GB673561A - Improvements in or relating to apparatus and method for converting molten mineral material into fibrous form - Google Patents

Abstract

673,561. Making glass &c. fibres. JOHNS-MANVILLE CORPORATION. June 20, 1950, No. 15376/50. Class 56. Fibres are formed from molten mineral wool forming material by intercepting a stream of molten material by a rotating annular surface and projecting material therefrom, intercepting the projected material on a molten material retaining annular surface rotating at higher speed than the first surface, and projecting material therefrom on to another molten material retaining annular surface rotating at higher speed. As shown a stream of molten material 14 from the furnace 10 impinges against the peripheral surface of a distributer roll 16 to the left of a vertical line through the axis of the distributor which is supported on a shaft 20 carried in bearings 22 on the frame 24 and rotated in the direction of the arrow, Fig. 2. The peripheral surface of the roll has a large central groove and marginal fine V grooves. The fiberising means comprises rotors 30, 32 on shafts 34, 36 in bearings 38, 40, rotor 32 being driven in the same direction as roll 16, and rotor 30 in the opposite direction. The rotors are wider and of greater diameter than the roll, e.g. twice the width, and two or three times the diameter, and the peripheral surfaces are preferably grooved as at 42, e.g. 20-40 grooves to the inch. Shafts 34, 36 are arranged at an angle, preferably about 12 degrees to the horizontal, and shaft 20 is at a smaller angle and also at an angle of about 6 degrees to the vertical planes of shafts 34, 36, the shafts being adjustable vertically and horizontally. Roll 16 and rotors 30, 32, or at least the peripheral portions thereof, are formed of heat resistance steel or the like. The stream 14 strikes the roll 16 and is partially bonded in the grooves thereof to form an annular ring of bonded material, while the main portion is projected at greatly accelerated speed tangentially from the roll, and impinges principally on the periphery of rotor 30 and partly on rotor 32. The material striking rotor 30 partially bonds thereto, while unbonded molten material is discharged from this rotor to the grooved periphery of rotor 32 to form a bonded ring, and there may be some rebounding of material between rotors 30, 32. The molten material is thrown off from the rings by centrifugal force and drawn into fibres, and fiberisation also takes place in the bight between rotors 30, 32 by the pulling of the material from the surface of the opposite rotor. The space between rotors 30, 32 is, say, # to 1/32 inch, and in an example rotors 30, 32 of 12 inch diameter are driven at approximately 4,250 and 4,400 r.p.m. respectively, and roll 16 of 6 inch diameter at 3,500 r.p.m. The rotor speeds, fluidity , of melt, and grooving of rotors are varied to meet given conditions. A binder may be applied to the fibres. In the embodiment shown in Figs. 1a and 3a the main fiberisation is performed by rotors 116, 118, preferably grooved, which are rotated in the directions indicated. Rotors 126, 128, which spread and distribute the stream, are supported on shafts above rotors 116, 118, and are of frusto-conical form with the coned surfaces in reversed relationship. Rotor 126 may be smooth and rotor 128 provided with one or more grooves of large cross section. The front bearings of the rotors are yieldably mounted to permit movement as solid chunks of slag &c. are encountered. In an example rotors 126 and 128 were driven at peripheral speeds in the range of 2,500-5,000 feet per minute and 6,500-10,000 feet per minute, while rotors 116 and 118 were driven in ranges of 12,000-16,000 feet per minute and 14,000-20,000 feet per minute respectively. In a further embodiment similar to that shown in Figs. 1a and 3a, rotor 126 is replaced by a cylindrical roller having a deep peripheral groove, and rotor 128 by a cylindrical smooth-surfaced rotor. Specification 631,061 is referred to.