US3058322A - Apparatus for manufacturing mineral wool fibers - Google Patents

Description

Oct. 16, 1962 E. ERAR D APPARATUS FOR MANUFACTURING MINERAL WOOL FIBERS Filed April 29, 1959 INVENTOR. im/img A A7 (JR/V15 5.

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United States Patent Ofiice 3,658,322 Patented Oct. 16, 1962 3,058,322 APPARATUS FOR MANUFACTURING MINERAL WOOL FIBERS Edward Louis Erard, Saratoga 275, Mexico City 10, Mexico Filed Apr. 29, 1959, Ser. No. 809,683 3 Claims. (Cl. 65-14) This invention relates to an improved apparatus for manufacturing mineral wool fibers and the like, and more particularly to apparatus for producing unusually fine fibers especially suitable for use for insulation purposes.

The present invention relates generally to apparatus for manufacturing mineral wool and similar fibrous products wherein molten glass or the like is thrown from a rapidly spinning rotor by centrifugal force and acted upon by a fiberizing agent to produce elongated threads or fibers. The principal object of the invention is to provide an improved apparatus whereby the temperature and viscosity of the molten material can be controlled throughout the fiberizing operation to insure the production of consistently fine, high-quality fibers.

A more specific object is to provide a fiberizing apparatus wherein heated air and gases from the melting furnace are directed to a predetermined central location on the top surface of the rotor, there being special means for maintaining the molten material at a high temperature during transfer from the furnace, and there being a specially-designed and positioned gas burner to maintain the material on the rotor at the proper temperature.

Another specific object of the invention is to provide apparatus for producing mineral wool fibers wherein the molten material discharged from the melting furnace is directed through a funnel-like delivery tube onto the center portion of the rotor, rather than to the outer portion thereof, thereby insuring complete fiberization of the material and minimizing the number of slugs or incompletely-formed fibers in the finished product.

A further specific object of the present invention is to provide an apparatus for the purposes described wherein the gas burners are shielded to prevent stray slugs or fibers from clogging or otherwise impairing their efficiency, and wherein the top surface of the rotor is shielded to prevent cold air from contacting and prematurely cooling the molten material thereon.

A further specific object is to provide apparatus wherein a multiplicity of high-velocity, specially-positioned fiberizing jets of steam or gas such as high pressure air are used.

With the above and other objects in view, the invention consists of the improved fiberizing apparatus, and all of its parts and combinations, as set forth in the claims, and all equivalents thereof.

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

FIG. 1 is a view, principally in vertical section, showing the improved apparatus operatively associated with a melting furnace;

FIG. 2 is an enlarged vertical sectional view of the fiberizing apparatus;

FIG. 3 is a bottom plan view of the steam ring and rotor shield, taken along line 33 of FIG. 2, with portions of the ring broken away and shown in section; and

FIG. 4 is a fragmentary sectional view through a portion of the melting furnace, taken along line 4-4 of FIG. 1, and showing the top of the funnel.

Referring now more particularly to the drawings, the numeral designates a furnace in which glass is reduced to a molten state, there being an inclined passageway or trough 11 into which the molten material normally flows. In the present construction the passageway 11 communicates with a funnel-like chute 13 which forms the top portion of an elongated, metal delivery tube 13, the lower open end of said vertical delivery tube being positioned directly above the fiberizing rotor 14. The object of this tube is to prevent the chilling of the stream of glass by the surrounding air, and a further object is to prevent the stream of glass from wobbling around on the rotor by the action of the turbulence of air created by the rapidly spinning rotor. It has been found that the chute and tube perform well when formed of Nichrome #5 but it is possible, of course, to form these members of any corrosion and heat resisting steel or other alloy which will withstand temperatures up to and exceeding 2500 F.

In operation, molten material and hot furnace gases are delivered through the tube 13 onto the top surface of the rotor, the molten material being thrown radially outwardly from the rapidly spinning rotor by centrifugal force. With respect to the present invention, the exact type or style of rotor is not critical, the illustrated rotor 14 being of a conventional type having a metal body 30 and a ceramic top portion 31 which is shaped to form a receptacle onto which the molten material may be fed. The rotor is mounted on a suitably driven shaft 33.

As illustrated in FIG. 4, the funnel 13' is semi-circular in cross section and is tapered so as to become progressively narrower toward its junction with the tube 13, which tube has a relatively small diameter. One side of said funnel 13 is provided by the surface of a ceramic wall 15 in said furnace. A transverse steel plate 16 is embedded in the furnace wall-15 near the junction of the chute and tube members, the outer edge of said plate normally being flush with the surface of the wall. In practice, it has been found that molten material and gases flowing down the wall '15 wear upon and erode the latter so that eventually a portion of the molten material is no longer directed into the delivery tube 13 as intended. The plate 16, however, forms a protruding wear resisting shelf so that even when the wall above it has been substantially worn away the molten material is caught and re-directed into the delivery tube. As will best be seen in FIGS. 1 and 2, the elongated delivery tube 13 is extended downwardly through a plate 17 secured to the bottom of the furnace, said plate covering the normal furnace outlet 12 and helping to support the fiberizing apparatus.

A circular gas chamber 18 is mounted on the downwardly-projecting portion of the tube 13 intermediate its length. In practice, a mixture of combustible gases is supplied to said chamber under pressure through a conduit "19 leading from a source of supply which is not shown herein. A plurality of adjustable radiant burners 20 are attached to the bottom of said circular chamber, the flame 21 of each burner being directed against the top surface of the rotor. The purpose of the burners 20 is to maintain the molten material deposited on the rotor at a sufficiently high temperature during the fiberizing operation.

Suspended from the gas chamber 18 by an arm 22 is an inverted, cup-like metal hood or shield 23 which also surrounds the molten material delivery tube 13 and which substantially covers the top surface of the rotor to prevent cold air from contacting and prematurely cooling the molten material thereon. The top of said hood is provided with a plurality of openings 24 (FIG. 2), which are positioned directly beneath the gas burners 20 to permit the flames 21 to pass downwardly therethrough against the rotor. Although for purposes of illustration a plurality of burners to heat the rotor surface have been mentioned, it is understood that an infinite Variety of burner designs may be used for this purpose: for example, one large burner to discharge directly onto the surface of the rotor as shown, while being contained in and protected by hood 23.

A hollow steam ring is mounted on and encircles the lower portion of the hood 23', said ring having a plurality of spaced orifices 26 in its bottom surface and a pair of inlet conduits 27 and 28 leading from a boiler or other source, there being any suitable means for controlling the pressure from said source. Said ring 25 is of a diameter greater than the diameter of the rotor top and is designed to discharge a high-speed, annular blast of steam 32 downwardly against the glass threads as the latter leave the periphery of the rotor. In the illustrated form of the invention the ring orifices are in oblique sets or lines of three, each line being at a degree, or more, angle to the radius of the ring, and there preferably being a set every 12 degrees about the ring circumference. This has been found to be an unusually effective arrangement, but it is not intended to limit the invention in this respect. Partitions 29 separate the ring into two semi-circular sections, each section having its own inlet conduit 27 or 28, the purpose of this being to insure that all of the orifices exert an equal downward pressure.

Operation In the operation of the fiberizing apparatus comprising the present invention, molten material and hot furnace gases flow down the inclined furnace passageway 11 in a stream. The material is directed by the funnel-like chute 13 into the elongated delivery tube 13 which extends downwardly to a point just above the top surface 31 of the rotor. Said tube 13 is accurately positioned to deposit the material and gases onto the center portion of the rotor, rather than on the outer portion thereof, which is an important feature of the invention. In this connection, conventional ceramic rotor tops are provided with radial grooves as shown, which form the material into a multiplicity of streams as it is thrown outwardly toward the rotor periphery. By depositing the molten material onto the center of the rotor, as described, the complete separation of the material into individual streams is promoted and the number of slugs or incompletely formed fibers in the finished product is greatly reduced.

A further advantage of the assembly hereinabove described is that the intensely hot gases from the gas burner are utilized to maintain the molten material at the precise high temperature required during the fiberizing process. To obtain fibers of any desired diameter, the control of the temperature inside of the hood 23 may be accomplished by means of automatic temperature control apparatus 23 suitably connected with the gas burner. Heretofore, in conventional fiberizing assemblages, wherein the molten material is discharged directly through the relatively large furnace outlet 12, the furnace gases have been permitted to escape into the atmosphere. 'In the present construction, however, the delivery chute and tube device 13 inter-mixes the hot furnace gases with the molten material and deposits both onto the rotor. In practice, the constant supply of hot gases thus directed against the top surface of the rotor helps to maintain the molten material thereon at a proper temperature and viscosity and greatly enhances the production of consistently fine, high quality fibers.

The gas burners 20 further heat the molten material, as mentioned, and constitute an important element of the appartus. As will be seen in FIG. 2, the burners are positioned to contact and heat the molten streams as they move radially outwardly on the rotor, thereby preventing the material from cooling before it reaches the rotor periphery. The hood 23 covers the top surface of the rotor to prevent outside air from contacting and prematurely cooling the molten material, and it also serves to shield the gas combustion burners 20 and prevent stray fibers or slugs from clogging or otherwise inparing their efficiency.

As the streams of molten material are fiung from the periphery of the rotor by centrifugal force they are intercepted by the high-velocity, annular steam fiberizing blast 32 emitted from the ring 25. As the fiberizing blasts of steam or air engage the thin streams of glass issuing from the spinning rotor, the direction of these streams is violently deviated from horizontal to downward. At this moment a tremendous increase in velocity is imparted to the thin streams of hot glass, in addition to their velocity of ejection from the rotor, by the blast of steam or air, and it is this increase in velocity which elongates and attenuates the thin streams of glass into fine fibers of controlled diameter. The fineness of the fibers is determined by the adjustment of the rotor burners 20', and the pressure of the steam of air maintained in the fiberizing blast ring 25.

As will be readily appreciated from the foregoing detailed description, the present invention provides an improved apparatus for manufacturing mineral wool fibers and the like wherein the temperature and viscosity of the molten material is maintained throughout the fiberizing operation to insure the production of consistently fine, high-quality fibers.

It is to be understood, of course, that variations or modifications of the apparatus described herein will suggest themselves to those skilled in the art, and all such variations or modifications are contemplated as may come Within the scope of the following claims.

What I claim is:

1. An apparatus for manufacturing mineral wool having an upright supporting and driving shaft and having a rotor mounted thereon with an external upwardly facing end receiving face, and there being a source of supply for molten material above said rotor, a delivery tube for said molten material extending from said source and having a lower discharge end positioned adjacent the rotor and over the center thereof, an annular series of burners surrounding said tube at a location spaced above its upper end and having nozzles positioned to direct flame and gases onto the rotor in a ring surrounding the lower portion of said delivery tube, a shield below said burner nozzles surrounding said lower portion of the delivery tube and supported in fixed position surrounding the discharge from said burner and terminating short of the top of the rotor, and having a top wall through which said delivery tube extends, the nozzles of said burners being above said wall and the latter having holes positioned to allow passage therethrough of the discharge from the burner nozzles together with entrained air from the exterior, and means for directing a fiberizing agent under pressure against molten material thrown centrifugally from the periphery of said rotor to fiberize the latter.

, '2. In an apparatus for manufacturing mineral wool having a rotor with an external end receiving face, means for feeding molten material onto said external receiving face while the latter is rotating, a hollow ring sup-ported adjacent the periphery of said end receiving face and having an annular flat external bottom face, means for conducting a fiberizing agent under pressure into said ring, said fiat bottom face of the ring having a plurality of outlets for said fiberizing agent positioned so that molten material thrown centrifugally from the periphery of said end receiving face will be acted upon and fiberized by said fiberizing agent promptly after emerging from said outlets, said outlets being in a multiplicity of spaced sets extending around the ring with each set forming an oblique line with respect to the radius of the ring.

3 In an apparatus for manufacturing mineral wool having a rotor with an external end receiving face, means for feeding molten material onto said external receiving face while the latter is rotating, a hollow ring supported adjacent the periphery of said end receiving face and having two semi-circular separate chambers, means for conducting a fiberizing agent under pressure into each chamber of said ring, said ring having a plurality of external outlets for said fiberizing agent positioned so that molten material thrown centrifugal-ly from the periphery of said end receiving face will be fiberized by said fiberizing agent, said outlets being in a multiplicity of spaced sets extending around the ring with each set forming an oblique line with respect to the radius of the ring.

References Cited in the file of this patent UNITED STATES PATENTS 1,294,909 Howell Feb. 18, 1919 1,620,207 Howard Mar. 8, 1927 1,939,391 Curran Dec. 12, 1933 6 !Von Reis Mar. 28, 1939 Richardson Feb. 13, 1940 Rosengarth et a1. Mar. 4, 1941 Ramseyer May 27, 1941 Drill et a1. Sept. 15, 1943 Freeman et al. May 15, 1945 'Stalego et al July 22, 1952 Slayter et a1. Sept. 9, 1952 I-Iaymes et al Jan. 13, 1953 Richardson May 28, 1957 Snow et a1. Dec. 9, 1958 F-irnhaber et a1. Feb. 24, 1959 Kleist May 17, 1960 FOREIGN PATENTS Australia Sept. 18, 1951 France Dec. 15, 1954

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