US3054140A - Apparatus for manufacturing mineral wool fibers and the like - Google Patents

Description

Sept. 18, 1962 M. s. FIRNHABER 3,054,140

APPARATUS FOR MANUFACTURING MINERAL WOOL FIBERS AND THE LIKE Filed Feb. 20, 1961 2 Sheets-Sheet 1 ATTORNEYS.

Sept. 18, 1962 M. s. FIRNHABER APPARATUS FOR MANUFACTURING MINERAL WOOL FIBERS AND THE LIKE Filed Feb. 20, 1961 2 Sheets-Sheet 2 m R mm MH Wm m a6 a w I m 4 a M M M W w IL H n 00\ M ll E U n q Ir] 3 a 2 /2 a3 (/U 2 Z zxxzzz ATTORNEYS.

United States Patent 3 054,140 APPTUS FOR MANUFACTURING MINERAL WOOL FIBERS AND 'll-E LIKE Miles 53. Firuhaher, Rte. 3, Pewauiree, Wis. Filed Feb. 20, 1961, Ser. No. 90,535 Claims. ((31. 18-26) This invention relates to an improved apparatus for manufacturing mineral wool fibers and the like, and more particularly to a fiberizing rotor especially adapted to produce thin, long, high-quality fibers.

The apparatus comprising the present invention is generally similar to those disclosed in copending applications Serial No. 801,533, filed May 24, 1959, and Serial No. 19,209, filed April 1, 1960, and the present invention is intended primarily as an improvement on said prior devices.

In the operation of a fiberizing apparatus of the general type herein concerned molten glass or similar thermoplastic material is thrown from a rapidly spinning rotor by centrifugal force, and as said material leaves the rotor periphery it is acted upon by a high-velocity blast of steam or other fiberizing agent to produce the thin fibers used in mineral wool and similar products. With conventional fiberizing rotors, however, it has been found that a substantial number of incompletely formed fibers, or so:- called slugs, are produced, which lessens the quality of the finished product, or the fibers are of a larger diameter than is desired.

With the above in mind, the principal object of the present invention is to provide a novel fiberizing rotor assemblage wherein the molten material is passed through an annular, wire mesh screen as it leaves the periphery of the rotor, in order to attenuate and reduce the diameter of the fibers, and to prevent any unforme'd globules or slugs from finding their way into the finished product.

A further object is to provide a rotor assemblage having novel means for detachably securing said annular screen thereon, the detachable nature of said mounting permitting said screen to be quickly and easily replaced in the event it is damaged or worn.

A further object is to provide a rotor assemblage utilizing a fine mesh screen to promote the production of thin, perfectly-formed fibers, as described, which assemblage includes means for continuously directing heat against said annular screen to prevent the molten material from solidifying thereon and clogging said screen.

A further object of the invention is to provide a fiberizing rotor assemblage having special material-retaining means thereon to prevent the molten material from escaping over the edge of the rotor rim without first being passed through the attenuating screen, and which novel retaining means also permit the present rotor to be mounted on a horizontal axis, in contrast to the vertical axis which might otherwise be necessary.

A further object is to provide a rotor assemblage constructed entirely of metal, said rotor having special integral cooling means therein to prevent overheating and structural deterioration of the metal.

A further object of the invention is to provide an improved rotor assemblage wherein all of the major components can be separately detached and replaced in the event they become worn or broken, thereby eliminating the necessity of replacing the entire assemblage, as is required with conventional rotors.

A further object is to provide a fiberizing apparatus wherein the temperature and viscosity of the molten material can be effectively controlled during the fiberizing operation, thereby insuring that the fibers produced are of a consistently fine variety.

3,054,149 Patented Sept. 18, 1962 Still further objects of the present invention are to provide a fiberizing apparatus which is relatively simple in design and construction, and which is reliable and efiicient in operation.

With the above and other objects in view, the invention consists of the improved fiberizing apparatus for use in manufacturing mineral wool fibers and the like, and all of its parts and combinations, as set forth in the claims, and all equivalents thereof.

In the accompanying drawing, illustrating a complete embodiment of the preferred form of the invention and twomodifications thereof, and wherein the same reference numerals designate the same parts in all of the views:

FIG. 1 is a view, principally in vertical section, of the fiberizing apparatus comprising the principal form of the invention;

FIG. 2 is an end view of the apparatus illustrated in FIG. 1;

FIG. 3 is a fragmentary vertical sectional view showing a modification of the principal form of the invention; and

FIG. 4 is a vertical sectional view showing a modification wherein the rotor is mounted on a vertical axis.

Referring now more particularly to FIG. 1 of the drawings, it will be seen that the apparatus comprising the present invention includesa cup-shaped rotor head 11 having a material-receiving cavity 12 in its forward face which is positioned to receive molten material from a delivery trough vl0. Said rotor head is mounted on a hollow, horizontally-disposed drive shaft 13 which is rotatably drivably connected to a motor or other prime mover (not shown), and which shaft is adapted to rotatably drive said rotor head at a high speed. As illustrated, said drive shaft 13 projects into and completely through the rotor head and has a nut 15 threaded onto its outer end to removably retain said rotor head thereon. That portion of the drive shaft extending through the rotor head is tapered slightly to provide a tight, wedge fit and to insure a positive driving engagement with the rotor head. A smaller, concentric hollow tube 14 is carried within said drive shaft 13 and during the operation of the rotor, as will be hereinafter described in greater detail, cold water is pumped through said smaller tube and circulates between said tube and the surrounding shaft 13 as indicated by the arrows in FIG. 1. The result is a water jacket which not only maintains the drive shaft relatively cool, but which extends into and through the rotor head and also prevents the metal interior of said rotor head from becoming overheated.

Like the rotor illustrated and described in the aforementioned copending application Serial No. 19,209, the present assemblage is preferably formed entirely of metal, rather than a combination of metal and refractory materials as is used in conventional fiberizing rotors. Most prior rotors have been constructed at least partially of ceramic materials. Ceramic materials, however, tend to dry out and crack in a short time, necessitating their frequent replacement, and are very unsatisfactory for this reason. With the present invention, however, due to the novel integral cooling system hereinabove described, which prevents the interior of the rotor from becoming overheated, the present rotor can be constructed entirely of metal and there is no necessity for employing inferior ceramic materials.

With reference again to FIG. 1, it will be seen that the forward periphery or rim of the cup-shaped rotor head 11 is provided with a pair of forwardly-projecting annular rim extensions 16 and 19. Said rim extensions are an important feature of the invention as they perform the dual function of providing mounting means for the novel fiber-attenuating screen hereinafter described, and in addition, they prevent molten material from escaping prematurely from the vertically-disposed material-receiving cavity of the rotor head.

The inner rim extension 16 extends forwardly beyond the rotor rim a short distance, and is provided with spaced slotted apertures 17 which are obliquely angled outwardly in the direction of rotation to facilitate the passage of the molten material therethrough, as will be seen. Formed on the forward edge of said rim extension is an inturned annular lip or flange 18 which is designed to minimize the amount of molten material which escapes over the rim without passing through said apertures 17. The outer annular rim extension 19 is concentric with and projects forwardly beyond said inner rim extension, and is provided with an inner set of elongated apertures 20 similar to and in registration with the apertures 17 in said inner rim member. Said outer rim extension also has a second or outer set of apertures 20 forwardly of the inturned lip 18 on said inner rim; and formed on the outer end of said member 19 is a second annular inturned lip or flange 21 designed to further insure against loss of molten material. Said annular rim extensions 16 and 19 are removably secured to the exterior of the rotor head by screws 23 which can be quickly removed when it is desired to remove and replace said rim members.

Carried between the rim extensions 16 and 19, and held in clamping engagement thereby, is a fine wire mesh screen 22. Said screen is preferably formed of a platinum-rhodium alloy, which is well adapted to withstand intense heat, and which preferably has a mesh of between .002 and .035 inch, although the exact composition and specifications of said screening are not critical and may be varied to suit particular fiberizing requirements. A supplementary rim 24 (PEG. 1) is bolted or otherwise detachably secured to and within the outer rim extension 19 to hold the forward portion of the screen 22, said supplementary rim having apertures 24- in registration with the apertures 20 in said outer rim extension.

As shown in FIGS. 1 and 2, the complete fiberizing apparatus also includes a pair of concentric steam rings 25 and 26 which are mounted forwardly of and in surrounding relation to the periphery of the rotor head 11. The smaller, inner ring 26 is provided with spaced apertures 27 through which steam is emitted, and which apertures are positioned so that the steam jets 28 (FIG. 1) will intercept the molten material filaments 32 just as the latter leave the periphery of the rotor. The outer ring 25 functions as a distributor ring to ensure that the stream is distributed about the entire circumference of the inner ring 26 which is in communication therewith.

To supplement and facilitate the fiberizing action of the steam ring 26, a plurality of burners 29 are also mounted in spaced relation about the periphery of the rotor, said burners being designed to direct hot gases or flames 30 against the molten filaments to maintain the same at the proper temperature and viscosity during the attenuating process. It is to be understood, of course, that while said ring 26 and burners 29 have been described as discharging steam, preheated air or any other suitable fiberizing agent may be employed as well, and the invention is not to be limited in this respect.

Mounted with ends adjacent the material-receiving cavity 12 of the rotor head is another set of burners 31 which are positioned around the shaft 13 to direct hot gas against the concave material-receiving surface of the rotor. Said burners not only direct heat against the molten material in the rotor cavity, to maintain the same at a proper temperature and to prevent outside air from contacting and prematurely cooling the same, but due to the cup-like shape of said rotor cavity the hot gases emitted by said burners are deflected outwardly on the rotor rim and prevent said molten material from solidifying on and clogging either the inner or outer portions of the wire screening 22 during the fiberizing operation.

In the operation of the fiberizing apparatus, the molten material deposited in the material-receiving cavity 12 is flung radially outwardly on the rotor head by centrifugal force, as described, and is directed through the registering apertures in the rim extensions 16 and 19, said apertures being angled outwardly in the direction of rotation to facilitate the passage of the molten material therethrough. As said material passes through said rim apertures it also passes through the wire mesh screen 22 carried between said rim extensions, and is formed thereby into relatively thin filaments. During the operation of the rotor the inturned lip 18 on the inner rim extension 16 prevents most of the molten material from riding farther outwardly on the rotor rim and any molten material which should get past said first lip is caught by the lip 21 on the outer rim extension, and is directed thereby through the apertures 20 which are kept heated and open by the discharge from the burners 31.

Immediately after said molten material filaments 32 (FIG. 1) pass through said annular screen they are intercepted by the high-velocity steam blast 28 emitted from the ring 26, which blast abruptly changes the direction of said filaments and attenuates the same still more. As said fibers are being acted upon by said steam blast they are also contacted by the hot gases or flames 30 from the burners 29 which prevent premature cooling and maintain said fibers at the proper temperature and viscosity during their attenuation. The result is that the fibers produced by the present invention are consistently fine, perfectly-formed fibers which are exceptionally well suited for use in products requiring a fine fiber.

As a result of said novel, coacting inturned lip members 18 and 21 on the rotor rim, it has been found that the present rotor assemblage can be mounted on a horizontal axis, as illustrated in FIG. 1, since the molten material is prevented by said lips from flowing out of the verticallydisposed material-receiving cavity 12 as described.

For some fiberizing operations the dual inturned lips 18 and 21 on the rotor head of the principal form of the invention are not necessary and it is sutficient if a single inturned lip is employed. In such instances, as shown in FIG. 3, in which illustration the numerals designating the structural members are the same as those in FIGS. 1 and 2 preceded by the digit 1," the inner rim extension 116 is provided with an inturned lip 118 and the forward end of the outer rim extension 119 terminates adjacent said lip. Thus the molten material is prevented from escaping over the rotor rim solely by the lip 118, but the function and operation of the apparatus is otherwise similar to that hereinabove described, the molten material passing through the registering apertures 117 and 120 in the rim extensions and through the screening 122 carried therebetween.

As illustrated in FIG. 4, it is also possible to advantageously employ many of the novel features characterizing the present invention in a rotor mounted on a vertically-disposed drive shaft. The vertically-mounted rotor shown in said FIG. 4 is generally similar to that disclosed in the aforementioned copending application, Serial No. 19,209, and the parts corresponding to those included in the principal form of the present invention (FIGS. 1 and 2) are preceded by the digit 2.

Although the inturned lips 218 and 221 on the rim extensions illustrated in FIG. 4 are not as vital in a rotor which is mounted on a vertical drive shaft, since there is less tendency for the material to escape the horizontal material-receiving surface of the rotor, it still happens with such rotors that a substantial number of unformed globules or slugs find their way into the finished product. With the addition of the inturned lips 218 and 221, however, such occurrences are eliminated. Moreover, of course, the novel screen 222 ensures the production of consistently thin fibers, and is useful in either type of rotor. The result is that While the improved structure comprising the present invention is especially designed for use in a rotor assemblage mounted on a horizontal 5.) axis, the structure also has decided advantages in a rotor mounted on a vertical axis.

From the foregoing detailed description it will be seen that the present invention provides an improved fiberizing apparatus which constitutes a definite advancement in the art. Due to the use of an annular screen, the present rotor structure is not only designed to produce consistently fine, high-quality fibers of the type preferred in mineral wool and similar products, but there are no unformed fibers or slugs in the finished product. In addition, due to the novel material-retaining lips formed on the rotor head, the present structure can be mounted on a horizontal drive shaft which is advantageous in certain situations.

Further advantages inherent in the present rotor assemblage are the fact that the entire structure can be easily and quickly disassembled and the various components individually replaced or repaired in the event of damage. This is not possible with most conventional fiberizing devices, and with the present rotor structure it is also possible to utilize metal throughout, due to the novel cooling system employed therein, and it is unnecessary to use a combination of metal and ceramic materials, such as is used in conventional fiberizing devices.

It is to be understood, of course, that variations or modifications in the construction of the apparatus hereinabove described will suggest themselves to persons skilled in the art, and all of such variations or modifica- .tions are contemplated as may come within the scope of the following claims.

What I claim is:

1. In a fiberizing rotor having a rotatably mounted head with a concave material-receiving surface; an annular rim surrounding said material-receiving surface, said rim having apertures therethrough through which molten material flung centrifugally from said rotor head is intended to pass; an annular inturned lip on the outer edge of said rim, and a second annular inwardly-projecting lip between said first lip and said material-receiving surface, there being apertures in the rim both inwardly and outwardly of said second lip, said lips being adapted to prevent molten material from escaping from said rotor head without passing through said rim apertures.

2. A fiberizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim detachably secured around the periphery of said materialreceiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end and having an inturned annular lip, said projecting portion having relatively large openings therein, and a fine mesh screen of material which is more heat resistant than the material of the rim positioned against said projecting portion of the rim and covering said openings, the mesh of said screen being of a size to attenuate molten material as the same is thrown centrifugally from the material-receiving surface and said mesh providing openings which are substantially smaller than the openings of the rim.

3. A fiberizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim detachably secured around the periphery of said materialreceiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end, said projecting portion having relatively large openings therein, and a fine mesh screen of material which is more heat resistant than the material of the rim positioned against said projecting portion of the rim and covering said openings, the mesh of said screen being of a size to attenuate molten material as the same is thrown centrifugally from the material-receiving surface and said mesh providing openings which are substantially smaller than the openings of the rim whereby there is a multiplicity of screen openings for each rim opening.

4. A fiberizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end, said projecting portion having relatively large openings therein, a fine mesh screen of platinum rhodium alloy which is more heat resistant than the material of the rim positioned against said projecting portion of the rim and covering said openings, the mesh of said screen being of a size to attenuate molten material as the same is thrown centrifugally from the material-receiving surface and said mesh providing openings which are substantially smaller than the openings of the 5. A fiberizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end, said projecting portion having relatively large openings therein, a second annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said materialreceiving surface and having openings in said projecting portion which are in registration with the openings of the first rim, and a fine mesh screen supported between said two rim members whereby molten material thrown centrifugally through said registering openings of the rim members must pass through the mesh of said screen.

6. A fiberizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end, said projecting portion having relatively large openings therein, a second annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said materialreceiving surface and having openings in said projecting portion which are in registration with the openings of the first rim, and a fine mesh screen of platinum-rhodium alloy supported between said two rim members whereby molten material thrown cen-trifugally through said registering openings of the rim members must pass through the mesh of said screen.

7. A fiberizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end, said projecting portion having relatively large openings therein, a second annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said materialreceiving surface and having openings in said projecting portion which are in registration with the openings of the first rim, a fine mesh screen supported between said two rim members whereby molten material thrown centrifugally through said registering openings of the rim members must pass through the mesh of said screen, and means for directing heat against said screen to prevent molten material from solidifying thereon.

8. A fib-erizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim secured around the periphery of said material-receiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end, said projecting portion having inner and outer sets of relatively large openings therein and having an inturned outer edge lip, a second annular metal rim member detachably secured around the periphery of said materialreceiving member within said first rim and having a portion which projects outwardly beyond the material-receiving surface a lesser distance than the projecting portion of the first rim and having an annular inturned lip which is positioned between the lip of the first rim and said material-receiving surface, said second rim having openings, in registration with the first set of openings of the first rim, fine mesh screening positioned between said two rim members so that molten material passing through the first set of openings must pass through the mesh of said screening, and fine mesh screening supported over the second set of openings of said first rim member.

9. A fiberizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim detachably secured around the periphery of said materialreceiving member and having an annular portion projecting beyond said material-receiving surface and having an open outer end, said projecting portion having inner and outer sets of relatively large openings therein and having an inturned outer edge lip, a second annular metal rim member detachably secured around the periphery of said material-receiving member within said first rim and having a portion which projects outwardly beyond the material-receiving surface a lesser distance than the projecting portion of the first rim and having an annular inturned lip which is positioned between the lip of the first rim and said materialn'eceiving surface and between the first and second sets of openings of said first rim, said second rim having openings in registration with the first set of openings of the first rim, fine mesh screening positioned between said two rim members so that molten material passing through the first set of openings must pass through the mesh of said screening, and fine mesh screening supported over the second set of openings of said rfirst rim member.

10. A fi berizing rotor having a rotatably supported material-receiving member with an outer material-receiving surface and having a periphery, an annular metal rim detachably supported around the periphery of said materialreceiving member for removal by movement axially of the rotor and having an annular portion projecting beyond said material-receiving surface and having an open outer end and having an inturned annular lip, said projecting portion having relatively large openings therein, a fine mesh screen of material which is more heat resist-ant than the material of the rim positioned against said rim member whereby molten material thrown centrifugally through said openings of the rim member must pass through the mesh of said screen, said mesh providing openings which are substantially smaller than the openings of the rim whereby there is a multiplicity of screen openings for each rim opening, means for detachably clamping the rim and screen in position around said rotor periphery whereby the screen is supported against displacement by the rim and whereby either the rim or screen may be readily replaced, and means for directing'heat against said screen to prevent molten material from soliditying thereon.

References Cited in the file of this patent UNITED STATES PATENTS 773,614 Westaway Nov. 1, 1904 2,192,944 Thomas Mar. 12, 1940 2,431,205 Slayter Nov. 18, 1947 2,980,952 Stalego Apr. 25, 1961 2,980,954 Levecque et a1, Apr. 25, 1961

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