US3542533A - Rotor construction for centrifugal rotor fiberization - Google Patents

Description

Nov, 24, 1970 w. K. HESSE ROTOR CONSTRUCTION FOR CENTRIFUOAL ROTOR FIBERIZATION Filed July 25, 1968 mi N. 1K 2 MTV 3,542,533 ROTOR CONSTRUCTION FOR CENTRIFUGAL ROTOR FIBERIZATION Walter Kasper Hesse, Martinsville, N.J., assignor to Johns- Manville Corporation, New York, N.Y., a corporation of New York Filed July 23, 1968, Ser. No. 746,991 Int. Cl. C03b 37/04 US. Cl. 6515 9 Claims ABSTRACT OF THE DISCLOSURE An improved rotor construction for centrifugal formation of filaments of thermoplastic material in fiberization systems wherein the peripheral wall of the rotor having radial directed orifices for filament ejection is constructed as a double walled closed annular chamber for circulation of coolant.

BACKGROUND OF THE INVENTION In centrifugal rotor fiberizing systems for the manufacture of thermoplastic fibers such as glass wherein a rotor distributes the molten material and forms and ejects primary filaments thereof radially through the orifices in the annular wall surrounding the periphery of the rotor for attenuation into fine fibers by means of an impinging gaseous blast, the diameter of the primary filaments thus formed and then attenuated constitutes a significant factor in determining the size and in turn the insulating properties, among other significant characteristics, of the resultant fibrous product. And, the diameter of the primary filaments issuing from the rotor orifices at any given viscosity of the molten material which is a function of the temperature and given revolutions per minute of the rotor creating the centrifugal force, is directly attributable to the diameter of the orifices of the forming rotor. Although the rotor wall orifices can easily be initially made to precise dimensions, continuous exposure to the very aggressive conditions of the high temperature of melts such as glass and the abrasion of the ejecting molten material passing therethrough rapidly and erratically erodes away the adjacent metal not only enlarging the size of the orifice but distorting its shape and thereby degrading the fibrous product formed and the fiberizing procedure. In addition to being detrimental to the manufacturing operation and product quality, the metal components of the rotor are warped and distorted and the apparatus is rapidly deteriorated by the high temperatures requiring uneconomical frequent replacements and loss of production, or remedial measures of the use of excessively costly metals such as platinum rotors or components like platinum orifice insert liners.

SUMMARY OF THE INVENTION This invention comprises an improved rotor or rotor construction design wherein the annular wall about the rotor periphery constitutes a double walled, closed chamber with the rotor orifices for the formation and ejection of the primary filaments comprising conduits passing through the annular closed chamber in radial direction whereby the integrity and dimensions of the rotor wall and orifices can be maintained by a coolant circulating through the closed chamber and passing about the orifices and the conduits connected therewith.

Objects and advantages of the improved rotor or rotor construction of this invention comprise an apparatus which Patented Nov. 24, 1970 will effectively endure higher temperature conditions or melts of up to about 2600 F. or greater without deterioration or distortion of its essential structure or dimensions, maintain the critical primary filament forming and ejecting orifice size and configuration by resisting erosion and wear over prolonged periods of use and contact with very high temperature melts thereby preserving the quality and consistency of the product and of the forming operation, and extensively prolongs the serve life of the apparatus.

BRIEF DESCRIPTION OF THE DRAWING The above and other objects and advantages of the improved rotor of this invention as well as construction details will become more apparent in the hereinafter detailed description of preferred embodiments thereof and the accompanying drawings in which:

FIG. 1 is a pictorial view illustrating a rotor constructed according to this invention, with a cut away portion showing the conduits passing through the closed chamber;

FIG. 2 is a vertical sectional view of the rotor peripheral wall along lines 11-11 of FIG. 1 illustrating in detail the conduits traversing the closed chamber and connecting the outlet orifices within the Walls of the chamber;

FIG. 3 is a vertical sectional view of the rotor peripheral wall similar to that of FIG. 2, illustrating in detail a modified cooling system; and,

FIG. 4 is a pictorial view of the underside of a rotor construction illustrating a further embodiment of a cooling system.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, the centrifugal rotor 10 is composed of circular base plate 11, mounted on drive shaft 12 conventionally provided with suitable mounting bearings, not shown, and connected with means such as a motor to rotate the rotor at high speed. The annular wall 13 about the periphery of the base plate 11 and extending generally upwardly therefrom, is constructed of a first or inner wall 14 and a second or outer wall 15, each fixed to the base plate 11 and generally parallel to each other. Walls 14 and 15 are provided with a top 16 to form, along with a portion of base plate 11, an annular enclosure or closed chamber 17 for the containment and circulation of a fluid coolant.

A plurality of complemental pairs of orifices 18 and 19 are provided in the first and second walls 14 and 15 respectively and each complemental pair 18 and 19 of walls 14 and 15 is connected to each other in sealing relationship by means of conduits 20 providing radial directed outlets 21 through annular closed chamber 17. Outlets 21, formed by conduits 20 connecting each complemental pair of orifices 18 and 19 are preferably provided in a multiplicity of vertically arranged rows as illustrated with the diameter of outlets 21, their number and dispersion according to conventional practice for the particular conditions to be employed.

Fluid coolant for circulation through annular closed chamber 17 surrounding outlets 21 formed by conduits 20 connecting complemental pairs of orifices 18 and 19, is carried to and from chamber 17 by means of tubes 22 and 23 concentrically arranged one within the other and extending down through drive shaft 12 then, as shown by the broken lines, extending outwardly under rotor base 11 to the periphery thereof where they are connected with closed annular chamber 17 for the supply and return of fluid coolant circulating through chamber 17.

Pipe 24 delivers molten material such as glass to the rotor and deposits the melt on rotor base 11 for dispersion by the rapidly rotating rotor whereupon the developed centrifugal force distributes the molten material substantially uniformly over the interior of annular wall 13 extending upwardly from base 11 and then outwardly through outlet orifices 21 in substantially continuous filaments of highly uniform diameter into the path of an appropriately directed gaseous blast not shown for attenuation as is conventional in rotor fiberization systems.

In the embodiment illustrated in FIG. 3 coolant fluid is carried into the closed chamber 17 and permitted to be discharged downwardly from under the rotor base 11 away from the area of primary filament ejection and gas blast attenuation. Referring to the drawing of FIG. 3, coolant conduit 22 extends from drive shaft 12 under rotor base 11 carrying coolant fluid to chamber 17 through opening 25 in the rotor base 11. Closed chamber 17 is divided by baflle 26 extending up from the rotor base 11, positioned generally intermediate and parallel to the first and second walls 14 and 15 to a height short of contact with top 16 to provide for fluid communication through the chamber 17 over baffle 26. fluid coolant inlet opening 25 is positioned in the rotor base 11 on one side of baffle 26 and a fluid coolant outlet opening 27 is positioned on the opposite side of baffle 26 whereby the flow of coolant from conduit 22 passes upwardly from the inlet opening 25 in chamber 17 over baffle 26 and down in chamber 17 and exits through outlet 27, thus effectively contacting all potrions of the interior of chamber 17 and conduits connecting the complemental pairs of orifices 18 and 19 which function to form and eject primary filaments, radially outwards thereby cooling and preserving the structure. The number and location of coolant carrying conduits 22 distributing the coolant fluid to chamber 17 and chamber 17 inlet and outlets 25 and 27, or baffle arrangement 26 may of course be varied to meet the temperature conditions of any particular system.

FIG. 4 illustrates a typical apparatus for use with a molten metal coolant requiring a closed circuit system whereby circulation is achieved by rotational forces. In this embodiment a low melting material such as tin, zinc, lead, etc. fills the closed annular chamber 17 and the ducts of the closed circuit which is formed by ducts 28 fixed below rotor base 11, preferably in a circuitous path to extend their exposure to the atmosphere and available cooling surfaces. Ducts 28 are in communication with closed annular chamber 17 through openings 29 through rotor base 11. Chamber 17 may additionally include bafiles such as 26 in FIG. 3 to prevent channeling of the coolant and achieve maximum circulation. The heat transferring and dissipating ducts 28, fixed below rotor base 11, may be deployed in any apt arrangement or number such as a nest of tubes to achieve efficient cooling or dissipation of the heat carried away from chamber 17 including the use of cooling fins, not shown, commonly employed to increase heat radiating surfaces, or to induce surrounding air currents passing over the cooling means.

In addition to providing baflles in closed annular chamber 17 to control or direct the circulation of coolant fluid to achieve maximum effectiveness, the chamber can be divided into segments to correspond with independent sectional coolant distributors such as a manifold coolant supply and return. Also the supply of coolant and/ or its temperature can be regulated to achieve the freezing of a thin coating of the molten material being fiberized about the surface of outlets 21 including conduits 20 with orifices 18 and 19 and inner wall 14 thereby providing a protective layer on all critical surfaces with the solidified melt shielding such areas from wear. Additionally, through control of the thickness of the protective coating through regulation of the coolant the diameter of the primary filament forming orifices 21 can be adjusted, especially to offset their enlargement due to wear.

Centrifugal rotors of the construction or design of this invention may of course be fabricated from any suitable metal or alloy possessing adequate thermal resistance to meet the particular melt temperature conditions of its intended application, and with suitable metals or alloys available and known to the art the invention makes operations practical with melts ranging up to approximately 3000 F.

It will be understood that the foregoing details are given for the purpose of illustration, not restriction, and the variations within the spirit of this invention are intended to be included within the scope of the appended claims.

What I claim is:

1. In an apparatus for use in rotary systems of fiberization wherein a supply of molten material is deposited on the base of the rotor and urged by the centrifugal force of rotation through orifices in a peripheral wall of the rotor to produce filaments of the molten material for attenuation into fibers, including: (a) a circular rotor base having a peripheral Wall means extending upwardly therefrom; (b) means for rotating said base about an axis extending generally perpendicular thereto; and, (c) the improvement comprising the peripheral wall means of said circular rotor base having a first and second wall forming a double wall closed annular chamber extending upwardly from the periphery of the circular rotor base, each the first and second walls extending upwardly from the base having a plurality of complemental pairs of orifices therein connected to each other in sealing relationship by means of a conduit to provide radial outlet passages thorugh the double wall closed annular chamber comprising the peripheral wall means extending upwardly from the periphery of the circular rotor base for the centrifugal formation and ejection of molten filaments and means for circulating cooling fluid through the rotary system.

2. In an apparatus of claim 1 wherein the plurality of complemental pairs of orifices in the said first and second walls and connected to each other in sealing relationship with a conduit passing through the double wall closed annular chamber providing radial outlet passages therethrough are arranged in at least two annular rows about the peripheral wall means.

3. In an apparatus of claim 1 wherein the double walled closed annular chamber extending upwardly from the periphery of the circular rotor base has at least two conduits communicating with the interior thereof to provide for the supply and return of fluid coolant circulating into and through the double walled closed annular cham- 4. In an apparatus of claim 3 wherein the circular rotor base is supported by and rotated through a hollow dry shaft secured centrally thereto and the two conduits communicating with the interior of the wall enclosed annular chamber for the supply and return of the circulating coolant extend down through the hollow dry shaft with one concentrically positioned within the other to the underside of the rotor base.

5. In an apparatus of claim 4 wherein the plurality of complemental pairs of orifices in the first and second walls and connected to each other in sealed relationship with a conduit passing through the double walled closed annular chamber providing radial outlet passages therethrough are arranged in at least two annular rows about the peripheral wall means.

6. In an apparatus of claim 1 wherein the double Wall enclosed annular chamber extending upwardly from the periphery of the circular rotor base has at least one conduit communicating with the interior thereof to provide for the supply of fluid coolant circulating into and through the, double walled closed annular chamber and said chamber having at least one outlet opening in the underside thereto for the discharge of the circulating fluid coolant.

7. In an apparatus of claim 1 wherein the double walled closed annular chamber extending upward from the periphery of the circular rotor base is connected in fluid transmitting relation to a duct system fixed in position on the underside of the rotor base and forming a closed circuit with the annular chamber to provide means of dissipating from the coolant fluid the heat removed from the closed annular chamber.

8. In an apparatus of claim 7 wherein the duct system fixed in position on the underside of the rotor base in fluid transmitting relation with the closed annular References Cited UNITED STATES PATENTS 3/1952 Downey a- 656 3/1966 Simmers 65-6 10 S. LEON BASHORE, Primary Examiner R. L. LINDSAY, JR., Assistant Examiner US. Cl. X.R'..

chamber and forming a closed circuit therewith com- 15 18-25; 6516;2648

prises a nest of tubes.

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