow of the blast.
Also as shown in Figures 2 and 3, each stream S of glass is subjected to a preliminary attenuation in the jet flow between the zone of laminar flow or point of introduction of the glass, and the point of penetration of the jet into the blast, and the partially attenuated stream is subjected to further attenuation in the zone of interaction of the jet flow with the blast. As indicated in the drawings, these two stages of attenuation are effected without fragmentation of the glass stream, so that each stream produces a single fiber.
3tj7 The action of the jets at each fiberizing center, particularly in the development of the pairs of tornadoes with the intervening zone of laminar flow, is achieved by employment of a pair of jets each of which is preferably of substantially the same kinetic energy per unit of volume;
preferably also, the jets of each pair are of approximately the same cross sectional area and cross sectional shape, but some leeway is permissible with respect to the relation between the cross sectional areas of the two jets of a pair, particularly if the kinetic energy per unit of volume of each jet is substantially the same.
Moreover, each jet need not necessarily have exactly the same cross sectional dimensions in directions transverse to and parallel to the common plane of the axes of the two jets. In addition, these two dimensions need not necessarily be identical for the individual jets of each pair. However, it is preferred that the cross sectional dimensions should be substantially the same for each jet and for the jets of each pair; and further, that the dimensions of the jets of adjoining pairs should be substantially the same, in order to provide uniformity in the development of the pairs of tornadoes with the intervening zones of laminar flow, as the laterally spreading combined jet flow of each pair of jets impinges upon the combined jet flow of adjoining pairs of jets. Uniformity of the jets at each fiberizing center provides uniformity of fiberizing conditions in the toration zones created by the penetration of the jets into the blast.
3~i7 If desired, the jet flow originating with each pair of jets may be utilized for purposes of fiber attenua- -tion, without employment of a blast, although for most pur-poses, and especially where relatively fine fibers are desired, it is preferred to employ not only the preliminary attenua-tion which is effected by the jet flow, but also the addi-tional attenuation which is effected by toration incident to penetration of the jet flow into the blast.
For purposes of penetration of the jet flow into the blast, when the jet flow reaches the blast it should have higher kinetic energy per unit of volume, than the blast.
It is also to be noted that for the purpose of establishing the zone of laminar flow, into which the stream of glass may be introduced without fragmentation, it ic important that the jets be established so that their axes are directed substantially in a common plane and impinge upon each other in said plane preferably at an acute angle, for instance within the range hereinafter identified.
Various other parameters are also desirably ob-served, as indicated herebelow in connection with Figures 5, 6 and 7 and the following tables.
Figure 5 illustrates the three major components of a fiberizing center, i.e., the means for developing the blast, the means for developing the jet, and the means for introducing the attenuable material, each of these three Z3,~i7 means being shown fragmentarily in section in the same gen-eral manner as in Figure 3. In Figure 5 symbols or legends have been applied to identify various parameters, such as dimensions and angles, all of which are referred to in one :~ 5 or another of the tabulations herebelow. Some of these symbols or legends also appear in Figures 6 and 7. The tables give not only the most appropriate ranges for the dimensions and angles, but also include preferred values.
In considering the symbols and legends, reference is first made to the bushing 17 and the devices 18 for the supply of the attenuable material, in connection with which see table I just below.
: TABLE I
(mm) : 15Symbol Preferred Range Value dT 2 l~ 5 T 1 1 ~ 5 lR 5 0 ~ 10 dR 2 1~ 5 R 5 1~ lO
With regard to the glass supply orifice, it is pointed out that the glass or other attenuable material may be supplied to the fiberizing centers either by means of a series of individual supply orifices, or alternatively, the glass or attenuable material may be supplied through a feed slot, which is common to a plurality of the fiberizing 3~'7 centers, in the general manner explained in our prior Cana-dian application 196,097. Since the individual pairs of jets at the individual fiberizing centers create induced air flow currents, tending to draw the streams of attenuable material into the low pressure or laminar flow zones, this tendency, in the case of employment of a common feed slot, serves to subdivide the glass issuing from the slot and form individual streams of glass each one of which enters one of the laminar flow zones. In this case, the axis of each glass cone is automatically positioned in the plane containing the axes of the corresponding pair of jets.
With respect to the jet orifices, it is pointed out that each pair of orifices may be associated with a common manifold or supply device, as is illustrated in the drawings of the present application; but if desired, the . upper and lower jet orifices of the pairs may be associated with separate superimposed manifolds.
With reference to the jet supply, see the f.ollow-ing table:
TABLE II - (JET) (mm, degree) Symbol Preferred Range Value dJl 2 0.5 ~ 4 dJ2 2 0.5 ~ 4 lJ 3 1 ~
JS 5 2 ~ ~ 10 JJ 45 10 ~ -~ 90 JB 45 20 ~ 90 3,~i7 With regard to the blast, note the following table:
TABLE I I I - ( BLAST ) (mm) Symbol Preferred Range Value B 10 5- ~ 20 In addition to the foregoing dimensions and angles involved in the three major components of the system, cer-tain interrelationships of those components are also to be noted, being given in the table just below.
TABLE IV
(mm) Symbol Preferred Range Value 15 ZJF 8 1- ~ 15 ZJB 17 12 ~ 30 XBJ 0 -20 - ~ +5 XJF 5 0~ 8 In connection with the symbol XBJ, it will be noted that in the illustration of Figure 5, XBJ is indica-ted at a negative value, i.e., with the blast nozzle in a position (in relation to the direction of flow of the blast) which is upstream of the position of the point of intersection of the jet axes.
~ Z31~7 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 fiberized, a bushing having 70 delivery devices or orifices is appro-priate.
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 accord-ance with a number of factors, for example in accordance with the characteristics of the material being attenuated.
As above indicated, the system of 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 materials, the temperature of the bushing or supply means will of course vary accord-ing to the particular material being fiberized. The tempera-ture range for materials of this general type may fall be-tween about 1400 and 1800C. With a typical glass composi-tion, the bushing temperature may approximate 1480C.
The pull rate with such a typical glass may run about 20 to 150 kg/hole per 24 hours, typical values being from about 40 to about 60 kg/hole per 24 hours.
Certain values for such a typical glass with re-spect to the jet and blast are also of significance, as indicated in tables just below in which the following sym-bols are used.
--1~--3~i7 T = Temperature P = Pressure V = Velocity = Density , 5 TABLE V - JET SUPPLY
Symbol Preferred Range Value pJ 2.5 1 ~ 15 TJ (C) 20 0 ~ 1500 ; 10 VJ (m/sec) 330 330 ~ 900 V2) (bar) 2.1 0.8 ~ 40 TABLE VI - BLAST
Symbol Preferred Range Value pB (mbar) 95 30 > 250 TB (C) 1450 1350 ~ 1800 VB (m/s) 320 200 ~ 550 V ) (bar) 0.2 0.06 ~ 0.5 It is to be kept in mind that where both the jet and blast are employed, it is contemplated that the flow of the combined jets shall have a width smaller than that of the blast and preferably have a cross section smaller than that of the blast and shall penetrate the blast in order to develop a zone of interaction in which the secon-dary or toration phase of the attenuation will be effected.For this purpose, the combined jet flow must have greater kinetic energy than the blast, per unit of volume in the operational area thereof. A typical ratio of the kinetic 3i.'7 energy of the jet to the blast is 10 to 1. Thus, in terms of the kinetic energy values given in Tables V and VI above:
~V )J 10 ~ V )B
The foregoing technique is advantageous from a number of standpoints in connection with the fiberization of various materials and especially of thermoplastic miner-al compositions such as glass and other similar materials.
Thus, stability of feed is provided, notwithstanding substan-tial separation of the major components of the system, includ-ing substantial separation or interspacing between the glass supply means, the jet device, and the blast generator.
Separation of these components, in turn, makes possible more accurate control of the relative temperatures prevailing in or at the several components, and temperature control is desirable for effective and efficient fiberization.
The technique of the present invention provides for the development of the pairs of tornadoes in the jet flow and thus for stability of feed by the employment of pairs of jets impinging upon each other, and without the necessity for introduction of other mechanical components influencing the jet path or flow. This is desirable be-cause it minimizes structural parts in the vicinity of the glass feed and thus reduces sticking and accumulation of unfiberized glass on such parts. Elimination of structural parts along the path of the jets is also desirable because structural parts necessarily require positioning with great accuracy, and with the employment of pairs of jets in accordance Z3~j17 with the present invention, no problem remains with regard to positioning of mechanical parts along the paths of the jets.
From the foregoing, it will be seen that the fiber-ization technique of the present invention provides a par-ticularly desirable combination of characteristics and advan-tages, including the following.
In the preferred practice of the invention, accord-ing to which the pairs of jets at each fiberizing station are employed for purposes of feed or delivery of the atten-uable material into a toration zone established by the inter-action of the combined jet flow with a gaseous blast, the employment of the pairs of jets at each fiberizing station provides stability in the introduction of the stream of attenuable material into the jet flow and thus also into the toration zone in the blast. Moreover, this stability is achieved while at the same time making possible appre-ciable spacing or separation between the major components of each fiberizing center, i.e., the means for introducing the attenuable material, the means for developing the jets, and the means for developing the gaseous blast. Such separa-tion of the major components of the fiberizing center is important for several reasons and particularly because of the desirability of avoiding excessive heat transfer from one component to another, in view of which the desired or optimum temperature condition may be established and main-tained for each of the three components of the fiberizing ; system.
~23~7 In connection with the foregoing, it is mentioned that it is advantageous to employ jet supply fluid, such as compressed air at a temperature in the neighborhood of room temperature, whereas the source of attenuable material, for instance glass, and also the means for developing the blast, are both desirably maintained at relatively high temperatures. These desired temperature differentials may be effectively established in a system according to the present invention, because the arrangement of the invention permits appreciable separation of the components.
In addition to the foregoing, the arrangement of the present invention achieves the advantages referred to above without the necessity for the employment of struc-tural parts along the path of the individual jets or of the combined jet flow of the pairs of jets provided at each fiberizing center. Thus, lateral spreading of the jet flow is provided by virtue of the impingement of the jets of each pair upon each other; and the obstruction of the spread-ing is effected by positioning the adjoining pairs of jets sufficiently close to each other so that the lateral spread-ing at each fiberizing center results in impingement of the jet flow at each fiberizing center upon the adjoining jets. In this way, the lateral obstruction of the combined jet flow, with the consequent development of the pairs of tornadoes, each having the intervening zone of laminar flow, is accomplished without the necessity for employment of structural parts adjacent to the paths of the jets, and thus without the problems of erosion, thermal deterioration 3~' or the necessity for precise positioning of structural parts, as would necessarily be encountered where structural parts were relied upon for development of the tornadoes zones of the jets.
This invention relates to the formation of fibers from attenuable material and while the invention is adapted for use in the forma-tion of fibers from a wide variety of attenuable materials, it is particularly suited to the atten-uation of various thermoplastic materials, especially mineral materials such as glass and similar compositions which are rendered molten by heating. As with the technique of the - prior Canadian application Serial No. 290,246, filed November 4, 1977, the present invention may be employed in connection not only with various mineral materials, but also with certain organic materials which are attenuable, such as polystyrene, polypropylene, polycarbonate and poly-amides. Since the equipment or apparatus is especially useful in the attenuation of glass and similar thermoplastic materials, the following description refers to the use of glass by way of illustration.
Certain techniques for utilizing whirling currents or tornadoes for the attenuation of molten glass have been disclosed by us in prior applications such techniques being identified as toration. For example, Canadian application Serial No. 196,120, filed March 27, 1974, and also the com-panion Canadian application Serial No. 196,097, filed March 27, 1974, disclose development of pairs of counter-rotating tornadoes by directing a gaseous jet into a larger gaseous blast, thereby creating a zone of interaction including pairs of such tornadoes, and into which zone a stream of molten glass is delivered, with resultant attenuation of the glass stream.
3~7 In the equipment illustrated in prior Canadian applications 196,120 and 196,097, the orifice from which the glass stream is delivered to the zone of interaction is located at or adjacent to the boundary of the blast.
In our prior Canadian application Serial No. 245,501, filed February 11, 1976, toration arrangements are disclosed in which the glass orifice is positioned in spaced relation to the boundary of the blast, and in which the glass stream is delivered by gravity to the zone of interaction established by the interaction of a jet and a larger blast.
.
In prior applications Serial No. 290,246 and 265,560 filed November 12, 1976, both the glass orifices and the jet orifices are spaced from the boundary of the blast, and the glass streams are delivered by the action of the jets into zones of interaction of the jets with the blast.
In the applications just mentioned, the glass streams are also subjected to two stages of attenuation, one stage oc-curring in the jet and the other in the blast.
Still further in our Canadian application Serial No. 290,246, the secondary or carrier jet which delivers the glass into the zone of interaction with the blast is caused to develop a stable zone of laminar flow lying between a pair of counter-rotating whirls or tornadoes, and the glass stream is delivered to the laminar zone and thereafter enters the region of the tornadoes of the carrier jet, which latter merge downstream of the carrier jet, but before the carrier jet reaches the principal blast. As is pointed out in our Canadian application Serial No. 290,246, the operation just described results in a two-stage attenuation, 3Çi~
the first stage taking place as the glass stream is advanced into the influence of the tornadoes of the carrier jet, and the secona stage taking place after the carrier jet and the partially attenuated stream enter the zone of inter-action of the carrier jet with the blast.
According to the disclosure of said Canadian appli-cation Serial No. 290,246, the zone of laminar flow and the tornadoes of the carrier jet are developed as a result of deflection of individual carrier jets provided for each fiberizing center, such deflection being effected by the use of a guiding or deflecting element which causes the jet to change its path. As is brought out in said Canaaian application Serial No. 290,246, such deflection of a carrier jet contributes stability of operation, notwithstanding the delivery of the glass to the carrier jet at a point spaced appreciably from the boundary of the principal blast.
The present invention, in common with Canadian application Serial No. 290,246, has as a major objective, the stabilizing of the stream of glass or other attenuable material by development of a zone of laminar flow between tornadoes established in a jet flow system. However the jet flow system of the present invention is somewhat dif-ferent from that of said prior application, but it also provides various of the advantages thereof together with certain other advantages which are distinctive to the tech-nique of the present invention, as is developed hereinafter.
Z3~'7 Various novel combinations of method steps and apparatus components are involved in various aspects of the present invention.
Thus, in accordance with one aspect of the pres-ent invention, instead of employing a structural element or means such as used in the prior art for guiding or -3a-3ti'i' deflecting individual carrier jets for each fiberizing center, the carrier jets are arranged in pairs, one pair for each fiberizing center, the jets of each pair being directed along converging axes lying in a common plane to provide for impingement of the jets on each other in said common plane thereof, thereby causing the combined jet flow of each pair of jets to spread laterally toward opposite sides of the common plane of the jet axes. According to the in-vention, the lateral spreading of the combined jet flow of each pair of jets is limited or obstructed, preferably by positioning the pairs of jets sufficiently close to each other to provide for impingement of the spreading combined jet flow of each pair of jets on the combined jet flow of adjoining pairs of jets. The obstruction of the spreading combined flow of the pairs of jets develops pairs of spaced tornadoes in the jet flow, with zones of laminar flow between the pairs of tornadoes.
In the system of the present invention streams of glass or other attenuable material are fed to the jet flow in the region of the zone of laminar flow from a posi-tion in the common plane of the jet axes but offset to one side of both jets. This results in some attenuation of the glass streams, but in the preferred practice of the invention a gaseous blast is directed in a path intercept-ing the combined jet flow of the pairs of jets, to provide for further attenuation.
In another aspect, the invention consists of using two jets having approximately the same dimensions 11 i~Z367 for each fiberizatioll center. The kinetic energies of these two jets would preferably be substantially equal.
In -the technique of the present invention the tornadoes established in the combined flow of each pair of jets converge downstream of the zone of laminar flow, and the merged jet flow proceeds in a direction to pene-tra-te through the boundary of the principal blast, such penetration creating a zone of interaction also characterized by the generation of a pair of tornadoes according to the toration technique disclosed in the prior Canadian applications identified above.
Thus, each stream of glass is subjected to a pre-liminary gas blast attenuation between the pairs of tornadoes established by the pairs of carrier jets, and the partially attenuated stream is further attenuated in the zone of inter-action of the combined carrier jet flow with the principal blast. In this way two-stage attenuation of a single fiber is effected and long fibers are produced without the fragmen-tation.
In its broadest form therefore, the present invention provides a method for forming a fiber from attenuable material comprising generating a pair ~of gaseous jets of substantially the same cross-sectional shape and area and with axes lying substantially in a common plane and directed to impinge upon each other at an acute angle in the plane, the jets having substantially the same cross-sectional dimensions in directions transverse to and in the plane, and delivering a stream of attenuable material in attenuable condition from a zone lying in the plane and offset toward one side of both of the jets, the stream of attenuable material being delivered into a zone . 30 of gas induced by one of the jets in the region of impingement ~d/~ -5-.....
~1~23~7 of the jets upon each other.
In i-ts broadest form the above method may be carried out by way of apparatus for forming a fiber from attenuable ma-terial comprising means for establishing a pair of gaseous jets with their axes direc-ted in a common plane at an acute angle to each other so that the jets impinge upon each other in the plane, and means for delivering a stream of attenuable material from a source in the plane offset to one side of both of the jets, the material being delivered from the source in a path lying in the plane, and extended into a zone of gas induced by one of the jets in the region of impingement of the jets upon each other.
How the foregoing objects and advantages are obtained, together with others which will occur to those skilled in the art will appear more fully from the following description referring to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
Figure 1 is a somewhat diagrammatic elevational view of the major fiber producing and fiber collecting com-sd/~ -5a-3~i7 ponents of a system according to the invention, with certain parts shown in vertical section;
Figure 2 is an enlarged perspective diagrammatic view illustrating the fiberizing action of the equipment shown in Figure l;
Figure 3 is an enlarged vertical sectional view through the components of one fiberizing center in the plane of the jet orifices;
Figure 4 is a fragmentary transverse sectional view taken substantially as indicated by line 4-4 applied to Figure 3;
Figure 5 is a fragmentary sectional view of the major components of the fiberizing system, particularly illustrating certain dimensions to be taken into account in establishing operating conditions in accordance with the preferred practice of the present invention;
Figure 6 is a fragmentary partially sectioned view indicating the relationship between adjacent jet ori-fices; and Figure 7 is a transverse sectional view through a portion of the delivery means for the attenuable material, also indicating certain dimensions to be taken into account.
l~Z3ii7 DETAILED DESCRIPTION~
Referring first to Figure 1, a blast generator or burner is indicated in outline at 8, the generator hav-ing a delivery device 9 from which a blast 10 is discharged.
In the embodiment illustrated this discharge occurs in a generally horizontal direction, but it is to be understood that the discharge may be directed in other directions.
A manifold 11 for compressed gaseous medium such as compressed air is supplied with gas from a supply pipe 13 through a connection 12. As best seen in Figures 2 and 3 the manifold 11 is provided with pairs of jet orifices 14 and 15, the series of such pairs of orifices being indica-ted in Figure 2 by the numerals 14a-15a, 14b-15b, 14c-15c, 14d-15d, and 14e-15e. The jets delivered from each of the pairs of orifices are indicated by the corresponding letters above, and in this connection it is noted that while three pairs of jets appear in the perspective view of Figure 2, only a single pair of jets (a-a) appears in Figures 1 and 3.
As generally represented in Figure 1 the pair of jets at each fiberizing center, for instance jets a-a impinge upon each other in their common plane and produce a combined carrier jet flow indicated at A in Figure 1, in which a stream of attenuable material is subjected to a preliminary stage of attenuation. The combined jet flow proceeds downwardly and penetrates the blast 10 creating a zone of interaction between the jet and the blast which is utilized for a second stage of attenuation.
3~'7 In the arrangement as shown in Figures l and 3 a glass supply means is generally indicated at 16, this means having a bushing 17, and the bushing having a series of spaced glass discharge devices 13 each fed from a meter-ing orifice l9. Glass bulbs or cones G are delivered fromthe devices 18, and from the bulbs, streams of glass S are delivered in a downward direction, one such bulb and stream being included at each of the fiberizing centers.
~he fibers formed from a series of fiberizing centers spaced transversely of the blast lO are deposited upon a foraminous conveyor or belt 20 in the form of a fiber blanket B, as appears in Figure l. This fiber laydown occurs within a chamber defined, for example, by wall structure such as indicated at 21. Suction boxes are desirably pro-vided below the conveyor 20, as indicated at 22, the boxesbeing connected by ducts 23 with one or more suction fans such as diagrammatically indicated at 24.
The attenuating action effected by the equipment as described above can best be explained and analyzed by reference to Figures 2, 3 and 4.
As already indicated above, the action at each fiberizing center is preferably related to the action of the jets or the jet flow in adjoining fiberizing centers.
In Figure 2, the illustration represents the complete action at the fiberizing center corresponding to jets b-b, but represents only a portion of the action occurring at the fiberizing centers of jets a-a and c-_. In Figure 3 the 3tj7 action at the fiberizing center represented by jets a-a is shown on an enlarged scale, and in analyzing the opera-tion, attention is first directed to the fact that imme-diately following the delivery of any gaseous jet from an orifice, the jet induces ambient air. Thus, as shown in Figure 3, each of the jets a comprises a central jet core indicated by the letter i and a surrounding envelope of gases including induced air indicated by the letter i.
This envelope rapidly expands as the jet flow proceeds, and as shown in Figure 3 the jet core remains as a relatively short cone shaped central portion. Such a core has the velocity of the jet as delivered from the orifice, but the surrounding envelope of induced air is of diminished velo-city as the jet flow proceeds. In both Figures 2 and 3 numerous arrows have been applied indicating the induction of air by the jet flow, and, in Figure 3 also by the blast flow.
When employing a pair of jets of substantially the same kinetic energy per unit of volume and preferably also of substantially the same size, with the two jets hav-ing axes lying in a common plane and converging toward each other so that the jets impinge upon each other preferably at an acute angle, the combined flow of the jets downstream of the region of impingement is caused to spread laterally, i.e., is caused to spread in directions transverse to the common plane of the axes of the two jets. It is contemplated according to the invention that the pairs of jets or the planes of the axes thereof be positioned sufficiently close to each other so that the lateral spreading of the combined 3ti7 flow is obstructed by virtue of impingement of the combined flow of one pair of jets upon the laterally spreading combined flow of the adjoining pairs of jets. This impingement of the combined flow of adjoining pairs of jets develops two pairs of miniature tornadoes in each jet flow, with the points of origin or apices of the tornadoes of each pair being positioned in spaced relation toward opposite sides of the common plane of the axes of the jets. When viewed as in Figures 2, 3 and 4, the upper pair of these miniature tornadoes, indicated at tu-tu, have whirling currents circulat-ing or turning in directions toward each other at the upper side of the tornadoes and away from each other at the lower side, as indicated by the direction arrows applied to Figure 4. On the other hand, the lower pair of tornadoes indicated by letters tl turn in the opposite directions, as is indica-ted by the arrows applied to Figure 4.
Between the two pair of tornadoes in the region of impingement of the jets upon each other, a zone L of laminar flow associated with the tornadoes is developed, this zone having high intensity in-flow of induced air, and it is into this laminar flow zone at the side of the ; upper pair of tornadoes that the stream of glass is intro-duced. As clearly appears in Figures 2 and 3, the stream S of the glass is developed from the glass bulb, which bulb or cone is located in a position horizontally offset from the jet delivery device. However, because the glass of the bulb G is in attenuable or flowable condition as released from the delivery device and the stream S of the attenuable glass is deflected from the horizontally offset position 3~i~
of the bulb toward the laminar flow zone L, this deflection occurring as a result of the intense in-flow of induced air, this effect assures delivery oi- the stream of attenu-able material into the laminar zone Indeed, even with some misalignment of the glass delivery device 18 with respect to the pairs of jets, the in-flow of induced air will automatically compensate for such misalignment and bring the glass stream into proper position.
From the above, it will be seen that by develop-ing the pairs of tornadoes with the intervening zone oflaminar flow at each fiberizing center, and by delivering the attenuable material in attenuable condition into the region near said zone, the induced air automatically carries the stream of attenuable material into the zone of laminar flow and automatically compensates for misalignment, thereby providing a highly stable introduction of the attenuable material into the system.
The arrangement as described above and the action of the induced air currents provides for stable introduc-tion of the attenuable material into the system, even wherethe glass delivery devices are appreciably spaced away from the jet delivery devices, which is desirable in order to facilitate maintenance of appropriate temperature control for both the glass delivery devices and the jet delivery devices.
As seen in Figure 2, the pairs of tornadoes tu and tl tend to merge downstream of the laminar zone L, and as the flow progresses downstream the tornadoes tend to 1~f~3~i,7 lose their identity, as is indicatecl (toward the right of Figure 2) by the sectional showing of the two pairs of tor-nadoes originating with the jets c-c. The merged jet flow of each pair of jets then proceeds downward to penetrate the blast 10 as is indicated in Figure 2 for the jet flow originating with the pair of jets b-b, and within the flow of the blast, the jet develops the zone of interaction char-acterized by an additional pair of tornadoes indicated at T, this interaction being identified as toration and fully explained in the Canadian applications 196,120 and 196,097 identified above.
It will also be seen that the plane containing the axes of the jets cuts through the blast in a direction substantially parallel to the direction of the flow of the blast.
Also as shown in Figures 2 and 3, each stream S of glass is subjected to a preliminary attenuation in the jet flow between the zone of laminar flow or point of introduction of the glass, and the point of penetration of the jet into the blast, and the partially attenuated stream is subjected to further attenuation in the zone of interaction of the jet flow with the blast. As indicated in the drawings, these two stages of attenuation are effected without fragmentation of the glass stream, so that each stream produces a single fiber.
3tj7 The action of the jets at each fiberizing center, particularly in the development of the pairs of tornadoes with the intervening zone of laminar flow, is achieved by employment of a pair of jets each of which is preferably of substantially the same kinetic energy per unit of volume;
preferably also, the jets of each pair are of approximately the same cross sectional area and cross sectional shape, but some leeway is permissible with respect to the relation between the cross sectional areas of the two jets of a pair, particularly if the kinetic energy per unit of volume of each jet is substantially the same.
Moreover, each jet need not necessarily have exactly the same cross sectional dimensions in directions transverse to and parallel to the common plane of the axes of the two jets. In addition, these two dimensions need not necessarily be identical for the individual jets of each pair. However, it is preferred that the cross sectional dimensions should be substantially the same for each jet and for the jets of each pair; and further, that the dimensions of the jets of adjoining pairs should be substantially the same, in order to provide uniformity in the development of the pairs of tornadoes with the intervening zones of laminar flow, as the laterally spreading combined jet flow of each pair of jets impinges upon the combined jet flow of adjoining pairs of jets. Uniformity of the jets at each fiberizing center provides uniformity of fiberizing conditions in the toration zones created by the penetration of the jets into the blast.
3~i7 If desired, the jet flow originating with each pair of jets may be utilized for purposes of fiber attenua- -tion, without employment of a blast, although for most pur-poses, and especially where relatively fine fibers are desired, it is preferred to employ not only the preliminary attenua-tion which is effected by the jet flow, but also the addi-tional attenuation which is effected by toration incident to penetration of the jet flow into the blast.
For purposes of penetration of the jet flow into the blast, when the jet flow reaches the blast it should have higher kinetic energy per unit of volume, than the blast.
It is also to be noted that for the purpose of establishing the zone of laminar flow, into which the stream of glass may be introduced without fragmentation, it ic important that the jets be established so that their axes are directed substantially in a common plane and impinge upon each other in said plane preferably at an acute angle, for instance within the range hereinafter identified.
Various other parameters are also desirably ob-served, as indicated herebelow in connection with Figures 5, 6 and 7 and the following tables.
Figure 5 illustrates the three major components of a fiberizing center, i.e., the means for developing the blast, the means for developing the jet, and the means for introducing the attenuable material, each of these three Z3,~i7 means being shown fragmentarily in section in the same gen-eral manner as in Figure 3. In Figure 5 symbols or legends have been applied to identify various parameters, such as dimensions and angles, all of which are referred to in one :~ 5 or another of the tabulations herebelow. Some of these symbols or legends also appear in Figures 6 and 7. The tables give not only the most appropriate ranges for the dimensions and angles, but also include preferred values.
In considering the symbols and legends, reference is first made to the bushing 17 and the devices 18 for the supply of the attenuable material, in connection with which see table I just below.
: TABLE I
(mm) : 15Symbol Preferred Range Value dT 2 l~ 5 T 1 1 ~ 5 lR 5 0 ~ 10 dR 2 1~ 5 R 5 1~ lO
With regard to the glass supply orifice, it is pointed out that the glass or other attenuable material may be supplied to the fiberizing centers either by means of a series of individual supply orifices, or alternatively, the glass or attenuable material may be supplied through a feed slot, which is common to a plurality of the fiberizing 3~'7 centers, in the general manner explained in our prior Cana-dian application 196,097. Since the individual pairs of jets at the individual fiberizing centers create induced air flow currents, tending to draw the streams of attenuable material into the low pressure or laminar flow zones, this tendency, in the case of employment of a common feed slot, serves to subdivide the glass issuing from the slot and form individual streams of glass each one of which enters one of the laminar flow zones. In this case, the axis of each glass cone is automatically positioned in the plane containing the axes of the corresponding pair of jets.
With respect to the jet orifices, it is pointed out that each pair of orifices may be associated with a common manifold or supply device, as is illustrated in the drawings of the present application; but if desired, the . upper and lower jet orifices of the pairs may be associated with separate superimposed manifolds.
With reference to the jet supply, see the f.ollow-ing table:
TABLE II - (JET) (mm, degree) Symbol Preferred Range Value dJl 2 0.5 ~ 4 dJ2 2 0.5 ~ 4 lJ 3 1 ~
JS 5 2 ~ ~ 10 JJ 45 10 ~ -~ 90 JB 45 20 ~ 90 3,~i7 With regard to the blast, note the following table:
TABLE I I I - ( BLAST ) (mm) Symbol Preferred Range Value B 10 5- ~ 20 In addition to the foregoing dimensions and angles involved in the three major components of the system, cer-tain interrelationships of those components are also to be noted, being given in the table just below.
TABLE IV
(mm) Symbol Preferred Range Value 15 ZJF 8 1- ~ 15 ZJB 17 12 ~ 30 XBJ 0 -20 - ~ +5 XJF 5 0~ 8 In connection with the symbol XBJ, it will be noted that in the illustration of Figure 5, XBJ is indica-ted at a negative value, i.e., with the blast nozzle in a position (in relation to the direction of flow of the blast) which is upstream of the position of the point of intersection of the jet axes.
~ Z31~7 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 fiberized, a bushing having 70 delivery devices or orifices is appro-priate.
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 accord-ance with a number of factors, for example in accordance with the characteristics of the material being attenuated.
As above indicated, the system of 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 materials, the temperature of the bushing or supply means will of course vary accord-ing to the particular material being fiberized. The tempera-ture range for materials of this general type may fall be-tween about 1400 and 1800C. With a typical glass composi-tion, the bushing temperature may approximate 1480C.
The pull rate with such a typical glass may run about 20 to 150 kg/hole per 24 hours, typical values being from about 40 to about 60 kg/hole per 24 hours.
Certain values for such a typical glass with re-spect to the jet and blast are also of significance, as indicated in tables just below in which the following sym-bols are used.
--1~--3~i7 T = Temperature P = Pressure V = Velocity = Density , 5 TABLE V - JET SUPPLY
Symbol Preferred Range Value pJ 2.5 1 ~ 15 TJ (C) 20 0 ~ 1500 ; 10 VJ (m/sec) 330 330 ~ 900 V2) (bar) 2.1 0.8 ~ 40 TABLE VI - BLAST
Symbol Preferred Range Value pB (mbar) 95 30 > 250 TB (C) 1450 1350 ~ 1800 VB (m/s) 320 200 ~ 550 V ) (bar) 0.2 0.06 ~ 0.5 It is to be kept in mind that where both the jet and blast are employed, it is contemplated that the flow of the combined jets shall have a width smaller than that of the blast and preferably have a cross section smaller than that of the blast and shall penetrate the blast in order to develop a zone of interaction in which the secon-dary or toration phase of the attenuation will be effected.For this purpose, the combined jet flow must have greater kinetic energy than the blast, per unit of volume in the operational area thereof. A typical ratio of the kinetic 3i.'7 energy of the jet to the blast is 10 to 1. Thus, in terms of the kinetic energy values given in Tables V and VI above:
~V )J 10 ~ V )B
The foregoing technique is advantageous from a number of standpoints in connection with the fiberization of various materials and especially of thermoplastic miner-al compositions such as glass and other similar materials.
Thus, stability of feed is provided, notwithstanding substan-tial separation of the major components of the system, includ-ing substantial separation or interspacing between the glass supply means, the jet device, and the blast generator.
Separation of these components, in turn, makes possible more accurate control of the relative temperatures prevailing in or at the several components, and temperature control is desirable for effective and efficient fiberization.
The technique of the present invention provides for the development of the pairs of tornadoes in the jet flow and thus for stability of feed by the employment of pairs of jets impinging upon each other, and without the necessity for introduction of other mechanical components influencing the jet path or flow. This is desirable be-cause it minimizes structural parts in the vicinity of the glass feed and thus reduces sticking and accumulation of unfiberized glass on such parts. Elimination of structural parts along the path of the jets is also desirable because structural parts necessarily require positioning with great accuracy, and with the employment of pairs of jets in accordance Z3~j17 with the present invention, no problem remains with regard to positioning of mechanical parts along the paths of the jets.
From the foregoing, it will be seen that the fiber-ization technique of the present invention provides a par-ticularly desirable combination of characteristics and advan-tages, including the following.
In the preferred practice of the invention, accord-ing to which the pairs of jets at each fiberizing station are employed for purposes of feed or delivery of the atten-uable material into a toration zone established by the inter-action of the combined jet flow with a gaseous blast, the employment of the pairs of jets at each fiberizing station provides stability in the introduction of the stream of attenuable material into the jet flow and thus also into the toration zone in the blast. Moreover, this stability is achieved while at the same time making possible appre-ciable spacing or separation between the major components of each fiberizing center, i.e., the means for introducing the attenuable material, the means for developing the jets, and the means for developing the gaseous blast. Such separa-tion of the major components of the fiberizing center is important for several reasons and particularly because of the desirability of avoiding excessive heat transfer from one component to another, in view of which the desired or optimum temperature condition may be established and main-tained for each of the three components of the fiberizing ; system.
~23~7 In connection with the foregoing, it is mentioned that it is advantageous to employ jet supply fluid, such as compressed air at a temperature in the neighborhood of room temperature, whereas the source of attenuable material, for instance glass, and also the means for developing the blast, are both desirably maintained at relatively high temperatures. These desired temperature differentials may be effectively established in a system according to the present invention, because the arrangement of the invention permits appreciable separation of the components.
In addition to the foregoing, the arrangement of the present invention achieves the advantages referred to above without the necessity for the employment of struc-tural parts along the path of the individual jets or of the combined jet flow of the pairs of jets provided at each fiberizing center. Thus, lateral spreading of the jet flow is provided by virtue of the impingement of the jets of each pair upon each other; and the obstruction of the spread-ing is effected by positioning the adjoining pairs of jets sufficiently close to each other so that the lateral spread-ing at each fiberizing center results in impingement of the jet flow at each fiberizing center upon the adjoining jets. In this way, the lateral obstruction of the combined jet flow, with the consequent development of the pairs of tornadoes, each having the intervening zone of laminar flow, is accomplished without the necessity for employment of structural parts adjacent to the paths of the jets, and thus without the problems of erosion, thermal deterioration 3~' or the necessity for precise positioning of structural parts, as would necessarily be encountered where structural parts were relied upon for development of the tornadoes zones of the jets.
Claims (25)
1. A method for forming a fiber from attenuable material, comprising directing a pair of gaseous jets at an acute angle to each other along converging axes lying substantially in a common plane to provide for impingement of the jets on each other with consequent lateral spread-ing of the combined jet flow, the jets having substantially the same cross-sectional dimensions in directions transverse to and in said plane, obstructing the lateral spreading of the combined jet flow and thereby generating a pair of tornadoes in the edge portions of the combined flow of the jets with the tornadoes spaced from each other toward oppo-site sides of said common plane and having a zone of induced air and laminar flow intervening therebetween, and deliver-ing a stream of attenuable material in attenuable condition from a zone lying in said plane and offset toward one side of both of said jets into the zone of induced air and laminar flow from a region lying in said common plane and offset toward one side of both jets of the pair.
2. A method as defined in Claim 1 in which the jets of the pair have substantially the same kinetic energy per unit of volume.
3. A method as defined in Claim 2 in which the jets have substantially the same cross-sectional area.
4. A method as defined in Claim 1 and further including generating a gaseous blast directed in a path intercepting the combined jet flow, the combined jet flow having a cross-sectional dimension smaller than that of the blast in a direction transverse the blast, and the com-bined jet flow having kinetic energy per unit of volume greater than that of the blast so that the combined jet flow penetrates the blast and carries the attenuable mate-railway into the zone of interaction between the jet and blast.
5. A method for forming a fiber from attenuable material, comprising directing a pair of gaseous jets at an acute angle to each other along converging axes lying substantially in a common plane to provide for impingement of the jets on each other with consequent lateral spreading of the combined jet flow, the jets having substantially the same cross-sectional dimensions in directions trans-verse to and in said plane, generating a pair of tornadoes in the edge portions of the combined flow of the jets, the tornadoes being spaced from each other toward opposite sides of said common plane and having a zone of laminar flow inter-vening between the tornadoes, generating a gaseous blast directed in a path transverse to and intercepting the com-bined jet flow, the combined jet flow having a cross-sectional dimension smaller than that of the blast in a direction transverse to the blast but having kinetic energy per unit of volume greater than that of the blast with consequent penetration of the jet into the blast, and delivering a stream of attenuable material in attenuable condition into said zone of laminar flow from a region lying in said common plane and offset toward one side of both jets of the pair.
6. A method for forming a fiber from attenuable material, comprising directing a pair of gaseous jets at an acute angle to each other along converging axes lying substantially in a common plane to provide for impingement of the jets on each other with consequent lateral spreading of the combined jet flow, the jets having substantially the same cross-sectional dimensions in directions transverse to and in said plane, generating a pair of tornadoes in the edge portions of the combined flow of the jets, the tornadoes being spaced from each other toward opposite sides of said common plane and having a zone of laminar flow inter-vening between the tornadoes, and delivering a stream of attenuable material in attenuable condition into the zone of laminar flow from a region lying in said common plane and offset toward one side of both jets of the pair.
7. A method as defined in Claim 6 in which the gaseous jets of each pair have substantially the same kinetic energy per unit of volume.
8. A method as defined in Claim 6 in which the angle included between the axes of the jets of each pair is between 10° and 90°.
9. A method as defined in Claim 6 in which the jets of each pair are of substantially the same cross-sec-tional size and shape.
10. A method for forming a fiber from attenuable material comprising generating a pair of gaseous jets of substantially the same cross-sectional shape and area and with axes lying substantially in a common plane and directed to impinge upon each other at an acute angle in said plane, the jets having substantially the same cross-sectional dimen-sions in directions transverse to and in said plane, and delivering a stream of attenuable material in attenuable condition from a zone lying in said plane and offset toward one side of both of said jets, the stream of attenuable material being delivered into a zone of gas induced by one of the jets in the region of impingement of the jets upon each other.
11. A method for forming fibers from attenuable material, comprising generating a gaseous blast directed in a predetermined path, generating a plurality of pairs of gaseous jets, the jets of each pair being directed at an acute angle to each other along converging axes lying substantially in a common plane to provide for impingement of the jets of each pair on each other with consequent lat-eral spreading of the combined jet flow of each pair of jets, the jets of each pair having substantially the same cross-sectional dimensions in directions transverse to and in said plane, the pairs of jets being positioned in spaced side-by-side relation with the pairs sufficiently close to each other to provide for lateral impingement of the combined flow of each pair of jets upon the combined flow of adjoining pairs of jets thereby providing for development of pairs of tornadoes in the combined flow of each pair of jets, with a zone of laminar flow intervening between the pairs of tornadoes, and the pairs of jets being positioned so that the combined flow thereof is directed transversely into the blast, the combined jet flow of each pair of jets having greater kinetic energy per unit of volume than that of the blast to provide for penetration of the combined flow of each pair of jets into the blast, and delivering a stream of attenuable material in attenuable condition from a zone lying in said plane and offset toward one side of both jets of at least one of the pairs of jets into the zone of laminar flow of said at least one of the pairs of jets.
12. A method for forming a fiber from attenuable material comprising generating a gaseous blast directed in a predetermined path, generating a pair of gaseous jets of substantially the same cross-sectional dimensions in directions transverse to and in a common plane and with their axes lying substantially in said common plane and and directed to impinge upon each other. at. an acute angle in said plane and merge in a path extended transverse to the path of the blast, the merged jet flow being of smaller, cross-sectional area and of greater kinetic energy per unit of volume than the blast and the merged jet flow penetrating the blast and creating a zone of interaction which the blast, and delivering a stream of attenuable material in attenua-ble condition from a zone lying in the plane of the jets and offset toward one side of both of said jets, the stream of attenuable material being delivered into a zone of gas induced by one of the jets in the region of impingement of the jets upon each other and being carried by the merged jet flow into the zone of interaction in the blast.
13. A method for forming a fiber from attenuable material comprising generating a gaseous blast directed in a Predetermined path, generating a pair of gaseous jets each of substantially smaller width than the blast and with their axes lying substantially in a common plane and directed to impinge upon each other at an acute angle in said plane and merge in a path extended transverse to the path of the blast, the jets having substantially the same cross-sectional dimensions in directions transverse to and in said plane, the merged jet flow being of smaller width and of greater kinetic energy per unit of volume than the blast and the merged jet flow penetrating the blast, and creating a zone of interaction with the blast, and delivering a stream of attenuable material in attenuable condition from a zone lying in the plane of the jets and offset toward one side of both of said jets, the stream of attenuable material being delivered into a zone of gas induced by one of the jets in the region of impingement of the jets upon each other and being carried by the merged jet flow into the zone of interaction in the blast.
14. A method as defined in Claim 13 in which said common plane of the jets cuts through the blast in a posi-tion substantially parallel to the direction of flow of the blast.
15. A method for forming a fiber from attenuable material comprising generating a pair of gaseous jets with axes lying substantially in a common plane and directed to impinge upon each other at an acute angle to each other and to produce a combined jet flow, the jets having substan-tially the same kinetic energy per unit of volume and the jets having substantially the same cross-sectional dimen-sions in directions transverse to and in said plane, and delivering a stream of attenuable material in attenuable condition from an orifice lying in said plane and offset toward one side of both of said jets, the stream of attenua-ble material being delivered into a zone of gas induced by the combined jet flow in the region of impingement of the jets upon each other.
16. A method for forming a fiber from attenuable material comprising generating a pair of gaseous jets with axes lying substantially in a common plane and directed to impinge upon each other at an acute angle and to produce a downwardly directed combined jet flow, generating a gas-eous blast in a path intercepting the combined flow of the jets, and delivering a stream of attenuable material in attenuable condition from an orifice lying in said plane horizontally offset toward one side of both of said jets, the stream of attenuable material being delivered into a zone of gas induced by the combined jet flow in the region of impingement of the jets upon each other the cross-sec-tional area in directions transverse to and in said plane and the kinetic energy of the jets being substantially the same, and the combined flow of the jets having higher kinetic energy per unit of volume than the gaseous blast.
17. Apparatus for forming a fiber from attenuable material comprising means for establishing a pair of gaseous jets with their axes directed in a common plane at an acute angle to each other so that the jets impinge upon each other in said plane, and means for delivering a stream of attenua-ble material from a source in said plane offset to one side of both of said jets, the material being delivered from said source in a path lying in said plane, and extended into a zone of gas induced by one of the jets in the region of impingement of the jets upon each other.
18. Apparatus as defined in Claim 17 in which the jets have substantially the same kinetic energy per unit of volume.
19. Apparatus as defined in Claim 18 in which the jets have substantially the same cross sectional area.
20. Apparatus as defined in Claim 18 in which the angle included between the axes of the jets is between 10° and 90°.
21. Apparatus as defined in Claim 18 and further including a common manifold for feeding the jets.
22. Apparatus for forming a fiber from attenuable material comprising means for establishing a gaseous blast, means for establishing a pair of gaseous jets with their axes directed in a common plane at an acute angle to each other so that the jets impinge upon each other in said plane and develop a combined jet flow extended toward and penetrat-ing transversely into the blast, and means delivering a stream of attenuable material from a source thereof in attenua-ble condition in said plane offset to one side of both of said jets, the material being delivered from said source in a path lying in said plane and extended into a zone of gas induced by one of the jets in the region of impingement of the jets upon each other.
23. Apparatus as defined in Claim 22 in which the jets are positioned so that the common plane of the axes of the jets also contains the path of the blast.
24. Apparatus for forming fibers from attenuable material, comprising means for generating a plurality of pairs of gaseous jets with the jets of each pair directed along converging axes lying substantially in a common plane, to provide for impingement of the jets of each pair on each other with consequent lateral spreading of the combined jet flow of each pair of jets, the means for.generating the pairs of jets being positioned in spaced side-by-side relation sufficiently close to each other to provide for lateral impingement of the combined flow of each pair of jets upon the combined flow of adjoining pairs of jets therehy providing for development of pairs of tornadoes in the combined flow of each pair of jets, with a zone of laminar flow inter-vening between the pairs of t.ornadoes, and means for deliver-ing a stream of attenuable material in attenuable condition into the zone of laminar flow of at least one of the pairs of jets, the material being delivered from a source in said plane offset to one side of both of the-jets of at least one of the pairs of jets and in a path lying in the plane containing the axes of the jets of at least one of the pairs of jets.
25. Apparatus as defined in Claim 24 and further including means for generating a gaseous blast directed in a path intercepting the combined jet flow.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FR77.25691 | 1977-08-23 | ||
| FR7725691A FR2401110A1 (en) | 1977-08-23 | 1977-08-23 | MANUFACTURING OF FIBERS BY MEANS OF GAS CURRENTS FROM A STRETCHABLE MATERIAL |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1122367A true CA1122367A (en) | 1982-04-27 |
Family
ID=9194700
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA306,396A Expired CA1122367A (en) | 1977-08-23 | 1978-06-28 | Method and apparatus for forming fibers from gas blast attenuation |
Country Status (37)
| Country | Link |
|---|---|
| JP (1) | JPS5496121A (en) |
| AR (1) | AR221061A1 (en) |
| AT (1) | AT366999B (en) |
| AU (1) | AU519477B2 (en) |
| BE (1) | BE869896A (en) |
| BR (1) | BR7805434A (en) |
| CA (1) | CA1122367A (en) |
| CH (1) | CH624647A5 (en) |
| DD (1) | DD138336A5 (en) |
| DE (1) | DE2836555A1 (en) |
| DK (1) | DK255778A (en) |
| EG (1) | EG13561A (en) |
| ES (1) | ES472779A1 (en) |
| FI (1) | FI62812C (en) |
| FR (1) | FR2401110A1 (en) |
| GB (1) | GB1595830A (en) |
| GR (1) | GR66475B (en) |
| HU (1) | HU178343B (en) |
| IE (1) | IE47311B1 (en) |
| IL (1) | IL55396A (en) |
| IN (1) | IN150734B (en) |
| IT (1) | IT1159104B (en) |
| LU (1) | LU80134A1 (en) |
| MX (1) | MX149467A (en) |
| MY (1) | MY8500805A (en) |
| NL (1) | NL7808642A (en) |
| NO (1) | NO145504C (en) |
| NZ (1) | NZ188218A (en) |
| OA (1) | OA06028A (en) |
| PH (1) | PH16141A (en) |
| PL (1) | PL116593B1 (en) |
| PT (1) | PT68461A (en) |
| RO (1) | RO76489A (en) |
| SE (1) | SE437979B (en) |
| TR (1) | TR20124A (en) |
| YU (1) | YU201078A (en) |
| ZA (1) | ZA784729B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2499965B1 (en) * | 1981-02-19 | 1985-06-14 | Saint Gobain Isover | PROCESS AND DEVICE FOR THE MANUFACTURE OF FIBERS FROM STRETCHABLE MATERIALS |
| FR2869896B1 (en) * | 2004-05-04 | 2006-07-28 | Saint Gobain Isover Sa | METHOD AND DEVICE FOR FORMING MINERAL FIBERS |
-
1977
- 1977-08-23 FR FR7725691A patent/FR2401110A1/en active Granted
-
1978
- 1978-05-30 GB GB23723/78A patent/GB1595830A/en not_active Expired
- 1978-05-31 SE SE7806297A patent/SE437979B/en unknown
- 1978-06-08 DK DK255778A patent/DK255778A/en unknown
- 1978-06-08 FI FI781840A patent/FI62812C/en not_active IP Right Cessation
- 1978-06-13 NO NO782052A patent/NO145504C/en unknown
- 1978-06-28 CA CA306,396A patent/CA1122367A/en not_active Expired
- 1978-07-18 PH PH21389A patent/PH16141A/en unknown
- 1978-08-14 AR AR273301A patent/AR221061A1/en active
- 1978-08-16 IN IN893/CAL/78A patent/IN150734B/en unknown
- 1978-08-17 IE IE1664/78A patent/IE47311B1/en unknown
- 1978-08-17 MX MX174559A patent/MX149467A/en unknown
- 1978-08-18 OA OA56586A patent/OA06028A/en unknown
- 1978-08-18 RO RO7895012A patent/RO76489A/en unknown
- 1978-08-21 DE DE19782836555 patent/DE2836555A1/en not_active Withdrawn
- 1978-08-21 IL IL55396A patent/IL55396A/en unknown
- 1978-08-21 PT PT68461A patent/PT68461A/en unknown
- 1978-08-21 IT IT26884/78A patent/IT1159104B/en active
- 1978-08-21 ZA ZA00784729A patent/ZA784729B/en unknown
- 1978-08-21 GR GR57049A patent/GR66475B/el unknown
- 1978-08-22 CH CH888478A patent/CH624647A5/en not_active IP Right Cessation
- 1978-08-22 AT AT0610978A patent/AT366999B/en not_active IP Right Cessation
- 1978-08-22 LU LU80134A patent/LU80134A1/en unknown
- 1978-08-22 PL PL1978209168A patent/PL116593B1/en unknown
- 1978-08-22 AU AU39147/78A patent/AU519477B2/en not_active Expired
- 1978-08-22 BR BR7805434A patent/BR7805434A/en unknown
- 1978-08-22 NZ NZ188218A patent/NZ188218A/en unknown
- 1978-08-22 HU HU78SA3130A patent/HU178343B/en unknown
- 1978-08-22 NL NL7808642A patent/NL7808642A/en not_active Application Discontinuation
- 1978-08-22 BE BE190012A patent/BE869896A/en not_active IP Right Cessation
- 1978-08-22 TR TR20124A patent/TR20124A/en unknown
- 1978-08-23 JP JP10192478A patent/JPS5496121A/en active Pending
- 1978-08-23 YU YU02010/78A patent/YU201078A/en unknown
- 1978-08-23 DD DD78207442A patent/DD138336A5/en unknown
- 1978-08-23 ES ES472779A patent/ES472779A1/en not_active Expired
- 1978-08-23 EG EG522/78A patent/EG13561A/en active
-
1985
- 1985-12-30 MY MY805/85A patent/MY8500805A/en unknown
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